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

A MinION-based Long-Read Sequencing Application With One-Step PCR for the Genetic Diagnosis of 21-Hydroxylase Deficiency

CONTEXT

Recently developed long-read sequencing (LRS) technology has been considered an option for CYP21A2 analysis. However, the clinical use of LRS for CYP21A2 analysis is limited.

OBJECTIVE

This study's objective is to develop an efficient and low-cost LRS system for CYP21A2 screening.

METHODS

A DNA fragment library was prepared in a single polymerase chain reaction (PCR) that covers the entire CYP21A2 gene and all known junctions caused by TNXB gene structural rearrangements, yielding a single 8-kb product of CYP21A2 or CYP21A1P/CYP21A2 chimera. After barcoding, the PCR products were sequenced on a MinION-based platform with Flongle Flow Cell R9.4.1 and R10.4.1.

RESULTS

The reference genotypes of 55 patients with 21-hydroxylase deficiency (21OHD) were established using the conventional method with multiplex ligation-dependent probe amplification (MLPA) and nested PCR. LRS using Flongle Flow Cell R9.4.1 yielded consistent results. Additionally, the recently updated LRS "duplex" analysis with Flongle flow cell R10.4.1 was tested to reveal an advantage of accurately sequencing a variant located on the homopolymer region. By introducing a barcode system, the cost was reduced to be comparable to that of conventional analysis. A novel single-nucleotide variation was discovered at the acceptor site of intron 7, c.940-1G > C. We also identified a subtype of the classical chimeric junction CH2, "CH2a," in the region from the latter part of intron 5 to exon 6.

CONCLUSION

We successfully established a novel low-cost and highly accurate LRS system for 21OHD genetic analysis. Our study provides insight into the feasibility of LRS for diagnosing 21OHD and other genetic diseases caused by structural rearrangements.

Best Practice for Identification of Classical 21-Hydroxylase Deficiency Should Include 21 Deoxycortisol Analysis with Appropriate Isomeric Steroid Separation

There are mixed reports on the inclusion and use of 21 deoxycortisol (21DF) as the primary decision marker for classical 21-hydroxylase deficiency. We hypothesize that this may be due to insufficient recognition of the presence and chromatographic separation of isomeric steroids. The aim of this study was to determine the comparative utility of 21DF for screening and diagnosis of CAH due to classical 21-hydroxylase deficiency using a second-tier LC-MS/MS method that included the separation of isomeric steroids to 17OHP and 21DF. For each baby sample, one 3.2 mm dried blood spot was eluted in a methanolic solution containing isotopically matched internal standards. Data were interrogated by univariate and receiver operator characteristic analysis. Steroid profile results were generated for 924 non-CAH baby samples (median gestational age 37 weeks, range 22 to 43 weeks) and 17 babies with 21-hydroxylase deficiency. The ROC curves demonstrated 21DF to have the best sensitivity and specificity for the diagnosis of classical 21-hydroxylase deficiency with an AUC = 1.0. The heatmap showed the very strong correlation (r = 0.83) between 17OHP and 21DF. Our data support 21DF as a robust marker for CAH due to 21-hydroxylase deficiency. We recommend that 21DF be incorporated into routine newborn screening panels as part of the second-tier LC-MS/MS method, follow-up plasma steroid panels, and external quality assurance material.

Optimization of bioanalysis of dried blood samples

INTRODUCTION

Pharmacokinetic/pharmacodynamic modelling has emerged as a valuable technique for understanding drug exposure and response relationships in drug development. Pharmacokinetic data are often obtained by taking multiple blood samples, which may disturb physiological parameters and complicate study designs. Wearable automatic blood sampling systems can improve this limitation by collecting dried blood samples at programmable time points without disrupting cardiovascular parameters. It is the objective of this study to evaluate the bioanalysis of DBS in comparison to conventional blood sampling techniques and to optimize the recovery of various compounds spiked into canine blood dried on filter paper tape.

METHODS

Incubated blood samples from Beagle dogs were spiked with 16 different compounds and half of the whole blood sample was centrifuged to obtain plasma. After the dried blood sample drops were dried, liquid chromatography-mass spectrometry methods were used to analyze the samples. The study explored different anticoagulants, sample preparation methods and technical approaches to best determine the compound concentrations in dried blood samples.

RESULTS

With the two anticoagulants tested and using the optimized sample preparation methods and technical approaches we employed, the bioanalysis of dried blood samples can provide equivalent results to conventional blood sampling techniques.

DISCUSSION

Automated blood sampling systems have the potential to provide increased numbers of blood samples, providing substantially more Pharmacokinetic data within safety pharmacology studies without disrupting physiological parameters. They can provide a viable alternative to traditional methods of obtaining blood for various other types of studies or analyses.

