title: Analytic validation and comparison of three commercial immunoassays for measurement of plasma atrial/A-type natriuretic peptide concentration in horses.
abstract: Measurement of atrial/A-type natriuretic peptide (ANP) concentrations may be of use for assessment of cardiac disease, and reliable data on the analytic performance of available assays are needed. To assess the suitability for clinical use of commercially available ANP assays, intra-assay and inter-assay coefficient of variation and dilution parallelism were calculated for three immunoassays (RIAPen, RIAPhoen, and an ELISAPen) using blood samples from healthy and diseased horses to cover a wide range of ANP concentrations. Further, agreement between assays was assessed using linear regression and Bland-Altman analyses. For all assays, precision was moderate but acceptable and dilution parallelism was good. All assays showed analytic performance similar to other immunoassays used in veterinary medicine. However, the results from the three assays were poorly comparable. Our study highlights the need for an optimised species-specific assay for equine samples.
authors.affiliation: Equine Department, Vetsuisse Faculty, University of Zurich, 8057 Zurich, Switzerland; Graduate School for Cellular and Biomedical Sciences, University of Bern, 3012 Bern, Switzerland. Electronic address: dtrachsel@vetclinics.uzh.ch.
authors.forename: D S
authors.initials: DS
authors.lastname: Trachsel
authors.affiliation: Equine Department, Vetsuisse Faculty, University of Zurich, 8057 Zurich, Switzerland.
authors.forename: C C
authors.initials: CC
authors.lastname: Schwarzwald
authors.affiliation: Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zurich, 8057 Zurich, Switzerland.
authors.forename: B
authors.initials: B
authors.lastname: Grenacher
authors.affiliation: Equine Department, Vetsuisse Faculty, University of Zurich, 8057 Zurich, Switzerland.
authors.forename: M A
authors.initials: MA
authors.lastname: Weishaupt
mesh_terms: D000818:Animals; D009320:Atrial Natriuretic Factor / Q000097:blood*; D015415:Biomarkers / Q000097:blood*; D006331:Heart Diseases / Q000097:blood / Q000662:veterinary*; D006734:Horse Diseases / Q000097:blood*; D006736:Horses; D007118:Immunoassay / Q000379:methods / Q000592:standards / Q000662:veterinary*; D016014:Linear Models; D015203:Reproducibility of Results
chemical_list: D015415:Biomarkers; D009320:Atrial Natriuretic Factor
keywords: AB; AG; ANP; Accuracy; BNP; Biomarker; CV; Cardiac; ELISA; Equine; N-terminal pro brain/B-type natriuretic peptide; NT-proBNP; Precision; RIA; Radioimmunoassay; antibody; antigen; atrial/A-type natriuretic peptide; brain/B-type natriuretic peptide; coefficient of variation; enzyme-linked immunosorbent assay