Volume III • Number 3 • September-December 2009 ISSN: 1887 ...€¦ · Cytomegalovirus and Epstein-Barr Virus Infection in Pediatric Liver Transplants Esteban Frauca, Loreto Hierro

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Monitoring Regulatory T-Cells after Transplantation: Is It Useful?

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The Importance of Preserving Kidney Function after Heart Transplantation

Luis Almenar Bonet, Josep Navarro-Manchón and Luis Martínez-Dolz129

Anemia after Kidney and Other Solid Organ Transplantation

Mariarosaria Campise137

The Myth of Bioequivalence

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Cytomegalovirus and Epstein-Barr Virus Infection in Pediatric Liver Transplants

Esteban Frauca, Loreto Hierro and Paloma Jara153

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Kathryn Brown, Wilson Wong: Regulatory T-cells in transplantation

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Monitoring Regulatory T-Cells after Transplantation: Is It Useful?Kathryn Brown and Wilson Wong

MRC Centre for Transplantation, King’s College London School of Medicine at Guy’s, King’s and St Thomas’ Hospitals, London, UK

trends in transplant. 2009;3:119-28

Correspondence to:

Wilson Wong

mRC Centre for transplantation

5th Floor, tower Wing

Great maze Pond

London Se1 9Rt, UK

e-mail: [email protected]

Abstract

Currently, the gold standard for confirmation of rejection episodes in transplanted organs is histologic analysis of biopsy samples. There is no method to evaluate the risk of rejection in patients or to identify those who might be weaned off immunosuppression entirely. The development of biomarkers for use in transplantation would help achieve this goal of tailored immunosuppressive treatment for individual patients. Markers of regulatory T-cells, with their role in regulating the alloimmune response, have been investigated for their usefulness in this situation. This review will discuss the studies to date on the diagnostic and prognostic potential of regulatory T-cells in organ transplantation. (Trends in Transplant. 2009;3:119-28)

Corresponding author: Wilson Wong, [email protected]

Key words

Regulatory T-cells. FOXP3. Rejection. Graft outcome.

Introduction

Surveillance of solid organ transplants, such as kidney and liver, for rejection and evaluation of graft function is routinely per-formed through functional parameters such as plasma creatinine and liver enzymes, respec-tively. Any deterioration in function in the ab-sence of any other obvious causes usually prompts a biopsy to exclude rejection, es-pecially within the first year of transplanta-tion when the risk is high. This process has

several disadvantages. Firstly, the biopsy procedure carries risks of complications, most seriously bleeding from the biopsy site, which may lead to graft loss or even death. Secondly, sampling error may result in inaccurate representation of the organ graft as a whole. Thirdly, by the time the trans-planted organ is functionally compromised, irreversible tissue damage may have already taken place. The ideal method for monitoring rejection would be noninvasive and could de-tect rejection early. In the absence of such a monitoring method, histologic examination of biopsy samples remains the gold standard. It would be ideal to develop a more sophisti-cated screening method for rejection so that unnecessary biopsies could be avoided. In addition, it would be useful to establish the immunologic risks of individual patients after organ transplantation so that immunosuppres-sive therapy could be tailored accordingly. As

trends in transplantation 2009;3

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rejection is primarily an immune-mediated re-sponse, measurement of immunologic param-eters has the potential to be developed to serve these purposes.

Biomarkers and immunologic risk

A large amount of effort has been de-voted to the search for biomarkers (defined as a biological molecule whose presence can indicate a disease state or a high likelihood/risk of developing a disease or a specific dis-ease phenotype1) in many disease states and the field of transplantation is no exception. Initial studies concentrated on analyzing a few candidate genes such as the mediators of cy-totoxic T-cell killing perforin and granzyme B2,3. More recently, with advances in technology, there has been an increase in microarray based gene expression profiling, which exam-ines the whole genome and does not require the identification of a possible target4.

The identification of one biomarker, or more likely a panel of biomarkers, to detect a rejection episode would not only allow earlier diagnosis and therefore intervention, but may also identify patients with different levels of risk by providing information on the antidonor response of the recipient.

A percentage of patients who discon-tinue their immunosuppression do not reject their grafts. This phenomenon is more com-mon in liver transplant patients5-7, but also occurs in recipients of kidney transplants, al-though much less frequently8,9. Much work has gone into defining a “tolerogenic profile”, and this may allow not only the use of lower doses of immunosuppression in patients with tolerogenic profiles, but possibly the weaning of these patients off immunosuppression en-tirely. In contrast, patients at an increased risk of rejection according to the biomarker profile could be maintained on more intense immu-nosuppressive regimes to prevent rejection.

Currently, there is no way of predicting what level of immunosuppression a patient will need, which inevitably leads to some patients being over-immunosuppressed while others are under-immunosuppressed. The develop-ment of biomarkers is the first step to provid-ing tailored immunosuppressive therapy for individual patients.

Regulatory T-cells

The importance of regulatory T-cells (Treg) in tolerance models makes their surface or intracellular markers obvious candidates to provide a biomarker for transplantation. The characteristics of these cells and their role in the induction and maintenance of tolerance have been discussed elsewhere10-12. Although the vast majority of organ recipients are not truly tolerant of their grafts, Treg may still play an important role in the prevention of rejection, adjuvant to the immunosuppressive drugs used in the clinic. If so, monitoring their activ-ity in transplant recipients may provide useful immunologic information. This review will focus on their diagnostic potential, both in terms of aiding the diagnosis of rejection and provid-ing an indication of prognosis and information to aid tailoring immunosuppressive therapy for individual patients.

To monitor Treg, a robust marker should ideally be available. Unfortunately, a definitive marker for Treg in humans is yet to be found. The classic Treg are enriched within the CD4+CD25+ T-cell population13,14. To date, the most reliable marker available is forkhead box p3 (FOXP3), a member of the forkhead/winged helix family of transcription fac-tors15-17. In mice, Foxp3 is a specific marker of Treg

15-17, however in humans this transcrip-tion factor is also transiently expressed in non-regulatory T-cells upon activation18. Other markers used to identify Treg include CD45RB19,20, CTLA-421,22, GITR23-25, CD12226, CD10327, and galectin-1028, and the absence


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of CD127 can also indicate a regulatory phe-notype29,30. A combination of these markers may be the best way of identifying Treg.

The use of FOXP3 as a biomarker has been investigated in several aspects of trans-plantation: the diagnosis of rejection; the prediction of rejection and the outcome of a rejection episode; the presence of toler-ance; and involvement in graft-versus-host disease (GVHD).

Using regulatory T-cells to diagnose rejection

Given their potential to regulate allore-active T-cells, the presence of Treg in higher numbers should, in theory, exert a graft-pro-tective effect. Conversely, low numbers of Treg may suggest rejection.

Intragraft Treg/FOXP3

Results from these studies are summa-rized in table 1. Aquino-Dias, et al. studied kidney allografts that had suffered from de-layed graft function. The levels of FOXP3 mRNA were paradoxically significantly higher in those patients undergoing acute rejection, and indeed were a more reliable marker of rejection than either of the cytotoxic mediators perforin and granzyme B31. A separate com-parison of kidney transplant recipients with acute rejection and borderline changes found that again FOXP3 mRNA levels were higher in the rejection group32.

High FOXP3 mRNA levels have also been found to be predictive of rejection in liver allografts33. However, FOXP3 levels were also elevated during hepatitis C virus infection, suggesting that FOXP3 would not provide the

Table 1. Summary of the use of FOXP3 mRNA measurement in human solid organ transplant recipients during rejection episodes to aid diagnosis or as a predictor of outcome

Author Organ Sample source (factor measured)

No. of patients with rejection/total

Diagnostic of rejection?

Predictive of better/worse outcome?

Aquino-Dias, et al.31 Kidney Intragraft (mRNA) 20/75 Yes

Blood (mRNA) 20/75 Yes

Urine (mRNA 20/75 Yes

Ashton-Chess, et al.61 Kidney Intragraft (mRNA) 14/48 No

Blood (mRNA) 15/205 No

Grimbert, et al.32 Kidney Intragraft (mRNA) 15 BL/11 AR/36 total Yes

Mansour, et al.47 Kidney Intragraft (mRNA) 21/46 Better

Bestard, et al.48 Kidney Intragraft (cell no.) 37 Better

Bunnag, et al.45 Kidney Intragraft (mRNA) 31/95 Yes No

Veronese, et al.44 Kidney Intragraft (cell no.) 41/73 Yes Worse

Martin, et al.46 Kidney Intragraft (cell no.) 17/17 N/A Better

Muthukumar, et al.51 Kidney Urine (mRNA) 36/83 Yes Better

Demirkiran, et al.33 Liver Intragraft (mRNA) 3/20 Yes

Sakamoto, et al.49 Liver Blood (mRNA) 4/15 Better

Dijke, et al.34 Heart Intragraft (mRNA) 26/41 Yes

Heart Blood (mRNA) 26/41 No


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level of specificity required. Levels of FOXP3 mRNA have also been examined in heart transplant recipients34. Again, higher FOXP3 mRNA levels were present in the 26 acutely rejecting patients, compared to the 15 pa-tients without rejection.

The increase in Treg in rejection proba-bly reflects an overall increase in the immune response, with Treg being a portion of this, rather than acting in its graft-protective ca-pacity.

There is now increasing evidence that intragraft mRNA levels of FOXP3 do seem to be a good indicator of acute rejection. How-ever, to measure intragraft mRNA, biopsies must still be performed and, so, rejection can be diagnosed by histologic examination, which is still regarded as the gold standard. Therefore, in this respect, it serves little clini-cal purpose but is likely to remain as a useful research tool. Measuring FOXP3 mRNA levels in peripheral blood or urine (in the case of kidney transplantation) may circumvent this problem.

Peripheral blood and urine Treg/FOXP3

Aquino-Dias, et al., as well as studying intragraft FOXP3 mRNA, measured peripheral blood and urine FOXP3 mRNA levels in their cohort of patients with delayed graft function. They found that, as with intragraft FOXP3, mRNA levels of FOXP3 in blood and urine were significantly higher in the group under-going acute rejection31, with sensitivity and specificity in blood of 94 and 95%, respec-tively, while both corresponding figures in urine were 100%. Satoda, et al. made a simi-lar finding in a miniature swine model of lung transplantation35.

In contrast, no difference in the levels of FOXP3 mRNA were found in the blood of

heart transplant recipients, despite there being a difference in intragraft FOXP334. Similar find-ings were made in liver transplant recipients33. This may be due to the egress of these cells out of the blood and into the graft.

Peripheral blood and urine markers of Treg therefore appear to have potential to be used in the diagnosis of acute rejection of kidney, and potentially lung, transplants, al-though they have not proven useful so far in heart or liver transplantation. However, the number of patients in the study is small and needs to be confirmed by others. The sensitiv-ity and specificity of 100% in urine observed in the study is very impressive; it is difficult to envisage any tests with such high accuracies. Expansion of the cohort size is likely to reduce these figures. Nonetheless, urinary FOXP3 mRNA level should prove to be a useful mark-er in this respect.

The development of this method would allow a quick, noninvasive screening test for rejection, and Treg levels could be monitored alongside functional indicators such as plas-ma creatinine, allowing a patient’s immuno-logic status to be measured over time, and correlated to graft function.

Stem cell transplantation

The possibility of using Treg to diagnose GVHD in recipients of allogeneic stem cell transplants has also been explored. In con-trast to the situation with acute rejection of solid organ transplants, FOXP3 mRNA levels were found to be significantly reduced in all forms (acute, chronic, allo, auto) of GVHD in two independent studies36,37. These data were contradicted by Meignin, et al., who found no difference in blood mRNA FOXP3 levels be-tween patients with or without GVHD38. More work will need to be carried out to clarify the situation, although Rieger, et al. examined FOXP3+ cells in intestinal GVHD lesions and


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found evidence to support the hypothesis that lower numbers of FOXP3+ cells (relative to CD8+ cells) is indicative of GVHD39.

Other studies have been carried out to investigate Treg in GVHD, but these have used CD25 (in combination with CD4) to identify Treg

40-43. Again, results from these studies have been contradictory, suggesting that CD25, with its expression on activated T-cells, is not a specific enough marker of Treg.

Regulatory T-cells as predictors of rejection/rejection outcome

Intragraft

The presence of Treg in biopsies ap-pears to indicate rejection, presumably by revealing the extent of the alloimmune re-sponse. It may be expected that, further to this, higher levels of FOXP3 may indicate a better-regulated immune response and there-fore predict a better outcome of the rejection episode. Data acquired so far is summarized in table 1.

This theory was contradicted by data acquired by Veronese, et al., who found by immunohistochemistry that, as expected, the 41 kidney allografts with acute cellular rejec-tion had significantly more FOXP3+ cells than the 32 patients with acute humoral rejection44. However, in the group with acute cellular re-jection, the higher the number of FOXP3+ cells the worse the outcome. The numbers of CD4+ and CD8+ cells were also higher, suggesting that the higher number of FOXP3+ cells rep-resented merely a more vigorous alloimmune response rather than a disproportionate num-ber of FOXP3+ cells. They also found FOXP3+ T-cells infiltrating tubules, and coined the phrase Treg tubulitis44. Indeed, they found that FOXP3+ cells were more likely to infiltrate tubules than CD4+FOXP3– cells. This infiltra-tion of tubules provides a mechanism for the

entry of Treg into the urine (see next section). A separate independent study on FOXP3 mRNA in renal biopsies also found that FOXP3 mRNA levels did not correlate with good graft outcome45.

Contrasting data came from a much smaller study by Martin, et al., who showed that of 17 kidney transplant biopsies studied, three underwent rejection resulting in graft loss within the first year46. These three sam-ples had no FOXP3+ cells when biopsied dur-ing the early stages of acute rejection. This study, although small, suggests that it may be worthwhile to conduct further investigations.

Levels of FOXP3 may be able to predict future rejection episodes in certain patients. A study of renal allografts with borderline changes determined that those grafts which did not progress to rejection had significantly higher levels of FOXP3 mRNA than those grafts which did progress47. Therefore, in this particular group of patients with borderline changes, FOXP3 may be indicative of the like-lihood of progression to rejection. Similarly, in a study of 37 cases of kidney biopsies with subclinical rejection, higher numbers of FOXP3+ predicted better graft function48. FOXP3 may be useful in defining the immunologic status in these patients, which are currently not well understood, and predicting the chances of a rejection episode so that immunosuppression can be altered accordingly.

Peripheral blood

A time-course study was carried out on levels of FOXP3 mRNA in blood from liver transplant recipients. In all 15 patients, FOXP3 mRNA levels increased by day 7 posttrans-plantation, and then returned to baseline by day 28. In the four patients who went on to de-velop T-cell mediated rejection within 60 days, FOXP3 mRNA levels returned to baseline by day 14 posttransplantation49. This study was


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small and did not show any statistically sig-nificant differences. However, it does suggest that FOXP3, as part of a large panel of bio-markers, may be useful in the prediction of rejection.

Peripheral blood from heart transplant recipients pretransplantation was collected and Treg function examined. The CD4+CD25hi cells from blood samples taken pretransplan-tation from heart transplant recipients who went on to develop acute rejection were less suppressive than those from non-rejecters50. However, this does limit the usefulness of Treg in blood to predict heart rejection as a func-tional assay of Treg is probably too time-con-suming to be performed clinically.

Urine

Muthukumar, et al. conducted a study into FOXP3 mRNA in the urine of kidney trans-plant recipients51. Again confirming the ability of FOXP3 mRNA levels to diagnose rejection, FOXP3 mRNA was higher in patients with re-jection than those without and controls. In-creased levels of FOXP3 mRNA within the urine of the rejection group was associated with better graft outcome. It is possible that the difference between the Veronese, et al. and Muthukumar, et al. data is due to the fact that the urinary mRNA levels represent only those Treg that infiltrate tubules within the kidney.

Stem cell transplantation

To predict GVHD after stem cell trans-plantation, donor cell infiltrates, rather than the peripheral blood of recipients, were ana-lyzed for FOXP3. Two independent studies on donor infiltrate in HLA-identical stem cell transplants showed that patients who received infiltrate with low numbers of CD4+FOXP3+ cells were more likely to suffer from severe GVHD52,53.

A separate study used CD4 and CD25 to de-fine Treg, and found, conversely, that GVHD was associated with high numbers of CD4+CD25+ cells within the donor infiltrate54. However, this again may be due to the use of CD25 as a marker of Treg, as it was shown by Rezvani et al. that numbers of CD4+FOXP3+ and CD4+CD25+ cells in donor cell infiltrates were inversely correlated52.

The ability of FOXP3 to predict graft outcome in those patients undergoing rejec-tion remains unclear. It does appear though that FOXP3 has greater potential as a predic-tor of future rejection episodes, both in kidney and liver transplant recipients, and may help to more successfully diagnose those patients with only slight histologic changes. FOXP3 within the donor infiltrate may also be useful in the prediction of GVHD.

Regulatory T-cells as biomarker of tolerance

As discussed earlier, some patients who discontinue their immunosuppression do not reject their grafts. This is known as spon-taneous operational tolerance (SPOT), and great effort has gone into attempts to charac-terize these patients and define a tolerogenic profile. The results to date are summarized in table 2. This is a difficult task, given the rarity of these patients and the problem of obtaining samples from them.

Intragraft

Sachs, et al. have used a non-myeloab-lative conditioning regime prior to kidney and bone marrow transplantation, which has al-lowed them to discontinue immunosuppres-sion at about one year post transplantation55. Grafts continued to function well until studied here at 2-5.3 years posttransplantation. Levels of FOXP3 mRNA in kidney biopsies were


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about six-times higher in the immunosuppres-sion-free group than in the group with good graft function that were still receiving immuno-suppressive therapy. This indicates that in the absence of immunosuppression, bone mar-row transplantation can induce a regulatory phenotype. However, the number of patients is small and needs to be extended to confirm this important finding.

Given the ethical considerations of per-forming kidney biopsies on patients with good graft function, we56 and others57 have used a murine kidney transplant model, in which DBA/2 kidneys are spontaneously accepted by C57BL/6 recipients. High numbers of Foxp3+ cells were found in the graft and spleen of these mice. Although allografts were tolerated initially, some recipients underwent chronic rejection resulting in graft loss, and kidney allografts from these mice contained low numbers of Foxp3+ cells56.

In liver transplant recipients, FOXP3 mRNA levels in biopsies were higher in grafts from SPOT patients than in those being main-tained on immunosuppression but similar to those in chronically rejected grafts58. Howev-er, when the FOXP3 was examined at the pro-tein level, the number of FOXP3+ cells was significantly higher in SPOT patients than in both those on immunosuppression and those that had been chronically rejected.

The reason for this discrepancy is unknown as other studies have found good correlation between mRNA and cell numbers.

Peripheral blood

Louis, et al. investigated CD4+CD25hi cell numbers and FOXP3 mRNA in SPOT kidney transplant patients59. Numbers of CD4+CD25hi cells and FOXP3 mRNA levels were similar in SPOT patients and those on immunosuppression. However, cell numbers and mRNA levels were lower in chronically rejecting patients. Similar results were ob-tained in a separate study59, and Brouard, et al. reached the same conclusion using pe-ripheral blood gene expression profiles60. This ability to distinguish chronic rejection using Treg has been contradicted, however, by a study by Ashton-Chess, et al.61.

A Europe-wide study also analyzed mRNA levels in SPOT kidney transplant re-cipients62. They found that although FOXP3 mRNA levels alone could not be used to dis-tinguish SPOT patients, this group did have a significantly higher ratio of FOXP3 to alpha-mannosidase mRNA than chronically rejecting patients and those with stable function on im-munosuppression. This confirms the impor-tance of examining several parameters when judging the immunologic profile of a patient.

Table 2. Summary of the use of FOXP3 mRNA measurement in SPOT patients as a biomarker of tolerance

Author Organ Sample source No. of SPOT patients/total Marker of tolerance?

Kawai, et al.55 Kidney Intragraft (mRNA) 6/14 Yes

Louis, et al.59 Kidney Blood (cell no. and mRNA) 8/65 No

Alvarez, et al.67 Kidney Blood (mRNA) 3/40 No

Brouard, et al.60 Kidney Blood (mRNA) 17/75 No

Li, et al.58 Liver Intragraft (mRNA) 28/64 No

Intragraft (cell no.) 28/64 Yes

Pons, et al.64 Liver Blood (cell no. and mRNA) 5/12 Yes

SPOT: spontaneous operational tolerance.


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Peripheral blood from liver transplant SPOT patients contained higher numbers of CD4+CD25+ cells than liver transplant recipi-ents on immunosuppression63. In addition, CD4+CD25hi cell numbers and FOXP3 mRNA levels increased and remained high upon withdrawal of immunosuppression in five liver transplant recipients who did not reject their grafts. In the seven patients who underwent rejection upon withdrawal, neither CD4+CD25hi cell numbers nor FOXP3 mRNA levels in-creased64. Therefore, Treg may be more indica-tive of tolerance in liver compared to kidney transplant recipients, and could possibly be used to identify the significant percentage of liver transplant recipients currently on immuno-suppression who could be candidates for wean-ing (estimated to be up to 20%65), and to deter-mine the success, or failure, of this process.

Conclusions

Although a great deal of conflicting data has been published on the use of FOXP3 as a biomarker in transplantation, it seems that using FOXP3 mRNA levels in peripheral blood could become a reliable method of screening for acute rejection of kidney grafts and GVHD after stem cell transplantation. Larger scale studies involving more patients from multiple centers are urgently needed to establish this. However, it is unlikely that monitoring of Treg will completely replace histologic examination of the transplanted organs, but may provide additional information on the immune status of the recipients during rejection episodes. In those kidney transplant patients with only slight histologic abnormalities, FOXP3 analysis may help to clarify the status of the immune re-sponse and predict future rejection episodes. However, the potential of FOXP3 as a predic-tor of graft outcome is still unclear, given the number of small studies yielding conflicting results. Again, cooperation between different transplant centers to perform a large multi-centre study would clarify this issue.

Some of the conflicting data described above may be related to other factors that affect FOXP3 expression. Two studies have shown that FOXP3 is increased with time after transplantation45,61. Factors such as these must be considered before FOXP3 is used for clinical diagnostic purposes.

It is very unlikely that one single bio-marker, no matter how important in the alloim-mune response, will be able to specifically and sensitively predict rejection and graft out-come. A panel of biomarkers from different facets of the immune response is probably the way forward. Genes which have shown prom-ise include those for perforin, granzyme B, and granulysin, which reflect cytotoxic T-cell activity; NKG2D, an activating receptor on natural killer cells and T-cells; cytokines such as interferon-γ; and the chemokine IP-10 (re-viewed66). It is likely that FOXP3, or more de-finitive marker(s) of Treg, will be an important component of this panel. Much more work needs to be done in this area, but the ultimate goal is within our grasp. When achieved, the greatest potential for this technique would be the assessment of the individual immunologic risks of transplant recipients, thus enabling the tailoring of immunosuppression to maximize graft outcome while minimizing side effects.

Acknowledgements

Work from the authors relating to this review was funded by a Genzyme Renal Innovations Program award. The authors declare no potential conflict of interest.

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14. Sakaguchi S, Sakaguchi N, Asano M, Itoh M, Toda M. Im-munologic self-tolerance maintained by activated T cells expressing IL-2 receptor a-chains (CD25). Breakdown of a single mechanism of self-tolerance causes various autoim-mune diseases. J Immunol. 1995;155:1151-64.

15. Hori S, Namura T, Sakaguchi S. Control of regulatory T cell development by the transcription factor Foxp3. Science. 2003;299:1057-61.

16. Fontenot JD, Gavin MA, Rudensky AY. Foxp3 programs the development and function of CD4+CD25+ regulatory T cells. Nat Immunol. 2003;4:330-6.

17. Khattri R, Cox T, Yasayko SA, Ramsdell F. An essential role for Scurfin in CD4+CD25+ regulatory T cells. Nat Immunol. 2003;4:337-42.

18. Morgan ME, van Bilsen JH, Bakker AM, et al. Expression of FOXP3 mRNA is not confined to CD4+CD25+ T regulatory cells in humans. Hum Immunol. 2005;66:13-20.

19. Morrissey PJ, Charrier K, Braddy S, Liggitt D, Watson JD. CD4+ T cells that express high levels of CD45RB induce wasting disease when transferred into congenic severe combined immunodeficient mice. Disease development is prevented by cotransfer of purified CD4+ T cells. J Exp Med. 1993;178:237-44.

20. Powrie F, Leach MW, Mauze S, Caddle LB, Coffman RL. Phenotypically distinct subsets of CD4+ T cells induce or protect from chronic intestinal inflammation in C. B-17 scid mice. Int Immunol. 1993;5:1461-71.

21. Read S, Malmstrom V, Powrie F. Cytotoxic T lymphocyte-associated antigen 4 plays an essential role in the function of CD25+CD4+ regulatory cells that control intestinal inflam-mation. J Exp Med. 2000;192:295-302.

22. Takahashi T, Tagami T, Yamazaki S, et al. Immunologic self-tolerance maintained by CD25(+)CD4(+) regulatory T cells constitutively expressing cytotoxic T lymphocyte-associated antigen 4. J Exp Med. 2000;192:303-10.

23. Gavin MA, Clarke SR, Negrou E, Gallegos A, Rudensky A. Homeostasis and anergy of CD4(+)CD25(+) suppressor T cells in vivo. Nat Immunol. 2002;3:33-41.

24. McHugh RS, Whitters MJ, Piccirillo CA, et al. CD4(+)CD25(+) immunoregulatory T cells: gene expression analysis reveals a functional role for the glucocorticoid-induced TNF recep-tor. Immunity. 2002;16:311-23.

25. Shimizu J, Yamazaki S, Takahashi T, Ishida Y, Sakaguchi S. Stimulation of CD25(+)CD4(+) regulatory T cells through GITR breaks immunological self-tolerance. Nat Immunol. 2002;3:135-42.

26. Stephens LA, Mottet C, Mason D, Powrie F. Human CD4(+)CD25(+) thymocytes and peripheral T cells have immune sup-pressive activity in vitro. Eur J Immunol. 2001;31:1247-54.

27. Suffia I, Reckling SK, Salay G, Belkaid Y. A role for CD103 in the retention of CD4+CD25+ Treg and control of leishma-nia major infection. J Immunol. 2005;174:5444-55.

28. Kubach J, Lutter P, Bopp T, et al. Human CD4+CD25+ regulatory T cells: proteome analysis identifies galectin-10 as a novel marker essential for their anergy and suppressive function. Blood. 2007;110:1550-8.

29. Liu W, Putnam AL, Xu-yu Z, et al. CD127 expression in-versely correlates with FoxP3 and suppressive function of human CD4+ Treg cells. J Exp Med. 2006;203:1701-11.

30. Seddiki N, Santner-Nanan B, Martinson J, et al. Expression of interleukin (IL)-2 and IL-7 receptors discriminates be-tween human regulatory and activated T cells. J Exp Med. 2006;203:1693-700.

31. Aquino-Dias EC, Joelsons G, da Silva DM, et al. Non-inva-sive diagnosis of acute rejection in kidney transplants with delayed graft function. Kidney Int. 2008;73:877-84. *A sys-tematic investigation of blood, urine and intragraft mRNA levels of various markers including FOXP3 in kidney trans-plant recipients showing that FOXP3 was the most accurate marker studied of rejection with high sensitivity and spec-ificity.

32. Grimbert P, Mansour H, Desvaux D, et al. The regulatory/cytotoxic graft-infiltrating T cells differentiate renal allograft borderline change from acute rejection. Transplantation. 2007;83:341-6.

33. Demirkiran A, Baan CC, Kok A, Metselaar HJ, Tilanus HW, van der Laan LJ. Intrahepatic detection of FOXP3 gene expression after liver transplantation using minimally inva-sive aspiration biopsy. Transplantation. 2007;83:819-23.

34. Dijke IE, Caliskan K, Korevaar SS, et al. FOXP3 mRNA expres-sion analysis in the peripheral blood and allograft of heart transplant patients. Transplant Immunol. 2008;18:250-4.

35. Satoda N, Shoji T, Wu Y, et al. Value of FOXP3 expression in peripheral blood as rejection marker after miniature swine lung transplantation. J Heart Lung Transplant. 2008;27:1293-301.

36. Miura Y, Thoburn CJ, Bright EC, et al. Association of Foxp3 regulatory gene expression with graft-versus-host disease. Blood. 2004;104:2187-93.

37. Zorn E, Kim HT, Lee SJ, et al. Reduced frequency of FOXP3+ CD4+CD25+ regulatory T cells in patients with chronic graft-versus-host disease. Blood. 2005;106:2903-11.

38. Meignin V, de Latour RP, Zuber J, et al. Numbers of Foxp3-expressing CD4+CD25high T cells do not correlate with the establishment of long-term tolerance after allogeneic stem cell transplantation. Exp Hematol. 2005;33):894-900.

39. Rieger K, Loddenkemper C, Maul J, et al. Mucosal FOXP3+ regulatory T cells are numerically deficient in acute and chronic GvHD. Blood. 2006;107:1717-23.

40. Clark FJ, Gregg R, Piper K, et al. Chronic graft-versus-host disease is associated with increased numbers of peripheral blood CD4+CD25high regulatory T cells. Blood. 2004;103: 2410-16.

41. Sanchez J, Casano J, Alvarez MA, et al. Kinetic of regula-tory CD25high and activated CD134+ (OX40) T lymphocytes during acute and chronic graft-versus-host disease after allogeneic bone marrow transplantation. Br J Haematol. 2004;126:697-703.

