Initial analytic quality assessment and method comparison of an immunoassay for adrenocorticotropic hormone measurement in equine samples.
Abstract: Equine pituitary pars intermedia dysfunction (PPID) may be diagnosed by measuring baseline plasma adrenocorticotrophic hormone (ACTH). The Immulite 1000 analyzer uses an automated chemiluminescence enzyme assay, previously validated for measuring equine ACTH. Recently, an automated bench-top immunoassay analyzer (AIA-360), designed for analytes in people, became available for veterinary use. Objective: Objectives were to evaluate analytic performance of the AIA immunoassay for measuring equine ACTH, and compare the results with those obtained by the Immulite. Methods: Adrenocorticotrophic hormone was measured in plasma samples from 52 clinical cases. For the AIA, within- and between-run coefficients of variation (CV) were assessed, linearity and recovery studies performed, and observed total error (TEobs ) calculated. Correlation and agreement between the 2 analyzers were also evaluated. Results: Within-run and between-run CV of the AIA ranged from 2.3% to 4% and 3.5% to 8%, respectively. ACTH recoveries ranged from 89.5% to 115.9%. TEobs at 26.5 pg/mL ACTH was 4.1 pg/mL. The ACTH results (median: 25.9 pg/mL; range: 4.3-276.7 pg/mL) with AIA were significantly lower (P < .0001) than with the Immulite (median: 29.9 pg/mL; range: 10.3-639.0 pg/mL). Correlation between the 2 analyzers was r = 0.882 (P < .0001), with a significant bias for the AIA of -16 pg/mL. The 2 methods were not identical within inherent imprecision. Conclusions: The AIA is precise for measuring ACTH in horses. Although correlation between the instruments is good, the values obtained by the immunoassays cannot be used interchangeably and should be interpreted using reference intervals established for each analyzer to avoid false negatives. Diagnostic sensitivity and specificity of the AIA-360 should be evaluated before clinical use.
© 2016 American Society for Veterinary Clinical Pathology.
Publication Date: 2016-01-12 PubMed ID: 26756538DOI: 10.1111/vcp.12326Google Scholar: Lookup
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- Evaluation Study
- Journal Article
- Research Support
- Non-U.S. Gov't
- Adrenal
- Analytical Methods
- Biochemistry
- Clinical Pathology
- Clinical Study
- Comparative Study
- Correlation Analysis
- Diagnosis
- Diagnostic Technique
- Disease Diagnosis
- Equine Health
- Hormones
- Horses
- Immunoassay
- Laboratory Methods
- Physiology
- Pituitary Pars Intermedia Dysfunction
- Plasma
- Veterinary Medicine
- Veterinary Procedure
- Veterinary Research
Summary
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The research article is about the evaluation of an immunoassay for adrenocorticotrophic hormone (ACTH) measurement in horses, comparing results from a new automated bench-top analyzer (AIA-360) with an existing established analyzer (Immulite 1000).
Introduction and Objectives
- The study primarily focused on evaluating the analytic performance of an automated bench-top immunoassay analyzer (AIA-360) designed for ACTH measurement in horses and comparing results to an existing validated analyzer (Immulite 1000).
- The goal was to determine whether the new assay could accurately diagnose equine pituitary pars intermedia dysfunction (PPID), a condition often identified by measuring baseline plasma ACTH.
Methods
- The researchers used plasma samples from 52 clinical cases to measure ACTH levels.
- For the AIA-360, they assessed within- and between-run coefficients of variation (CV), performed linearity and recovery studies, and calculated observed total error (TEobs).
- They then evaluated the correlation and agreement between the AIA-360 and Immulite results.
Results
- They found that within-run and between-run CV of the AIA-360 ranged from 2.3% to 4% and 3.5% to 8% respectively, suggesting good precision of this method in measuring horse ACTH.
- The ACTH recoveries ranged from 89.5% to 115.9%.
- The TEobs at 26.5 pg/mL ACTH was 4.1 pg/mL.
- When comparing the two assays, the results from the AIA-360 (median: 25.9 pg/mL; range: 4.3-276.7 pg/mL) were significantly lower than the Immulite (median: 29.9 pg/mL; range: 10.3-639.0 pg/mL).
