Elevated levels of free tissue factor pathway inhibitor antigen in cases of disseminated intravascular coagulation caused by various underlying diseases

Tissue factor pathway inhibitor (TFPI) is primarily synthesized by vascular endothelial cells and is found in vivo in association with endothelial cel ls, lipoproteins, or in free form. Free TFPI is the most potent and importa nt type, because it is released from endothelial cells following an injecti on of heparin, or as a result of pathological stimuli. In order to study th e role of TFPI in disease, the concentration of free form TFPI was measured in the plasma of 114 patients suffering from disseminated intravascular co agulation (DIC), as the result of several underlying diseases. Plasma antig en levels of free TFPI were significantly higher even in those patients not exhibiting DIC than in normal healthy subjects. These levels were even hig her among patients exhibiting DIG, especially those with acute promyelocyti c leukemia or cancer, receiving continuous heparin drip infusions, A signif icant correlation was observed between the plasma antigen levels of free fo rm TFPI and those of fibrin/fibrinogen degradation products, and free form TFPI and plasmin inhibitor complex (r= 0.428, P < 0.0001 and r= 0.329, P < 0.0001, respectively) among 114 DIC patients. There were no significant dif ferences between the plasma levels of free TFPI in DIC patients with or wit hout multiple organ failure. It has been suggested that the plasma levels o f free TFPI are closely related to the levels of fibrinolysis occurring in DIC patients, although further study is required to clarify the degree to w hich TFPI is expressed by endothelial cells during DIG. Blood Coagul Fibrin olysis 12:1-8 (C) 2001 Lippincott Williams & Wilkins.