Background and Objectives: Genotype changes have been observed during long-term follow-up in adults with chronic hepatitis B virus (HBV) infection. The aim of this study was to assess the frequency and distribution of HBV genotype shifts in treated and untreated European children during the different phases of chronic hepatitis B.
Methods: The initial population consisted of 85 HBeAg-positive children who were sequentially investigated for HBV genotypes for a mean period of 7.1 years. During the survey, 65 patients seroconverted to anti-HBe and 24 received antiviral treatment. Genotyping was done by restriction fragment length polymorphism.
Results: Genotypes at enrollment were distributed as follows: D (n = 67), A (n = 11), B (n = 4), and C and mixed (n = 3). A genotype change was observed in 16 (19%) participants at last visit, of whom 1 of 20 (5%) remained persistently HBeAg positive and 15 of 65 (23%) children had seroconverted to anti-HBe (P < 0.001). The genotype shift was D to A or B in 9 individuals, A to D in 5, and A to B in 1. Genotype changes were more frequent in untreated than in treated subjects; however, the difference was not statistically significant.
Conclusions: The results of this study suggest that genotype change is a relatively frequent event in children with chronic hepatitis B after anti-HBe seroconversion and independent of treatment. The reasons why only some patients will experience this event remain to be clarified.