Ocular Fluid Analysis in Children Reveals Interleukin‐29/Interferon‐λ1 as a Biomarker for Juvenile Idiopathic Arthritis–Associated Uveitis

Objective Childhood uveitis is a vision‐threatening inflammatory eye disease commonly attributed to juvenile idiopathic arthritis (JIA). The pathogenesis is poorly understood, which makes clinical management challenging. We analyzed soluble mediators in ocular fluid (aqueous humor [AqH]) and serum from children with JIA‐associated uveitis and common childhood uveitis to identify potential biomarkers and investigate the ocular microenvironment of this sight‐threatening eye disease. Methods AqH (n = 73) and paired serum (n = 66) samples were analyzed for 51 soluble mediators of inflammation by multiplex immunoassay. Twenty‐one children with JIA‐associated uveitis were compared to 15 children with chronic anterior uveitis without arthritis, 29 children with noninfectious idiopathic uveitis, and 8 children with noninflammatory conditions (controls). For visualization of the joint effect of multiple mediators, we used the radial coordinate visualization (Radviz) method. Optimal biomarker level cutoffs were also determined. Results The levels of interleukin‐29 (IL‐29)/interferon‐λ1 (IFNλ1) were decreased (P