Preclinical challenges in steroid analysis of human samples

Changes in cortisol, cortisone and 11β-hydroxysteroid dehydrogenase type II activity in saliva during pregnancy and lactation in sows

The activity of the enzyme 11β-hydroxysteroid dehydrogenase type II (11β-HSD type II), which can be estimated by the combined measurement of cortisol and cortisone, is gaining importance as a marker for the assessment of stress in pigs. The aim of this study was to investigate the activity of this enzyme and the salivary concentrations of cortisol and cortisone in pigs during pregnancy, farrowing and lactation and to compare it with other stress-related biomarkers such as Chromogranin A (CgA), S100A12 and alpha-amylase. Salivary cortisone concentrations and 11β-HSD type II activity decreased after farrowing, while cortisol concentrations increased. Enzyme activity did not show significant correlations with any of the other stress-related biomarkers measured in this study. Overall, the results of this report indicate a different regulation of 11β-HSD type II activity and of cortisol and cortisone during pregnancy and lactation, which should be considered when evaluating these analytes in saliva during these periods.

Cortisone in saliva of pigs: validation of a new assay and changes after thermal stress

BACKGROUND

Cortisone is derived from cortisol through the action of the enzyme 11β-hydroxysteroid dehydrogenase type II, and it has gained importance in recent years as a biomarker of stress. This study aimed to develop and validate an assay for the measurement of cortisone in pig saliva and evaluate whether its concentration varies in stressful situations. For this purpose, a specific immunoassay was developed and validated analytically, and a study was performed to evaluate whether cortisone concentrations in saliva can vary under heat stress conditions.

RESULTS

The assay proved to be accurate, reliable, and sensitive for the measurement of cortisone in pig saliva. The limit of detection of the assay was set at 0.006 ng/ml, and the lower limit of quantification was 0.023 ng/ml. It also correlated significantly with the results obtained by LC‒MS/MS (P = 0.003; r = 0.64). In addition, the cortisone concentration in animals subjected to prolonged heat stress decreased significantly 15 days after treatment (P < 0.0001).

CONCLUSIONS

According to these results, cortisone measured by this assay could be used as a tool for the non-invasive evaluation of thermal stress in pig saliva.

Comparative analysis of salivary cortisol measurements using different assay methods in relation to serum-free cortisol measurement

Objectives

Salivary cortisol reflects the biologically active form of serum cortisol, offering a noninvasive evaluation method for the diurnal rhythm of the hypothalamic-pituitary-adrenal (HPA) axis. While liquid chromatography-tandem mass spectrometry (LC-MS/MS) is known for its specificity, immunoassays (IA) are commonly used because of their simplicity. This study aimed to assess the performance of salivary cortisol measurement using both IA and LC-MS/MS in comparison to serum-free cortisol measurement.

Methods

Assay results for 188 saliva and 94 serum samples from 47 participants were analyzed. Salivary samples collected at different time points were analyzed using IA and LC-MS/MS. Serum samples were analyzed for cortisol, cortisol-binding globulin, and free cortisol. The statistical analyses included correlations and method comparisons.

Results

The diurnal salivary cortisol profiles exhibited a comparable circadian rhythm pattern; however, the concentrations measured using IA were consistently higher than those measured using LC-MS/MS. The correlation analysis revealed robust associations among salivary cortisol (IA), salivary cortisol (LC-MS/MS), and serum-free cortisol levels (LC-MS/MS). However, the method comparison revealed a systematic bias between IA and LC-MS/MS in salivary cortisol measurement.

Conclusions

This study contributes to the ongoing debate on assay techniques by affirming the suitability of IA and LC-MS/MS for salivary cortisol measurement to assess dynamic changes in HPA axis activity. The identified systematic bias emphasizes the importance of selecting methods based on specific research or clinical requirements.

High throughput LC-MS/MS method for steroid hormone analysis in rat liver and plasma - unraveling methodological challenges

Comprehensive reference data for steroid hormones are lacking in rat models, particularly for early developmental stages and unconventional matrices as the liver. Therefore, we developed and validated an enzymatic, solid-phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to quantify a panel of 23 steroid hormones in liver and plasma from adult and neonatal rats. Our approach tackles methodological challenges, focusing on undesired byproducts associated with specific enzymatic treatment, and enables a thorough assessment of potential interferences in complex matrices by utilizing unstripped plasma and liver. We propose an optimized enzymatic hydrolysis protocol using a recombinant β-glucuronidase/sulfatase mix (BGS mix) to efficiently deconjugate steroid phase II conjugates. The streamlined sample preparation and high-throughput solid phase extraction in a 96-well plate significantly accelerate sample processing for complex matrices and alarge number of samples. We were able to achieve the necessary sensitivity for accurately measuring the target analytes, particularly estrogens, in small sample sizes of 5-20 mg of liver tissue and 100 μL of plasma. Through the analysis of liver and plasma samples from adult and neonatal rats, including both sexes, our study showed a novel set of steroid hormone reference intervals. This study provides a reliable diagnostic tool for the quantification of steroids in rat models and gives insight in liver and plasma-related steroid hormone dynamics at early developmental stages. In addition, the method covers several pathway intermediates and extend the list of steroid hormones to be investigated.