42. Schneider M, Munder M, Karakhanova S, Ho AD, Goerner M. The initial phase of graft-versus-host disease is associ-ated with a decrease of CD4+CD25+ regulatory T cells in the peripheral blood of patients after allogeneic stem cell trans-plantation. Clin Lab Haematol. 2006;28:382-90.

43. Nadal E, Garin M, Kaeda J, et al. Increased frequencies of CD4+CD25high Tregs correlate with disease relapse after allogeneic stem cell transplantation for chronic myeloid leu-kemia. Leukemia. 2007;21:472-9.

44. Veronese F, Rotman S, Smith RN, et al. Pathological and clinical correlates of FOXP3+ cells in renal allografts during acute rejection. Am J Transplant. 2007;7:914-22. **The au-thors detected the presence of FOXP3 positive cells infiltrat-ing tubules and coined the phrase Treg tubulitis. This forms the physical basis for the appearance of FOXP3 mRNA in the urine studied by several other investigators.


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45. Bunnag S, Allanach K, Jhangri GS, et al. FOXP3 expression in human kidney transplant biopsies is associated with rejec-tion and time post transplant but not with favorable out-comes. Am J Transplant. 2008;8:1423-33.

46. Martin L, de la Vega MF, Bocrie O, et al. Detection of Foxp3+ cells on biopsies of kidney transplants with early acute rejec-tion. Transplant Proc. 2007;39:2586-8.

47. Mansour H, Homs S, Desvaux D, et al. Intragraft levels of Foxp3 mRNA predict progression in renal transplants with borderline change. J Am Soc Nephrol. 2008;19:2277-81.

48. Bestard O, Cruzado JM, Rama I, et al. Presence of FoxP3+ regulatory T cells predicts outcome of subclini-cal rejection of renal allografts. J Am Soc Nephrol. 2008; 19:2020-6.

49. Sakamoto R, Asonuma K, Zeledon Ramirez ME, et al. Forkhead box P3 (FOXP3) mRNA expression immediately after living-donor liver transplant. Exp Clin Transplant. 2009;7:8-12.

50. Dijke I E, Korevaar SS, Caliskan K, et al. Inadequate immune regulatory function of CD4+CD25bright+FoxP3+ T cells in heart transplant patients who experience acute cellular re-jection. Transplantation. 2009;87:1191-200.

51. Muthukumar T, Dadhania D, Ding R, et al. Messenger RNA for FOXP3 in the urine of renal-allograft recipients. N Engl J Med. 2005;353:2342-51. **Using real time RT-PCR to mea-sure the level of FOXP3 mRNA in urine of recipients of kid-ney transplant, the authors found that high levels were as-sociated with better outcome.

52. Rezvani K, Mielke S, Ahmadzadeh M, et al. High donor FOXP3-positive regulatory T-cell (Treg) content is associat-ed with a low risk of GVHD following HLA-matched alloge-neic SCT. Blood. 2006;108:1291-7.

53. Wolf D, Wolf AM, Fong D, et al. Regulatory T-cells in the graft and the risk of acute graft-versus-host disease after allogeneic stem cell transplantation. Transplantation. 2007;83:1107-13.

54. Stanzani M, Martins SLR, Saliba RM, et al. CD25 expression on donor CD4+ or CD8+ T cells is associated with an in-creased risk for graft-versus-host disease after HLA-identi-cal stem cell transplantation in humans. Blood. 2004;103: 1140-6.

55. Kawai T, Cosimi AB, Spitzer TR, et al. HLA-mismatched renal transplantation without maintenance immunosuppres-sion. N Engl J Med. 2008;358:353-61.

56. Brown K, Moxham V, Karegli J, et al. Ultra-localization of Foxp3+ T cells within renal allografts shows infiltration of tu-bules mimicking rejection. Am J Pathol. 2007;171:1915-22.

57. Bickerstaff AA, Wang J-J, Pelletier RP, Orosz CG. Murine renal allografts: spontaneous acceptance is associated with regu-lated T cell-mediated immunity. J Immunol. 2001;167:4821-7.

58. Li Y, Zhao X, Cheng D, et al. The presence of Foxp3 ex-pressing T cells within grafts of tolerant human liver trans-plant recipients. Transplantation. 2008;86:1837-43.

59. Louis S, Braudeau C, Giral M, et al. Contrasting CD25hiCD4+ T cells/FOXP3 patterns in chronic rejection and operational drug-free tolerance. Transplantation. 2006;81:398-407.

60. Brouard S, Mansfield E, Braud C, et al. Identification of a peripheral blood transcriptional biomarker panel associated with operational renal allograft tolerance. Proc Nat Acad Sci USA. 2007;104:15448-53.

61. Ashton-Chess J, Dugast E, Colvin RB, et al. Regulatory, effector, and cytotoxic T cell profiles in long-term kidney transplant patients. J Am Soc Nephrol. 2009;20:1113-22.

62. Hernandez-Fuentes M, Sawitszki B, Sagoo P, et al. Indices of tolerance: interim report (abstract). Am J Transplant. 2006;6:403.

63. Martinez-Llordella M, Puig-Pey I, Orlando G, et al. Multipa-rameter immune profiling of operational tolerance in liver transplantation. Am J Transplant. 2007;7:309-19.

64. Pons J A, Revilla-Nuin B, Baroja-Mazo A, et al. FoxP3 in peripheral blood is associated with operational tolerance in liver transplant patients during immunosuppression with-drawal. Transplantation. 2008;86:1370-8.

65. Lerut J, Sanchez-Fueyo A. An appraisal of tolerance in liver transplantation. Am J Transplant. 2006;6:1774-80.

66. Anglicheau D, Suthanthiran M. Noninvasive prediction of organ graft rejection and outcome using gene expression patterns. Transplantation. 2008;86:192-9.

67. Alvarez CM, Opelz G, Garcia LF, Susal C. Expression of regulatory T-cell-related molecule genes and clinical out-come in kidney transplant recipients. Transplantation. 2009;87:857-63.

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The Importance of Preserving Kidney Function after Heart TransplantationLuis Almenar Bonet, Josep Navarro-Manchón and Luis Martínez-Dolz

Heart Failure and Transplant Unit, Department of Cardiology, La Fe University Hospital, Valencia, Spain

AbstractHeart transplantation has significantly improved survival in recent years. However, it is not without complications, among which renal dysfunction is one of the most significant. The prevalence of renal dysfunction at seven years is 60% (GFR < 60 ml/min/1.73m2) and the prevalence of severe renal dysfunction at ten years is 10.4% (GFR < 30 ml/min/1.73m2). The presence of renal dysfunction at one year is associated with increased medium/long-term mortality. Most patients receiving a heart transplant have normal renal function, but suffer a significant deterioration in renal function over the first year posttransplantation, which later stabilizes and progresses slowly toward end-stage renal disease. There are many preoperative, intraoperative, perioperative, and medium/long-term factors that determine the development of renal dysfunction, but their presence is usually attributed to calcineurin inhibitors. Preoperative factors include advanced age, sex, diabetes mellitus, hypertension, hepatitis C virus, and especially renal dysfunction prior to heart transplantation. Among the most important intraoperative factors are hemorrhage, hypotension, hemolysis, and a need for vasopressor drugs. The most important postoperative factors are septic conditions, cytomegalovirus infection, and early exposure to calcineurin inhibitors. The long-term predisposing factors are dyslipidemia, diabetes, infections, hypertension, and the degree of exposure to calcineurin inhibitors.Calcineurin inhibitors are the drugs most commonly implicated in renal dysfunction. It as been suggested that tacrolimus may be less often associated with renal dysfunction than cyclosporine. An emerging strategy is to prolong induction with anti-interleukin-2 monoclonal antibodies and delay introduction of the calcineurin inhibitor in patients with reduced glomerular filtration rate at transplantation. If renal function subsequently recovers, the calcineurin inhibitor is introduced and, if any degree of renal dysfunction persists, an mTOR inhibitor or calcineurin inhibitor in lower doses can be administered.One of the major problems is the method for diagnosing renal dysfunction. Plasma creatinine has numerous limitations. Creatinine clearance requires 24-hour urine collection, while the use of formulas such as the Cockroft-Gault method and the MDRD-4 and measurement of cystatin


Correspondence to:Luis Almenar Bonet

Hospital Universitario La Fe

Servicio de Cardiología

Unidad de Insuficiencia Cardíaca y trasplante

Avda. Campanar, 21

46009 Valencia, españa



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Introduction

Heart transplantation (HT) is the indicat-ed treatment for severe, highly symptomatic heart failure without other medical or surgical options. This therapeutic technique has sur-vival rates at 1, 5, and 10 years of 90, 70, and 50%, respectively1. Nevertheless, it is not without problems due to graft rejection and the development of complications. One of the most significant complications is renal dys-function (RD).

A 30-60% prevalence of RD in HT re-cipients at seven years has been reported, considering RD as a serum creatinine > 1.5 mg/dl or a glomerular filtration rate (GFR) < 60 ml/min/1.73m2, respectively2,3. The incidence of RD measured by GFR is about 5% in the first year, with a 3-4% annual incidence from the second year onward. If we calculate the inci-dence of RD based on creatinine values, it is about 20% in the first year, followed by a 5% annual incidence one year after transplanta-tion4-6. In any case, the cumulative incidence of severe, chronic RD (GFR < 30 ml/min/1.73m2)

increases progressively over time, and is 4.2, 10.4, and 12.5% at 5, 10, and 15 years of HT7.

However, studies on the prevalence and incidence of RD in HT have the limitation of the heterogeneity in the definition of the concept itself of RD.

Morbidity and mortality from renal dysfunction

The impact of RD on mortality has been confirmed in multiple studies4,8-10. The classic study by Ojo, et al.4 was one of the first to report the impact of RD at one year on mortality for all types of nonrenal solid organ transplants (heart, lung, heart-lung, intestine, liver). Similarly, Arora, et al.8 showed that mortality increased as GFR declined at one year of HT. Several studies have shown the increase in mortality associated with the development of end-stage renal disease post-HT. In the multivariate analysis of the Spanish Registry of Heart Transplantation11, it was observed that RD and the need for dialysis post-HT were associated

C are alternative methods with some limitations. Inulin clearance remains the gold standard, but its use is limited by its labor intensiveness. There is also the possibility of performing a renal biopsy if the diagnosis is uncertain or to confirm the reversibility of renal damage.To prevent renal dysfunction, it is important to avoid all risk factors and predisposing conditions. Careful selection of recipients and management of cardiovascular risk factors prior to heart transplantation is essential. Patients should receive careful management, avoiding hypotensive episodes in the perioperative period. The emergence of new molecules (fenoldopam and dopexamine) to replace classic vasopressor agents requires further clinical studies.With the development of end-stage renal disease, dialysis and inclusion on the waiting list for kidney transplantation should be considered. There is growing evidence suggesting that if renal dysfunction is established at the time of heart transplantation, the patient should be considered for simultaneous heart-kidney transplantation. (Trends in Transplant. 2009;3:129-36)

Corresponding author: Luis Almenar Bonet, [email protected]

Key words

Renal dysfunction. Heart transplantation. Kidney function. End-stage renal disease.

Luis Almenar Bonet, et al.: Kidney Function and Heart Transplantation

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with increased mortality, especially in the me-dium/long term. In a French study, survival post-HT was statistically lower in patients who had to start a dialysis program12. In the Canadian Organ Replacement Registry, pa-tients on dialysis following HT had worse sur-vival than those not on dialysis. However, sur-vival was similar between patients with end-stage renal disease who underwent a kidney transplant after HT and those who did not require dialysis13.

In the different studies, the causes of mortality in patients with established RD were diverse, but one of the most important was sudden death8. It is well known that RD is associated with an increased prevalence of ischemic heart disease14. However, studies that have analyzed the presence of cardiac allograft vasculopathy (CAV) have not been able to demonstrate a relationship between RD and the development of CAV8. Perhaps, increased use of coronary intravascular ultra-sound (IVUS) will improve its diagnosis and allow new data to be provided on this issue.

Natural history of renal function after heart transplantation

Most patients receiving a solid organ transplant do so with normal or nearly normal renal function15. The course of renal function in the first year post-HT was shown to be crucial in a study where it was shown to follow a biphasic curve, with a 50% decrease in GFR in the first year, followed by stabilization and a subsequent slow but steady decline towards end-stage renal failure5. For this rea-son, progression of RD within the first year is key predictor of subsequent development of end-stage renal disease, the need for dialy-sis, and mortality, and its assessment at one year is fundamental for the prognosis of the patient4,8,16.

Pathophysiology and etiopathogenesis of renal dysfunction

Numerous studies have shown the del-eterious effect of calcineurin inhibitors on renal function17-20. Multiple mechanisms have been described by which calcineurin inhibitors contribute to RD. There is a drop in renal plasma flow, a loss of the filtration capacity by glomerular capillaries, vasoconstriction of afferent arterioles due to increased sympa-thetic tone, activation of the renin-angiotensin system, an altered balance between thrombox-ane and prostaglandins, an increased pro-duction of endothelin-1, and a decreased production of nitric oxide by endothelial cells21.

Although RD is usually attributed to the use of calcineurin inhibitors, it should be considered a multifactorial process. Thus, in a study in which a renal biopsy was performed on 24 HT recipients with end-stage renal failure, although 60% of the biopsies showed changes compatible with calcineurin inhibitor toxicity, the damage caused by other condi-tions such as hypertension, diabetes mellitus, and focal segmental glomerulosclerosis was observed in a considerable percentage of patients15.

Risk factors and clinical conditions predisposing to the development of renal dysfunction

The risk factors and clinical conditions associated with RD can be grouped into preoperative, intraoperative, postoperative, and medium/long term22. In general, the first three are not (or only slightly) modifiable factors and intervention is only possible on medium- and long-term predisposing factors. Among these, the most important is nephro-toxicity induced by immunosuppressant drugs, which we will review separately.


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Preoperative factors include ad-vanced age, sex, race, genetic factors, dia-betes mellitus23, arterial hypertension24, ischemic heart disease, and the presence of hepatitis C virus antibodies25. The effect of some cardiovascular risk factors may be minimized due to exclusion from the waiting list of patients with more rebellious arterial hypertension or with established diabetic retinopathy. In any case, it has been shown that one of the most important predictive factors is the presence of RD prior to trans-plantation7,22,26.

The most important intraoperative fac-tors are those that can lead to acute renal dysfunction during the surgical procedure. Thus, the presence of surgical hemorrhage, intraoperative hypotension, hemolysis by extracorporeal circulation and the need for vasopressor drug use can promote the devel-opment of RD22,27.

Postoperative factors include acute renal failure after surgery, septic conditions, cytomegalovirus infection, and early exposure to calcineurin inhibitors22,28. A study by this group (under review for publication) suggests that cytomegalovirus infection not only pre-disposes to the development of RD, but that prophylaxis with antivirals has a protective effect in preventing its development.

Medium- and long-term predisposing factors hold a prominent place because they usually involve factors or clinical condi-tions that are susceptible to some type of intervention. These include dyslipidemia29, proteinuria, infections (hepatitis B and C virus, cytomegalovirus), posttransplant arterial hypertension30, nephrotoxic drugs, and the degree of exposure to calcineurin inhibitor drugs22,28. As previously indicated, evaluation of renal function at one year post-HT is par-ticularly important because of its prognostic value4,8,16.

Immunosuppressant drugs and development of renal dysfunction

Patients may or may not receive induction therapy after HT, and usually receive mainte-nance immunosuppression with triple therapy consisting of a calcineurin inhibitor, an anti-proliferative drug, and a corticosteroid. There are few data in the literature regarding the effect of different induction drugs on renal function post-HT. There are publications suggesting that prolonging treatment with anti-CD25 antibodies (daclizumab and basi-liximab) and delaying introduction of the calcineurin inhibitor could preserve renal function to a greater extent in patients with reduced GFR at transplantation31-33. Regarding the antiproliferative drug, in a large multicenter trial it was shown that dose adjustment of the calcineurin inhibitor combined with intensi-fication of the less nephrotoxic medication (mycophenolate mofetil) was able to preserve renal function to a greater extent34. It has been suggested that the choice of mycophenolate mofetil, because it is associated with a lower number of rejections35, allows the dose of the calcineurin inhibitor to be reduced, therefore showing a protective effect on renal function when compared to azathioprine.

The detrimental effect of calcineurin inhibitors has been verified in numerous studies both in HT and other solid organ transplants, and constitutes one of the main determinants of posttransplant renal failure17-20. A recent analysis of the risk factors associated with the development of moderate-to-severe RD in the Spanish CAPRI registry determined that the choice of tacrolimus versus cyclosporine was a protective factor for its development2. In renal transplantation, the ELITE-Symphony study showed that a regimen of daclizumab, mycophenolate mofetil, and steroids in combi-nation with low-dose tacrolimus may be benefi-cial in terms of renal function, graft survival, and rejection rate as compared with low-dose


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cyclosporine, low-dose sirolimus, or standard-dose cyclosporine without induction36. However, before it can be stated that tacrolimus is associated with significantly decreased de-velopment of RD, specific studies designed for this purpose will probably be needed.

A new emerging strategy in the manage-ment of immunosuppression is the replacement or minimization of the dose of calcineurin inhibitor by an mTOR inhibitor (everolimus) with the aim of improving renal function37.

Measurements for estimation of renal function – Diagnosis

One of the most significant problems when determining incidence and prevalence is the definition itself of RD. There are numerous methods of estimating renal function, which have different advantages and disadvantages depending on their precision and difficulty to perform.

Determination of plasma creatinine is probably the most widely used method, but it has numerous limitations. It requires that loss of renal function is 50% in order to reflect significant changes in its values, so its utility for early diagnosis is limited38.

Creatinine clearance, which uses plasma and urinary concentrations of creatinine, is a more accurate predictor of renal function. However, it requires meticulous 24-hour urine collection, which hampers its use for the follow-up of outpatients38.

Calculation of glomerular filtration rate by indirect formulas has become one of the most widely used methods in recent years. The most important are the Cockroft-Gault formula39 and the Modification of Diet in Renal Disease (MDRD-4)40. The latter is the one recommended by the National Kidney Founda-tion in the Kidney Disease Outcomes Quality

Initiative (K/DOQI) guidelines41. The formulas permit earlier detection of RD, but are still an indirect method, with limitations in the calculation of glomerular filtration rate.

The use of cystatin C as a marker of renal function has been gaining importance in recent years. It is an endogenous molecule that is totally filtered by the glomerulus and is not reabsorbed or secreted. Its hypothetical advan-tage is that it is not affected by age, gender, or race, but studies are still needed to validate the utility of cystatin C in the setting of HT42-44.

However, the method considered the gold standard for calculation of glomerular filtration rate is clearance measured by inulin. Its complexity and laboriousness complicate its use45,46. In addition, there are other methods that use radiolabeled isotopes and nonradio-active contrast agents to estimate glomerular filtration rate, but again their complexity makes their use as markers impractical in routine clinical practice47,48. Although they are not parameters that directly estimate renal function, we should not forget the additional prognostic information offered by proteinuria and microal-buminuria49.

Lastly, the indication for renal biopsy should be determined by the nephrologist. Percutaneous computed tomography or ultra-sound-guided renal biopsy provides diagnos-tic, prognostic, and therapeutic information. In general, it is indicated if there is a suspicion of underlying disease other than chronic RD in the context of a nonrenal transplant, in the presence of altered urinary sediment, or to confirm the chronicity of the RD prior to switching to an mTOR inhibitor50.

Strategies to prevent renal dysfunction

Prevention of RD should begin with attempts to avoid all circumstances that may


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predispose to deterioration of renal function. Careful selection of recipients, as well as efforts to ensure that the end-stage heart failure patient arrives in the best possible condition to HT, are key measures to prevent long-term RD. As previously mentioned, the presence of prior RD is one of the main predictors of long-term RD, and therefore its correct detection is essen-tial7,22,26. The presence of end-renal stage disease at the time of HT should make us consider the possibility of a simultaneous kidney transplant. Recently, a U.S. registry of 263 simultaneous heart-kidney transplants has been published. Most notable among its results was the good outcome of these patients com-pared to patients with RD requiring dialysis, with a much lower benefit in those with end-renal stage disease not requiring dialysis51.

Regarding intraoperative and postoper-ative clinical situations, it is necessary to ensure correct volume management, attempting to avoid any situation that generates hypotension and promotes the development of RD. Recently, publications have appeared that suggest that the use of two new molecules (dopexamine and fenoldopam) may be associated with better tissue perfusion in the critical intra- and post-operative period than the use of classic va-sopressor drugs. Fenoldopam is a selective dopamine-1 receptor agonist, which would produce a vascular vasodilatory effect that would improve renal blood flow52. Dopexamine is another new dopamine receptor agonist that has been shown to increase blood flow in various organs53. However, these molecules require studies evaluating clinical endpoints and demonstrating their efficacy over classic vasopressor drugs.

After the surgical period, efforts should be focused on strict control of all factors that could promote medium/long-term RD, taking to account that the course of RD in the first year is crucial5. Therefore, arterial hypertension, dyslipidemia, diabetes, etc. should be con-trolled54,55.

Regarding the management of immuno-suppression, once signs of RD are detected, the introduction of mTOR inhibitors either to reduce or to replace the calcineurin inhibitor is indicated37. One of the lessons learned from kidney transplantation, which has been extrapo-lated from the rest of solid organs, is that conversion to the mTOR inhibitor should be done as early as possible because, once nephropathy is established, the patient will not benefit from the conversion56-58. In fact, some groups recommend performing a renal biopsy prior to conversion to verify the re-versibility of RD. It is also recommendable to assess proteinuria before conversion because, if significant, the change may deteriorate renal function even more. It is generally recommended to reduce the dose of the calcineurin inhibitor by half and to start everolimus at a dose of 0.75 mg/12 hours, and then to gradually reduce the calcineurin inhibitor until its complete withdrawal as soon as therapeutic levels of everolimus are reached59.

As with any non-transplanted patient, a HT patient who develops end-stage renal disease should be prepared for dialysis accord-ing to the K/DOQI guidelines43. Several studies have shown that mortality of these HT patients after a kidney transplant is similar to that of patients only having a kidney transplant, and with greater survival at five years than those who remain on the waiting list4,13.

Conclusions

Renal dysfunction following HT is a common complication with great impact on patient survival. Renal function suffers a rapid deterioration in the first year, followed by a slow but steady decline thereafter. There are numerous techniques to detect this RD that have surpassed the use of plasma creatinine. Although the etiology of RD is usually attributed to calcineurin inhibitors, there are a wide range of factors that contribute to its development.


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Several of these factors are correctable and should be intervened on, among which the most important are careful perioperative management, prevention of viral infections, and conversion to an mTOR inhibitor in early stages. In advanced stages, kidney transplant should be considered as an alternative to dialysis.

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International Society for Heart and Lung Transplantation: twenty-fourth official adult heart transplant report-2007. J Heart Lung Transplant. 2007;26:769-81.

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3. Crespo M, Delgado J, Paniagua MJ, et al. Prevalence and severity of renal dysfunction among 1059 heart transplant patients according to criteria based on serum creatinine and estimated glomerular filtration rate: A Cross-Sectional Study. J Heart Lung Transplant. 2009;28:S264. *Multicenter study conducted in a large number of transplant patients showing the prevalence of renal dysfunction in Spanish heart trans-plant patients.

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5. Hamour I, Omar F, Lyster H, Palmer A, Banner NR. Chronic kidney disease after heart transplantation. Nephrol Dial Transplant. 2009;24:1655-62.

6. Garrido IP, Crespo-Leiro MG, Paniagua MJ, et al. Independent predictors of renal dysfunction after heart transplantation in patients with normal pretransplant renal function. J Heart Lung Transplant. 2005;24:1226-30.

7. Al Aly Z, Abbas S, Moore E, Diallo O, Hauptman PJ, Bastani B. The natural history of renal function following orthotopic heart transplant. Clin Transplant. 2008;19:683-9.

8. Arora S, Andreassen A, Simonsen S, et al. Prognostic importance of renal function 1 year after heart transplanta-tion for all-cause and cardiac mortality and development of allograft vasculopathy. Transplantation. 2007;84:149-54. **Well-designed study showing the variables predicting re-nal dysfunction in heart transplant patients.

9. Hendway A, Pouteil-Noble C, Villar E, et al. Chronic renal failure and end-stage renal disease are associated with a high rate of mortality after heart transplantation. Transplant Proc. 2005;37:1352-4.

10. Cipullo R, Finger MA, Ponce F, et al. Renal failure as a de-terminant of mortality after cardiac transplantation. Trans-plant Proc. 2004;36:989-90.

11. Almenar L. Predictors of mortality following heart transplan-tation: Spanish Registry of Heart Transplantation 1984-2003. Transplant Proc. 2005;37:4006-10.

12. Villar E, Boissonnat P, Sebbag L, et al. Poor prognosis of heart transplant patients with end-stage renal failure. Neph-rol Dial Transplant. 2007;22:1383-9.

13. Alam A, Badovinac K, Ivis F, Trpeski L, Cantarovich M. The outcome of heart transplant recipients following the develop-ment of end-stage renal disease: analysis of the Canadian Organ Replacement Register (CORR). Am J Transplant. 2007;7:461-5.

14. Go AS, Chertow GM, Fan D, McCulloch CE, Hsu CY. Chronic kidney disease and the risks of death, cardiovascular events, and hospitalization. N Engl J Med. 2004;351:1296-305.

15. Ojo A. Renal Disease in recipients of nonrenal solid organ transplantation. Semin Nephrol. 2007;27:498-507. **Descrip-tive analysis of the course of renal function in solid organ transplant recipients.

16. Cantarovich M, Hirsh A, Alam A, et al. The clinical impact of an early decline in kidney function in patients following heart transplantation. Am J Transplant. 2009;9:348-54.

17. Morard I, Mentha G, Spahr L, et al. Long-term renal function after liver transplantation is related to CNI blood levels. Clin Transplant. 2005;20:96-101.

18. Dische FE, Neuberger J, Keating J, Parsons V, Caine RY, Williams R. Kidney pathology in liver allograft recipients after long-term treatment with cyclosporine A. Lab Invest. 1988;58:395-402.

19. Rábago G, Manito N, Palomo J, et al. Improvement of chronic renal failure after introduction of mycophenolate mofetil and reduction of cyclosporine dose. J Heart Lung Transplant. 2001;20:193.

20. Miller LW, Pennington DG, McBride LR. Long-term effects of cyclosporine in cardiac transplantation. Transplant Proc. 1990;22:15-20.

21. Myers BD, Newton L, Boshokos C, et al. Chronic injury of human renal microvessels with low-dose cyclosporine therapy. Transplantation. 1988;46:694-703.

22. Stratta P, Canavese C, Quaglia M, et al. Posttransplantation chronic renal damage in nonrenal transplant Recipients. Kidney Int. 2005;68:1453-63.

23. Russo MJ, Chen JM, Hong KN, et al. Survival after heart transplantation is not diminished among recipients with un-complicated diabetes mellitus: an analysis of the United Network of Organ Sharing database. Circulation. 2006; 114:2280-7.

24. Sánchez-Lázaro IJ, Almenar Bonet L, Martínez-Dolz L, et al. Effect of hypertension, diabetes and smoking on development of renal dysfunction after heart transplantation. Transplant Proc. 2008;40:2049-50.

25. Baid S, Cosimi AS, Tokoff-Rubin N, Colvin RB, Williams WW, Pascual M. Renal disease associated with hepatitis C infec-tion after kidney and liver transplantation. Transplantation. 2000;70:255-61.

26. Wilkinson AH, Cohen DJ. Renal failure in the recipients of nonrenal solid organ transplants. J Am Soc Nephrol. 1999;10:1136-44.

27. Bloom RD, Doyle AM. Kidney disease after heart and lung transplantation. Am J Transplant. 2006;6:671-9.

28. Zietse R, Balk AH, vd Dorpel M, Meeter K, Bos E, Weimar W. Time course of the decline in renal function in cy-closporine-treated heart transplant recipients. Am J Nephrol. 1994;14:1-5.

29. Fried LF, Orchard TJ, Kasiske BL. Effect of lipid reduction on the progression of renal disease: A meta-analysis. Kidney Int. 2001;59:260-9.

30. Ishani A, Erturk S, Hertz MI, Matas AJ, Savik K, Rosenber ME. Predictors of renal function following lung or heart-lung transplantation. Kidney Int. 2002;61:2228-34.

31. Rosenberg PB, Vriesendorp AD, Drazner MH, et al. Induc-tion therapy with basiliximab allows delayed initiation of cyclosporine and preserves renal function after cardiac transplantation. J Heart Lung Transplant. 2005;24:1327-31.

32. Anselm A, Cantarovich M, Davies R, Grenon J, Haddad H. Prolonged basiliximab use as an alternative to calcineurin inhibition to allow renal recovery late after heart transplanta-tion. J Heart Lung Transplant. 2008;27:1043-5.

33. Cheung CY, Liu YL, Wong KM, et al. Can daclizumab reduce acute rejection and improve long-term renal function in tacrolimus-based primary renal transplant recipients. Neph-rology (Carlton). 2008;14:251-5.

34. Angermann C, Stork S, Costard-Jackle A, Dengler T, Siebert U, Tenderich G. Reduction of cyclosporine after introduction of mycophenolate mofetil improves chronic renal dysfunc-tion in heart transplant recipients, the IMPROVED multi-centre study. Eur Heart J. 2004;25:1626-34.

