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Current liquid chromatography-tandem mass spectrometry (LC-MS/MS) applications for circulating androgen measurements are technically diverse. Previously, variable results have been reported for testosterone. Data are scarce for androstenedione and absent for dehydroepiandrosterone sulfate (DHEAS). We assessed the agreement of androstenedione, DHEAS and testosterone LC-MS/MS measurements among nine European centers and explored benefits of calibration system unification. Androgens were measured twice by laboratory-specific procedures in 78 patient samples and in EQA materials. Results were obtained by in-house and external calibration. Intra- and inter-laboratory performances were valued. Intra-laboratory CVs ranged between 4.2–13.2 % for androstenedione, 1.6–10.8 % for DHEAS, and 4.3–8.7 % and 2.6–7.1 % for female and male testosterone, respectively. Bias and trueness in EQA materials were within ±20 %. Median inter-laboratory CV with in-house vs. external calibration were 12.0 vs. 9.6 % for androstenedione (p<0.001), 7.2 vs. 4.9 % for DHEAS (p<0.001), 6.4 vs. 7.6 % for female testosterone (p<0.001) and 6.8 and 7.4 % for male testosterone (p=0.111). Median bias vs. all laboratory median with in-house and external calibration were −13.3 to 20.5 % and −4.9 to 18.7 % for androstenedione, −10.9 to 4.8 % and −3.4 to 3.5 % for DHEAS, −2.7 to 6.5 % and −11.3 to 6.6 % for testosterone in females, and −7.0 to 8.5 % and −7.5 to 11.8 % for testosterone in males, respectively. Methods showed high intra-laboratory precision but variable bias and trueness. Inter-laboratory agreement was remarkably good. Calibration system unification improved agreement in androstenedione and DHEAS, but not in testosterone measurements. Multiple components, such as commutability of calibrators and EQA materials and internal standard choices, likely contribute to inter-laboratory variability. [ABSTRACT FROM AUTHOR]

Background Measurement of serum dexamethasone during the overnight dexamethasone-suppression test has been recommended to reduce false-positive results when investigating Cushing's syndrome or increasingly commonly found adrenal incidentalomas. Despite this, there remains a paucity of well-validated dexamethasone methods currently available. Here, we describe the development of a rapid and sensitive liquid chromatography tandem mass spectrometry serum dexamethasone assay and verify its utility in a cohort of postmenopausal females. Method Isotopically labelled internal standard was added to samples prior to supported liquid extraction. Extracts were analysed using liquid chromatography tandem mass spectrometry in the positive electrospray ionization mode. Multiple reaction monitoring was used to detect dexamethasone and its corresponding internal standard transitions. Normal healthy postmenopausal women ( n = 95) were recruited and underwent an overnight dexamethasone suppression test, with serum dexamethasone and cortisol measurements at 09:00 after administration of oral dexamethasone 1 mg at 23:00 the night before. Results Mean intra- and inter-assay imprecision were 4.1% and 2.9%, respectively, for dexamethasone concentrations of 1.5, 6.0 and 12.0 nmol/L. Matrix effects were found to be negligible at 106-109% with recovery ranging from 96 to 100%. The limit of quantitation was 0.25 nmol/L, and structural analogue analysis proved the method to be robust against interferences. Applying a serum dexamethasone cut-off of >3.3 nmol/L was associated with a serum cortisol ≤50 nmol/L in 84/95 individuals. Conclusion We have developed a sensitive and robust liquid chromatography tandem mass spectrometry method for the quantitation of serum dexamethasone. The method can be used to identify false-positive results during the overnight dexamethasone suppression test or for pharmacokinetic studies. [ABSTRACT FROM AUTHOR]

