The enduring role of sulfasalazine in the treatment of juvenile idiopathic arthritis: a retrospective cohort study on safety and effectiveness

Abstract

Sulfasalazine (SSZ) is a commonly used disease-modifying antirheumatic drug for juvenile idiopathic arthritis (JIA) that is primarily recommended within the group of juvenile spondyloarthropathies. Current treatment guidelines increasingly limit its role in the management of JIA. This study aimed to evaluate the effectiveness, tolerability and predictive factors of SSZ response in children with JIA, focusing on the impact of ILAR and PRINTO classifications and specific clinical characteristics. This is a multicenter retrospective cohort study of 70 children (≤ 16 years) with JIA treated with SSZ. Effectiveness was assessed by rates of inactive disease, remission and clinical remission off medication. Tolerability was evaluated by the incidence and nature of adverse events. Univariate and multivariate logistic regression analyses were used to identify predictors of SSZ remission, including ILAR and PRINTO categories, polyarticular disease, axial disease and hip involvement. SSZ induced inactive disease in 70% of patients and remission in 47.1%, with 12.9% achieving clinical remission off medication. Adverse events occurred in 24.3% of patients, leading to SSZ cessation in 20%, primarily involving abdominal complaints. Univariate logistic regression analysis showed no significant differences in remission rates between ILAR and PRINTO subgroups. However, patients with persistent oligoarthritis had a significantly increased likelihood of remission (OR 4.7) compared to the overall cohort. The absence of polyarticular disease (OR 7.4), axial disease (OR 3.7) and hip involvement (OR 2.8) were significant predictors of remission. Multivariate analysis confirmed the association between remission and both the absence of axial (OR 3.3) and polyarticular disease (OR 7). This study reinforces the effectiveness of SSZ in JIA. SSZ demonstrated acceptable tolerability in this cohort. Clinical characteristics, such as the absence of polyarticular and axial disease and hip involvement, appear to be more significant predictors of treatment response than ILAR or PRINTO classifications. Given the observed lower likelihood of remission in patients with axial disease, all of whom had sacroiliitis in this cohort, a more rapid transition to biologicals may be warranted in such cases. SSZ appears to be a viable treatment option, especially for persistent oligoarthritis, however cautious interpretation is warranted due to the retrospective design.