Simultaneous quantification of 17α-OH progesterone, 11-deoxycortisol, Δ4-androstenedione, cortisol and cortisone in newborn blood spots using liquid chromatography–tandem mass spectrometry

The use of liquid chromatography-tandem mass spectrometry in newborn screening for congenital adrenal hyperplasia: improvements and future perspectives

Newborn screening for congenital adrenal hyperplasia using 17-hydroxyprogesterone by immunoassay remains controversial despite screening been available for almost 40 years. Screening is confounded by poor immunoassay specificity, fetal adrenal physiology, stress, and illness which can result in a large number of false positive screening tests. Screening programmes apply higher screening thresholds based on co-variates such as birthweight or gestational age but the false positive rate using immunoassay remains high. Mass spectrometry was first applied to newborn screening for congenital adrenal hyperplasia over 15 years ago. Elevated 17-hydroxprogesterone by immunoassay can be retested with a specific liquid chromatography tandem mass spectrometry assay that may include additional steroid markers. Laboratories register with quality assurance programme providers to ensure accurate steroid measurements. This has led to improvements in screening but there are additional costs and added laboratory workload. The search for novel steroid markers may inform further improvements to screening. Studies have shown that 11-oxygenated androgens are elevated in untreated patients and that the adrenal steroidogenesis backdoor pathway is more active in babies with congenital adrenal hyperplasia. There is continual interest in 21-deoxycortisol, a specific marker of 21-hydroxylase deficiency. The measurement of androgenic steroids and their precursors by liquid chromatography tandem mass spectrometry in bloodspots may inform improvements for screening, diagnosis, and treatment monitoring. In this review, we describe how liquid chromatography tandem mass spectrometry has improved newborn screening for congenital adrenal hyperplasia and explore how future developments may inform further improvements to screening and diagnosis.

Steroid Profiling for the Diagnosis of Congenital Adrenal Hyperplasia by Microbore Ultra-performance Liquid Chromatography-Tandem Mass Spectrometry

BACKGROUND

A rapid and accurate measurement approach for 17α-hydroxyprogesterone (17-OHP) and related steroids in amount/volume-limited clinic samples is of importance for precise newborn diagnosis of congenital adrenal hyperplasia (CAH) and its subtypes in clinic.

METHODS

Sixteen steroids (17-OHP, androstenedione, cortisol, tetrahydro-11-deoxycortisol, pregnenolone, progesterone, 11-deoxycorticosterone, corticosterone, 21-deoxycortisol, 11-deoxycortisol, dehydroepiandrosterone, testosterone, aldosterone, 17α-hydroxypregnenolone, dihydrotestosterone and 18-hydroxycorticosterone) were included in the panel of high-throughput microbore ultra-performance liquid chromatography-tandem mass spectrometry. Samples were collected from 126 normal subjects and 65 patients including different subtypes of CAH.

RESULTS

The method was validated with satisfactory analytical performance in linearity, repeatability, recovery and limit of detection. Reference intervals for 16 steroids were established by quantifying the level of steroids detected in normal infants. The applicability of the method was tested by differentiating steroid metabolic characteristics between normal infants and infants with CAH, as well as between infants with different CAH subtypes. The relevance of 17-OHP, 21-deoxycortisol, and 17-OHP/11-deoxycortisol for 21-hydroxylase deficiency screening was demonstrated. The level of 11-deoxycorticosterone, 11-deoxycortisol, progesterone and androstenedione can be used for the diagnosis of different rare subtypes of CAH.

CONCLUSION

This study provides a strategy for highly efficient steroid analysis of amount/volume-limited clinic samples and holds great potential for clinical diagnosis of CAH.

The High Relevance of 21-Deoxycortisol, (Androstenedione + 17α-Hydroxyprogesterone)/Cortisol, and 11-Deoxycortisol/17α-Hydroxyprogesterone for Newborn Screening of 21-Hydroxylase Deficiency

CONTEXT

There are limited reports on the detailed examination of steroid profiles for setting algorithms for 21-hydroxylase deficiency (21OHD) screening by liquid chromatography-tandem mass spectrometry (LC-MS/MS).

OBJECTIVE

We aimed to define an algorithm for newborn screening of 21OHD by LC-MS/MS, measuring a total of 2077 dried blood spot samples in Tokyo.

