C1 Esterase Inhibitor
C1-Inhibitor (C1-INH, C1 esterase inhibitor) is a protease inhibitor belonging to the serpin superfamily. Its main function is the inhibition of the complement system to prevent spontaneous activation. C1-inhibitor is an acute-phase protein that circulates in blood at levels of around 0.25 g/L. The levels rise ~2-fold during inflammation. Although named after its complement inhibitory activity, C1-inhibitor also inhibits proteases of the fibrinolytic, clotting, and kinin pathways. C1-inhibitor is the most important physiological inhibitor of plasma kallikrein, FXIa, and FXIIa.
TECHNOCHROM® C1-Inhibitor is a reagent kit for the chromogenic determination of C1 esterase inhibitor (C1-INH). Defect in the synthesis of C1-INH leads to hereditary angioedema.