anti-thrombin IIIA 58-kD alpha2-glycoprotein with a single polypeptide chain that inactivates serine proteases (thrombin and other coagulation proteins, including factor Xa, IXa, kallikrein and others) by an irreversible heparin-dependent reaction.
AT-III dissolves blood clots that normally form within the circulation; heparin’s anticoagulant activity hinges on activation of AT-III. Decreased AT-III may be a congenital AD condition or acquired, occurring in DIC (due to pulmonary tuberculosis) or in liver disease (due to decreased AT-III production), resulting in an increased risk of coagulation.
0.15–0.45 mg/mL, or > 50% of lab’s control value.
Acute hepatitis, post-renal transplant, inflammation, menstruation, vitamin K deficiency.
Congenital deficiency, liver transplant, DIC, nephrotic syndrome, cirrhosis, chonic liver disease, carcinoma, mid-menstrual cycle; AT-III is defective in 0.14% to 0.5% of the general population.