Analytic validation and comparison of three commercial immunoassays for measurement of plasma atrial/A-type natriuretic peptide concentration in horses.

The research article investigates the effectiveness of three immunoassays used to measure the atrial/A-type natriuretic peptide (ANP) concentration in horses, which is useful in assessing cardiac disease. The study found that while these commercially available tests showed adequate precision and dilution parallelism, their results were not easily comparable, implying a need for an optimised species-specific test for horses.

Study Design and Methodology

• The research conducted comparisons on three commercially available immunoassays: RIAPen, RIAPhoen, and ELISAPen. These tests are employed to measure the concentration of atrial/A-type natriuretic peptide (ANP) in the blood of horses.
• The study worked with blood samples from both healthy and diseased horses to cover a broad range of ANP concentrations, ensuring a diverse sample set for more accurate results.
• Methodologies used to assess the agreement between assays included linear regression and Bland-Altman analyses.

Study Findings

• The three tests (RIAPen, RIAPhoen, and ELISAPen) all demonstrated acceptable levels of precision and also showcased good dilution parallelism. This means that these tests performed consistently across multiple trials and produced results proportional to the dilution of the sample.
• However, while the tests performed well individually, the study found that the outcomes from the three tests were not readily comparable. This discrepancy introduces potential difficulties when trying to compare or combine results from different assays.
• The observed performance of these assays was reported to be in line with other immunoassays used in veterinary medicine, meaning these tests are commonly used and their performance is considered standard within the veterinary field.

Conclusions and Recommendations

• Despite their moderate precision and good dilution parallelism, the lack of comparability between the results of the three immunoassays used to measure ANP in horses indicates a possible gap in the current diagnostic resources.
• The research concludes by highlighting the need for an optimized species-specific assay for equine samples to allow better and more accurate comparison of results across different assays.