Lupus Allan D. Corpuz, MD, FPCP, DPRA

Section of Rheumatology Department of Medicine

Philippine GENERAL HOSPITAL

Objectives •  Recognize the clinical manifestations of SLE •  Order the important diagnostic tests •  Enumerate the treatment modalities •  Know when and where to refer •  Counsel patients with the disease

What is SLE: Systemic

What is SLE: Autoimmune

pDCs  

Res(ng  epithelium   Dysregulated  (ssue  

Chemokine  

BAFF/BlyS  ANA  

Type  I  IFNs  

virus  

AutoAb  

IC  1.  Voulgarelis  M,  et  al.  Nat  Rev  Rheumatol.2010;101:529-­‐537.  2.  Jonsson  R,  et  al.  Immunol  LeQ.  2011;141:1-­‐9.  3.  Nocturne  G,et  al.  Nat  Rev  Rheumatol.  2013  Jul  16.  doi:  10.1038  

IL-­‐1β,  IFN-­‐γ,T

NF-­‐α

What is SLE: Autoimmune

What is SLE: Autoimmune

What is SLE: Chronic, Relapsing, Inflammatory

What is SLE: Primarily Female

9 1

The Impaired Immune System in SLE

Pathogenesis

T  cells  

B  cells  

Complement  

Pathogenesis: Panoramic View

APOPTOSIS: Programmed

Cell Death

But some things don’t go as programmed…

Complement in the Pathogenesis of SLE

What it is NOT

In Summary •  What it Is –  Systemic –  Autoimmune –  Chronic –  Relapsing –  Inflammatory –  Often febrile –  Female –  Impaired Immune System –  Can be controlled

•  What It is Not –  Uniformly fatal –  Hopeless –  Curable

DIAGNOSIS

1997 update of the 1982 ACR Classification Criteria

Malar rash

Discoid Rash

Discoid Rash

Oral Ulcer

Photosensitive Rash

Serositis

Non-erosive arthritis

Nephritis

Seizures Psychosis

WBC < 4000/mm3 Platelet <100,000/mm3

Hemolytic Anemia

Positive Antinuclear Antibody

Immunologic Disorder •  Anti-dsDNA •  Anti-Smith •  Positive finding of aPL Abs – Abnormal serum concentration of IgG/IgM

Anticardiolipin Abs –  (+) test result for lupus anticoagulant – False (+) serologic test for syphilis known to be (+) for

6mos and confirmed by T.pallidum immobilization or FTA-Abs test

Frequency of Manifestations of SLE

2012 SLICC Criteria

In Summary: SOAP BRAIN MD •  Serositis •  Oral Ulcer •  Arthritis •  Photosensitivity •  Blood disorder •  Renal Disorder •  ANA •  Immunologic Disorder •  Neurologic Disroder •  Malar rash •  Discoid Rash

At least

4 of the11

Fulfillment of these criteria is NOT an

absolute requirement for Dx

 

DIAGNOSTIC TESTING

• No clinical manifestation or lab test can serve as a definitive diagnostic test

•  SLE is diagnosed based on a constellation of characteristic signs and symptoms and lab findings in the appropriate clinical context

Serologic Tests 790 PART 7 | DIAGNOSTIC TESTS AND PROCEDURES IN RHEUMATIC DISEASES

Because of the characteristic presence of these autoantibod-ies among the ANA diseases, ANAs have long been specu-lated to play a role in disease pathogenesis. Anti-DNA antibodies, for instance, have been suspected to promote inflammation in SLE nephritis via immune complex deposi-tion, direct binding to cross-reactive glomerular antigens, and/or intracellular penetration and induction of cellular toxicity.6 Similarly, ribonucleoprotein antibodies such as anti-Ro/SSA, anti-La/SSB, and anti-Sm have been impli-cated in the pathogenesis of cutaneous or cardiac manifesta-tions by penetrating live cells and/or binding to exposed antigens in the skin and/or the heart.7,8 Sera containing anti-Scl-70 (topoisomerase I) activity can induce high levels of interferon (IFN)-α, correlating with diffuse cutane-ous scleroderma and lung fibrosis9; also, anti-Jo-1- or anti-Ro/SSA-positive sera from myositis patients have been demonstrated to induce type I IFN and/or intercellular adhesion molecule (ICAM)-1 on endothelial cells.10,11

