A liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based assay to profile 20 plasma steroids in endocrine disorders

Pre-analytical stability and physiological fluctuations affect plasma steroid hormone outcomes: A real-world study

Since steroids are crucial for diagnosing endocrine disorders, the lack of research on factors that affect hormone levels makes interpreting the results difficult. Our study aims to assess the stability of the pre-analytical procedure and the impact of hormonal physiological fluctuations using real-world data. The datasets were created using 12,418 records from individuals whose steroid hormone measurements were taken in our laboratory between September 2019 and March 2024. 22 steroid hormones in plasma by a well-validated liquid chromatography tandem mass spectrometry method were measured. After normalization transformation, outlier removal, and z-score normalization, generalized additive models were constructed to evaluate preanalytic stability and age, sex, and sample time-dependent hormonal fluctuations. Most hormones exhibit significant variability with age, particularly steroid hormone precursors, sex hormones, and certain corticosteroids such as aldosterone. 18-hydroxycortisol, 18-oxocortisol. Sex hormones varied between males and females. Levels of certain hormones, including cortisol, cortisone, 11-deoxycortisol, 18-hydroxycortisol, 18-oxocortisol, corticosterone, aldosterone, estrone, testosterone, dihydrotestosterone, dehydroepiandrosterone sulfate, 11-ketotestosterone, and 11-hydroxytestosterone, fluctuated with sampling time. Moreover, levels of pregnenolone and progesterone decreased within 1 hour of sampling, with pregnenolone becoming unstable with storage time at 4 degrees after centrifugation, while other hormone levels remained relatively stable for a short period of time without or after centrifugation of the sample. This is the first instance real-world data has been used to assess the pre-analytic stability of plasma hormones and to evaluate the impact of physiological factors on steroid hormones.

Black ginseng: a novel medicine for treating heart failure

Introduction: Black ginseng (BG) was processed by "steaming and drying" (generally nine times) repeatedly to produce "rare saponins" and secondary ginsenosides. Both ginseng (GS) and red ginseng (RG) were commonly used in treating heart failure (HF), and the latter was confirmed to be more potent, implying the presence of rare ginsenosides that contribute positively to the treatment of heart failure. Previous research indicated that rare ginsenosides are more abundant in BG than in RG. Consequently, this study aims to investigate the effects of BG and its components on HF to elucidate the active substances and their underlying mechanisms in the treatment of HF. Methods: The effects of BG and its fractions (water-eluted fraction (WEF), total saponin fraction (TSF), and alcohol-eluted fraction (AEF)) on rats with isoproterenol (ISO)-induced HF were explored, and steroids belonging to the hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-gonadal (HPG) axes were determined quantitatively using the ultra-performance liquid chromatography-triple quadrupole tandem mass spectrometry (UPLC-QqQ-MS/MS) method. In addition, 16S rDNA sequencing was performed on the gut microbiota, followed by GC-MS analysis of short-chain fatty acids (SCFAs), and the biochemical indexes related to energy metabolism and the serum cyclic nucleotide system were also analyzed by ELISA. Results: Based on a thorough evaluation of energy metabolism and the endocrine system, it was observed that the effects of BG components on the hypothalamic-pituitary-thyroid (HPT) and HPA axes were more pronounced. Notably, the treatment efficacy of the low dose of the total saponin fraction (TSFL), water decoction (WD), and high dose of the polysaccharide fraction (PSFH) was superior based on pharmacodynamic indicators such as brain natriuretic peptide (BNP), creatine kinase (CK), and estradiol (E2)/T). Furthermore, the WD and BG components exhibited significant effects on androgens (T and androstenedione (A4)). The TSFL group exerts an anti-inflammatory effect by regulating Lactobacillus/Erysipelotrichales. The WD, PSFH, and TSFL may impact inflammatory cytokines through the gut microbiota (Lactobacillus/Erysipelotrichales) and their metabolites (acetate and butyrate), exerting an anti-inflammatory effect. Discussion: The BG and all its split components demonstrated varying levels of efficacy in alleviating HF, and TSF and PSF exhibited a significant protective effect on HF. The main active components in TSF were revealed to be ginsenosides Rk1, Rk3, 20-(S)-Rg3, and 20-(S)-Rh2 by the H9C2 cell experiment. The decoction of BG and its components exhibited a potent impact on androgen hormones, with an elevation trend. This phenomenon may be attributed to the activation of the eNOS-NO pathway through androgen regulation, thereby contributing to its anti-HF activities. The WD, PSFH, and TSFL may exert anti-inflammatory effects through the intestinal flora (Lactobacillaceae/Erysipelotrichaceae) and its metabolites (acetic acid and butyric acid), which affect the inflammatory factors. The different mechanisms of action of each component of HF also reflect the significance and necessity of the overall role of traditional Chinese medicine (TCM). Our research was the first to report that the E2/T is related to HF and can be used as an indicator to evaluate HF.

Identifying biomarkers of ginseng medicines with different natures on heart failure

ETHNOPHARMACOLOGICAL RELEVANCE

The nature of Chinese medicine is a unique index to measure its efficacy. Generally, treating the hot syndrome with cold nature medicine and vice versa. Ginseng medicines, a renowned Chinese medicine known for its qi tonifying action, encompasses various herbal materials such as ginseng, red ginseng, and black ginseng (GS, RG, and BG, respectively), ginseng leaves (GL), and American ginseng (AG), which exhibited different natures, thought contained similar ginsenosides. This traditional effect of GS and RG "reinvigorate the pulse for relieving qi depletion". It is closely linked to anti-heart failure (HF), HF is a clinical manifestation of deficiency of "heart-qi". However, the elucidation of the mechanism underlying the anti-HF effects of ginseng medicines with different natures remains a significant challenge.

AIM OF THE STUDY

To elucidate pharmacological mechanisms underlying the effect of ginseng medicines on HF, and to identify biomarkers associated with their various natures. Furthermore, it provides the basis for the different applications of ginseng medicines with various natures.

MATERIALS AND METHODS

This study established a rat model of HF induced by isoproterenol (ISO) combined with a specific diet. Four representative hot/cold herbs were selected as compared references for the medicine natures. The divergent effects of these herbs on the HF model were investigated by analyzing RNA-seq data to identify genes expressed differentially. Additionally, pathways associated with medicine natures were obtained using KEGG. Furthermore, UPLC-QqQ-MS/MS, as well as ELISA, were used to measure indexes associated with the nervous system, energy metabolisms, and endocrinology systems, such as BNP, CK, IL-1, T3, T4, cAMP, cGMP, AD, adrenal hormones (DOC, CORT, and COR), progestogens (pregnenolone, P, 17-OH-PR, and 17-OH-P), androgens (DHEA, A4, and T), and estrogens hormones (E2).

RESULTS

All ginseng medicines demonstrated varying levels of efficacy in alleviating HF and GS exhibited a significant protective effect on HF. The ginseng medicines with qi tonifying primarily achieve their effect by enhancing the levels of adrenal hormones (DOC, CORT, and COR), T4, elevation of cAMP/cGMP, and activation of AchE. Warm nature qi tonifying ginseng medicines increased the levels of 17-OH-PR and P while decreasing 17-OH-P and the ratio of E2/T. On the other hand, cold nature qi tonifying ginseng medicines decreased the levels of A4 and T while increasing the ratio of E2/T.

