F8 and hemophilia: In case of reduced factor FVIII, AHA is highly likely and the antibody titer should be determined using the Nijmegen modification of the Bethesda assay.22 In contrast to antibodies occurring in patients with inherited hemophilia that follow type 1 kinetics, the kinetics of the FVIII antibodies in AHA may be different, that is, type 2 kinetics, which may influence the measurement of the titer of the AHA FVIII antibody.