Rituximab use in young adults diagnosed with juvenile idiopathic arthritis unresponsive to conventional treatment: report of 6 cases.

Juvenile idiopathic arthritis (JIA) is the most common rheumatic disease in childhood. Without an effective therapy, patients may progress quickly to functional disability. Recently, depletion of B cells emerged as a new approach for the treatment of autoimmune diseases, including JIA. We describe six cases of JIA patients followed at a referral center for Rheumatology and Pediatric Rheumatology, submitted to treatment with rituximab (RTX) after refractoriness to three anti-TNF agents. Patients received RTX cycles with two infusions every six months. Response to treatment was assessed by DAS28, HAQ/CHAQ, and an overall assessment by the doctor and the patient. Of our six patients, four were girls (mean age at onset of disease: 6.1 years; mean disease evolution time: 15.1 years; mean age upon receiving RTX: 21.6 years). Four patients belonged to polyarticular subtype (1 rheumatoid factor [RF]-negative, 3 FR-positive), a patient with systemic JIA subtype with a polyarticular course and arthritis related to enthesitis. Of our six patients, five responded to treatment; and during the course of 12 months, the clinical response was maintained, although not sustained. However, discontinuation by infusion reactions caused the withdrawal of RTX in two patients. The use of RTX in JIA is restricted to cases refractory to other biological agents and, even considering that this study was held in a small number of advanced patients, RTX proved to be an effective therapeutic option.