title: [Predictors of lamivudine resistance in patients with chronic hepatitis B virus infection].
abstract: OBJECTIVE
  Drug resistance is a major concern during nucleoside/ nucleotide analogues therapy in patients with chronic hepatitis B virus (HBV) infections. The aim of this study was to measure the risk of lamivudine resistance provided for each predictive factor in patients with chronic HBV infections.
  
  
  METHODS
  A total of 183 patients were analyzed among 315 patients with chronic HBV infections enrolled in a tertiary referral hospital between January 2001 and December 2003 on this retrospective cohort study. AST/ALT, HBeAg/anti-HBe, serum HBV DNA levels were tested for every 3 or 6 months. HBV DNA level was tested using Cobas Amplicor HBV Monitor test. Viral breakthrough was defined as HBV DNA > or = 5 log10 copies/mL on two consecutive visits in patients who, on treatment, achieved HBV DNA < 5 log10 copies/mL. The risk of viral breakthrough was measured using Cox proportional hazards model for variables: age, sex, BMI (kg/m(2)), baseline ALT, HBeAg positivity, baseline HBV DNA level, serum HBV DNA level at 6 month of lamivudine therapy.
  
  
  RESULTS
  The cumulative rates of viral breakthrough were 9.6%, 39.0%, 55.8% at 12, 24, 36 months, respectively. Serum HBV DNA level of 6 month of lamivudine therapy and presence of HBeAg were independent predictors for viral breakthrough. The relative risk was 1.43 (95% C.I. 1.09-1.89, P=0.010) for serum HBV DNA level at 6 months of lamivudine therapy and 1.77 (95% C.I. 1.06-2.95, P=0.029) for presence of HBeAg.
  
  
  CONCLUSIONS
  Serum HBV DNA level at 6 months of therapy and HBeAg positivity were predictors of early lamivudine resistance in patients with chronic HBV infections. An alternate therapy should be considered when serum viral load is high at 6 months of lamivudine therapy.
authors.affiliation: Department of Internal Medicine, Pusan National University School of Medicine, Busan, Korea.
authors.forename: Jeong
authors.initials: J
authors.lastname: Heo
authors.forename: Mong
authors.initials: M
authors.lastname: Cho
authors.forename: Byung Mann
authors.initials: BM
authors.lastname: Cho
authors.forename: Sun Mi
authors.initials: SM
authors.lastname: Lee
authors.forename: Tae Oh
authors.initials: TO
authors.lastname: Kim
authors.forename: Gwang Ha
authors.initials: GH
authors.lastname: Kim
authors.forename: Dae Hwan
authors.initials: DH
authors.lastname: Kang
authors.forename: Geun Am
authors.initials: GA
authors.lastname: Song
mesh_terms: D000328:Adult; D000368:Aged; D000998:Antiviral Agents / Q000627:therapeutic use*; D015415:Biomarkers / Q000032:analysis; D015331:Cohort Studies; D024882:Drug Resistance, Viral; D005260:Female; D006513:Hepatitis B e Antigens / Q000032:analysis*; D006515:Hepatitis B virus / Q000302:isolation & purification; D019694:Hepatitis B, Chronic / Q000188:drug therapy*; D006801:Humans; D019259:Lamivudine / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies
chemical_list: D000998:Antiviral Agents; D015415:Biomarkers; D006513:Hepatitis B e Antigens; D019259:Lamivudine