METHODS

Five steroids (17α-hydroxyprogesterone [17αOHP], 21-deoxycortisol [21DOF], 11-deoxycortisol [11DOF], androstenedione [4AD], and cortisol [F]) were included in the panel of LC-MS/MS. Samples from 2 cohorts were assayed: Cohort A, 63 "screening positive" neonates who were referred to an endocrinologist (n = 26 with 21OHD; n = 37 false-positive; obtained from 2015 to 2020); and Cohort B, samples (n = 2014) with 17αOHP values in the 97th percentile or above, in the first-tier test with 17αOHP ELISA from 2020 to 2021.

RESULTS

Analysis of Cohort A revealed that the 3 indexes 21DOF, 11DOF/17αOHP, and (4AD + 17αOHP)/F had higher area under the curve (AUC) values (0.999, 0.997, 0.989, respectively), while the 17αOHP AUC was lower (0.970). Accordingly, in addition to 17αOHP, the 3 markers were included for defining the screening algorithm. The assay of Cohort B revealed that the new algorithm gave 92% of predicted positive predictive value without false-negative cases. We also determined the reference values for the 5 steroids at 4 to 7 days after birth, according to sex and gestational age (GA), revealing extremely low levels of 21DOF at any GA irrespective of sex differences.

CONCLUSION

Our study demonstrated the high relevance of 21DOF, (4AD + 17αOHP)/F, and 11DOF/17αOHP, rather than 17αOHP, for 21OHD screening.

Birth Weight- or Gestational Age-adjusted Second-tier LCMSMS Cutoffs Improve Newborn Screening for CAH in New Zealand

CONTEXT

The positive predictive value of newborn screening for congenital adrenal hyperplasia (CAH) in New Zealand is approximately 10%. The use of a second tier liquid chromatography-tandem mass spectrometry bloodspot steroid profile test with birth weight- or gestational age-adjusted screening cutoffs may result in further screening improvements.

METHODS

Three years of newborn screening data with additional second-tier steroid metabolites was evaluated (n = 167 672 births). Data from babies with a negative screening test and confirmed CAH cases were compared. First- and second-tier steroid measurements were correlated with both birth weight and gestational age. Analysis of variance was used to determine birth weight and gestational age groups. Screening cutoffs were determined and applied retrospectively to model screening performance.

RESULTS

First-tier immunoassay data correlated better with gestational age than with birth weight, but there was no difference with second-tier steroid measurements. Four distinct birth weight and gestational age groups were established for 17-hydroxyprogesterone and a steroid ratio measurement. Application of 97.5th percentile second-tier birth weight- or gestational age-adjusted cutoffs would result in 10 positive tests over the period of the study with 8 true-positive screens and 2 false-positive tests. The positive predictive value of screening would be increased from 10.8% to 80%.

CONCLUSIONS

The use of either birth weight- or gestational age-adjusted cutoffs for second-tier screening tests can significantly reduce the false positive rate of newborn screening for CAH in New Zealand without loss in screening sensitivity.

Implementing steroid profiling by liquid chromatography-tandem mass spectrometry improves newborn screening for congenital adrenal hyperplasia in New Zealand

OBJECTIVE

To evaluate the impact of a liquid chromatography-tandem mass spectrometry (LCMSMS) second-tier test on newborn screening for congenital adrenal hyperplasia due to 21-hydroxylase deficiency (CAH) in New Zealand.

DESIGN

In a prospective study, a LCMSMS method to measure 17-hydroxyprogesterone (17OHP) was adapted to measure four additional steroids. Steroid concentrations were collected on all second-tier CAH screening tests while protocols remained unchanged. Steroid ratio parameters with recommended or published screening cuts-offs were evaluated for their impact on newborn screening performance.

MEASUREMENTS

Precision, accuracy, linearity and recovery of the second-tier LCMSMS method were evaluated. Second-tier specimens were divided in 3 groups; newborn screening bloodspots from neonates with confirmed CAH (n = 7) and 2 groups specimens from neonates with a birthweight (BW) ≤1500 g (n = 795) and with a BW > 1500 g (n = 806) with a negative newborn screening test. Six protocols using four steroid ratio parameters were evaluated. The sensitivity, specificity, false positive rate and positive predictive value of screening was calculated for each protocol.

RESULTS

The LCMSMS method was sufficiently accurate and precise to be used as a second-tier test for CAH. Screening sensitivity remained at 100% for each protocol apart from (17OHP + androstenedione)/cortisol when the highest cut-off of 3.75 was applied. The false positive rate was significantly improved when (17OHP + androstenedione)/cortisol and (17OHP + 21-deoxycortisol)/cortisol were evaluated with cut-offs of 2.5 and 1.5 respectively (P < .01) and both with a positive predictive value of 64%.

