Overshoot of FVIII activity in patients with acquired hemophilia A who achieve complete remission
Acquired hemophilia A (AHA) is a rare, life-threatening bleeding disorder caused by autoantibodies against coagulation factor VIII (FVIII). Immunosuppressive therapy for AHA aims to arrest bleeding by eliminating FVIII inhibitors. Factor VIII activity overshoot after complete remission (CR) has been reported anecdotally, but details remain unclear. We retrospectively analyzed data from 17 patients with AHA who achieved CR under immunosuppressive therapy between 2009 and 2019 at Gunma University Hospital. FVIII activity overshoot was defined as ≥ 150%. All 17 patients had low FVIII activity (median 2.1%; range < 1.0–8.9%) due to FVIII inhibition (median 14.7 BU/mL; range 2.0–234.0) and all achieved CR within a median of 39 (range 19–173) days. Overshoot occurred in 11 (64.7%) patients and maximal FVIII activity reached > 200% in six of them. The median duration from CR to overshoot was 13 (range 0–154) days. The FVIII overshoot was transient (72.7%) or persistent (27.3%). Venous thromboembolism developed as a complication of overshoot in one patient due to iliac vein compression by a massive hematoma. Overshoot of FVIII activity after CR occurs more frequently than previously expected in patients with AHA.
KeywordsAcquired hemophilia A Coagulation factor VIII (FVIII) FVIII inhibitor Overshoot of FVIII activity Immunosuppressive therapy
We are grateful to the patients who participated in this study.
YO, AI, MI and HH designed the study. YO, KY, CN, HU, TI, HS, FG, and HH evaluated patients. YO, KY and CN analyzed the data. YO, AI and HH prepared the manuscript, which all the authors reviewed.
Compliance with ethical standards
Conflicts of interest
None of the authors have any conflicts of interest to declare.