B cell therapy in rheumatology: current perspectives

In the recent years there has been a steady increase in the armamentarium of drugs that are available with the rheumatologists. More and more targeted therapies are reaching the clinic. This is a reflection of the improvement in understanding of the immunological basis of autoimmune disorders and availability of technologies to make targeted therapies. The role of B cells in perpetuating and maintaining immune responses is now better understood. This has triggered research into the development of biologics specifically targeting the B Cells. The latest drug that has reached the clinic is rituximab, a chimeric monoclonal antibody to the CD20 molecule on the surface of mature B cells. It has been approved for management of patients with moderate to severe rheumatoid arthritis (RA) in adults who have had inadequate response to one or more biologic therapies. The success of rituximab therapy is a proof of the fundamental role of B cells in autoimmunity. B cell targeted therapies are here to stay and many more agents targeting various aspects of B cell biology are under development. This article discusses the current concepts of B cell biology and how the B cells can be targeted. It also reviews the emerging therapeutic agents targeting B cells with special reference to the trials that lead to approval of rituximab for RA.