Probing rate of YMDD motif mutant in lamivudine treatment of Iranian patients with chronic hepatitis B virus infection

BACKGROUND: Lamivudine is an analog nucleoside used for the treatment of chronic hepatitis B virus (CHV) infection. Studies showed that prolonged therapy could induce lamivudine resistance hepatitis B virus (HBV) variants (YMDD motif). In this study, the rate of YMDD motif mutants is determined in lamivudine-treated CHV patients in Iran. MATERIALS AND METHODS: Thirty-three serum specimens of patients with chronic hepatitis who had been treated with lamivudine were included in the study. Serum samples of patients were tested by PCR flash and RFLP as well as tested for HBeAg, HBsAg, and liver enzymes (ALT and AST). RESULTS: Out of the 33 patients enrolled in this study, 82% were male and 18% female, respectively. Mean ALT levels were between 20 and 100 IU/1. HBeAg was positive in 76% of the patients whereas HBs was positive only in 61% of the patients. Furthermore, in 28 patients liver biopsy grade was between 2 and 17 having the stage of 1–6. Moreover, HBsAg negative and HBeAg positive were observed in 30% of the patients. CONCLUSION: During therapy, it was found that patients with lamivudine incidence YMDD mutation were approximately 14%. The ALT levels were also reduced in these patients. This study revealed that there was a significant difference between HBeAg, grade, and YMDD mutation whereas no significant different was observed between HBsAg and HBV DNA PCR. Conclusively, it was found that a significant difference exists between YMDD mutation and lamivudine therapy (17% of patients were HBsAg negative and PCR positive).