Clinical outcomes of tocilizumab therapy in polyarticular and systemic juvenile idiopathic arthritis: a single-center analysis (2018-2022)

This single-center retrospective study aimed to evaluate the safety and efficacy of Tocilizumab (TOC) in children with polyarticular (pJIA) and systemic juvenile idiopathic arthritis (sJIA) who exhibited inadequate responses to disease-modifying antirheumatic drugs (DMARDs) and biological modifiers (bDMARDs). Conducted at the Department of Pediatric Rheumatology, National Institute of Geriatrics, Rheumatology, and Rehabilitation in Warsaw, Poland, between 2018 and 2022, the study enrolled 29 patients diagnosed with JIA based on International League of Associations for Rheumatology (ILAR) criteria. The cohort comprised 13 sJIA and 16 pJIA patients, aged 2-18 years, receiving TOC treatment for 24 months. Safety and efficacy assessments included analysis of medical documentation, laboratory tests (CRP, ESR, WBC), and Juvenile Disease Activity Score (JADAS) 71 at baseline, 3, 6, 12, and 24 months post-treatment initiation. Significant reductions in CRP and ESR levels were observed within three months, with sustained improvement in JADAS71 scores over the 24-month treatment period. A substantial majority, 73.07% of patients, achieved inactive disease status or low disease activity, highlighting T0C's effectiveness. Adverse effects were manageable, predominantly involving mild to moderate infections, with no serious adverse events or instances of macrophage activation syndrome (MAS). The study also noted a steroid-sparing effect of TOC, with a reduction in glucocorticoid usage among the cohort. Tocilizumab demonstrates substantial efficacy in reducing disease activity and improving clinical outcomes in patients with pJIA and sJIA, coupled with a favorable safety profile. These findings reinforce the role of TOC as a critical component of the therapeutic arsenal for JIA, offering hope for improved quality of life and disease management in this patient population.