Simultaneous measurement of 19 steroid hormones in dried blood spots using ultra-performance liquid chromatography-tandem mass spectrometry

A rapid and accurate ultra-performance liquid chromatography-tandem-mass spectrometry (UPLC-MS/MS) method was developed for the measurement of 19 steroid hormones in dried blood spots and to achieve the highly traceable analysis of steroid hormones in dried blood samples. In this method, a BEH C8 column and UPLC-MS/MS were used for the separation of the steroid hormones. The extraction process was simple and accurate. The distribution ranges of 19 steroid hormones in four healthy individuals (2 males and 2 females) were determined simultaneously by positive ionization mode (ESI⁺) and negative ionization mode (ESI^-) analysis, which were recorded by multiple reaction monitoring (MRM) modes. The linearity of the standard curves of 19 steroid hormones in dried blood spots was good, and the linear correlation coefficients R² were all ≥0.997. Meanwhile, the matrix effect of the method ranged from 87.1% to 131.3%. Across the analytical range, the inter-assay coefficient of variation (CV) was <12.07% and the intra-assay CV was <18.16%. The spiked recovery was >67.33%. The distribution ranges of 19 steroid hormones in four healthy individuals were in agreement with those in previous reports. A UPLC-MS/MS method for the simultaneous measurement of 19 steroid hormones in dried blood spots was developed to achieve traceable analysis of steroid hormones in dried blood samples.

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.

Comprehensive Evaluation of the NeoBase 2 Non-derivatized MSMS Assay and Exploration of Analytes With Significantly Different Concentrations Between Term and Preterm Neonates

Background

Despite the popularity of the NeoBase 2 Non-derivatized MSMS assay (PerkinElmer, Turku, Finland), there are no reports of its comprehensive evaluation, including the ability to distinguish transient tyrosinemia of the newborn (TTN) from tyrosinemia type 1 (TYR 1) using succinylacetone (SUAC). No newborn screening (NBS) cutoffs for preterm neonates in the Korean population have been suggested. We evaluated the NeoBase 2 assay and identified analytes requiring different cutoffs in preterm neonates.

Methods

Residual NBS dried blood spot samples and proficiency testing (PT) materials of the Newborn Screening Quality Assurance Program and the Korean Association of External Quality Assessment Service were used. Precision, accuracy, limit of detection (LOD), lower limit of quantification (LLOQ), linearity, recovery, carryover, and performance of SUAC were evaluated. Cutoffs were determined, and analytes requiring different cutoffs in preterm neonates were investigated.

Results

Mean CVs for within-run and between-day precision were within 15%. Accuracy analysis indicated high agreement with in-house derivatized assay results and results of other PT participants. All analytes demonstrated acceptable LOD, LLOQ, and linearity. Recoveries were acceptable, except for SUAC. Carryover was negligible. Cutoffs were established for all analytes; Tyr, adenosine, and C20:0-lysophosphatidylcholine required different cutoffs in preterm neonates. Differential diagnosis of TYR 1 and TTN was successful with simultaneous Tyr and SUAC measurement.

Conclusions

The NeoBase 2 assay demonstrated satisfactory performance. The additional analytes provide a wider diagnostic coverage, and the simultaneous measurement of Tyr and SUAC is efficient in excluding TYR 1. The new cutoffs for preterm neonates may decrease false-positive rates, without compromising diagnostic sensitivity.

Clinical Usefulness of Ultraperformance Liquid Chromatography-Tandem Mass Spectrometry Method for Low Serum Testosterone Measurement

Background

Mass spectrometry methods exhibit higher accuracy and lower variability than immunoassays at low testosterone concentrations. We developed and validated an ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) assay for quantifying serum total testosterone.

Methods

We used an ExionLC UPLC (Sciex, Framingham, MA, USA) system and a Sciex Triple Quad 6500+ (Sciex) MS/MS system in electrospray ionization and positive ion modes with multiple reaction monitoring transitions to evaluate precision, accuracy, linearity, lower limit of quantitation (LLOQ), carryover, ion suppression, stability, and reference intervals. For method comparison, we measured serum testosterone concentrations using this method in 40 subjects whose testosterone concentrations ranged from 0.14 to 55.48 nmol/L as determined using the Architect i2000 immunoassay (Abbott Diagnostics, Abbott Park, IL, USA) and in an additional 160 sera with testosterone concentrations <1.67 nmol/L.

