Methotrexate therapy associated with a reduced rate of new-onset uveitis in patients with biological-naïve juvenile idiopathic arthritis

OBJECTIVE: To study the effect of methotrexate (MTX) therapy on new-onset uveitis in patients with biological-naïve juvenile idiopathic arthritis (JIA). METHODS: In this matched case-control study, we compared MTX exposure between cases with JIA-associated chronic uveitis (JIA-U) and patients with JIA and without JIA-U at the time of matching (controls). Data were collected from electronic health records of the University Medical Centre Utrecht, the Netherlands. Cases with JIA-U were matched 1:1 to JIA control patients based on JIA diagnosis date, age at JIA diagnosis, JIA subtype, antinuclear antibodies status and disease duration. The effect of MTX on JIA-U onset was analysed using a multivariable time-varying Cox regression analysis. RESULTS: Ninety-two patients with JIA were included and characteristics were similar between cases with JIA-U (n=46) and controls (n=46). Both ever-use of MTX and exposure years were lower in cases with JIA-U than in controls. Cases with JIA-U significantly more often discontinued MTX treatment (p=0.03) and out of those who did, 50% afterwards developed uveitis within 1 year. On adjusted analysis, MTX was associated with a significantly reduced new-onset uveitis rate (HR: 0.35; 95% CI: 0.17 to 0.75). No different effect was observed between a low (<10 mg/m2/week) and standard MTX dose (≥10 mg/m2/week). CONCLUSION: This study demonstrates an independent protective effect of MTX on new-onset uveitis in patients with biological-naïve JIA. Clinicians might consider early initiation of MTX in patients at high uveitis risk. We advocate more frequent ophthalmologic screening in the first 6-12 months after MTX discontinuation.