title: Precision performance at low levels and 99th percentile concentration of the Access AccuTnl assay on two different platforms.
abstract: BACKGROUND
  Cardiac troponins currently represent the preferred biomarkers for the detection of myocardial necrosis. The objective of the present study was to compare the performance of the Access AccuTnl assay (Beckman Coulter) measured on two different platforms, the UniCel Dxl 800 and the Access 2 (Beckman Coulter). In particular, the serum cardiac troponin I (cTnl) concentration corresponding to 10% coefficient of variation (CV), the cTnl assay minimum detectable concentration (MDC), and the serum cTnl 99th percentile in healthy subjects were calculated.
  
  
  METHODS
  The Access AccuTnl is a paramagnetic particle chemiluminescent immunoassay. Imprecision profiles were determined according to the Clinical and Laboratory Standards Institute EP5-A protocol using serum pools. The MDC was calculated as mean +3 SD of 20 determinations of the zero calibrator during one run. The 99th percentile was determined analyzing serum samples from 679 healthy blood donors (523 males, 156 females; 18-71 years old).
  
  
  RESULTS
  cTnl concentrations are given in microg/L. 10% CV values (95% confidence interval, CI) were 0.0577 (0.0467-0.0750) (UniCel Dxl 800) and 0.0486 (0.0255-0.0596) (Access 2). MDC values were 0.011 (UniCel Dxl 800) and 0.012 (Access 2). The 99th percentile (95% CI) value was 0.0340 (0.0298-0.0410).
  
  
  CONCLUSIONS
  Our data confirm the reliability of the evaluated cTnl assay and demonstrate the comparability of the cTnl values between the platforms studied.
authors.affiliation: Department of Laboratory Medicine, University Hospital, Padova, Italy. martina.zaninotto@sanita.padova.it
authors.forename: Martina
authors.initials: M
authors.lastname: Zaninotto
authors.forename: Monica Maria
authors.initials: MM
authors.lastname: Mion
authors.forename: Enrica
authors.initials: E
authors.lastname: Novello
authors.forename: Marco
authors.initials: M
authors.lastname: Moretti
authors.forename: Ernesto
authors.initials: E
authors.lastname: Delprete
authors.forename: Marco Bruno
authors.initials: MB
authors.lastname: Rocchi
authors.forename: Davide
authors.initials: D
authors.lastname: Sisti
authors.forename: Mario
authors.initials: M
authors.lastname: Plebani
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D008163:Luminescent Measurements / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood* / Q000175:diagnosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014336:Troponin / Q000097:blood*
chemical_list: D015415:Biomarkers; D014336:Troponin