A new hepatitis B virus variant in a chronic carrier with multiple episodes of viral reactivation and acute hepatitis.

To examine whether there are HBV variants not yet described which cannot express HBe due to a mutation in the pre-C region, and, if they exist, whether they cause a particular course of infection and disease, we analyzed the HBV genomes of a HBs/anti-HBe positive chronic carrier who had several episodes of acute reexacerbations of chronic hepatitis with at least two viremic phases. Direct sequencing of the precore/core and the pre-S regions of the HBV sequences of both viremic phases amplified by the polymerase chain reaction revealed that they were very similar to each other but substantially divergent from published HBV genomes. Both virus populations contained a mutation in the first nucleotide of the pre-C translation initiation codon (AUG/CUG) which prevents HBeAg expression. These data demonstrate the existence of a new HBV variant which can enter a latent phase from which it can be reactivated with acute reexacerbation of liver inflammation.