title: Accuracy of a rapid enzyme-linked immunosorbent assay to measure progesterone in mares.
abstract: The aim of this study was to validate an enzyme-linked immunosorbent assay (ELISA) for the measurement of progesterone (P4) in mares. Specifically, the objectives were as follows: (1) to determine the specificity and sensitivity of the ELISA test for determination of P4, (2) to measure the potential agreement between the 2 people performing the test, and 3) to evaluate the effect of time on the outcome. Ten mares were sampled on the day before ovulation (D-1), and on days 1 (D1), 3 (D3), and 5 (D5) following ovulation, during the reproductive season. While mares were cycling regularly, estrus was induced by the injection of 5 mg of prostaglandin (PGF2) and monitored starting on the 4th day by daily transrectal palpation and ultrasonography to determine the time of ovulation. Blood was collected and all samples (n=96) were assayed for P4 by a semiquantitative ELISA, by chemiluminescent immunoassay, and by radioimmunoassay (RIA). Based on the RIA, values of P4 on D-1, D1, D3, and D5 were significantly different (P < 0.0001) with mean and standard deviation(s) of 0.004, s = 0.52; 2.05, s = 2.58; 8.37, s = 4.17; and 12.76, s = 4.00 ng/mL respectively. The sensitivity and specificity of the semiquantitative assay were 94% and 95%, respectively for the lowest values of P4 (< 1.0 ng/mL). The value of kappa was 0.90 between 2 individuals performing the test. In conclusion, these results suggest that the semiquantitative test may be used reliably and economically to evaluate P4 levels in equine plasma in the clinical
authors.affiliation: Department of Clinical Sciences, University of Montreal, 3200 rue Sicotte, Saint-Hyacinthe.
authors.forename: Fabien
authors.initials: F
authors.lastname: Relave
authors.forename: Réjean C
authors.initials: RC
authors.lastname: Lefebvre
authors.forename: Sandra
authors.initials: S
authors.lastname: Beaudoin
authors.forename: Christopher
authors.initials: C
authors.lastname: Price
mesh_terms: D000818:Animals; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000592:standards / Q000662:veterinary*; D004971:Estrus / Q000097:blood / Q000502:physiology; D005260:Female; D006736:Horses / Q000097:blood*; D007118:Immunoassay / Q000379:methods / Q000592:standards / Q000662:veterinary; D010060:Ovulation / Q000097:blood / Q000502:physiology; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000097:blood / Q000502:physiology; D011374:Progesterone / Q000097:blood*; D011863:Radioimmunoassay / Q000379:methods / Q000592:standards / Q000662:veterinary; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013997:Time Factors