Clinical measurement of steroid metabolism

Improving LC-MS/MS measurements of steroids with differential mobility spectrometry

Introduction

Steroid measurements are important for diagnosis and monitoring of many conditions and treatment regiments; however, due to structural and chemical similarities amongst steroids, these analyses are challenging, even for highly specific techniques such as liquid chromatography-tandem mass spectrometry (LC-MS/MS). Differential mobility spectrometry (DMS) has the potential to improve these analyses by providing an orthogonal and complementary separation technique.

Methods

Initially, the potential for DMS to improve signal-to-noise ratio (S/N) and reduce interference was tested by comparing chromatograms acquired with and without DMS when performing measurements of six different steroids. Subsequently, a full clinical validation of cortisol and cortisone in urine was performed with the LC-DMS-MS/MS method.

Results and Discussion

DMS significantly reduced interferences observed in the chromatograms and boosted S/N by between 1.6 and 13.8 times. Additionally, DMS improved the agreement between quantifier/qualifier fragment ion results for cortisol and cortisone as indicated by the increase in R2 from approximately 0.81 to 0.98. All validation studies met acceptance criteria and we observed exceptional analytical performance in terms of precision, with % CVs less than 8%.

Conclusions

DMS improved the specificity of the steroid measurements by reducing interferences and improving S/N. The validation studies prove that these benefits did not come at the expense of other aspects of analytical performance. This study indicates that DMS has the potential to benefit not just clinical measurements of challenging analytes, but many clinical LC-MS/MS analyses.

The toxic mechanism of 6:2 Cl-PFESA in adolescent male rats: Endocrine disorders and liver inflammation regulated by the gut microbiota-gut-testis/liver axis

In previous studies, 6:2 chlorinated polyfluorinated ether sulfonic acid (6:2 Cl-PFESA), a perfluorooctanesulfonate alternative, has been demonstrated to be toxic to mammals. However, the toxic mechanism of 6:2 Cl-PFESA in mammals is unknown. Herein, adolescent male rats were administered 50 μg/kg/Day 6:2 Cl-PFESA for 28 days (oral gavage) to estimate the toxicity of 6:2 Cl-PFESA and investigate its toxic mechanism. Significant changes in some hematological indicators (e.g., aspartate transaminase and neutrophils) and liver sections (inflammatory cell infiltration) indicated that 6:2 Cl-PFESA exposure caused rat hepatotoxicity. Six steroid hormones (e.g., testosterone, progesterone, and cortisol) in serum and thirteen genes in testicles (related to the pathway of steroid hormone biosynthesis) were significantly regulated in 6:2 Cl-PFESA-treated rats. This suggested that 6:2 Cl-PFESA induced rat endocrine disorders. Compared to the controls, the mean relative abundance of Ruminococcaceae, Pasteurellaceae, Micrococcaceae, and Desulfovibrionaceae was significantly regulated by 1.3-, 0.40-, 0.32-, and 3.2-fold in the 6:2 Cl-PFESA rats, respectively. The 6:2 Cl-PFESA treatment also significantly disturbed 47 gut metabolites (29 upregulated and 18 downregulated), mainly bile acids, short-chain fatty acids, and amino acids. In summary, 6:2 Cl-PFESA induced endocrine disorders and liver inflammation in rats by altering the gut microbiota-gut-testis/liver axis. This study first reveals the toxic mechanism of 6:2 Cl-PFESA in mammals through a multiomics approach and provides comprehensive insight into the toxic mechanism of 6:2 Cl-PFESA.

