[A new method of functional assay of des-gamma-carboxyprothrombin using staphylocoagulase. Application to the diagnosis of hepatocellular carcinoma].

A new method to assay des-gamma-carboxyprothrombin (DCP) activity is described, using staphylocoagulase on undiluted citrated plasma after adsorption with bentonite (to remove fibrinogen), then with aluminium hydroxide. The thrombin-coagulase which is formed is measured by following the increase in optical density per minute of a chromogenic substrate. The results are expressed in milliunits (m.U.). The new method is sensitive and specific. It confirms the usefulness of the DCP assay for the diagnosis of hepatocellular carcinoma (Liebman et al.). Ninety-six normal subjects had levels of DCP ranging from 0 to 12 m.U. Out of 42 patients with hepatocarcinoma, 30 (71%) had DCP levels higher than 15 m.U. The increased DCP appears to be complementary to alpha-foetoprotein, since one or the other marker were positive in 37 out of 40 cases (92.5%) of hepatocellular carcinoma. Chronic hepatitis or cirrhosis (36 cases) and non-hepatocellular liver cancer (9 cases) gave normal DCP values.