Age, weight and circulating concentrations of total testosterone are associated with the relative prostatic size in adult intact male dogs

Prostatic hyperplasia (PH) is an androgen-dependent condition associated with increased prostatic size that is common in intact dogs, and similar to the condition in men. In dogs, the increase in prostatic size is most prominent the first years, and after approximately four years (in beagles), a plateau is reached, and further growth is slower. Why the prostate continues to grow more in some individuals is not clear. Most testosterone in the circulation is bound to albumin or sex hormone binding globulin (SHBG) and only a minor part is unbound and biologically active. The binding to SHBG has higher affinity than that to albumin. In addition, SHBG has own biological functions, modifying testosterone action. The aim of the present study was to investigate if there is an association between relative prostatic size and the variables total testosterone concentration, SHBG concentration, an estimation of bioavailable testosterone: the ratio between testosterone and SHBG (free androgen index, FAI), estradiol concentration, the estradiol/testosterone ratio, dog age and dog weight. Hormone concentrations were measured in serum from 79 intact male dogs aged ≥ four years, weighing ≥ five kg. The size of the prostate was estimated using ultrasonography, and relative prostate size, S_rel, was calculated as the estimated size related to the normal size for a 4-year-old dog of the same weight. There as a negative correlation between testosterone concentration and age (ρ = -0.27, P = 0.018) and a positive correlation between age and S_rel (ρ = 0.27, P = 0.016) and between SHBG and weight (ρ = 0.38, P = 0.001). The FAI was negatively correlated with dog weight (ρ = -0.32, P = 0.004). There were no significant correlations between S_rel and SHBG or FAI or between estradiol or estradiol/testosterone and S_rel, age or weight. A multiple regression analysis showed significant associations between log S_rel and log testosterone concentration, log age and log weight of the dog, with an adjusted R² of 9.5%. Although the variables total testosterone concentration, age and weight of the dog were all significantly associated with S_rel, the coefficient of determination was low, indicating that they only explained a minor part of the prostatic size. The results support the analysis of total testosterone in studies of prostatic growth in the dog.

The adrenal steroid profile in adolescent depression: a valuable bio-readout?

There is preliminary evidence that adrenal steroids other than cortisol may be valuable biomarkers for major depressive disorder (MDD). So far, studies have been conducted in adults only, and conclusions are limited, mainly due to small sample sizes. Therefore, the present study assessed whether adrenal steroids serve as biomarkers for adolescent MDD. In 261 depressed adolescents (170 females) treated at a single psychiatric hospital, serum adrenal steroids (progesterone, 17-hydroxyprogesterone, 21-deoxycortisol, 11-deoxycortisol, cortisol, cortisone, deoxycorticosterone, corticosterone) were determined by liquid chromatography-tandem mass spectrometry. Findings were compared to that of an age- and sex-matched reference cohort (N = 255) by nonparametric analysis of variance. Nonparametric receiver operating characteristics (ROC) analyses were conducted to evaluate the diagnostic performance of single steroids and steroid ratios to classify depression status. Sensitivity analyses considered important confounders of adrenal functioning, and ROC results were verified by cross-validation. Compared to the reference cohort, levels of deoxycorticosterone and 21-deoxycortisol were decreased (P < 0.001). All other glucocorticoid- and mineralocorticoid-related steroids were increased (P < 0.001). The corticosterone to deoxycorticosterone ratio evidenced excellent classification characteristics, especially in females (AUC: 0.957; sensitivity: 0.902; specificity: 0.891). The adrenal steroid metabolome qualifies as a bio-readout reflecting adolescent MDD by a distinct steroid pattern that indicates dysfunction of the hypothalamus-pituitary-adrenal axis. Moreover, the corticosterone to deoxycorticosterone ratio may prospectively qualify to contribute to precision medicine in psychiatry by identifying those patients who might benefit from antiglucocorticoid treatment or those at risk for recurrence when adrenal dysfunction has not resolved.

The Saliva Cortisol and Amylase Levels Related with Stress Response Compared by Different Analytical Methods

Sampling of salivary cortisol and amylase is a non-invasive method and important for the evaluation of the hypothalamic-pituitary-adrenal axis function and stress levels. This study aimed to compare the values of the salivary cortisol and amylase levels which were measured by three different analytical methods to discuss the alterations of stress levels of samples. The saliva samples of young adults (n = 23) were collected between 08.00 and 09.00 a.m., noon at 12.00 (before exam) and between 14.00 and 15.00 p.m. (after unaware exam). The samples were measured within the first 48 h, and no freezing/thawing was done. Salivary cortisol and amylase levels of subjects were measured by three different analytical methods as ELISA, chemiluminescence and biosensor methods. Comparison of ELISA and biosensor methods in order to determine the salivary cortisol levels showed a good correlation y = 2.971 + 0.748x (R2 = 0.839). Salivary amylase concentrations were only detected by ELISA method. Biosensor can be offered as an alternative analytic method to the conventional determination method ELISA. It can be preferred because of the detection/information effectiveness, low cost, fast results and specificity characteristics.

Liquid chromatography-tandem mass spectrometry measurement of 26 steroid hormones in human serum and plasma samples

The measurement of steroid hormones provided critical information in the clinical evaluation of endocrine disorders. In this study, we developed a high-throughput solid-phase extraction method for the analysis of 26 steroids in human serum and plasma samples by liquid chromatography-tandem mass spectrometry. Chromatographic conditions and sample preparation were optimized to achieve good separation and maximum sensitivity for these analytes. Under the optimum conditions, good linearities were achieved in the quantitative range for each steroid hormone with the correlation coefficients (r) larger than 0.99. The limits of quantitation of the method were in the range from 0.0005 to 0.7901 ng/mL. The recoveries were in the range of 87.2-114.2% with intra- and interday precision lower than 9.94%. This method has already been applied to series of samples from clinical trials, and there was no significant difference between serum and ethylenediaminetetraacetic acid plasma samples.

Salivary cortisol in healthy dogs: a randomized cross-over study to evaluate different saliva stimulation methods and their effects on saliva volume and cortisol concentration

BACKGROUND

Salivary cortisol collected at home is a useful test to diagnose and monitor Cushing's syndrome in humans. The main problem in dogs is to retrieve a sufficient amount of saliva. The aim of this study was to evaluate different salivary collection methods and compare their effects on volume, pH and cortisol concentration of saliva. Sixteen healthy Beagles were used in a 4 × 4 randomized crossover study with a washout period of 1 week between each of the following collection methods: 1. Salimetrics® cotton swab dipped in ginger powder (ginger group); 2. beef-flavored Salimetrics® (bouillon group); 3. Salivette® cotton swab with an enclosed treat (treat group); 4. plain Salimetrics® (control group). First, baseline saliva (plain cotton swab, S0) and, 2 min later, experimental saliva (according to group allocation above, SExp) were collected. Saliva was gathered by holding the swabs in the animal's mouth for 2 min. After the cross-over study, another saliva sample was collected from all dogs by the ginger method, using a 30 s sampling time (30s-ginger method). Cortisol concentrations were measured by liquid chromatography tandem mass spectrometry.

