Relationship between viral load and genotypes of hepatitis B virus in children with chronic hepatitis B

Objective: We evaluated the prevalence and clinical significance of hepatitis B virus (HBV) genotypes in children with chronic hepatitis B. Methods: Hepatitis B virus genomes of 249 hepatitis Be antigen-positive chronic hepatitis B surface antigen carriers were genotyped based on restriction fragment length polymorphism. Genotypes were correlated with corresponding values for alanine aminotransferase levels, quantitative HBV DNA and histological findings. Results: One hundred and sixty-two boys and 87 girls (mean age, 7.2 years) were studied. Ninety-six percent were attributed to HBV genotypes A (32.5%) or D (63.5%). The remaining were classified as genotypes B, C, E and F. There was no significant difference in both alanine aminotransferase levels and histological findings among different genotypes. However, there was a clear association between very high HBV DNA levels and individuals with genotype D (P 0.006). Mean time follow-up of 3.6 years showed later anti-HBe seroconversion in patients with genotype D than in those with genotype A (58% vs 37%). Conclusions: Compared with children with genotype A, children with genotype D showed a significantly higher viral load. Inasmuch as a relationship exists between viral load and response to treatment in children infected through vertical transmission, children with genotype D have to be carefully monitored. Long-term studies are needed to determine whether these patients are at risk of a poorer outcome.