CONCLUSIONS

A second-tier LCMSMS newborn screening test for CAH offers significant improvements to screening specificity without any other changes to screening protocols.

Quantification of BNN27, a novel neuroprotective 17-spiroepoxy dehydroepiandrosterone derivative in the blood and retina of rodents, after single intraperitoneal administration

BNN27 is a novel 17‐spiroepoxy derivative of the neurosteroid Dehydroepiandrosterone with neuroprotective properties. The purpose of this study was the detection and quantification of BNN27 after single intraperitoneal administration, in the serum and retina of normal rodents. Forty‐two C57BL/6 mice and 48 Sprague–Dawley rats were used for the quantification of BNN27 in the blood serum and retina, respectively. BNN27 was injected intraperitoneally (i.p.) at concentrations of 100 and 30 mg/kg of body weight (b.w.), respectively. The blood was collected with retro‐orbital bleeding and the retina was isolated after enucleation at various time points. The molecule concentrations were measured with Liquid chromatography‐mass spectrometry (LC‐MS). Non‐compartmental analysis was used to determine pharmacokinetic parameters. BNN27 was found to have an elimination constant k_el = 0.465 h⁻¹ and mean residence time (MRT) 2.154 h in the mouse serum. The maximum concentration (C_max) in the retina was detected at 2 h (tCmax) after intraperitoneal administration and was equal to 1100 ng/g. BNN27 is rapidly eliminated from both blood and retina. In the retina specifically, it is undetectable 6 h after injection. BNN27 shows a rapid systemic elimination as anticipated by its small size and lipophilicity. It is measurable in small peripheral tissues such as the rat retina, after one single i.p. injection, using a simple method such as LC‐MS. Its detection in the retina corroborates the existing biological data that the molecule crosses the blood–retinal barrier, highlighting it as a potential neuroprotective agent for retinal disease.

Advancement in steroid hormone analysis by LC-MS/MS in clinical routine diagnostics - A three year recap from serum cortisol to dried blood 17α-hydroxyprogesterone

Steroid analysis by LC-MS/MS in daily clinical routine diagnostics requires high-throughput conditions including fast chromatographic separation. Hereby, signal interferences may occur due to limited specificity in complex biologic matrices. During the last three years of routine steroid analysis in our laboratory and roughly 50,000 measurements, about 1% was affected by interferences, mainly serum cortisol (>90%) and dried blood 17α-hydroxyprogesterone (17-OHP). To overcome specificity problems, enhanced chromatography, ionization polarity switching, and detection via two-stage fragmentation (MS³) using a quadrupole linear ion trap were investigated in our study. Signal interferences of serum cortisol were eliminated by applying a protocol for automated method switching without changing the basic high-throughput LC-MS/MS setup. This approach includes negative ionization and extended chromatography from 4 to 6.6 min using the fourfold column length. From 9 samples affected by cortisol interference using the high-throughput method, 8 could be reliably analyzed applying the method switching protocol. Moreover, the applicability of the high-throughput method as second tier analysis in congenital adrenal hyperplasia (CAH) diagnostics from dried blood was verified with 100% diagnostic specificity. In addition, the combination of fast LC and MS³ detection enables specific quantitation of 17-OHP from dried blood spots on a screening time scale. This approach may be an alternative to the newborn screening for CAH by immunoassay due to its higher specificity, reducing the number of false positive results by 90%. In this work we recap experiences from three years of clinical routine steroid analysis via LC-MS/MS and present a unique analytical setup that enables both high-throughput and enhanced resolution analysis of steroid hormones in serum and dried blood.

High frequency of non-classical congenital adrenal hyperplasia form among children with persistently elevated levels of 17-hydroxyprogesterone after newborn screening

Background Early diagnosis after newborn screening (NBS) for congenital adrenal hyperplasia (CAH) allows proper treatment, reducing mortality rates and preventing development of hyperandrogenic manifestations and incorrect sex assignment at birth. Despite the high NBS sensitivity to detect CAH classical forms, one of the main issues is identifying asymptomatic children who remained with increased 17-hydroxyprogesterone (17-OHP) levels. In this study, we aimed to contribute to understanding the diagnosis of these children. Methods Children with increased serum 17-OHP levels, and without disease-related clinical features during follow-up, underwent the entire CYP21A2 gene sequencing and multiplex ligation-dependent probe amplification (MLPA) analysis (SALSA MLPA P050B CAH). Patients' genotypes were subsequently sorted as compatible with CAH disease, and children were evaluated to determine the clinical status. Results During the study period, 106,476 newborns underwent CAH NBS. During follow-up, 328 children (0.3%) were identified as having false-positive tests and 295 were discharged after presenting with 17-OHP levels within reference values. Thirty-three remained asymptomatic and with increased serum 17-OHP levels after a mean follow-up of 3.4 years, and were subjected to molecular analysis. Seventeen out of the 33 children carried mutations: seven in the heterozygous state, nine carried non-classical genotypes and the remaining child carried a classical genotype. Conclusions We found a high frequency of non-classical CAH (NCCAH) diagnosis among children with persistent elevation of 17-OHP levels. Our findings support molecular study as decisive for elucidating diagnosis in these asymptomatic children. Molecular analysis as a confirmatory test is relevant to guide their follow-up, allows genetic counseling and avoids over treating NCCAH form.