RESULTS

All three stimulation methods increased saliva production significantly (S0 compared to SExp: ginger p = 0.0005; bouillon p = 0.009; treat p = 0.007). Only ginger stimulation, however, generated a significantly higher amount of saliva (SExp) compared to the control group (p = 0.00001; median (range) amount of saliva for SExp: ginger 1200 ul (600-1700), bouillon 650 ul (200-1900), treat 700 ul (300-1000), control 400 ul (0-1100)). The amount of saliva retrieved by the 30s-ginger method was still higher than that from the control group (p = 0.0004). Bouillon and treat stimulation led to decreased pH values (bouillon, p = 0.0028; treat, 0.0018). Excitement was higher in the ginger group (p = 0.01). Chewing was intensified in the ginger and treat group (ginger, p = 0.003; treat, 0.0009). The cortisol concentration SExp was higher compared to that of S0 in the ginger and treat group (p = 0.02, 0.003). The experimental cortisol concentrations (SExp) were not different between groups.

CONCLUSIONS

The 30s-ginger method could prove useful in evaluating or monitoring dogs with Cushing's syndrome, as sampling at home for 30 s by the owner seems feasible.

11-Oxygenated Androgens Useful in the Setting of Discrepant Conventional Biomarkers in 21-Hydroxylase Deficiency

Context

Serum 17-hydroxyprogesterone (17OHP) and androstenedione (A4) are the conventional biomarkers used to assess disease control in patients with 21-hydroxylase deficiency (21OHD). However, discrepancy between the two is not uncommon, limiting interpretation.

Objective

To evaluate 11-oxyandrogens in discriminating good versus poor disease control in 21OHD in the setting of discrepant 17OHP and A4.

Methods

Retrospective analysis of 2738 laboratory assessments obtained as part of Natural History Study of congenital adrenal hyperplasia (CAH) at the National Institutes Health Clinical Center. Patients with discrepant 17OHP and A4 and available sera were selected. A 15-steroid mass-spectrometry panel was performed in sera from patients with 21OHD and age- and sex-matched controls. Patients were categorized in "good" or "poor" control based on clinical assessment (bone age advancement, signs and symptoms of precocious puberty, menstrual irregularity, hirsutism, or hypogonadotrophic hypogonadism).

Results

Discrepant 17OHP and A4 was found in 469 (17%) laboratory assessments. Of these, 403 (86%) had elevated 17OHP with A4 in reference range. Of 46 patients with available sera, 30 (65%) were in good control. Median fold elevation relative to controls was higher in patients with poor versus good control for 11-hydroxytestosterone (median [interquartile range], 2.82 [1.25-5.43] vs 0.91 [0.49- 2.07], P = .003), and 11-ketotestosterone (3.57 [2.11-7.41] vs 1.76 [1.24-4.00], P = .047). Fold elevation of 11-hydroxytestosterone between 3.48 (sensitivity 97%, specificity 47%) and 3.88 (sensitivity 100%, specificity 40%) provided the best discrimination between poor vs good control.

Conclusion

11-Oxyandrogens, especially 11-hydroxytestosterone, may be useful in the management of CAH when conventional biomarkers are inconclusive.

'When my autism broke': A qualitative study spotlighting autistic voices on menopause

LAY ABSTRACT

Autistic girls are known to struggle with the onset of menstruation, reporting that during their period, sensory sensitivities are heightened, it becomes more difficult to think clearly and control their emotions and they struggle more with everyday life and self-care. Yet surprisingly, nothing is known about how autistic women handle the menopausal transition in midlife. In non-autistic women, the menopause brings many physical changes and challenging symptoms from hot flushes to feeling more anxious and depressed. Because autistic women are already vulnerable to suicide, poor physical and mental health, and because they may already struggle with planning, controlling their emotions and coping with change, the menopause may be an especially challenging time. Yet, not one single study exists on the menopause in autism, so we conducted an online discussion (focus group) with seven autistic women. They confirmed that very little is known about menopause in autistic people, very little support is available and that menopause might be especially difficult for autistic people. Autism-related difficulties (including sensory sensitivity, socializing with others and communicating needs) were reported to worsen during the menopause, often so dramatically that some participants suggested they found it impossible to continue to mask their struggles. Participants also reported having extreme meltdowns, experiencing anxiety and depression, and feeling suicidal. This study highlights how important it is that professionals pay attention to menopause in autism, and discusses future research directions.

Salivary cortisol measurement in horses: immunoassay or LC-MS/MS?

The aim of the present study was to measure salivary cortisol concentrations of horses before and after hypothalamic-pituitary-adrenal (HPA) axis stimulation by means of liquid chromatography-tandem-mass spectrometry (LC-MS/MS) and an immunoassay (cELISA) for method comparison. Nine clinically healthy horses participated in the study. An ACTH stimulation test was performed. Saliva samples were collected before (T0) and 60 (T60) min after intravenous injection of 1 μg/kg BW synthetic ACTH1-24. LC-MS/MS was assessed for the determination of equine salivary cortisol. The results of these measurements were then compared to the results obtained by a cELISA, which has previously been validated for use in horses. The Pearson correlation coefficient was calculated and showed no correlation at T0 (r = -0.2452; P = 0.5249) and significantly correlated results at T60 (r = 0.8334; P = 0.0053). Bland-Altman-Plots of T60 revealed that immunoassay measurements led to higher outcome values than LC-MS/MS. On average, immunoassay results were 2.3 times higher. Poor agreement between both methods at T0 is potentially a consequence of inaccuracy in the very low measuring range of the immunoassay, and to a smaller extent, structurally similar cross-reacting agents and matrix effects, which might bias the results. Overestimation of immunoassay results at T60 might be due to different standardization of both methods, non-avoidable matrix effects on the antigen-antibody interaction in the ELISA, and possibly cross-reactions of other steroids. While immunoassay measurements of equine salivary cortisol yielded higher but reasonably correlated results for elevated cortisol concentrations after stimulation of the HPA axis, LC-MS/MS provided more accurate results, particularly for baseline cortisol concentrations close to the limit of detection of the ELISA.