35. Kobashigawa J, Miller L, Renlund D, et al. A randomized active-controlled trial of mycophenolate mofetil in heart transplant recipients. Transplantation. 1998;66:507-15.

36. Ekberg H, Tedesco-Silva H, Demirbas A, et al. Reduced exposure to calcineurin inhibitors in renal transplantation. N Engl J Med. 2007;357:2562-75.

37. Moro López JA, Almenar L, Martínez-Dolz L, et al. Pro-gression of renal dysfunction in cardiac transplantation after the introduction of everolimus in the immunosuppres-sive regime. Transplantation. 2009;87:538-41. *Descriptive


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multivariate study of the variables associated with improve-ment in renal function after heart transplantation.

38. Levey AS. Measurement of renal function in chronic renal disease. Kidney Int. 1990;38:167-84.

39. Cockcroft DW, Gault MH. Prediction of creatinine clearance from serum creatinine. Nephron. 1976;16:31-41.

40. Levey AS, Bosch JP, Lewis JB, Greene T, Rogers N, Roth D. A more accurate method to estimate glomerular filtration rate from serum creatinine: a new prediction equation. Modification of Diet in Renal Disease Study Group. Ann Intern Med. 1999;130:461-70.

41. K/DOQI clinical practice guidelines for chronic kidney disease: evaluation, classification, and stratification. Am J Kidney Dis. 2002;39:S1-266.

42. White C, Akbari A, Hussain N. Estimating glomerular filtration rate in kidney transplantation: a comparison between serum creatinine and cystatin C-based methods. J Am Soc Nephrol. 2005;6:3763-70.

43. Madero M, Sarnak MJ, Stevens LA. Serum cystatin C as a marker of glomerular filtration rate. Curr Opin Nephrol Hypertens. 2006;15:610-6.

44. Rule AD, Bergstralh EJ, Slezak, Bergert J, Larson TS. Glom-erular filtration rate estimated by cystatin C among different clinical presentations. Kidney Int. 2006;69:399-405.

45. Gaspari F, Perico N, Remuzzi G. Measurement of glomerular filtration rate. Kidney Int Suppl. 1997;63:S151-4.

46. Perrone RD, Steinman TI, Beck GJ, et al. Utility of radioiso-topic filtration markers in chronic renal insufficiency: simul-taneous comparison of 125I-iothalamate, 169-Yb-DTPA, 99mTc-DTPA, and inulin. The Modification of Diet in Renal Disease Study. Am J Kidney Dis. 1990;16:224-35.

47. Blaufox MD, Aurell M, Bubeck B, et al. Report of the Radio-nuclides in Nephrology Committee on renal clearance. J Nucl Med. 1996;37:1883-90.

48. Wilson DM, Bergert JH, Lasrson TS, Liedtke RR. GFR de-termined by non-radiolabeled iothalamate using capillary electrophoresis. Am J Kidney Dis. 1997,30:646-52.

49. Ibis A, Akgül A, Ozdemir N, et al. Posttransplant proteinuria is associated with higher risk of cardiovascular disease and

graft failure in renal transplant patients. Transplant Proc. 2009;4:1604-8.

50. Wadei HM, Geiger SJ, Cortese C, et al. Kidney allocation to liver transplant candidates with renal failure of undetermined etiology: role of percutaneous renal biopsy. Am J Transplant. 2008;8:2618-26.

51. Gill J, Shah T, Hristea I, et al. Outcomes of simultaneous heart-kidney transplant in the US: a retrospective analysis using OPTN/UNOS data. Am J Transplant. 2009;9:844-52.

52. Fontana I, Germi MR, Beatini M, et al. Dopamine “renal dose” versus fenoldopam mesylate to prevent ischemia-reperfusion injury in renal transplantation. Transplant Proc. 2005;37:2474-5.

53. Maynard ND, Bihari DJ, Dalton RN, Smithies MN, Mason RC. Increasing splanchnic blood flow in the critically ill. Chest. 1995;108:1648-54.

54. Garcia V. Progression factors for chronic kidney disease. Secondary prevention. Nefrologia. 2008;3:S17-21.

55. Ahmed Z, Simon B, Choudhury D. Management of diabetes in patients with chronic kidney disease. Postgrad Med. 2009;121:52-60.

56. Uslu A, Toz H, Sen S, et al. Late conversion from calcineurin inhibitor-based to sirolimus-based immunosuppression due to chronic toxicity: a prospective study with protocol biopsy amendment. Transplant Proc. 2009;41:756-63.

57. Schena FP, Pascoe MD, Alberu J, et al. Conversion from calcineurin inhibitors to sirolimus maintenance therapy in renal allograft recipients: 24-month efficacy and safety results from the CONVERT trial. Transplantation. 2009;87:233-42.

58. De SP, Carrai P, Precisi A, et al. Conversion to everolimus monotherapy in maintenance liver transplantation: feasibil-ity, safety and impact on renal function. Transpl Int. 2009; 22:279-86.

59. Zuckermann A, Manito N, Epailly E, et al. Multidisciplinary insights on clinical guidance for the use of proliferation signal inhibitors in heart transplantation. J Heart Lung Transplant. 2008;27:141-9. **High-level review on the management of proliferation signal inhibitors in heart transplantation.

mariarosaria Campise: Anemia after Kidney and Other Solid Organ Transplantation

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Anemia after Kidney and Other Solid Organ TransplantationMariarosaria Campise

Unit of Nephrology and Dialysis, Maggiore Foundation General Hospital, Mangiagalli e Regina Elena, IRCCS, Milan, Italy

Abstract

Anemia has long been known to be a complication of end-stage renal disease, leading to cardiovascular morbidity and mortality. Restored renal function after successful kidney transplantation should be associated with the complete correction of anemia. There are only few data available on the real prevalence of anemia after kidney transplantation. But, since many transplanted patients have some degree of renal impairment, it can be assumed that they may also experience anemia as a complication. Accordingly, some recent studies have reported anemia in about one-third of transplanted patients, regardless of the length of the follow-up. Kidney function has been identified as the main determinant, but different transplant-associated factors may contribute to the development of anemia after kidney transplantation. More recently, anemia has emerged as a major problem also among recipients of non-renal solid organ transplantation. The event is mainly associated with the development of chronic kidney disease. Beside erythropoietin deficiency, immunotherapies as well as patient comorbidities contribute to anemia development. The incidence is 28, 50, and 65% among liver, heart, and lung transplant recipients, respectively.Erythropoietin therapy is not contraindicated in solid organ transplantation, although clear information about the correct hemoglobin target is not available yet.Correction of anemia is mandatory in order to reduce this threatening cardiovascular risk factor. (Trends in Transplant. 2009;3:137-45)

Corresponding author: Mariarosaria Campise, [email protected]

Key words

Anemia. Solid organ transplantation. Erythropoietin.


Correspondence to:mariarosaria Campise

U.O di Nefrologia e Dialisi – Pad. Croff

Fondazione Ospedale maggiore Policlinico

Via della Commenda, 16

20122 milano, Italia



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Kidney transplantation

Prevalence of posttransplant anemia

It is difficult to assess the exact preva-lence of posttransplant anemia (PTA) as it is strictly dependent on the definition used.

In 1964 the World Health Organization (WHO)1 set an official definition of anemia as a hemoglobin level less than 13 g/dl in men and less than 12 g/dl in women, regardless of age and menopausal status. For the KDOQI2 and the United Kingdom Renal Association3, men and postmenopausal women are anemic if their hemoglobin levels are less than 12 g/dl, while for a menstruating woman the lower limit is a hemoglobin level lower than 11 g/dl. Finally, for the Revised European Best practice Guidelines4, anemia is defined if the hemoglo-bin level is two standard deviations less than the population mean.

With this wide variation of definition, it is no surprise that the reported incidences are so different. Furthermore, since many of the epidemiologic studies are cross-sectional or retrospective, the vintage of the transplant has to be taken into consideration.

One of the most important papers at-tempting to quantify the prevalence of PTA is a European cross-sectional survey involving 4,263 transplanted patients in 16 countries5. Anemia, defined according to the WHO crite-ria, was reported with a prevalence of 38.6%. Although 8.5% of patients were severely ane-mic, treatment was given only to 17.8%.

In other studies using different thresh-olds and times of measurement, anemia after transplantation ranged between 20 and near-ly 40%, being very common especially among African American patients6, and pediatric pa-tients7. In this last group of patients, anemia

has been observed at even higher rates: up to 60-83%.

Anemia develops earlier, more frequently, and more severely in patients with diabetic kidney disease8.

Causes of posttransplant anemia

There are many potential causes of PTA9.

A strong association has been demon-strated between hemoglobin level and poor graft function10,11, but additional transplant-associated factors also contribute to anemia development. Among them: rejection epi-sodes determining an increased inflammatory response, downregulated genes involved in erythropoiesis12, bone marrow suppression either drug-related13-15 or infection-related16, female sex, folate and vitamin B12 deficiency, malignancy, erythropoietin (EPO) resistance, and absolute or functional iron deficiency due to uremia or chronic inflammation are very common17. Low ferritin (< 100 ng/ml) has been detected in 50% of transplanted anemic patients with chronic kidney disease stage 3-5, but not in stage 118. It has to be said that in many cases anemia is multifactorial and there is a continuous overlap of different con-tributing factors.

After kidney transplantation, there is an immediate increase in EPO production19. This is not associated to an increased erythropoi-esis, and precedes graft recovery. After this initial peak there is a smaller but long-lasting increase in EPO production, associated with an improvement in graft function and erythro-poiesis. Erythropoietin production returns to normal levels after a hematocrit of 32% is reached20. Naive EPO production increases in anemic patients in comparison with non-ane-mic after transplantation21.


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Renal function

Almost every study considering the as-sociation between renal function and the pres-ence of anemia after kidney transplantation have found one. The worse the graft function, the worse the anemia is.

It can be assumed that after the early posttransplant period, restoration of almost normal graft function should completely cor-rect anemia. But, when the overall prevalence of anemia among kidney transplant recipients is compared to that observed in the general population with the same degree of renal im-pairment, the difference is almost 10-fold higher in kidney transplanted patients. There-fore, factors other than creatinine clearance contribute to the degree of anemia observed after transplantation22.

Surprisingly, also in presence of normal kidney function, EPO deficiency and relative resistance can be causes of persistent ane-mia23. Even without a significant decline in renal excretory function, delayed graft function, acute rejection, or chronic rejection, it has been hypothesized that the possible long-term toxicity of calcineurin inhibitors may cause di-minished EPO production24,25, thus sustaining the incomplete anemia correction.

The application of the chronic kidney disease (CKD) classification to kidney trans-plant recipients has been recently adopted as a strategy to improve the long-term outcome of these patients. Several series have shown that the estimated glomerular filtration rate (GFR) of a well-functioning transplanted kidney falls into the grade 2-3 of the CKD classifica-tion18,26-28 and this is inevitably associated to a number of comorbid conditions including anemia. Reduced renal function and meta-bolic acidosis11 seems to play an important role in anemia of the long term. Very often the suboptimal correction of this complication, to-gether with other comorbid conditions, causes

a dramatically reduced patient survival after graft failure29.

Impact of anemia on patient and graft survival

A recent paper tried to determine the impact of one-year PTA upon long-term patient and graft survival. In a cohort of 339 patients included in the study, 31.8% were anemic according to the WHO criteria. Independent predictors for one-year anemia were donor age and serum creatinine at six months. After a follow-up of 69.4 ± 17.4 months posttrans-plantation, a significant number of patients in the anemia group died (6.9 vs. 1.73%; p = 0.04) and a significant number of patients in the same group lost the graft (11.1 vs. 3%; p = 0.004). These results show that persisting anemia af-ter transplantation is harmful in the long term for both patient and graft survival30.

Lower hemoglobin levels were also as-sociated with graft loss on multivariate analysis of data prospectively collected as part of the pharmacovigilance Long-Term Efficacy and Safety Surveillance project (LOTESS) of No-vartis. This open, observational, cohort study included patients from 64 centers in the UK recruited between 1995 and 1998 and followed prospectively for up to seven years. The database is limited to patients treated with microemulsion cyclosporine. In this study, on univariate but not at adjusted analysis, lower hemoglobin and hemoglobin variability were associated with mortality and with mortality and graft loss, respectively. The authors sug-gest that full correction of anemia to improve mortality is not justified in renal transplant re-cipients and that further study is mandatory to assess the effect of hemoglobin correction on delaying graft failure31.

The death rate has been demonstrated to increase in anemic patients in previous studies32. The PTA cohort of patients showed


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inferior patient survival and a higher propor-tion of cardiovascular death (6.3 vs. 2.2%; p = 0.017) in comparison with the non-PTA cohort. Twelve-months PTA (HR: 3.0; 95% CI: 1.3-6.7; p = 0.009), together with 12-months creatinine, age at transplantation and hepati-tis virus C positivity, were associated with mortality. Finally, in a prospective study of 938 transplanted patients followed at a single centre and recently published20, the hypoth-esis was tested of the association between anemia and mortality and graft failure defined as return to dialysis. During a four-year follow-up, both mortality and graft failure rate were significantly higher in patients with hemoglo-bin levels below 11 g/dl. Mortality was 18 vs. 10% for anemic patients (p < 0.001) and graft failure was 17 vs. 6% (p < 0.001) in compari-son to non-anemic patients. At multivariate Cox proportional analysis, the presence of anemia significantly predicted mortality (HR: 1.690; 95% CI: 1.115-2.560) and graft failure (HR: 2.465; 95% CI: 1.485-4.090) after adjust-ment for several co-variables such as age, gender, pretransplant time on dialysis, and comorbidities including diabetes. Furthermore, each 1 g/dl decrement in serum hemoglobin level increased the odds of graft failure by 1.9% during the follow-up.

Liver transplantation

The prevalence of anemia in cirrhotic patients is due to various reasons.

The first is the presence of expanded plasma volume and portal hypertension33,34. Patients with alcoholic cirrhosis have low fo-late levels when compared to nonalcoholic (35 vs. 9%). Other causes include the re-duced red blood cell survival35; hemolysis due to enlarged spleen33, renal insufficien-cy36 and finally the ability to secrete erythro-poietin in response to anemia is often defec-tive in many patients with end-stage liver disease37.

After orthotopic liver transplantation (OLT), anemia ranges between 4.3 and 28.2% depending on the definition used. In prospective trials evaluating different immunosuppressive regimens, the incidence of anemia ranged between 1 and 53%38.

In a recent study by Guitard, et al.35, the authors evaluated the prevalence/incidence and the risk factors for anemia at six months and one year after OLT in 97 consecutive trans-plants in 88 patients. Anemia, defined accord-ing to the WHO criteria, was present in 64.5, 50, and 47.8% of patients before and at month 6 and month 12, respectively, after OLT. But in the same study, considering the hemoglobin cut off for anemia below 11 g/dl, a total 41.8% of recipients were anemic before transplanta-tion, with anemia decreasing to 13% at month 12 and being treated in only 33 and 30.3% of patients at month 6 and 12, respectively. The median weekly dosage of darbepoetin was 60 and 30 µg at the considered time intervals, with a corresponding epoetin dose of 5,000 and 20,000 U, respectively. Iron deficiency was uncommon, affecting only 14% of patients be-fore transplant, and 10.5 and 8.3% at month 6 and 12, respectively, after OLT.

At multivariate analysis, mean corpuscu-lar volume (< 85) at day 7, daily steroid dosage (< 0.3 mg/kg), serum creatinine (>130 µmol/l) and Hb level (< 11 g/dl) at month 1 were in-dependent predictive factors for anemia at month 6. Daily steroid dosage (< 0.3 mg/kg), hematocrit (< 33%), red blood cell count at month 6 (< 3.75.000 mmc), daily dosage of cyclosporine at month 1 or tacrolimus and OLT for causes other than alcohol abuse, were predictive factors for anemia at month 12.

Also among OLT patients, renal function is the strongest independent predictive factor for anemia at month 6, with an odds ratio of 13.2 (2.0-86.9; 95% CI) for creatinine at month 1 above 130 µmol/l. Plasma creatinine loses its power at month 12, when renal function seems


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not to have the same prognostic importance in comparison to other variables. This may be due to the fact that in this cohort of patients, a few are still experiencing some degree of renal impairment in the early posttransplant period, which is not present in longer follow-up.

The importance of the analysis carried out by Guitard is that this study excludes biases such as treatment with pegylated α interferon or ribavirin because none of their HCV-positive patients received these thera-pies within the first year after transplantation. In fact, it has to be considered that over 70% of HCV-positive patients receiving antiviral therapy develop anemia.

As for kidney transplantation, multiple etiologies or unrecognized causes may explain anemia also among OLT patients. But rare causes unique to transplantation include aplas-tic anemia, parvovirus B19 infection, graft-versus-host disease (GVHD), and posttrans-plant lymphoproliferative disease (PTLD).

Aplastic anemia

Aplastic anemia has been associated to hepatitis since 1955, with more than 200 cases reported in the following years. This kind of anemia has an incidence ranging between 5-33% in patients transplanted for hepatic failure secondary to “non-A, non-B, non-C hepatitis”39. In contrast, the incidence of aplastic anemia is 1-2/1,000 patients if the acute viral hepatitis does not lead to liver transplantation. The overall incidence of aplastic anemia is 7/100,000 pa-tients in large studies including all the etiolo-gies of liver failure requiring OLT40.

Parvovirus B19 infection

Liver transplant recipients, as all other solid organ transplant patients, are suscepti-ble to parvovirus B19 infection or reactivation

either from donor or blood products41. In some studies, 32% of liver transplant recipients had evidence of parvovirus B19 viremia, but the association between infection and anemia was not clear42. Similarly, only 1.8% of pediatric patients showed an association between ane-mia and parvovirus B19 infection43. At present, evidences indicate that there is no clear as-sociation between parvovirus B19 infection and anemia after OLT, even though parvovirus B19 infection still has to be considered a potential cause of posttransplant anemia.

Graft-versus-host disease

Graft-versus-host disease (GVHD) is another uncommon cause of anemia, affecting approximately 1% of liver transplant recipients and carrying a poor prognosis44. Patients typi-cally develop fever, skin rash, diarrhea, or pancytopenia within 2-6 weeks after trans-plantation. In this series, 11 out of 12 patients among 1,082 liver transplant recipients died. Risks factors for developing such a complica-tion are age above 65, recipient with a donor more than 40 years younger and a closer do-nor/recipient HLA matching. Death is usually from infectious complications, bleeding or se-vere metabolic disorders resulting from severe diarrhea and reaches 75% of cases.

Posttransplant lymphoproliferative disease

Posttransplant lymphoproliferative dis-ease (PTLD) is a complication arising typically after solid organ transplantation and often re-lated to Epstein-Barr virus (EBV) infection. It includes a group of lymphoproliferative dis-eases ranging from benign polyclonal B-cell proliferation to malignant monoclonal lymphoma-tous lesions. The first presenting symptom is autoimmune hemolytic anemia. The overall incidence is different according to the type of graft. Overall incidence among OLT recipients


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is 2-3%45. In large series, mortality is approx-imately 50%46. The mainstay of treatment is the immunosuppression drug reduction or discontinuation together with chemotherapy, and more recently, anti-CD20 monoclonal anti-bodies, radiotherapy and very seldom surgery. This high-risk population includes patients with previous antilymphocyte antibody treat-ment, EBV-seronegative patients, and pediatric patients. In children requiring antilymphocyte treatment, the risk of developing PTLD rises up to 30%.

Treatment options

Anemia treatment depends strictly on the determining cause. Nevertheless, a few considerations about recombinant EPO in liver transplantation may be useful.

Erythropoietin is reported to have a pro-tective effect on ischemia and reperfusion models also in animal liver models; the admin-istration of EPO a few minutes before isch-emia leads to a reduction in liver injury47.

Furthermore, since cyclosporine inhibits EPO production in experimental models, some authors investigated whether EPO production was impaired in liver transplant patients re-ceiving treatment with calcineurin inhibitors: cyclosporine or tacrolimus. Using multiple lin-ear regression models, the polynomial rela-tionship between hematocrit and serum EPO values was similar to the control group in pa-tients treated with tacrolimus, whereas EPO production was significantly reduced in patients receiving cyclosporine-based immunosup-pression. Hematocrit and the type of calcineurin inhibitor were the only parameters indepen-dently related to EPO levels48.

These results have important conse-quences, especially in the treatment of OLT patients needing antiviral therapy with ribavirin. In fact, a high percentage of these patients

withdraw from treatment because of symp-tomatic anemia49. In conclusion, recombinant human erythropoietin (rHuEPO) can be effec-tively administered also among OLT recipi-ents, but further clinical study will be neces-sary to evaluate the full therapeutic properties, the risk, if any, and the optimal target level of hemoglobin.

Heart transplantation

Reduced hemoglobin levels after heart transplantation is a common finding50.

Potential causes of anemia in heart transplantation are common to other solid organ transplantation: iron or vitamin B12 deficiency, folate deficiency, perioperative blood loss, he-modilution, malnutrition, bone marrow sup-pression caused by inflammation, immuno-suppressive drugs, and renal impairment. A peculiar clinical situation, though, distinguish-es patients undergoing heart transplantation in comparison to other solid organ recipients. The interaction between chronic heart failure, renal failure, and anemia forms a vicious cycle named the cardio-renal anemia syndrome51,52. The interaction between these three condi-tions causes deterioration of the cardiac and renal function and increases anemia; each of the three can cause or be caused by the other so that virtually any patient with heart failure eligible for heart transplantation is anemic.

Anemia and low hemoglobin levels are both known to be risk factors for survival in several cardiovascular disorders such as myocardial infarction and heart failure53,54.

Among heart transplant recipients, ane-mia is found to have a prevalence of about 70%55 and up to 91.6% if standard definition is used56. A very similar prevalence of anemia has been reported also for pediatric recipients57. In heart transplant recipients, there is a sig-nificant inverse correlation between creatinine


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and creatinine clearance and hemoglobin levels (p = 0.01) and also a strong trend for inverse correlation between creatinine and EPO levels58. Contrary to other cardiovascular disorders, low hemoglobin levels after heart transplantation do not represent an indepen-dent risk factor for reduced survival, but the demonstrated correlation is primarily caused by concomitant functional renal impairment59. Low hemoglobin levels were not associated with low leukocyte or thrombocyte count, in-dicating that there was not hemodilution as concomitant cause, nor did they represent a consequence of overall bone marrow suppres-sion caused by antiproliferative medication.

Low EPO levels have also been detect-ed in most heart transplant recipients58. When administered, EPO therapy resulted in in-creased hemoglobin levels and improvement of quality of life in 75% of patients, allowing effective anemia management.

Lung transplantation

There is a paucity of information regard-ing chronic anemia after lung transplantation, particularly as it relates to chronic renal insuf-ficiency. However, the reported prevalence is about 65%60 with 31% of heart and lung trans-plant recipients showing significant anemia with hemoglobin less than 10 g/dl in a single-centre experience61. Anemia is normochromic and in the majority of cases normocytic with normal reticulocyte count. Iron deficiency with a transferrin saturation below 20% was found in 35% of patients. Erythropoietin levels were significantly decreased in anemic lung trans-plant recipients, compared to non-transplant-ed iron-deficient patients. Non-anemic lung transplant recipients showed significantly low-er EPO levels as compared with normal con-trols. No variables including plasma creatinine appeared to be a prognostic factor. Only female sex showed a trend toward higher EPO levels60.

The demonstration of low EPO levels offers a rationale for treatment of chronic ane-mia with recombinant human erythropoietin (rHuEPO) also for lung transplant recipients. In a letter to the Editor published in 1994, End, et al. reported their first experience with rHuEPO therapy after lung transplantation62. They treated only four patients with a mean initial hematocrit level of 26%. Therapy was started 10-50 weeks after transplantation. Hematologic parameters increased significantly with mean hemoglobin after treatment, ranging between 12 and 13.5 g/dl. No side effect was experi-enced. Because of different individual respons-es, the duration of treatment was 1-15 weeks (median 5). In three patients, after anemia correction, treatment was stopped due to sus-tained stable hemoglobin levels above 10 g/dl. Mean single rHuEPO dose was 58 IU/kg.

The authors recommend rHuEPO treat-ment in lung transplanted patients with chron-ic anemia, either to prevent the potential risk of transfusion-transmitted viral infection, or to save blood products.

Conclusions

Anemia after kidney and solid organ transplantation is mainly but not only related to renal function. The best prevention should be the use of all the available measures aimed at protecting and maintaining a good renal function also among kidney transplant recipi-ents. Several other equally important factors, some of which are unique to the transplant environment, can contribute to the appearance of this complication. Prompt identification and, where possible, successful correction, leads to anemia resolution.

Nevertheless, if PTA occurs it has to be treated immediately regardless of the type of transplanted organ, particularly in symptom-atic patients or in patients with hemoglobin levels below 10 g/dl.


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Still we are lacking large, well de-signed, prospective studies that can answer questions about response to treatment, he-moglobin target, risks if any, costs, and choice among the different erythropoiesis stimulating agents .

At present, even though many of the potential benefits of anemia correction have been demonstrated, the available literature still reports a surprisingly low rate of correction of this complication that affects half of the whole transplanted population and is a threat to patient and graft survival.

References 1. WHO: Nutritional Anemia. World Health Organization Techni-

cal report Series No. 405. Geneva, Switzerland, World health organization, 1968.

2. National kidney Foundation: K/DOQI Clinical Practice Guide-lines for Anemia of Chronic Kidney Disease. Am J Kidney Dis. 2001;37:S182-238.

3. The Renal Association: Treatment of Adults and Children With Renal Failure. Standards and Audit Measures (ed 3) 2002. London, UK, Royal College of Physicians of London and the Renal Association.

4. Cameron JS. European best practice guidelines for the man-agement of anemia in patients with chronic renal failure. Nephrol Dial Transplant. 1999;14:61-65. *Indications for starting treatment with epoetin, recommended minimum tar-get hemoglobin concentrations, epoetin dosage and route of administration, assessing and optimizing iron stores, causes and management of epoetin resistance, and possi-ble adverse effects of epoetin treatment.

5. Vanrenterghem Y, Ponticelli C, Morales JM et al. Prevalence and management of anemia in renal transplant recipients: A European survey. Am J Transplant. 2003;3:835-45. **The TRansplant European Survey on Anemia Management (TRESAM) documents the prevalence and management of anemia in kidney transplant recipients. First study collecting data from 72 transplant centers in 16 countries, involving 4,263 patients who had received transplants 6 months, 1, 3 or 5 years earlier.

6. Shibagaki Y, Shetty A. Anemia is common after kidney trans-plantation, especially among African American. Nephrol Dial Transplant. 2004;19:2368-73. *African American race as well as high serum creatinine and female gender are indepen-dent risk factors for posttransplant anemia. The importance of anemia as a risk factor in African American patients after renal transplantation is mentioned for the first time.

7. Yorgin PD, Belson A, Sanchez J, et al. Unexpected high prevalence of posttransplant anemia in pediatric and young adult renal transplant recipients. Am J Kidney Dis. 2002;40:1306-18. **This is an important retrospective study on 162 pediatric renal transplant recipients, the au-thors sought to determine the prevalence, severity, and the predictive factors of PTA. Anemia was present in 67% of transplant recipients at transplantation and increased to 84.3% in the first month posttransplant remaining 82.2% at month 60.

8. Bosman DR, Winkler AS, Marsden JT, Macdougall IC, Wat-kins PJ. Anemia with erythropoietin deficiency occurs early in diabetic nephropathy. Diabetes Care. 2001;24:495-9.

9. Moore LW, Smith SO, Winsett RP, et al. Factors affecting erythropoietin production and correction of anemia in kidney transplant recipients. Clin Transplant. 1994;8:358-64.

10. Mix TC, Kazmi W, Khan S, et al. Anemia: a continuing prob-lem following kidney transplantation. Am J Transplant. 2003;3:1426-33. *Retrospective cohort study, single-centre experience of the prevalence of and factors associated with anemia among 240 kidney transplanted patients.

11. Yorgin PD, Scandling JD, Belson A, Sanchez J, Alexander SR, Andreoni KA. Late posttransplant anemia in adult renal transplant recipients: A under-recognized problem? Am J Transplant. 2002;2:429-35.

12. Chua MS, Barry C, Chen X, Salvatierra O, Sarwal MM. Mo-lecular profiling of anemia in acute renal allograft rejection using DNA microarrays. Am J Transplant. 2003;3:17-22. **The AA analyzed the gene expression profiles of periph-eral blood lymphocytes from four pediatric renal allograft recipients with acute rejection and concurrent anemia. In these anemic rejecting patients, an ‘erythropoiesis cluster’ of 11 downregulated genes was identified.

13. Gossmann J, Thurmann B, Bachmann T, et al. Mechanism of angiotensin converting enzyme inhibitor-related anemia in renal transplant recipients. Kidney Int. 1996;50:973-8.

14. Ersoy A, Kahvecioglu S, Ersoy C, Cift A, Dilek K. Anemia due to losartan in hypertensive renal transplant recipients without posttransplant erythrocytosis. Transplant Proc. 2005;37:2148-50.

15. Augustin JJ, Knauss TC, Schulak JA, et al. Comparative effects of sirolimus and mycophenolate mofetil on erythro-poiesis in kidney transplant patients. Transplantation. 2004;4:2001-4.

16. Egbuna O, Zand MS, Arbini A, Menegus M, Taylor J. A cluster of parvovirus B19 infection in renal transplant re-cipients: A prospective series and review of the literature. Am J Transplant. 2006;6:225-31.