CONCLUSION

Overall, the effects of warm nature ginseng medicines are stronger on HF compared to cold nature ginseng medicines. Our research firstly reported that the E2/T ratio, progestogens (17-OH-PR, 17-OH-P, and P), and androgens (A4 and T) have been identified as significant biomarkers for discerning the mechanism differences of ginseng medicines with differences natures in treatment of HF.

Plasma Steroid Profiling Combined With Machine Learning for the Differential Diagnosis in Mild Autonomous Cortisol Secretion From Nonfunctioning Adenoma in Patients With Adrenal Incidentalomas

OBJECTIVE

To assess the diagnostic value of combining plasma steroid profiling with machine learning (ML) in differentiating between mild autonomous cortisol secretion (MACS) and nonfunctioning adenoma (NFA) in patients with adrenal incidentalomas.

METHODS

The plasma steroid profiles data in the laboratory information system were screened from January 2021 to December 2023. EXtreme Gradient Boosting was applied to establish diagnostic models using plasma 24-steroid panels and/or clinical characteristics of the subjects. The SHapley Additive exPlanation (SHAP) method was used for explaining the model.

RESULTS

Seventy-six patients with MACS and 86 patients with NFA were included in the development and internal validation cohort while the external validation cohort consisted of 27 MACS and 21 NFA cases. Among 5 ML models evaluated, eXtreme Gradient Boosting demonstrated superior performance with an area under the curve of 0.77 using 24 steroid hormones. The SHAP method identified 5 steroids that exhibited optimal performance in distinguishing MACS from NFA, namely dehydroepiandrosterone, 11-deoxycortisol, 11β-hydroxytestosterone, testosterone, and dehydroepiandrosteronesulfate. Upon incorporating clinical features into the model, the area under the curve increased to 0.88, with a sensitivity of 0.77 and specificity of 0.82. Furthermore, the results obtained through SHAP revealed that lower levels of testosterone, dehydroepiandrosterone, low-density lipoprotein cholesterol, body mass index, and adrenocorticotropic hormone along with higher level of 11-deoxycortisol significantly contributed to the identification of MACS in the model.

CONCLUSIONS

We have elucidated the utilization of ML-based steroid profiling to discriminate between MACS and NFA in patients with adrenal incidentalomas. This approach holds promise for distinguishing these 2 entities through a single blood collection.

Development and validation of a versatile non-invasive urinary steroidomics method for wildlife biomonitoring

Wildlife conservation is often challenged by a lack of knowledge about the reproduction biology and adaptability of endangered species. Although monitoring steroids and related molecules can increase this knowledge, the applicability of current techniques (e.g. immunoassays) is hampered by species-specific steroid metabolism and the requisite to avoid invasive sampling. This study presents a validated steroidomics method for the (un)targeted screening of a wide range of sex and stress steroids and related molecules in urine using ultra-high performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS). In total, 50 steroids (conjugated and non-conjugated androgens, estrogens, progestogens and glucocorticoids) and 6 prostaglandins could be uniquely detected. A total of 45 out of 56 compounds demonstrated a detection limit below 0.01 ng μL-1. Excellent linearity (R2 > 0.99), precision (CV < 20 %), and recovery (80-120 %) were observed for 46, 41, and 39 compounds, respectively. Untargeted screening of pooled giant panda and human samples yielded 9691 and 8366 features with CV < 30 %, from which 84.1 % and 83.0 %, respectively, also demonstrated excellent linearity (R2 > 0.90). The biological validity of the method was investigated on male and female giant panda urine (n = 20), as well as pooled human samples (n = 10). A total of 24 different steroids were detected with clear qualitative and quantitative differences between human and giant panda samples. Furthermore, expected differences were revealed between female giant panda samples from different reproductive phases. In contrast to traditional biomonitoring techniques, the developed steroidomics method was able to screen a wide range of compounds and provide information on the putative identities of metabolites potentially important for reproductive monitoring in giant pandas. These results illustrate the advancements steroidomics brings to the field of wildlife biomonitoring in the pursuit to better understand the biology of endangered species.

Increased intestinal bile acid absorption contributes to age-related cognitive impairment

Cognitive impairment in the elderly is associated with alterations in bile acid (BA) metabolism. In this study, we observe elevated levels of serum conjugated primary bile acids (CPBAs) and ammonia in elderly individuals, mild cognitive impairment, Alzheimer's disease, and aging rodents, with a more pronounced change in females. These changes are correlated with increased expression of the ileal apical sodium-bile acid transporter (ASBT), hippocampal synapse loss, and elevated brain CPBA and ammonia levels in rodents. In vitro experiments confirm that a CPBA, taurocholic acid, and ammonia induced synaptic loss. Manipulating intestinal BA transport using ASBT activators or inhibitors demonstrates the impact on brain CPBA and ammonia levels as well as cognitive decline in rodents. Additionally, administration of an intestinal BA sequestrant, cholestyramine, alleviates cognitive impairment, normalizing CPBAs and ammonia in aging mice. These findings highlight the potential of targeting intestinal BA absorption as a therapeutic strategy for age-related cognitive impairment.

Simultaneous Determination of Selected Steroids with Neuroactive Effects in Human Serum by Ultrahigh-Performance Liquid Chromatography-Tandem Mass Spectrometry

Neuroactive steroids are a group of steroid molecules that are involved in the regulation of functions of the nervous system. The nervous system is not only the site of their action, but their biosynthesis can also occur there. Neuroactive steroid levels depend not only on the physiological state of an individual (person's sex, age, diurnal variation, etc.), but they are also affected by various pathological processes in the nervous system (some neurological and psychiatric diseases or injuries), and new knowledge can be gained by monitoring these processes. The aim of our research was to develop and validate a comprehensive method for the simultaneous determination of selected steroids with neuroactive effects in human serum. The developed method enables high throughput and a sensitive quantitative analysis of nine neuroactive steroid substances (pregnenolone, progesterone, 5α-dihydroprogesterone, allopregnanolone, testosterone, 5α-dihydrotestosterone, androstenedione, dehydroepiandrosterone, and epiandrosterone) in 150 μL of human serum by ultrahigh-performance liquid chromatography with tandem mass spectrometry. The correlation coefficients above 0.999 indicated that the developed analytical procedure was linear in the range of 0.90 nmol/L to 28.46 μmol/L in human serum. The accuracy and precision of the method for all analytes ranged from 83 to 118% and from 0.9 to 14.1%, respectively. This described method could contribute to a deeper understanding of the pathophysiology of various diseases. Similarly, it can also be helpful in the search for new biomarkers and diagnostic options or therapeutic approaches.

