S100 proteins, cytokines, and chemokines as tear biomarkers in children with juvenile idiopathic arthritis-associated uveitis.

PURPOSE: Biomarkers for juvenile idiopathic arthritis-associated uveitis (JIA-U) are needed. We aimed to measure inflammatory biomarkers in tears as a non-invasive method to identify biomarkers of uveitis activity. METHODS: Tears were collected from children with JIA-U (n=20) and pediatric controls (n=20) using Schirmer strips. S100A8, A9, A12, IL-18, IL-8, IP-10, MCP-1, RANTES, and sICAM-1 were measured by ELISA and Luminex assays. Levels of biomarkers were compared between children with JIA-U and controls, and active and inactive JIA-U. RESULTS: IL-8, sICAM-1, and S100A12 levels were similar between JIA-U and controls, but differed by activity. Active JIA-U had significantly increased S100A12 compared to inactive JIA-U (mean 27,722.5 pg/ML (SE 1.3) vs. 5,937.2 (1.3), p=0.002), IL-8 (73.5 [1.2] vs. 36.2 [1.2], p=0.009), and sICAM-1 (15,822.7 [1.2) vs. 8,778.0 [1.6], p=0.024). CONCLUSION: We detected inflammatory biomarkers non-invasively in tears of children with JIA-U. IL-8, sICAM-1, and S100A12 are potential biomarkers for uveitis activity.