Method comparison of cardiac marker assays on PATHFAST, StratusCS, AxSYM, Immulite 2000, triage, elecsys and cardiac...

The purpose of this evaluation was to perform a method comparison of the assays for cardiac troponin I (cTnl), CK-MB, myoglobin, and NT-proBNP on the automated PATHFAST Immuno-Assay Analyzer with respective immunoassays on other commercially available immunoanalyzers. The PATHFAST assays are immunochemiluminescent assays (in single reagent cartridges) employing two mono- or polyclonal antibodies in a sandwich test format. The calibration materials for cTnI and CK-MB are standardized to the reference materials NIST SRM 2921 (troponin CIT complex) and IRMM-IFCC 455 (CK-MB mass). The PATHFAST assays for cTnI, CK-MB, myoglobin, and NT-proBNP on the PATHFAST Analyzer were compared using 118 (NT-proBNP: 90) plasma samples from patients with different cardiovascular diseases with those on the Dade Behring StratusCS Analyzer, on the Abbott AxSYM System, on the DPC IMMMULITE 2000 Analyzer, on the Biosite Triage Meter Plus System, on the Roche Elecsys Immuno Analyzer 2010 and Roche Cardiac Reader System, respectively. The correlation coefficients for the comparison of cTnI methods ranged from 0.953 to 0.982, those for the comparison of myoglobin methods ranged from 0.776 to 0.992, and those for the comparison of CK-MB methods ranged from 0.835 to 0.999, with the Triage System giving in all comparisons the lowest correlation. Also the comparison of PATHFAST NTproBNP against the Roche Elecsys assay yielded a very good correlation (r = 0.992). The slopes of the regression line among methods showed considerable variation indicating that standardization efforts by international groups are indispensable to achieve harmonization of results. In summary, this evaluation study confirms the overall good correlation of the results obtained with assays for cardiac markers developed on the PATHFAST analyzer with those on other immunoassay platforms and thus the analytical reliability of the developed methods.