Use of rituximab in the antiphospholipid syndrome.

B cells are promising targets for treatment in autoimmune diseases. Rituximab, a chimeric anti-CD20 monoclonal antibody that depletes B cells, is approved for use in rheumatoid arthritis and is often used to treat refractory autoimmune thrombocytopenia. There is increasing interest in using rituximab in other autoimmune diseases, including the antiphospholipid syndrome. We reviewed the published clinical experience of rituximab use in patients with the antiphospholipid syndrome. Data are limited to case reports and small case series. In 19 of 21 reported cases, rituximab appeared to have a beneficial clinical effect. Antiphospholipid antibodies levels were significantly decreased in ten of 12 cases. Controlled clinical trials are needed to determine if rituximab is effective in the antiphospholipid syndrome.