Performance of interferon-gamma levels may lead to earlier diagnosing macrophage activation syndrome complicating systemic juvenile idiopathic arthritis.

Macrophage activation syndrome (MAS) is a severe, potentially fatal complication of rheumatic diseases, predominantly in systemic juvenile idiopathic arthritis (SJIA), and is considered as an autoinflammatory disease. Specific cytokine profiles could play a pivotal role in this inflammatory response. Gram-negative bacteremia, bacterial pneumonia, Kawasaki disease, and active SJIA exhibited similar cytokine profiles with elevated interleukin-6 (IL-6) and/or IL-10, further suggesting a correlation between them. Only when JIA is complicated by MAS can increased interferon-γ (IFN-γ) levels be observed. Therefore, increased serum IFN-γ levels could contribute to early diagnosing MAS in patients with SJIA in combination with other variables such as serum ferritin. A prospective multi-center study will be performed to further confirm the role of IFN-γ in the early recognition of MAS in SJIA.