17. Afzali B, Al-Khoury S, Shah N, Mikhail A, et al. Anemia after renal transplantation. Am J Kidney Dis. 2006;48:519-36. **Detailed review on anemia after kidney transplantation aimed at appraising the available literature on the topic and concentrating on etiopathogenesis, effects on morbidity and mortality and rationale for intervention and treatment.

18. Karthikeyan V, Karpinski J, Nair RC, Knoll G. The burden of chronic kidney disease in renal transplant recipients. Am J Transplant. 2004;4:262-9. **This study determined the prev-alence of CKD according to the stages defined in the guide-line for chronic renal failures in 459 renal transplant recipi-ents. The classification of renal transplant patients by CKD stage may help clinicians identify patients at increased risk and target appropriate therapy to improve outcomes.

19. Sun CH, Ward HJ, Paul WL, et al. Serum erythropoietin levels after renal transplantation. New Engl J Med. 1989; 321:151-7.

20. Molnar MZ, Czira M, Ambris C, et al. Anemia is associated with mortality in kidney-transplanted patients: A prospective cohort study. Am J Transplant. 2007;7:818-24.

21. Sinnamon KT, Courtney AE, Maxwell AP, et al. Level of renal function and serum erythropoietin levels independently pre-dict anemia post renal transplantation. Nephrol Dial Trans-plant. 2007;22:1969-73.

22. Chadban SJ, Baines L, Polkinghorne K, et al. Anemia after kidney transplantation is not completely explained by re-duced kidney function. Am J Kidney Dis. 2007;49:301-9.

23. Nampoory MR, Johny KV, alHilali N, Seshadri MS, Kanagas-abhapathy AS. Erythropoietin deficiency and relative resistance cause anemia in post-kidney transplant recipients with normal kidney function. Nephrol Dial Transplant. 1996;11:177-81.

24. Besarab A, Caro J, Jarrell BE, Franos G, Erslev AJ. Dynam-ics of erythropoiesis following renal transplantation. Kidney Int. 1987;32:526-36.

25. Jensen JD, Hansen HE, Pedersen EB. Increased serum erythropoietin level during azathioprine treatment in renal transplant recipients. Nephron. 1994;67:297-301.

26. Djamali A, Kendziorski C, Brazy PC, Becker BN. Disease progression and outcomes in chronic kidney disease and renal transplantation. Kidney Int. 2003;64:1800-7.

27. Marcén R, Pascual J, Tenorio M, et al. Chronic kidney dis-ease in renal transplant recipients. Transplant Proc. 2005;37:3718-20.

28. Fernandez-Fresnedo G, de Francisco A, Ruiz JC, et al. Relevance of chronic kidney disease classification (K/DOQI) in renal transplant patients. Transplant Proc. 2006;38:2402-3.


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29. Arias M, Escallada R, de Francisco AL, et al. Return to di-alysis after renal transplantation. Which would be the best way? Kidney Int. 2002;80:85-8.

30. Kamar N, Rostaing L. Negative impact of one-year anemia on long-term patient and graft survival in kidney transplant patients receiving calcineurin inhibitors and mycophenolate mofetil. Transplantation. 2008;85:1120-4. **The aim of this study was to assess the incidence of PTA 1 year after trans-plantation in patients treated with CNIs and MMF, and to determine the impact of 1-year PTA upon long-term patient and graft survival: the occurrence of PTA at 1 year is harm-ful, in the long term, to patient survival.

31. Moore J, He X, Cockwell P, Little MA, Johnston A, Borrows R. The impact of hemoglobin levels on patient and graft survival in renal transplant recipients. Transplantation. 2008;86:564-70.

32. Imoagene-Oyedeji AE, Rosas SE, Doyle AM, et al. Posttrans-plantation anemia at 12 months in kidney transplant recipients treated with mycophenolate mofetil: Risk factors and impli-cation for mortality. J Am Soc Nephrol. 2006;17:3240-7.

33. Kimber C, Deller DJ, Ibbotson RN, Lander H. The mechanism of anemia in chronic liver disease. Q J Med. 1965;34:33-64.

34. Lieberman FL, Ito S, Reynolds TB. Effective plasma volume in cirrhosis with ascites: evidence that a decreased value does not account for renal sodium retention, a spontaneous reduction in glomerular filtration rate (GFR), and a fall in GFR during drug-induced dieresis. J Clin Invest. 1969;48:975-81.

35. Guitard J, Ribes D, Kamar N, et al. Predictive factors for anemia six and twelve months after orthotopic liver trans-plantation. Transplantation. 2006;81:1525-31. *Anemia, de-fined according to the WHO criteria, was highly prevalent within the first year of post-OLT. Independent predictive factors were also identified.

36. Bruno CM, Neri S, Sciacca C et al. Plasma erythropoietin levels in anemic and non-anemic patients with chronic liver disease. World J Gastroenterol. 2004;10:1353-6.

37. Vasilopoulos S, Hally R, Caro J, et al. Erythropoietin re-sponse to post-liver transplantation anemia. Liver Trans-plant. 2000;6:349-55.

38. Randomized trial comparing tacrolimus (FK 506) and CsA in prevention of liver allograft rejection. European FK multi-centre liver study group. Lancet. 1994;344:423-8. **In this paper were recruited 545 liver transplant recipients from eight European centers into a randomized open trial aimed at comparing the immunosuppressive property of tacrolimus in comparison with cyclosporin.

39. Cattral MS, Langnas AN, Markins RS, et al. Aplastic anemia after liver transplantation for fulminant liver failure. Hepatol-ogy. 1994;20:813-18.

40. Goss JA, Schiller GJ, Martin P, et al. Aplastic anemia com-plicating orthotopic liver transplantation. Hepatology. 1997;26:865-9.

41. Chang FY, Singh N, Gayowski T, Marino IR. Parvovirus B19 infection in a liver transplant recipient: case report and re-view in organ transplant recipients. Clin Transplant. 1996;10:243-7.

42. Ndimbie OK, Frezza E, Jordan JA, Koch W, van Thiel DH. Parvovirus B19 in anemic liver transplant recipients. Clin Diagn Lab Immunol. 1996;3:756-60.

43. Misra S, Moore TB, Ament ME, et al. Profile of anemia in children after liver transplantation. Transplantation. 2000; 70:1459-63.

44. Smith DM, Agura E, Netto G, et al. Liver transplant-asso-ciated graft-versus-host disease. Transplantation. 2003; 75:118-26.

45. Kahan-Ponticelli. Principles and practice of renal transplan-tation. Martin Duniz Pub. 2000;15:622-8.

46. Jain A, Nalesnik M, Reyes J, et al. Posttransplant lymphop-roliferative disorders in liver transplantation a 20-year expe-rience. Ann Surg. 2002;4:429-37.

47. Sepodes B, Maio R, Pinto R, et al. Recombinant human erythropoietin protects the liver from hepatic ischemia-rep-erfusion injury in the rat. Transplant Int. 2006;19:919-26.

48. Bardet V, Pissaria AJ, Coste J, et al. Impaired erythropoietin production in liver transplant recipients: the role of calcineu-rin inhibitors. Liver Transplant. 2006;12:1649-54. *Compari-son between tacrolimus or cyclosporine-treated liver trans-plant recipients in order to demonstrate the influence of either CNI on EPO production and consequent anemia.

49. Dumortier J, Scoazec JY, Chevallier P, Boillot O. Treatment of recurrent hepatitis C after liver transplantation: a pilot study of peginterferon α-2b and ribavirin combination. J Hepatol. 2004;40:669-74.

50. Frost AE, Keller CA. Anemia and erythropoietin levels in recipients of solid organ transplant. The Multi-Organ Trans-plant Group. Transplantation. 1993;53:1008-11.

51. Efstratiadis G, Konstantinou D, Chytas I, Vergoulas G. Car-dio-renal anemia syndrome. Hippokratia. 2008;12:11-16.

52. Celik T, Iyisoy A, Kursaklioglu H, Gungor M, Yuksel UC. Anemia and cardio-renal anemia syndrome: a deadly as-sociation? Int J Cardiol. 2008;128:255-6. **The cardio-renal anemia syndrome is emerging with progressively elevated significance since the interaction between chronic heart fail-ure, chronic kidney insufficiency and anemia, form a vicious cycle that causes deterioration of the cardiac and renal function and increases anemia. Anemia itself can worsen cardiac function and symptoms in patients with congestive heart failure: correction of anemia may beneficial.

53. Wu WC, Rathore SS, WangY, et al. Blood transfusion in el-derly patients with acute myocardial infarction. N Engl J Med. 2001;17:1230-6.

54. Ezekowitz JA, McAlister FA, Armstrong PW. Anemia is com-mon in heart failure and is associated with poor outcome: insight from a cohort of 12065 patients with new-onset heart failure. Circulation. 2003;107:223-5.

55. Müller HM, Horina JH, Knieppeiss D, et al. Characteristics and clinical relevance of chronic anemia in adult heart trans-plant recipients. Clin Transplant. 2001;15:343-8.

56. Braunwald E, Fauci AS, Hauser SL, et al. eds. Harrison’s principles of internal medicine [ed 15]. New York, McGraw-Hill Book Company. 2001;1118.

57. Embleton ND, O’Sullivan JJ, Hamilton JRL, Dark JH, Sum-merfield GP. High prevalence of anemia after cardiac trans-plantation in children. Transplantation. 1997;64:1590-4.

58. Gleissner CA, Klingenberg R, Staritz P, et al. Role of eryth-ropoietin in anemia after heart transplantation. Int J Cardiol. 2006;112:341-7. **This paper defines the type of anemia after heart transplantation and the effects of EPO therapy. Since anemia is associated with renal impairment, the AA suggest that erythropoietin may be a superior marker of functional renal impairment after heart transplantation.

59. Gleissner CA, Murat A, Schäfer S et al. Reduced hemoglobin after heart transplantation is no independent risk factor for survival but is associated closely with impaired renal func-tion. Transplantation. 2004;77:710-17.

60. End A, Stift A, Wieselthaler G, et al. Anemia and erythropoi-etin levels in lung transplant recipients Transplantation. 1995;60:1245-51.

61. Hunt BJ, Amin S, Halil D, Yacoub M. The prevalence, course and characteristic of chronic anemia after heart and lung transplantation. Transplantation. 1992;52:1251-6. **Old but important paper on the prevalence, course and character-istic of chronic anemia after heart and lung transplantation. A detailed study performed in 16 out of 99 patients included bone marrow aspiration. Anemia appears to be a combina-tion of anemia of chronic disease and dyshemopoiesis, both of uncertain etiology.

62. End A, Ringl H, Grimm M, et al. Chronic anemia after lung transplantation: treatment with human recombinant erythro-poietin. Transplantation. 1995;57:1142.


146

The Myth of BioequivalenceHeidi M. Schaefer and J. Harold Helderman

Department of Medicine, Division of Nephrology, Vanderbilt University Medical Center, Nashville, TN, USA


Heidi m. Schaefer

Assistant Professor of medicine

Division of Nephrology, S-3223 mCN

Vanderbilt University medical Center

21st Avenue South

Nashville, tN 37232-2372, USA


Abstract

Generic medications can lead to significant economic and health-related savings in transplant recipients who require life-long immunosuppression to maintain survival of the allograft. Despite the growing number of generic immunosuppressants, there is significant concern over the process of approval by the FDA, particularly with regards to “narrow therapeutic range”, in which demonstration of bioequivalence between generic and innovator drugs is carried out in normal, healthy volunteers. Bioequivalence between two agents in normal volunteers may not hold true among patient subpopulations that differ with regards to demographics, disease state, or the use of concomitant, potentially interfering medications. It is recommended that that the FDA considers replication of bioequivalence data by generic manufacturers of narrow therapeutic range drugs in transplant recipients. It is also recommended that certain safeguards and consistent policies be adopted to ensure that generic substitution is practiced in a responsible manner, including notification of the prescribing physician and patient when the pharmacy dispenses a narrow therapeutic range drug in a different formulation from the current medication. Therapeutic substitution should not occur unless the prescribing physician grants approval and institutes appropriate monitoring. Patients should be educated about the use of generics so that they recognize substitution and are allowed to participate in treatment decisions. (Trends in Transplant. 2009;3:146-52)

Corresponding author: Heidi M. Schaefer, [email protected]

Key words

Generic. Immunosuppression. Cyclosporine. Bioequivalence. Narrow therapeutic range.

Introduction

Transplantation is the therapy of choice for patients with end-stage organ disease.

More than two decades ago, the calcineurin inhibitor cyclosporine (CsA) was introduced, resulting in less acute rejection and improved graft survival compared with previous immu-nosuppressive regimens1. Although vital for organ survival, life-long immunosuppression is not without significant cost to the patient2. In the USA there are over 200,000 transplant recipients who require daily immunosuppres-sive therapy.

Generic medications offer patients the advantage of providing equivalent therapeutic

Heidi m. Schaefer and J. Harold Helderman: Generic Immunosuppression

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efficacy at a lower cost to the patient, health-care system, and society. Lower-cost alterna-tives may improve adherence to therapies for patients who cannot afford innovator drugs, and provide an increased duration of therapy for those patients with capped medical ben-efits3. In 2008, generic drugs accounted for more than 63% of total prescriptions filled in the USA4. Despite the widespread availability of generic alternatives, substitution of these medications remains a topic of intense de-bate, particularly in the field of transplanta-tion, in which survival of the organ, and in many cases the recipient, are at stake. At the core of the controversy is whether the current FDA standards regulating bioequivalence are restrictive enough to ensure that generic formulations of narrow therapeutic range drugs are clinically equivalent to their brand-name counterparts.

Generic approval process

According to the FDA, a generic drug is a product that compares to the innovator or reference drug product in dosage form, route of administration, strength, quality, safety, and performance characteristics. The generic drug must have the same in-tended use as the innovator product that serves as its prototype5. Unlike the approv-al process for innovator products, requiring manufacturers to include preclinical and clinical data establishing safety and efficacy of the active ingredient, the Drug Price Competition and Patent Term Restoration Act passed in 1984, more commonly known as the Hatch-Waxman Act, permitted the FDA to approve generic drugs without re-peating safety and efficacy studies6,7. This is considered to be one of the most pivotal legislative moves on behalf of the generic drug industry as it eliminated the require-ment for randomized trials to demonstrate clinical efficacy as long as bioequivalence was shown.

Bioequivalence refers to the absence of significant differences in the rate and extent to which active ingredients in phar-maceutical equivalents become available at the site of drug action in the body when administered under similar experimental conditions8. Bioequivalence studies aim to demonstrate that two pharmaceutical equivalents have similar pharmacokinetics. It is determined by evaluation of the area under the curve (AUC) and the maximum concentration of the drug (Cmax). A generic product is considered to be bioequivalent to the innovator product if the 90% confidence interval of the mean AUC and the relative mean Cmax is 80-125%. This criterion is the same standard used for testing the bioequiv-alence of branded products with reformu-lation or manufacturing changes. Bioequiv-alence studies typically enroll 24-36 healthy male adult volunteers, ages 18-50 years, in a single-dose, crossover design with the drug administered under fasting conditions. The Cmax, time to reach Cmax, and AUC are determined by taking multiple blood sam-ples from individual patients. Based on the 90% confidence interval, if drug levels vary by more than 10%, failure to reach FDA cri-teria disqualifies a drug for a bioequivalence rating8-10.

Critical-dose drugs

Despite determinations of statistical bioequivalence, there is still reluctance on the part of clinicians to substitute generic formulations for innovator drug products, particularly with regard to those having a narrow therapeutic index or “critical-dose drugs”. These drugs require careful patient monitoring and frequent dose adjustments as small changes in dose and/or blood con-centration could potentially result in clini-cally important changes in drug efficacy or safety11. Consensus conferences held in the USA and Europe12-14 raised nonequivalence


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Table 1. Critical-dose drug characteristics

Narrow therapeutic range

Requirement for blood level monitoring

Dosing based on body weight or other highly individualized dosing requirements

Serious clinical consequences of overdosing (toxicity) or underdosing (lack of effect)

Steep dose-response relationship for either efficacy or toxicity or both

Adapted from Sabatini, et al.12

concerns over generic substitution of im-munosuppressant agents, in particular cy-closporine and tacrolimus as these meet the criteria of critical-dose drugs (Table 1). The narrow therapeutic range has been well described with cyclosporine and the mea-surement of drug trough levels showing sig-nificant rates of acute rejection at low trough concentrations and toxic effects at higher concentrations15. Of note, there is significant overlap between toxic and nontoxic patients. Cyclosporine has also been noted to display significant inter- and intra-individual varia-tions in drug absorption, distribution, me-tabolism, and elimination16. In an analysis by Kahan, et al.17, it was demonstrated that those patients with significant intra-individu-al variability of cyclosporine exposure had an increase in the incidence of chronic re-jection. The renal transplant recipients who were described as variable could not be dis-criminated from the less-variable cohort based on demographic, clinical, or labora-tory characteristics, but only by serial phar-macokinetic profiling, further emphasizing the role of frequent drug monitoring of criti-cal-dose drugs17. There are also formulation-dependent bioavailability issues to consider with cyclosporine. Depending on the deliv-ery system, there can be significant differ-ences in the peak concentrations, rate of absorption, and area under the concentration curve18,19. For example, Curtiss, et al. exam-ined differences in bioavailability between

the oral solution formulation of Sandimmune® (Sandoz Pharmaceuticals) and the soft gela-tin capsule formulation in a randomized crossover study of 20 maintenance renal transplant recipients shown by screening pharmacokinetic profile to be poor absorb-ers of cyclosporine. Significant differences were noted, with an average 38% greater peak and 11% greater total exposure for the soft gelatin capsule as compared to the oral solution20.

Impact of generic formulations on clinical outcomes

As mentioned above, bioequivalence is determined from single-dose studies in small numbers of fasting, healthy, normal volunteers, often homogeneous in characteristics. It is important to note that bioequivalence does not take into account potential drug interac-tions, disease interactions, or patient vari-ables. Also, single dosing in contrast to chronic administration does not create the steady state conditions necessary for accu-rate evaluation of bioequivalence. It has been suggested that pharmacokinetics in healthy volunteers may not accurately reflect those in transplant recipients, particularly with critical-dose drugs. One must also recognize that bioequivalence alone does not demonstrate therapeutic equivalence, which is what pro-viders desire and patients expect. Hibberd,


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et al. recently compared a generic formula-tion of cyclosporine, Cysporin (Mayne Pharma Limited) to the innovator drug, Neoral® (No-vartis Pharmaceuticals) in a stable cohort of renal transplant recipients and found that al-though bioequivalent, the pharmacokinetics differed, with the rate and extension of ab-sorption of the generic product being less and slower21. This could potentially have sig-nificant clinical consequences if the patient was switched to the generic drug without the physician being aware and ordering repeated CsA monitoring.

In a single-center retrospective review of patients initiated on Neoral® vs. Gengraf® (Abbott Laboratories), it was noted that the Gengraf® patients were significantly more likely to have a biopsy proven acute rejec-tion episode during the first six months post-transplantation and also to have a second biopsy proven acute rejection episode22. It was interesting to note that the coefficient of variation of mean 12-hour CsA trough concentrations was significantly higher for Gengraf®, particularly in African American patients. These factors, in particular in-creased coefficient of variation, have been shown to be associated with increased rates of chronic rejection. Kahan, et al. examined individual pharmacokinetic parameters in 204 patients treated for up to five years and found that a greater than 20% coefficient of variation of cyclosporine bioavailability was a risk factor for the occurrence of chronic rejection23. The Collaborative Transplant Study group has demonstrated that patients who received Neoral® as compared to San-dimmune® had superior four-year graft sur-vival24.

Healthcare costs

Ultimately, the clinical outcomes of switching from innovator drug to generic, in particular with regards to cyclosporine, can

affect total healthcare costs with re-hospi-talization, management of acute rejection, and possibly graft failure with return to di-alysis and retransplantation. An economic analysis performed on the previously men-tioned study by Kahan, et al.17 found that those patients with less-variable CsA expo-sure had significantly lower healthcare costs as compared to those with more-variable CsA exposure ($48,789 vs. 60,998 over five years; p < 0.01). Most recently, we have assessed overall healthcare costs for de novo renal transplant recipients receiving branded vs. generic CsA formulations25. In a cohort of 227 recipients, total healthcare costs were 46% higher for patients receiv-ing generic vs. branded CsA. For the aver-age patient, predicted costs were $36,443 for generic CsA and $31,494 for branded CsA, representing a statistically significant difference of $4,949. The difference in cost for this particular cohort was primarily driven by cost associated with immunosuppres-sants other than CsA, suggesting that the cost saving associated with generic CsA is outweighed by the need for more immuno-suppressants to maintain the transplanted kidney.

Recommendations for drug substitution in transplantation

As the patents for Prograf® (Astellas Pharma) and CellCept® (Roche Pharmaceuti-cals) expire and generics for these innovator drugs become available, one can draw on the lessons learned from cyclosporine. As we are all aware, noncompliance is a prominent cause of graft failure, with a portion of the noncompliance attributable to the inability to afford the cost of expensive immunosuppres-sive medications on the part of the patient26. If savings resulting from the use of generic immunosuppressive medications are passed on to payers and consumers, then the use of


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generic alternatives has the ability to improve compliance and reduce out-of-pocket ex-penses.

In prescribing generics, particularly those new to the market, one must use both common sense and caution. Currently, most regulations are to ensure that generic substi-tution is practiced in a responsible manner and made and enforced at the state level11,27. Those regulations vary from state to state, which has led to inconsistency in substitution practices and may cause confusion when trying to evaluate on a broad level.

A major concern is that a prescribing provider may not be aware of a switch by the pharmacist to a generic. In such in-stances, the physician would be unaware of the possible consequences of the switch. Another concern is that the patient is not involved in the decision to switch medica-tions. Based on these issues and to ensure safety and consistency in practice, recom-mendations were set forth by several orga-nizations12-14 (Table 2). Most important is

that the physician and patient be made aware of the substitution so that appropriate follow-up and drug monitoring can take place.

The FDA has acknowledged that there may be issues in generalizing results obtained in healthy volunteers to specific subgroups of patients, particularly with critical-dose drugs. For such patients, the products might not be bioequivalent, even though these agents can be bioequivalent for most of the population. Although it would be difficult to establish bioequivalence in every potential patient subgroup, it is recommended that the FDA consider individualizing the bioequivalence testing for certain generic formulations, in particular those with a narrow therapeutic range.

Conclusions

As generic formulations for immunosup-pressant medications become more widely available, it is important for providers to have

Table 2. Recommendations for the use of generic immunosuppressant drugs

The healthcare provider should educate the patient about generic drugs and should include the patient in the decision of whether to switch drugs.

The pharmacist should inform the prescribing physician and patient whenever a prescribed immunosuppressive drug is to be switched.

Physicians should seek information about the bioequivalence data for the agents they prescribe and should be able to exercise their option to request substitution not be made if there is concern about maintenance of consistent drug regimens or about bioequivalence of generic drugs.

Patients should be taught how to identify the prescribed dosage form, and they should alert the physician if a substitution is made.

The FDA should require that the appearance of all medications be unique and easily identifiable to help patients distinguish among drug products.

Because of potential consequences arising from differences in bioavailability or intra-subject variability with different products of critical-dose drugs, physicians should consider instituting appropriate monitoring whenever a patient is switched from one formulation to another.

The healthcare team should report adverse events with innovator and generic drugs to the FDA and the drug’s manufacturer and document the information in the patient record.

Adapted from Alloway, et al.13 and Sabatini, et al.12


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a clear understanding of the approval pro-cess and how bioequivalence is determined. One must know that the pharmacokinetic pro-files of critical-dose drugs may be different among transplant patients as compared to normal, healthy volunteers. These differences may lead to unanticipated differences in clin-ical response when generics are substituted for innovator drugs in this population. As a result, certain safeguards should be adopted to prevent poor outcomes from inappropriate generic substitution. It has been recommend-ed that the FDA consider more stringent stan-dards for bioequivalence with regards to critical-dose drugs, requiring drug manufac-turers to conduct replicate studies of intra-subject variability and subject-by-formulation interactions in addition to conventional bio-availability studies. It is also suggested that the generic manufacturer show bioequivalence in target populations in which the innovator drug has shown substantial pharmacologic variation.

Obviously, the cost-related benefits with regards to generics, including potential for improved compliance, are welcome, but the provider and patient must be aware of substitutions by the pharmacy to ensure that appropriate monitoring is instituted and pa-tients are managed accordingly. Only with consistent substitution practices adopted by all parties can one ensure the safe and effec-tive use of generic drugs in the transplant population.

References 1. Danovitch GM. Choice of immunosuppressive drugs and

individualization of immunosuppressive therapy for kidney transplant patients. Transplant Proc. 1999;31:2-6S.

2. Bennett WM, Olyaei AJ. Pharmacoeconomics of immuno-suppressive agents in renal transplant recipients. Transplant Proc. 1999;31:6S.

3. Shrank WH, Hoang T, Ettner SL, et al. The implications of choice: prescribing generic or preferred pharmaceuticals improves medication adherence for chronic conditions. Arch Intern Med. 2006;166:332-7. *This study suggests that pa-tients who receive generic medications are more adherent to therapy.

4. http://www.allbusiness.com/pharmaceuticals-biotechnology/pharmaceutical/12177752-1.html [accessed September 29, 2009].

5. http://www.fda.gov/Drugs/DevelopmentApprovalProcess/HowDrugsareDevelopedandApproved/ApprovalApplica-tions/AbbreviatedNewDrugApplicationANDAGenerics/de-fault.htm [accessed September 29, 2009].

6. Ascione FJ, Kirking DM, Gaither CA, Welage LS. Historical overview of generic medication policy. J Am Pharm Assoc (Wash). 2001;41:567-77. *This article provides a nice over-view of the controversies that exist over the use of generic medications.

7. Welage LS, Kirking DM, Ascione FJ, Gaither CA. Under-standing the scientific issues embedded in the generic drug approval process. J Am Pharm Assoc (Wash). 2001; 41:856-67.

8. Nation RL, Sansom LN. Bioequivalence requirements for generic products. Pharmacol Ther. 1994;62:41-55. **This article defines bioequivalence and describes in detail the requirements for pharmacokinetic bioequivalence and the design and conduct of bioequivalence studies.

9. Benet LZ. Understanding bioequivalence testing. Transplant Proc. 1999;31:7-9S.

10. Pentikis HS, Henderson JD, Tran NL, Ludden TM. Bioequiv-alence: individual and population compartmental modeling compared to the noncompartmental approach. Pharm Res. 1996;13:1116-21.

11. Nightingale SL. From the Food and Drug Administration. JAMA. 1998;279:645.

12. Sabatini S, Ferguson RM, Helderman JH, Hull AR, Kirk-patrick BS, Barr WH. Drug substitution in transplantation: a National Kidney Foundation White Paper. Am J Kidney Dis. 1999;33:389-97. **A consensus conference report on the use of generic immunosuppression in transplant re-cipients.

13. Alloway RR, Isaacs R, Lake K, et al. Report of the American Society of Transplantation conference on immunosuppres-sive drugs and the use of generic immunosuppressants. Am J Transplant. 2003;3:1211-5. **A consensus conference re-port on the use of generic immunosuppression in transplant recipients.

14. Pollard S, Nashan B, Johnston A, et al. A pharmacokinetic and clinical review of the potential clinical impact of using different formulations of cyclosporin A. Berlin, Germany, No-vember 19, 2001. Clin Ther. 2003;25:1654-69. **A consen-sus conference report on the use of generic immunosup-pression in transplant recipients.

15. Bowers LD. Therapeutic monitoring for cyclosporine: difficul-ties in establishing a therapeutic window. Clin Biochem. 1991;24:81-7. *One of the most informative reviews of the difficulties in using cyclosporine drug monitoring.

16. Kahan BD. Individualization of cyclosporine therapy using pharmacokinetic and pharmacodynamic parameters. Trans-plantation. 1985;40:457-76.

17. Kahan BD, Welsh M, Urbauer DL, et al. Low intraindividu-al variability of cyclosporin A exposure reduces chronic rejection incidence and healthcare costs. J Am Soc Neph-rol. 2000;11:1122-31. *This study examines the intra-indi-vidual variability associated with cyclosporine and how it relates to long-term clinical outcomes, both patient and societal.

18. Venkataram S, Awni WM, Jordan K, Rahman YE. Pharma-cokinetics of two alternative dosage forms for cyclosporine: liposomes and intralipid. J Pharm Sci. 1990;79:216-9.

19. Cavanak T, Sucker H. Cyclosporin. Formulation of dosage forms. Prog Allergy. 1986;38:65-72.

20. Curtis JJ, Barbeito R, Pirsch J, Lewis RM, Van Buren DH, Choudhury S. Differences in bioavailability between oral cyclosporine formulations in maintenance renal transplant patients. Am J Kidney Dis. 1999;34:869-74. *This study was important in demonstrating that there are differences in bioavailability of cyclosporine based on the formulation provided.

21. Hibberd AD, Trevillian PR, Roger SD, et al. Assessment of the bioequivalence of a generic cyclosporine A by a ran-domized controlled trial in stable renal recipients. Transplan-tation. 2006;81:711-7. *This study was important in demon-strating that there are differences in bioavailability of cyclosporine based on the formulation provided.

22. Taber DJ, Baillie GM, Ashcraft EE, et al. Does bioequiva-lence between modified cyclosporine formulations translate


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into equal outcomes? Transplantation. 2005;80:1633-5. **One of the most important trials in showing that patients receiving generic cyclosporine had a higher incidence of acute rejection.

