“Accelerator Globulin” and “Antihemophilic Globulin” in Thrombin Formation from Aged Prothrombin and in Hemophilic Blood. ∗

Abstract

Conclusions

1. There is a new factor, or group of factors, (Quick's “labile factor” Owren's “factor V,” Ware, Guest and Seegers' “accelerator globulin”), to be recognized in the first phase of the blood-clotting system. At present it may be considered an “accessory” activator distinct from calcium, thromboplastin, and thromboplastic enzyme. 2. This factor is found abundantly in fresh plasma and prothrombin (purified by the usual methods, e. g. 13 ), but deteriorates on “aging,” independently of the prothrombin. High dilution may be necessary to demonstrate this. The addition of fresh AcG will restore the original potency of the prothrombin, but aged AcG loses this property. 3. AcG is not “antihemophilic” and so-called “antihemophilic globulin” is not able to restore the activity of aged prothrombin. 4. “Owren's disease,” 18 a specific hemorrhagic disorder associated with a plasma deficiency of this new factor, is, in all probability, a true clinical entity, which suitable tests can differentiate from “idiopathic hypo-prothrombinemia,” hemophilia, and other bleeding diseases.