Long term treatment of rheumatoid arthritis with rituximab.

B cells play an important role in the pathogenesis of rheumatoid arthritis (RA). Rituximab is a chimeric monoclonal antibody that depletes B-cells by binding to the CD20 surface antigen that has been approved for the treatment of RA. Its efficacy has been clearly demonstrated by different clinical trials and, recently, in long-term observational studies. The use of rituximab in clinical practice has highlighted its efficacy and safety over more than 5 years of treatment, as well as to try to understand the timing for retreatment of patients relapsing after a good initial response.