The factor VIII:C/VWF:Ag ratio as a useful tool to predict relapse in patients with acquired haemophilia A: A retrospective cohort study

Haemophilia. 2019 May;25(3):527-534. doi: 10.1111/hae.13752. Epub 2019 May 2.


Introduction: Acquired haemophilia A (AHA) is a rare autoimmune bleeding disorder caused by the presence of autoantibodies against coagulation factor VIII (FVIII). The mortality rate remains high. International recommendations define complete remission as undetectable inhibitor (<0.6 Bethesda Units [BU]) and normal FVIII activity (FVIII:C) that persists after immunosuppressive therapy stopped. For patients achieving remission, the risk of relapse reaches 20%. The risk factors for this relapse are not well known.

Aim: In this study, we examined the accuracy of the FVIII/W ratio (FVIII:C/von Willebrand Factor Antigen (VWF:Ag) ratio) to predict relapse in 64 consecutive patients with AHA.

Results: In this cohort, all patients had a very low FVIII/W ratio at the time of diagnosis, and this value progressively increased in the first weeks of immunosuppressive treatment. In our study, 9/55 (14%) did not achieve complete remission. Twenty-seven patients were followed long enough (more than a year) to show that in the 22 patients who did not relapse, the FVIII/W ratio remained durably normalized. By contrast, in the five patients who relapsed during follow-up, we noted either no normalization of the FVIII/W ratio, or a secondary decrease to an abnormal value of <0.7 after initial normalization. In all patients who relapsed, the ratio was the first abnormal biological result to be observed, always preceding changes in the activated partial thromboplastin time (aPTT), FVIII:C and anti-FVIII reappearance.

Conclusion: These data suggest that the FVIII/W ratio could be considered a sensitive biological marker to predict recovery and/or relapse in AHA.

Keywords: Von Willebrand factor; acquired haemophilia A; factor VIII.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Cohort Studies
  • Factor VIII / metabolism*
  • Female
  • Follow-Up Studies
  • Hemophilia A / blood*
  • Hemophilia A / diagnosis*
  • Humans
  • Male
  • Middle Aged
  • Prognosis
  • Recurrence
  • Retrospective Studies
  • von Willebrand Factor / metabolism*


  • von Willebrand Factor
  • Factor VIII