The temporal relationship between juvenile idiopathic arthritis disease activity and uveitis activity.

OBJECTIVE To determine whether there is a temporal association between arthritis and uveitis activity among children with juvenile idiopathic arthritis-associated uveitis (JIA-U). METHODS Uveitis and arthritis data from JIA-U patients ≤21 years were collected from 7/2013-12/2019 at a tertiary care center. Arthritis activity was assessed at each rheumatology visit, and the primary outcome was the presence of active uveitis at ophthalmologic exams within 45 days of the rheumatology visit. Repeated measures logistic regression was used to evaluate the temporal association between any uveitis activity within 45 days of arthritis activity. Models were adjusted for demographic, disease, and treatment-related factors. RESULTS Ninety eight patients were included; 81 (82%) female, 67 (69%) anti-nuclear antibody positive, 59 (60%) oligoarticular and 13 (13%) enthesitis related arthritis (ERA) subtypes. There were 1229 rheumatology visits with a median of 13 visits per patient (interquartile range 7 - 18). Concordance between arthritis and uveitis activity was observed 73% (694/947) of the time. There was an independent temporal association between uveitis and arthritis activity, odds ratio (OR) 2.47 [95% confidence interval 1.72, 3.54; p<0.01], adjusted for demographic and disease characteristics. Use of combination biologic and non-biologic disease modifying anti-rheumatic drugs, female sex, HLA-B27 positivity, ERA and polyarticular (RF-) subtypes were associated with decreased odds of active uveitis at any time point. CONCLUSION In patients with JIA-U, there is a significant temporal association between arthritis and uveitis disease activity. These novel results suggest that an arthritis flare should prompt an expedited referral to the ophthalmologist.