However, autoantibodies alone appear insufficient to account for disease pathogenesis. Induction of type I IFN activity by anti-Ro/SSA–containing sera, for instance, appears restricted to patients with SLE or SS, not asymp-tomatic individuals,12 and surface binding of topoisomerase I may be required for a pathogenic effect of anti-Scl-70 antibodies.13 This may reflect additional biologic issues among or effects of the autoantigens themselves, such as novel conformations or epitopes: for instance, a proteolyti-cally sensitive conformation of histidyl-transfer RNA syn-thetase (HisRS), the target of the pulmonary fibrosis–related Jo-1–specific antibody, has been described in the lung,14 and an apoptope (epitope expressed on apoptotic cells) of Ro/SSA may be specific to SLE, suggesting a unique role of apoptosis in disease pathogenesis.15 The autoantigens them-selves may have unique biologic functions: 60-kD Ro/SSA, for instance, may serve as a receptor for the antiphospholipid-related β2-glycoprotein I, and this dynamic may account for differences in Ro antibody pathogenicity.16 However, many autoantigens likely have intrinsic proinflammatory proper-ties, such as stimulation of innate inflammation by DNA and RNA via Toll-like receptors (TLRs) 3, 7, and 9,17,18 or induc-tion of smooth muscle responses by the centromere protein CENP-B via CCR3.19 Apparent remission of SLE in a patient has been correlated with loss of TLR responsiveness, anti-body deficiency, and disappearance of anti-DNA, supporting such concepts.20 Thus the pathogenesis of the connective tissue diseases appears to reflect a complex interplay between direct inflammatory or other biologic effects of the autoan-tigens and consequences of autoantibody responses.

METHODS OF DETECTION

Table 55-1 Antinuclear Antibody (ANA)-Associated Diseases and Related Conditions

ConditionPatients with ANAs (%)

Diseases for Which ANA Testing Is Helpful for Diagnosis

Systemic lupus erythematosus 99-100Systemic sclerosis 97Polymyositis/Dermatomyositis 40-80Sjögren’s syndrome 48-96

Diseases in Which ANA Is Required for Diagnosis

Drug-induced lupus 100Mixed connective tissue disease 100Autoimmune hepatitis 100

Diseases in Which ANA May Be Useful for Prognosis

Juvenile idiopathic arthritis 20-50Antiphospholipid antibody syndrome 40-50Raynaud’s phenomenon 20-60

Some Diseases for Which ANA Typically Is Not Useful

Discoid lupus erythematosus 5-25Fibromyalgia 15-25Rheumatoid arthritis 30-50Relatives of patients with autoimmune disease 5-25Multiple sclerosis 25Idiopathic thrombocytopenic purpura 10-30Thyroid disease 30-50Patients with silicone breast implants 15-25Infectious disease Varies widelyMalignancies Varies widely

Healthy (“Normal”) Individuals

≥1 : 40 20-30≥1 : 80 10-12≥1 : 160 5≥1 : 320 3

Adapted from Kavanaugh A, Tomar R, Reveille J, et al, American College of Pathologists: Guidelines for clinical use of the antinuclear antibody test and tests for specific autoantibodies to nuclear antigens, Arch Pathol Lab Med 124:71–81, 2000.

detected by FANA testing led to the description of Smith (Sm), nuclear ribonucleoprotein (nRNP), Ro/Sjögren’s syn-drome (SSA), and La/SSB specificities, which later gained further biologic prominence with the demonstration that their autoantigens play prominent roles in cellular homeo-stasis (e.g., snRNPs, targets of anti-Sm and anti-nRNP) and in regulation of premessenger RNA splicing.5 Subsequent investigations have revealed an ever growing array of auto-antigens (Table 55-2), many of which remain largely uncharacterized. Thus, ANAs not only serve as diagnostic markers in autoimmunity but to this day have greatly aided studies on cellular biochemistry.

RELEVANCE OF ANTINUCLEAR ANTIBODIES TO DISEASE PATHOGENESIS

KEY POINT

ANAs and their respective autoantigens have been implicated in disease pathogenesis as producing directly toxic or other proinflammatory effects.

KEY POINTS

The gold standard screening test for ANAs is the fluorescent ANA test.

Many antibody tests, including ANA screening in some laboratories, are performed via enzyme-linked immunosorbent assay (ELISA) because this method affords higher throughput testing, but this technique often results in lower specificity.

Optimal clinical interpretation of ANA tests requires knowledge of the technique(s) used in each specific case.

Antinuclear Antibodies •  Anti-nuclear (or anticytoplasmic) Abs bind to cells fixed on a

slide •  Addition of a secondary Ab (with an attached fluorescent

dye) •  Dilution at 1:40 and 1:160 buffered solution •  The titer is a measure of the amount of ANA in the blood

(higher titer – more autoABs) •  Standardization: 30% of normal individuals will have a

positive test at 1:40 (sensitive) •  At 1:160, only 5% of normal individuals will have a positive

test (specific)

False Positives •  32% in normal individuals (>1:40) •  13% (>1:80) •  3% (>1:320) •  Relatively constant over time

Tan  EM,  Feltkamp  TE,  Smolen  JS,  et  al.  Range  of  an(nuclear  an(bodies  in  "healthy"  individuals.  Arthri(s  Rheum  1997;  40:1601.  