23. Kahan BD, Welsh M, Schoenberg L, et al. Variable oral absorption of cyclosporine. A biopharmaceutical risk factor for chronic renal allograft rejection. Transplantation. 1996;62: 599-606.

24. Opelz G, Dohler B. Cyclosporine and long-term kidney graft survival. Transplantation. 2001;72:1267-73.

25. Helderman JH, Kang N, Legorreta A, Chen JY. Healthcare costs in renal transplant recipients using branded vs. generic cyclosporine. J Pharmacoecomonics. 2009 [in press].

26. Kasiske BL, Cohen D, Lucey MR, Neylan JF. Payment for im-munosuppression after organ transplantation. American Society of Transplantation. JAMA. 2000;283:2445-50. **This review highlights the implications of insufficient medication coverage for immunosuppressive medications posttransplantation.

27. Parker RE, Martinez DR, Covington TR. Drug product selection-Part 1: History and legal overview. Am Pharm. 1991;NS31:72-9.

esteban Frauca, et al.: Cytomegalovirus and Epstein-Barr Virus Infection in Pediatric Liver Transplants

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Cytomegalovirus and Epstein-Barr Virus Infection in Pediatric Liver TransplantsEsteban Frauca, Loreto Hierro and Paloma Jara

Hospital Infantil Universitario “La Paz”, Madrid, Spain


Correspondence to:

Paloma Jara

Servicio de Hepatología y trasplante

Hospital Infantil Universitario La Paz

P.o de la Castellana, 261

28046 madrid, españa


Abstract

Cytomegalovirus and Epstein-Barr virus infections remain one of the main concerns in the postoperative care of children with a liver transplantation. Most of the pediatric liver transplant recipients are seronegative for cytomegalovirus and/or Epstein-Barr virus at transplantation and this places them at marked risk for the development of cytomegalovirus/Epstein-Barr virus-related diseases. In immunosuppressed patients, cytomegalovirus presents a wide range of direct and indirect effects and cytomegalovirus infection is an independent risk factor for graft loss and death. However, the availability of effective therapies, sensitive assays for diagnosis and surveillance, together with the development of effective prevention strategies have dramatically decreased the impact of cytomegalovirus infection and disease on the outcome of pediatric liver transplant recipients and cytomegalovirus infection is no longer a significant cause of morbidity or mortality in these patients . In contrast, Epstein-Barr virus infection still represents a major cause of complications after transplantation due to its well-documented capacity to induce the development of lymphoproliferative disorders. Identifying those transplanted children at an actual risk of posttransplant lymphoproliferative disease development and defining effective and safe preventive strategies remain a challenge.Here, we describe the clinical consequences of these viral infections and their impact on the outcome of children with a liver transplantation and review the different promoted strategies for prevention and treatment. (Trends in Transplant. 2009;3:153-64)

Corresponding author: Paloma Jara, [email protected]

Key words

Cytomegalovirus. Epstein-Barr virus. Prophylaxis. Preemptive treatment. Children. Liver transplantation.


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Introduction

The current one-year survival rate for children with a liver transplant is around 90%1. Among the factors that have contributed to these results are the improvements in diagno-sis and management of infections. Transplant-ed children are especially vulnerable to viral infections and very particularly to certain herpes viruses: cytomegalovirus (CMV) and Epstein-Barr virus (EBV). Since most children are quite young when they are transplanted (around 50% are under two years of age) they are at a much higher risk for primary CMV and/or EBV infection in the immediate post-transplant period than adult patients.

Currently, despite the lack of standard-ized guidelines for prevention and treatment of CMV and EBV infections, most centers have significantly reduced the impact of these viruses on the outcomes of children with a liver transplant, but not to the same degree. Thus, while CMV infection or disease is no longer a significant cause of morbidity or mortality, EBV infection, due to its oncogenic capacity, still represents a clinical challenge in pediatric transplant programmes.

The root of this clinical difference lies in the different behavior under immunosuppres-sion of both viruses. Thus, while CMV disease is clearly related to the lytic replication of the virus, EBV-related disease (including lym-phoproliferative diseases) in transplanted pa-tients is more dependent on the uncontrolled expansion of EBV-transformed B-cells and less on lytic viral replication, and the current-ly available antivirals are only effective against lytic-driven replication.

This unequal success in preventing CMV and EBV infection results in a much higher infection rate for EBV than CMV (in our recent experience 92 and 8%, respectively, in the first year after transplantation). Thus,

CMV and EBV coinfection is currently a rare condition in children with liver transplant.

In the past, CMV infection has been as-sociated with a reactivation of other herpes viruses, such as EBV2,3, and CMV infection was reported to be one of the risk factors for post-transplant lymphoproliferative disease (PTLD) development in EBV-infected adult liver trans-plant recipients4. Unfortunately, published data regarding the role of CMV infection in the development of PTLD in pediatric liver trans-plant recipients are lacking.

Cytomegalovirus infection

Cytomegalovirus is a major cause of morbidity in patients with a solid organ trans-plant and CMV infection is an independent risk factor for graft loss and death. Direct ef-fects of CMV disease are associated with high CMV viremia and include both CMV syndrome and invasive disease. In contrast, the indirect effects are consequences of a viral immuno-modulatory effect on the recipient’s immune system. Through this mechanism, CMV has been implicated in acute and ductopenic chronic liver rejection, a higher predisposition to opportunistic infections, and development of lymphoproliferative disease in EBV-infected patients or in hepatitis C infection recurrence after liver transplantation5.

Most pediatric solid organ transplant recipients are CMV seronegative at transplan-tation (62% in our recent experience), so in most cases the CMV infection is due to a primary infection, newly acquired via the organ from a CMV-seropositive donor, blood products, or social contacts. Less frequently, it can be a reactivation of a latent virus acquired before transplantation or reinfection with a new strain.

The most influential risk factor for post-transplant CMV disease is the lack of preexisting


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specific CMV immunity in the CMV-seronega-tive recipients. Risk is further increased when a graft is received from seropositive donors (CMV D+/R). Other possible combinations, such as D–/R+ and D+/R+, are considered to be routine-risk or even low-risk as occurs in the case of D–/R–.

The use of grafts from a seropositive adult donor, whether a split or living-donor transplantation, is increasing in most pediatric liver transplant programs as a result of the scar-city of pediatric donors. This situation means that more and more liver transplanted children are a high-risk population for CMV infection.

Other predisposing factors are intense immunosuppression, or the occurrence of graft rejection or coinfection with other viruses such as human herpes virus-6 or hepatitis C virus. Once CMV infection is acquired, the risk for CMV disease appears to be directly re-lated with the CMV viral load6.

Before routine prophylaxis against CMV was implemented, primary symptomatic infection developed in 40% of all children with a liver transplant, with onset frequently oc-curring within the first three months after transplantation. The resulting mortality rates were as high as 20%7.

However, the availability of effective an-tiviral therapies, sensitive assays for infection diagnosis and surveillance, together with the development of effective prevention strategies have dramatically decreased the impact of CMV infection and disease on the outcome of pedi-atric solid organ transplant recipients. Nowa-days, most pediatric liver transplant programs present overall incidence rates of CMV disease of less than 20% and CMV disease is an ex-tremely rare cause of death in this population.

As a result of prophylaxis, an increase in the incidence of late-onset CMV disease, related to impairment in the recovery of CMV-specific

T-cell responses, has been reported. Thus, it developed in around 25% of the CMV D+/R– adult liver transplant recipients who received prophylaxis for three months8,9. In our experi-ence, 30% of the seronegative pediatric trans-plant recipients who received a three-month antiviral prophylaxis became CMV-infected after a median of six months after transplanta-tion, but only 25% of them presented symp-toms (mostly mild leucopoenia or thrombocy-topenia), and the symptoms resolved in all cases after a one-month treatment with val-ganciclovir (un-published data).

Currently, the most commonly used as-says for infection diagnosis and surveillance are CMV DNA detection by PCR in whole blood and pp65 CMV-antigenemia determina-tion in blood leucocytes. Both techniques have been demonstrated to be sensitive mark-ers, but it seems that most centers prefer PCR over antigenemia. The few studies performed in pediatric liver recipients have supported the usefulness of PCR in early detection of CMV, but an optimal cutoff value for starting antiviral treatment has not yet been estab-lished10.

Treatment

The current treatment of choice for CMV disease in children with a liver trans-plant consists of intravenous ganciclovir at a dose of 5 mg/kg twice-a-day for 3-4 weeks until two consecutive weekly PCR or antigen-emia negative results. Another potential op-tion for treatment of CMV disease, valganci-clovir, has been proven effective in adults, but no published studies have yet confirmed its efficacy in children11.

Cytomegalovirus resistance to ganciclo-vir, commonly due to mutations in the UL97 and UL54 CMV genes, is rising in adult patients. However, it has not been reported as a fre-quent complication in children.


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In cases of severe CMV disease, particu-larly with pulmonary involvement, treatment with hyperimmune CMV immunoglobulin (CMVIg) is indicated in addition to iv ganciclovir. If feasible, the degree of immunosuppression can also be decreased, but there are no stan-dardized guidelines.

Prevention of cytomegalovirus disease

Because of the potential serious conse-quences of CMV infection, prevention has be-come the cornerstone of infection management after transplantation. However, defining a standard of care for preventing CMV disease remains controversial and undefined. There are two major strategies: universal prophylaxis and preemptive treatment. The former consists in the administration of an antiviral agent for a long period of time to all transplanted children irrespective of the individual risk for CMV disease, with the objective of avoiding both CMV infection and disease in a period of time when recipients are under intense immuno-suppression. Prophylaxis suppresses viremia, thereby preventing direct, and maybe indirect, effects of CMV, and it is also likely to prevent other herpes virus infections such as EBV. Limitations of this approach include the poten-tial toxicity of antivirals, the risk of resistance development, and the possible development of a late-onset CMV disease.

Preemptive treatment relies on strict surveillance to detect the appearance of CMV infection and, upon detection, antiviral therapy is started to prevent a progression to symptomatic CMV disease. It requires longitudinal and frequent monitoring of CMV infection and its success depends on the sensitivity and specificity of the viral marker to predict CMV disease. Again, little has been published regarding the pediatric population. A possible drawback of preemptive therapy is that it may not be entirely effective in

preventing indirect CMV effects since low-grade viral replication may not be detected and therefore not treated.

Both strategies have demonstrated high efficacy in preventing CMV disease in adult recipients after liver transplantation. However, a recent survey of 58 different liver transplant programs in North America indicated that most of the centers prefer prophylaxis instead of preemptive treatment for high- and routine-risk patients12.

There are no large controlled pediatric studies with statistically reliable data that can support any superiority of one of these strate-gies over the other. Only one trial is available to compare prophylaxis and preemptive treat-ment in children. In this recently published study, a group of 21 pediatric patients with a liver transplant were randomized to receive prophylaxis (ganciclovir for 30 days) followed by preemptive treatment (ganciclovir on reach-ing a threshold of 100,000 DNA copies/ml whole blood) or preemptive treatment alone. No case of CMV disease was diagnosed in either arm and the CMV-infection rates were similar (70% in the prophylaxis arm versus 81% in the preemptive alone treated group), but there was a significant increase in the median total number of days of ganciclovir in the prophylaxis plus preemptive treatment group. On the basis of their results, the authors recommended preemptive therapy over prophylaxis13.

However, beyond this limited experi-ence, the current strategies used in pediatric transplant programs are mainly based on the results of trials in adults14,15. Some of these studies have shown that preemptive treatment may not be effective in certain CMV D+/R– adults with a liver transplant since viral repli-cation can be so active and rapid that it may produce symptomatic disease prior to detec-tion, even with a weekly monitoring scheme. In one study, nearly 25% of CMV D+/R– patients


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who developed CMV disease could not be detected early by PCR16. This finding is high-ly relevant in transplanted children since a high proportion of them are CMV-seronega-tive at transplantation. Indeed, prophylaxis is currently recommended in all D+/R– re-cipients by the American Society of Trans-plantation17.

An additional important benefit of CMV prophylaxis in children is that of preventing other herpes-group virus infections with a po-tentially severe impact on outcome such as Epstein-Barr virus or human herpes virus-6.

Multiple prophylaxis strategies with dif-ferent combinations of antiviral drugs and doses have been used by the different trans-plantation programs over the years. Currently, the most extended prophylaxis regime con-sists in a short course of iv ganciclovir fol-lowed by long-term therapy with oral antivi-rals. However, a study in liver transplanted children treated with either two weeks of iv ganciclovir followed by 50 weeks of high-dose oral acyclovir or two weeks of iv ganciclovir alone did not find an added beneficial effect of long-term prophylaxis on the incidence of CMV-disease18.

Nevertheless, the availability of new oral antivirals, such as ganciclovir or, more recently, valganciclovir, with a superior capacity for inhibiting CMV replication than acyclovir, combined with the good results obtained from trials on adult recipients19, have prompted the inclusion of these drugs in prophylactic protocols in children. The poor bioavailability of oral ganciclovir (under 10%) and the lack of a liquid formulation have limited its use in children. On the contrary, valganciclovir, a valine ester of ganciclovir, has demonstrated a tenfold increase in intestinal absorption, resulting in blood levels comparable to iv ganciclovir. Besides, a liquid presentation has recently been approved, providing a chance to treat small children.

There is still limited experience with the use of oral valganciclovir in children. A prospective multicentre trial enrolled 63 pediatric solid organ transplant recipients at high risk for CMV infection. All of them received treat-ment with valganciclovir up to 100 days post-transplantation with a 26-week follow-up. The incidence of CMV infection was 11%, mostly after ceasing valganciclovir, and there were no cases of CMV disease. Another important point was that the dosing algorithm used to adjust the body surface and renal function provided a ganciclovir exposure similar to that considered safe and effective in adult transplant recipients. The most frequent valganciclovir-related adverse effects were diarrhea (10%) and neutropenia (5%)20.

In contrast to antivirals, the role for immunoglobulin preparations used alone or in combination with antiviral drugs to prevent CMV infection is much less defined. Thus, a recent review of all the published trials, which included a large number of solid or-gan transplant recipients, showed that im-munoglobulin did not reduce the risk of CMV disease compared with either no treatment or placebo, and that the combination of CM-VIg with antivirals (acyclovir or ganciclovir) had no additional benefits in preventing CMV disease or all-cause mortality compared to the use of antivirals alone21. The few trials conducted in children have not shown a significant benefit of immunoglobulins in preventing CMV disease22,23.

Hybrid strategies represent a promising alternative, combining the advantages of pro-phylaxis and preemptive treatment. In this context, a recently published retrospective study described the experience with a hybrid prevention strategy in 119 pediatric liver trans-plant recipients (84 CMV-seronegative), com-bining a minimum of 14 postoperative days iv ganciclovir followed by CMV viremia monitoring, biweekly for the first three months, monthly for the rest of the first year, and every three


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months thereafter. Children with detectable CMV DNA restarted iv ganciclovir until they became negative or symptoms ceased in CMV-disease cases. After a median follow-up of 2.3 years, the overall incidence for CMV infection was 34.4% (58% for the D+/R– sub-group) with 9.8% for the disease24.

In conclusion, since most pediatric liver recipients are seronegative for CMV and EBV pretransplantation and so are at high risk for both viral diseases, it seems reasonable to consider prophylaxis the best strategy. Un-settled points, such as the best antiviral regi-men and its duration, need to be defined. No synergy between immunoglobulins and antivi-rals has been demonstrated in CMV prophy-laxis. Preemptive strategies seem to be a promising and cost-effective approach, but demand extremely careful infection surveil-lance, which would probably limit their use in children (number of venipunctures) and, more importantly, there are doubts related to their efficacy in D+/R– recipients. Well-designed hy-brid strategies may represent a valuable al-ternative to the currently extended use of pro-phylaxis.

Finally, another important consideration is that contrary to adult patients, children are at high risk for other herpes virus (i.e. EBV) related disease, so any decision we take in CMV management can have an impact, positive or negative, on these other infections.

Epstein-Barr virus infection

Epstein-Barr virus infection remains one of the main concerns in the postoperative care of children with a liver transplant because of the well-documented capacity of this virus to induce PTLD. This term defines a wide spectrum of diseases, from reactive polyclonal hyperplasia to diffuse lymphoma, characterized by an uncontrolled proliferation of EBV-trans-formed lymphocytes (B-cells in most cases).

The currently reported incidence of PTLD ranges from 5-15% and about 80% of PTLD cases have been reported to develop in the first two years after transplantation. Posttransplant lymphoproliferative disease has an overall mortality rate that has decreased from as high as 60% in old series to around 10-20% in the more recent ones25-28. It has been recognized as an independent risk factor for graft loss and death in a large series of liver transplanted children and it is the most frequent tumor in this population (around 50% of all tumors)29.

Other potentially important conse-quences of EBV infection are those derived from treating it, such as the risk for graft re-jection secondary to the reduction of the immunosuppression treatment.

Briefly, the imbalance between viral infec-tion and the deteriorated EBV-specific T-cell-based host surveillance caused by inappro-priate immunosuppression is the main causal mechanism for PTLD. As a result of it, EBV-infected cells are deficiently controlled by the immune response and eventually may prolifer-ate and result in PTLD30.

Several factors have been associated with an increase in the incidence of PTLD; the most decisive is primary EBV infection. In-deed, severe EBV infection and PTLD occur 10-20 times more frequently in patients who were seronegative at transplantation. Other reported risk factors are intense immunosup-pression or CMV disease.

The current standard for diagnosis and monitoring of EBV infection in transplanted children is measurement of EBV DNA in whole blood by real time polymerase chain reaction (RT-PCR).

A majority (60-80%) of pediatric liver recipients is EBV seronegative at transplanta-tion, and more than 75% of them develop a primary infection in the first six months after


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transplantation. In the case of EBV-seroposi-tive recipients, only 20-30% of them become reinfected. Most of these primary infections or reinfections are asymptomatic and only around 20% present with a great diversity of symptoms, ranging from the unspecific (fever, weight loss, anorexia) to a more specific infectious mononucleosis syndrome or a frank PTLD.

After either asymptomatic infection or the resolution of clinically symptomatic infec-tion or PTLD, some children maintain persis-tently elevated EBV viral loads for a long time. Among these are a group of high viral load carriers, defined as those that maintain high viremia levels for more than six months and who have been reported to represent 18-41% of the whole population. In this group, two studies respectively reported PTLD rates of 3 and 25% for liver transplant recipients and up to 45% in another study on a group of heart transplanted children. In contrast, these studies did not find cases of PTLD among children whose viremia was either a low pos-itive or negative31-33.

At the present time, it is not entirely known what the clinical significance of this chronic high-viremia carriage is, but the reported higher incidence of PTLD in this subpopulation converts these patients into the main target for a strict surveillance of PTLD and preemptive treatment. Identifying the ones who are at a real risk of PTLD among these high-load EBV carriers remains a challenge.

Management of Epstein-Barr virus infection in children with a liver transplant

Due to the poor outcome associated with PTLD once it is diagnosed, efforts have been directed to develop preventive strate-gies. Thus, the goals of management are re-ducing the incidence of EBV infection, or at

least minimizing its consequences, and above all preventing PTLD development while main-taining the graft rejection-free.

The best strategy for PTLD prevention has not yet been established, mainly because its low incidence makes statistically strong trials (randomized or cohort studies) prohibitive in terms of time and cost. Thus, many of the available studies have relied on historical control groups of patients at single centers or include only a small number of patients.

Different sequential approaches, such as pretransplant and posttransplant pro-phylaxis and preemptive treatment, are considered.

Pretransplant prophylaxis

At this time there is not an option for pretransplant prophylaxis in EBV-seronegative recipients since a vaccine is not yet available. Nevertheless, there are some trials in course (phase I/II) with vaccines based on different lytic (gp350) or latent (EBNA2, EBNA-3C) viral proteins34,35.

Posttransplant prophylaxis

No published study to date has demon-strated a significant positive influence in pre-venting EBV infection or PTLD in association with any specific protocol for primary immu-nosuppression36,37.

On the contrary, the effect of the overall intensity of immunosuppression on PTLD rates has been demonstrated. Thus, a low-dose im-munosuppressive protocol with lower than usual target cyclosporine or tacrolimus blood levels resulted in a significant reduction in the incidence of PTLD38. However, it may present excessive risk for rejection beyond its potential benefits. Not every transplanted child has the


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same risk of PTLD; thus an individual evaluation of the risk/benefit relation before applying low-dose immunosuppression makes sense. On the other hand, it has been also demonstrated that intensive immunosuppression, such as the use of cytotoxic antibodies like OKT3, significantly predisposes to PTLD39.

Antiviral prophylaxis

The theoretical objective of prophylaxis is that of preventing, or at least reducing, the transmission of replicative viruses from the transplanted organ or blood products to the recipient’s B-cells and thus preventing their expansion. However, since we know that most of the recipients will become infected in the first months after transplantation, a more real-istic approach would probably be to just mod-ify or delay that primary EBV infection during the first months after liver transplantation when immunosuppression is heaviest.

Antivirals are currently used in many centers as simultaneous prophylaxis for CMV and EBV infection. However, the studies designed to assess the effectiveness of anti-virals on EBV-infection prophylaxis have had variable results.

The only published randomized trial that compared the efficacy of a sequential prophylaxis consisting of two weeks of iv gan-ciclovir followed by 50 weeks of oral acyclovir with two weeks of iv ganciclovir alone in liver transplanted children found similar symptom-atic EBV-disease rates in both groups (33% for the combined treatment and 21% for the group treated only with ganciclovir; p = NS), concluding that a long prophylaxis regimen did not represent any advantage in preventing EBV disease40.

However, several nonrandomized trials suggest that antiviral prophylaxis may play a role in preventing EBV disease or PTLD41-43.

In a case-control study in a large cohort of children and adults with a kidney transplant, a significant decrease in the incidence of early PTLD (< 1 year after transplant) was found in those patients that had been treated with either ganciclovir or acyclovir compared to those who had not received antiviral pro-phylaxis, with an up to 82% reduction in the risk of PTLD, depending on the antiviral agent. However, a protective effect for late-onset PTLD was not demonstrated.

A second option for preventing EBV dis-ease and PTLD that has been evaluated is im-munoprophylaxis using intravenous EBV-en-riched antibody gamma globulin. This option is based on the observation that although cyto-toxic T-cells play the main role in controlling EBV infection, some reports have document-ed an increased risk for PTLD in patients un-able to produce antibodies against certain EBV antigens (i.e. EBV nuclear antigen; EBNA)44. Two randomized trials comparing the treatment with CMVIg with placebo have been published and both of them showed little benefit from immunoglobulin in prevent-ing PTLD23,45.

In conclusion, the available data indi-cate that antiviral prophylaxis does not pre-vent EBV infection or reinfection and a high proportion of children (60-90%) become in-fected in the first six months after liver trans-plantation. But, in the absence of randomized trials to confirm it, it seems that prophylaxis reduces the incidence of early PTLD. At any rate, it prevents a reported risk factor for EBV infection, namely CMV. However, some as-pects of prophylaxis, such as the specific an-tiviral protocol or the prophylaxis duration, remain undefined.

Preemptive treatment

The objective of preemptive treatment is to prevent the development of PTLD once


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the EBV infection is detected. Considering the fact that a majority of transplanted children will acquire EBV infection, it is fundamental to identify the ones with an increased risk for PTLD and who therefore would be candidates for this type of treatment.

The current practice for EBV-infection surveillance after transplantation in most cen-ters is longitudinal monitoring of viral load in peripheral blood with DNA amplification tech-niques. This practice is based on the well-documented correlation that exists between a sustained viral load increase plus high EBV DNA levels with an increased risk of PTLD, and that there is usually a variably long gap in time between EBV-viral load increases to high levels and the development PTLD46-50.

Nowadays, RT-PCR is the standard as-say for detection and quantitation of EBV viral load. Current recommendations include fre-quent monitoring during the first year after a transplant when the patient is at greatest risk (at two-week intervals for the first three months, then monthly until one year) and not so fre-quent (every 3-4 months) thereafter.

However, the main limitation of this technique is that of a poor positive-predictive value of 50-70% in contrast with its excellent negative-predictive value of 95-100%. This means that an increased viral load is not al-ways predictive of impending PTLD. This lack of specificity has precluded the search for alternative markers that would more accurate-ly evaluate PTLD risk among high viral load carriers. Thus, the detection of a low specific anti-EBV cellular immune response using anti-EBV T lymphocyte quantitation in peripheral blood, combined with the detection of a high EBV viral load, has significantly increased the specificity for predicting PTLD development compared with DNA measurement alone.

The chance to identify patients at risk prior to the appearance of clinical disease has

led to the investigation of different preemptive approaches to prevent EBV-related compli-cations, but up until now there is no general consensus regarding the best strategy. Basi-cally, the treatment modalities used by most centers are immunosuppression reduction, antiviral treatment, or a combination of both.

However, the lack of randomized con-trolled trials that permit a comparison of the effectiveness of the different strategies, as well as the combined use of these in some published studies, makes it difficult to extract conclusions.

There is general agreement on the ben-eficial effects of reducing immunosuppression in these patients to restore their capacity for an EBV-specific immunologic response that would be effective against both the lytic-phase virus and the latently infected B-cells. How-ever, the risk of developing an acute graft rejection in some high EBV-viremia carriers who are nevertheless not at real high-risk for PTLD is the major limitation of this strategy and must be considered. This approach re-quires a close and very careful monitoring of immunosuppressor blood levels and liver function tests for an early diagnosis of a potential graft rejection. Timing of immunosuppression restoration is still not determined and currently it mostly depends on the appearance of the first signs of rejection. Thus, the availability of more accurate tests for monitoring the degree of immunosuppression and improving the criteria for identifying the children at an actual high risk for PTLD beyond the present-day standards (PCR) should improve the safety of this strategy in the future.

The results obtained in a group of 43 liver transplanted children (40% EBV-seronegative at transplant) with a median follow-up of 26 months support this approach. Their immunosuppression was tapered (tacrolimus trough levels 4-6 ng/ml) when high viremia levels (> 4,000 copies/µg DNA) were detected. The PTLD incidence in


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this group was 2.3%, significantly lower than the historical rate of 16% (p < 0.05) and the acute rejection incidence was very low (2.3%)51.

Antivirals, either alone or associated with tapered immunosuppression, have been considered by some centers as an alternative for PTLD-preemptive treatment. However, the potential efficacy of this strategy is more con-troversial since antiviral drugs (ganciclovir or valganciclovir) act by means of inhibiting the lytic-EBV replication cycle and have no effect on EBV-infected lymphocytes in the latent state of the infection. Therefore, the efficacy of antivirals in preventing PTLD in asymptom-atic children with a high viral load will depend on the role, if any, that lytic viral replication plays in the development of the lymphoprolif-erative process, or whether this process is only a consequence of the proliferation of the latent virus-infected B-cells. At present, the concrete mechanism that triggers PTLD is not completely defined, but some data from dif-ferent studies could support the intervention of viral lytic replication52,53. Thus, RNA tran-scripts of genes involved in EBV-lytic replica-tion were identified in peripheral blood lym-phocytes of liver transplanted children, all of them high-viral load carriers that ultimately developed PTLD, as if latent EBV enters a replicative cycle with B-cell cellular division.

Several non-controlled studies support the use of different antiviral-based protocols as preemptive treatment for EBV-related PTLD. Thus, in one of these studies, a combined treatment with iv ganciclovir and reduction of immunosuppression in children with liver transplantation and a rising viral load detect-ed by prospective PCR monitoring resulted in a drop in the incidence of PTLD from a his-torical 10% down to 5%54.

Another study, in this case in children with an intestinal transplant, showed a reduc-tion in PTLD incidence from 46 to 23% after a combined preemptive treatment with iv

ganciclovir and CMVIg, without modifying the immunosuppression55.

The recently available oral valganciclovir allows long-term treatment, without a need of hospitalization, for small children. A few studies have recently been published using valganci-clovir as preemptive treatment of EBV-induced PTLD in children. A retrospective study on a continued treatment (7.2 ± 3.8 months) with valganciclovir (520 mg/m2 twice daily), without modification of immunosuppression in liver transplanted children with a chronic EBV infection (72% asymptomatic) and EBV DNA detected by qualitative PCR and a follow-up 12 months after therapy was started, reported an overall incidence of PTLD of 2.3% opposed to a historical rate of 5.1%. The treatment was well-tolerated, with no severe effects attributable to valganciclovir, and neutropenia was the most frequent adverse effect (12%)56.

More recently, a 30-day preemptive treatment with valganciclovir in pediatric liver recipients with a PCR-detected high EBV DNA resulted in a completely negative EBV DNA in 34% of the children, a reduction of at least 50% of the value in 41% of the children, and no change in the remaining 23%. In a non-treated historical group, the results were 6, 25, and 68%, respectively (p = 0.01). Other interesting findings of this preliminary study were that EBV viral load was directly related with valganciclovir blood levels, and that most children did not achieve the recommended levels and needed an increase in their valgan-ciclovir dose. Thus, the authors recommended monitoring valganciclovir blood levels in order to optimize treatment57.

The current protocol in our centre for preventing PTLD after liver transplantation in children consists in a six-month antiviral prophylaxis (one month iv ganciclovir and five months valganciclovir) with EBV DNA monitoring by RT-PCR (monthly for the first three months after transplant and every three


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months thereafter) and restart of valganciclovir upon detection of EBV DNA, combined with a reduction in immunosuppression in those cases with detected high viral load (> 16,000 copies/ml). A group of 25 consecutive first-liver graft recipients (64% were EBV-seronegative at transplantation) were prospectively followed-up for one year. Most children (92%) became EBV-infected in the first year after transplanta-tion, and 61% showed high EBV DNA values. Only one patient presented EBV-related symptoms and there were no cases of PTLD (non-published data).

