Analytical Characteristics of Commercial Cardiac Troponin I and T Immunoassays in Serum from Rats, Dogs, and Monkeys with Induced Acute Myocardial Injury

BACKGROUND: Information is needed regarding analytical characteristics of cardiac troponin (cTn) assays used in preclinical studies. METHODS: We measured cTnI and cTnT in serum from normal animals and animals with induced myocardial injury [Sprague-Dawley (SD) and Wistar rats, beagle dogs, and rhesus (Rh) and cynomolgus (Cy) monkeys]. We evaluated the following assays: for cTnI, Abbott Architect, Bayer Centaur (first and second generation), Beckman Access, DPC Immulite, Dade Dimension, Ortho Vitros ES, Tosoh AIA, and species-specific enzyme immunoassays; for cTnT, Roche Elecsys. RESULTS: We found different species-specific responses for the troponin assays evaluated. Abbott, Bayer Ultra, Beckman, and Dade assays gave good responses across all species. In rats, weak responses were observed with DPC and Ortho, and no measurable response with Tosoh. In dogs, weak responses were observed with Tosoh cTnI, Roche cTnT, and species-specific cTnI. In cynomolgus monkeys, weak responses were observed with species-specific cTnI and Roche cTnT. Assay imprecision was < or = 20% at 3 or more examined cTn concentrations for Beckman (rat, dog, monkey), Dade (rat, dog, monkey), Abbott (rat, dog, monkey), Bayer first generation (dog), Bayer Ultra (rat, dog, monkey), Roche (monkey), DPC (dog, monkey), Ortho (dog, monkey), and Tosoh (dog, monkey) assays, whereas imprecision was < or = 20% at 2 or fewer concentrations for the Bayer first generation (rat, monkey), Roche cTnT (rat, dog), and DPC (rat) assays. CONCLUSIONS: Not all cTn assays are suitable for monitoring cTn in each animal species or strain. Individual assay characterization by animal species is needed to prevent misinterpretation of myocardial injury-based cardiac troponin findings.