According to a recent hypothesis, venous thrombosis results from the concurrence of several factors. This hypothesis was assessed in patients with portal or hepatic venous thrombosis by simultaneously investigating most of the currently identified prothrombotic disorders, local precipitating factors, and other risk factors such as oral contraceptive use. Patients with a tumorous obstruction and patients with cirrhosis with portal vein thrombosis were excluded. The prothrombotic disorders that were investigated included classical and occult myeloproliferative disorders; antiphospholipid syndrome; protein C; protein S and antithrombin deficiency; factor V Leiden; factor II; and methylene-tetrahydrofolate-reductase gene mutations. We found 1 or several prothrombotic disorders and a local precipitating factor in 26 and 10 of the 36 patients with portal vein thrombosis, respectively; and in 28 and none of the 32 patients with hepatic vein thrombosis, respectively. We found a combination of prothrombotic disorders in 5 and 9 patients with portal and hepatic vein thrombosis, respectively, whereas such a combination is expected in less than 1% of asymptomatic subjects. Of the 10 patients with a local precipitating factor, 8 had a prothrombotic disorder. Of the 13 patients who use oral contraceptives, 10 had a prothrombotic disorder. We conclude that portal or hepatic venous thrombosis should be regarded as an index for 1 or several prothrombotic disorders, whether or not local precipitating factors or oral contraceptive use are found. Concurrence of prothrombotic disorders is more common than expected.

We assessed prognostic factors in 115 patients with serologically defined fulminant hepatitis B. The diagnosis in each case was based on the finding of IgM antibody to the hepatitis B core antigen in serum. Multivariate analysis showed that factor V level (p less than 0.001), patient's age (p = 0.001), absence of detectable HBsAg by radioimmunoassay (p = 0.06) and serum alpha-fetoprotein concentration (p = 0.07) were independent predictors of survival. The survival rate in the 21 patients in whom HBsAg was not detected was 47%, which was significantly higher than the survival rate of 17% observed in the 94 HBsAg-positive patients (p = 0.006). In patients with fulminant hepatitis B, the absence of HBsAg in serum as detected by radioimmunoassay has an independent, favorable prognostic value.