Dried Blood Spot Multiplexed Steroid Profiling Using Liquid Chromatography Tandem Mass Spectrometry in Korean Neonates

Background

Screening for congenital adrenal hyperplasia (CAH) using immunoassays for 17α-hydroxyprogesterone generates many false-positive results. We developed and validated a liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay for simultaneous quantification of nine steroid hormones in dried blood spot (DBS) samples, and established reference intervals for these hormones.

Methods

We examined our method for linearity, precision, accuracy, extraction recovery, and matrix effects and determined the reference intervals of cortisol, 17α-hydroxyproges-terone, 11-deoxycortisol, 21-deoxycortisol, androstenedione, corticosterone, 11-deoxycorticosterone, testosterone, and progesterone in 1,146 DBS samples (from 272 preterm and 874 full-term neonates). Immunoassay and LC-MS/MS methods were compared for 17α-hydroxyprogesterone. Fourteen additional samples were tested to validate the clinical applicability of the LC-MS/MS method.

Results

The linearity range was 2.8–828.0 nmol/L for cortisol and 0.9–40.0 nmol/L for the other steroids (R²>0.99). Intra-day and inter-day precision CVs were 2.52–12.26% and 3.53–17.12%, respectively. Accuracy was 80.81–99.94%, and extraction recovery and matrix effects were 88.0–125.4% and 61.7–74.2%, respectively. There was a negative bias, with higher values measured by immunoassay compared with LC-MS/MS (r=0.8104, P<0.0001). The LC-MS/MS method was successfully applied to the analysis of nine steroids in DBS for screening and diagnosis of CAH using the 14 additional samples.

Conclusions

Our method enables highly sensitive and specific assessment of nine steroids from DBS and is a promising tool for clinical analysis of CAH.

Diagnostic performance of a newly developed salivary cortisol and cortisone measurement using an LC-MS/MS method with simple and rapid sample preparation

BACKGROUND

Late-night salivary cortisol level is one of the first-line tests recommended by the Endocrine Society for the diagnosis of endogenous hypercortisolism. Most routine laboratories measure cortisol levels using immunoassay tests which fail to determine low cortisol levels accurately due to the numerous interfering substances. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method with simple and rapid sample preparation was developed for the simultaneous measurement of cortisol and cortisone and its performance in the diagnosis of endogenous hypercortisolism was evaluated.

METHODS

324 late-night saliva samples were analyzed from which 272 samples were derived from patients with a suspected diagnosis of endogenous hypercortisolism. Salivary cortisol levels were assayed using an electrochemiluminescent immunoassay (ECLIA, Cortisol II, Roche), and simultaneous measurement of cortisol and cortisone was performed using an LC-MS/MS method.

RESULTS

A strong correlation between cortisol results measured using ECLIA and LC-MS/MS (r ² = 0.892) was demonstrated. Receiver operating characteristics (ROC) analysis showed good diagnostic performance of cortisol and cortisone levels assayed using LC-MS/MS method and for cortisol measured using ECLIA.

CONCLUSIONS

Late-night salivary cortisol and cortisone are useful parameters for the diagnosis of hypercortisolism. Using samples obtained from patients where the diagnosis of hypercortisolism is extremely challenging cut-off values for midnight salivary cortisol and cortisone measured by LC-MS/MS method were established.

