Rituximab therapy has a rapid and durable response for refractory cytopenia in childhood-onset systemic lupus erythematosus.

Abstract

Autoimmune thrombocytopenia (AITP) and hemolytic anemia (AIHA) are common in childhood-onset systemic lupus erythematosus (cSLE) and may be refractory to conventional therapies. Our objectives were to: (a) examine our experience; (b) determine the rate and durability of response to rituximab; and (c) evaluate its safety in our cSLE population with refractory cytopenias. We performed a single-center retrospective cohort study of cSLE patients with refractory AITP or AIHA treated with rituximab between 2003 and 2012. Outcomes included the time to complete clinical response, time to B-cell depletion, duration of response and time to flare. Adverse events were also analyzed. Twenty-four (6%) of 394 cSLE patients received rituximab for refractory cytopenia. The indication was AITP in 16 (67%), AIHA in five (21%) and both in three (13%) patients. The median (interquartile range (IQR)) time from cytopenia onset to rituximab therapy was 16 (7-27) months for AITP and 10 (2-29) months for AIHA. Complete response following the first course of rituximab occurred at a median (IQR) of 48 (14-103) days, only one patient failed to respond. Five (21%) patients had one or more flare episodes at 22 (15-27) months. Infusion reactions were rare and one infection with herpes zoster required hospitalization in the first 12 months. Three of four patients with low IgG levels prior to the first rituximab course developed persistent hypogammaglobulinemia, and three patients have required intravenous immunoglobulin replacement. Rituximab appears to be a well-tolerated, safe and long-lasting therapy for cSLE patients with refractory AITP and/or AIHA. Caution should be exercised when considering rituximab for patients with preexisting hypogammaglobulinemia.