B-lymphocyte depletion therapy in rheumatoid arthritis and other autoimmune disorders.

B-lymphocyte depletion therapy is being explored in a wide range of autoimmune disorders. In many, there is early evidence for efficacy, and immunosuppression has not been a major problem. The mechanism of action is unclear, but appears to be consistent with the lowering of autoantibody levels, where relevant antibodies are quantifiable. An interesting finding is the persistence of clinical improvement for periods of 1 year or more after B-lymphocyte return, which supports the concept that stochastic generation of rare pathogenic B-lymphocyte subsets may be a rate-limiting step in pathogenesis.