Alpha2antiplasmin

Alpha-2 antiplasmin (α2-antiplasmin) is a plasma glycoprotein and the principal physiological inhibitor of plasmin, the enzyme responsible for fibrin degradation. It belongs to the serine protease inhibitor (serpin) family and is primarily synthesized in the liver. By rapidly forming irreversible complexes with plasmin, alpha-2 antiplasmin limits fibrinolysis and contributes to clot stability; a fraction is covalently cross-linked into forming fibrin clots by activated factor XIII, enhancing resistance to enzymatic breakdown.

Physiologically, alpha-2 antiplasmin helps maintain the balance between clot formation and dissolution, preventing premature clot lysis while allowing normal fibrinolytic clearance when appropriate. Levels and activity can be assessed by specific antigen and functional assays in clinical laboratories.

Clinically significant abnormalities include congenital deficiency, a rare inherited disorder that predisposes to bleeding due to uncontrolled fibrinolysis, and acquired reductions in alpha-2 antiplasmin seen in conditions such as severe liver disease, disseminated intravascular coagulation, or after intensive thrombolytic therapy. Therapeutic approaches to manage hyperfibrinolysis often use antifibrinolytic agents and supportive blood products; conversely, modulation of alpha-2 antiplasmin activity has been explored in research on thrombosis and wound healing.