The Biosynthesis of Enzymatically Oxidized Lipids

Enzymatically oxidized lipids are a specific group of biomolecules that function as key signaling mediators and hormones, regulating various cellular and physiological processes from metabolism and cell death to inflammation and the immune response. They are broadly categorized as either polyunsaturated fatty acid (PUFA) containing (free acid oxygenated PUFA "oxylipins", endocannabinoids, oxidized phospholipids) or cholesterol derivatives (oxysterols, steroid hormones, and bile acids). Their biosynthesis is accomplished by families of enzymes that include lipoxygenases (LOX), cyclooxygenases (COX), cytochrome P450s (CYP), and aldo-keto reductases (AKR). In contrast, non-enzymatically oxidized lipids are produced by uncontrolled oxidation and are broadly considered to be harmful. Here, we provide an overview of the biochemistry and enzymology of LOXs, COXs, CYPs, and AKRs in humans. Next, we present biosynthetic pathways for oxylipins, oxidized phospholipids, oxysterols, bile acids and steroid hormones. Last, we address gaps in knowledge and suggest directions for future work.

Development and validation of LC-ESI-MS/MS methods for quantification of 27 free and conjugated estrogen-related metabolites

An imbalance in the estrogen metabolism has been associated with an increased risk of breast cancer development. Evaluation of the estrogen biotransformation capacity requires monitoring of various estrogen metabolites. Up to now, only some estrogen metabolites could be measured in urine. However, in order to offer tailor made nutritional support or therapies, a complete estrogen metabolite profile is required in order to identify specific deficiencies in this pathway for each patient individually. Here, we focused on this need to quantify as many as possible of the estrogen-related metabolites excreted in urine. The method was developed to quantify 27 estrogen-related metabolites in small urine quantities. This entailed sample clean-up with a multi-step solid phase extraction procedure, derivatisation of the metabolites in the less water-soluble fraction through dansylation, and analyses using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The metabolites accurately quantified by the method devised included parent estrogens, hydroxylated and methylated forms, metabolites of the 16α-hydroxyestrogen pathway, sulphate and glucuronide conjugated forms, precursors and a related steroid hormone. This method was validated and enabled quantification in the high picograms and low nanograms per millilitre range. Finally, analyses of urine samples confirmed detection and quantification of each of the metabolites.

Serum Cortisol Levels via Radioimmunoassay vs Liquid Chromatography Mass Spectrophotometry in Healthy Control Subjects and Patients With Adrenal Incidentalomas

Background

Adrenal incidentalomas (AIs) are present in 4% of adults. As many as 30% may secrete cortisol autonomously in the absence of specific signs of overt hypercortisolism, in a phenomenon called subclinical hypercortisolism (SH). Diagnosis of SH is established by serum cortisol resistance to dexamethasone suppression.

Methods

We compared serum cortisol concentrations, as determined by radioimmunoassay (RIA) and liquid chromatography/tandem mass spectronomy (LC/MS-MS), in 73 patients with AI group (52 with unilateral AI) and 34 control subjects in 3 scenarios: basal; after 1-mg dexamethasone suppression; and after 0.25-mg stimulation with cosyntropin, a synthetic derivative of adrenocorticotropic hormone (ACTH). To bolster evidence for the diagnosis of SH, we also measured salivary cortisol levels at 11 PM and after DST, as well as plasma ACTH and serum dehydroepiandrosterone sulfate (DHEA-S) levels.

Results

We observed significant positive correlation (r = 0.9345, P <.001) for all 318 pairs of serum cortisol values, as measured by both methods.

Conclusions

Serum cortisol concentrations in patients with AI and in control subjects were very similar, as measured by RIA and LC/MS-MS.

Steroid hormone profiles plus α-fetoprotein for diagnosing primary liver cancer by liquid chromatography tandem mass spectrometry

BACKGROUND

Primary liver cancer (PLC) is one of the most common malignant tumors world-wide but its pathogenesis is unclear. We suggest that steroid hormones may offer diagnostic information for PLC.

METHODS

Using liquid chromatography (UPLC) and tandem mass spectrometry (MS/MS), we quantified 7 endogenous steroids in 66 PLC human serum samples, 59 liver cirrhosis (LC) samples, and 65 healthy volunteers (HV). Data were assessed chemometrically and with Mann-Whitney U tests and partial least squares discriminant analysis (PLS-DA).