7α-Hydroxy-4-cholesten-3-one (C4) is the common intermediary of both primary bile acids. C4 is recommended by the British Society of Gastroenterology for the investigation of bile acid diarrhoea (BAD) in patients with chronic diarrhoea. This project aimed to develop and validate an assay to quantitate C4 in serum and assess the stability of C4 in unseparated blood.Accuracy was underpinned by calibrating to quantitative nuclear magnetic resonance analysis. C4 was analysed in a 96-well plate format with a deuterated C4 internal standard and liquid-liquid extraction. Validation followed the 2018 Food and Drug Administration guidelines. To assess C4 stability, healthy volunteers (n=12) donated 8 fasted samples each. Samples were incubated at 20 °C for up to 72 h and retrieved, centrifuged, aliquoted and frozen for storage at different time points prior to C4 analysis.The C4 method demonstrated excellent analytical performance and passed all validation criteria. The method was found to be accurate, precise, free from matrix effects and interference. After 72 h of delayed sample separation, C4 concentration gradually declined by up to 14 % from baseline. However, the change was not significant for up to 12 h.We present a robust method of analysing serum C4, offering a convenient alternative to 75SeHCAT for BAD investigation. C4 was found to decline in unseparated blood over time; however, after 12 h the mean change was <5 % from baseline. Our results suggest C4 is suitable for collection from both primary and secondary care prior to gastroenterology referral. [ABSTRACT FROM AUTHOR]

Background: Biochemical hyperandrogenism is a hallmark and diagnostic feature of polycystic ovary syndrome (PCOS). However, the most accurate androgen measurement for assessing biochemical hyperandrogenism in PCOS diagnosis remains uncertain., Objective and Rationale: This systematic review aimed to assess different androgen measures [including total testosterone (TT), calculated free testosterone (cFT), free androgen index (FAI), androstenedione (A4), dehydroepiandrosterone sulfate (DHEAS), and dihydrotestosterone (DHT)] for accuracy in diagnosing biochemical hyperandrogenism in women with PCOS, to inform the 2023 International PCOS Evidence-based Guidelines., Search Methods: To update evidence from the 2018 International PCOS Guidelines, a systematic search from 3 July 2017 to 23 June 2023 was conducted across Medline (Ovid), CINAHL, all EBM, EMBASE, and PsycInfo for articles evaluating androgens in the diagnosis of biochemical hyperandrogenism. The revised Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) was used to assess the risk of bias and applicability. A diagnostic test accuracy meta-analysis was performed using STATA 18 software. Summary sensitivity and specificity were calculated with 95% CIs using the bivariate model, while the hierarchical summary receiver operating characteristics (ROC) model was used to produce a summary ROC curve., Outcomes: Of 23 studies reviewed, 18 were included in the meta-analysis, with data from 2857 participants (1650 with PCOS and 1207 controls). For diagnosing biochemical hyperandrogenism in PCOS, the pooled sensitivity, specificity, and AUC with 95% CI were for TT: 0.74 (0.63-0.82), 0.86 (0.77-0.91), and 0.87 (0.84-0.90); cFT: 0.89 (0.69-0.96), 0.83 (0.79-0.86), and 0.85 (0.81-0.88); FAI: 0.78 (0.70-0.83), 0.85 (0.76-0.90), and 0.87 (0.84-0.90); A4: 0.75 (0.60-0.86), 0.71 (0.51-0.85), and 0.80 (0.76-0.83); and DHEAS: 0.75 (0.61-0.85), 0.67 (0.48-0.81), and 0.77 (0.73-0.81), respectively. In subgroup analyses, liquid chromatography with tandem mass spectrometry (LC-MS/MS) had superior sensitivity for measuring cFT, FAI, A4, and DHEAS, and superior specificity for measuring TT, cFT, and FAI, compared to the direct immunoassay method., Wider Implications: Our results directly informed the 2023 International PCOS Guideline recommendations to use TT and FT as the first-line laboratory tests to assess biochemical hyperandrogenism in the diagnosis of PCOS. cFT should be assessed by equilibrium dialysis or ammonium sulfate precipitation, or calculated using FAI. If TT or cFT are not elevated, A4 and DHEAS could also be considered, noting their poorer specificity. Laboratories should utilize LC-MS/MS for androgen measurement given its high accuracy. Future studies should focus on establishing optimal normative cut-off values in large, unselected, and ethnically diverse cohorts of women., Registration Number: The review protocol was prepublished in the 2023 PCOS Guideline Technical Report (https://www.monash.edu/&#95;&#95;data/assets/pdf&#95;file/0010/3379591/TechnicalReport-2023.pdf)., (© The Author(s) 2024. Published by Oxford University Press on behalf of European Society of Human Reproduction and Embryology.)