- They noticed a significant bias for the AIA-360 of -16 pg/mL and a correlation between the two analyzers was r = 0.882, indicating a good correlation, though not identical.
Conclusions
- The AIA-360 shows precision, though the results cannot be used interchangeably with the immunoassays from the Immulite due to their difference in measurements.
- To avoid false negatives, the values should be interpreted using reference intervals established for each analyzer.
- Before clinical application, the diagnostic sensitivity and specificity of the AIA-360 should be further evaluated.
Cite This Article
APA
Irvine KL, Burt K, Hill AJ, Shaw S, Papasouliotis K.
(2016).
Initial analytic quality assessment and method comparison of an immunoassay for adrenocorticotropic hormone measurement in equine samples.
Vet Clin Pathol, 45(1), 154-163.
https://doi.org/10.1111/vcp.12326 Publication
Researcher Affiliations
- School of Veterinary Sciences, University of Bristol, Langford, Bristol, UK.
- Diagnostic Laboratories, Langford Veterinary Services, University of Bristol, Bristol, UK.
- School of Veterinary Sciences, University of Bristol, Langford, Bristol, UK.
- Equine Centre, Langford Veterinary Services, University of Bristol, Bristol, UK.
- TOSOH Bioscience Ltd, The Business Centre, Redditch, UK.
- School of Veterinary Sciences, University of Bristol, Langford, Bristol, UK.
- Diagnostic Laboratories, Langford Veterinary Services, University of Bristol, Bristol, UK.
MeSH Terms
- Adrenocorticotropic Hormone / blood
- Animals
- Horse Diseases / diagnosis
- Horses
- Immunoassay / instrumentation
- Immunoassay / methods
- Immunoassay / veterinary
- Pituitary Diseases / diagnosis
- Pituitary Diseases / veterinary
- Pituitary Gland, Intermediate / physiopathology
- Prospective Studies
- Reference Values
- Reproducibility of Results
- Sensitivity and Specificity
Citations
This article has been cited 9 times.- Kirkwood NC, Hughes KJ, Stewart AJ. Prospective Case Series of Clinical Signs and Adrenocorticotrophin (ACTH) Concentrations in Seven Horses Transitioning to Pituitary Pars Intermedia Dysfunction (PPID).. Vet Sci 2022 Oct 17;9(10).
- Hinrichsen SL, Yuen KY, Dryburgh EL, Bertin FR, Stewart AJ. Short-Term Effects of Temperature and Thyrotropin-Releasing Hormone Stimulation on Adrenocorticotropin Stability in Horses.. Animals (Basel) 2022 Jan 28;12(3).
- Thane K, Uricchio C, Frank N. Effect of early or late blood sampling on thyrotropin releasing hormone stimulation test results in horses.. J Vet Intern Med 2022 Mar;36(2):770-777.
- Dunkel B, Knowles EJ, Chang YM, Menzies-Gow NJ. Influence of endocrine disease on l-lactate concentrations in blood of ponies.. J Vet Intern Med 2021 May;35(3):1582-1588.
- Morioka F, Tani N, Ikeda T, Hirokawa T, Ikeda K, Shida A, Aoki Y, Ishikawa T. Morphological and biochemical changes in the pancreas associated with acute systemic hypoxia.. Hum Cell 2021 Mar;34(2):400-418.
- Hu K, Stewart AJ, Yuen KY, Hinrichsen S, Dryburgh EL, Bertin FR. The effect of freeze-thaw cycles on determination of immunoreactive plasma adrenocorticotrophic hormone concentrations in horses.. J Vet Intern Med 2020 May;34(3):1350-1356.
- Shida A, Ikeda T, Tani N, Morioka F, Aoki Y, Ikeda K, Watanabe M, Ishikawa T. Cortisol levels after cold exposure are independent of adrenocorticotropic hormone stimulation.. PLoS One 2020;15(2):e0218910.
- McLeish SA, Burt K, Papasouliotis K. Analytical quality assessment and method comparison of immunoassays for the measurement of serum cobalamin and folate in dogs and cats.. J Vet Diagn Invest 2019 Mar;31(2):164-174.
- Banse HE, Schultz N, McCue M, Geor R, McFarlane D. Comparison of two methods for measurement of equine adrenocorticotropin.. J Vet Diagn Invest 2018 Mar;30(2):233-237.
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