Simultaneous determination of thirteen different steroid hormones using micro UHPLC-MS/MS with on-line SPE system

Ultratrace analysis of sample components requires excellent analytical performance in terms of limits of quantitation (LOQ). Micro UHPLC coupled to sensitive tandem mass spectrometry provides state of the art solution for such analytical problems. Using on-line SPE with column switching on a micro UHPLC-MS/MS system allowed to decrease LOQ without any complex sample preparation protocol. The presented method is capable of reaching satisfactory low LOQ values for analysis of thirteen different steroid molecules from human plasma without the most commonly used off-line SPE or compound derivatization. Steroids were determined by using two simple sample preparation methods, based on lower and higher plasma steroid concentrations. In the first method, higher analyte concentrations were directly determined after protein precipitation with methanol. The organic phase obtained from the precipitation was diluted with water and directly injected into the LC-MS system. In the second method, low steroid levels were determined by concentrating the organic phase after steroid extraction. In this case, analytes were extracted with ethyl acetate and reconstituted in 90/10 water/acetonitrile following evaporation to dryness. This step provided much lower LOQs, outperforming previously published values. The method has been validated and subsequently applied to clinical laboratory measurement.

Skin-to-skin contact after birth and the natural course of neurosteroid levels in healthy term newborns

OBJECTIVE

To determine the postnatal course of neurosteroid levels in relation to gender, mode of delivery and the extent of skin-to-skin (STS) contact during the first days of life in healthy term newborns.

STUDY DESIGN

Prospective observational study of 39 neonates in which parents recorded total duration of STS in the first 2 days and nine neurosteroids (dehydroepiandrosterone-sulfate, progesterone, pregnenolone, pregnenolone-sulfate, allopregnanolone, isopregnanolone, epipregnanolone, pregnanolone and pregnanolone-sulfate) were assayed from blood samples at birth and at 1-2 days of age.

RESULTS

All nine neurosteroid levels declined significantly during the first 2 days of life. Gender did not significantly affect the change in neurosteroid levels. The decline in neurosteroid levels was generally more pronounced in vaginal deliveries, and there was a trend toward a larger decline with more exposure to STS.

CONCLUSION

Ongoing studies may better characterize the role of neurosteroids and the influence of STS in more critically ill and premature neonates.

Multiplexed steroid profiling of gluco- and mineralocorticoids pathways using a liquid chromatography tandem mass spectrometry method

Serum steroid assays are major tools in the clinical evaluation of adrenal disorders. The main adrenal steroids are routinely measured with immunoassays. However, chromatographic methods are known to offer better specificity. We report a liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay for simultaneous quantification of 15 adrenal steroids targeting the mineralo- and gluco-corticosteroid pathways. Serum steroids combined with deuterated internal standards were extracted using successive protein precipitation and solid phase extraction steps. Cortisol, cortisone, 11-deoxycortisol, 17-hydroxyprogesterone, 21-deoxycortisol, progesterone, 11-deoxycorticosterone, corticosterone, 11-dehydrocorticosterone, 18-hydroxycorticosterone, 18-hydroxy-11-deoxycorticosterone, aldosterone, dehydroepiandrosterone sulfate, testosterone and androstenedione were resolved in fourteen minutes using a BEH C18 column coupled to a methanol-ammonium formate gradient. Detection was performed using multiple reaction monitoring quantitation. Routinely determined steroid levels by immunoassays were compared to those measured by LC-MS/MS. This method was applied to assess steroid profiles in congenital adrenal hyperplasia (CAH) patients with 21-hydroxylase deficiency. Low quantification limits depending on each steroid (ranging from 0.015ng/mL for aldosterone to 20ng/mL for DHEAS) are adapted to the clinical use. Recoveries of steroids range from 64% for 21-deoxycortisol to 101% for cortisol and are fully corrected by internal standards. A good linearity with R>0.989 is obtained for each compound. The inter-day variation coefficients ranged from 4.7% for cortisol to 16.3% for 11-deoxycorticosterone. The immunoassay for cortisol (Immulite 2000, Siemens) showed acceptable agreement with LC-MS/MS (bias +7.2%). However, Bland-Altman plots revealed large negative bias for aldosterone (-33.4%, AldoCT, CisBio international), for 17-hydroxyprogesterone at concentrations below 2ng/mL (-74.1%, OHP-CT MP Biomedical), for androstenedione (-80.3%, RIA D4, Beckman Coulter) and for 11-deoxycortisol (-125.3%, Diasource Immunoassays). Finally, the analysis of samples from 21-hydroxylase defective patients demonstrated the potential usefulness of multiplexed steroid profiling for the diagnosis and/or monitoring of different forms of congenital adrenal hyperplasia. This LC-MS/MS method provides highly sensitive and specific assessments of mineralo- and glucocorticoids pathways from a small volume sample and is therefore a promising potent tool for clinical and experimental endocrine studies.