RESULTS

For PLC patients, androgens were low and estrogen was high. PLS-DA analysis discriminated between healthy subjects and cancer patients using (estrone+estradiol)/testosterone ratios. Moreover, cirrhosis patients were also distinguished with receiver operating characteristic curves indicating the specificity and sensitivity of our current approach.

CONCLUSIONS

Steroid hormone profiling by UPLC-MS/MS may be promising for early diagnosis of PLC but investigations with more patients and steroids are required to confirm the utility of these biomarkers for clinical applications.

Bioanalytical LC-MS Method for the Quantification of Plasma Androgens and Androgen Glucuronides in Breast Cancer

The physiological and pathological development of the breast is strongly affected by the hormonal milieu consisting of steroid hormones. Mass spectrometry (MS) technologies of high sensitivity and specificity enable the quantification of androgens and consequently the characterization of the hormonal status. The aim of this study is the assessment of plasma androgens and androgen glucuronides, in the par excellence hormone-sensitive tissue of the breast, through the application of liquid chromatography-mass spectrometry (LC-MS). A simple and efficient fit-for-purpose method for the simultaneous identification and quantification of dehydroepiandrosterone sulfate (DHEAS), androstenedione (A4), androsterone glucuronide (ADTG) and androstane-3α, 17β-diol-17-glucuronide (3α-diol-17G) in human plasma was developed and validated. The presented method permits omission of derivatization, requires a single solid-phase extraction procedure and the chromatographic separation can be achieved on a single C18 analytical column, for all four analytes. The validated method was successfully applied for the analysis of 191 human plasma samples from postmenopausal women with benign breast disease (BBD), lobular neoplasia (LN), ductal carcinoma in situ and invasive ductal carcinoma (IDC). DHEAS plasma levels exhibited significant differences between LN, IDC and BBD patients (P < 0.05). Additionally, ADTG levels were significantly higher in patients with LN compared with those with BBD (P < 0.05).

A guide to understanding the steroid pathway: new insights and diagnostic implications

Steroid analysis has always been complicated requiring a clear understanding of both the clinical and analytical aspects in order to accurately interpret results. The literature relating to this specialised area spans many decades and the intricacies of the steroid pathway have evolved with time. A number of key changes, including discovery of the alternative androgen pathway, have occurred in the last decade, potentially changing our understanding and approach to investigating disorders of sexual development. Such investigation usually occurs in specialised paediatric centres and although preterm infants represent only a small percentage of the patient population, consideration of the persistence of the foetal adrenal zone is an additional important consideration when undertaking steroid hormone investigations. The recent expanded role of mass spectrometry and molecular diagnostic methods provides significant improvements for accurate steroid quantification and identification of enzyme deficiencies. However analysis of steroids and interpretation of results remain complicated. This review aims to provide an insight into the complexities of steroid measurement in children and offers an updated guide to interpretation, of serum and urine steroids through the presentation of a refined steroid pathway.

Androgen glucuronides analysis by liquid chromatography tandem-mass spectrometry: could it raise new perspectives in the diagnostic field of hormone-dependent malignancies?

Breast and prostate constitute organs of intense steroidogenic activity. Clinical and epidemiologic data provide strong evidence on the influence of androgens and estrogens on the risk of typical hormone-dependent malignancies, like breast and prostate cancer. Recent studies have focused on the role of androgen metabolites in regulating androgen concentrations in hormone-sensitive tissues. Steroid glucuronidation has been suggested to have a prominent role in controlling the levels and the biological activity of unconjugated androgens. It is well-established that serum levels of androgen glucuronides reflect androgen metabolism in androgen-sensitive tissues. Quantitative analysis of androgen metabolites in blood specimens is the only minimally invasive approach permitting an accurate estimate of the total pool of androgens. During the past years, androgen glucuronides analysis most often involved radioimmunoassays (RIA) or direct immunoassays, both methods bearing serious limitations. However, recent impressive technical advances in mass spectrometry, and particularly in high performance liquid chromatography coupled with mass spectrometry (LC-MS/MS), have overcome these drawbacks enabling the simultaneous, quantitative analysis of multiple steroids even at low concentrations. Blood androgen profiling by LC-MS/MS, a robust and reliable technique of high selectivity, sensitivity, specificity, precision and accuracy emerges as a promising new approach in the study of human pathology. The present review offers a contemporary insight in androgen glucuronides profiling through the application of LC-MS/MS, highlighting new perspectives in the study of steroids and their implication in hormone-dependent malignancies.

