Fulminant or subfulminant liver failure, complicated by encephalopathy and in many cases by death is seen to be a syndrome that may result from numerous causes. Although viral hepatitis, drug-induced hepatitis, and hepatitis due to various types of poisonings, in decreasing frequency, account for 90% of all cases, a variety of miscellaneous conditions account for the remainder. Consideration of the possibility of these less common etiologies by the clinician is of considerable importance, since some, including massive malignant involvement (such as leukemia) or acute fulminant Wilson's disease, may respond to specific treatment measures. Thus, unless hepatic transplantation proves to be applicable in FHF of many etiologic diagnosis may continue to have important therapeutic indications in at least some cases with this syndrome.

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.