Association of a precore genomic variant of hepatitis B virus with fulminant hepatitis.

A variant of hepatitis B virus has been described recently in HBsAg+ Mediterranean patients who lack HBeAg and who have an unusual and severe form of chronic hepatitis. This variant is unable to produce HBeAg because of the presence of a novel translational stop codon at the end of the precore region of the genome. By direct sequencing of DNA, generated by the polymerase chain reaction, we have evaluated the association between infection with this variant and the fulminant course of hepatitis B. Eighteen patients with fulminant hepatitis B were studied. Of the 15 cases from whose serum viral DNA could be sequenced, the variant was found in the admission sera of 8 of 9 HBeAg- patients but in none of 6 HBeAg+ patients who had fulminant hepatitis B. Patients harboring the variant progressed more rapidly into hepatic encephalopathy, but those infected with the variant strain alone had a greater likelihood of survival than those infected with the normal strain or a mixture. The mutant strain may emerge spontaneously during fulminant hepatitis as occurs in chronic hepatitis B infection during seroconversion from HBeAg to antibody. Alternately, and perhaps less commonly, patients may be infected with the variant ab initio.