title: Clinical evaluation of the COBAS Amplicor HBV monitor test for measuring serum HBV DNA and comparison with the Quantiplex branched DNA signal amplification assay in Taiwan.
abstract: OBJECTIVE
  To evaluate the performance characteristics and clinical usefulness of the COBAS Amplicor HBV monitor (COBAS-AM) test in Taiwan and to examine its correlation with the Quantiplex branched DNA signal amplification (bDNA) assay for measuring serum hepatitis B virus (HBV) DNA concentrations.
  
  
  METHODS
  HBV DNA was measured by the COBAS-AM test in 149 sera from chronic HBV infected patients that had previously been analysed by the bDNA assay.
  
  
  RESULTS
  The COBAS-AM test showed good reproducibility, with acceptable intra-assay and interassay coefficients of variation (1.6% and 0.9%, respectively) and good linearity (r2=0.98). The overall sensitivity of the COBAS-AM test was significantly higher than that of the bDNA assay (95.3% v 83.2%): 69.6% of samples with HBV DNA below the detection limit of the bDNA assay could be measured by the COBAS-AM test. There was a significant correlation between the results of the two assays (r=0.901; p<0.0001). On average, the results derived from the COBAS-AM test were 0.55 log lower than those of the bDNA assay. HBV DNA concentrations were significantly higher among HBV e antigen (HBeAg) positive patients than negative ones, and higher among patients with abnormal alanine aminotransferase (ALT) concentrations than those with normal ALT concentrations (p=0.0003).
  
  
  CONCLUSIONS
  The COBAS-AM assay, more sensitive in HBeAg negative samples than the bDNA assay, can effectively measure HBV DNA concentrations in Taiwanese patients. HBV DNA values measured by the COBAS-AM test and bDNA assay correlate significantly.
authors.affiliation: Hepatobiliary Division, Department of Internal Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan.
authors.forename: C-Y
authors.initials: CY
authors.lastname: Dai
authors.forename: M-L
authors.initials: ML
authors.lastname: Yu
authors.forename: S-C
authors.initials: SC
authors.lastname: Chen
authors.forename: Z-Y
authors.initials: ZY
authors.lastname: Lin
authors.forename: M-Y
authors.initials: MY
authors.lastname: Hsieh
authors.forename: L-Y
authors.initials: LY
authors.lastname: Wang
authors.forename: J-F
authors.initials: JF
authors.lastname: Tsai
authors.forename: W-L
authors.initials: WL
authors.lastname: Chuang
authors.forename: W-Y
authors.initials: WY
authors.lastname: Chang
mesh_terms: D000293:Adolescent; D000328:Adult; D021121:Branched DNA Signal Amplification Assay; D004279:DNA, Viral / Q000097:blood*; D005260:Female; D006513:Hepatitis B e Antigens / Q000097:blood; D006515:Hepatitis B virus / Q000235:genetics* / Q000302:isolation & purification; D019694:Hepatitis B, Chronic / Q000175:diagnosis* / Q000821:virology; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction / Q000379:methods; D015203:Reproducibility of Results; D012189:Retrospective Studies; D019562:Viral Load
chemical_list: D004279:DNA, Viral; D006513:Hepatitis B e Antigens