Determination of urinary androgens in women with polycystic ovary syndrome using LC-QqQ/MS and the application of thin film solid-phase microextraction (TF-SPME)

Hyperandrogenism is one of the most pronounced symptoms of Polycystic Ovary Syndrome (PCOS) and seems to play a key role in the pathogenesis of this complex disorder. Nevertheless, there is still a lack of consistent results regarding common steroid predictors of PCOS. Therefore, a liquid chromatography tandem mass spectrometry (HPLC-QqQ/MS) method was developed and validated to determine the concentrations of four classic androgens: androstenedione (An-dione), testosterone (T), 5α-dihydrotestosterone (DHT) and androsterone (An) in urine samples obtained from women with PCOS and healthy controls. The limits of detection were between 0.04 and 0.09 ng/mL, while the limits of quantification ranged from 0.1 to 0.3 ng/mL respectively. As a pre-treatment procedure prior to analysis, hydrolysis using β-glucuronidase and thin film solid-phase microextraction (TF-SPME) was applied. The methodology was employed to perform targeted metabolomics of urinary steroids in women with PCOS and healthy controls. All measured androgens: An-dione (p < 0.0001), T (p = 0.0001), DHT (p < 0.0001) and An (p = 0.0002) showed significantly higher concentrations in the urine of women with PCOS. The largest difference in the mean concentration was found for DHT, which was 2.8 times higher in the PCOS group (13.9 ± 14.1 ng/mg creatinine) in comparison to healthy controls (4.9 ± 3.4 ng/mg creatinine). The results of receiver operating characteristic curve indicated that determination of the panel of three urinary androgens: T+DHT+An-dione with, under the study assumptions, was the best predictor of PCOS diagnosis (AUC of ROC curve = 0.91 (95 % CI: 0.8212-0.9905). The application of an LC-MS/MS-based analysis, together with highly sensitive extraction techniques like TF-SPME, is a suitable approach to perform fast assays and obtain reliable results - crucial in the search for valuable and significant steroids predictors of PCOS.

Evolution of LC-MS/MS in clinical laboratories

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) has attracted significant attention in clinical practice owing to its numerous advantages. However, the widespread adoption of this technique is hindered by certain limitations, such as inappropriate analyte selection, low levels of automation, and a lack of specific reference intervals and quality control programs. This review comprehensively summarizes the current challenges associated with LC-MS/MS and proposes potential resolutions. The principle of utility should guide the selection of biomarkers, prioritizing their practical value over sheer quantity. To achieve full-process automation, methodological innovation is crucial for developing high-throughput equipment. Establishing reference intervals for mass spectrometry-based assays across multiple centers and diverse populations is essential for accurate result interpretation. Additionally, the development of commercial quality control materials assumes pivotal importance in ensuring assay reliability and reproducibility. Harmonization and standardization efforts should focus on the development of reference methods and materials for the clinical use of LC-MS/MS. In the future, commercial assay kits and laboratory-developed tests (LDTs) are expected to coexist in clinical laboratories, each offering distinct advantages. The collaborative efforts of diverse professionals is vital for addressing the challenges associated with the clinical application of LC-MS/MS. The anticipated advancements include simplification, increased automation, intelligence, and the standardization of LC-MS/MS, ultimately facilitating its seamless integration into clinical routines for both technicians and clinicians.

A comprehensive LC-MS/MS method for the simultaneous measurement of 24 adrenal steroids: From research to clinical practice

Steroids are essential in the differential diagnosis of congenital adrenal hyperplasia (CAH) subtypes; however, they may confuse physicians with multifarious results. In this study, we established a liquid chromatography tandem mass spectrometry (LC-MS/MS) method for the simultaneous measurement of 24 steroids and developed a steroid metabolite pathway-based report to aid physicians in understanding these results. Solid-phase extraction was used to concentrate and purify target plasma steroids. The linearity, precision, recovery, and matrix effects were thoroughly evaluated. PowerBuilder was used to transfer the results from LC-MS/MS to the graphic report in a laboratory information management system (LIS) and was applied to different subtypes of CAH. Twenty-four steroids were separated and analyzed in one sample preparation and two injections using LC-MS/MS. The linearity of the steroids was excellent, with coefficients of linear regression greater than 0.99. The relative recovery ranged from 90.0 to 107.1 %, whereas the intra- and total coefficient variations were 1.6 ∼ 8.7 % and 2.0 ∼ 9.9 %, respectively. Matrix effects were compensated after internal standard correction. A graphic combination report mode was established and used to effectively identify CAH subtypes. In conclusion, a useful LC-MS/MS method and graphic combination report of 24 steroids based on their metabolite pathways were established.

Multiplexing Quadrupole and Ion Trap Operation Modes on a "Brick" Miniature Mass Spectrometer

Although a quadruple mass analyzer and an ion trap mass analyzer have complementary analytical features, they usually have different geometries, operational modes, and electronic control systems. As a continuous effort to extend its coverage, both quadrupole and ion trap operation modes were realized on a "brick" miniature mass spectrometer with a single mass analyzer. In the quadrupole operation mode, low-mass ions ranging from 31 to 502 Th can be analyzed. On the other hand, the ion trap mode can be utilized to cover ions with higher mass to charge ratios (up to 922 Th), as well as performing tandem mass spectrometry. To realize the multiplexing of both operation modes, a printed circuit board (PCB)-based multi-electrode quadrupole-ion trap mass analyzer was designed and integrated in the system. To cover both volatile and non-volatile molecules, two ionization sources were also implemented, including a nano electrospray ionization source and an in-vacuum plasma ionization source. Performances of the instrument operated in these two modes were characterized, such as mass resolution, sensitivity, and mass range. Results demonstrate that the combination of the quadrupole and ion trap operation modes can provide new capabilities when solving analytical problems.

Mass Spectrometry Analysis for Clinical Applications: A Review

Mass spectrometry (MS) has become an attractive analytical method in clinical analysis due to its comprehensive advantages of high sensitivity, high specificity and high throughput. Separation techniques coupled MS detection (e.g., LC-MS/MS) have shown unique advantages over immunoassay and have developed as golden criterion for many clinical applications. This review summarizes the characteristics and applications of MS, and emphasizes the high efficiency of MS in clinical research. In addition, this review also put forward further prospects for the future of mass spectrometry technology, including the introduction of miniature MS instruments, point-of-care detection and high-throughput analysis, to achieve better development of MS technology in various fields of clinical application. Moreover, as ambient ionization mass spectrometry (AIMS) requires little or no sample pretreatment and improves the flux of MS, this review also summarizes its potential applications in clinic.

Association between Serum Per- and Polyfluoroalkyl Substance Levels and Risk of Central and Peripheral Precocious Puberty in Girls

Concerns about the endocrine-disrupting effects of per- and polyfluoroalkyl substances (PFASs) have raised questions about their potential influence on precocious puberty in girls, which is an emerging concern in some populations. However, epidemiological evidence is lacking. In this study, 882 serum samples were collected from girls with central precocious puberty (CPP, n = 226), peripheral precocious puberty (PPP, n = 316), and healthy controls (n = 340) in 2021 in Shanghai, China. The serum levels of 25 legacy and emerging PFASs and 17 steroids were measured. Results showed that PFAS exposure was positively associated with estradiol levels. Eleven PFASs were significantly or marginally associated with the higher odds of the overall precocious puberty. Across subtypes, PFASs were more clearly associated with PPP, while the associations with CPP were consistent in direction but did not reach statistical significance. These findings were consistent with the assessment of PFAS mixtures using quantile-based g-computation (qgcomp) and Bayesian kernel machine regression, with perfluorobutane sulfonate and 6:2 polyfluorinated ether sulfonate showing the highest contribution to joint effects. Although changes in serum estradiol could arise from various factors, our results suggest that the PFAS exposure may contribute to the increase in estradiol secretion, thereby increasing the risk of precocious puberty, especially PPP. The potential effects of PFASs on precocious puberty warrant further investigation, given the associated complications of public health concern, including psychological distress and increased risk of multiple diseases.