Reference intervals of nine steroid hormones over the life-span analyzed by LC-MS/MS: Effect of age, gender, puberty, and oral contraceptives

New reference intervals need to be established for a new analytical method with improved sensitivity and specificity. We aimed to establish the new reference intervals from infancy to senescence of nine steroid hormones (cortisol, cortisone, progesterone, 17-hydroxyprogesterone (17-OHP), androstenedione, testosterone, estradiol, DHEAS, and aldosterone) for LC-MS/MS method. Serum samples from 4678 reference individuals (age range: 0.3-79 years) were measured with LC-MS/MS. Samples were collected between 7 a.m. and 10 a.m. Exclusion criteria were concomitant endocrine diseases and body mass index ≥ 33. Generalized additive model for location, scale and shape, the nonparametric or robust method was applied. We established the reference intervals of the nine steroid hormones by sex, age, and pubertal stage. Below the age of one, we observed the surge of androgen and estrogen which implied mini-puberty. At the same period of life, aldosterone and cortisone levels were very high reflecting physiological hyperaldosteronism. An increase of steroid hormones during the pubertal development and slow decrease towards senescence after the peak at early adulthood were observed. Due to the increase of CBG synthesis, cortisol levels were increased under oral contraceptives (OC) significantly (p < 0.0001), while OC suppressed progesterone, 17-OHP, androstenedione, and estradiol (p < 0.0001). Our results will facilitate the interpretation of patient data in routine diagnostics with the use of LC-MS/MS method. Since LC-MS/MS methods have shown good comparability among the different laboratories, our reference intervals can be further adopted in other laboratories equipped with LC-MS/MS, once the validation with a small number of reference samples is performed.

Steroidomics for the Prevention, Assessment, and Management of Cancers: A Systematic Review and Functional Analysis

Steroidomics, an analytical technique for steroid biomarker mining, has received much attention in recent years. This systematic review and functional analysis, following the PRISMA statement, aims to provide a comprehensive review and an appraisal of the developments and fundamental issues in steroid high-throughput analysis, with a focus on cancer research. We also discuss potential pitfalls and proposed recommendations for steroidomics-based clinical research. Forty-five studies met our inclusion criteria, with a focus on 12 types of cancer. Most studies focused on cancer risk prediction, followed by diagnosis, prognosis, and therapy monitoring. Prostate cancer was the most frequently studied cancer. Estradiol, dehydroepiandrosterone, and cortisol were mostly reported and altered in at least four types of cancer. Estrogen and estrogen metabolites were highly reported to associate with women-related cancers. Pathway enrichment analysis revealed that steroidogenesis; androgen and estrogen metabolism; and androstenedione metabolism were significantly altered in cancers. Our findings indicated that estradiol, dehydroepiandrosterone, cortisol, and estrogen metabolites, among others, could be considered oncosteroids. Despite noble achievements, significant shortcomings among the investigated studies were small sample sizes, cross-sectional designs, potential confounding factors, and problematic statistical approaches. More efforts are required to establish standardized procedures regarding study design, analytical procedures, and statistical inference.

Recent Advances and Challenges in Steroid Metabolomics for Biomarker Discovery

BACKGROUND

Steroid hormones belong to a group of low-molecular weight compounds which are responsible for maintenance of various body functions, thus, their accurate assessment is crucial for evaluation of biosynthetic defects. The development of reliable methods allowing disease diagnosis is essential to improve early detection of various disorders connected with altered steroidogenesis. Currently, the field of metabolomics offers several improvements in terms of sensitivity and specificity of the diagnostic methods when opposed to classical diagnostic approaches. The combination of hyphenated techniques and pattern recognition methods allows to carry out a comprehensive assessment of the slightest alterations in steroid metabolic pathways and can be applied as a tool for biomarker discovery.

METHODS

We have performed an extensive literature search applying various bibliographic databases for peer-reviewed articles concentrating on the applications of hyphenated techniques and pattern recognition methods incorporated into the steroid metabolomic approach for biomarker discovery.

RESULTS

The review discusses strengths, challenges and recent developments in steroidbased metabolomics. We present methods of sample collection and preparation, methods of separation and detection of steroid hormones in biological material, data analysis, and interpretation as well as examples of applications of steroid metabolomics for biomarker discovery (cancer, mental and central nervous system disorders, endocrine diseases, monitoring of drug therapy and doping control).

CONCLUSION

Information presented in this review will be valuable to anyone interested in the application of metabolomics for biomarker discovery with a special emphasis on disorders of steroid hormone synthesis and metabolism.

High-sensitivity quantification of serum androstenedione, testosterone, dihydrotestosterone, estrone and estradiol by gas chromatography-tandem mass spectrometry with sex- and puberty-specific reference intervals

BACKGROUND

Androgen and estrogen determinations serve as important diagnostic markers in a variety of clinical conditions. However, one challenge is to enhance assay sensitivity for determination in the lowest range, such as in prepubertal children. We here present a recently developed gas chromatography-tandem mass spectrometry (GC-MS/MS) method for determination of androstenedione (A₄), dihydrotestosterone (DHT), testosterone (T), estrone (E₁), and estradiol (E₂) in children, which we have compared with the sensitive radioimmunoassays; E₂ extraction-RIA and T-RIA.

