Serum Accelerator Factors and Antihemophilic Factor (AHF) in Early Phases of Clotting.

Abstract

Some of the relationships of the antihemophilic factor (AHF) and the serum accelerators in dog blood are described. Serum factors designated SA, are those which are adsorbed on to BaSO4 and eluted by sodium citrate. The eluate (SA) probably contains both convertin (SPCA) and PTC (Christmas factor). It was shown that the eluate markedly shortened the clotting time of hemophilic blood and plasma without correcting the fundamental defect in prothrombin utilization. It was shown further that the chief action of the eluate was in reducing the latent period of the prothrombin-to-thrombin reaction, without greatly increasing the rate of prothrombin conversion. An apparent synergism between the SA and the AHF was noted; the importance of this synergism in introducing errors into AHF assays and the prothrombin time determination was discussed.