Natural YMDD motif mutations in treatment naïve patients with chronic hepatitis B in Huzhou of eastern China.

amivudine (LAM), a nucleoside analog, was the first anti-HBV rug approved for antiviral therapy in China. Long-term antivial therapy with LAM may lead to drug resistance, which is ssociated with a mutation in tyrosine-methionine-aspartic cid-aspartic acid (YMDD) motif of the reverse transcripase in HBV-DNA genome. Several previous studies showed hat YMDD mutations were also present in treatment-naive hronic hepatitis B (CHB) patients, but the prevalence rates of atural YMDD motif mutations in some reports were quite ifferent (from 0% to 26.9%).1–4 However, the relationship etween natural YMDD motif mutations and virus-related haracteristics in CHB patients is also not quite clear. The aim f present study was to assess the prevalence rate of natual YMDD motif mutations and to investigate the associations etween natural YMDD mutations and clinical factors among AM-untreated CHB patients in Huzhou city, eastern China. A total of 202 CHB patients who had never received antivial treatment were recruited from department of infectious iseases in Huzhou central hospital for this study. CHB was iagnosed according to the Chinese consensus criteria. This tudy was approved by the Ethics Committee of Huzhou cenral hospital. All patients provided written informed consent. erum HBV DNA levels were quantified using a real-time CR kit. HBV genotypes were analyzed by genotype-specific aqman probes using a real-time fluorescence PCR. YMDD utations were detected using specific primers for real-time CR. Natural YMDD mutations were found in 20 (9.9%) treatment aive CHB patients. Among these patients, YVDD variants ere detected in 13 cases, YIDD variants in 5 cases, and VDD + YIDD variants in 2 cases. In this study, the rate f natural YMDD motif mutation was not consistent with revious studies.1–4 The reason for the discrepancy might e due to different demographic characteristics, geographcal diversion, other characteristics of study groups, and ample sizes, as well as sensitivity of different detection ethods.2–4 The mean age of patients were 37.8 ± 10.8 and 36.7 ± 13.2 ears for patients with and without natural YMDD motif, B/C mixed 3 0, 0.0