Rate of YMDD motif mutants in lamivudine-untreated Iranian patients with chronic hepatitis B virus infection.

BACKGROUND Lamivudine is used for the treatment of chronic hepatitis B patients. Recent studies show that the YMDD motif mutants (resistant hepatitis B virus) occur as natural genome variability in lamivudine-untreated chronic hepatitis B patients. In this study we aimed to determine the rate of YMDD motif mutants in lamivudine-untreated chronic hepatitis B patients in Iran. PATIENTS AND METHODS A total of 77 chronic hepatitis B patients who had not been treated with lamivudine were included in the study. Serum samples from patients were tested by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) for detection of YMDD motif mutants. All patients were also tested for liver enzymes, anti-HCV, HBeAg, and anti-HBe. RESULTS Of the 77 patients enrolled in the study, 73% were male and 27% were female. Mean ALT and AST levels were 124.4+/-73.4 and 103.1+/-81 IU/l, respectively. HBeAg was positive in 40% and anti-HBe in 60% of the patients. Anti-HCV was negative in all of them. YMDD motif mutants were not detected in any of the patients despite the liver enzyme levels and the presence of HBeAg or anti-HBe. CONCLUSION Although the natural occurrence of YMDD motif mutants in lamivudine-untreated patients with chronic hepatitis B has been reported, these mutants were not detected in Iranian lamivudine-untreated chronic hepatitis B patients.