Estimation of prothrombin in liver disease.

Prothrombin, both by a one- and a two-stage method, and progressive antithrombin were determined on the same plasma samples from 47 patients with cirrhosis and 27 patients with acute hepatitis. In the first group prothrombin estimated by the two-stage method was significantly higher than by the one-stage method. The values were often within the normal range and were not correlated with the indices of protein synthesis. Since progressive antithrombin was also depressed, the unduly high levels measured by the two-stage method are probably related to the influence exerted by antithrombin on the two-stage method. The opposite pattern was observed in patients with acute hepatitis, ie, the one-stage assay gave higher values than the two-stage assay. The one-stage method correlated better with the indices of protein synthesis. It is suggested that a one-stage assay should be used in patients with liver failure to evaluate the haemostatic balance before liver biopsy or surgery.