title: The use of a functional and immunologic assay for plasma protein C in the study of the heterogeneity of congenital protein C deficiency.
abstract: Protein C is a vitamin K dependent protein involved in blood coagulation. A congenital deficiency in protein C antigen - which inherits as an autosomal dominant disorder - has been reported to be associated with a high risk for thrombo-embolic disease at relatively young age. In the present paper we report on the development of a functional assay for plasma protein C. In this assay protein C is adsorbed to Al(OH)3, eluted and activated by thrombin, after which the concentration of the activated protein C is measured with a peptide substrate (S2366). Normal values for protein C activity and protein C antigen were determined in healthy volunteers and patients on stable oral anticoagulant treatment. Protein C activity and antigen levels were compared in 28 patients from 9 different pedigrees with both congenital protein C deficiency and thrombotic disease. Two types of protein C deficiency could be recognized: in type I the deficiency is due to the absence or reduced presence of protein C molecules, while in type II the deficiency is caused by the presence of an abnormal protein C molecule with strongly reduced functional activity.
mesh_terms: D000328:Adult; D000941:Antigens / Q000032:analysis; D001779:Blood Coagulation Factors / Q000032:analysis*; D005260:Female; D006023:Glycoproteins / Q000032:analysis* / Q000276:immunology; D006801:Humans; D008297:Male; D008722:Methods; D011486:Protein C; D013923:Thromboembolism / Q000097:blood / Q000151:congenital* / Q000188:drug therapy; D014812:Vitamin K / Q000037:antagonists & inhibitors
chemical_list: D000941:Antigens; D001779:Blood Coagulation Factors; D006023:Glycoproteins; D011486:Protein C; D014812:Vitamin K