Finally, new treatment modalities like adoptive immunotherapy with autologous EBV-specific cytotoxic T lymphocytes or anti-CD20 antibody treatment offer certain future possibilities, based on the promising results of some published trials58-60. However, it is reasonable to think that the technical difficulty and/or elevated cost and/or potential second-ary effects of these new treatments will neces-sitate a marked improvement in our capacity to better identify the patients at actual high risk for PTLD.

In conclusion, reduction of immunosup-pression is considered the mainstay in the management of liver transplanted children with EBV infection and a high viral load. Anti-virals may also play a role in controlling EBV viremia and thus preventing PTLD and its ef-ficacy should be confirmed in future controlled trials on large series of patients so that differ-ent treatment options can be compared.

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2. Aalto SM, Linnavuori K, Peltola H, et al. Immuno-reactivation of Epstein-Barr due to CMV-primary infection. J Med Virol. 1998;56:186-91.

3. Pascher A, Klupp J, Schulz RJ, et al. HHV-6 and HHV-7 infections after intestinal transplantation without specific an-tiviral prophylaxis. Transplant Proc. 2004;36:381-2.

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25. Malatack JJ, Gartner JC, Urbach AH, Zitelli BJ. Orthotopic liver transplantation Epstein-Barr virus, cyclosporine, and lymphoproliferative disease: A growing concern. J Pediatr. 1991;118:667-75.

26. Paya CV, Fung JJ, Nalesnik MA, et al. Epstein-Barr virus-induced posttransplant lymphoproliferative disorders. Trans-plantation. 1999;68:1517-25.

27. Smets F, Bodeus M, Goubau P, Reding R, Otte JB, Buts JP. Characteristics of Epstein-Barr virus primary infection in pediatric liver transplant recipients. J Hepatol. 2000; 32:100-4.

28. Younes BS, McDiarmid S, Martin MG, Vargas JH, Goss JA, Bussutil RW. The effect of immunosuppression on posttrans-plant lymphoproliferative disease in pediatric liver transplant patients. Transplantation. 2000;70:94-9.

29. Wallot MA, Mathot M, Janssen M, et al. Long term survival and late graft loss in pediatric liver transplant recipients – a 15 year single-center experience. Liver Transpl. 2002;8:615-22.

30. Thorley-Lawson DA, Gross A. Persistence of the Epstein-Barr virus and the origins of associated lymphomas. N Engl J Med. 2004;350:1328-13. *Review of EBV dynamics and pathogenesis of PTLD.

31. D’Antiga L, Del Rizzo M, Mengoli C, Cillo U, Guariso G, Zancan L. Sustained Epstein-Barr virus detection in pediat-ric liver transplantation. Insights into the occurrence of late PTLD. Liver Transpl. 2007;13:343-8.

32. Bingler MD, Miller SA, Quivers E, et al. Chronic high Epstein-Barr viral load state and risk for late onset posttransplant lymphoproliferative disease/lymphoma in children. Am J Transplant. 2008;8:442-5.

33. Green M, Soltys K, Rowe DT, Webber SA, Mazariegos G. Chronic high Epstein-Barr viral load carriage in pediatric liver transplant recipients. Pediatr Transplant. 2009; 13:319-23.

34. Lockey TD, Zhan X, Surman S, Sample CE, Hurwitz JL. Epstein-Barr virus vaccine development: a lytic and latent protein cocktail. Front Biosci. 2008;13:5916-27.

35. Sokal EM, Hoppenbrouwen K, Vandermeulen C, et al. Re-combinant gp350 vaccine for infectious mononucleosis: a phase 2 randomized, double blind, placebo-controlled trial to evaluate the safety, immunogenicity and efficacy of an Epstein-Barr virus vaccine in healthy young adults. J Infect Dis. 2007;196:1749-53.

36. Kelly D, Jara P, Rodeck B, et al. Tacrolimus and steroids versus cyclosporine microemulsion, steroids and azathio-prine in children undergoing liver transplantation. Random-ized European multicenter trial. Lancet. 2004;364:1054-61.

37. Jain A, Mazariegos G, Kashyap R, et al. Pediatric liver trans-plantation. Transplantation. 2002;73:941-7.

38. Ganschow R, Schulz T, Meyer T, Broering DC, Burdelski M. Low-dose immunosuppression reduces the incidence of post-transplant lymphoproliferative disease in pediatric liver graft recipients J Pediatr Gastroenteril Nutr. 2004;38: 198-203.

39. Praghakaran K, Wise B, Chen A, et al. Rational management of post-transplant lymphoproliferative disorders in pediatric recipients. J Pediatr Surg. 1999;34:112-16.

40. Green M, Kaufmann M, Wilson J, Reyes J. Comparison of intravenous ganciclovir followed by oral acyclovir with intra-venous ganciclovir alone for prevention of cytomegalovirus and Epstein Barr virus disease after liver transplantation in children. Clin Infect Dis. 1997;25:1344-9.

41. Funch DP, Walker AM, Schneider G, Ziyadeh NJ, Pescovitz MD. Ganciclovir and acyclovir reduce the risk of post-trans-plant lymphoproliferative disorder in renal transplant pa-tients. Am J Transplant. 2005;5:2894-900.

42. Darenkov IA, Macarelli MM, Bassadona GP, et al. Reduced incidence of Epstein Barr virus-associated posttransplant lymphoproliferative disorder in preemptive therapy. Trans-plantation. 1997;64:848.

43. Davis CL, Harrison KL, McVicar JP, Forg P, Bronner M, Marsh CL. Antiviral prophylaxis and the Epstein-Barr virus-related lymphoproliferative disorder. Clin Transplant. 1995;9:53.

44. Ridler SA, Breinig MC, McKnight JLC. Increased levels of circulating Epstein-Barr virus infected lymphocytes and de-creased EBV nuclear antigen antibody responses are as-sociated with development of posttransplant lymphoprolif-erative disease in solid organ transplant recipients. Blood. 1994;84:972-84.

45. Humar A, Hebert D, Davies HD, et al. A randomized trial of ganciclovir versus ganciclovir plus immune globulin for prophylaxis against Epstein-Barr virus related posttrans-plant lymphoproliferative disorder. Transplantation. 2006; 81:856-81.

46. Savoie A, Perpate C, Carpenter L, Joncas J, Alfieri C. Direct correlation between the load of Epstein-Barr virus infected lymphocytes in the peripheral blood of pediatric transplant patients and risk of lymphoproliferative disease. Blood. 1994;83:2715-22.

47. Green M, Bueno J, Rowe D, et al. Predictive negative value of persistent low Epstein-Barr virus viral load after intestinal transplantation in children. Transplantation. 2000; 70:593-96.

48. Scheenstra R, Verschuuren EA, de Haan A, et al. The value of prospective monitoring of Epstein-Barr virus DNA in blood samples of pediatric liver transplant recipients. Transpl In-fect Dis. 2004;6:15-22.

49. Xu S, Green M, Kingsley L, Webber S, Rowe D. A compari-son of quantitative-competitive and real time PCR assays using an identical target sequence to detect Epstein-Barr virus viral load in the peripheral blood. J Virol Methods. 2006;137:205-12.

50. Kogan L, Burroughs M, Emre S, Moscona A, Shneider BL. The role of quantitative Epstein-Barr virus polymerase chain reaction and preemptive immuno suppression reduction in pediatric liver transplantation: a preliminary experience. J Pediatr Gastroenterol Nutr. 2001;33:445-9.

51. Lee T, Savoldo B, Rooney CM, et al. Quantitative EBV viral loads and immunosuppression alterations can decrease PTLD incidence in pediatric liver transplant recipients. Am J Transplant. 2005;5:2222-8. *First trial that analyzed the efficacy on preventing PTLD of a tapered immunosuppres-sion in children with LT.

52. Vajro P, Lucariello S, Migliano F. Predictive value of Epstein-Barr virus genome copy number and BZLF1 expression in blood lymphocytes of transplant recipients at risk for lym-phoproliferative disease J Infect Dis. 2000;181:250-4.

53. Hopwood P, Brooks L, Parratt R, et al. Persistent Epstein-Barr virus infection: unrestricted latent and lytic viral gene expression in healthy immunosuppressed transplant recipi-ents. Transplantation. 2002;74:194-202.

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58. Comoli P, Basso S, Zecca M, et al. Preemptive treatment of EBV-related lymphoproliferative disease after pediatric hap-loidentical stem-cell transplantation. Am J Transplant. 2007;7:1648-53.

59. Savoldo B, Goss JA, Hammer MM, et al. Treatment of solid organ transplant recipients with autologous Epstein-Barr virus specific cytotoxic T lymphocytes (CTLs). Blood. 2006; 108:2942-9.

60. Comoli P, Labirio M, Basso S, et al. Infusion of autologous Epstein-Barr virus (EBV) specific cytotoxic T cells for pre-vention of EBV-related lymphoproliferative disorder in solid organ transplant recipients with evidence of active virus replication. Blood. 2002;99:2592-8.

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VALCYTE 50 mg/ml polvo para solución oral. VALCYTE 450 mg comprimidos con cubierta pelicular. COMPOSICIÓN CUALITATIVA Y CUANTITATIVA: VALCYTE polvo para solución oral: cada frasco contiene 5,5 g de hidrocloruro de valganciclovir, por 12 g de polvo para solución oral. La solución reconstituida contiene 50 mg por ml de valganciclovir (como hidrocloruro). VALCYTE comprimidos con cubierta pelicular: cada comprimido contiene 496,3 mg de hidrocloruro de valganciclovir, equivalente a 450 mg de valganciclovir (base libre). Para consultar la lista completa de excipientes, ver apartado lista de excipientes. FORMA FARMACÉUTICA: VALCYTE polvo para solución oral: polvo para solución oral. El polvo es un granulado de color blanco a ligeramente amarillento. Cuando el polvo es disuelto, la solución es clara, de incolora a parda. VALCYTE comprimidos con cubierta pelicular: comprimidos con cubierta pelicular. Comprimidos con cubierta pelicular de color rosa, convexo y ovalado, con el grabado “VGC” en una cara y “450” en la otra. DATOS CLÍNICOS: Indicaciones terapéuticas VALCYTE está indicado para el tratamiento de inducción y mantenimiento de la retinitis por citomegalovirus (CMV) en pacientes con síndrome de inmunodeficiencia adquirida (SIDA). VALCYTE está indicado para la prevención de la enfermedad por CMV en pacientes seronegativos al CMV que han recibido un trasplante de órgano sólido de un donante seropositivo. Posología y forma de administración: Advertencia – se deben seguir estrictamente las recomendaciones sobre la posología para evitar sobredosificación (ver apartados Advertencias y precauciones especiales de empleo y Sobredosis). Después de su administración oral, el valganciclovir se metaboliza de forma rápida y extensa a ganciclovir. 900 mg de valganciclovir por vía oral, dos veces al día, es equivalente terapéuticamente a 5 mg/kg de ganciclovir administrado dos veces al día. La exposición sistémica a ganciclovir con 900 mg de valganciclovir solución oral es equivalente a 900 mg de valganciclovir en comprimidos. Posología habitual en adultos: Tratamiento de inducción de la retinitis por CMV: La dosis recomendada para los pacientes con retinitis activa por CMV es de 900 mg de valganciclovir dos veces al día durante 21 días (en el caso de Valcyte comprimidos con cubierta pelicular: dos comprimidos de 450 mg). Un tratamiento prolongado de inducción puede incrementar el riesgo de toxicidad para la médula ósea (ver apartado Advertencias y precauciones especiales de empleo). Tratamiento de mantenimiento de la retinitis por CMV: Después del tratamiento de inducción, o si se trata de pacientes con retinitis inactiva por CMV, se recomienda administrar una dosis de 900 mg de valganciclovir una vez al día (en el caso de Valcyte comprimidos con cubierta pelicular: dos comprimidos de 450 mg). Se puede repetir el tratamiento de inducción en aquellos pacientes en los que la retinitis empeore; sin embargo, se debe tener en cuenta la posibilidad de resistencia viral al fármaco. Prevención de la enfermedad por CMV en el trasplante de órgano sólido: La dosis recomendada en pacientes que han recibido un trasplante es de 900 mg una vez al día (en el caso de Valcyte comprimidos con cubierta pelicular: dos comprimidos de 450 mg), comenzando dentro de los 10 días del trasplante y continuando hasta los 100 días post-trasplante. Instrucciones posológicas especiales: Pacientes con insuficiencia renal: Los niveles séricos de creatinina o el aclaramiento de creatinina se deben vigilar cuidadosamente. El aclaramiento estimado de creatinina (ml/min) se puede calcular según la creatinina sérica mediante las siguientes fórmulas: para los varones = (140 – edad [años]) x (peso corporal [kg])/(72) x (0,011 x creatinina sérica [micromoles/l]). Para las mujeres = 0,85 x valor de los varones. VALCYTE polvo para solución oral: hay que ajustar la posología según el aclaramiento de creatinina, tal y como se indica en la siguiente tabla (ver apartado Advertencias y precauciones especiales de empleo).

VALCYTE comprimidos con cubierta pelicular: Hay que ajustar la posología según el aclaramiento de creatinina, tal y como se indica en la siguiente tabla (ver apartado Advertencias y precauciones especiales de empleo).

Pacientes sometidos a hemodiálisis: VALCYTE polvo para solución oral: es necesario ajustar la dosis para pacientes en hemodiálisis (CrCl < 10 ml/min) (ver apartado Advertencias y precauciones especiales de empleo) en la tabla anterior se da una recomendación de dosis. VALCYTE comprimidos con cubierta pelicular: para pacientes en hemodiálisis (CrCl < 10 ml/min) no se puede dar una recomendación de dosis. Por consiguiente, Valcyte comprimidos con cubierta pelicular no se debe emplear en estos pacientes (ver apartado Advertencias y precauciones especiales de empleo). Pacientes con disfunción hepática: La seguridad y eficacia de VALCYTE no ha sido estudiada en pacientes con disfunción hepática (ver apartado Advertencias y precauciones especiales de empleo). Niños y adolescentes (menores de 18 años): VALCYTE no está recomendado para uso en niños menores de 18 años debido a la escasez de datos sobre seguridad y eficacia en esta población de pacientes.( ver apartado Advertencias y precauciones especiales de empleo). Pacientes ancianos: La seguridad y la eficacia de VALCYTE se desconocen en esta población. Pacientes con leucopenia, neutropenia, anemia, trombocitopenia y pancitopenia graves: Antes de comenzar el tratamiento, ver apartado Advertencias y precauciones especiales de empleo. Si se produce un deterioro significativo del recuento de células sanguíneas durante el tratamiento con VALCYTE, se deberá considerar el empleo de factores de crecimiento hematopoyético y/o una suspensión de la medicación (ver apartado Advertencias y precauciones especiales de empleo). Forma de administración: VALCYTE se administra por vía oral, y siempre que sea posible, debe tomarse con alimentos. VALCYTE polvo para solución oral: requiere ser reconstituido antes de su administración oral (ver apartado Precauciones especiales de eliminación y otras manipulaciones ). Se incluye dos dispensadores orales con graduación desde 25 mg hasta 500 mg. Se recomienda que el paciente use el dispensador. VALCYTE comprimidos con cubierta pelicular: Los comprimidos no se deben romper ni triturar. Contraindicaciones: VALCYTE está contraindicado en pacientes con hipersensibilidad a valganciclovir, ganciclovir o a alguno de los excipientes. Debido a la semejanza en la estructura química de VALCYTE y de aciclovir y valaciclovir, es posible que ocurra una reacción de hipersensibilidad cruzada entre estos medicamentos. Por lo tanto, VALCYTE está contraindicado en pacientes con hipersensibilidad a aciclovir y valaciclovir. VALCYTE está contraindicado durante la lactancia (ver apartado Embarazo y lactancia). Advertencias y precauciones especiales de empleo: Debido a su carácter teratogénico, el polvo de VALCYTE y la solución reconstituida deben manejarse con precaución. Si el polvo o la solución contactan directamente con la piel, esta zona debe lavarse a fondo con agua y jabón. Si la solución entra en los ojos, los ojos deben lavarse de forma inmediata con agua abundante. Antes de iniciar el tratamiento de valganciclovir, se debe advertir a los pacientes del riesgo potencial para el feto. En estudios con animales, se ha observado el poder mutágeno, teratógeno, espermatogénico, carcinógeno, y supresor de la fertilidad femenina del ganciclovir. Por tanto, VALCYTE debe considerarse como un potencial teratógeno y carcinógeno para el ser humano, con potencial para ocasionar malformaciones congénitas y cáncer. Además, es probable que VALCYTE inhiba la espermatogénesis de forma transitoria o permanente. Se debe recomendar a las mujeres en edad de procrear que empleen medidas anticonceptivas eficaces durante el tratamiento. Y se debe recomendar a los hombres que utilicen anticonceptivos de barrera durante y hasta, por lo menos, 90 días después del tratamiento, a menos que exista la seguridad de que la pareja femenina no corre el riesgo de quedarse embarazada (ver apartados Embarazo y lactancia y Reacciones adversas). Se han descrito casos graves de leucopenia, neutropenia, anemia, trombocitopenia, pancitopenia, mielosupresión y anemia aplásica en pacientes tratados con VALCYTE (y con ganciclovir). No debe iniciarse este tratamiento si el recuento absoluto de neutrófilos es menor de 500 células/μl, el recuento de plaquetas es menor de 25.000/μl o el nivel de hemoglobina es menor de 8 g/dl (ver apartados Posología y forma de administración y Reacciones adversas). VALCYTE debe emplearse con precaución en pacientes con citopenia hematológica preexistente, o con antecedentes de citopenia relacionada con la administración de medicamentos, y en pacientes que estén recibiendo radioterapia. Se recomienda vigilar el hemograma completo y las plaquetas durante el tratamiento. En pacientes con alteración renal se debe garantizar un aumento de la monitorización hematológica. Se recomienda considerar el empleo de factores de crecimiento hematopoyético y/o una suspensión de la medicación en pacientes que desarrollen leucopenia, neutropenia, anemia y/o trombocitopenia grave (ver apartados Posología y forma de administración y Reacciones adversas). La biodisponibilidad del ganciclovir tras una dosis única de 900 mg de valganciclovir es del 60% aproximadamente, en comparación con aproximadamente el 6 % tras la administración de 1000 mg de ganciclovir oral (como cápsulas). Una exposición excesiva a ganciclovir puede estar asociada a reacciones adversas con riesgo para la vida. Por consiguiente, se aconseja un estricto seguimiento de las recomendaciones posológicas al inicio de la terapia, cuando se cambie del tratamiento de inducción al de mantenimiento, y en pacientes que cambien de ganciclovir oral a valganciclovir, ya que no se puede reemplazar las cápsulas de ganciclovir por los comprimidos de Valcyte según una relación de uno a uno. Hay que advertir a los pacientes que tomaban con anterioridad cápsulas de ganciclovir del riesgo de sobredosis si ingieren un número de comprimidos de Valcyte mayor del prescrito (ver apartados Posología y forma de administración y Sobredosis). El ajuste posológico para los pacientes con insuficiencia renal debe basarse en el aclaramiento de creatinina (ver apartados Posología y forma de administración). Valcyte comprimidos con cubierta pelicular no debe usarse en pacientes sometidos a hemodiálisis (ver Posología y forma de administración).Se han descrito convulsiones entre pacientes tratados con imipenem-cilastatina y ganciclovir. VALCYTE no debe administrarse al mismo tiempo que imipenem-cilastatina, a menos que los posibles beneficios excedan los riesgos potenciales (ver apartado Interacción con otros medicamentos y otras formas de interacción). Los pacientes tratados con VALCYTE y (a) didanosina, (b) medicamentos con efecto mielosupresor conocido (ej. zidovudina) o (c) sustancias que afecten a la función renal, deben vigilarse estrechamente por si aparecen signos añadidos de toxicidad (ver apartado Interacción con otros medicamentos y otras formas de interacción). El estudio clínico controlado con valganciclovir para el tratamiento profiláctico de la enfermedad por CMV en pacientes trasplantados no incluyó pacientes con trasplante de pulmón e intestino. Por ello, la experiencia en estos pacientes es limitada. VALCYTE polvo para solución oral: Para pacientes con una dieta controlada en sodio, este medicamento contiene 0,188 mg/ml de sodio. Interacción con otros medicamentos y otras formas de interacción: Interacciones farmacológicas con valganciclovir: No se han realizado estudios in vivo de interacción farmacológica con VALCYTE. Debido a que valganciclovir se metaboliza a ganciclovir de manera amplia y rápida, cabe esperar para valganciclovir las mismas interacciones farmacológicas que se asocian con el ganciclovir. Interacciones farmacológicas con ganciclovir: Imipenem-cilastatina: Se han descrito convulsiones en pacientes tratados con ganciclovir e imipenem-cilastatina al mismo tiempo. Estos medicamentos no deben administrarse a la vez, a menos que los posibles beneficios excedan los riesgos potenciales (ver apartado Advertencias y precauciones especiales de empleo). Probenecid: El probenecid, administrado junto con el ganciclovir por vía oral, disminuye significativamente el aclaramiento renal del ganciclovir (20%), aumentando la exposición a este medicamento de manera estadísticamente significativa (40%). Estos cambios son compatibles con un mecanismo de interacción que implica una competición por la secreción tubular renal. Por lo tanto, hay que vigilar con cuidado la posible toxicidad de ganciclovir entre los pacientes que tomen probenecid y VALCYTE. Zidovudina: Cuando se administró zidovudina junto con ganciclovir por vía oral, el AUC de la zidovudina experimentó un incremento pequeño (17%), pero estadísticamente significativo. Asimismo, se advierte una tendencia al descenso de las concentraciones de ganciclovir, cuando se administra simultáneamente zidovudina, aunque sin alcanzar significación estadística. De cualquier manera, puesto que tanto la zidovudina como el ganciclovir pueden inducir neutropenia y anemia, es posible que algunos pacientes no toleren el tratamiento concomitante en dosis plenas (ver apartado Advertencias y precauciones especiales de empleo). Didanosina: Se ha observado que las concentraciones plasmáticas de didanosina aumentan siempre que se administra con ganciclovir (ya sea por vía intravenosa como oral). Cuando se administran dosis orales de ganciclovir de 3 y 6 g/día, se observa un aumento del AUC de didanosina, que varía entre 84 y 124%, y cuando se aplican dosis intravenosas de 5 y 10 mg/kg/día, el incremento observado del AUC de didanosina fluctúa entre 38 y 67%. No se ha observado ninguna modificación clínicamente significativa de las concentraciones de ganciclovir. Hay que vigilar de cerca la posible toxicidad de la didanosina para estos pacientes (ver apartado Advertencias y precauciones especiales de empleo). Micofenolato mofetilo: Considerando los resultados de un estudio de administración de dosis orales únicas recomendadas de micofenolato mofetilo (MMF) y de ganciclovir por vía i.v. y los efectos conocidos de la insuficiencia renal en la farmacocinética de MMF y de ganciclovir, se puede prever que la administración simultánea de ambos medicamentos (que tienen potencial para competir por la secreción tubular renal) determine aumentos del glucurónido fenólico del ácido micofenólico (MPAG) y de la concentración de ganciclovir. La farmacocinética del ácido micofenólico (MPA) apenas se altera y no es necesario ajustar la dosis de MMF. Sin embargo, los pacientes con insuficiencia renal que reciban al mismo tiempo MMF y ganciclovir deberán respetar las recomendaciones posológicas de ganciclovir y requieren una estrecha vigilancia. Ya que el MMF y el ganciclovir pueden causar neutropenia, y leucopenia, se deberá vigilar a los pacientes por si presentaran toxicidad acumulada. Zalcitabina: No se han observado cambios farmacocinéticos clínicamente significativos después de la administración conjunta de ganciclovir y zalcitabina. Tanto valganciclovir como zalcitabina tienen el potencial de producir neuropatía periférica, por lo que se debe vigilar la aparición de esta clase de acontecimientos en los pacientes. Estavudina: Cuando se administran conjuntamente estavudina y ganciclovir por vía oral no se observaron interacciones clínicamente significativas. Trimetoprim: No se observó ninguna interacción farmacocinética clínicamente significativa cuando se administraron conjuntamente trimetoprim y ganciclovir oral. Sin embargo, existe el potencial de incremento de la toxicidad ya que los dos fármacos son mielosupresores, por lo que, ambos fármacos deben usarse de forma concomitante únicamente si los posibles beneficios superan los riesgos. Otros antirretrovirales: A concentraciones clínicamente relevantes, es improbable que se produzca un efecto antagónico o sinérgico de la inhibición del virus de la inmunodeficiencia humana (VIH) en presencia de ganciclovir o del CMV en presencia de fármacos antirretrovirales. No es probable que se produzcan interacciones metabólicas con, por ejemplo, inhibidores de la proteasa o inhibidores de la transcriptasa inversa no nucleosídicos (ITIANNs) debido a la falta de implicación del P450 en el metabolismo tanto del valganciclovir como del ganciclovir. Otras interacciones farmacológicas potenciales: La toxicidad puede verse aumentada cuando valganciclovir se administra junto con, o se da inmediatamente antes o después que, otros fármacos que inhiben la replicación de poblaciones celulares que se dividen rápidamente, tal y como ocurre en la médula ósea, testículos, capas germinales de la piel y mucosa gastrointestinal. Ejemplos de estos tipos de fármacos son dapsona, pentamidina, flucitosina, vincristina, vinblastina, adriamicina, anfotericina B, trimetropim/derivados de sulfamidas, análogos de nucleósidos e hidroxiurea. Debido a que el ganciclovir es excretado a través del riñón, la toxicidad puede verse aumentada cuando valganciclovir se administra junto con fármacos que podrían reducir el aclaramiento renal de ganciclovir y, por lo tanto aumentar su exposición. El aclaramiento renal del ganciclovir puede inhibirse por dos mecanismos: (a) nefrotoxicidad, causada por fármacos como cidofovir y foscarnet, y (b) inhibición competitiva de la secreción tubular activa en el riñón como, por ejemplo, otros análogos de nucleósidos. Por lo tanto, se debe considerar el uso concomitante de todos estos fármacos con valganciclovir sólo si los posibles beneficios superan a los riesgos potenciales (ver apartado Advertencias y precauciones especiales de empleo). Embarazo y lactancia No hay datos del empleo de VALCYTE en mujeres embarazadas. Su metabolito activo, ganciclovir, pasa fácilmente a través de la placenta humana. Existe un riesgo teórico de teratogenicidad en humanos, en base a su mecanismo de acción farmacológico y la toxicidad reproductiva observada en estudios en animales con ganciclovir. VALCYTE no debe emplearse en el embarazo, a menos que los beneficios para la madre superen el riesgo potencial de daño teratogénico para el niño. Las mujeres en edad de procrear deben utilizar medidas anticonceptivas eficaces durante el tratamiento. Se debe aconsejar a los varones que utilicen

CrCl (ml/min)

≥ 6040 – 5925 – 3910 – 24

<10

Dosis de inducción de valganciclovir

900 mg dos veces al día450 mg dos veces al día450 mg una vez al día225 mg una vez al día200 mg tres veces a la semana tras diálisis

Dosis de mantenimiento/Dosis de prevención de valganciclovir

900 mg una vez al día450 mg una vez al día225 mg una vez al día125 mg una vez al día100 mg tres veces a la semana tras diálisis

CrCl (ml/min)

≥ 6040 – 5925 – 3910 – 24

Dosis de inducción de valganciclovir

900 mg (2 comprimidos) dos veces al día450 mg (1 comprimido) dos veces al día450 mg (1 comprimido) una vez al día450 mg (1 comprimido) cada 2 días

Dosis de mantenimiento/Dosis de prevención de valganciclovir

900 mg (2 comprimidos) una vez al día450 mg (1 comprimido) una vez al día450 mg (1 comprimido) cada 2 días450 mg (1 comprimido) dos veces por semana

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medidas anticonceptivas de barrera durante y hasta, por lo menos, 90 días después del tratamiento con VALCYTE, a menos que exista la seguridad de que la pareja femenina no corra el riesgo de quedarse embarazada. Se desconoce si el ganciclovir se excreta en la leche materna pero no se puede descartar esta posibilidad, con las reacciones adversas graves consiguientes para el bebé lactante. Por eso, debe interrumpirse la lactancia (ver apartado Contraindicaciones). Efectos sobre la capacidad para conducir y utilizar máquinas: No se han realizado estudios de los efectos sobre la capacidad para conducir y utilizar máquinas. El uso de VALCYTE y/o de ganciclovir se ha asociado con convulsiones, sedación, mareos, ataxia y/o confusión. Si aparece cualquiera de estas reacciones, podrían alterar las tareas que exigen un estado de alerta, como la capacidad para conducir vehículos y utilizar máquinas. Reacciones adversas: El valganciclovir es un profármaco del ganciclovir, que se metaboliza de manera rápida y extensa a ganciclovir después de su administración oral. Valganciclovir debería asociarse con las mismas reacciones adversas conocidas para el ganciclovir. Todas las reacciones adversas observadas en los estudios clínicos con valganciclovir se habían observado antes con ganciclovir. Las reacciones adversas más comunes comunicadas tras la administración de valganciclovir son neutropenia, anemia y diarrea. Valganciclovir, se asocia a un mayor riesgo de diarrea comparado con ganciclovir i.v. Además, valganciclovir se asocia con un riesgo más alto de neutropenia y leucopenia comparado con ganciclovir oral. Se observa con más frecuencia neutropenia grave (< 500 recuento total de neutrófilos/μl) en pacientes con retinitis por CMV en tratamiento con valganciclovir que en pacientes con trasplante de órgano sólido recibiendo valganciclovir. En la siguiente tabla se detalla la frecuencia de las reacciones adversas notificadas en los ensayos clínicos con valganciclovir, ganciclovir oral, o ganciclovir intravenoso. Las reacciones adversas reflejadas en la tabla se comunicaron en ensayos clínicos para el tratamiento de inducción y mantenimiento de la retinitis por CMV en pacientes con SIDA, o para la profilaxis de la enfermedad por CMV en pacientes con trasplante de corazón, riñón o hígado. El término (grave) que aparece en paréntesis en la tabla indica que la reacción adversa se ha comunicado en pacientes tanto de intensidad leve/moderada como intensidad grave/amenazante para la vida en esa frecuencia específica. Las reacciones adversas se enumeran en orden decreciente de gravedad dentro de cada intervalo de frecuencia.

