Tissue factor pathway inhibitor (TFPI).

Tissue factor pathway inhibitor (TFPI) is a plasma proteinase inhibitor. It is a 42 kD glycoprotein that consists of 276 amino acid residues which sequence is known. TFPI is synthesized by vascular endothelial cells and part of it is associated with glycosaminoglycans of these cells. In blood TFPI is found in a free-form (active) and in an associated with lipoprotein form (nonactive). TFPI directly inhibits activated factor Xa and then factor VIIa/TF complex. Decreasing TFPI activity facilitates an activation of blood coagulation and fibrin forming, increasing TFPI activity inhibits these processes.