International recommendations on the diagnosis and treatment of acquired hemophilia A

Abstract

Acquired hemophilia A (AHA), a rare bleeding disorder caused by neutralizing autoantibodies against coagulation factor VIII (FVIII), occurs in both men and women without a previous history of bleeding. Patients typically present with an isolated prolonged activated partial thromboplastin time due to FVIII deficiency. Neutralizing antibodies (inhibitors) are detected using the Nijmegen-modified Bethesda assay. Approximately 10% of patients do not present with bleeding and, therefore, a prolonged activated partial thromboplastin time should never be ignored prior to invasive procedures. Control of acute bleeding and prevention of injuries that may provoke bleeding are top priorities in patients with AHA. We recommend treatment with bypassing agents, including recombinant activated factor VII, activated prothrombin complex concentrate, or recombinant porcine FVIII in bleeding patients. Autoantibody eradication can be achieved with immunosuppressive therapy, including corticosteroids, cyclophosphamide and rituximab, or combinations thereof. The median time to remission is 5 weeks, with considerable interindividual variation. FVIII activity at presentation, inhibitor titer and autoantibody isotype are prognostic markers for remission and survival. Comparative clinical studies to support treatment recommendations for AHA do not exist; therefore, we provide practical consensus guidance based on recent registry findings and the authors' clinical experience in treating patients with AHA.

Figure 1

Diagnostic pathway for acquired hemophilia A. The activated partial thromboplastin time (APTT) mixing study will not be needed in an environment in which factor VIII (FVIII) activity is immediately available. Note that the presence of lupus anticoagulant does not exclude acquired hemophilia A. See the ‘Diagnosis’ section for more details. FVIII:C: factor VIII activity; AHA: acquired hemophilia A; ELISA: enzyme-linked immunosorbent assay; rpFVIII: recombinant porcine factor VIII.

Figure 2

Choice and monitoring of hemostatic therapy in acquired hemophilia A. rFVIIa, recombinant activated factor VII (eptacog alfa); APCC, activated prothrombin complex concentrate; rpFVIII: recombinant porcine factor VIII (susoctocog alfa), hFVIII, human (plasma-derived or recombinant) factor VIII; h: hour; d: day.

Figure 3

Recommendations regarding Immunosuppressive therapy in patients with acquired hemophilia A. Comparison of immunosuppressive therapy regimens recommended in the 2009 international recommendations by Huth-Kühne et al. the GTH study and the current paper. FVIII; factor VIII activity; BU: Bethseda unit; CTX, cyclophosphamide.