Se puede asociar la trombocitopenia grave con amenaza de la vida por una hemorragia. Sobredosis: Experiencia con sobredosis de valganciclovir. Un adulto que recibió durante varios días dosis 10 veces mayores de las recomendadas para su grado de insuficiencia renal (disminución del aclaramiento de creatinina) sufrió una mielosupresión mortal (aplasia medular). Cabe esperar que la sobredosis de valganciclovir pueda aumentar también la toxicidad renal de este compuesto (ver apartados Posología y forma de administración y Advertencias y precauciones especiales de empleo). La hemodiálisis y la hidratación pueden resultar beneficiosos para reducir los niveles plasmáticos de los pacientes que reciben sobredosis de valganciclovir. Experiencia con sobredosis de ganciclovir por vía intravenosa: Se han recibido notificaciones de sobredosis de ganciclovir por vía intravenosa sucedidas en ensayos clínicos y durante la comercialización de este medicamento. En algunos de estos casos no se observó ningún tipo de acontecimiento adverso. La mayoría de los enfermos presentaron uno o más de los siguientes acontecimientos adversos: Toxicidad hematológica: pancitopenia, mielosupresión, aplasia medular, leucopenia, neutropenia, granulocitopenia. Toxicidad hepática: hepatitis, trastornos de la función hepática. Toxicidad renal: empeoramiento de la hematuria de un paciente con alteraciones previas de la función renal, insuficiencia renal aguda, elevación de la creatinina. Toxicidad digestiva: dolor abdominal, diarrea, vómitos. Neurotoxicidad: temblor generalizado, convulsiones. DATOS FARMACÉUTICOS: Lista de excipientes: VALCYTE polvo para solución oral: povidona, ácido fumárico, benzoato sódico (E211), sacarina sódica, manitol. Sabor Tutti-frutti: maltodextrina (maíz), propilenglicol, goma arábiga E414 y sustancias naturales que dan sabor principalmente de plátano, piña y melocotón. VALCYTE comprimidos con cubierta pelicular: Núcleo de los comprimidos: Povidona K30, Crospovidona, Celulosa microcristalina, Ácido esteárico. Recubrimiento pelicular de los comprimidos: Opadry Rosa 15B24005 que contiene: Hipromellosa, Dióxido de titanio (E171), Macrogol 400, Óxido de hierro rojo (E172), Polisorbato 80. Incompatibilidades: No aplicable. Periodo de validez: VALCYTE polvo para solución oral: Polvo para solución oral: 2 años. Solución reconstituida: 49 días. Conservar en nevera (2ºC - 8ºC). VALCYTE comprimidos con cubierta pelicular: 3 años. Precauciones especiales de conservación: Este medicamento no requiere condiciones especiales de conservación. Para las condiciones de conservación del medicamento reconstituido, ver apartado Periodo de validez. Naturaleza y contenido del envase: VALCYTE polvo para solución oral: La caja contiene un frasco de cristal ámbar de 100 ml, con un tapón de plástico a prueba de niños, un adaptador de plástico para el frasco y una bolsa de plástico que contiene 2 dispensadores orales de plástico graduados hasta 500 mg, con graduaciones de 25 mg. Cada frasco contiene 12 g de polvo para solución oral. Cuando se reconstituye, el volumen de la solución es 100 ml, proporcionando el volumen mínimo utilizable, 88 ml. VALCYTE comprimidos con cubierta pelicular: Frascos de polietileno de alta densidad (HDPE), con cierre de polipropileno a prueba de niños y algodón. 60 comprimidos. Precauciones especiales de eliminación y otras manipulaciones: VALCYTE polvo para solución oral: debe manipularse con precaución tanto el polvo como la solución reconstituida, ya que es considerado un potencial agente teratógeno y carcinógeno en humanos (ver apartado Advertencias y precauciones especiales de empleo). Evite la inhalación y el contacto directo del polvo y de la solución en piel y membranas mucosas. Si ocurriese tal contacto, lávese a fondo con jabón y agua. Si el polvo o la solución entran en los ojos, aclare los ojos a fondo con agua. Se recomienda que VALCYTE polvo para solución oral sea reconstituida por un farmacéutico antes de dispensarse al paciente. Preparación de la solución: 1. Medir 91 ml de agua en una probeta graduada. 2. Quitar el tapón a prueba de niños, añadir el agua en el frasco y cierre el frasco con el tapón a prueba de niños. Agitar el frasco cerrado hasta que se disuelva todo el polvo formando una solución clara, de incolora a parda. 3. Quitar el tapón a prueba de niños y poner el adaptador en el cuello del frasco. 4.Cerrar bien fuerte el frasco con el tapón a prueba de niños. Esto asegurará el asentamiento apropiado del adaptador al frasco y la función del tapón a prueba de niños. 5. Escribir la fecha de caducidad de la solución reconstituida en la etiqueta del frasco (ver apartado Periodo de validez ). La eliminación del medicamento no utilizado y de todos los materiales que hayan estado en contacto con él, se realizará de acuerdo con la normativa local. TITULAR DE LA AUTORIZACIÓN DE COMERCIALIZACIÓN: Roche Farma, S.A. Eucalipto, no 33. 28016 Madrid. NÚMERO(S) DE AUTORIZACIÓN DE COMERCIALIZACIÓN: VALCYTE polvo para solución oral: Número de registro: 69.760 VALCYTE comprimidos con cubierta pelicular: Número de registro: 64.829. FECHA DE LA PRIMERA AUTORIZACIÓN/RENOVACIÓN DE LA AUTORIZACIÓN. VALCYTE polvo para solución oral: Abril 2008. VALCYTE comprimidos con cubierta pelicular: Fecha de la primera autorización: 5 de marzo de 2002. Renovación de la autorización: 12 de abril de 2007. FECHA DE LA REVISIÓN DEL TEXTO: Abril 2008. PRECIOS AUTORIZADOS: Valcyte, 50 mg polvo para solución oral. P.V.L.: 258,18 €. P.V.P.: 304,09 €. P.V.P (IVA): 316,25 €. Valcyte 450 mg (60 comprimidos). P.V.L.: 1.267 €. P.V.P (IVA): 1.364,82 €. CONDICIONES DE DISPENSACIÓN: Valcyte polvo para solución oral: Especialidad farmacéutica de uso hospitalario. Valcyte comprimidos con cubierta pelicular: Especialidad de diagnóstico hospitalario. Para cualquier información adicional: Roche Farma, Tel.: 91 324 81 00

Sistema corporal Muy frecuentes Frecuentes Poco frecuentes Raras (≥ 1/10) (≥ 1/100, < 1/10) (≥ 1/1.000, < 1/100) (≥ 1/10.000, < 1/1.000) Solo para Valcyte POSExploraciones complementarias aumento de creatinina en sangre, pérdida de peso Trastornos cardiacos arritmias Trastornos de la sangre neutropenia (grave), Pancitopenia (grave), mielosupresión anemia aplásicay del sistema linfático anemia leucopenia (grave), anemia (grave), trombocitopenia (grave) Trastornos del sistema nervioso convulsiones, neuropatía temblores periférica, insomnio, hipoestesia, parestesia, mareos (sin vértigo), disgeusia (trastorno del gusto), dolor de cabeza Trastornos oculares desprendimiento de retina, visión anormal, edema macular, dolor ocular, conjuntivitis moscas flotantes Trastornos del oído y del laberinto dolor de oídos sordera Trastornos respiratorios, torácicos disnea tosy mediastínicos Trastornos gastrointestinales diarrea náuseas, vómitos, dolor pancreatitis, abdominal, dolor abdominal distensión abdominal, superior, estreñimiento, disfagia, ulceraciones orales dispepsia, flatulencia Trastornos renales y urinarios disfunción renal, disminución del Insuficiencia renal, hematuria aclaramiento de la creatinina renal Trastornos de la piel y del dermatitis, sudores alopecia, urticaria,tejido subcutáneo nocturnos, prurito sequedad de la piel Trastornos muscoloesqueléticos dolor de espalda, mialgia, y del tejido conjuntivo y óseo artralgia, calambres musculares(para Valcyte comprimidos) Trastornos del metabolismo anorexia, pérdida del apetitoy de la nutrición Infecciones e infestaciones sepsis (bacteriemia, viremia), celulitis, infección del tracto urinario, candidiasis oral Trastornos vasculares hipotensión Trastornos generales y fatiga, fiebre, rigidez, dolor, alteraciones en el lugar dolor torácico, malestar, astenia, de administración escalofríos (solo valcyte comprimidos) Trastornos del sistema inmunológico reacción anafilácticaTrastornos hepatobiliares función hepática anormal (grave), aumento de la alanina aumento de la fosfatasa alcalina aminotransferasa en sangre, aumento del aspartato aminotransferasa Trastornos del aparato reproductor Infertilidad masculinay de la mama Trastornos psiquiátricos depresión, ansiedad, confusión, Alteración psicótica, pensamientos perturbados agitación, alucinaciones

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1. NOMBRE DEL MEDICAMENTO CellCept 500 mg, comprimidos; CellCept 250 mg, cápsulas; CellCept, 500 mg, polvo paraconcentrado para solución para perfusión; CellCept 1 g/5 ml polvo para suspensión oral. 2. COMPOSICIÓN CUALITATIVA YCUANTITATIVA Cada comprimido contiene 500 mg de micofenolato mofetilo. Cada cápsula contiene 250 mg de micofenolatomofetilo. Cada vial contiene el equivalente a 500 mg de micofenolato mofetilo (clorhidrato). Cada frasco contiene 35 g demicofenolato mofetilo en 110 g de polvo para suspensión oral. Excipientes: Para la lista completa, ver sección 6.1. 3. FORMAFARMACÉUTICA Comprimidos recubiertos con película Comprimidos CellCept: oblongos, de color azul espliego, con el grabado“CellCept 500” en una cara y el “logotipo de la Empresa” en la otra. Cápsulas duras Cápsulas CellCept: oblongas, de colorazul/marrón, con la inscripción “CellCept 250” en la mitad superior y el “logotipo de la Compañía” en la mitad inferior. Polvo paraconcentrado para solución para perfusión. CellCept 500 mg polvo para concentrado para solución para perfusión debe serreconstituido y posteriormente diluido con una solución para perfusión intravenosa de glucosa al 5 %, antes de la administraciónal paciente (ver sección 6.6). Polvo para suspensión oral. CellCept 1 g/5 ml polvo para suspensión oral: cada frasco contiene 35 gde micofenolato mofetilo en 110 g de polvo para suspensión oral. 5 ml de la suspensión reconstituida contiene 1 g de micofenolatomofetilo. 4. DATOS CLÍNICOS 4.1. Indicaciones terapéuticas CellCept, en combinación con ciclosporina y corticosteroides, estáindicado para la pro�laxis del rechazo agudo de trasplante en pacientes sometidos a trasplante alogénico renal, cardíaco o hepático.4.2 Posología y forma de administración El tratamiento con CellCept debe ser iniciado y mantenido por especialistasdebidamente cuali�cados en trasplantes. ADVERTENCIA: LA SOLUCIÓN INTRAVENOSA DE CELLCEPT NUNCA DEBE SERADMINISTRADA MEDIANTE INYECCIÓN INTRAVENOSA RÁPIDA O EN BOLUS. CellCept 500 mg polvo para concentrado parasolución para perfusión es una forma farmacéutica alternativa a las formas orales de CellCept (cápsulas, comprimidos y polvopara suspensión oral) que puede ser administrada durante 14 días. La dosis inicial de CellCept 500 mg polvo para concentradopara solución para perfusión debe administrarse, dentro de las 24 horas siguientes al trasplante.Tras la reconstitución hasta unaconcentración de 6 mg/mL, CellCept 500 mg polvo para concentrado para solución para perfusión se debe administrar medianteperfusión intravenosa lenta en un período superior a 2 horas, bien en vena periférica o en vena central (ver sección 6.6). Nota Sies preciso, CellCept 1 g/5 ml polvo para suspensión oral se puede administrar a través de un tubo nasogástrico con un tamañomínimo de 8º franceses (diámetro interior mínimo de 1,7 mm). Uso en trasplante renal: Adultos: el inicio de la administración deCellCept por vía oral debe realizarse en las 72 horas siguientes al trasplante. La dosis recomendada en trasplantados renales esde 1 g administrado dos veces al día (dosis diaria total = 2 g). Niños y adolescentes (entre 2 y 18 años): la dosis recomendada demicofenolato mofetilo es de 600 mg/m2, administrada dos veces al día por vía oral (hasta un máximo de 2 g diarios). Loscomprimidos de CellCept deben prescribirse únicamente a pacientes con una super�cie corporal mayor de 1,5 m2, deben recibiruna dosis de 1 g dos veces al día (dosis diaria total = 2 g). Debido a que algunas reacciones adversas ocurren con una mayorfrecuencia en este grupo de edad (ver sección 4.8), en comparación con los adultos, es posible que sea necesario efectuarreducciones de dosis temporales o interrupción del tratamiento; esto deberá tener en cuenta factores clínicos relevantes incluyendola gravedad del evento. Niños (< 2 años): existen datos limitados de seguridad y e�cacia en niños con una edad inferior a los2 años. Estos son insu�cientes para realizar recomendaciones posológicas y por consiguiente, no se recomienda su uso en estegrupo de edad. Uso en trasplante cardíaco: Adultos: el inicio de la administración de CellCept por vía oral debe realizarse en los5 días siguientes al trasplante. La dosis recomendada en los pacientes sometidos a trasplante cardíaco es de 1,5 g administradados veces al día (dosis diaria total = 3 g). Niños: No hay datos disponibles en pacientes pediátricos con trasplante cardíaco. Usoen trasplante hepático: Adultos: se debe administrar CellCept IV durante los 4 días siguientes al trasplante hepático, posteriormentese comenzará la administración de CellCept oral, tan pronto como ésta sea tolerada. La dosis oral recomendada en los pacientessometidos a trasplante hepático es de 1,5 g administrados dos veces al día (dosis total diaria = 3 g).Niños: No hay datos disponiblesen pacientes pediátricos con trasplante hepático. Uso en ancianos (≥ 65 años): la dosis recomendada en ancianos es de 1 gadministrado dos veces al día en el trasplante renal y 1,5 g dos veces al día en los trasplantes cardíaco y hepático. Uso en pacientescon insu�ciencia renal: en pacientes sometidos a trasplante renal con insu�ciencia renal crónica grave (�ltración glomerular< 25 mL·min-1·1,73 m-2), deben evitarse dosis superiores a 1 g dos veces al día fuera del período inmediatamente posterior altrasplante. Se debe observar cuidadosamente a estos pacientes. No son necesarios ajustes posológicos en pacientes con retrasofuncional del riñón trasplantado en el postoperatorio (ver sección 5.2).No existen datos sobre los pacientes sometidos a trasplantecardíaco o hepático con insu�ciencia renal crónica grave. Uso en pacientes con insu�ciencia hepática grave: los pacientes sometidosa trasplante renal con enfermedad grave del parénquima hepático, no precisan ajuste de dosis. No existen datos sobre los pacientessometidos a trasplante cardíaco con enfermedad grave del parénquima hepático. Tratamiento durante episodios de rechazo: elácido micofenólico (MPA) es el metabolito activo del micofenolato mofetilo. El rechazo del riñón trasplantado no provoca cambiosen la farmacocinética del MPA; no es necesario reducir la dosis o interrumpir el tratamiento con CellCept. No hay fundamentospara ajustar la dosis de CellCept tras el rechazo del corazón transplantado. No se dispone de datos farmacocinéticos durante elrechazo del hígado trasplantado.4.3 Contraindicaciones Se han descrito reacciones de hipersensibilidad a CellCept (ver sección4.8). Por consiguiente, este medicamento está contraindicado en pacientes con hipersensibilidad al micofenolato mofetilo o alácido micofenólico. CellCept está contraindicado en mujeres en periodo de lactancia (ver el sección 4.6). Para información sobresu uso durante el embarazo así como las medidas contraceptivas a adoptar ver sección 4.6. 4.4 Advertencias y precaucionesespeciales de empleo Los pacientes que reciben CellCept como parte de un tratamiento inmunosupresor en combinación conotros medicamentos, presentan un mayor riesgo de desarrollar linfomas y otros tumores malignos, en especial de la piel (versección 4.8). El riesgo parece estar relacionado con la intensidad y la duración de la inmunosupresión más que con el uso de unfármaco determinado. Como norma general para minimizar el riesgo de cáncer de piel, se debe limitar la exposición a la luz solary a la luz UV mediante el uso de ropa protectora y el empleo de pantalla solar con factor de protección alto. Se debe indicar a lospacientes que reciben tratamiento con CellCept que comuniquen inmediatamente cualquier evidencia de infección, contusionesno esperadas, hemorragias o cualquier otra manifestación de depresión de la médula ósea. La supresión excesiva del sistemainmunitario aumenta la vulnerabilidad a las infecciones, incluyendo infecciones oportunistas, infecciones mortales y sepsis (versección 4.8). En pacientes tratados con Cellcept se han noti�cado casos, alguno de ellos mortales, de Leucoencefalopatía MultifocalProgresiva (LMP). En general, los casos noti�cados presentaban factores de riesgo para la LMP, como tratamiento inmunosupresory función inmune deteriorada. En pacientes inmunodeprimidos que presenten síntomas neurológicos, los clínicos deben tener encuenta la LMP a la hora de realizar un diagnostico diferencial, y estaría indicado desde un punto de vista clínico realizar unaconsulta con el neurólogo. En los pacientes que desarrollen LPM, se debe considerar reducir la inmunosupresión total. Sin embargo,en pacientes trasplantados, reducir la inmunosupresión puede suponer un riesgo de rechazo del injerto. Se debe monitorizar a lospacientes en tratamiento con CellCept debido a la neutropenia, la cual podría estar relacionada con el propio CellCept, conmedicamentos concomitantes, con infecciones virales, o con la combinación de estas causas. En los pacientes tratados conCellCept se deben realizar hemogramas completos una vez por semana durante el primer mes, dos veces al mes durante losmeses segundo y tercero de tratamiento y, a continuación, una vez al mes durante todo el resto del primer año. Se deberíainterrumpir o �nalizar el tratamiento con CellCept si se desarrollase la neutropenia (recuento absoluto de neutró�los< 1,3 x 10³/microlitro). Se han reportado casos de aplasia pura de células rojas (APCR) en pacientes tratados con Cellcept encombinación con otros inmunosupresores. El mecanismo de inducción de APCR por parte de micofenolato mofetilo es desconocido;así mismo, la contribución relativa de otros inmunosupresores y su combinación en un régimen inmunosupresor es tambiéndesconocida. En algunos casos la APCR es reversible con disminución de dosis o cese del tratamiento con Cellcept. Sin embargo,en los pacientes trasplantados la reducción de inmunosupresión puede aumentar el riesgo de rechazo. Se debe informar a lospacientes que durante el tratamiento con CellCept las vacunaciones pueden ser menos e�caces y que se debe evitar el empleode vacunas atenuadas de organismos vivos (ver sección 4.5).Se debe considerar la vacunación contra la gripe. El médico deberáobservar las directrices nacionales para la vacunación contra la gripe. Se ha relacionado CellCept con un aumento en la incidenciade eventos adversos en el aparato digestivo, entre los que se incluyen casos poco frecuentes de ulceraciones en el tractogastrointestinal, hemorragias y perforaciones. Por este motivo CellCept debe administrarse con precaución en pacientes conenfermedad activa grave del aparato digestivo. CellCept es un inhibidor de la inosin monofosfato deshidrogenasa (IMPDH). Por loque, en teoría, debe evitarse su empleo en pacientes con de�ciencia hereditaria rara de la hipoxantina-guanina fosforribosiltransferasa (HGPRT) como es el caso de los Síndromes de Lesch-Nyhan y Kelley-Seegmiller.No se recomienda administrar CellCeptal mismo tiempo que azatioprina, ya que su administración concomitante no se ha estudiado. Teniendo en cuenta la reducciónsigni�cativa del AUC del MPA que produce la colestiramina, la administración concomitante de CellCept y medicamentos queinter�eran en la recirculación enterohepática debe llevarse a cabo con precaución, dada la posibilidad de que disminuya la e�caciade CellCept. No se ha establecido el balance bene�cio-riesgo de micofenolato mofetilo en combinación con tacrolimus o sirolimus(ver también sección 4.5). Se han reportado casos de aplasia pura de células rojas (APCR) en pacientes tratados con Cellcept encombinación con otros agentes inmunosupresores. El mecanismo por el que micofenolato mofetilo induce APCR se desconoce;la contribución relativa de otros inmunosupresores y sus combinaciones en un régimen inmunosupresor es también desconocida.En algunos casos APCR fue reversible con reducción de dosis o supresión de Cellcept. Sin embargo, en pacientes trasplantadosreducir la inmunosupresión puede aumentar el riesgo de rechazo.4.5 Interacción con otros medicamentos y otras formas deinteracción Los estudios de interacciones se han realizado sólo en adultos.Aciclovir: se observaron concentraciones plasmáticasde aciclovir más altas cuando se administra con micofenolato mofetilo que cuando se administra aciclovir solo. Los cambios enla farmacocinética del MPAG (el glucurónido fenólico del MPA) fueron mínimos (aumento del MPAG entorno al 8 %) y no seconsideran clínicamente signi�cativos. Dado que las concentraciones plasmáticas de MPAG y aciclovir aumentan cuando estádeteriorada la función renal, existe la posibilidad de que micofenolato mofetilo y aciclovir, o sus profármacos, ej. valaciclovircompitan en la secreción tubular y se eleve aún más la concentración de ambas sustancias.Antiácidos con hidróxidos de magnesioy aluminio: la absorción del micofenolato mofetilo disminuyó tras su administración con antiácidos. Colestiramina: tras laadministración de una dosis única de 1,5 g de micofenolato mofetilo a sujetos sanos tratados previamente con 4 g de colestiramina,tres veces al día, durante 4 días, se observó la disminución del AUC del MPA (ver secciones 4.4, y 5.2). Se deberá tener precaucióncuando se administren conjuntamente, debido a su potencial para reducir la e�cacia de CellCept. Medicamentos que inter�erencon la circulación enterohepática: se debe tener precaución cuando se empleen medicamentos que inter�eran con la circulaciónenterohepática debido a su potencial para reducir la e�cacia de CellCept. Ciclosporina A: la farmacocinética de la ciclosporina A

(CsA) no experimenta variaciones debidas a micofenolato mofetilo. Sin embargo, si se cesa la administración concomitante deciclosporina, es previsible un aumento del AUC del MPA entorno al 30%. Ganciclovir: teniendo en cuenta los resultados de unestudio de administración de dosis única a las dosis recomendadas de micofenolato oral y ganciclovir intravenoso, así como losconocidos efectos de la insu�ciencia renal en la farmacocinética del CellCept (ver sección 4.2) y del ganciclovir, se prevé que laadministración conjunta de estos fármacos (que compiten por los mismos mecanismos de la secreción tubular renal) de lugar aun aumento de la concentración del MPAG y del ganciclovir. Como no hay indicios de que se produzca una alteración sustancialde la farmacocinética del MPA no es necesario ajustar la dosis de CellCept. Se debería considerar las recomendaciones de dosisde ganciclovir, así como llevar a cabo una estrecha vigilancia en aquellos pacientes con insu�ciencia renal y que estén siendotratados con CellCept y ganciclovir simultáneamente o sus profármacos, ej. valganciclovir.Anticonceptivos orales:la farmacocinéticay la farmacodinamia de los anticonceptivos orales no se vieron modi�cadas por la administración simultánea de CellCept (verademás sección 5.2). Rifampicina: En pacientes no tratados con ciclosporina, la administración concomitante de Cellcept yrifampicina dió lugar a una disminución en la exposición al MPA del 18% al 70% (AUC 0-12h). Por lo tanto, se recomienda vigilarlos niveles de exposición al MPA y ajustar las dosis de CellCept en consecuencia para mantener la e�cacia clínica cuando seadministra rifampicina de forma concomitante. Sirolimus: en pacientes sometidos a trasplante renal, la administración concomitantede Cellcept con ciclosporina redujo la exposición al MPA en un 30-50% en comparación con los pacientes que habían recibido lacombinación de sirolimus y dosis similares de Cellcept (ver además sección 4.4). Sevelamer: la administración concomitante deCellcept con sevelamer disminuyó la Cmax del MPA y del AUC 0-12 en un 30% y 25%, respectivamente, sin consecuenciasclínicas (ej: rechazo del injerto). Sin embargo, se recomendó administrar Cellcept al menos una hora antes o tres horas despuésdel uso de sevelamer para minimizar el impacto sobre la absorción del MPA. .Con respecto a los ligantes de fosfasto solo existendatos de Cellcept con sevelamer. Trimetoprim/sulfametoxazol: no se observó ningún efecto sobre la biodisponibilidad del MPA.Nor�oxacino y metronidazol: no se ha observado interacción signi�cativa en la administración concomitante separada de Cellceptcon nor�oxacina o con metronidazol en voluntarios sanos. Sin embargo, nor�oxacina y metronidazol combinados redujeron laexposición al MPA en aproximadamente un 30% tras una dosis única de Cellcept Tacrolimus:En los pacientes sometidos a trasplantehepático que comenzaron con Cellcept y tacrolimus, el AUC y la Cmáx del MPA no se vieron afectados de forma signi�cativa porla administración conjunta con tacrolimus. Por el contrario, hubo un aumento de aproximadamente un 20% en el AUC de tacrolimuscuando se administraron dosis múltiples de Cellcept (1,5 g dos veces al día) a pacientes tratados con tacrolimus. Sin embargo,en pacientes con transplante renal, la concentración de tacrolimus no pareció verse alterada por Cellcept (ver además sección4.4). Otras interacciones: la administración conjunta de probenecid y micofenolato mofetilo en mono eleva al triple el valor delAUC del MPAG. En consecuencia, otras sustancias con secreción tubular renal pueden competir con el MPAG y provocar así unaumento de las concentraciones plasmáticas del MPAG o de la otra sustancia sujeta a secreción tubular. Vacunas de organismosvivos: las vacunas de organismos vivos no deben administrarse a pacientes con una respuesta inmune deteriorada. La respuestade anticuerpos a otras vacunas puede verse disminuida. (ver también sección 4.4).4.6 Embarazo y lactancia Se recomienda noiniciar tratamiento con CellCept hasta disponer de una prueba de embarazo negativa. Se debe utilizar un tratamiento anticonceptivoefectivo antes de comenzar el tratamiento, a lo largo del mismo, y durante las seis semanas siguientes a la terminación deltratamiento con CellCept (ver sección 4.5). Debe indicarse a los pacientes que consulten inmediatamente a su médico en caso dequedar embarazadas. No se recomienda el uso de CellCept durante el embarazo, quedando reservado solo para aquellos casosen los que no haya disponible un tratamiento alternativo más adecuado. CellCept solo se debería usar durante el embarazo si elbene�cio para la madre supera el riesgo potencial para el feto. Se dispone de datos limitados del uso de CellCept en mujeresembarazadas. No obstante, se han noti�cado casos de malformaciones congénitas en hijos de pacientes tratados durante elembarazo con Cellcept en combinación con otros inmunosupresores, incluyendo malformaciones en oidos, p.ej. carencia del oídoexterno/medio o con anomalía en la formación.Se han noti�cado casos de abortos espontáneos en pacientes tratados conCellcept.Los estudios en animales han mostrado toxicidad reproductiva (ver sección 5.3). En ratas lactantes se ha demostradoque el micofenolato mofetilo se elimina en la leche. No se sabe si esta sustancia se elimina en la leche humana. CellCept estácontraindicado en mujeres durante el periodo de lactancia, debido al riesgo potencial de reacciones adversas graves al micofenolatomofetilo en niños lactantes (ver sección 4.3). 4.7 Efectos sobre la capacidad para conducir y utilizar máquinas No se hanrealizado estudios sobre la capacidad para conducir y utilizar máquinas. El per�l farmacodinámico y las reacciones adversasdescritas indican que es improbable tal efecto. 4.8 Reacciones adversas Entre las siguientes reacciones adversas se incluyenlas reacciones adversas ocurridas durante los ensayos clínicos: Las principales reacciones adversas, asociadas a la administraciónde CellCept en combinación con ciclosporina y corticosteroides, consisten en diarrea, leucopenia, sepsis y vómitos; se hanobservado, además, indicios de una frecuencia más alta de ciertos tipos de infección (ver sección 4.4). Neoplasias malignos: Lospacientes bajo tratamiento inmunosupresor con asociaciones de medicamentos, que incluyen CellCept tienen mayor riesgo dedesarrollar linfomas y otras neoplasias malignas, principalmente en la piel (ver sección 4.4). Se desarrollaron enfermedadeslinfoproliferativas o linfomas en el 0,6 % de los pacientes que recibían CellCept (2 g ó 3 g diarios) en combinación con otrosinmunosupresores, en ensayos clínicos controlados de pacientes con transplante renal (datos con 2 g), cardíaco y hepático, a losque se les hizo seguimiento durante por lo menos 1 año. Se observó cáncer de piel, excluyendo al melanoma, en el 3,6 % de lospacientes; se observaron otros tipos de neoplasias malignas en el 1,1 % de los pacientes. Los datos de seguridad a tres años enpacientes con transplante renal y cardíaco no mostraron ningún cambio inesperado en la incidencia de neoplasias malignas encomparación con los datos a 1 año. El seguimiento de los pacientes con transplante hepático fue de al menos 1 año pero inferiora 3 años. Infecciones oportunistas: Todos los pacientes transplantados tienen mayor riesgo de padecer infecciones oportunistas,este riesgo aumenta con la carga inmunosupresora total (ver sección 4.4). Las infecciones oportunistas más comunes en pacientestratados con CellCept (2 g ó 3 g diarios) juntos con otros inmunosupresores, detectadas en los ensayos clínicos controlados depacientes con transplante renal (datos con 2 g), cardíaco y hepático, a los que se les hizo un seguimiento de al menos 1 año,fueron candida mucocutánea, viremia/síndrome por CMV y Herpes simplex. La proporción de pacientes con viremia/síndrome porCMV fue del 13,5 %. Niños y adolescentes (entre 2 y 18 años): En un ensayo clínico, que incluía a 92 pacientes pediátricos deedades comprendidas entre los 2 y los 18 años, tratados dos veces al día con 600 mg/m2 de micofenolato mofetilo administradopor vía oral, el tipo y la frecuencia de las reacciones adversas fueron, por lo general, similares a aquellas observadas en pacientesadultos tratados con 1 g de CellCept dos veces al día. No obstante, las siguientes reacciones adversas relacionadas con eltratamiento fueron más frecuentes en la población pediátrica, particularmente en niños menores de 6 años de edad, que en la deadultos: diarreas, sepsis, leucopenia, anemia e infección. Pacientes ancianos (≥ 65 años): Los pacientes ancianos (≥ 65 años) engeneral pueden presentar mayor riesgo de reacciones adversas debido a la inmunosupresión. Los pacientes ancianos, que recibenCellCept como parte de un régimen inmunosupresor en combinación, podrían tener mayor riesgo de padecer ciertas infecciones(incluyendo la enfermedad hística invasiva por citomegalovirus), posibles hemorragias gastrointestinales y edema pulmonar, encomparación con individuos jóvenes. Otras reacciones adversas: En la siguiente tabla se indican las reacciones adversas,probablemente o posiblemente relacionadas con CellCept, noti�cadas en ≥1/10 y en ≥1/100 a <1/10 de los pacientes tratadoscon CellCept en los ensayos clínicos controlados de pacientes con transplante renal (datos con 2 g), cardíaco y hepático.Reacciones Adversas, Probablemente o Posiblemente Relacionadas con CellCept, Noti�cadas en Pacientes Tratados conCellCept en los Ensayos Clínicos en Transplante Renal, Cardíaco y Hepático cuando se Usa en Asociación con Ciclosporinay Corticosteroides Dentro de la clasi�cación por órganos y sistemas, las reacciones adversas se presentan bajo el encabezamientode frecuencia, usando las siguientes categorías: muy frecuentes (≥ 1/10); frecuentes (≥ 1/100 < 1/10); poco frecuentes (≥ 1/1.000< 1/100); raras (≥ 1/10.000 ≤1/1.000); muy raras (≤1/10.000), no conocidas (no se puede estimar a partir de los datos disponibles).Las reacciones adversas se presentan en orden decreciente de gravedad dentro de cada frecuencia.