Results

The intra- and inter-run precision CVs were <2.81%, and the accuracy bias values were <3.85%, which were all acceptable. The verified linear interval was 0.03-180.84 nmol/L; the LLOQ was 0.03 nmol/L. No significant carryover and ion suppression were observed. The testosterone in serum was stable at 4°C, at -20°C, and after three freeze-thaw cycles. The reference intervals were successfully verified. The correlation was good at testosterone concentrations of 0.14-55.48 nmol/L; however, the Architect assay showed positive percent bias at concentrations <1.67 nmol/L.

Conclusions

The UPLC-MS/MS assay shows acceptable performance, with a lower LLOQ than the immunoassay. This method will enable the quantitation of low testosterone concentrations.

A novel device for serial venous blood sampling in a canine model

Diagnostic serial venous blood sampling has the potential to introduce stress-related artifactual elements into the analytical results. We have evaluated the use of a wearable automated serial blood sampling device in a canine model that obviates a need for multiple manual venipuncture. Efficacy in measuring cortisol levels during prolonged serial blood sampling is described. Automated serial blood sampling from the jugular vein was performed in two Beagle dogs. Over two separate 22-h periods, serial blood samples were withdrawn for routine cell counting and blood chemistries from each animal, whilst animal behavior along with durability of catheter placement and tolerability by the vascular system were assessed. During the study, no behavioral changes attributed to the serial blood sampling device were seen and no stress-related deviations from normal blood cell counts and cortisol levels were detected. Minor erythema was eident at the sites of catheter placement, which was consistent with the presence of an indwelling catheter. The wearable, serial blood sampling device performed well and was tolerated by the animals without stress-related changes in blood analysis or behavioral observation. This study has demonstrated the potential significant benefit of the Fluispotter® device for serial blood sampling in veterinary and clinical settings. The samples collected are free from stress-related signatures in blood chemistry otherwise common to serial blood sampling protocols requiring repeated venipuncture. This device has valuable implications for use in routine preclinical pharmacology and toxicology studies.

Solutions for hematocrit bias in dried blood spot hormone analysis

Over the last years, dried blood spot (DBS) sampling has gained significant interest due to development of analytical techniques combined with DBS, the simplicity and low cost of the method. Despite its wide use, DBS sampling can lead to inaccurate results due to the impact of the hematocrit (Hct) on the analysis. Some analytes have shown to be hardly impacted by Hct values. However, in other cases, a significant impact of Hct is observed, which requires the use of alternative approaches to circumvent this issue. This review describes the possible impact of Hct-related bias in DBS sampling in the context of hormone analysis and discusses the different methodologies that can be used to overcome this bias to ensure accurate results.

Comparison of different preparation techniques of dried blood spot quality controls in newborn screening for congenital adrenal hyperplasia

In newborn screening, samples suspected for congenital adrenal hyperplasia (CAH), a potentially lethal inborn error of steroid biosynthesis, need to be confirmed using liquid chromatography-tandem mass spectrometry. Daily quality controls (QCs) for the 2nd-tier CAH assay are not commercially available and are therefore generally prepared within the laboratory. For the first time, we aimed to compare five different QC preparation approaches used in routine diagnostics for CAH on the concentrations of cortisol, 21-deoxycortisol, 11-deoxycortisol, 4-androstenedione and 17-hydroxyprogesterone in dried blood spots. The techniques from Prep1 to Prep5 were tested at two analyte concentrations by spiking aliquots of a steroid-depleted blood, derived from washed erythrocyte suspension and steroid-depleted serum. The preparation processes differed in the sequence of the preparation steps and whether freeze-thaw cycles were used to facilitate blood homogeneity. The five types of dried blood spot QCs were assayed and quantitated in duplicate on five different days using a single calibration row per day. Inter-assay variations less than 15% and concentrations within ±15% of the nominal values were considered acceptable. Results obtained by means of the four dried blood spot QC preparation techniques (Prep1, Prep2, Prep4 and Prep5) were statistically similar and remained within the ±15% ranges in terms of both reproducibility and nominal values. However, concentration results for Prep3 (spiking prior to three freeze-thaw cycles) were significantly lower than the nominal values in this setting, with differences exceeding the ±15% range in many cases despite acceptable inter-assay variations. These findings have implications for the in-house preparation of QC samples in laboratory developed tests for CAH, including 2nd-tier assays in newborn screening.

