Rituximab in steroid-sensitive nephrotic syndrome: lessons from clinical trials

Idiopathic nephrotic syndrome is the most common chronic glomerular disease in children. A total of 80-90% of patients with childhood idiopathic nephrotic syndrome achieve remission with steroid therapy [steroid-sensitive nephrotic syndrome (SSNS)]. However, approximately 50% of children with SSNS develop frequently relapsing nephrotic syndrome (FRNS) or steroid-dependent nephrotic syndrome (SDNS). Children with FRNS or SDNS are usually treated with immunosuppressive agents, but 10-20% of children receiving immunosuppressive agents still show frequent relapses or steroid dependence during or after treatment, defined as complicated FRNS or SDNS. Rituximab, a chimeric anti-CD20 monoclonal antibody that was originally developed to treat patients with B-cell non-Hodgkin's lymphoma, is currently used for treating SSNS. In this review we highlight recent studies, mainly randomized controlled trials of rituximab for SSNS, including complicated and uncomplicated forms of FRNS or SDNS in children. We also discuss the effects of these studies on the management of patients suffering from these conditions.