METHODS

Steroids were extracted in ethyl acetate n-hexane solution from serum spiked with isotopically labeled internal standard and derivatized sequentially with pentafluorobenzyl bromide, pentafluorobenzyl hydroxylamine and pentafluoropropionic acid anhydride and analyzed by GC-MS/MS using a triple quadrupole mass spectrometer operated in negative chemical ionization mode. Leftover routine samples (n = 414) were used to evaluate the concordance between GC-MS/MS and RIAs and the validity of GC-MS/MS for pediatrics; of these samples, 101 were from seemingly healthy children. Pubertal stage was recorded for reference interval evaluation.

RESULTS

Lower limit of detection for A₄, T, DHT, E₁, and E₂ were 0.1 nmol/L, 0.1 nmol/L, 27 pmol/L, 9 pmol/L, and 2 pmol/L, respectively. Good agreement was found between GC-MS/MS and T-RIA (r = 0.98) as well as between GC-MS/MS and E₂ extraction-RIA (r = 0.98, for E₂ concentrations above 14 pmol/L). In boys, T and DHT increased significantly from prepuberty throughout pubertal development, and in girls the same increase was observed for E₁ and E₂. The greatest increase in A₄ for both genders, as well as E₁ and E₂ in boys and T and DHT in girls, occurred in mid to late puberty.

CONCLUSIONS

We report the development of a GC-MS/MS method sensitive enough to accurately determine serum levels of androgens and estrogens in children.

The evolution of methods for urinary steroid metabolomics in clinical investigations particularly in childhood

The metabolites of cortisol, and the intermediates in the pathways from cholesterol to cortisol and the adrenal sex steroids can be analysed in a single separation of steroids by gas chromatography (GC) coupled to MS to give a urinary steroid profile (USP). Steroids individually and in profile are now commonly measured in plasma by liquid chromatography (LC) coupled with MS/MS. The steroid conjugates in urine can be determined after hydrolysis and derivative formation and for the first time without hydrolysis using GC-MS, GC-MS/MS and liquid chromatography with mass spectrometry (LC-MS/MS). The evolution of the technology, practicalities and clinical applications are examined in this review. The patterns and quantities of steroids changes through childhood. Information can be obtained on production rates, from which children with steroid excess and deficiency states can be recognised when presenting with obesity, adrenarche, adrenal suppression, hypertension, adrenal tumours, intersex condition and early puberty, as examples. Genetic defects in steroid production and action can be detected by abnormalities from the GC-MS of steroids in urine. New mechanisms of steroid synthesis and metabolism have been recognised through steroid profiling. GC with tandem mass spectrometry (GC-MS/MS) has been used for the tentative identification of unknown steroids in urine from newborn infants with congenital adrenal hyperplasia. Suggestions are made as to areas for future research and for future applications of steroid profiling. As routine hospital laboratories become more familiar with the problems of chromatographic and MS analysis they can consider steroid profiling in their test repertoire although with LC-MS/MS of urinary steroids this is unlikely to become a routine test because of the availability, cost and purity of the internal standards and the complexity of data interpretation. Steroid profiling with quantitative analysis by mass spectrometry (MS) after chromatography now provides the most versatile of tests of adrenal function in childhood.

The dynamics of a serum steroid profile after stimulation with intravenous ACTH

BACKGROUND

Stimulation with intravenous adrenocorticotropic hormone (ACTH) is a widely used diagnostic procedure to characterize the adrenocortical function. Currently, the response of serum cortisol, mainly quantified by immunoassays, is the only established read-out of this test. By using liquid chromatography coupled with mass spectrometry (LC-MS/MS) simultaneous determination of several steroids that respond to ACTH stimulation is now possible. The aim of this study was to further characterize the typical effect of exogenous ACTH (250 mg) on a LC-MS/MS-serum steroid profile.

METHODS

A set of 36 paired samples (pre-/post-IV-ACTH) was investigated (age range 22-58, 26 female and 10 male individuals). Serum steroid profiling was performed using a LC-MS/MS method covering cortisol, cortisone, corticosterone, 11-deoxycortisol, 17-OH-progesterone and 11-deoxycorticosterone.

RESULTS

The concentrations of all measured steroids increased after stimulation with ACTH, except for cortisone. Serum corticosterone, 11-deoxycorticosterone and 11-deoxycortisol showed markedly more pronounced relative increases compared to cortisol. The strongest response was observed for corticosterone (15-fold median relative increase, compared to 1.4-fold median increase of cortisol).

CONCLUSION

Serum steroid profiling using LC-MS/MS after stimulation with IV ACTH demonstrates highly dynamic response patterns. Further studies should address in particular serum corticosterone as a potential novel marker of biochemical stress response.

Reference intervals for plasma concentrations of adrenal steroids measured by LC-MS/MS: Impact of gender, age, oral contraceptives, body mass index and blood pressure status

Background

Mass spectrometric-based measurements of the steroid metabolome have been introduced to diagnose disorders featuring abnormal steroidogenesis. Defined reference intervals are important for interpreting such data.

Methods

Liquid chromatography–tandem mass spectrometry was used to establish reference intervals for 16 steroids (pregnenolone, progesterone, 11-deoxycorticosterone, corticosterone, aldosterone, 18-oxocortisol, 18-hydroxycortisol, 17-hydroxyprogesterone, 21-deoxycortisol, 11-deoxycortisol, cortisol, cortisone, dehydroepiandrosterone, dehydroepiandrosterone-sulfate, androstenedione, testosterone) measured in plasma from 525 volunteers with (n = 227) and without (n = 298) hypertension, including 68 women on oral contraceptives.

Results

Women showed variable plasma concentrations of several steroids associated with menstrual cycle phase, menopause and oral contraceptive use. Progesterone was higher in females than males, but most other steroids were higher in males than females and almost all declined with advancing age. Using models that corrected for age and gender, body mass index showed weak negative relationships with corticosterone, 21-deoxycortisol, cortisol, cortisone, testosterone, progesterone, 17-hydroxyprogesterone and 11-deoxycorticosterone, but a positive relationship with 18-hydroxycortisol. Hypertensives and normotensives showed negligible differences in plasma concentrations of steroids.