A model combining testosterone, Androstenedione and free testosterone index improved the diagnostic efficiency of polycystic ovary syndrome

OBJECTIVE

Hyperandrogenism is frequently observed in patients with polycystic ovary (PCOS). The purpose of this study was to develop an easy-to-use tool for predicting polycystic ovary syndrome (PCOS) and to evaluate and compare the value of androstenedione (Andro) and other hormone indicators in the diagnosis of patients with hyperandrogenic PCOS.

METHODS

This study included 139 women diagnosed with hyperandrogenic PCOS according to the Rotterdam criteria and 74 healthy control women from Shanghai Tenth People's Hospital. The serum hormone levels of the patients and controls were measured using a chemiluminescence immunoassay (CLIA) and incorporated for further analysis.

RESULTS

Total testosterone (TT), Andro, Dehydroepiandrosterone sulfate (DHEAS), and Free androgen index (FAI) were significantly higher in the PCOS group than the control group. Further, Andro, FSH, LH, TT, FAI and LH/FSH in the hyper-androstenedione (HA) group were higher than the normal Andro (NA) group. The Youden index was the highest for Andro (0.65), with 81.82% sensitivity and 83.16% specificity. Correlation analysis showed that FSH, LH, TT, FAI, Insulin Sensitivity Index (ISI), and LH/FSH were positively correlated with Andro, while Fasting blood glucose (FPG) and two-hour postprandial blood glucose (2h PG) were negatively correlated with Andro.

CONCLUSIONS

The model using Andro, TT, FAI may help to identifying women with undiagnosed PCOS. Serum Andro is a meaningful biomarker for hyperandrogenism in PCOS patients and may further aid disease diagnosis.

Analysis of serum reproductive hormones and ovarian genes in pubertal female goats

BACKGROUND

Age at puberty is an important factor affecting goat fertility, with endocrine and genetic factors playing a crucial role in the onset of puberty. To better understand the relationship between endocrine and genetic factors and mechanisms underlying puberty onset in goats, reproductive hormone levels were analyzed by ELISA and ultraperformance liquid chromatography-multiple reaction monitoring-multistage/mass spectrometry and RNA sequencing was performed to analyze ovarian genes.

RESULTS

Serum follicle stimulating hormone, luteinizing hormone, estradiol, 11-deoxycortisol, 11-deoxycorticosterone, corticosterone, cortisone, and cortisol levels were found to be higher but progesterone were lower in pubertal goats as compared to those in prepubertal goats (P < 0.05). A total of 18,139 genes were identified in cDNA libraries, and 75 differentially expressed genes (DEGs) were identified (|log₂ fold change|≥ 1, P ≤ 0.05), of which 32 were significantly up- and 43 were down-regulated in pubertal goats. Gene ontology enrichment analyses indicated that DEGs were mainly involved in "metabolic process," "signaling," "reproduction," and "growth." Further, DEGs were significantly enriched in 91 Kyoto Encyclopedia of Genes and Genomes pathways, including estrogen signaling pathway, steroid hormone biosynthesis, and cAMP signaling pathway. Bioinformatics analysis showed that PRLR and THBS1 were highly expressed in pubertal ovaries, and ZP3, ZP4, and ASTL showed low expression, suggesting their involvement in follicular development and lutealization.

CONCLUSIONS

To summarize, serum hormone changes and ovarian DEGs expression were investigated in our study. Further studies are warranted to comprehensively explore the functions of DEGs in goat puberty.

Alteration of gut microbiome and metabolome by Clostridium butyricum can repair the intestinal dysbiosis caused by antibiotics in mice

This study evaluated the repair effects of Clostridium butyricum (CBX 2021) on the antibiotic (ABX)-induced intestinal dysbiosis in mice by the multi-omics method. Results showed that ABX eliminated more than 90% of cecal bacteria and also exerted adverse effects on the intestinal structure and overall health in mice after 10 days of the treatment. Of interest, supplementing CBX 2021 in the mice for the next 10 days colonized more butyrate-producing bacteria and accelerated butyrate production compared with the mice by natural recovery. The reconstruction of intestinal microbiota efficiently promoted the improvement of the damaged gut morphology and physical barrier in the mice. In addition, CBX 2021 significantly reduced the content of disease-related metabolites and meanwhile promoted carbohydrate digestion and absorption in mice followed the microbiome alternation. In conclusion, CBX 2021 can repair the intestinal ecology of mice damaged by the antibiotics through reconstructing gut microbiota and optimizing metabolic functions.

Melatonin in different food samples: Recent update on distribution, bioactivities, pretreatment and analysis techniques

Melatonin (MLT) plays a significant role on maintaining the basic physiological functions and regulating various metabolic processes in plentiful organisms. Recent years have witnessed an increase in MLT's share in global market with its affluent functions. However, the worrisome quality issues and inappropriate or excessive application of MLT take place inevitably. In addition, its photosensitive properties, oxidation, complex substrate concentration and trace levels leave exact detection of MLT doubly difficult. Therefore, it is essential to exploit precise, sensitive and stable extraction and detection methods to resolve above questions. In this study, we reviewed the distribution and bioactivities of MLT and conducted a comprehensive overview of the developments of pretreatment and analysis methods for MLT in food samples since 2010. Commonly used pretreatment methods for MLT include not only traditional techniques, but also novel ones, such as solid-phase extraction, QuEChERS, microextraction by packed sorbent, solid phase microextraction, liquid phase microextraction, and so on. Analysis methods include liquid chromatography coupled with different detectors, GC methods, capillary electrophoresis, sensors, and so on. The advantages and disadvantages of different techniques have been compared and the development tendency was prospected.

Rapid Derivatization of Phenolic and Oxime Hydroxyl with Isonicotinoyl Chloride under Aqueous Conditions and Its Application in LC-MS/MS Profiling Multiclass Steroids

Quantification of steroids possesses a crucial clinical value in early diagnosis and prognosis evaluation of various endocrine diseases. However, it is still challenging to realize feasible analysis of estrogens, androgens, progestogens, and corticoids within one single workflow. In this study, two derivatization reactions were newly designed for improvement: (1) acylation of phenolic hydroxyl on estrogens with isonicotinoyl chloride (INC) under the catalysis of 4-dimethylaminopyridine and (2) post-modification of oxime hydroxyl on hydroxylamine-pretreated ketosteroids with INC. Both reactions could conduct instantaneously at room temperature under aqueous conditions. Moreover, the resulting phenolic-INC and oxime-INC esters exhibited favorable MS responses. Through integrating these derivatization strategies with cold-induced phase separation technology, a feasible LC-MS/MS method was developed for simultaneous quantification of 15 multiclass steroids with proper sample consumption (50 μL serum), satisfying sensitivity (lower limit of quantitation at 0.01-5.00 ng/mL) and high throughput (40 min for sample-preparation). The practical applicability was tested by detecting 30 real samples from pregnant and non-pregnant women. The obtained results showed a good agreement with a previous validated methodology.

