Initial evaluation of the Meritas Troponin I test for measurement of equine cardiac troponin I
Cardiac troponin I (cTnI) is considered a specific and a sensitive biomarker of cardiac disease, and due to a high inter-species sequence homology; human cTnI assays can often be used in veterinary medicine. The main aim of this study was to perform an initial evaluation of a human cTnI test, the Meritas Troponin I test, for measurement of equine plasma cTnI, in order to investigate whether the test could be a possible subject for a more comprehensive validation. The hypothesis was that the test could measure equine cTnI, as there is a good homology between equine cTnI and human cTnI.
The evaluation included a dilution parallelism, an intra-assay precision study and measurement of plasma cTnI healthy horses. In the dilution parallelism and the intra-assay precision study, equine plasma with previously established high cTnI concentration, according to another cTnI assay, was used. In addition, cTnI concentration was measured in plasma, collected from 19 horses, without signs of disease at physical and ECG examinations.
The obtained curve in the dilution parallelism was linear, indicating that the Meritas Troponin I test can be used to measure different concentrations of equine cTnI in plasma. The mean CV% of the test was 6.7% when the concentration of cTnI in plasma was above the detection limit of 12 ng/L. However, the CV% varied extensively when the concentration of cTnI in plasma was < 12 ng/L. All healthy horses, except for one, had a mean cTnI concentration below or close to the detection limit of the test, which is consistent with previous studies. The results indicate that the Meritas Troponin I test may be used to measure equine cTnI, and may have a potential use in equine medicine. However, in order to determine its clinical value in horses, a more comprehensive validation is required.