The use of mass spectrometry to analyze dried blood spots

Dried blood spots (DBS) typically consist in the deposition of small volumes of capillary blood onto dedicated paper cards. Comparatively to whole blood or plasma samples, their benefits rely in the fact that sample collection is easier and that logistic aspects related to sample storage and shipment can be relatively limited, respectively, without the need of a refrigerator or dry ice. Originally, this approach has been developed in the sixties to support the analysis of phenylalanine for the detection of phenylketonuria in newborns using bacterial inhibition test. In the nineties tandem mass spectrometry was established as the detection technique for phenylalanine and tyrosine. DBS became rapidly recognized for their clinical value: they were widely implemented in pediatric settings with mass spectrometric detection, and were closely associated to the debut of newborn screening (NBS) programs, as a part of public health policies. Since then, sample collection on paper cards has been explored with various analytical techniques in other areas more or less successfully regarding large-scale applications. Moreover, in the last 5 years a regain of interest for DBS was observed and originated from the bioanalytical community to support drug development (e.g., PK studies) or therapeutic drug monitoring mainly. Those recent applications were essentially driven by improved sensitivity of triple quadrupole mass spectrometers. This review presents an overall view of all instrumental and methodological developments for DBS analysis with mass spectrometric detection, with and without separation techniques. A general introduction to DBS will describe their advantages and historical aspects of their emergence. A second section will focus on blood collection, with a strong emphasis on specific parameters that can impact quantitative analysis, including chromatographic effects, hematocrit effects, blood effects, and analyte stability. A third part of the review is dedicated to sample preparation and will consider off-line and on-line extractions; in particular, instrumental designs that have been developed so far for DBS extraction will be detailed. Flow injection analysis and applications will be discussed in section IV. The application of surface analysis mass spectrometry (DESI, paper spray, DART, APTDCI, MALDI, LDTD-APCI, and ICP) to DBS is described in section V, while applications based on separation techniques (e.g., liquid or gas chromatography) are presented in section VI. To conclude this review, the current status of DBS analysis is summarized, and future perspectives are provided.

Determination of a steroid profile in heel prick blood using LC–MS/MS

Background: The aim of this study was to improve the sensitivity of the congenital adrenal hyperplasia (CAH) neonatal screening by including second-tier steroid profiling on a DBS using LC–MS. Results: We developed a method to measure the steroid profile in DBS and established gestational age-specific reference ranges of cortisol, cortisone, 11-deoxycortisol, 21-deoxycortisol, 17-hydroxyprogesterone, testosterone, Δ4-androstenedione, corticosterone and 11-deoxycorticosterone using 450 heel prick samples of neonates, participating in the Dutch Screening Program. Analyzing 92 cards with a positive CAH screening showed that only 21-deoxycortisol was 100% specific for diagnosed CAH patients. Conclusion: Steroid precursors can be measured in DBS and we suggest to implement the method as a second tier testing for CAH in The Netherlands.

Role of mass spectrometry in steroid assays

In addition to protein hormones, steroids measurement constitutes the basis of modern endocrinology. Immunoassays have shown their limits in this field. In contrast, mass spectrometry shows an excellent sensitivity and specificity that make it the method of choice for steroids assays. The recent introduction of UHPLC-MS is a major advance which reinforces this position. In fact, mass spectrometry provides a lot of advantages such as determination of certain steroids in saliva, diagnosis of enzyme deficiencies, or measurement of molecules previously inaccessible like aldosterone. However, standardization is still needed to ensure good comparability of results between laboratories. In the future, mass spectrometry should not replace the immunoassays but rather complement it.

Performance enhancement in the measurement of 5 endogenous steroids by LC-MS/MS combined with differential ion mobility spectrometry

BACKGROUND

Challenges for steroid analysis by LC-MS/MS include low ionization efficiency, endogenous isobars with similar fragmentation patterns and chromatographic retention. Differential ion mobility spectrometry (DMS) provides an additional degree of separation prior to MS/MS detection, and shows promise in improving specificity of analysis. We developed a sensitive and specific method for measurement of corticosterone, 11-deoxycortisol, 11-deoxycorticosterone, 17-hydroxyprogesterone and progesterone in human serum and plasma using an ABSciex 5500 mass spectrometer equipped with a differential ion mobility interface.

METHODS

250μL aliquots of serum were spiked with deuterated internal standards and extracted with MTBE. The samples were analyzed using positive mode electrospray LC-DMS-MS/MS. The method was validated and compared with immunoassays and LC-MS/MS methods of reference laboratories.

