title: Comparison of ligase detection reaction and real-time PCR for detection of low abundant YMDD mutants in patients with chronic hepatitis B.
abstract: OBJECTIVE
  To compare the ligase detection reaction (LDR) and real-time PCR for detection of low abundant YMDD mutants in patients with chronic hepatitis B infection.
  
  
  METHODS
  Mixtures of plasmids and serum samples from 52 chronic hepatitis B patients with low abundant lamivudine-resistant mutations were tested with LDR and real-time PCR. Time required and reagent cost for both assays were evaluated.
  
  
  RESULTS
  Real-time PCR detected 100, 50, 10, 1 and 0.1% of YIDD plasmid, whereas LDR detected 100, 50, 10, 1, 0.1, and 0.01% of YIDD plasmid, in mixtures with YMDD plasmid of 10(6) copies/mL. Among the 52 clinical serum samples, completely concordant results were obtained for all samples by both assays, and 39 YIDD, 9 YVDD, and 4 YIDD/YVDD were detected. Cost and time required for LDR and real-time PCR are 60/80 CNY (8/10.7 US dollars) and 4.5/2.5 h, respectively.
  
  
  CONCLUSIONS
  LDR and real-time PCR are both sensitive and inexpensive methods for monitoring low abundant YMDD mutants during lamivudine therapy in patients with chronic hepatitis B. LDR is more sensitive and less expensive, while real-time PCR is more rapid.
authors.affiliation: Laboratory Center, Subei People's Hospital, 98 West Nantong Road, Yangzhou 225001, Jiangsu Province, China. wxlf26@163.com
authors.forename: Xiao-Ling
authors.initials: XL
authors.lastname: Wang
authors.forename: Song-Gang
authors.initials: SG
authors.lastname: Xie
authors.forename: Ling
authors.initials: L
authors.lastname: Zhang
authors.forename: Wei-Xia
authors.initials: WX
authors.lastname: Yang
authors.forename: Xing
authors.initials: X
authors.lastname: Wang
authors.forename: Hong-Zhi
authors.initials: HZ
authors.lastname: Jin
mesh_terms: D024882:Drug Resistance, Viral / Q000235:genetics; D005820:Genetic Testing / Q000379:methods*; 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; D022521:Ligase Chain Reaction; D018894:Reverse Transcriptase Inhibitors / Q000627:therapeutic use; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity
chemical_list: D018894:Reverse Transcriptase Inhibitors; D019259:Lamivudine