Validation of 5 routine assays for serum free testosterone with a candidate reference measurement procedure based on ultrafiltration and isotope dilution–gas chromatography–mass spectrometry
Abstract
Background/method The analytical validity of free testosterone (FTe) analog immunoassays is subject to much controversy. We revisited the validation of 4 analog assays and 1 FTe calculation procedure with a metrologically traceable reference measurement procedure (RMP) based on ultrafiltration and isotope dilution-mass spectrometry for direct measurement of Te in the ultrafiltrate. To this end, we performed split-sample measurements of 40 male sera. Results Deming regression showed that 3 of the immunoassays had moderate to good correlation (0.8474 Conclusions The study demonstrated substantial differences in analytical quality of FTe assays; however, the results suggested that after extending the validation with a larger variety of samples, recalibration of some analog assays might be worth further investigation.
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Analog-based immunoassays have inadequate accuracy, bias, and dependency on T rather than free T.
“Nevertheless, inadequate accuracy, bias and dependency on T rather than free T are major drawbacks in this analog-based assays [204–206].”
From Role of sex hormone-binding globulin in the free hormone hypothesis and the relevance of free testosterone in androgen physiology (2022) · cites this paper as [204]
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- Authors
- Van Uytfanghe, K., Stöckl, D., Kaufman, J. M., Fiers, T., De Leenheer, A., & Thienpont, L. M.
- Affiliations
- Ghent University (BE)
- Ghent University Hospital (BE)
- Corresponding author
- Thienpont, L.M.
- Venue
- Clinical Biochemistry
- Publisher
- Elsevier BV
- Published
- 2005-03
- Volume
- 38
- Issue
- 3
- Pages
- 253-261
- ISSN
- 0009-9120 (ISSN-L)
- OpenAlex
- W1966986320
- Cited by
- 71
- References
- 2
- Citations by year
- 2026: 3 · 2025: 2 · 2023: 1 · 2022: 1 · 2021: 1 · 2020: 1 · 2019: 1 · 2018: 1 · 2017: 2 · 2016: 2 · 2015: 4 · 2014: 3 · 2013: 8 · 2012: 2
- FWCI
- 5.59
- Type
- journal article
- Language
- en
- Open access
- closed
- Locations
- Clinical Biochemistry (publishedVersion)
- PubMed (publishedVersion)
- Ghent University Academic Bibliography (Ghent University) (submittedVersion)
- Funders
- Multiple Sclerosis Society
- Topics
- Health Sciences › Medicine › Physiology › Clinical Laboratory Practices and Quality Control
- Health Sciences › Medicine › Endocrinology, Diabetes and Metabolism › Hormonal and reproductive studies
- Social Sciences › Decision Sciences › Statistics, Probability and Uncertainty › Scientific Measurement and Uncertainty Evaluation
- Keywords
- free testosterone, immunoassay validation, reference measurement procedure, ultrafiltration, isotope dilution mass spectrometry, testosterone measurement, matrix effects, measurement traceability
- MeSH terms
- Adult, Calibration, Carbon Isotopes, Humans, Hypogonadism, Immunoassay, Indicator Dilution Techniques, Male, Gas Chromatography-Mass Spectrometry, Middle Aged, Reference Values, Sensitivity and Specificity, Testosterone, Ultrafiltration, Reproducibility of Results
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