RESULTS

Inter and intra assay imprecision was <10%. Limits of quantification and detection in nmol/L were 0.18, 0.09 for corticosterone and 17-hydroxyprogesterone, 0.30, 0.16 for 11-deoxycortisol, 0.12, 0.06 for progesterone and 0.06, 0.03 for 11-deoxycorticosterone. Comparison for progesterone and 17-hydroxyprogesterone with immunoassay showed slopes of 0.97 and 1.0, intercepts of 0.16 and 0.10 and coefficients of determination (r(2)) of 0.92 and 0.97, respectively. Progesterone by immunoassay showed positive bias in samples measuring <3.18nmol/L. Reference intervals for progesterone and 11-deoxycorticosterone in post-menopausal women were found to be <2.88 and <0.28nmol/L respectively.

CONCLUSIONS

We developed and validated an LC-DMS-MS/MS method for analysis of five endogenous steroids suitable for routine measurements in clinical diagnostic laboratories. Specificity gained with DMS allows reducing the complexity of sample preparation, decreasing LC run times and increasing speed of the analysis.

Pharmacokinetic-pharmacodynamic study of subcutaneous injection of depot nandrolone decanoate using dried blood spots sampling coupled with ultrapressure liquid chromatography tandem mass spectrometry assays

CONTEXT

Testosterone (T) and nandrolone (N) esters require deep im injections by medical personnel but these often deposit injectate into sc fat so that more convenient sc self-administration may be feasible.

OBJECTIVE

To investigate the feasibility and pharmacology of sc injection of N decanoate in healthy men using dried blood spot (DBS) for frequent blood sampling without clinic visits.

SETTING AND DESIGN

Healthy male volunteers received 100 mg N decanoate by a single sc injection. Finger-prick capillary blood was spotted onto filter paper before injection daily at home for 21 d and stored at room temperature. Venous whole blood was also spotted onto filter paper before and weekly for 3 wk after injection. DBS were extracted for assay of N and T by liquid chromatography tandem mass spectrometry in a single batch with serum concentrations estimated with adjustment for capillary blood sample volume and hematocrit to define peak (N) or nadir (T) time and concentration from individual daily measurements.

RESULTS

Daily serum N peaked 2.50 ± 0.25 (SEM) ng/mL at a median (range) of 6 (4-13) days causing a reduction in serum T from 3.50 ± 0.57 ng/mL at baseline to a nadir of 0.38 ± 0.13 (SEM) ng/mL (89 ± 3% suppression) at a median (range) of 8 (5-16) days. Simultaneously sampled capillary, venous whole blood, and serum gave almost identical results for serum T and N. Finger-pricks and sc injections were well tolerated.

CONCLUSIONS

This study demonstrates that A) DBS sampling with liquid chromatography mass spectrometry steroid analysis achieves frequent time sampling in the community without requiring clinic visits, venesection, or frozen serum storage, and B) androgen esters in an oil vehicle can be delivered effectively by sc injection, thus avoiding the need for medically supervised deep-im injections.

17-Hydroxyprogesterone in children, adolescents and adults

17-Hydroxyprogesterone (17-OHP) is an intermediate steroid in the adrenal biosynthetic pathway from cholesterol to cortisol and is the substrate for steroid 21-hydroxylase. An inherited deficiency of 21-hydroxylase leads to greatly increased serum concentrations of 17-OHP, while the absence of cortisol synthesis causes an increase in adrenocorticotrophic hormone. The classical congenital adrenal hyperplasia (CAH) presents usually with virilisation of a girl at birth. Affected boys and girls can have renal salt loss within a few days if aldosterone production is also compromised. Diagnosis can be delayed in boys. A non-classical form of congenital adrenal hyperplasia (NC-CAH) presents later in life usually with androgen excess. Moderately raised or normal 17-OHP concentrations can be seen basally but, if normal and clinical suspicion is high, an ACTH stimulation test will show 17-OHP concentrations (typically >30 nmol/L) above the normal response. NC-CAH is more likely to be detected clinically in females and may be asymptomatic particularly in males until families are investigated. The prevalence of NC-CAH in women with androgen excess can be up to 9% according to ethnic background and genotype. Mutations in the 21-hydroxylase genes in NC-CAH can be found that have less deleterious effects on enzyme activity. Other less-common defects in enzymes of cortisol synthesis can be associated with moderately elevated 17-OHP. Precocious puberty, acne, hirsutism and subfertility are the commonest features of hyperandrogenism. 17-OHP is a diagnostic marker for CAH but opinions differ on the role of 17OHP or androstenedione in monitoring treatment with renin in the salt losing form. This review considers the utility of 17-OHP measurements in children, adolescents and adults.

