A novel LC-MS/MS-based assay for the simultaneous quantification of aldosterone-related steroids in human urine

Nora Vogg; Lydia Kürzinger; Sabine Kendl; Christina Pamporaki; Graeme Eisenhofer; Christian Adolf; Stefanie Hahner; Martin Fassnacht; Max Kurlbaum

doi:10.1515/cclm-2023-0250

A novel LC-MS/MS-based assay for the simultaneous quantification of aldosterone-related steroids in human urine

Clin Chem Lab Med. 2023 Nov 28;62(5):919-928. doi: 10.1515/cclm-2023-0250. Print 2024 Apr 25.

Authors

Nora Vogg^{1

2}, Lydia Kürzinger¹, Sabine Kendl^{1

2}, Christina Pamporaki³, Graeme Eisenhofer³, Christian Adolf⁴, Stefanie Hahner¹, Martin Fassnacht^{1

2}, Max Kurlbaum^{1

2}

Affiliations

¹ Department of Internal Medicine I, Division of Endocrinology and Diabetes, University Hospital, University of Würzburg, Würzburg, Germany.
² Central Laboratory, Core Unit Clinical Mass Spectrometry, University Hospital Würzburg, Würzburg, Germany.
³ Department of Internal Medicine III, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.
⁴ Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, LMU München, Munich, Germany.

PMID: 38008792
DOI: 10.1515/cclm-2023-0250

Abstract

Objectives: Primary aldosteronism is the most common cause of endocrine hypertension and is associated with significant cardiovascular morbidities. The diagnostic workup depends on determinations of plasma aldosterone and renin which are highly variable and associated with false-positive and false-negative results. Quantification of aldosterone in 24 h urine may provide more reliable results, but the methodology is not well established. We aimed to establish an assay for urinary aldosterone and related steroids with suitability for clinical routine implementation.

Methods: Here, we report on the development and validation of a quantitative LC-MS/MS method for six urinary steroids: aldosterone, cortisol, 18-hydroxycorticosterone, 18-hydroxycortisol, 18-oxocortisol, tetrahydroaldosterone. After enzymatic deconjugation, total steroids were extracted using SepPak tC18 plates and quantified in positive electrospray ionization mode on a QTRAP 6500+ mass spectrometer.

Results: Excellent linearity was demonstrated with R²>0.998 for all analytes. Extraction recoveries were 89.8-98.4 % and intra- and inter-day coefficients of variations were <6.4 and <9.0 %, establishing superb precision. Patients with primary aldosteronism (n=10) had higher mean 24 h excretions of aldosterone-related metabolites than normotensive volunteers (n=20): 3.91 (95 % CI 2.27-5.55) vs. 1.92 (1.16-2.68) µmol/mol for aldosterone/creatinine, 2.57 (1.49-3.66) vs. 0.79 (0.48-1.10) µmol/mol for 18-hydroxycorticosterone/creatinine, 37.4 (13.59-61.2) vs. 11.61 (10.24-12.98) µmol/mol for 18-hydroxycortisol/creatinine, 1.56 (0.34-2.78) vs. 0.13 (0.09-0.17) µmol/mol for 18-oxocortisol/creatinine, and 21.5 (13.4-29.6) vs. 7.21 (4.88-9.54) µmol/mol for tetrahydroaldosterone/creatinine.

Conclusions: The reported assay is robust and suitable for routine clinical use. First results in patient samples, though promising, require clinical validation in a larger sample set.

Keywords: aldosterone; mass spectrometry; method validation; primary aldosteronism; urinary steroids.

MeSH terms

Aldosterone*
Chromatography, Liquid / methods
Creatinine
Humans
Hyperaldosteronism* / diagnosis
Liquid Chromatography-Mass Spectrometry
Tandem Mass Spectrometry / methods

Substances

Aldosterone
Creatinine