Tear-based biomarker trajectories associated with uveitis in juvenile idiopathic arthritis: a multicenter prospective...

Extent of uveitis risk in juvenile idiopathic arthritis (JIA) is based on clinical factors. We aim to compare the trajectories of tear-based biomarker levels of patients with JIA with and without uveitis.

This prospective multicenter study included children with JIA at risk for uveitis (JIA-no-U), and with JIA-associated uveitis (JIA-U). Serial tear samples were collected from each eye by Schirmer strips at enrollment (E) and follow-up (FU1, FU2). S100 proteins, cytokines, and chemokines were assayed by Luminex or ELISA and compared between groups.

Fifty patients (37 JIA-no-U, 13 JIA-U) contributed 222 samples (150 JIA-no-U, 73 JIA-U). At E there were no significant differences in biomarker levels between JIA-U and JIA-no-U. During follow-up of JIA-U, monocyte chemoattractant protein-1 (MCP-1) levels increased longitudinally from E to FU1 and FU2 (1.63±0.31 to 2.46±0.31, p=0.005; and 2.89±0.32, p<0.0001), similar in Chemokine (C-X-C motif) Ligand (CXCL)-10 from E to FU1 and FU2 (4.39±0.41 to 5.26±0.41, p = 0.030; and 6.51±0.43, p < 0.0001) and in IL-8 levels from E to FU1 and FU2 (3.09±0.30 to 4.25±0.30, p = 0.006; and 4.65±0.32, p ≤ 0.001). In both groups, S100A12 and S100A8/A9 increased from E to FU.

Longitudinal changes in MCP-1, CXCL10 and IL-8 levels in tear fluid in JIA-U may reflect inflammatory ocular processes and support the role of monocytes and interferon related pathways in uveitis. Lack of differences in S100 proteins may reflect systemic inflammation from arthritis. Tear-based biomarkers may support clinical factors for identifying children with JIA who develop uveitis.