Macrophage activation syndrome: a potentially fatal complication of rheumatic disorders

Results Totally 120 patients evaluated in this study including 108 JIA and 12 SLE. Five patients (4 girls and 1 boy) were considered to have evidence of MAS (incidence rate 4.2%). This rate for all JIA patients was 3.7% and for SoJIA, SLE and juvenile idiopaticarthritis (JIA) and polyarticular RF negative JIA was 8.2%, 16.7% and 2.8%, respectively. Mean age of MAS onset was 4.9 years, and duration of rheumatologic disease prior to MAS, 22 months. Four cases (80%) had abnormal liver function during the disease course, and coagulopathy. Bone marrow examination supported the diagnosis with definite haemophagocytosis in four cases (80%). The mortality rate was 40%. Conclusion Incidence of MAS in our JIA patients was about other studies, but the mortality rate was higher than other reports. Although MAS is a rare complication, because it is potentially fatal it must be considered in each childhood rheumatic disorders with suddenly changes in general condition and decrease peripheral cells.