Study on the correlation between BCP mutations、genotypes and HBV Lamivudine-resistant YMDD mutation in Heilongjiang province

Objective To investigate the correlation between BCP mutations,genotypes and HBV Lamivudine-resistant YMDD mutation in Heilongjiang province. Methods The HBV DNA in 245 sera samples were collected from chronic hepatitis B patients who had been treated with lamivudine.HBV genotypes and YMDD mutations were detected by multiplex PCR and FH-PCR-MC respectively.HBV C gene region was amplified by nest PCR,then BCP mutations were analyzed.Results There were no statistical differences for the ratio of genotype between YMDD wild type(8.8％ with genotype B,89.2％ with genotype C and 2.0％ with B,C mixed genotype) and YMDD mutant type(6.3％ with genotype B,93.0％ with genotype C and 0.7％ with B,C mixed genotype).The ratio of BCP mutations in YMDD mutant type and YMDD wild type were 76.9％ and 69.6％ respectively and there were no statistical differences between them.In YMDD wild strains,BCP mutations occurred more frequently in genotype C than in genotype B ( P ＜ 0.01 ).While,in YMDD mutant type,there was no significant difference.The ratio of BCP mutations were 83.0％ and 64.6％ between YIDD and YVDD mutants,respectively,there were statistical differences between them (P ＜ 0.05).Conclusion There was a significant difference of the HBV BCP mutation with YMDD wild strains between the genotypes B and C.Mutation rate of the HBV BCP with YMDD mutants showed no significant difference between genotypes B and C.There was a significant difference of the HBV BCP mutation with YMDD mutants between the YIDD mutation type and YVDD mutation type. Key words: Hepatitis B virus; Lamivudine-resistant strain; YMDD mutation; Genotype; BCP mutation