A Treatment and Monitoring Protocol for Tocilizumab in Refractory Macrophage Activation Syndrome with Systemic Juvenile Idiopathic Arthritis

This study evaluated the therapeutic effectiveness and safety of tocilizumab (TCZ) in patients with systemic juvenile idiopathic arthritis (sJIA)-associated refractory macrophage activation syndrome (MAS). A total of 100 patients diagnosed between 2021 and 2022 were included. Patients receiving standard therapy (glucocorticoids plus cyclosporine A) were assigned to the control group (n = 30), while those receiving add-on TCZ were assigned to the study group (n = 70). The treatment protocol included intravenous methylprednisolone pulses followed by oral prednisone tapering, cyclosporine A with trough monitoring, and TCZ administered every 2 weeks. Outcomes included laboratory parameters, cytokine profiles (IL-6, IL-18, IFN-γ, sCD25, sCD163), sJADAS27 scores, clinical response, and adverse events over 24 months. The TCZ group demonstrated faster normalization of laboratory indices and greater reduction in inflammatory cytokines (P < 0.05). Remission rates were higher (71.4% vs. 33.3% at Day 14), with lower recurrence and reduced glucocorticoid exposure. Adverse event rates were lower in the TCZ group (25.7% vs. 46.7%, P < 0.05). These findings demonstrate that TCZ-based combination therapy provides an effective and well-tolerated salvage strategy for refractory sJIA-MAS and support further prospective evaluation of this protocol.