Elevated plasmin-α 2-antiplasmin complex levels in hereditary angioedema: Evidence for the [formula omitted] efficiency of the intrinsic fibrinolytic system

Abstract

The contact activation and fibrinolytic systems were assessed in 5 patients with hereditary angioedema (HAE). Reductions in F XII levels and increase in kallikrein-like activity in some patients indicated activation of the contact (intrinsic) system of coagulation. A great increase in plasmin-α 2-antiplasmin complex in all subjects indicated that in this disease, there is a constantly ongoing fibrinolysis. Since C1-inhibitor, the deficient protein in HAE, is a poor inhibitor of the well-known extrinsic (tissue-type) plasminogen activator, but the major inhibitor of the contact activation system and a related in vitro phenomenon termed intrinsic fibrinolysis, our data show that this fibrinolytic system is also sometimes operating efficiently in vivo . Furthermore, the known clinical data on HAE are compatible with a role of intrinsic fibrinolysis in the pathophysiology of this disease.