A novel fully-automated method to measure steroids in serum by liquid chromatography-tandem mass spectrometry

Background

Steroids play a key role in numerous physiological processes. Steroid determination is a useful tool to explore various endocrine diseases. Because of its specificity, mass spectrometry is considered to be a reference method for the determination of steroids in serum compared to radioimmunoassay. This technology could progress towards more automation for the optimal organization of clinical laboratories and ultimately for the benefit of patients.

Methods

A fully automated ultra-high-performance liquid chromatography-tandem mass spectrometry method was developed and fully validated to determine five steroids in serum. Sample preparation was based on protein precipitation with filtration followed by online solid phase extraction. Chromatographic separation was performed using a biphenyl stationary phase.

Results

The method was successfully validated according to European Medicine Agency guidelines. Coefficients of variation did not exceed, respectively, 8.4% and 8.1% for intra- and inter-assay precision. Method comparison with radioimmunoassay showed a proportional bias for all compounds, except for testosterone in men. Comparison with another LC-MS/MS method demonstrated acceptable concordance for all steroids, although a small bias was observed for androstenedione.

Conclusion

The novelty of this method is that it has been fully automated. Automation provides benefits in traceability and allows significant savings in cost and time.

Delivery prediction by quantitative analysis of four steroid metabolites with liquid chromatography tandem mass spectrometry in asymptomatic pregnant women

BACKGROUND

Prediction of delivery is important for assessing due dates, providing adequate prenatal care, and suggesting appropriate interventions in preterm and post-term pregnancies. Recent metabolomic findings suggested that the temporal abundance information of metabolome can be used to predict delivery timing with high accuracy in a cohort of healthy women. However, a targeted and quantitative assay is required to further validate the clinical performance and utility of this group of metabolomic candidates in delivery prediction with a larger and independent cohort.

METHOD

LC-MS/MS quantitative assays were applied to determine the plasma concentrations of four steroid metabolites, including oestriol-16-glucuronide (E3-16-Gluc), 17-alpha-hydroxyprogesterone (17-OHP), tetrahydrodeoxycorticosterone (THDOC), and androstane-3,17-diol (A-3,17-Diol) in asymptomatic women of singleton pregnancies (≥30^th gestational weeks). Subsequent statistical analysis was conducted to assess the performance of the above candidates in delivery prediction.

RESULT

Using LC-MS/MS, four steroids were separated and quantified in 5.5 min. The coefficients of variation (CVs) of the four analytes at the lower limit of quantification ranged from 7.9% to 14.6%, with the R² values greater than 0.990 in the calibration curves. Of the 585 recruited pregnant women who ended up with spontaneous delivery, 17.1% and 82.9% of the subjects delivered within and after 7 days since plasma collection, respectively. In the receiver operator curve analysis, the gestational age-adjusted area under the curve of the combined measurements of E3-16-Gluc and 17-OHP was 0.69 (95% CI: 0.60-0.76), with the sensitivity of 87.0% (95% CI: 78.8%-92.9%) and specificity of 60.2% (95% CI: 55.7%-64.6%). Moreover, the positive and the negative predictive values were 28.3%-34.0% and 93.1%-97.4% respectively for this combined panel.

CONCLUSION

We performed analytical and clinical validation of a quantitation LC-MS/MS panel for the four steroids in the plasma of pregnant women. The steroid metabolites panel of E3-16-Gluc and 17-OHP was potentially useful for predicting delivery within one week in asymptomatic women of singleton pregnancies. Key messagesA quantitative LC-MS/MS assay for determining the plasma levels of 17-OHP, THDOC, A-3,17-Diol and E3-16-Gluc was developed and validated, in order to evaluate their predictive performance in asymptomatic delivery of singleton pregnancy. The levels of E3-16-Gluc and 17-OHP were found to be significantly elevated at the time of sampling in women that delivered within one week and their combinational testing may be potentially useful in delivery prediction.

Steroid Hormone Profiling in Hyperandrogenism and Non-hyperandrogenism Women with Polycystic Ovary Syndrome

The purpose of this study is to explore the differences in the steroid metabolic network between hyperandrogenic and non-hyperandrogenic women with polycystic ovary syndrome (PCOS). A sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) was employed for the quantification of 36 kinds of serum steroids in 80 PCOS women during their follicular phase. Compared with those in non-hyperandrogenemia PCOS women (NA-PCOS), the levels of 17-hydroprogesterone (P = 0.009), androstenedione (P < 0.001), total testosterone (P < 0.001), dihydrotestosterone (P = 0.025), estrone (P = 0.007), and estradiol (P < 0.001) were increased in hyperandrogenemia PCOS (HA-PCOS) women. It was suggested that HA-PCOS may have increased activity of P450c17 (17-hydropregnenolone/pregnenolone, P = 0.008), 3βHSD2 (androstenedione/dehydroepiandrosterone, P = 0.004), and 17βHSD3 (testosterone/dehydroepiandrosterone, P = 0.01) and decreased activity of 5α reductase (dihydrotestosterone/testosterone, P = 0.008). Moreover, the ratio of luteinizing hormone (LH) to follicle stimulating hormone (FSH) was found to be related to these increased steroids and enzyme activities. In conclusion, the HA-PCOS and the NA-PCOS women showed different steroid profiles, and the different enzyme activities in steroidogenic pathway may be the main reason for the difference.

Establishing and Verifying a Robust Liquid Chromatography–Tandem Mass Spectrometry Method to Simultaneously Measure Seven Androgens Present in Plasma Samples

Objectives: To develop a robust liquid chromatography–tandem mass spectrometry (LC–MS/MS) method to simultaneously measure seven human plasma androgens, namely testosterone (T), dihydrotestosterone (DHT), androstenedione (A4), dehydroepiandrosterone sulfate (DHEAS), dehydroepiandrosterone (DHEA), 11-ketotestosterone (11-KetoT), and 11β-hydroxytestosterone (11β-OHT). Design and Methods: Plasma was extracted via a solid phase extraction method, and the analytical performance of the assay was validated according to the Clinical & Laboratory Standards Institute guidelines. Overall, 73 apparently healthy volunteers were recruited to evaluate the distribution of these seven androgens; their levels in 25 females with acne and 33 obese females were also evaluated. Results: The developed method exhibited a good precision, with the total coefficient variations (CV) and the intra-assay CVs being within 10%. Furthermore, the recoveries of T, DHT, A4, DHEA, DHEAS, 11-KetoT, and 11β-OHT were 90.3–105.8, 88.7–98.1, 92.4–102.5, 90.5–106.7, 87.6–99.9, 93.3–105.3, and 90.2–104.4%, respectively, and no significant matrix effect was observed after internal standard correction (<20%). Moreover, the limits of quantification were 0.01, 0.01, 0.01, 0.10, 5.00, 0.02, and 0.02 ng/mL for T, DHT, A4, DHEA, DHEAS, 11-KetoT, and 11β-OHT, respectively, which are adequate for their accurate measurement in human plasma samples. It was also determined that patients diagnosed with acne had significantly higher levels of DHT, A4, and DHEAS, while those suffering from obesity had significantly higher levels of T and A4 but lower levels of DHT. Conclusions: A robust LC-MS/MS method for the simultaneous determination of seven androgens in plasma samples was successfully established and validated, which plays important roles in clinical application.

