Anti-B- cell-directed immunotherapy (rituximab) in the treatment of refractory pemphigus--an update.

Rituximab is a monoclonal antibody directed against the CD20 surface antigen present on B lymphocytes. Following its application, B cells are rapidly and specifically depleted. Rituximab has been approved for the treatment of relapsed and therapy-refractory non-Hodgkin lymphoma and has been incorporated into numerous chemotherapy regimes with promising results. Eradication of auto-reactive B cell clones is the rationale for its application in a variety of autoimmune disorders including the pemphigus group where B cells are thought to play a critical role in the pathogenesis. Preliminary reports in autoimmune disorders are encouraging. Adverse effects are generally well controlled and although severe infections have been reported following rituximab, the overall risk does not seem to be significantly increased. In the pemphigus group, rituximab has been successfully employed in refractory cases and a recent study suggests that a single course induces long-term remission in this patient group.