Novel treatment strategies for acquired hemophilia A

Abstract

Acquired hemophilia A (AHA) is a bleeding disorder caused by autoantibody (inhibitor) production targeting blood coagulation factor VIII (FVIII). It is characterized by sudden onset, and often causes extensive and severe bleeding in soft tissue. Acquired hemophilia A is diagnosed when coagulation tests show normal PT, prolonged APTT, decreased FVIII activity, normal VWF activity, and positive FVIII inhibitor. Hemostatic therapy mainly consists of bypass therapy, which activates the extrinsic coagulation pathway, bypassing the need for FVIII or factor IX. Emicizumab, a bispecific antibody that substitutes for FVIII function, can be used to prevent bleeding. Immunosuppressive therapy is necessary to suppress or eradicate inhibitors. The majority of patients go into remission with treatment, but some die from bleeding symptoms or infections associated with immunosuppressive therapy.