The potential risk of infections during (prolonged) rituximab therapy in rheumatoid arthritis.

INTRODUCTION: Biologicals are a fast expanding group of new drugs and rituximab (RTX) is one of them. Long-term efficacy and safety constantly need addressing as little is known about these factors. In rheumatoid arthritis, RTX it is used for active disease that is not responding to other therapies. Since RTX acts by depleting B-cells, concerns regarding the long-term safety of this drug have been raised. AREAS COVERED: This review covers 10 manuscripts on RTX safety in rheumatoid arthritis published between January 2004 and July 2010. EXPERT OPINION: In present literature RTX appears to be safe for up to five courses. In this review, important drawbacks of current research are discussed. Longer follow-up time is needed to make relevant conclusions on RTX safety with regard to infectious complications. Prolonged RTX therapy causes subsequent B-cell depletion. Eventually, plasma cells disappear, causing hypogammaglobulinemias and subsequent problems in immunity. The formation of new plasma cells is halted due to a lack of B-cells. Attention needs to be focused on the status of immunoglobulins and the role this plays in the occurrence of infections. Until a complete, long-term safety profile of RTX is available, it cannot be considered safe with regard to the incidence of infectious complications.