Hepatitis B e antigen in sera from individuals infected with hepatitis B virus of genotype G

Abstract

Hepatitis B virus (HBV) genotype G (HBV/G) was detected in sera from four individuals by polymerase chain reaction with hemi‐nested primers deduced from an insertion of 36 nt in the core gene that is specific for this genotype. Despite two stop codons in the precore region characteristic of HBV/G, all patients were positive for hepatitis B e antigen (HBeAg) in serum. When 10 HBV clones were propagated from one patient, and sequenced within precore region and a section of the core gene, 6 clones were HBV/G while 2 were genotype A (HBV/A); a recombination between HBV/G and HBV/A occurred in the remaining 2 clones. Mixed infection of HBV/G and HBV/A, as well as the recombination, was demonstrated in the sequence of preS1 and preS2 regions also. Coinfection with HBV/G and HBV/A was demonstrated in the other three patients, and their recombination in two patients. Ten HBV clones were propagated from one patient at two time points separated by 1 year. Clones of HBV/A, HBV/G and their recombination were found in 9 : 1 : 0 when the patient was positive for HBeAg, while the proportion shifted to 0 : 8 : 2 after the patient seroconverted to anti‐HBe. In conclusion, HBV/G is frequently found as a coinfection with HBV/A. This coinfection would explain the presence of HBeAg in individuals infected with HBV/G. Along with seroconversion to anti‐HBe, HBV/G would be selected accompanied by the recombination with HBV/A. Further studies should be performed to confirm these findings.