Emergence of the pre C and YMDD mutations and its clinical significance during lamivudine treatment / 中华传染病杂志

ABSTRACT

Objective To explore pre C and YMDD motif mutant of hepatitis B virus during lamivudine therapy. Methods From five chronic hepatitis B patients with serum HBeAg seroconversion but HBV DNA positive by polymerase chain reaction(PCR) following lamivudine therapy, sequences of the pre C and P genes of hepatitis B virus were analyzed by direct PCR product sequencing methods. Results All the five patients were observed to have G to A variations at nucleotide 1896. However, such mutations were observed only in 2 of the 5 patients before HBeAg seroconversion emerged. Meanwhile YMDD mutations were found in all the five patients during lamivudine therapy three of which were M552I mutants, two were M552I associated with L528M. One of the five patients had no reaction to the therapy, four had HBV DNA breakthrough during therapy. Conclusions The mutants of pre C associated with YMDD mutations may arise in the patients with HBeAg seroconversion and positive HBV DNA during the treatment of lamivudine. HBV DNA should be detected in the patients with HBeAg seroconversion to exclude the pre C mutation.