Intraocular Biomarker Identification in Uveitis Associated With Juvenile Idiopathic Arthritis

PURPOSE. To investigate the presence of biomarkers in aqueous humor (AH) from patients with uveitis associated with juvenile idiopathic arthritis (JIA). METHODS. AH (n = 73) and serum (n = 105) samples from 116 children were analyzed using surface enhanced laser desorption/ionization time of flight mass spectrometry (SELDI-ToF MS). The samples were divided into the following groups: JIA, silent chronic anterior uveitis (AU), other uveitis entities, and noninflammatory controls. Statistical biomarker identification was performed using the SELDI-ToF Biomarker Analysis Cluster Wizard followed by multivariate statistical analysis. Biochemical identi RESULTS. In the JIA group, one AH protein peak at mass/charge (m/z) 13,762 had qualitative and quantitative differences in expression compared with the other uveitis entities and the controls, but not to the group of silent chronic AU. Its quantitative expression in AH of patients with JIA and other silent chronic AU was positively associated with uveitis activity. The protein at m/z 13,762 in AH was identified as transthyretin (TTR). The TTR concentration in AH differed significantly between th CONCLUSIONS. TTR is a potential intraocular biomarker of JIA-associated uveitis. Its role in the pathogenesis of silent chronic AU with and without arthritis needs further investigation.