B cell-targeted therapy in diseases other than rheumatoid arthritis.

There are now numerous case reports and small series using rituximab in autoimmune diseases. While these data must be interpreted with caution, they suggest that rituximab (RTX) may be a promising addition to the therapeutic armamentarium. In patients with refractory chronic idiopathic thrombocytopenic purpura, treatment with RTX was effective in inducing complete responses in a significant proportion of patients, and these responses were usually durable. RTX has also been shown to be effective and well tolerated in children with refractory autoimmune hemolytic anemia. In patients with IgM antibody-associated polyneuropathy, RTX improved muscle strength, and repeated treatments over 2 years were well tolerated. In several case series of patients with systemic lupus erythematosus, depletion of B cells during RTX therapy was associated with improvement in global disease activity. Based on these reports, further controlled studies are warranted to optimize RTX as monotherapy and to develop combination therapies in patients with refractory autoimmune diseases.