Analysis of hepatitis B genotype changes in chronic hepatitis B infection: Influence of antiviral therapy☆
Received 27 November 2007; received in revised form 13 March 2008; accepted 31 March 2008. published online 06 May 2008.
Background/Aims
The frequency of mixed hepatitis B virus (HBV) genotypes in chronic HBV (CHB) and genotype changes during natural disease evolution and as a result of antiviral therapy were investigated.
Methods
Serum samples from 103 CHB patients were included in a cross-sectional study. Longitudinal study of HBV genotypes was performed in 22 patients, 17 of them under antiviral therapy (lamivudine and/or adefovir). HBV genotyping was done by the INNO-LiPA HBV assay.
Results
Genotypes observed in the cross-sectional study: A 32% of cases, D 42%, C 2%, F 2%, and mixed genotypes 22% (mainly A/D, followed by A/G). Genotype G was found in 7% of patients, always combined with other genotypes. In the longitudinal study, genotype changes were observed only in treated patients (9 cases). Genotype A strains were positively selected in 6 of them, mainly as mixed A/D. In 6 patients, selection coincided with a decrease in HBV-DNA levels.
Conclusions
A high frequency of mixed HBV genotypes was observed in our setting. Selection of genotype A strains during treatment is likely an indication that sensitivity to therapy differs between genotypes A and D. The absence of changes in untreated patients suggests that HBV genotype is stable without external factors.
1Department of Biochemistry, Hospital General Universitario Vall d’Hebrón, Paseo Valle Hebrón s/n, Servicio de Bioquimica, Barcelona 08035, Spain
2Department of Hepatology, Hospital Universitario Vall d’Hebron, Barcelona, Spain
3Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Spain
Corresponding author. Fax: +34 93 2746831.
☆ The authors declare that they do not have anything to disclose regarding funding from industries or conflict of interest with respect to this manuscript.
ABSTRACT