title: Correlation of the occurrence of YMDD mutations with HBV genotypes, HBV-DNA levels, and HBeAg status in Chinese patients with chronic hepatitis B during lamivudine treatment.
abstract: BACKGROUND
  Continuous lamivudine therapy is associated with high rates of YMDD mutations, which are the main causes of drug resistance. The current study explores the association of the emergence of YMDD mutations with pretherapy HBV genotype, HBV-DNA levels, HBeAg status, and serum alanine aminotransferase (ALT) levels in Chinese patients receiving lamivudine therapy for chronic hepatitis B.
  
  
  METHODS
  A total of 319 chronic hepatitis B patients who received lamivudine therapy for more than a year were enrolled in this study. YMDD mutations, HBV genotype, HBV-DNA levels, HBeAg status, and ALT levels were determined prior to their lamivudine treatment and every three months for a year of this therapy.
  
  
  RESULTS
  Among the 319 patients, 137 (42.95%) were infected with genotype B and 182 (57.05%) with genotype C. Up to 94 patients (29.47%) developed YMDD mutations within one year of lamivudine therapy. Furthermore, 50 patients with HBV genotype B and 44 patients with genotype C developed YMDD mutations (36.50% vs 24.18%, P<0.05). Logistic regression analysis showed that pretherapy HBV genotype, HBV-DNA levels, and HBeAg status are independent factors for the emergence of YMDD mutations (HBV genotype: OR=2.159, 95% CI 1.291-3.609, P=0.003; HBV-DNA: OR=1.653, 95% CI 1.231-2.218, P=0.001; HBeAg: OR=2.021, 95% CI 1.201-3.399, P=0.008).
  
  
  CONCLUSIONS
  HBV genotype, HBV-DNA levels, and HBeAg status at baseline are the independent factors associated with the emergence of YMDD mutations among Chinese patients receiving lamivudine therapy for chronic hepatitis B. These findings are helpful to the development of therapeutic strategies for these patients.
authors.affiliation: Department of Chinese Pharmacy, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Wu
authors.forename: Min-Jin
authors.initials: MJ
authors.lastname: Wu
authors.forename: Xiao-Lin
authors.initials: XL
authors.lastname: Zhuge
authors.forename: Shao-Ming
authors.initials: SM
authors.lastname: Zhu
authors.forename: Biao
authors.initials: B
authors.lastname: Zhu
mesh_terms: D000328:Adult; D000368:Aged; D000410:Alanine Transaminase / Q000097:blood; D000596:Amino Acids / Q000235:genetics*; D000998:Antiviral Agents / Q000627:therapeutic use; D001224:Aspartic Acid / Q000235:genetics; D002681:China; D004279:DNA, Viral / Q000097:blood* / Q000235:genetics*; D024882:Drug Resistance, Viral / Q000235:genetics; D005260:Female; D005838:Genotype; D006513:Hepatitis B e Antigens / Q000097:blood*; D006515:Hepatitis B virus / Q000235:genetics*; D019694:Hepatitis B, Chronic / Q000097:blood / Q000188:drug therapy* / Q000235:genetics; D006801:Humans; D007532:Isoleucine / Q000235:genetics; D019259:Lamivudine / Q000627:therapeutic use*; D016015:Logistic Models; D008297:Male; D008715:Methionine / Q000235:genetics; D008875:Middle Aged; D009154:Mutation / Q000235:genetics*; D012189:Retrospective Studies; D014443:Tyrosine / Q000235:genetics; D014633:Valine / Q000235:genetics
chemical_list: D000596:Amino Acids; D000998:Antiviral Agents; D004279:DNA, Viral; D006513:Hepatitis B e Antigens; D007532:Isoleucine; D019259:Lamivudine; D001224:Aspartic Acid; D014443:Tyrosine; D008715:Methionine; D000410:Alanine Transaminase; D014633:Valine