title: Performance of an automated system for quantitation of hepatitis C virus core antigen.
abstract: The performance of an automated system for the HCV core antigen assay using the Lumispot LS-2000 automated analyzer was evaluated against that of the COBAS AMPLICOR HCV MONITOR Test, version 2.0 (COBAS HCM-2) for the testing of sera from 155 chronic hepatitis C patients. The within-run coefficient of variations (CVs) and the between-day CVs were <9.6 and <8.4%, respectively. The analytical detection limit of the HCV core antigen assay was 5.0 fmol/l and it was linear up to at least 45000 fmol/l. No blood elements interfered with the assay. HCV core antigen levels were significantly correlated with HCV RNA levels in both serogroup 1 and serogroup 2 (r=0.829, P<0.001). It is estimated that 100 fmol/l of HCV core antigen level was equivalent to approximately 30000 IU/ml of HCV RNA level. Three sera had HCV core antigen levels below the detection limit of the assay and their HCV RNA levels as determined by COBAS HCM-2 assay were very low at 1000, 1100 and 1700 IU/ml, respectively. In six IFN responders among seven patients, HCV core antigen levels were in parallel with HCV RNA levels. In conclusion, since this assay demonstrated good reproducibility, a favorable dynamic range and adequate sensitivity, it may be useful as an alternative direct marker of viral level monitoring in patients with hepatitis C.
authors.affiliation: Department of Laboratory Medicine, Graduate school of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan. saito-lab@h.u-tokyo.ac.jp
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Saito
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Yokota
authors.forename: Emiko
authors.initials: E
authors.lastname: Takahashi
authors.forename: Fumiko
authors.initials: F
authors.lastname: Mashige
authors.forename: Akiko
authors.initials: A
authors.lastname: Yoneyama
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Nakahara
authors.forename: Noboru
authors.initials: N
authors.lastname: Okamura
mesh_terms: D001331:Automation; D021121:Branched DNA Signal Amplification Assay / Q000379:methods*; D005069:Evaluation Studies as Topic; D016174:Hepacivirus / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D019698:Hepatitis C, Chronic / Q000097:blood / Q000188:drug therapy / Q000821:virology; D006801:Humans; D011933:Reagent Kits, Diagnostic; D015203:Reproducibility of Results; D014758:Viral Core Proteins / Q000032:analysis / Q000097:blood*
chemical_list: D011933:Reagent Kits, Diagnostic; D014758:Viral Core Proteins; C069130:nucleocapsid protein, Hepatitis C virus