Determination of steroid hormone residues in farmed fish using high-resolution orbital ion trap mass spectrometry

A method for the determination of 15 steroid hormones in farmed fish by liquid chromatography-orbital ion trap mass spectrometry has been developed and validated. The method involved sample preparation with acetonitrile extraction and clean-up, and separation in the LC using a C₁₈ column. The orbital ion trap MS was operated at a resolution of 35 000 FWHM in selected ion monitoring mode. An ion source with heated electrospray ionization was used in positive ionization mode. The samples were prepared by solid-phase extraction. The limit of quantification of steroid hormones in fish samples was 2 μg kg^-1. Good linearity was observed since correlation coefficients were more than 0.99 for all compounds. Recoveries of spiked fish samples (2 μg kg^-1 and 20 μg kg^-1) ranged from 80.8% to 112.6% with relative deviations less than 15%. The method was successfully applied to detect steroid hormones in real farmed fish samples at the μg kg^-1 level.

Diagnostic value of total testosterone and free androgen index measured by LC-MS/MS for PCOS and insulin resistance

BACKGROUND

The objective of the study was to explore the clinical significance of steroid hormones in the diagnosis of PCOS and PCOS-related insulin resistance through liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) and chemiluminescent immunoassay (CLIA).

METHODS

The study included 114 patients with PCOS and 100 controls. Steroid hormone levels in serum were measured using LC-MS/MS and CLIA. The Bland-Altman method was used to check the consistency between the two methods. The diagnostic value of the LC-MS/MS method for female hyperandrogenemia and PCOS was evaluated.

RESULTS

Women with PCOS were younger than controls on average (p < 0.001). PCOS patients had higher luteal hormone (LH, p < 0.001), insulin (p = 0.002), estradiol (E2, p < 0.001), total testosterone (TT, p < 0.001), free androgen index (FAI, p = 0.021), dehydroepiandrosterone sulfate (DHEA, p = 0.021), insulin resistance index (HOMA-IR) (p = 0.034), and fasting glucose (p = 0.017) levels than controls as measured by CLIA. The diagnostic value of TT was the best, and the area under the AUC curve was 0.766. Women with PCOS had higher androstenedione (A2, p < 0.001), FAI (p < 0.001), TT (p < 0.001), and 17-hydroxyprogesterone (17-OHP, p < 0.001) levels than controls as measured by LC-MS/MS. The ROC curve showed that the diagnostic efficacy of A2, TT, and 17-OHP was 0.830, 0.851, and 0.714, respectively. The consistency of TT detected by LC-MS/MS and CLIA was poor according to the Bland-Altman method. Detected TT by LC-MS/MS had the highest diagnostic efficiency for PCOS. The diagnostic power of the LC-MS/MS results for PCOS-related insulin resistance was analyzed. The results showed that the FAI had the highest diagnostic power, with an ROC curve of 0.798.

CONCLUSION

LC-MS/MS is more sensitive and accurate than CLIA in the determination of serum TT and FAI. TT is more effective for the diagnosis of PCOS, whereas FAI is more valuable in the diagnosis of insulin resistance.

A simple method for rapid screening and diagnosis of common organic acidemias: quantitative detection of serum and urine organic acid profiles based on liquid chromatography-tandem mass spectrometry

Organic acid (OA) analysis is a specific test for inherited metabolic disorders (IMDs); however, the previous detection methods are laborious and costly. This study aims to develop a rapid method for the simultaneous quantification of serum and urine OA profiles. The method was established based on the liquid chromatography-tandem mass spectrometry (LC-MS/MS) technique. The specificity, sensitivity, robustness, and accuracy of the established method were validated. Fifteen healthy subjects and nine IMD patients were measured for clinical validation. OAs with their intrinsic isomers were completely separated. The LC-MS/MS analysis time was 5.5 min. Calibration curves were linear within the ranges of 27.00 μg/g for all OAs. The average correlation relationship (R) varied from 0.9891 to 0.9998. The limit of detection and limit of quantification varied from 0.003 to 0.07 μg/g and 0.006 to 0.08 μg/g, respectively. No obvious carryover was observed. The intra-assay, inter-assay, and total imprecisions were 1.22-4.14%, 0.90-5.20%, and 1.67-5.90%, respectively. The mean spiked recovery at the three levels varied from 94.31 to 106.68%. The matrix effects can be compensated for by internal standard correction. Nine IMD patients were identified. A robust LC-MS/MS method for the rapid determination of serum and urine OA profiles without derivatization or liquid-liquid extraction was developed and validated. The analysis of five common OAs can be completed in short minutes. This innovative LC-MS/MS method for OA profiles may present its potential in future rapid screening and diagnosis of IMDs.

Identification of different proteins binding to Na, K-ATPase α1 in LPS-induced ARDS cell model by proteomic analysis

Background

Acute respiratory distress syndrome (ARDS) is characterized by refractory hypoxemia caused by accumulation of pulmonary fluid, which is related to inflammatory cell infiltration, impaired tight junction of pulmonary epithelium and impaired Na, K-ATPase function, especially Na, K-ATPase α1 subunit. Up until now, the pathogenic mechanism at the level of protein during lipopolysaccharide- (LPS-) induced ARDS remains unclear.

Methods

Using an unbiased, discovery and quantitative proteomic approach, we discovered the differentially expressed proteins binding to Na, K-ATPase α1 between LPS-A549 cells and Control-A549 cells. These Na, K-ATPase α1 interacting proteins were screened by co-immunoprecipitation (Co-IP) technology. Among them, some of the differentially expressed proteins with significant performance were identified and quantified by liquid chromatography-tandem mass spectrometry (LC–MS/MS). Data are available via ProteomeXchange with identifier PXD032209. The protein interaction network was constructed by the related Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Several differentially expressed proteins were validated by Western blot.

Results

Of identified 1598 proteins, 89 were differentially expressed proteins between LPS-A549 cells and Control-A549 cells. Intriguingly, protein–protein interaction network showed that there were 244 significantly enriched co-expression among 60 proteins in the group control-A549. while the group LPS-A549 showed 43 significant enriched interactions among 29 proteins. The related GO and KEGG analysis found evident phenomena of ubiquitination and deubiquitination, as well as the pathways related to autophagy. Among proteins with rich abundance, there were several intriguing ones, including the deubiquitinase (OTUB1), the tight junction protein zonula occludens-1 (ZO-1), the scaffold protein in CUL4B-RING ubiquitin ligase (CRL4B) complexes (CUL4B) and the autophagy-related protein sequestosome-1 (SQSTM1).

Conclusions

In conclusion, our proteomic approach revealed targets related to the occurrence and development of ARDS, being the first study to investigate significant differences in Na, K-ATPase α1 interacting proteins between LPS-induced ARDS cell model and control-A549 cell. These proteins may help the clinical diagnosis and facilitate the personalized treatment of ARDS.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12953-022-00193-3.

Mass spectrometry-based cortisol profiling during adrenal venous sampling reveals misdiagnosis for subtyping primary aldosteronism

OBJECTIVE

Primary aldosteronism (PA) is a common form of secondary hypertension. Adrenal venous sampling (AVS) is the gold standard for subtyping PA. This study aimed to determine whether there is a difference between immunoassays and liquid chromatography-mass spectrometry (LC-MS/MS) methods for measuring cortisol levels that affect the judgement of AVS.

