Studies were made on the effects of administration of human antihemophilic globulin preparation (HAHG) upon coagulation defects of patients with hemophilia A. HAHG was a Cohn fraction I, obtained from a smallest pool of fresh normal plasma by the method of Nitschmann, Kistler and Joss, by the courtesy of Dr. Naito, MIDORI-JUJI Co. One dose of HAHG was prepared from 200 ml. of fresh normal ACD-plasma, for clinical use one dose of HAHG was dissolved into 100 ml. of Aq. dest.
Assay of 150 HAHG samples demonstrated 158±23.6%, about twice as much factor VIII as in normal plasma and also about twice as much fibrinogen (680±135 mg/dl). Negligible amounts were found in prothrombin, factor V, factor VII-complex, factor IX and factor X.
At various intervals after a single infusion of 100 ml. of HAHG to a patient with hemophilia A, determinations were made on factor VIII, fibrinogen, clotting time and serum prothrombin in paient blood. The infusion invited normalization of clotting time and prothrombin consumption as well increase of factor VIII for eight hours, while a slight increase (about 100 mg/dl.) of fibrinogen lasted for four hours.
The half life of factor VIII was estimated to be five hours, when a single dose of HAHG or 100 ml. of fresh normal plasma was given to patients with hemophilia A. Following a single dose infusion of HAHG, there developed a two-phase logarithmic diappearanse curve which consisted of an initial rapid phase and a second slower phase.
The factor VIII level reached a peak at 30 minutes after infusion of HAHG to patients with hemophilia A. This rise in factor VIII consentration ranged from 4 to 40 per cent when various doses of HAHG or fresh normal plasma ranging 2u/kg to 20u/kg were infused, which was almost equivalent to the expect one, and it was calculated that this observed rise after infusion of 1u/kg was about 2 per cent.