THROMBOPLASTIN GENERATION ACCELERATOR, A NEWLY RECOGNIZED COMPONENT OF THE BLOOD COAGULATION MECHANISM PRESENT IN EXCESS IN CERTAIN THROMBOTIC STATES*

Abstract

A new component of the coagulation mechanism is described which is named thromboplastin generation accelerator, or TGA, and appears to be responsible for the accelerated formation of plasma thromboplastin observed in certain patients with intravascular thrombosis. It is a moderately heat-labile protein associated with the [beta]-globulins, present in fresh plasma but not in serum. Its site of action seems to be the initial stage of clotting, where it appears to influence primarily the rate of formation, and possibly the yield, of plasma thromboplastin. It is unaffected by therapy with coumarin drugs.