DESIGN

This was a retrospective study.

PATIENTS

Included 72 patients who were diagnosed with PA and had undergone AVS.

MEASUREMENTS

Patients were grouped according to whether they received adrenocorticotropic hormone (ACTH) stimulation during AVS, and the cortisol results were measured using immunoassay and LC-MS/MS.

RESULTS

There were 48 patients in the without ACTH stimulation group and 24 in the post-ACTH stimulation group during AVS (bilateral adrenal vein cannulation success rate, 56.25% vs. 83.33%). ACTH stimulation was beneficial for increasing the success rate of AVS (p < .001). Immunoassays were linearly correlated with LC-MS/MS when cortisol concentrations were <1750 nmol/L (r = .959, p < .001). When cortisol concentrations were >17,500 nmol/L, no correlation was found between the two methods (p = .093). The two methods were consistent for the detection of cortisol for evaluating the success of cannulation for AVS. Five percent of patients showed discordant lateralization of aldosterone production according to the cortisol LC-MS/MS and immunoassay results in the without ACTH group, and 15% showed discordant lateralization in the post-ACTH group.

CONCLUSIONS

The immunoassay method can be used to determine whether cannulation is successful. The final decision for lateralization may be more appropriate based on LC-MS/MS results.

Follicular fluid steroid and gonadotropic hormone levels and mitochondrial function from exosomes predict embryonic development

PURPOSE

Human follicular fluid (FF) is a complex biological fluid that contributes to the micro-environment of oocyte development. The aim of this study was to evaluate the role of steroid and gonadotropic hormones levels and mitochondrial function in embryo development during in vitro fertilization cycles.

METHODS

This was a cohort study of 138 women receiving IVF/ICSI, including 136 FF samples from 109 infertile women. FF steroid and gonadotropic hormones levels were tested by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and immunoassays. The mRNA expression levels of mitochondrial electron transport chain (ETC) complex genes from FF exosomes were detected by qPCR.

RESULTS

Analysis of these individual FF concentrations revealed that LH and FSH concentrations were higher in follicles in which the oocyte developed into a top quality (TQ) blastocyst (LH: 9.44 ± 2.32mIU/ml, FSH: 9.32 ± 1.01mIU/ml) than those in which there was a failure of fertilization (LH: 5.30 ± 0.84mIU/ml, FSH: 6.91 ± 0.62mIU/ml). In contrast, follicular cortisone concentrations were lower for oocytes that resulted in a TQ blastocyst (12.20 ± 0.82mIU/ml). The receiver operating characteristic analysis showed that FF LH and FSH levels predicted TQ blastocyst with excellent AUC value of 0.711 and 0.747. Mitochondrial ETC complex I and III mRNA levels were increased in the FF exosomes of TQ blastocyst. Correlation analysis showed that mRNA levels of ETC complex I was positively correlated with LH and FSH levels in FF.

CONCLUSION

The levels of FF steroid and gonadotropic hormones from single follicle can predetermine subsequent embryo development to some extent. Furthermore, impaired exosome mitochondrial dysfunction is a potiential event that causes hormone change in embryo development.

Fast Screening and Identification of Illegal Adulterated Glucocorticoids in Dietary Supplements and Herbal Products Using UHPLC-QTOF-MS With All-Ion Fragmentation Acquisition Combined With Characteristic Fragment Ion List Classification

Ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) with all-ion fragmentation (AIF) acquisition was established for an identification and quantification of illegal adulterated glucocorticoids in dietary supplements and herbal products. Next, a novel method called characteristic fragment ion list classification (CFILC) was developed for a fast screening of adulterated compounds. CFILC could provide the characteristic ions comprehensively and completely through direct extract from the MS² library instead of finding them manually. This is time-saving and provides fast screening results with a high confidence level by filtering of a pre-calculated threshold of similarity scores for illegal adulterants that are not included in the library as well as for new emerging structural analogs. The obtained results demonstrated the great qualitative and quantitative strength of this approach, providing a promising and powerful method for a routine fast screening of illegal adulterated glucocorticoids.

A developed HPLC-MS/MS method to quantitate 5 steriod hormones in clinical human serum by using PBS as the surrogate matrix

Steroid hormones play an essential role in regulating physiological and reproductive development throughout the lifetime of an individual. One of the difficulties in determining endogenous substances is the lack of a blank matrix. Especially when the level of analytes is lower than the level in the so-called blank matrix. In the present study, an optimized HPLC-MS/MS method was developed and validated to quantify androstenedione (ASD), testosterone (Ts), dehydroepiandrosterone (DHEA), 5α-dihydrotestosterone (DHT), and progesterone (P) in serum samples from healthy people using PBS (pH = 7.4) as the blank surrogate matrix. Simultaneously, the method investigated the characteristics of NaCl, bull serum albumin, pure water as surrogate matrices for the analysis of steroid hormones. The data showed that the matrix effects of ASD, Ts, DHEA, DHT, and P in the same groups were not significantly different between PBS and twice charcoal-stripped serum (CS₂S) as a blank surrogate matrix. Furthermore, the LLOQ using PBS as the blank matrix was up to 0.005 ng/mL for ASD, Ts, and P and 0.05 ng/mL for DHEA and DHT. The reference ranges of concentration (C_PBS) of 5 steroid hormones were provided. Compared to the concentration with CS₂S (C_CSS) as the blank surrogate matrix, the relative biases (RBs) of Ts, DHT, P, and DHEA were finally stabilized at approximately -0.7%, -15%, -1.2%, and 9.2%, respectively. The results suggest that, in the cases of special required, the developed HPLC-MS/MS method can be used to determine the absolute concentration of 5 hormones in biological samples with PBS as the blank surrogate matrix.

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) based assay for the simultaneous quantification of 18-hydroxycorticosterone, 18-hydroxycortisol and 18-oxocortisol in human plasma

18-hydroxycorticosterone (18-OHB), 18-hydroxycortisol (18-OHF) and 18-oxocortisol (18-OXOF) are important biomarkers for the diagnosis of subtypes of primary aldosteronism. The detection of these three analytes by liquid chromatography-tandem mass spectrometry (LC-MS/MS) is free from structurally similar compounds. The aim of this study was to develop and validate a new LC-MS/MS assay for the simultaneous quantification of 18-OHB, 18-OHF and 18-OXOF in plasma and to establish a reference intervals for apparently healthy population. Plasma samples were prepared by solid phase extraction and separated in an ultra-high performance reversed phase column. MS detection was achieved using a triple quadrupole mass spectrometer in both positive and negative ionization modes. The developed assay was then validated against standard guidelines. We collected 691 plasma samples from apparently healthy individuals (M:398, F:293) to establish the reference intervals. The analytes were separated and quantified within 5 min. The newly developed method demonstrated linearity for the detected steroid concentration in range of 5 to 3000 pg/ml for 18-OXOF (r² = 0.999) and 20 to 3000 pg/ml for 18-OHB (r² = 0.997) and 18-OHF (r² = 0.997). The lower limit of quantification (LLOQ) was 2.5 pg/ml, 20 pg/ml and 20 pg/m for 18-OXOF, 18-OHB and 18-OHF respectively. Specificity, precision, accuracy and stability were tested, and met the requirements of the guidelines. 18-OHB was higher in females than in males, but 18-OHF were higher in males than females. The reference intervals of 18-OHB, 18-OHF and 18-OXOF for both genders together were 90.5-1040.6 pg/ml, 224.4-1685.2 pg/ml, 4.0-70.5 pg/ml, respectively. Age was also an important factor influencing the levels of these three hormones. We have developed a sensitive and reliable method for the simultaneous quantification of 18-OHB, 18-OHF, and 18-OXOF. Our work provides a reference interval for the clinical application of these three steroid hormones.