Conclusion

Age and gender are the most important variables for plasma steroid reference intervals, which have been established here according to those variables for a panel of 16 steroids primarily useful for diagnosis and subtyping of patients with endocrine hypertension.

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Reference intervals established for LC-MS/MS-measurements of 16 plasma steroids

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Reference population consisted of 525 normotensive and hypertensive volunteers.

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Age and gender were the most important variables to consider for reference intervals.

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Weak negative associations of several steroids with body mass index

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Negligible associations of plasma steroids with blood pressure status

Steroid hormone analysis in diagnosis and treatment of DSD: position paper of EU COST Action BM 1303 'DSDnet'

Disorders or differences in sex development (DSD) comprise a heterogeneous group of conditions with an atypical sex development. For optimal diagnosis, highly specialised laboratory analyses are required across European countries. Working group 3 of EU COST (European Cooperation in Science and Technology) Action BM 1303 'DSDnet' 'Harmonisation of Laboratory Assessment' has developed recommendations on laboratory assessment for DSD regarding the use of technologies and analytes to be investigated. This position paper on steroid hormone analysis in diagnosis and treatment of DSD was compiled by a group of specialists in DSD and/or hormonal analysis, either from participating European countries or international partner countries. The topics discussed comprised analytical methods (immunoassay/mass spectrometry-based methods), matrices (urine/serum/saliva) and harmonisation of laboratory tests. The following positions were agreed upon: support of the appropriate use of immunoassay- and mass spectrometry-based methods for diagnosis and monitoring of DSD. Serum/plasma and urine are established matrices for analysis. Laboratories performing analyses for DSD need to operate within a quality framework and actively engage in harmonisation processes so that results and their interpretation are the same irrespective of the laboratory they are performed in. Participation in activities of peer comparison such as sample exchange or when available subscribing to a relevant external quality assurance program should be achieved. The ultimate aim of the guidelines is the implementation of clinical standards for diagnosis and appropriate treatment of DSD to achieve the best outcome for patients, no matter where patients are investigated or managed.

Immunoassay or LC-MS/MS for the measurement of salivary cortisol in children?

BACKGROUND

Dysregulation of the adrenal cortex has been assessed with measurement of salivary cortisol. So far salivary cortisol is routinely measured with immunoassay (IA). However, liquid chromatography-tandem mass spectrometry (MS) is known to offer better specificity. We compared the concentrations of salivary cortisol measured by MS and IA at basal and stress induced conditions and evaluated reasons for the difference in method-dependent cortisol results.

METHODS

Saliva samples (n=2703) were collected from 169 children (age range: 8-14 years; 81 healthy children; 55 with internalizing and 33 with externalizing disorders) under circadian conditions and during the Trier Social Stress Test for Children (TSST-C). Biochemical analyses were performed with MS for cortisol and cortisone, IA (IBL, RE62011) for cortisol, and enzyme kinetic assay for α-amylase.

RESULTS

MS and IA showed mostly comparable results for circadian activity and TSST-C response with similar statistical power. However, IA measured cortisol concentrations about 2.39-fold higher than MS. We found that this difference in measured values between MS and IA was mainly due to different standardization of IA compared to MS. In addition, at cortisol IA concentration below 5 nmol/L, cross-reactivity with cortisone was found to contribute to the lower concordance between MS and IA.

CONCLUSIONS

Immunoassay and LC-MS/MS were largely comparable in the interpretation of salivary cortisol dynamics in stress research. But the IA method revealed a restricted accuracy in the measuring range below 5 nmol/L.

The hyporeactivity of salivary cortisol at stress test (TSST-C) in children with internalizing or externalizing disorders is contrastively associated with α-amylase

BACKGROUND

Stress biomarkers of the autonomic nervous system and hypothalamic-pituitary-adrenal axis (HPA-axis) can be measured via alpha-amylase (AA) and cortisol and cortisone in saliva. Objectives were to determine 1) the response patterns of cortisol, cortisone, and AA under both circadian conditions and the Trier Social Stress Test for Children (TSST-C), 2) which reactivity index is most suitable to differentiate internalizing or externalizing disorders from controls, and to explore 3) the interaction between AA and cortisol in the presence of internalizing or externalizing disorders.

METHODS

Saliva samples (n = 2893) from children with internalizing (n = 55) or externalizing disorders (n = 33) and healthy children (n = 81) were analyzed for cortisol, cortisone, and AA under circadian conditions and TSST-C.

RESULTS

Circadian rhythm of three biomarkers did not differ between diagnostic groups. Age and gender were significant predictors for cortisol and awakening time influenced all three biomarkers significantly. TSST-C responses appeared sequentially in the order of AA, cortisol, and cortisone. Trajectories of cortisol and cortisone responses, not in AA, were significantly lower in children with internalizing or externalizing disorders than in healthy children. Cortisol percentage increase appeared to be the most suitable reactivity index to detect the difference between the diagnostic groups. Internalizing disorders had a negative association between AA decrease and cortisol increase (β = -.199, p < .05, R(2) = .304). Externalizing disorders had a positive association between AA baseline and cortisol increase (β = .229, p < .05, R(2) = .304).

CONCLUSION

An altered HPA-axis response during stress might result from chronic allostatic load in internalizing disorders and underaroused stress response system in externalizing disorders.

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) for analysis of endogenous steroids in the luteal phase and early pregnancy in dogs: a pilot study

BACKGROUND

Blood samples from dogs are often limited in volume, only allowing few steroids to be quantified with immunoassays. In addition, immunoassays may be compromised by interferences such as anti-reagent antibodies. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) can be used for the simultaneous quantitation of several steroids. This has not been described in dogs before.

OBJECTIVES

The aims were to use LC-MS/MS to study steroid profiles in early pregnancy and luteal phase in dogs, and to determine if differences exist between pregnant (P) and nonpregnant (NP) dogs.

METHODS

Nine female dogs were included, 4 during a NP luteal phase, 4 during a P luteal phase, and one during one NP and one P luteal phase. Blood samples were collected around the time of the LH surge (Day 0) and on Day 26. Serum was analyzed for 5 classes of steroids, including glucocorticoids, androgens, estrogens, pregnanes, and progestins, using LC-MS/MS methods.

