Acquired hemophilia A

Abstract

Acquired hemophilia A is a rare but severe autoimmune bleeding disorder, resulting from the presence of autoantibodies directed against clotting factor VIII. The etiology of the disorder remains obscure, although approximately half of all cases are associated with other underlying conditions. A prompt diagnosis and appropriate management enable effective control of this acquired hemorrhagic disorder: the aims of therapy are to terminate the acute bleeding episode and eliminate or reduce the inhibitor. The recent availability of bypassing agents, first activated prothrombin complex concentrates and then recombinant activated factor VII, has significantly reduced mortality during the acute phase of the disease in patients with high titer inhibitors. On another front, immunosuppressive therapy (corticosteroids and cytotoxic agents, alone or in various combinations) has resulted in long-term inhibitor suppression in up to 70% of the cases. Moreover, new therapeutic strategies (anti-CD20 monoclonal antibody and immune tolerance protocols) are very promising and may further improve the prognosis of acquired hemophilia A.