Acquired coagulation inhibitors result from immune-mediated depletion or inhibition of a coagulation factor. Inhibitors are most commonly directed against factor VIII (FVIII) and von Willebrand factor (VWF) and inhibitors against other coagulation factors are only occasionally reported.

Since the publication of previous guidelines, substantial new data has been published on acquired FVIII inhibitors, necessitating updated guidelines. The rarity of acquired inhibitors to other coagulation factors means that limited information is available to guide management and the treatment strategies suggested are necessarily by consensus and often extrapolated from data derived from FVIII inhibitors.

Declaration of Interests

The BSH paid the expenses incurred during the writing of this guidance. None of the authors had conflicts of interest to declare. All authors have made a declaration of interests to the BSH and Task Force Chairs which may be viewed on request.