Mizuta M, Shimizu M, Inoue N, et al. - This study was sought to evaluate the clinical significance of serum interleukin-18 (IL-18) levels for the diagnosis of systemic juvenile idiopathic arthritis (s-JIA) and to prognosticate the disease course of s-JIA. Researchers examined 116 individuals with s-JIA, 151 with other diseases, and 20 healthy controls. They assessed serum IL-18 levels longitudinally in 41 patients with s-JIA from the active phase through the remission phase. Via enzyme-linked immunosorbent assay, serum IL-18 levels were quantified and the results were compared with clinical features and the disease course of s-JIA. This study’s findings demonstrated that the serum IL-18 levels of > 4800 pg/ml may be useful for differentiating between s-JIA and other diseases. The outcomes suggested that assessing serum IL-18 levels might be beneficial for predicting the disease course and assessing remission in s-JIA.