- 1. Macrophage Activation Syndromein a Child withSystemic
Juvenile Rheumatoid ArthritisMina Hur, M.D., Young Chul Kim, M.D.,
Kyu Man Lee, M. D., and Kwang Nam Kim, M.D.* Departments of
Laboratory Medicine and Pediatrics*, Hallym University College of
Medicine, Seoul, Korea
- Macrophage activation syndrome (MAS) is a severe and
potentially life-
- threatening complication of rheumatic disorders in children,
especially those with systemic juvenile rheumatoid arthritis
(S-JRA).
- MAS is characterized by serious liver disease, hematologic
abnormalities, coagulopathy, and neurologic involvement. Laboratory
hallmarks are anemia, thrombocytopenia, & leukopenia in various
combinations, evidence of disseminated intravascular coagulation
(DIC), hypertriglyceridemia, increased LDH, and hemophagocytosis in
bone marrow.
- We describe a 13-month-old boy in whom MAS developed as a
complication of S-JRA.
- He suffered from fever and generalized rash followed by
multiple joints swelling for four months before admission. Physical
examination revealed cervical lymphadenopathy and
hepatosplenomegaly. Laboratory findings were: abnormal liver
enzymes, increased triglyceride and ferritin levels, coagulopathies
resembling DIC, anemia, and thrombocytopenia (Table 1).
- Bone marrow (BM) aspiration smear was diluted with no marrow
particle giving no diagnostic information. In BM biopsy, estimated
cellularity was about 90%, which was normocellular for age-related
value. Granulocytic and megakaryocytic hyperplasia were prominent
with suppressed erythropoiesis. Benign-appearing histiocytes were
increased and diffusely distributed with hemophagocytic features.
Presence of histiocytes was confirmed with positivity of CD68 stain
(Fig. 1).
- Clinical and laboratory improvement were observed during
hospital courses with corticosteroid and cyclosporine therapy (Fig.
2 & 3).
- Immunologic mechanisms causing MAS are still unclear. It is
thought, however, that T- or NK cell dysfunction leads to
macrophage activation and increased levels of many cytokines
(specifically, tumor necrosis factor alpha and interferon gamma)
released by macrophage or T-lymphoid cells initiate systemic
hemophagocytosis.
- This is the third case of MAS associated with S-JRA in Koreans,
and the first one, in which histiocytic hyperplasia was proven in
bone marrow.
INTRODUCTION CASE REPORT DISCUSSION Fig.1.(a) Bone marrow biopsy
section illustrates hypercellular marrow with granulocytic and
megakaryocytic hyperplasia (H & E stain,200).(b) Histiocytic
hyperplasia is prominently observed (CD 68 stain,200).