title: Partial virological response to adefovir add-on lamivudine rescue therapy in patients with lamivudine-resistant chronic hepatitis B.
abstract: OBJECTIVE
  In patients with lamivudine (LAM)-resistant chronic hepatitis B (CHB) receiving adefovir (ADV) add-on LAM therapy, insufficient viral suppression or the appearance of additional ADV resistance has remained unresolved. This study determined the partial virological response (PVR) criteria to predict a virological response (VR) at week 96 in these patients.
  
  
  METHODS
  96 patients with LAM-resistant CHB (ADV add-on LAM therapy >2 years) were analyzed. For predicting VR at week 96, the area under the receiver operating characteristic curve values at different time points were compared to establish the optimal time point, and the maximal Youden index was calculated to determine the optimal cut-off hepatitis B virus (HBV) DNA level.
  
  
  RESULTS
  50 (52.1%) patients achieved VR at 2 years after ADV add-on LAM therapy. The optimal PVR criteria were determined to be HBV DNA 500 IU/ml at week 48. 44 (45.8%) patients who met optimal PVR criteria showed a significantly higher risk for detectable HBV DNA levels at week 96 than those with a favorable VR (HBV DNA <500 IU/ml) at week 48.
  
  
  CONCLUSIONS
  This study suggested optimal PVR criteria in patients with LAM-resistant CHB receiving ADV add-on LAM therapy. Modification of the antiviral agent regimen should be considered if the serum HBV DNA level exceeds 500 IU/ml at week 48.
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Young Eun
authors.initials: YE
authors.lastname: Chon
authors.forename: Jun Yong
authors.initials: JY
authors.lastname: Park
authors.forename: Sang Hoon
authors.initials: SH
authors.lastname: Ahn
authors.forename: Do Young
authors.initials: DY
authors.lastname: Kim
authors.forename: Kwang-Hyub
authors.initials: KH
authors.lastname: Han
authors.forename: Chae Yoon
authors.initials: CY
authors.lastname: Chon
authors.forename: Ara
authors.initials: A
authors.lastname: Choi
authors.forename: Seung Up
authors.initials: SU
authors.lastname: Kim
mesh_terms: D000225:Adenine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D000328:Adult; D019540:Area Under Curve; D004279:DNA, Viral / Q000097:blood*; D024882:Drug Resistance, Viral; D004359:Drug Therapy, Combination; D005260:Female; D019694:Hepatitis B, Chronic / Q000097:blood / Q000188:drug therapy* / Q000821:virology; D006801:Humans; D019259:Lamivudine / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D063065:Organophosphonates / Q000008:administration & dosage*; D012372:ROC Curve; D018894:Reverse Transcriptase Inhibitors / Q000008:administration & dosage*; D016896:Treatment Outcome
chemical_list: D004279:DNA, Viral; D063065:Organophosphonates; D018894:Reverse Transcriptase Inhibitors; D019259:Lamivudine; C053001:adefovir; D000225:Adenine