Agreement of Immunoassay and Tandem Mass Spectrometry in the Analysis of Cortisol and Free T4: Interpretation and Implications for Clinicians
Open accessAbstract
Objective. To quantify differences in results obtained by immunoassays (IAs) and tandem mass spectrometry (MSMS) for cortisol and free thyroxine (FT4).Design&Patients. Cortisol was measured over 60 minutes following a standard ACTH stimulation test (n=80); FT4 was measured over time in two cohorts of pregnant (n=57), and nonpregnant (n=28) women.Measurements. Samples were analyzed with both IA and MSMS.Results. Results for cortisol by the two methods tended to agree, but agreement weakened over the 60-minute test and was worse for higher (more extreme) concentrations. The results for FT4 depended on the method. IA measurements tended to agree with MSMS measurements when values fell within “normal levels”, but agreement was not constant across trimester in pregnant women and was poorest for the extreme (low/high) concentrations. Correlations between MSMS measurements and the difference between MSMS and IA results were strong and positive (0.411< r <0.823; allP<.05).Conclusions. IA and MSMS provide different measures of cortisol and FT4 at extreme levels, where clinical decision making requires the greatest precision. Agreement between the methods is inconsistent over time, is nonlinear, and varies with the analyte and concentrations. IA-based measurements may lead to erroneous clinical decisions.
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References 28 · Cited by 64
Research works printed but not linked: 3
- [1]Nunnally JC Bernstein IH Psychometric Theory 1994 3rd edition New York, NY, USA McGraw-Hil
- [9]Chrousos GP Margioris AN Adrenal Disorders 2001 Totowa, NJ, USA Humana Press
- [26]Gu J Soldin SJ Simultaneous quantification of free triidothyronine and free thyroxine by tandem mass spectrometry Clinical Biochemistry 2007 53 6 p. D99 17936741
- Authors
- Tractenberg, R. E., Jonklaas, J., & Soldin, S. J.
- Affiliations
- Georgetown University Medical Center (US)
- Corresponding author
- Tractenberg, Rochelle E.
- Venue
- International Journal of Analytical Chemistry
- Publisher
- Wiley
- Published
- 2010
- Volume
- 2010
- Pages
- 1-7
- ISSN
- 1687-8760 (ISSN-L)
- 1687-8779
- PMC
- PMC2913524
- OpenAlex
- W2054819383
- Cited by
- 64
- References
- 28
- Citations by year
- 2025: 1 · 2024: 2 · 2023: 2 · 2022: 1 · 2021: 6 · 2020: 8 · 2019: 9 · 2018: 10 · 2017: 7 · 2016: 5 · 2015: 3 · 2014: 4 · 2013: 2 · 2012: 1
- FWCI
- 1.28
- Type
- journal article
- Language
- en
- Open access
- gold
- doi.org
- Locations
- International Journal of Analytical Chemistry (publishedVersion, cc-by)
- PubMed Central (publishedVersion, cc-by)
- PubMed (publishedVersion)
- DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
- Funders
- National Center for Research Resources (M01RR1329, K01AG027172, U10HD45993-02)
- National Institute on Aging (M01RR1329, K01AG027172, U10HD45993-02)
- National Institute of Child Health and Human Development (M01RR1329, K01AG027172, U10HD45993-02)
- Topics
- Health Sciences › Medicine › Physiology › Clinical Laboratory Practices and Quality Control
- Health Sciences › Medicine › Endocrinology, Diabetes and Metabolism › Adrenal Hormones and Disorders
- Health Sciences › Medicine › Endocrinology, Diabetes and Metabolism › Thyroid Disorders and Treatments
- Keywords
- cortisol, free thyroxine, immunoassay, tandem mass spectrometry, measurement agreement, ACTH stimulation test, pregnancy, pregnancy trimesters, clinical decision-making
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