RESULTS

The concentration of progesterone was significantly higher on Day 26 in P than in NP bitches. Distribution of concentrations of glucocorticoids, androgens, estrogens, or pregnanes in P and NP dogs were not statistically different. The predominating glucocorticoid was cortisol, and dihydroepiandrosterone (DHEA) was the predominating androgen. Concentration of estrone was comparable to oestradiol, whereas concentrations of pregnenolone were higher than those of 17-OH pregnenolone.

CONCLUSIONS

Only concentration of progesterone differed between P and NP bitches, being significantly higher on Day 26 in P than in NP bitches. LC-MS/MS offers interesting possibilities for studies of canine reproductive endocrinology.

Evaluation of steroidomics by liquid chromatography hyphenated to mass spectrometry as a powerful analytical strategy for measuring human steroid perturbations

This review presents the evolution of steroid analytical techniques, including gas chromatography coupled to mass spectrometry (GC-MS), immunoassay (IA) and targeted liquid chromatography coupled to mass spectrometry (LC-MS), and it evaluates the potential of extended steroid profiles by a metabolomics-based approach, namely steroidomics. Steroids regulate essential biological functions including growth and reproduction, and perturbations of the steroid homeostasis can generate serious physiological issues; therefore, specific and sensitive methods have been developed to measure steroid concentrations. GC-MS measuring several steroids simultaneously was considered the first historical standard method for analysis. Steroids were then quantified by immunoassay, allowing a higher throughput; however, major drawbacks included the measurement of a single compound instead of a panel and cross-reactivity reactions. Targeted LC-MS methods with selected reaction monitoring (SRM) were then introduced for quantifying a small steroid subset without the problems of cross-reactivity. The next step was the integration of metabolomic approaches in the context of steroid analyses. As metabolomics tends to identify and quantify all the metabolites (i.e., the metabolome) in a specific system, appropriate strategies were proposed for discovering new biomarkers. Steroidomics, defined as the untargeted analysis of the steroid content in a sample, was implemented in several fields, including doping analysis, clinical studies, in vivo or in vitro toxicology assays, and more. This review discusses the current analytical methods for assessing steroid changes and compares them to steroidomics. Steroids, their pathways, their implications in diseases and the biological matrices in which they are analysed will first be described. Then, the different analytical strategies will be presented with a focus on their ability to obtain relevant information on the steroid pattern. The future technical requirements for improving steroid analysis will also be presented.

An LC-MS/MS method for steroid profiling during adrenal venous sampling for investigation of primary aldosteronism

BACKGROUND

Steroid profiling for diagnosis of endocrine disorders featuring disordered production of steroid hormones is now possible from advances in liquid chromatography with tandem mass spectrometry (LC-MS/MS). Adrenal venous (AV) measurements of aldosterone and cortisol are a standard practice in the clinical work-up of primary aldosteronism, but do not yet take advantage of steroid profiling.

METHODS

A novel LC-MS/MS based method was developed for simultaneous measurement of 15 adrenal steroids: aldosterone, corticosterone, 11-deoxycorticosterone, progesterone, pregnenolone, cortisone, cortisol, 11-deoxycortisol, 17-hydroxyprogesterone, androstenedione, dehydroepiandrosterone, dehydroepiandrosterone-sulfate, 21-deoxycortisol, 18-oxocortisol and 18-hydroxycortisol. These were compared in peripheral venous (pV) and AV plasma from 70 patients undergoing AV sampling with and without cosyntropin stimulation. Aldosterone and cortisol levels measured by LC-MS/MS were compared with those measured by immunoassay.

RESULTS

Reproducibility of measurements with coefficients of variation ≤10% as well as analytical sensitivity sufficient to measure low pV levels particularly of aldosterone demonstrate the utility of the assay for profiling adrenal steroids in primary aldosteronism. Method comparisons indicated assay and concentration dependent differences of cortisol and aldosterone concentrations measured by immunoassay and LC-MS/MS. Median AV/pV ratios of 11-deoxycortisol (53.0), 17-hydroxyprogesterone (33.4), pregnenolone (62.4), androstenedione (40.6) and dehydroepiandrosterone (33.3) were 2.9- to, 5.4-fold larger than those for cortisol (11.6), with additionally generally larger increases than for cortisol with than without cosyntropin stimulation.

CONCLUSION

Our LC-MS/MS assay, in addition to improvements over existing immunoassay measurements of aldosterone and cortisol, offers profiling of 13 other adrenal steroids, providing a potentially useful method for the clinical work-up of patients with primary aldosteronism. In particular, the larger AV/pV ratios of several steroids compared to cortisol suggest more sensitive alternatives to the latter for assessing positioning of AV sampling catheters.

The use of mass spectrometry to improve the diagnosis and the management of the HPA axis

Liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) is becoming a standard analytical tool in the clinical laboratory for the measurement of small molecules, including steroid hormones. Endocrinologists are coming to acknowledge the superior quality of measurement that is achievable by LC-MS/MS through the enhanced analytical specificity and high sensitivity that this technique offers over conventional immunoassay (IA) methodologies. Additionally, LC-MS/MS overcomes many of the problems encountered in immunoassays, such as anti-reagent antibody interferences and cross-reactivity with structurally related compounds. The potential benefits of applying LC-MS/MS for the assessment of the hypothalamic-pituitary-adrenal (HPA) axis are beginning to be realised. This review critically evaluates recent developments in the application of LC-MS/MS for measurement of glucocorticoids and mineralocorticoids towards the diagnosis and management of HPA axis disorders and aims to address the current unmet need in this expanding field of endocrinology for which future studies into the potential applications of LC-MS/MS should be directed.

