
Autoantibodies against factor VIII are rare but may cause life-threatening bleeding. Up to 30% of inhibitors may resolve spontaneously, but immunosuppressive drugs with possible serious adverse effects and costly factor replacement are usually required. Rituximab (Rituxan), a humanized monoclonal antibody against CD20-positive B cells, has been reported to be beneficial in certain antibody-mediated autoimmune diseases. We describe here four consecutively treated patients whose acquired factor VIII inhibitors responded rapidly to immunosuppressive regimens that included rituximab administered at 375 mg/m² weekly for 2 to 4 weeks.
