F8 and autoimmune hemolytic anemia: In contrast allo-antibodies in congenital haemophilia A, where antibodies inactivate FVIII in first-order kinetics, the auto-antibodies in AHA tend to show a rapid initial inactivation phase followed by a slower phase of equilibrium in a non-linear inactivation pattern or type II kinetics where some factor VIII can usually be measured.6 The complex type II kinetics make it difficult to evaluate the clinical importance of the inhibitor titer level or the factor level.