Prevalence and type of precore hepatitis B virus mutants in hepatitis D virus superinfection and its clinical implications.

To study the prevalence and type of the hepatitis B e antigen (HBeAg)-negative mutant in hepatitis D virus (HDV) superinfection, the precore region of hepatitis B virus (HBV) was analyzed by cycle sequencing. Of the 58 samples sequenced, 24 were wild type and 34 carried mutants. The precore stop mutation (TAG) at the 28th codon was found in 32 cases, other mutations were found in 7, and double mutations were found in 5. The absence of HBeAg showed a substantial agreement with the presence of mutants (kappa value, 0.74). Of the acute hepatitis patients, HDV replication and clinical manifestations were not significantly different between those with mutant and wild type virus, except that those with mutant virus were older (mean age, 48 vs. 28 years; P < .002). The absence of HBeAg in these patients is mainly due to HDV superinfection in older HBV carriers who already had precore mutant.