Antihemophilic Factor (AHF) Levels Following Transfusions of Blood, Plasma and Plasma Fractions.

Abstract

Canine and human hemophiliacs were transfused with homologous blood or plasma. Increase in plasma AHF levels was proportional to the amount of AHF given. Over half the AHF activity disappeared within a few hours, although traces may persist for nearly a week. Frequent transfusions are required to maintain AHF at levels as high as 5-10% of normal. Potent plasma AHF fractions were injected into normal and hemophilic dogs. Half the injected AHF was lost in about 2 hours. The sensitivities of different tests for AHF were compared. AHF levels above 1% gave normal values for clotting time and prothrombin utilization tests. Levels above 15% gave normal values for the Partial Thromboplastin Time test. The AHF assay can be used for any values which are greater than 5% of normal.