Anti CD20 (Rituximab) therapy in refractory pediatric rheumatic diseases.

OBJECTIVES: We aim to report the efficacy and safety of rituximab (RTX) in patients diagnosed with juvenile systemic lupus erythematosus (JSLE) or juvenile idiopathic arthritis (JIA) refractory to conventional treatment.

METHODS: A retrospective review was made of all medical records of patients with JSLE or JIA treated with RTX between January 2009 and January 2015 in the Pediatric Rheumatology Unit of a central hospital.

RESULTS: Five patients, 4 with JSLE and 1 with extended oligoarticular JIA, received 10 cycles of RTX (23 infusions). The scheme of RTX frequently used was 750 mg/m2 two weeks apart. The median follow-up time after receiving the first cycle of RTX was 24 months (12 - 70). The four patients with JSLE were female (three caucasian and one black). The patient with JIA was a caucasian male. The median age at diagnosis was 10 years (16 months - 17years). The median evolution time until receiving RTX was 6 years (5 months - 15 years). Refractory class IV lupus nephritis was the most common indication for receiving RTX. Previous treatment to RTX included nonsteroidal anti-inflammatory drugs, disease-modifying anti-rheumatic drugs, immunosuppressive drugs and corticosteroids in all patients and anti-TNFα (etanercept) in the patient with JIA. It was possible to reduce the mean oral corticosteroid dose after RTX, ranging from 23 mg/day (20-25mg/day) before RTX to 11 mg/day (0-20 mg/day) at the last evaluation. Disease activity before RTX and at last evaluation also improved. The SLEDAI score, for JSLE, decreased from a median of 15, 5 (11 - 18) to 3 (0 - 6), and the JADAS-27 score, for JIA, also diminished from 40.4 to 3.5. Adverse events occurred in 2 patients, including delayed second dose after the diagnosis of cryptococcosis and respiratory tract infection with concomitant hypogammaglobulinemia needing of immunoglobulin replacement and antibiotic therapy.

CONCLUSIONS: Rituximab might have a role in the treatment of JSLE and JIA. However controlled studies and long term follow-up are needed to evaluate its safety and efficacy.