What is antithrombin?

Updated: Feb 07, 2020
  • Author: Bishnu Prasad Devkota, MD, MHI, FRCS(Edin), FRCS(Glasg), FACP; Chief Editor: Eric B Staros, MD  more...
  • Print



A deficiency of antithrombin increases the risk of thrombosis, revealing its importance as a functional inhibitor of the blood coagulation proteases. Thrombin, factor Xa, and factor IXa are the primary proteases that antithrombin targets, [7, 8] with heparin increasing its inhibition of coagulation factors. Unless it is complexed to TF in the presence of heparin or cell surface glycosaminoglycans, factor VIIa resists being inhibited by antithrombin. [6]

The protease-serpin complex is cleared from the circulation by receptor-mediated endocytosis in the liver. [9] The antithrombin gene is found on the long arm of chromosome 1.

Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!