Assay of des-gamma-carboxyprothrombin using staphylocoagulase. Application to the diagnosis of cellular hepatocarcinoma.

A new clotting method is described to assay des-gamma-carboxyprothrombin (DCP), using staphylocoagulase and adsorbed undiluted citrated plasma. The thrombin-coagulase formed was tested with a chromogenic substrate. The results were expressed in milliunits (m.u.). All 96 normal plasmas had less than 15 m.u. (mean 3.58 m.u.). Out of 56 non-hepatectomized cellular hepatocarcinomas, 40 had DCP levels between 20 and 420 m.u. (average between 40 and 60 m.u.); 71.4% of cellular hepatocarcinoma had an increased DCP and 90% were positive either in alpha-foetoprotein or in DCP. Ten cases of non-cellular hepatocarcinomas had normal DCP levels. We found no cases of cirrhosis or chronic hepatitis, whether active or persistent, with abnormal level of DCP. Out of 127 patients tested, no case was found with a high DCP and a low level of "total factor II", which could be interpreted as a vitamin K deficiency. Only one case of hepatocarcinoma had 25 m.u. of DCP and a low total factor II (20%) and 2 had less than 10% total factor II with no detectable DCP.