title: Optimal correlation between different instruments for Fibrotest-Actitest protein measurement in patients with chronic hepatitis C.
abstract: OBJECTIVE
  Combination of alpha 2-macroglobulin, haptoglobin, apolipoprotein-A1, gamma-glutamyl transpeptidase, total bilirubin and alanine aminotransferase measurements allows to determine the Fibrotest-Actitest score, an alternative to liver biopsy in hepatitis C virus infection. The aims of this study were to evaluate the analytical variability of the Fibrotest-Actitest proteins alpha 2-macroglobulin, haptoglobin and apolipoprotein-A1, and to assess their impact on the Fibrotest-Actitest scores.
  
  
  METHODS
  We compared 129 sera from hepatitis C virus infected patients for alpha 2-macroglobulin, haptoglobin and apolipoprotein-A1 levels obtained with the Immage (Beckman-Coulter) and the BNProspec (Dade-Berhing) automates. We evaluated Fibrotest-Actitest results obtained with the two nephelemeters.
  
  
  RESULTS
  Optimal correlation was found for alpha 2-macroglobulin (Y=1.05X + 0.01, correlation coefficient: 0.98) and haptoglobin (Y=1.05X - 0.07, correlation coefficient: 0.98). Apolipoprotein-A1 levels, as determined by Immage, were slightly lower than those obtained by BNProspec (Y=0.86X - 0.02, CC=0.95). When Fibrotest-Actitest scores obtained with the two protein measurements were compared adjusting for apolipoprotein-A1 from Immage, the concordance rate was 0.903+/-0.096, with only 2/107 patients showing minimal discordance>0.10 for Fibrotest, and 1.00+/-0.06 for Actitest, with no discordance>0.10.
  
  
  CONCLUSIONS
  Measurement of apolipoprotein-A1, included in the Fibrotest-Actitest score, depends on the equipment used. Such discordance is of little clinical consequence for liver fibrosis evaluation in hepatitis C virus patients.
authors.affiliation: Laboratoire central d'immunologie, CHU de Nice, Hôpital de l'Archet, Nice Université de Nice Sophia-Antipolis, 151 route Saint-Antoine de Ginistière, Nice. allieri@unice.fr
authors.forename: Maria Alessandra
authors.initials: MA
authors.lastname: Rosenthal-Allieri
authors.forename: Albert
authors.initials: A
authors.lastname: Tran
authors.forename: Philippe
authors.initials: P
authors.lastname: Halfon
authors.forename: Françoise
authors.initials: F
authors.lastname: Imbert-Bismut
authors.forename: Mona
authors.initials: M
authors.lastname: Munteanu
authors.forename: Djamila
authors.initials: D
authors.lastname: Messous
authors.forename: Marie-Line
authors.initials: ML
authors.lastname: Peritore
authors.forename: Thierry
authors.initials: T
authors.lastname: Poynard
authors.forename: Alain
authors.initials: A
authors.lastname: Bernard
mesh_terms: D016632:Apolipoprotein A-I / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D006242:Haptoglobins / Q000032:analysis*; D019698:Hepatitis C, Chronic / Q000097:blood*; D006801:Humans; D008111:Liver Function Tests / Q000379:methods*; D009391:Nephelometry and Turbidimetry; D012044:Regression Analysis; D000511:alpha-Macroglobulins / Q000032:analysis*
chemical_list: D016632:Apolipoprotein A-I; D015415:Biomarkers; D006242:Haptoglobins; D000511:alpha-Macroglobulins