title: Abbott RealTime HBV assay is more sensitive in detection of low viral load and little impacted by drug resistant mutation in chronic hepatitis B patients under nucleot(s)ide analogues therapy.
abstract: BACKGROUND
  Selection of drug-resistant strains may lead to failure of HBV antiviral therapy. There is little information whether there is detection difference in drug resistant mutations between different viral load assays of HBV.
  
  
  OBJECTIVE
  This study is aimed to investigate whether there is drug-resistant strains related detection difference between Abbott RealTime HBV (RealTime) and CobasAmpliPrep/CobasTaqMan HBV assays 2.0 (TaqMan).
  
  
  METHODS
  One hundred and thirty-four CHB patients who received HBV anti-viral therapy were enrolled. HBV virological markers were tested 3 months apart regularly. Serum HBV DNA levels were determined using the TaqMan and RealTime. YMDD (rt180M and rt204V) mutation was checked in patients who experienced virologic breakthrough (VBT).
  
  
  RESULTS
  The correlation of HBV DNA observed between the RealTime and TaqMan was good for all 571 samples (R2 = 0.797; P<0.001). However, the correlation in the 434 samples with HBV DNA level <3 log10 IU/ml was not as good as in all samples (R2 = 0.457). Overall, 21.5% of samples had a detection difference of ≥ 1 log10 IU/ml with 91.9% of these having HBV DNA level <3 log10 IU/ml. Twenty-four patients experienced VBT. Three of these patients had acquired the YMDD mutation and exhibited discordant viral load results between the two methods tested. In each case, persistent HBV DNA was detected by RealTime and undetectable with TaqMan. Of the patients who experienced a VBT and had acquired YMDD mutation, 4.7% had undetectable HBV DNA by TaqMan while all were detectable with RealTime.
  
  
  CONCLUSIONS
  RealTime assay is more sensitive and is little impacted by the development of drug resistant mutation.
authors.affiliation: Division of Hepatobiliary, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Hepatitis Center, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Ming-Lun
authors.initials: ML
authors.lastname: Yeh
authors.affiliation: Division of Hepatobiliary, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; Faculty of Internal Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Occupational Medicine, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Chung-Feng
authors.initials: CF
authors.lastname: Huang
authors.affiliation: Department of Internal Medicine, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Ching-I
authors.initials: CI
authors.lastname: Huang
authors.affiliation: Division of Hepatobiliary, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.
authors.forename: Shu-Fen
authors.initials: SF
authors.lastname: Liu
authors.affiliation: Division of Hepatobiliary, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; Hepatitis Center, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Hua-Ling
authors.initials: HL
authors.lastname: Yang
authors.affiliation: Department of Internal Medicine, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Ming-Yen
authors.initials: MY
authors.lastname: Hsieh
authors.affiliation: Division of Hepatobiliary, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; Faculty of Internal Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Internal Medicine, Kaohsiung Municipal Hsiao-Kang Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Jee-Fu
authors.initials: JF
authors.lastname: Huang
authors.affiliation: Division of Hepatobiliary, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Faculty of Internal Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Hepatitis Center, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Chia-Yen
authors.initials: CY
authors.lastname: Dai
authors.affiliation: Division of Hepatobiliary, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; Faculty of Internal Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Hepatitis Center, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Wan-Long
authors.initials: WL
authors.lastname: Chuang
authors.affiliation: Division of Hepatobiliary, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; Faculty of Internal Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Hepatitis Center, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Ming-Lung
authors.initials: ML
authors.lastname: Yu
mesh_terms: D000328:Adult; D000998:Antiviral Agents / Q000737:chemistry / Q000494:pharmacology* / Q000627:therapeutic use; D004279:DNA, Viral / Q000032:analysis / Q000235:genetics; D024882:Drug Resistance, Viral / Q000235:genetics*; D005260:Female; D006515:Hepatitis B virus / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D019694:Hepatitis B, Chronic / Q000188:drug therapy / Q000821:virology*; D006801:Humans; D057230:Limit of Detection; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009705:Nucleosides / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use; D009711:Nucleotides / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D019914:Taq Polymerase / Q000378:metabolism; D019562:Viral Load / Q000187:drug effects / Q000235:genetics
chemical_list: D000998:Antiviral Agents; D004279:DNA, Viral; D009705:Nucleosides; D009711:Nucleotides; D019914:Taq Polymerase