Correlation between steroid levels in follicular fluid and hormone synthesis related substances in its exosomes and embryo quality in patients with polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is an endocrine and metabolic disorder with various manifestations and complex etiology. Follicular fluid (FF) serves as the complex microenvironment for follicular development. However, the correlation between the concentration of steroid in FF and the pathogenesis of PCOS is still unclear.

METHODS

Twenty steroid levels in FF from ten patients with PCOS and ten women with male-factor infertility undergoing in vitro fertilization were tested by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in order to explore their possibly correlation with PCOS. Meanwhile, the mRNA levels of core enzymes in steroid synthesis pathway from exosomes of FF were also detected by qPCR.

RESULTS

The estriol (p < 0.01), estradiol (p < 0.05) and prenenolone (p < 0.01) levels in FF of PCOS group were significantly increased, compared to the normal group, and the progesterone levels (p < 0.05) were decreased in PCOS group. Increased mRNA levels of CYP11A, CYP19A and HSD17B2 of exosomes were accompanied by the hormonal changes in FF. Correlation analysis showed that mRNA levels of CYP11A and HSD17B2 were negatively correlated with percent of top-quality embryos and rate of embryos develop to blastocyst.

CONCLUSION

Our results suggest that increased levels of estrogen and pregnenolone in follicular fluid may affect follicle development in PCOS patients, and the mechanism is partially related to HSD17B1, CYP19A1 and CYP11A1 expression change in FF exosomes.

Analytical Methods for the Determination of Neuroactive Steroids

Neuroactive steroids are a family of all steroid-based compounds, of both natural and synthetic origin, which can affect the nervous system functions. Their biosynthesis occurs directly in the nervous system (so-called neurosteroids) or in peripheral endocrine tissues (hormonal steroids). Steroid hormone levels may fluctuate due to physiological changes during life and various pathological conditions affecting individuals. A deeper understanding of neuroactive steroids' production, in addition to reliable monitoring of their levels in various biological matrices, may be useful in the prevention, diagnosis, monitoring, and treatment of some neurodegenerative and psychiatric diseases. The aim of this review is to highlight the most relevant methods currently available for analysis of neuroactive steroids, with an emphasis on immunoanalytical methods and gas, or liquid chromatography combined with mass spectrometry.

From a single steroid to the steroidome: Trends and analytical challenges

For several decades now, the analysis of steroids has been a key tool in the diagnosis and monitoring of numerous endocrine pathologies. Thus, the available methods used to analyze steroids in biological samples have dramatically evolved over time following the rapid pace of technology and scientific knowledge. This review aims to synthetize the advances in steroids' analysis, from classical approaches considering only a few steroids or a limited number of steroid ratios, up to the new steroid profiling strategies (steroidomics) monitoring large sets of steroids in biological matrices. In this context, the use of liquid chromatography coupled to mass spectrometry has emerged as the technique of choice for the simultaneous determination of a high number of steroids, including phase II metabolites, due to its sensitivity and robustness. However, the large dynamic range to be covered, the low natural abundance of some key steroids, the selectivity of the analytical methods, the extraction protocols, and the steroid ionization remain some of the current challenges in steroid analysis. This review provides an overview of the different analytical workflows available depending on the number of steroids under study. Special emphasis is given to sample treatment, acquisition strategy, data processing, steroid identification and quantification using LC-MS approaches. This work also outlines how the availability of steroid standards, the need for complementary analytical strategies and the improvement of calibration approaches are crucial for achieving complete steroidome quantification.

Differential expression of peptides serves as an indicator of IgA nephropathy in pediatric patients

Peptide profiles change significantly with aging and peptide biomarkers discovered in adult patients may not be suitable for the evaluation of pediatric patients. The present study was designed to explore alterations in the serum peptidome profile of pediatric patients with IgA nephropathy (IgAN). A total of 17 children diagnosed with IgAN were recruited as the experimental group, 11 sex-matched healthy children were recruited as a healthy control group and 18 sex-matched children with other glomerular diseases were recruited as a disease control group. Serum peptides of each subject were enriched and analyzed by liquid chromatography with tandem mass spectrometry and the subsequently identified IgAN-specific peptides were evaluated using Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway analysis. Subsequently, the function of the IgAN-specific peptides was predicted via sequence comparison with other known functional bioactive peptides. A total of 123 peptides with a fold change >2 (P<0.05) and 48 peptides with a fold change >5 (P<0.05) were identified to be differentially expressed between the pediatric IgAN group and the two other groups. Consequently, two putative peptides that may have bioactive effects in the pathogenesis of IgAN in pediatric patients were identified. The serum peptidome profile of pediatric patients with IgAN was significantly different from the disease control group and the healthy control group. These differentially expressed peptides may serve as biomarkers for the minimally invasive diagnosis of pediatric patients with IgAN. Additionally, the potential bioactive peptides specifically expressed in pediatric IgAN patients that were identified in this study may lay a foundation for exploring new therapies for IgAN, such as the creation of novel peptide drugs.

Simultaneous quantitation of four androgens and 17-hydroxyprogesterone in polycystic ovarian syndrome patients by LC-MS/MS

Background

Due to the low concentration of androgens in women and the limitation of immunoassays, it remains a challenge to accurately determine the levels of serum androgens in polycystic ovary syndrome (PCOS) patients for clinical laboratories. In this report, a liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) method was developed and validated for simultaneous quantitation of testosterone (T), androstenedione (A4), dehydroepiandrosterone sulfate (DHEAS), dihydrotestosterone (DHT), and 17‐hydroxyprogesterone (17‐OHP) that are associated with PCOS.

Methods

The serum samples were processed by protein precipitation and solid phase extraction before analysis with the in‐house developed LC‐MS/MS. The chromatographic separation was achieved with a C18 column, using a linear gradient elution with two mobile phases: 0.02% formic acid in water (phase A) and 0.1% formic acid in methanol (phase B). The separated analytes were detected by positive or negative electrospray ionization mode under multiple reaction monitoring (MRM).

Results

The assay for all the five analytes was linear, stable, with imprecision less than 9% and recoveries within ±10%. The lower limits of quantification were 0.05, 0.05, 5, 0.025, and 0.025 ng/mL for T, A4, DHEAS, DHT, and 17‐OHP, respectively. In the receiver operating characteristic curve (ROC) analyses with the PCOS (n = 63) and healthy (n = 161) subjects, the AUC of the four‐androgen combined was greater than that of any single androgen tested in PCOS diagnosis.

Conclusions

The LC‐MS/MS method for the four androgens and 17‐OHP showed good performance for clinical implementation. More importantly, simultaneous quantitation of the four androgens provided better diagnostic power for PCOS.