title: Molecular epidemical characteristics of Lamivudine resistance mutations of HBV in southern China.
abstract: BACKGROUND
  Lamivudine (LMV), as the preferred oral drug for use in treatment of HBV, always results in development of resistance mutations after long-term treatment. In this study we investigated chronic hepatitis B (CHB) patients in southern China to determine whether different HBV genotypes affect the incidence of LMV resistance mutations.
  
  
  METHODS
  The study recruited 185 CHB patients living in southern China. Enzyme-linked immunosorbent assay was used to test for HBV serological markers, and HBV DNA was quantified by real-time PCR. Sequencing was performed to detect HBV genotypes and mutations.
  
  
  RESULTS
  There were 49.19% (91/185) CHB patients with HBV resistant to LMV. Only 2 genotypes were found: B and C; 62.16% (115/185) of patients were infected with genotype B HBV and 37.84% (70/185) of patients were infected with genotype C HBV. The incidence rate of LMV resistance was not significantly different between genotype B and C (49.57% vs. 48.57%, P>0.05). For the mean age and sex ratio, no significant difference was found. The pattern of rtM204I alone was predominantly observed (36.26%, 33/91), followed by rtM204V+rtL180M (23.08%, 21/91). The overall incidence rate of rtM204I mutation in genotype B (45.61%, 26/57) was more frequent than that in genotype C (20.59%, 7/34) (45.61% vs. 20.59%, P<0.05), but the incidence rate of other mutation patterns was not significantly different between genotypes B and C.
  
  
  CONCLUSIONS
  Our results emphasize that a LMV resistance test before treatment is of great importance in rational and optimal CHB therapy.
authors.affiliation: Department of Laboratory Medicine, West China Hospital, Sichuan University, Sichuan Province, China.
authors.forename: Si-Yue
authors.initials: SY
authors.lastname: Li
authors.forename: Li
authors.initials: L
authors.lastname: Qin
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.forename: Xing-Bo
authors.initials: XB
authors.lastname: Song
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhou
authors.forename: Juan
authors.initials: J
authors.lastname: Zhou
authors.forename: Xiao-Jun
authors.initials: XJ
authors.lastname: Lu
authors.forename: Ju
authors.initials: J
authors.lastname: Cao
authors.forename: Lan-Lan
authors.initials: LL
authors.lastname: Wang
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.forename: Bin-Wu
authors.initials: BW
authors.lastname: Ying
mesh_terms: D000998:Antiviral Agents / Q000627:therapeutic use*; D002681:China; D024882:Drug Resistance, Viral / Q000235:genetics*; D004797:Enzyme-Linked Immunosorbent Assay; D005838:Genotype; D006509:Hepatitis B / Q000188:drug therapy*; D006515:Hepatitis B virus / Q000235:genetics*; D006801:Humans; D019259:Lamivudine / Q000627:therapeutic use*; D016015:Logistic Models; D009154:Mutation / Q000235:genetics*; D016017:Odds Ratio; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D000998:Antiviral Agents; D019259:Lamivudine