Abstract

Systemic JIA (SJIA) is one subtype of juvenile idiopathic arthritis (JIA) that is a leading cause of short-term and long-term disability in children . Although SJIA repre-sents only 10% – 20% of all cases of JIA, it accounts for more than two-thirds of the mortality associated with this condition . The etiology and pathogenesis of SJIA remain unknown. Further understanding of SJIA pathogen-esis may facilitate new therapeutic approaches. Interleukin-18 (IL-18) was originally identified as an interferon gamma (IFN)-g-inducing factor, and IL-18 can induce INF- g production by splenocytes, hepatic lympho-cytes, and type 1T helper (Th1) cell clones . IL-18 levels have been shown to be abnormal in some inflammatory dis-eases and in autoimmune diseases. IL-18 expression has been reported to be up-regulated in lupus nephritis (LN),type 1 diabetes, and other autoimmune diseases . IL-18 binding protein (IL-18BP) is a circulating decoy receptor that binds to IL-18 with high affinity. IL-18BP can effi-ciently antagonize the biological activities of IL-18 . Experiments have shown that IL-18BP could prevent or at-tenuate the development of some autoimmune diseases .