Leflunomide is associated with a higher flare rate compared to methotrexate in the treatment of chronic uveitis in juvenile idiopathic arthritis

Objectives: Chronic anterior uveitis is a serious complication of juvenile idiopathic arthritis (JIA); disease flares are highly associated with loss of vision. Leflunomide (LEF) is used successfully for HA joint disease but its effectiveness in uveitis has not been determined. The aim of this study was to determine whether LEF improves flare rates of uveitis in HA patients compared to preceding methotrexate (MTX) therapy. Method: A single-centre retrospective study of consecutive children with JIA and chronic anterior uveitis was performed. All children initially received MTX and were then switched to LEF. Demographic, clinical, and laboratory data, dose and duration of MTX and LEF therapy, concomitant medications and rate of anterior uveitis flares, as determined by an expert ophthalmologist, were obtained. Flare rates were compared using a generalized linear mixed model with a negative binomial distribution. Results: A total of 15 children were included (80% females, all antinuclear antibody positive). The median duration of MTX therapy was 51 (range 26-167) months; LEF was given for a median of 12 (range 4-47) months. Anti-tumour necrosis factor (anti-TNF-alpha) co-medication was given to four children while on MTX. By contrast, LEF was combined with anti-TNF-alpha treatment in six children. On MTX, JIA patients showed a uveitis flare rate of 0.0247 flares/month, while LEF treatment was associated with a significantly higher flare rate of 0.0607 flares/month (p = 0.008). Conclusions: Children with HA had significantly more uveitis flares on LEF compared to MTX despite receiving anti-TNF-alpha co-medication more frequently. Therefore, LEF may need to be considered less effective in controlling chronic anterior uveitis.