title: Establishment of a new quantitative detection approach to adefovir-resistant HBV and its clinical application.
abstract: OBJECTIVE
  To establish the more feasible and sensitive assessment approach to the detection of adefovir (ADV) resistance-associated hepatitis B virus (HBV) quasispecies.
  
  
  METHODS
  Based on the characteristics of rtA181V/T and rtN236T mutations, a new approach based on real-time fluorescent quantitative polymerase chain reaction (RT-PCR) was established for the detection of ADV-resistant HBV quasispecies, total HBV DNA, rtA181 and rtN236 mutations in blood samples from 32 chronic hepatitis B (CHB) patients with unsatisfactory curative effect on ADV and compared with routine HBV DNA sequencing.
  
  
  RESULTS
  Both the sensitivity and specificity of this new detection approach to ADV-resistant HBV quasispecies were 100%, which were much higher than those of direct HBV DNA sequencing. The approach was able to detect 0.1% of mutated strains in a total plasmid population. Among the 32 clinical patients, single rtA181 and rtN236T mutation and double rtA181T and rtN236T mutations were detected in 20 and 8, respectively, while ADV-resistant mutations in 6 (including, rtA181V/T mutation alone in 5 patients) and no associated mutations in 26.
  
  
  CONCLUSIONS
  This new approach is more feasible and efficient to detect ADV-resistant mutants of HBV and ADV-resistant mutations before and during ADV treatment with a specificity of 100% and a sensitivity of 100%.
authors.affiliation: Shanghai Laboratory of Disease and Health Genomics, Chinese National Human Genome Center, Shanghai 201203, China.
authors.forename: Wei-Feng
authors.initials: WF
authors.lastname: Zhao
authors.forename: You-Lin
authors.initials: YL
authors.lastname: Shao
authors.forename: Liang-Yun
authors.initials: LY
authors.lastname: Chen
authors.forename: Jin-Hua
authors.initials: JH
authors.lastname: Wu
authors.forename: Yi-Ling
authors.initials: YL
authors.lastname: Zhu
authors.forename: Jian-He
authors.initials: JH
authors.lastname: Gan
authors.forename: Hui
authors.initials: H
authors.lastname: Xiong
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives*; D000328:Adult; D000998:Antiviral Agents; D004279:DNA, Viral / Q000235:genetics; D024882:Drug Resistance, Viral; D005260:Female; D006515:Hepatitis B virus / Q000235:genetics*; D019694:Hepatitis B, Chronic / Q000188:drug therapy / Q000821:virology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D063065:Organophosphonates; D016133:Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA; D055815:Young Adult
chemical_list: D000998:Antiviral Agents; D004279:DNA, Viral; D063065:Organophosphonates; C053001:adefovir; D000225:Adenine