Precision performance at low levels and 99th percentile concentration of the Access AccuTnl assay on two different platforms

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 μg/L. 10% CV values (95% confidence interval, Cl) 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% Cl) 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.