Ultra performance liquid chromatography-tandem mass spectrometry method for profiling of steroid metabolome in human tissue

In humans, steroids play a broad and vital role in regulation of gene expression, secondary sexual characteristics, maturation, reproduction, cardiovascular health, neurological functions, etc., but imbalance in steroid metabolism is also linked to development and progression of many diseases, such as cancer, neurodegenerative diseases, and cardiovascular diseases. Hence, measurement of steroids in biological samples is essential to monitor human health. Currently, there is radioimmunoassay, gas chromatography-mass spectrometry (GC/MS), and liquid chromatography-mass spectrometry (LC-MS) methods developed for steroid measurements in biological samples. However, these methods require elaborate sample preparation procedures and have concerns(s) related to reproducibility, dynamic range, time, costs, and most importantly the total coverage of steroids. Also currently, there is no method available for comprehensive steroid profiling in a single LC-MS run that includes androgens, corticosteroids, progestogens, estrogens, estrogen metabolites, estrogen conjugates, and estrogen-DNA adducts as well as exogenous steroid derivatives. Here, I present a global steroid metabolic profiling method based on liquid-liquid extraction (LLE) followed by ultra performance liquid chromatography (UPLC)-tandem mass spectrometry (MS/MS) for simultaneous measurement of over 100 indigenous as well as exogenous steroids in about 12 min, without derivatization. The method was successfully applied to determine steroid hormone levels in the breast tissue of healthy women. Overall presence of all major classes of steroids as well as estrogen derivatives was detected in breast tissue.

Liquid chromatography-tandem mass spectrometry analysis of human adrenal vein corticosteroids before and after adrenocorticotropic hormone stimulation

CONTEXT

Although steroid hormones produced by the adrenal gland play critical roles in human physiology, a detailed quantitative analysis of the steroid products has not been reported. The current study uses a single methodology (liquid chromatography-tandem mass spectrometry, LC-MS/MS) to quantify ten corticosteroids in adrenal vein (AV) samples pre- and post-adrenocorticotropic hormone (ACTH) stimulation.

DESIGN/METHODS

Three men and six women with a diagnosis of an adrenal aldosterone-producing adenoma (APA) were included in the study. Serum was collected from the iliac vein (IV) and the AV contralateral to the diseased adrenal. Samples were collected, before and after administration of ACTH. LC-MS/MS was then used to quantify serum concentrations of unconjugated corticosteroids and their precursors.

RESULTS

Prior to ACTH stimulation, the four most abundant steroids in AV were cortisol (90%), cortisone (4%), corticosterone (3%) and 11-deoxycortisol (0.8%). Post-ACTH administration, cortisol remained the major adrenal product (79%); however, corticosterone became the second most abundantly produced adrenal steroid (11%) followed by pregnenolone (2.5%) and 17α-hydroxypregnenolone (2%). ACTH significantly increased the absolute adrenal output of all ten corticosteroids measured (P < 0.05). The four largest post-ACTH increases were pregnenolone (300-fold), progesterone (199-fold), 17α-hydroxypregnenolone (187-fold) and deoxycorticosterone (82-fold).

CONCLUSION

Using LC-MS/MS, we successfully measured 10 corticosteroids in peripheral and AV serum samples under pre- and post-ACTH stimulation. This study demonstrates the primary adrenal steroid products and their response to ACTH.

