Behavior of factor VIII associated antigen in thrombophilic states

: In several diseases the factor VIII: Ag in the plasma of patients increases extremely in some cases, while the other subunits of the factor VIII molecule increase moderately. Only in very few cases these findings might be the expression of a thrombin-induced alteration of the factor VIII molecule. Determination of factor VIII: Ag in vascular diseases is of comparatively high clinical relevance, since in this case a high factor VIII: Ag level may be indicative of endothelial lesion, if other influences can be ruled out.