Letters to the Editor Hepatitis B viral genotypes and lamivudine resistance

lamivudine treatment was 12 months for genotype B patients and 11 months for genotype C patients. Consecutive blood samples were collected from each patient every 3 months or shorter when clinically indicated. HBV DNA extracted from serum samples with biochemical and/or virological breakthroughs was amplified and then sequenced for lamivudine resistance-associated mutations. Overall, three of 13 patients (23%) with genotype B infection and two of 18 (11%) with genotype C infection had seroconversion from HBeAg to anti-HBe, but none had lost HBsAg. Meantime, lamivudine resistance occurred in six patients (19%), two (15%) from genotype B group and four (22%) from genotype C group (P ¼ 0:9), after a mean duration of 9 months (range 8‐13 months). Other factors including gender, body mass index, pretreatment serum alanine aminotransferase and HBV DNA level were analyzed in our patients but showed no significant association with the development of lamivudine resistance. Our data suggested that HBV genotype B seems to have a better virological response to lamivudine as compared to genotype C in Taiwan; however, both genotypes have a similar risk in developing lamivudine resistance after 1 year of therapy. Nevertheless, the influence of genotype on the development of lamivudine resistance might be more obvious after a longer-term treatment. Although HBV genotype has been suggested as a variable in further therapeutic trials for chronic hepatitis B [4], whether a modified treatment regimen should be considered for chronic hepatitis B patients with different genotypes awaits further prospective studies.