Harmonization of Immunoassay Reference Intervals with LC-MS/MS for Total and Calculated Free Testosterone Measurement

madman

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* harmonized reference ranges for total and calculated free testosterone in adults using the Siemens Atellica immunoassay, validated against a reference method.

* Reference intervals were adopted from the reference laboratory and verified using 20 male and 20 female healthy samples.

* Harmonized reference intervals for total and calculated free testosterone, validated on Siemens Atellica, offer consistent results comparable to LC-MS/MS



Total testosterone: Male 240-950 ng/dL, Female 8-60 ng/dL

Free testosterone: Male 2.29-20.7 ng/dL, Female 0-1.08 ng/dL.




Abstract

Background


Management of male hypogonadism relies on accurate serum testosterone testing and reference values. This study aimed to establish harmonized reference ranges for total and calculated free testosterone in adults using the Siemens Atellica immunoassay, validated against a reference method.


Methods

The Siemens Atellica IM total testosterone assay is a fully automated competitive chemiluminescent immunoassay. We conducted 25 de-identified serum samples. Inter-laboratory correlation studies for total testosterone were performed on in-house Siemens Atellica and liquid chromatography-tandem mass spectrometry (LC-MS/MS) at a reference laboratory. Free testosterone was calculated using the International Society for the Study of the Aging Male (ISSAM) Free Testosterone calculator, which can be accessed from the ISSAM website, http://www.issam.ch/freetesto.htm, using the assayed concentrations of testosterone and Sex Hormone Binding Globulin (SHBG) on the Siemens Atellica IM system. The Siemens Atellica IM SHBG assay is a sandwich monoclonal immunoassay. Calculated free testosterone was compared with LC-MS/MS. Deming and linear regression, and Bland-Altman plot were employed for data analysis. Reference intervals were adopted from the reference laboratory and verified using 20 male and 20 female healthy samples. Total testosterone: Male 240-950 ng/dL, Female 8-60 ng/dL; Free testosterone: Male 2.29-20.7 ng/dL, Female 0-1.08 ng/dL.


Results

Strong correlations were observed between Siemens Atellica and LC-MS/MS for total testosterone (R^2 = 0.9915, slope = 0.988, intercept = 35) and for calculated free testosterone (R^2 = 0.9645, slope = 0.988, intercept = -0.4). Adopted reference intervals were verified using local healthy samples.


Conclusions

Harmonized reference intervals for total and calculated free testosterone, validated on Siemens Atellica, offer consistent results comparable to LC-MS/MS. This study demonstrates the feasibility of establishing standardized reference ranges for testosterone assays across laboratories.
 

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TRT Hormone Predictor

Predict estradiol, DHT, and free testosterone levels based on total testosterone

⚠️ Medical Disclaimer

This tool provides predictions based on statistical models and should NOT replace professional medical advice. Always consult with your healthcare provider before making any changes to your TRT protocol.

ℹ️ Input Parameters

Normal range: 300-1000 ng/dL

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Understanding Your Hormones

Estradiol (E2)

A form of estrogen produced from testosterone. Important for bone health, mood, and libido. Too high can cause side effects; too low can affect well-being.

DHT

Dihydrotestosterone is a potent androgen derived from testosterone. Affects hair growth, prostate health, and masculinization effects.

Free Testosterone

The biologically active form of testosterone not bound to proteins. Directly available for cellular uptake and biological effects.

Scientific Reference

Lakshman KM, Kaplan B, Travison TG, Basaria S, Knapp PE, Singh AB, LaValley MP, Mazer NA, Bhasin S. The effects of injected testosterone dose and age on the conversion of testosterone to estradiol and dihydrotestosterone in young and older men. J Clin Endocrinol Metab. 2010 Aug;95(8):3955-64.

DOI: 10.1210/jc.2010-0102 | PMID: 20534765 | PMCID: PMC2913038

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