Antihemophilic Factor (Factor VIII)

Publisher Website
Google Scholar
Abstract
Antihemophilic factor (Factor VIII) is an agent in normal plasma that corrects the coagulative defect of classic hemophilia. The plasma of [human] hemophiliacs contains normal amounts of a variant of antihemophilic factor deficient in clot-promoting properties. Von Willebrand''s disease is usually associated with a true deficiency of this protein. In this disorder, the platelets are poorly aggregated by ristocetin, a defect ascribed to deficiency of antihemophilic factor. Structural studies of antihemophilic factor suggest that it is composed of 2 dissociable subcomponents, 1 of high MW that contains the bulk of protein and sustains ristocetin-induced platelet aggregation, and another of lower MW with procoagulant activity. Both subcomponents were identified in hemophilic plasma, as if the smaller subcomponent were qualitatively abnormal. Carriers of hemophilia can often be detected because their plasmas contain a disproportionately high concentration of antihemophilic factor, measured immunologically, compared with the titer of procoagulant antihemophilic factor.
Keywords