Activities of aldo-keto reductase 1 enzymes on two inhaled corticosteroids: implications for the pharmacological effects of inhaled corticosteroids

Inhaled corticosteroids (ICS) are a mainstay anti-inflammatory therapy for the management of asthma. ICS are synthetic glucocorticoids that are structurally similar to the natural active human glucocorticoid cortisol. Steroid transforming enzymes of the aldo-keto reductase (AKR) family, namely AKR1D1 (5β-steroid reductase) and AKR1C1-4 (ketosteroid reductases) are implicated in the systemic metabolism of cortisol in liver. In this study, the activities of these AKR1 enzymes on cortisol and two ICS compounds budesonide (BUD) and flunisolide (FLU) were investigated. It was found that the catalytic efficiency of AKR1D1 for the reduction of the double bond in cortisol was 4- and 10-fold higher than the catalytic efficiencies of AKR1D1 with FLU and BUD, respectively. This suggests that compared to cortisol, for which the 5β-reduction is a major metabolic pathway, a lower degree of systemic (hepatic) metabolism of BUD and FLU via AKR1D1 takes place. In addition, BUD potently inhibited AKR1D1 and AKR1C4, the key steroid metabolizing enzymes in liver, which may disrupt endogenous steroid hormone metabolism and thus contribute to BUD-induced systemic effects. Activities of AKR1C1-3 on cortisol and the two ICS compounds (targeting the 20-keto group) suggest these enzymes may be involved in the local (lung) metabolism of these glucocorticoids.

Steroid hormone analysis by tandem mass spectrometry

BACKGROUND

New high-performance liquid chromatography/tandem mass spectrometry (LC-MS/MS) methods are among the most successful approaches to improve specificity problems inherent in many immunoassays.

CONTENT

We emphasize problems with immunoassays for the measurement of steroids and review the emerging role of LC-MS/MS in the measurement of clinically relevant steroids. The latest generation of tandem mass spectrometers has superior limits of quantification, permitting omission of previously employed derivatization steps. The measurement of steroid profiles in the diagnosis and treatment of congenital adrenal hyperplasia, adrenal insufficiency, chronic pelvic pain and prostatitis, oncology (breast cancer), and athletes has important new applications.

CONCLUSIONS

LC-MS/MS now affords the specificity, imprecision, and limits of quantification necessary for the reliable measurement of steroids in human fluids, enhancing diagnostic capabilities, particularly when steroid profiles are available.

Screening of boldenone and methylboldenone in bovine urine using disposable electrochemical immunosensors

Electrochemical based immunosensors for the detection of boldenone and methylboldenone in bovine urine were described in this paper. The immunosensors were fabricated by immobilizing boldenone-bovine serum albumin conjugate on the surface of screen-printed electrodes (SPEs), and followed by the competition between the free analyte and coating conjugate with corresponding antibodies. The use of anti-species IgG-horseradish peroxidase conjugate determined the degree of competition. The electrochemical technique chosen was chronoamperometry, performed at a potential of +100 mV whereby the product of the catalysis of 3,3',5,5'-tetramethylbenzidine undergoes reduction produced by the enzyme label. The limits of detection of assay were 30.9+/-4.3 pg ml(-1) for boldenone and 120.2+/-8.2 pg ml(-1) for methylboldenone, respectively. Results of repeated analysis of each androgen carried out using three different batches of electrodes indicate suitable repeatability (EC(50)=1.0+/-0.3 ng ml(-1)(n=3, N=3), R(2)=0.969, R.S.D.=9.6% for boldenone and 1.5+/-0.3 ng ml(-1), 0.971, 10.5% for methylboldenone, respectively). Urine samples were determined directly after a single dilution step, omitting extraction and hydrolysis. This method offers the advantage to pick up both boldenone and its major metabolites in an efficient manner due to the high cross-reactivity pattern of alpha-boldenone with this antibody. The concentration of methylboldenone in urine detected by developed methods does indicate methylboldenone administration to heifers. Gas chromatography coupled to mass spectrometry analysis was performed to quantitate the individual metabolites present in urine samples, and results were validated with both ELISA and immunosensor data.

