Alpha 2-antiplasmin (orα2-antiplasmin orplasmin inhibitor) is aserine protease inhibitor (serpin) responsible for inactivatingplasmin.[5] Plasmin is an importantenzyme that participates infibrinolysis and degradation of various other proteins. This protein is encoded by theSERPINF2 gene.[6]
Fibrinolysis (simplified). Blue arrows denote stimulation, and red arrows inhibition.
Very few cases (<20) ofalpha-2-antiplasmin deficiency have been described. As plasmin degrades blood clots, impaired inhibition of plasmin leads to a bleeding tendency, which was severe in the cases reported.
In livercirrhosis, there is decreased production of alpha 2-antiplasmin, leading to decreased inactivation ofplasmin and an increase infibrinolysis. This is associated with an increased risk of bleeding in liver disease.[7] It has been suggested, however, that the observed decreases in alpha 2-antiplasmin levels are due to a chronic state ofdisseminated intravascular coagulation in cirrhosis rather than defective protein synthesis.[8]
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