Antihemophilic factor levels in bleeder swine following infusions of plasma and serum

Swine with a hemophilia-like disease characterized by a long bleeding time and low antihemophilic factor (AHF, factor VIII) level were infused with porcine plasma and porcine serum. Unlike the response of classical hemophiliacs, but similar to that of patients with von Willebrand's disease, the initial postinfusion levels of AHF were sustained with some fluctuation for 24 hr. Serum infusion resulted in a delayed increase in AHF which reached a maximum concentration between the 12th and 24th hr after infusion. Within 75 hr the effects of both the plasma and serum infusions had vanished. No correction of the prolonged bleeding times was observed following the infusions. The AHF levels encountered after the infusion of plasma and serum cannot be accounted for by the AHF activity contained in the infused materials; new AHF synthesis or AHF release from storage are suggested as possible mechanisms.