Thrombin-Antithrombin Complex Unit Converter

Thrombin-Antithrombin Complex (TAT) is a molecule formed when thrombin, the key enzyme in blood clotting, binds to antithrombin III, one of the body's natural anticoagulants. Once bound together, the complex is inactive and is quickly cleared from the bloodstream by the liver.

Because thrombin itself is extremely short-lived in blood, it cannot be measured directly. TAT serves as an indirect marker of thrombin generation, meaning it tells clinicians whether the coagulation cascade has been activated recently.

TAT has a very short plasma half-life of roughly 3 to 15 minutes, so an elevated level reflects active or very recent clotting rather than a past event.

TAT forms in the bloodstream whenever the coagulation cascade generates thrombin. Thrombin is produced from its precursor prothrombin at sites of vascular injury, while antithrombin III is synthesized primarily by the liver and circulates continuously in the plasma as a natural anticoagulant.