False Negatives •  From technical and physical nuances •  Method of substrate fixation, the solubility of the

antigen (eg, Ro, La, PCNA, and Ku), and the localization of the antigen outside the nucleus (ie, Jo-1 and single stranded DNA)

•  There is rarely any need to request testing for antibodies to DNA, Sm, RNP, Ro/SSa, or La/SSb unless the ANA is known to be positive

•  Elderly (<1:80 titer) Tan  EM,  Feltkamp  TE,  Smolen  JS,  et  al.  Range  of  an(nuclear  an(bodies  in  "healthy"  individuals.  Arthri(s  Rheum  1997;  40:1601.  

IF (1:160) vs ELIA •  ELIA: recombinant technology (using kits); faster,

no training needed •  Agreement: 87-95% •  Sensitivity: 69-98% •  Specificity: 81-98%

•  Still with high # of false +

Jaskowski  TD,  Schroder  C,  Mar(ns  TB,  Mouritsen  CL,  Litwin  CM,  Hill  HR:  Screening  for  an(nuclear  an(bodies  by  enzyme  immu-­‐  noassay.  Am  J  Clin  

Pathol  1996,  105:468-­‐473.  

Bizzaro  N,  Tozzoli  R,  Tonu^  E,  Piazza  A,  Manoni  F,  Ghirardello  A,  Basse^  D,  Villalta  D,  Pradella  M,  Rizzo^  P:  Variability  between  methods  to  determine  ANA,  an;-­‐dsDNA  and  an;-­‐ENA  

auto  an;bodies:  a  collabora;ve  study  with  the  biomedical  industry.  J  Immunol  Methods  1998,  219:99-­‐107.  

Interpretation

A negative or low titer ANA-IF in the

setting of low clinical suspicion of rheumatic disease usually indicates the

absence of significant ANAs and

argues against the diagnosis of one of the ANA diseases

When to treat Although the ANA-IF pattern and titer may provide

insight into the specific auto-Ag(s) targeted, as well as the potential likelihood of CTD,

such correlations should ONLY guide, NOT absolutely determine, clinical

decisions

Some specific ANAs possess diagnostic significance and would need follow-up with specialized assays BUT ONLY IN THE SETTING OF STRONG

CLINICAL SUSPICION because: 1. the PPV of an ANA in the absence of other clinical signs of CTD is low, in part because it may precede clinical disease by many years 2. because of the relatively high incidence of ANA in normal individuals

If specific testing is negative in the setting of high clinical suspicion, repeat testing at a later

date may be warranted, because titers of such autoantibodies can fluctuate over time, irrespective of disease course.

General Guidelines •  -ANA testing is not helpful in confirming a

diagnosis of rheumatoid arthritis or osteoarthritis therefore should not be used in such conditions.

•  - ANA testing is not recommended to evaluate fatigue, back pain or other musculoskeletal pain unless accompanied by one or more of the clinical features in favor of a CTD.

•  - ANA testing should usually be ordered only once. •  - Positive ANA tests do not need to be repeated.

•  - Negative tests need to be repeated only if there is a strong suspicion of an evolving CTD or a change in the patient's illness suggesting the diagnosis should be revised.

•  - A positive ANA test is important only in conjunction with clinical evaluation and in the absence of symptoms and signs of a CTD; a positive ANA test only confounds the diagnosis. A positive ANA test can also be seen in healthy individuals, particularly the elderly or in a wide range of diseases other than CTD, where it has no diagnostic or prognostic value.

Kavanaugh  A,  Tomar  R,  Reveille  J,  Solomon  DH,  Homburger  HA:  Guidelines  for  Clinical  Use  of  the  An;nuclear  An;body  Test  and  Tests  for  Specific  Auto  an;bodies  to  Nuclear  An;gens.  

Arch  Pathol  Lab  Med  2000,  124:71-­‐81.  

Guidelines  and  Protocols  Advisory  CommiOee.  BCGuide-­‐  lines.ca  2007.  

Other Serologic Tests

Other Tests •  CBC with platelet count •  U/A, 24 hour urine studies (TV, TP, Crea) •  BUN, Creatinine •  Electrolytes •  LFTs •  CXR •  2D Echo •  Kidney Biopsy •  Complement (C3, C4, CH50)

IMPACT on LIFE •  Chronically fatigued: vicious cycle •  Inability to finish school and find jobs •  Inability to sustain jobs •  Depression and Anxiety •  Family Support

SUMMARY •  Systemic autoimmune chronic relapsing

inflammatory disease •  Protean Manifestations (SOAP BRAIN MD) •  No definitive diagnostic test •  Use and Interpret S/Sx and tests based on a

clinical context •  Poor HRQoL