Comprehensive study into the activation of the plasma enzyme systems during attacks of hereditary angioedema due to C1-inhibitor deficiency

Abstract

Background: The activation of plasma enzyme systems contributes to hereditary angioedema attacks. We aimed to study the activation markers of the fibrinolytic, coagulation, and contact systems in a larger number of paired samples obtained from the same C1-INH-HAE patients in symptom-free periods and during attacks. Methods: Eleven parameters (Factors XI, XII, and C1-inhibitor activity; the concentrations of the D-dimer, prothrombin fragments 1∈+∈2, plasminogen, plasminogen activator inhibitor-1 [PAI-1], thrombin-anti-thrombin III [TAT] complex, fibrinogen) were measured along with prothrombin time and activated partial thromboplastin time (aPTT), using commercial kits. We compared these markers in samples obtained from the same 39 patients during attack-free periods and during 62 edematous episodes. Forty healthy subjects of matching sex and age served as controls. Results: Compared with the healthy controls, significantly higher FXI and FXII activity (p∈=∈0.0007, p∈=∈0.005), as well as D-dimer (p∈