title: [Multiple-site analysis of HBV drug-resistant mutations in 340 patients with chronic hepatitis B].
abstract: OBJECTIVE
  To analyze HBV drug-resistant mutations against nucleos(t)ide analogues at 12 reported sites in 340 patients with chronic hepatitis B.
  
  
  METHODS
  Serum HBV DNA was extracted and a nested PCR assay was employed for the reverse transcriptase (RT) gene amplification. Direct sequencing of PCR product was performed. The significance of detected mutations was analyzed in view of clinical data of the patients.
  
  
  RESULTS
  Drug-resistant mutations were detected in 68 patients taking lamivudine (LAM), 10 taking adefovir (ADV), 8 taking entecavir, and 1 taking telbivudine (LdT). M204V and M204I were the most common LAM-resistant mutations. The former usually emerged with L180M while the latter often emerged alone. N236T +/- A181 substitution was the most frequently seen ADV-resistant mutation. ETV-resistant mutations occurred on the basis of LAM-resistant mutations and T184 change was the most common form. LdT-resistance was observed as M204I. Interestingly, these drug-resistant mutations were detected in a few patients who had not been treated with nucleos(t)ide analogues.
  
  
  CONCLUSIONS
  Detection of HBV drug-resistant mutations at multiple sites of the viral RT gene is valuable for discovering and verifying drug resistance and thus is very helpful in planning anti-HBV therapy.
authors.affiliation: Viral Hepatitis Research Laboratory, Institute of Infectious Diseases, 302 Hospital of PLA, Beijing 100039, China.
authors.forename: Dong-ping
authors.initials: DP
authors.lastname: Xu
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
authors.forename: Jun
authors.initials: J
authors.lastname: Cheng
authors.forename: Xiao-dong
authors.initials: XD
authors.lastname: Li
authors.forename: Jiu-zeng
authors.initials: JZ
authors.lastname: Dai
authors.forename: Le
authors.initials: L
authors.lastname: Li
authors.forename: Zhao-ling
authors.initials: ZL
authors.lastname: Liang
authors.forename: Li
authors.initials: L
authors.lastname: Bai
authors.forename: Yan-wei
authors.initials: YW
authors.lastname: Zhong
authors.forename: Zhi-hui
authors.initials: ZH
authors.lastname: Xu
authors.forename: Xiao-qiang
authors.initials: XQ
authors.lastname: Ren
authors.forename: Ling-xia
authors.initials: LX
authors.lastname: Zhang
mesh_terms: D000328:Adult; D004252:DNA Mutational Analysis; D004279:DNA, Viral / Q000235:genetics; D024882:Drug Resistance, Viral / Q000235:genetics*; D005260:Female; D005838:Genotype; D006515:Hepatitis B virus / Q000187:drug effects* / Q000235:genetics*; D019694:Hepatitis B, Chronic / Q000821:virology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D055815:Young Adult
chemical_list: D004279:DNA, Viral