Prekallikrein is a vitamin K-dependent glycoprotein non-covalently complexed with high molecular weight kininogen. It participates in the activation of coagulation depending on the surface, in fibrinolysis, in the generation of kinins and in inflammatory phenomena.
The prekallikrein deficits prolong the activated partial thromboplastin time (TCA), which varies according to the reagents (significant lengthening with silica or kaolin), without modification of the other coagulation tests.
The TCA can be corrected by adding control plasma and in the absence of deficiency in FVIII, FIX, FXI, FXII.