[Anti-B-cell Strategies in Vasculitides and Collagenoses]

B-cells play a central role in the pathogenesis of autoimmune diseases. As already discussed in other articles, besides the production of potentially pathogenic autoantibodies, B-cells may function as antigen-presenting cells, may induce T-cell activation and produce various cytokines. The feasibility of targeting B-cells in patients with severe and refractory autoimmune disorders, especially in patients with vasculitis or connective tissue diseases, has met growing interest among rheumatologists in recent years. The use of rituximab as a monoclonal antibody directed against CD20 positive B-cells has been reported in case reports and small patient series; however, these are hard to compare as different diseases are described and different doses and schedules of rituximab were used. It has to be considered that positive reports are more likely to be reported than patients who do not improve or experience side effects. Data on only a few indications from randomized, double-blind studies are available; however, even these results should be evaluated critically.