antithrombiini

Antithrombin is a protein that plays a crucial role in the body's natural anticoagulant system. It is synthesized primarily in the liver and is a member of the serpin (serine protease inhibitor) superfamily. Antithrombin's main function is to inhibit the activity of several key clotting factors in the blood, most notably thrombin (factor IIa) and factor Xa. By neutralizing these factors, antithrombin prevents the formation of excessive blood clots.

The activity of antithrombin is significantly enhanced by heparin, a glycosaminoglycan. Heparin binds to antithrombin, causing a conformational change that dramatically increases antithrombin's ability to bind and inhibit its target proteases. This interaction is the basis for the therapeutic use of heparin and related drugs in preventing and treating thrombotic disorders.

Deficiencies in antithrombin can lead to an increased risk of developing blood clots, a condition known as thrombosis. These hereditary deficiencies are relatively rare but can have serious consequences. Conversely, acquired deficiencies can occur due to various medical conditions, such as liver disease or disseminated intravascular coagulation. Therapeutic administration of antithrombin concentrate is sometimes used to manage severe antithrombin deficiency or in specific clinical situations to reduce clotting risk.