Clasi�cación por órgano y sistema Reacciones adversas al fármaco Infecciones e infestaciones Muy frecuentes Sepsis, candidiasis gastrointestinal, infección del tracto urinario, herpes simplex, herpes zoster Frecuentes Neumonía, síndrome gripal, infección del tracto respiratorio, moniliasis respiratoria, infección gastrointestinal, candidiasis,

gastroenteritis, infección, bronquitis, faringitis, sinusitis, dermatitis micótica, candidiasis en piel, candidiasis vaginal, rinitis Neoplasias benignas, malignas y no especi�cadas (incl quistes y pólipos) Muy frecuentes - Frecuentes Cáncer cutáneo, tumor benigno de piel Trastorno de la sangre y del sistema linfático Muy frecuentes Leucopenia, trombocitopenia, anemia Frecuentes Pancitopenia, leucocitosis Trastornos del metabolismo y de la nutrición Muy frecuentes - Frecuentes Acidosis, hiperpotasemia, hipopotasemia, hiperglicemia,hipomagnesemia, hipocalcemia, hipercolesterolemia, hiperlipide-

mia, hipofosfatemia, hiperuricemia, gota, anorexia Trastornos psiquiátricos Muy frecuentes - Frecuentes Agitación,confusión, depresión, ansiedad, alteración del pensamiento, insomnio

Trastornos del sistema nervioso Muy frecuentes - Frecuentes Convulsión, hipertonía, temblor, somnolencia, síndrome miasténico, mareos, dolor de cabeza, parestesia, disgeusia Trastornos cardíacos Muy frecuentes - Frecuentes Taquicardia

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Los siguientes efectos adversos incluyen las reacciones adversas ocurridas durante la experiencia posterior a lacomercialización: Los tipos de reacciones adversas, noti�cadas tras la comercialización de CellCept, son similares a lasobservadas en los ensayos controlados en transplante renal, cardíaco y hepático. A continuación se describen reaccionesadversas al fármaco adicionales, noti�cadas tras la comercialización, con las correspondientes frecuencias si se conocen,dentro de paréntesis. Aparato digestivo: colitis incluyen colitis por citomegalovirus, (≥1/100 <1/10), pancreatitis (≥1/100<1/10), y atro�a de las vellosidades intestinales. Alteraciones relacionadas con la inmunosupresión: Se han comunicadoocasionalmente casos de infecciones graves con riesgo para la vida como meningitis, endocarditis infecciosa, tuberculosise infección micobacteriana atípica.En pacientes tratados con Cellcept se han noti�cado casos, alguno de ellos mortales,de Leucoencefalopatía Multifocal Progresiva (LMP). En general, los casos noti�cados presentaban factores de riesgo parala LMP, como tratamiento inmunosupresor y función inmune deteriorada.. Se ha comunicado agranulocitosis(≥1/1000<1/100), y neutropenia en algunos pacientes, por lo que se aconseja monitorizar regularmente a los pacientes en tratamientocon CellCept (ver sección 4.4 ) Se han noti�cado casos de anemia aplásica y depresión de médula ósea en pacientestratados con CellCept, algunos de los cuales han provocado la muerte. Hipersensibilidad: Se han noti�cado reacciones dehipersensibilidad, incluyendo edema angioneurótico y reacción ana�lactica. Se han reportado casos de aplasia pura decélulas rojas (APCR) en pacientes tratados con Cellcept en combinación con otros agentes inmunosupresores. 4.9Sobredosis Se han noti�cado casos de sobredosis con micofenolato mofetilo en ensayos clínicos y durante la experienciapostcomercialización. En muchos de estos casos, no se noti�caron reacciones adversas. En los casos de sobredosis en loscuales se noti�caron reacciones adversas, estas reacciones estaban dentro del per�l de seguridad conocido delmedicamento. Se cree que una sobredosis de micofenolato mofetilo posiblemente podría producir una sobresupresión delsistema inmune y aumentar la susceptibilidad a infecciones y una supresión de la médula ósea (ver sección 4.4). Si sedesarrolla neutropenia, se debería interrumpir o reducir la dosis de CellCept (ver sección 4.4). No se preveé la eliminaciónde cantidades clínicamente signi�cativas de MPA o MPAG por hemodiálisis. Los secuestradores de ácidos biliares, comola colestiramina, pueden eliminar el MPA disminuyendo la re-circulación enterohepática del fármaco (ver sección 5.2). 5.PROPIEDADES FARMACOLÓGICAS 5.1 Propiedades farmacodinámicas Grupo farmacoterapéutico: agentesinmunosupresores código ATC L04AA06 El micofenolato mofetilo es el éster 2-morfolinoetílico del MPA. El MPA es uninhibidor potente, selectivo, no competitivo y reversible de la inosinmonofosfato-deshidrogenasa; inhibe, por tanto, la síntesisde novo del nucleótido guanosina, sin incorporación al ADN. El MPA tiene unos efectos citostáticos más potentes en loslinfocitos que en otras células ya que los linfocitos T y B dependen de una manera decisiva para su proliferación de lasíntesis de novo de purinas, mientras que otros tipos de células pueden utilizar mecanismos de recuperación de purinas.5.2 Propiedades farmacocinéticas Tras la administración oral, el micofenolato mofetilo se absorbe rápida y ampliamente;a continuación se transforma en MPA, su metabolito activo, en un proceso de metabolización presistémica completa. Laactividad inmunosupresora de CellCept está correlacionada con la concentración del MPA, según ha quedado demostradopor la supresión del rechazo agudo a continuación del trasplante renal. La biodisponibilidad media del micofenolato mofetilopor vía oral, determinada mediante el AUC del MPA, es del 94 % en comparación con la del micofenolato mofetilointravenoso. Los alimentos no tuvieron ningún efecto en el grado de absorción (AUC del MPA) del micofenolato mofetiloadministrado a dosis de 1,5 g, dos veces al día, a transplantados renales. Sin embargo, se produjo una disminución deaproximadamente el 40 % en la Cmáx del MPA en presencia de alimentos. El micofenolato mofetilo no es detectablesistémicamente en el plasma tras su administración oral. El MPA, a concentraciones clínicamente relevantes, se une a laalbúmina plasmática en un 97 %. Tras la administración intravenosa, el micofenolato mofetilo experimenta unametabolización rápida y completa a MPA, su metabolito activo. El MPA, a concentraciones clínicamente relevantes, se unea la albúmina plasmática en un 97 %. La sustancia de origen, el micofenolato mofetilo, puede ser detectado sistémicamentedurante la perfusión intravenosa; sin embargo, tras la administración oral permanece por debajo del límite de cuanti�cación(0,4 microgramo/mL). Como consecuencia de la recirculación enterohepática, se suelen observar aumentos secundariosde la concentración plasmática de MPA después de aproximadamente 6 - 12 horas de la administración. Con lacoadministración de colestiramina (4 g tres veces al día), se produce una reducción del AUC del MPA del orden del 40 %,lo que es indicativo de una recirculación enterohepática importante. El MPA se metaboliza principalmente por la glucuronil-transferasa, para formar el glucurónido fenólico del MPA (MPAG), sin actividad farmacológica. La cantidad de sustanciaque se excreta en forma de MPA con la orina es despreciable (< 1 % de la dosis). Tras la administración por vía oral demicofenolato mofetilo radiomarcado, la recuperación de la dosis administrada es completa. Un 93 % de la dosis se recuperóen la orina y un 6 % en las heces. La mayor parte de la dosis administrada (alrededor del 87 %) se excreta por la orina enforma de MPAG. El MPA y el MPAG no se eliminan por hemodiálisis a las concentraciones encontradas a nivel clínico. Sinembargo, a concentraciones plasmáticas elevadas de MPAG (> 100 microgramo/mL), se eliminan pequeñas cantidadesdel mismo. En el postoperatorio inmediato (< 40 días posteriores al trasplante), los pacientes sometidos a trasplante renal,cardíaco y hepático tienen unos valores medios del AUC del MPA aproximadamente un 30 % mas bajo y una Cmaxaproximadamente un 40 % mas baja que en el periodo postoperatorio tardío (3-6 meses posteriores al trasplante).Insu�ciencia renal: En un ensayo a dosis única (6 individuos/grupo), se observó que para los individuos con insu�cienciarenal crónica grave (�ltración glomerular < 25 mL·min-1·1,73 m-2), el valor medio del AUC para el MPA plasmático fue deun 28 – 75 % superior que para individuos sanos normales o en pacientes con menor deterioro renal. Sin embargo, el valormedio del AUC del MPAG tras una dosis única en los sujetos con insu�ciencia renal grave, fue 3 - 6 veces superior alpresentado en los pacientes con deterioro renal leve o en los voluntarios sanos, lo que concuerda con la eliminación renalconocida del MPAG. No se ha estudiado la administración de dosis múltiples de micofenolato mofetilo en pacientes coninsu�ciencia renal crónica grave. No existen datos sobre los pacientes sometidos a trasplante cardíaco o hepático coninsu�ciencia renal crónica grave. Retraso de la función renal del injerto: En pacientes con retraso funcional del riñóntrasplantado, el valor medio del AUC (0-12) del MPA fue comparable al observado en los pacientes sin retraso funcionalpostrasplante. Asimismo, el valor medio del AUC (0-12) del MPAG fue 2 - 3 veces superior al de los pacientes trasplantadossin retraso de la función del órgano. Puede darse un aumento transitorio de la fracción libre y la concentración en plasmadel MPA en pacientes con retraso de la función renal del injerto. No se considera necesario realizar un ajuste de la dosisde CellCept. Insu�ciencia hepática: En voluntarios con cirrosis alcohólica se comprobó que los procesos de glucuronidaciónhepática del MPA estaban relativamente poco afectados por la enfermedad del parénquima hepático. Los efectos de lahepatopatía en este proceso dependen probablemente de la enfermedad concreta de que se trate. Sin embargo, unahepatopatía con predominio de la afectación biliar, como la cirrosis biliar primaria, puede tener un efecto diferente. Niñosy adolescentes (entre 2 y 18 años): Se han evaluado los parámetros farmacocinéticos de 49 pacientes pediátricos contrasplante renal, tratados dos veces al día con 600 mg/m2 de micofenolato mofetilo administrado por vía oral. Con esta

dosis se alcanzaron valores del AUC del MPA similares a los observados en pacientes adultos con trasplante renal, tratadoscon 1 g de CellCept dos veces al día, en los periodos post-trasplante inicial y tardío. Los valores del AUC del MPA en todoslos grupos de edad fueron similares en los periodos post-trasplante inicial y tardío. Pacientes ancianos (≥ 65 años): No seha evaluado formalmente el comportamiento farmacocinético de CellCept en pacientes ancianos. Anticonceptivos orales:La farmacocinética de los anticonceptivos orales no se vio afectada por la administración conjunta con CellCept (ver ademássección 4.5). En un ensayo realizado en 18 mujeres (que no tomaban otro inmunosupresor), durante 3 ciclos menstrualesconsecutivos, en el que se administraban conjuntamente CellCept (1 g, dos veces al día) y anticonceptivos oralescombinados, que contenían etinilestradiol (de 0,02 mg a 0,04 mg) y levonorgestrel (de 0,05 mg a 0,15 mg), desogestrel(0,15 mg) o gestodeno (de 0,05 mg a 0,10 mg), no se puso de mani�esto una in�uencia clínicamente relevante de CellCeptsobre la capacidad de los anticonceptivos orales para suprimir la ovulación. Los niveles séricos de LH, FSH y progesteronano se vieron afectados signi�cativamente. 5.3 Datos preclínicos sobre seguridad En modelos experimentales, elmicofenolato mofetilo no fue carcinogénico. La dosis más alta ensayada en los estudios de carcinogénesis en animalesresultó ser aproximadamente de 2 a 3 veces la exposición sistémica (AUC o Cmáx) observada en pacientes trasplantadosrenales a la dosis clínica recomendada de 2 g/ día, y de 1,3 a 2 veces la exposición sistémica (AUC o Cmáx) observada enpacientes sometidos a trasplante cardíaco con la dosis clínica recomendada de 3 g/ día. Dos estudios de genotoxicidad(ensayo in vitro de linfoma de ratón y ensayo in vivo del test del micronúcleo en médula ósea de ratón) indicaron que elmicofenolato mofetilo tenía potencial para causar aberración cromosómica. Estos efectos pueden estar relacionados conel mecanismo de acción, p.ej. inhibición de la síntesis de nucleótidos en células sensibles. No se demostró actividadgenotóxica en otros ensayos in vitro para la detección de la mutación de genes. El micofenolato mofetilo no tuvo efectoalguno en la fertilidad de las ratas macho a dosis orales de hasta 20 mg·kg-1·día-1. La exposición sistémica a esta dosisrepresenta de 2- 3 veces la exposición clínica a la dosis recomendada de 2 g/ día en los pacientes sometidos a trasplanterenal y de 1,3 a 2 veces la exposición clínica con la dosis recomendada de 3 g/ día en los pacientes sometidos a trasplantecardíaco. En un estudio de la reproducción y la fertilidad llevado a cabo en ratas hembra, dosis orales de 4,5 mg·kg-1·día-

1 causaron malformaciones (incluyendo anoftalmia, agnatia, e hidrocefalia) en la primera generación de crías, sin que sedetectara toxicidad en las madres. La exposición sistémica a esta dosis fue aproximadamente 0,5 veces la exposiciónclínica a la dosis recomendada de 2 g/ día en los pacientes sometidos a trasplante renal y de 0,3 veces la exposición clínicacon la dosis recomendada de 3 g/ día en los pacientes sometidos a trasplante cardíaco. No se evidenció ningún efecto enla fertilidad y la reproducción de las ratas madre ni en la generación siguiente. En los estudios de teratogenia se produjeronresorciones fetales y malformaciones en ratas con dosis de 6 mg·kg-1· día-1 (incluyendo anoftalmia, agnatia, e hidrocefalia)y en conejos con dosis de 90 mg·kg-1·día-1 (incluyendo anormalidades cardiovasculares y renales, como ectopia del corazóny riñones ectópicos, y hernia diafragmática y umbilical), sin que se registrara toxicidad materna. La exposición sistémica aestos niveles es aproximadamente equivalente o menor a 0,5 veces la exposición clínica a la dosis recomendada de 2 g/día en los pacientes sometidos a trasplante renal y en torno a 0,3 veces la exposición clínica con la dosis recomendada de3 g/ día en los pacientes sometidos a trasplante cardíaco. Ver sección 4.6. Los sistemas hematopoyético y linfoide fueronlos primeros órganos afectados en los estudios toxicológicos realizados con micofenolato mofetilo en la rata, ratón, perroy mono. Estos efectos se observaron con valores de exposición sistémica equivalentes o inferiores a la exposición clínicacon la dosis recomendada de 2 g/ día en trasplantados renales. En el perro se observaron efectos gastrointestinales aniveles de exposición sistémica equivalentes o menores a la exposición clínica a las dosis recomendadas. En el mono, a ladosis más alta (niveles de exposición sistémica equivalente a o mayor que la exposición clínica), también se observaronefectos gastrointestinales y renales que concuerdan con la deshidratación. El per�l toxicológico no clínico de micofenolatomofetilo parece estar de acuerdo con los acontecimientos adversos observados en los ensayos clínicos humanos que ahoraproporcionan datos de seguridad de mas relevancia para la población de pacientes. (ver sección 4.8). 6. DATOSFARMACÉUTICOS 6.1 Lista de excipientes Comprimidos de CellCept: celulosa microcristalina povidona (K-90)croscarmelosa sódica estearato magnésico Recubrimiento de los comprimidos: hipromellosa hidroxipropil celulosa dióxidode titanio (E171) polietilenglicol 400 índigo carmín en laca alumínica (E132) óxido de hierro rojo (E172) Cápsulas de CellCept:almidón de maíz pregelatinizado croscarmelosa sódica povidona (K-90) estearato magnésico Envoltura de la cápsula:gelatina índigo carmín (E132) óxido de hierro amarillo (E172) óxido de hierro rojo (E172) dióxido de titanio (E171) óxido dehierro negro (E172) hidróxido de potasio goma laca. CellCept 500 mg polvo para concentrado para solución para perfusiónPolisorbato 80 ácido cítrico ácido clorhídrico cloruro sódico CellCept 1 g/5 ml polvo para suspensión oral: sorbitol sílicecoloidal anhidra citrato sódico lecitina de soja sabor compuesto de frutas goma xantam aspartamo (E951)parahidroxibenzoato de metilo (E218) ácido cítrico anhidro *contiene una cantidad de fenilalanina equivalente a 2,78 mg/5 mlde suspensión. 6.2 Incompatibilidades No procede en caso de comprimidos y cápsulas. La solución para perfusión deCellCept 500 mg polvo para concentrado para solución para perfusión no debe ser mezclada o administrada de formaconcurrente a través del mismo catéter con otros medicamentos intravenosos u otras mezclas para perfusión.6.3 Periodode validez 3 años para comprimidos y cápsulas. Polvo para concentrado para solución para perfusión: 3 años. Soluciónreconstituida y solución para perfusión: Si la solución para perfusión no se prepara inmediatamente antes de laadministración, el comienzo de la administración de la solución para perfusión debe ser dentro de las 3 horas siguientes ala reconstitución y dilución del medicamento. El polvo para suspensión oral tiene un periodo de validez de 2 años. Lasuspensión reconstituida tiene un periodo de validez de 2 meses. 6.4 Precauciones especiales de conservación Noconservar a temperatura superior a 30ºC.Conservar en el embalaje original para protegerlo de la humedad. Polvo paraconcentrado para solución para perfusión: No conservar a temperatura superior a 30ºC. Solución reconstituida y soluciónde perfusión: Conservar entre 15 y 30ºC. 6.5 Naturaleza y contenido del envase CellCept 500 mg comprimidos: 1 estuchecontiene 50 comprimidos (en blísters de 10 unidades). 1 estuche contiene 150 comprimidos (en blísters de 10 unidades).CellCept 250 mg cápsulas: 1 estuche contiene 100 cápsulas (en blísters de 10 unidades). 1 estuche contiene 300 cápsulas(en blísters de 10 unidades). Viales de vidrio transparente tipo I de 20 mL con tapón de caucho butílico gris y precinto dealuminio con cápsulas de plástico de fácil apertura. CellCept 500 mg polvo para concentrado para solución para perfusiónestá disponible en envases de 4 viales. Cada frasco contiene 110 g de polvo para suspensión oral. El volumen de lasuspensión cuando se reconstituye es de 175 ml, proporcionando un volumen útil de 160-165 ml. También se incluyen unadaptador del frasco y 2 dispensadores orales. 6.6 Precauciones especiales de eliminación y otras manipulacionesDado que se ha observado efecto teratogénico para el micofenolato mofetilo en la rata y el conejo, no deben triturarse loscomprimidos de CellCept, no deben abrirse o triturarse las cápsulas de CellCept. Evítese la inhalación del polvo contenidoen las cápsulas de CellCept, así como el contacto directo con la piel o las mucosas. En caso de contacto, lávese la parteafectada con abundante agua y jabón; los ojos deben lavarse con agua corriente. La eliminación del medicamento noutilizado y de todos los materiales que hayan estado en contacto con él se realizará de acuerdo con las normativas locales.Preparación de la Solución de Perfusión (6 mg/mL) CellCept 500 mg polvo para concentrado para solución para perfusiónno contiene conservantes antibacterianos; por tanto, la reconstitución y dilución del producto debe realizarse bajocondiciones asépticas. CellCept 500 mg polvo para concentrado para solución para perfusión debe prepararse en dospasos: el primer lugar reconstituir con una solución para perfusión intravenosa de glucosa al 5 % y el segundo lugar diluircon una solución para perfusión intravenosa de glucosa al 5 %. A continuación se da una descripción detallada de lapreparación: Paso 1. a. Para cada dosis de 1 g se emplean dos viales de CellCept 500 mg polvo para concentrado parasolución para perfusión. Reconstituir el contenido de cada vial mediante una inyección de 14 mL de solución para perfusiónintravenosa de glucosa al 5 %. b. Agitar suavemente el vial para disolver el medicamento, se produce una soluciónligeramente amarilla. c. Antes de seguir diluyendo, inspeccionar la solución resultante en lo relativo a partículas y alteracióndel color. Descartar el vial si se observan partículas o alteración del color. Paso 2. a. Posteriormente diluir el contenido dedos viales reconstituidos (aprox. 2 x 15 mL) en 140 mL de solución para perfusión intravenosa de glucosa al 5 %. Laconcentración �nal de la solución es de 6 mg/mL de micofenolato mofetilo. b. Inspeccionar la solución para perfusión enlo relativo a partículas o alteración del color. Si se observan partículas o alteración del color desechar la solución paraperfusión. Si la solución para perfusión no se prepara inmediatamente antes de la administración, el comienzo de laadministración de la solución debe efectuarse dentro de las 3 horas siguientes a la reconstitución y dilución delmedicamento. Mantener las soluciones entre 15 y 30ºC. Preparación de la Suspensión oral Se recomienda que antes dela dispensación al paciente, CellCept 1 g/5 ml polvo para suspensión oral sea reconstituida por el farmacéutico. Preparaciónde la suspensión 1. Golpear ligeramente el frasco cerrado varias veces para soltar el polvo. 2. Medir 94 ml de agua puri�cadaen una probeta. 3. Añadir al frasco aproximadamente la mitad de la cantidad total de agua puri�cada y agitar bien el frascocerrado durante 1 minuto aproximadamente. 4. Añadir el resto de agua y agitar bien el frasco cerrado durante 1 minutoaproximadamente. 5. Quitar el cierre a prueba de niños y acoplar el adaptador en el cuello del frasco. 6. Cerrar el frascoherméticamente con el cierre a prueba de niños. Esto asegurará la colocación correcta del adaptador en el frasco y elestado del cierre a prueba de niños. 7. Escribir en la etiqueta del frasco la fecha de caducidad de la solución reconstituida.(El periodo de validez de la suspensión reconstituida es de dos meses) 7. TITULAR DE LA AUTORIZACIÓN DECOMERCIALIZACIÓN Roche Registration Limited 6 Falcon Way Shire Park Welwyn Garden City AL7 1TW Reino Unido 8.NÚMERO(S) DE AUTORIZACIÓN DE COMERCIALIZACIÓN EU/1/96/005/002 CellCept (50 comprimidos) EU/1/96/005/004CellCept (150 comprimidos) EU/1/96/005/001 CellCept (100 cápsulas) EU/1/96/005/003 CellCept (300 cápsulas)EU/1/96/005/006 (1 frasco de 110 g) EU/1/96/005/005 CellCept (4 viales) 9. FECHA DE LA PRIMERAAUTORIZACIÓN/RENOVACIÓN DE LA AUTORIZACIÓN Fecha de la primera autorización: 14 de febrero de 1996 Fecha dela última renovación: 14 de febrero de 2006 10. FECHA DE LA REVISIÓN DEL TEXTO 28 de febrero de 2008 La informacióndetallada de este medicamento está disponible en la página web de la Agencia Europea del Medicamento (EMEA)http://www.emea.europa.eu/ PRECIO CellCept 500 mg (50 comprimidos) y CellCept 250 mg (100 cápsulas): PVL 99,26euros; PVP IVA 150,98 euros. CellCept 500 mg, polvo para concentrado para solución para perfusión: PVL 49,81 euros;PVP IVA 77,76 euros. Cellcept polvo para suspensión oral: PVL 138,98 euros; PVP IVA 192,29 euros.

Trastornos vasculares Muy frecuentes - Frecuentes Hipotensión, hipertensión, vasodilatación Trastornos respiratorios, torácicos y mediastínicos Muy frecuentes - Frecuentes Derrame pleural, disnea, tos Trastornos gastrointestinales Muy frecuentes Vómitos, dolor abdominal, diarrea, náuseas Frecuentes Hemorragia gastrointestinal, peritonitis, íleo, colitis, úlcera gástrica, úlcera duodenal, gastritis, esofagitis, estomatitis, estre-

ñimiento, dispepsia, �atulencia, eructos. Trastornos hepatobiliares Muy frecuentes - Frecuentes Hepatitis, ictericia, hiperbilirrubinemia

Trastornos de la piel y del tejido subcutáneo Muy frecuentes - Frecuentes Hipertro�a cutánea, rash, acné, alopecia Trastornos musculoesqueléticos y del tejido conjuntivo Muy frecuentes - Frecuentes Artralgia Trastornos renales y urinarios Muy frecuentes - Frecuentes Alteración renal Trastornos generales y alteraciones en el lugar de administración Muy frecuentes - Frecuentes Edema, pirexia, escalofríos, dolor, malestar general, astenia Exploraciones complementarias Muy frecuentes - Frecuentes Aumento de los niveles enzimáticos, aumento de creatinina sérica, aumento de lactato deshidrogenasa sérica, aumento de

urea sérica, aumento de fosfatasa alcalina sérica, pérdida de peso Nota: 501 (2 g diarios de CellCept), 289 (3 g diarios de CellCept) y 277 (2 g diarios de CellCept IV/3 g diarios de CellCept oral) pacientes fue-ron tratados en ensayos en fase III para la prevención del rechazo en trasplante renal, cardíaco y hepático respectivamente.

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Volume III • Number 3 • September-December 2009 ISSN: 1887 ...€¦ · Cytomegalovirus and Epstein-Barr Virus Infection in Pediatric Liver Transplants Esteban Frauca, Loreto Hierro