LC–MS/MS in endocrinology: what is the profit of the last 5 years?

Currently, chromatography (GC but more commonly HPLC) is the analytical method of choice for several hormones, either because the immunoassays suffer from extensive crossreactivity or because chromatography permits simultaneous measurements of hormones. However, sometimes the conventional detection systems with HPLC methods do not meet desired specificity. With the increase of robust and affordable LC–MS/MS systems, the next step forward in specificity was taken. LC–MS/MS is rapidly being incorporated in the endocrine laboratories. To be useful in the clinical diagnostic practice, it is of utmost importance that methods are both analytically and clinically vaidated, as until now, the majority of applications of LC–MS/MS in the clinical laboratories are ‘home-made’ methods, therefore special case must be taken. This review aims to focus on Clinical and Laboratory Standards Institute or comparable validated LC–MS/MS methods for targeted hormone analysis used for diagnostic purposes in human samples, published in the last 5 years.

Multi-matrix assay of cortisol, cortisone and corticosterone using a combined MEPS-HPLC procedure

The development and validation of a bioanalytical assay for the simultaneous determination of cortisol, cortisone and corticosterone levels in several matrices, such as saliva, plasma, blood and urine samples have been described. The method is based on a rapid test which combines a microextraction by packed sorbent procedure and liquid chromatography-diode array technique. Chromatographic separation of the analytes (cortisol, cortisone and corticosterone) and the internal standard (methylprednisolone) was achieved in less than 10min on a reversed-phase pentafluorophenyl column using a mobile phase composed of phosphate buffer and acetonitrile. The assay was performed after an innovative microextraction procedure by means of C8 sorbent which guaranteed good clean-up of the matrices and satisfactory extraction yield of the analytes. Moreover, the method gave linear results over a range of 5-100ngmL(-1) and showed good selectivity and precision. This method was successfully applied for quantifying corticosteroids in specific matrices derived from some healthy volunteers in comparison to two socially diversified groups, namely former heroin addicts undergoing opioid replacement therapy and poly-drug abusers.

Limited response to CRH stimulation tests at 2 weeks of age in preterm infants born at less than 30 weeks of gestational age

BACKGROUND

The high incidence of glucocorticoid-responsive complications in extremely preterm infants suggests the immaturity of their adrenal function; however, knowledge of the hypothalamus-pituitary-adrenal (HPA) axis in extremely preterm infants is limited.

METHODS

To clarify the characteristics of the HPA axis in preterm very low birthweight (VLBW) infants, we performed CRH tests repeatedly: at about 2 weeks of age and at term (37-41 weeks of postmenstrual age) for 21 VLBW infants with a gestational age (GA) <30 weeks at birth.

RESULTS

Basal cortisol values at 2 weeks of age were significantly higher than those at term in VLBW infants < 30 weeks of gestation at birth (304·1 ± 146·3 nmol/l vs 184·7 ± 108·2 nmol/l). Response to corticotropin-releasing hormone (CRH) stimulation tests at 2 weeks of age was significantly lower than at term (delta cortisol 148·3 ± 90·7 nmol/l vs 271·8 ± 167·0 nmol/l, delta ACTH 3·9 ± 3·2 pmol/l vs 12·3 ± 9·2 pmol/l, respectively). We found that earlier GA contributed to the higher basal cortisol values, and antenatal glucocorticoid (AG) contributed to the lower response of cortisol to CRH tests at 2 weeks of age.

CONCLUSIONS

VLBW infants showed a characteristic pattern in the HPA axis at 2 weeks of age: higher basal cortisol values and lower response to CRH tests. This study suggested that AG was related to the lower response to CRH tests, at least partly.

Simultaneous determination of endogenous steroid hormones in human and animal plasma and serum by liquid or gas chromatography coupled to tandem mass spectrometry

Analytical methodologies based on liquid or gas chromatography coupled to tandem mass spectrometry for the simultaneous determination of two or more endogenous steroid hormones in human and animal plasma and serum has received increased attention the last few years. Especially in the clinical setting steroid profiling is of major importance in disease diagnostics. This paper discusses recent findings in such multi-steroid hormone procedures published from 2001 to 2012. The aim was to elucidate possible relationships between chosen analytical technique and the obtained analyte sensitivity for endogenous steroid hormones. By evaluating the success, at which the currently applied techniques have been utilized, more general knowledge on the field is provided. Furthermore the evaluation provides directions in which future studies may be interesting to conduct.

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

CONTEXT

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

DESIGN/METHODS

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

RESULTS

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

CONCLUSION

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

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.