Atypical spontaneous factor VIII inhibitor: specific diagnostics and therapy of acute bleeding

Differentiation of rapidly binding coagulation factor inhibitors from antiphospholipid antibodies is a challenge for the hemostaseologic laboratory, especially with respect to the different therapeutic consequences. Several immunological and functional assays for the diagnosis of these disorders have been proposed. Here we report the clinical and laboratory findings of a 65-year-old man who developed severe bleeding after a tooth extraction. The process leading to the diagnosis of a spontaneous atypical factor VIII inhibitor and the value of different laboratory tests are discussed.