Standardized LC-MS/MS based steroid hormone profile-analysis

In order to overcome many limitations of immunoassays, high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) has the potential to find its place in the clinical laboratory medicine for quantification of steroid hormones. A prerequisite for the application of a new analytical procedure in clinical diagnostics is standardization to minimize analytical intra- and interlaboratory variability and inaccuracy. We evaluate a newly standardized HPLC-MS/MS assay in kit-format, developed for routine determination of 16 steroid hormones in human serum samples. Fifteen metabolites can be measured quantitatively, which include aldosterone, androstenedione, androsterone, corticosterone, cortisol, cortisone, 11-deoxycortisol, dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEAS), 17β-estradiol (E2), estrone (E1), etiocholanolone, 17α-hydroxyprogesterone (17OHP), progesterone, and testosterone. 11-Deoxycorticosterone is the only compound rated as semi-quantitative in this kit. The sample preparation is performed by solid phase extraction (SPE) on a 96-well plate. The standardized assay has been validated for human serum in terms of lower and upper limit of quantification (LLOQ 0.01-32 ng/mL, ULOQ 5-8000 ng/mL), linear correlation coefficient of calibration (R(2)>0.9966), intra- and inter-day precision (intra-day 1.1-8.8%, inter-day 5.2-14.8% and 8.2-18.6% for 11-deoxycorticosterone), accuracy (intra-day 88.3-115.5% and 109.3-128.2% for 11-deoxycorticosterone, inter-day 91.4-117.2% and 102.3-137.1% for 11-deoxycorticosterone), analytical total error (3.6-17.8%), proficiency test accuracy (85.4-113.4%), recovery (68-99%), and metabolite stability (freeze/thaw stability 95.5-108.1%, short term stability 86.9-107.2%). Inter-assay comparison with a routine reference HPLC-MS/MS assay and seven immunoassays demonstrates the outstanding high performance of this HPLC-MS/MS based kit by improvements in accuracy for progesterone, androstenedione, and 17OHP. Finally, results of two metyrapone tests demonstrate the potential of the standardized HPLC-MS/MS assay for the analysis of a comprehensive steroid hormone profile in clinical diagnostics.

Challenges and benefits of endogenous steroid analysis by LC–MS/MS

Quantification of endogenous hormonal steroids and their precursors is essential for diagnosing a wide range of endocrine disorders. Historically, these analyses have been carried out using immunoassay, but such methods are problematic, especially for low-concentration analytes, due to assay interference by other endogenous steroids. MS offers improved specificity over immunoassay and can be highly sensitive. GC–MS, with use of stable isotopically labeled internal standards, is considered the ‘gold standard’ method for serum steroid analysis. GC–MS is the method of choice for profiling steroid metabolites in urine, but these techniques are not appropriate for routine use in clinical laboratories owing to a need for extensive sample preparation, as well as analytical expertise. LC–MS/MS compares well to GC–MS in terms of accuracy, precision and sensitivity, but allows simplified sample preparation. While most publications have featured only one or a limited number of steroids, we consider that steroid paneling (which we propose as the preferred term for multitargeted steroid analysis) has great potential to enable clinicians to make a definitive diagnosis. It is adaptable for use in a number of matrices, including serum, saliva and dried blood spots. However, LC–MS/MS-based steroid analysis is not straightforward, and understanding the chemical and analytical processes involved is essential for implementation of a robust clinical service. This article discusses specific challenges in the measurement of endogenous steroids using LC–MS/MS, and provides examples of the benefits it offers.

Fast and sensitive liquid chromatography-mass spectrometry assay for seven androgenic and progestagenic steroids in human serum

A fast and sensitive LC-MS/MS method for the quantitative analysis of seven steroid hormones in 150 μl of human serum was developed and validated. The following compounds were included: 17α-hydroxypregnenolone, 17α-hydroxyprogesterone, androstenedione, dehydroepiandrosterone, testosterone, pregnenolone, and progesterone. Individual stable isotope-labeled analogues were used as internal standards. Sample preparation was performed by liquid-liquid extraction, followed by oxime derivatization to improve the ionization efficiency of the analytes. In contrast to the common derivatization-based methods, the reaction was incorporated into the sample preparation process and the only additional step due to the derivatization was a short heating of the autosampler vials before the sample injection. Chromatographic separation was achieved on a reversed-phase column using a methanol-water gradient. For the analyte detection, a triple quadrupole instrument with electrospray ionization was used. Total run time was 7.0 min and the lower limits of quantification were in the range of 0.03-0.34 nM (0.01-0.10 ng/ml), depending on the analyte. The method was validated using human serum samples from both sexes and applied for the serum steroid profiling of endometriosis patients.

Development and validation of a quantitative assay based on tandem mass spectrometry

Many routine hospital and clinical research assays have relied upon immunoassay procedures to achieve sensitive measurements of a range of important analytes. Some of the methods have been developed in-house but increasingly commercial kits and automated analysers have become commonplace. The accuracies of these methods are under question in health care. Mass spectrometry (MS) is potentially a more accurate technique with the ability to demonstrate specificity. An introduction of the basic analytical aspects of liquid chromatography (LC)–MS/MS leads on to the validation of the method before general use. LC coupled with MS and tandem mass spectrometry (MSn) is being adopted in a number of hospital laboratories for the quantitative analysis of a number of analytes from physiological matrices, but standards for development and validation of such assays are not easily available. Most assays can be regarded as in-house methods and herein may lay the failure so far for mass spectrometric methods to improve quality of results between laboratories for an analyte using the same technology. Manufacturers are taking on board the experience of clinical laboratories with kits containing all or most of the disposable items and reagents. A number of documents and guidelines have been consulted. These documents are expensive to purchase, are often very long and not easy to read. This review highlights the specific requirements for introduction of a tandem mass spectrometric test for small molecules into a routine hospital laboratory. A number of experiments need to be planned and executed in order to describe a new quantitative method in terms of selectivity, accuracy, imprecision, sensitivity and stability. The introduction of a quantitative method based on tandem MS requires careful validation. This review has distilled out important points from a number of key documents in order to provide a working validation guideline for clinical laboratories. In a supplementary file a working document for assembling the assay validation is proposed.