Anti CD20 (Rituximab) therapy in refractory pediatric rheumatic diseases

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.

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.

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.

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.