title: Hepatitis C antibody intraassay correlation: is retest in duplicate necessary?
abstract: BACKGROUND
  The hepatitis C virus antibody (anti-HCV) can be identified with third-generation immunoassays. The purpose of this study was to define the correlation or agreement between first and second reactive results of anti-HCV microparticle-based enzyme immunoassay (MEIA) and of chemiluminescence assays (ChLIAs) in blood donors, to determine whether repeat testing is necessary.
  
  
  METHODS
  Commercially available assays, third-generation HCV MEIA (Abbott), third-generation HCV ChLIA (Ortho), and third-generation HCV ChLIA (Abbott), were used to evaluate anti-HCV repeatedly reactive blood obtained from donations made at 23 Mexican blood centers over a period of 1 year. The intraassay correlation between first and second reactive anti-HCV tests with the Pearson r test and the coefficient of variation (CV) were determined.
  
  
  RESULTS
  The intraassay correlation of 565 anti-HCV repeatedly reactive samples was 0.996 for the Abbott third-generation HCV MEIA, 0.995 for the Ortho third-generation HCV ChLIA, and 0.993 for the Abbott third-generation HCV ChLIA. The CVs of these assay systems were 2.82, 5.33, and 5.69 percent, respectively.
  
  
  CONCLUSIONS
  A highly significant intraassay correlation between anti-HCV duplicates was found. Specimens with a single reactive anti-HCV result with the Abbott third-generation HCV MEIA, Ortho third-generation HCV ChLIA, and Abbott third-generation HCV ChLIA assays should be considered as positive and need not be retested. Such a change in the algorithm for blood donor screening is feasible because of the availability of highly automated platforms.
authors.affiliation: Health Research Council in Jalisco State, Mexican Institute of Social Security, Guadalajara, Jalisco, Mexico. acontreras53@hotmail.com
authors.forename: Ana M
authors.initials: AM
authors.lastname: Contreras
authors.forename: Erendi
authors.initials: E
authors.lastname: Tinoco
authors.forename: Alfredo
authors.initials: A
authors.lastname: Celis
authors.forename: Bárbara
authors.initials: B
authors.lastname: Novelo
authors.forename: M V Patricia
authors.initials: MV
authors.lastname: Romero
authors.forename: Etelvina
authors.initials: E
authors.lastname: Carrada
authors.forename: Ricardo
authors.initials: R
authors.lastname: Jiménez-Méndez
mesh_terms: D016174:Hepacivirus / Q000235:genetics; D018937:Hepatitis C Antibodies / Q000097:blood* / Q000276:immunology*; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D012367:RNA, Viral / Q000235:genetics; D015203:Reproducibility of Results
chemical_list: D018937:Hepatitis C Antibodies; D012367:RNA, Viral