Cortisol, aldosterone, cortisol precursor, androgen and endogenous ACTH concentrations in dogs with pituitary-dependant hyperadrenocorticism treated with trilostane

Trilostane is thought to be a competitive inhibitor of the 3beta-hydroxysteroid dehydrogenase (3beta-HSD), an essential enzyme system for the synthesis of cortisol, aldosterone and androstenedione. Due to its reliable clinical efficacy, trilostane is increasingly used to treat dogs with pituitary-dependant hyperadrenocorticism (PDH). The objective of our study was to investigate the effect of trilostane on precursor concentrations located before (17alpha-OH-pregnenolone, dehydroepiandrostenedione) and after (17alpha-OH-progesterone, androstenedione, 11-deoxycortisol, 21-deoxycortisol) the proposed enzyme inhibition, on end products of steroid biosynthesis (cortisol and aldosterone) and on endogenous adrenocorticotrophic hormone (ACTH) concentrations in dogs with PDH. Hormones of the steroid biosynthesis pathway were evaluated in 15 dogs before and 1h after injection of synthetic ACTH prior to (t(0)), in weeks 1-2 (t(1)) and in weeks 3-7 (t(2)) of trilostane treatment. Endogenous ACTH concentrations were measured at the same time points before performing the ACTH stimulation test. During trilostane treatment baseline and post-stimulation cortisol concentrations decreased significantly. Baseline serum aldosterone levels showed a significant increase; post-stimulation values decreased. Baseline and post-stimulation 17alpha-OH-pregnenolone and dehydroepiandrostenedione concentrations increased significantly. 17alpha-OH-progesterone and androstenedione levels did not change. Post-stimulation 21-deoxycortisol concentrations decreased significantly, baseline 11-deoxycortisol concentrations increased significantly. Endogenous ACTH levels showed a significant increase. The significant increase in 17alpha-OH-pregnenolone and dehydroepiandrostenedione concentrations confirms an inhibitory effect of trilostane on the 3beta-HSD. Since 17alpha-OH-progesterone concentrations did not change, but cortisol concentrations markedly decreased, trilostane seems to influence additional enzymes of the hormone cascade, like the 11beta-hydroxylase and possibly the 11beta-hydroxysteroid dehydrogenase.

Analysis of anabolic steroids by partial filling micellar electrokinetic capillary chromatography and electrospray mass spectrometry

A partial filling micellar electrokinetic capillary chromatography (PF-MEKC) separation of six anabolic androgenic steroids (androstenedione, metandienone, fluoxymesterone, methyltestosterone, 17-epimetandienone and testosterone) is introduced. The method utilises a mixed micellar solution consisting of sodium dodecyl sulphate (SDS) and sodium taurocholate. The analytes are detected with a photodiode array detector at 247 nm wavelength. Methyltestosterone is used as internal standard. The detection limits were 39 microg/L for androstenedione, 40 microg/L for testosterone, 45 microg/L for fluoxymesterone, 45-90 microg/L for 17-epimetandienone, 59 microg/L for methyltestosterone and 90 microg/L for metandienone. Linear correlation between concentration (0.1-5.0 mg/L) and detector response was obtained with r2 of 0.994 for fluoxymesterone, 0.998 for 17-epimetandienone and 0.999 for androstenedione, metandienone and testosterone. In addition, ionisation of the investigated compounds in electrospray mass spectrometry (ESI-MS) was studied in positive ion mode. The most intense signal (100%) was the protonated molecular ion [M + H]+, except for 17-epimetandienone, which gave its strongest signal at m/z corresponding to [M - H2O + H]+. Finally, separation and identification of fluoxymesterone, androstenedione and testosterone by PF-MEKC-ESI-MS is described. This is the first use of PF-MEKC and PF-MEKC-ESI-MS assays for anabolic androgenic steroids.