IL10 and systemic-onset juvenile idiopathic arthritis: In this study, we evaluated the serum IL-10 levels and investigated its clinical relevance in systemic-onset juvenile idiopathic arthritis (SoJIA).<h4>Methods</h4>IL-10 levels were determined in 21 patients diagnosed with SoJIA and 35 patients with fever diseases which were suspected as SoJIA, and IL-10 levels were compared between SoJIA patients with regard to disease activity, disease courses, and other biomarkers.<h4>Results</h4>Patients with SoJIA had significantly higher levels of IL-10 compared to patients with other febrile diseases.