Immunoadsorption in the treatment of acquired haemophilia

Abstract

In acquired haemophilia (AH) healthy humans can suddenly develop severe bleeding due to autoantibodies (inhibitors) against clotting factors, especially factor VIII. The mortality rate of 21 % is considerable, and standardized treatment protocols have not been developed due to the low disease frequency (1-4 per million). Major goals of treatment are the control of bleeding events and rapid inhibitor elimination. Conventional treatment regimens induce immune tolerance via long-term immunosuppression with success rates between 52% and 82%. However, treatment related mortality can rise to 39%. Lack of complete remission, advanced age, underlying malignancies and infections related to immunosuppressive therapy are regarded as principal risk factors for death. The modified Bonn-Malmö Protocol (MBMP), an immune tolerance protocol consisting of antibody depletion through immunoadsorption, i.v. immunoglobulin treatment, immunosuppression and high dose FVIII supplementation, achieves rapid and safe control of acute bleeding. In the largest published single centre study of high risk patients with AH, we previously demonstrated that complete remission (CR) can be achieved in 88.5% of all patients (54/61) within a median time of 3.9 wks (range: 3.2-4.5 wks) and in 97% (54/56) of AH patients without cancer as an underlying condition. Those 5 patients, who suffered also from cancer, achieved partial remission (PR). Mortality or severe treatment-related side effects were not observed. This study confirmed that MBMP is a safe and effective treatment with a high curative potential for severe AH. However, the severity of bleeding, and therefore the cost-effectiveness of the approach, needs to be considered when initiating this treatment protocol.