title: [Effect of initial virologic response to adefovir on the development of resistance to adefovir in lamivudine-resistant chronic hepatitis B].
abstract: OBJECTIVE
  Adefovir dipivoxil (ADV) resistance in patients with lamivudine-resistant chronic hepatitis B is not well understood. This study examined the initial virologic response (IVR) to ADV, the rate of ADV resistance and the factors associated with ADV resistance.
  
  
  METHODS
  Eighty one lamivudine-resistant HBeAg-positive patients were enrolled in this study. IVR was defined as HBV DNA < 4 log10 copies/mL after 6 months of therapy.
  
  
  RESULTS
  IVR was observed in 37/81(45.7%) patients and it was associated with higher pretreatment ALT (P=0.002), and low pretreatment HBV DNA level (P=0.015). The HBV DNA levels were significantly higher in the non-IVR patients than the IVR patients at 12, 18 and 24 months (4.73 vs 2.59, 4.53 vs 2.31, 4.39 vs 2.40 log10 copies/mL, respectively; P<0.01). During the follow-up period, 17(21.0%) patients showed phenotypic resistance to ADV and 9 (11.1%) patients had ADV-resistant mutations. The cumulative probabilities of the phenotypic resistance to ADV at 12 and 24 months were 8.7% and 32.5%, respectively. The cumulative probabilities of the genotypic resistance to ADV at 12 and 24 months were 0% and 14.6%, respectively. Resistance to ADV was associated with a higher pretreatment HBV DNA (P=0.019), and non-IVR (P<0.001).
  
  
  CONCLUSIONS
  The cumulative probabilities of the phenotypic and genotypic resistance to ADV at 24 months were 32.5% and 14.6%. The high pretreatment HBV DNA and non-IVR (HBV DNA >/= 4 log10 copies/mL after 6 months of therapy) were associated with ADV resistance.
authors: Department of Internal Medicine, Chonbuk National University Medical School, Jeonju, Korea.
authors: In Hee
authors: IH
authors: Kim
authors: Seong Hun
authors: SH
authors: Kim
authors: Hyun Chul
authors: HC
authors: Kim
authors: Kyoung Deok
authors: KD
authors: Shin
authors: Sang Wook
authors: SW
authors: Kim
authors: Seung Ok
authors: SO
authors: Lee
authors: Soo Teik
authors: ST
authors: Lee
authors: Dae Ghon
authors: DG
authors: Kim
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D000328:Adult; D000410:Alanine Transaminase / Q000097:blood; D000998:Antiviral Agents / Q000627:therapeutic use*; D004279:DNA, Viral / Q000097:blood; D024882:Drug Resistance, Viral; D005260:Female; D006513:Hepatitis B e Antigens / Q000097:blood; D006515:Hepatitis B virus / Q000187:drug effects / Q000235:genetics; D019694:Hepatitis B, Chronic / Q000188:drug therapy* / Q000821:virology; D006801:Humans; D019259:Lamivudine / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D063065:Organophosphonates / Q000627:therapeutic use*; D011237:Predictive Value of Tests; D012189:Retrospective Studies
chemical_list: D000998:Antiviral Agents; D004279:DNA, Viral; D006513:Hepatitis B e Antigens; D063065:Organophosphonates; D019259:Lamivudine; C053001:adefovir; D000410:Alanine Transaminase; D000225:Adenine