antithrombin III

Antithrombin III is a naturally occurring plasma protein and the major endogenous inhibitor of thrombin and other serine proteases in the coagulation cascade, including factors IXa, Xa, XIa, XIIa, plasmin, and kallikrein. It is synthesized in the liver and circulates at a concentration of about 12.5 mg/dL in healthy adults. Antithrombin exerts its anticoagulant effect by forming an irreversible complex with thrombin via interaction between the active serine site on thrombin and an arginine reactive site on antithrombin. This process is greatly accelerated by heparin; thus, heparin’s therapeutic effect depends on sufficient levels of functional antithrombin[2][3][4][9]. Antithrombin III concentrates are used as replacement therapy for patients with hereditary deficiency to prevent or treat venous thromboembolism during high-risk situations such as surgery or childbirth[1][3][5]. There are both plasma-derived (e.g., Thrombate III) and recombinant (e.g., ATryn) formulations available.

Brand names

Thrombate IIIATryn

Other names

antithrombinantithrombin (human)human antithrombin IIIplasma-derived antithrombin III