Adrenal Cushing Syndrome Diagnosed During Pregnancy: Successful Medical Management With Metyrapone

Adrenal Cushing syndrome during pregnancy is rare, and there is limited information on the effect and safety of metyrapone treatment both for mother and fetus. We present a 24-year-old woman diagnosed with adrenal Cushing syndrome at the end of the second trimester. We elected treatment with metyrapone titrated to 250 mg 3 times daily, resulting in good clinical response and maternal serum and saliva cortisol levels in the upper half of the normal pregnancy range. A healthy male infant was born at 35 weeks’ gestation, with no clinical signs of adrenal insufficiency, this despite a low cortisol of 5 nmol/L on the first day of life. We measured metyrapone in maternal and umbilical cord blood samples, demonstrating fetal venous metyrapone levels similar to maternal venous concentration, and a fetal arterial cord concentration at about 60% of the fetal venous cord concentration. This case demonstrates that salivary cortisol levels may be used to monitor the effect of metyrapone on adrenal Cushing syndrome during pregnancy. We show, for the first time in humans, that metyrapone does cross the placenta and may suppress fetal cortisol production without necessarily causing clinical signs of adrenal insufficiency.

Evaluation of a Two-Tier Screening Pathway for Congenital Adrenal Hyperplasia in the New South Wales Newborn Screening Programme

In Australia, all newborns born in New South Wales (NSW) and the Australia Capital Territory (ACT) have been offered screening for rare congenital conditions through the NSW Newborn Screening Programme since 1964. Following the development of the Australian Newborn Bloodspot Screening National Policy Framework, screening for congenital adrenal hyperplasia (CAH) was included in May 2018. As part of the assessment for addition of CAH, the national working group recommended a two-tier screening protocol determining 17α-hydroxyprogesterone (17OHP) concentration by immunoassay followed by steroid profile. A total of 202,960 newborns were screened from the 1 May 2018 to the 30 April 2020. A threshold level of 17OHP from first tier immunoassay over 22 nmol/L and/or top 2% of the daily assay was further tested using liquid chromatography tandem mass spectrometry (LC-MS/MS) steroid profiling for 17OHP (MS17OHP), androstenedione (A4) and cortisol. Samples with a ratio of (MS17OHP + A4)/cortisol > 2 and MS17OHP > 200 nmol/L were considered as presumptive positive. These newborns were referred for clinical review with a request for diagnostic testing and a confirmatory repeat dried blood spot (DBS). There were 10 newborns diagnosed with CAH, (9 newborns with salt wasting CAH). So far, no known false negatives have been notified, and the protocol has a sensitivity of 100%, specificity of 99.9% and a positive predictive value of 71.4%. All confirmed cases commenced treatment by day 11, with none reported as having an adrenal crisis by the start of treatment.

Quantitative microsampling for bioanalytical applications related to the SARS-CoV-2 pandemic: Usefulness, benefits and pitfalls

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SARS-CoV-2 emergency sparks the need for diagnostic and therapeutic actions.

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Microsampling is emerging in as an attractive alternative to traditional sampling.

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Advantages and challenges of the main microsampling techniques are reported.

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Available microsampling applications of interest for SARS-CoV-2 are described.

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Most useful information for researchers and clinicians are gathered and provided.

The multiple pathological effects of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, and its total novelty, mean that currently a lot of diagnostic and therapeutic tools, established and tentative alike, are needed to treat patients in a timely, effective way. In order to make these tools more reliable, faster and more feasible, biological fluid microsampling techniques could provide many advantages. In this review, the most important microsampling techniques are considered (dried matrix spots, volumetric absorptive microsampling, microfluidics and capillary microsampling, solid phase microextraction) and their respective advantages and disadvantages laid out. Moreover, currently available microsampling applications of interest for SARS-CoV-2 therapy are described, in order to make them as much widely known as possible, hopefully providing useful information to researchers and clinicians alike.

The Potential of Steroid Profiling by Mass Spectrometry in the Management of Adrenocortical Carcinoma

Radiological and endocrinological work up of adrenal neoplasms is aimed at distinguishing between frequent non-functioning adenomas and rare but very aggressive adrenocortical carcinoma (ACC). Relevant research has addressed the identification of molecular, genetic and hormonal markers that could have clinical significance for malignancy, as well as a prognostic value. Regarding endocrine aspects, attention has been paid to the pattern of steroid secretion that can be affected by altered steroidogenic pathway in ACC. The advent of mass spectrometry techniques has overcome many limitations usually associated with immunoassays, allowing the determination of both common and rarely measured steroids in a single analysis with high specificity and sensitivity. Indeed, mass spectrometry strategies may be able to identify an individualized steroid profile of ACC, allowing a rapid diagnosis and a specific follow-up. In this review, insights, strengths and limitations of mass spectrometry-based approaches in steroid profiling, as well as of immunoassay in steroid measurements, will be specifically discussed. Moreover, the latest findings on steroid profiling by mass spectrometry-based techniques, the most promising analytical tool, will be summarized to evaluate if steroid profiling might be the clue for solving the clinical dilemma in differentiating ACC from non-functioning adrenocortical adenomas (ACA).

Fluispotter, a novel automated and wearable device for accurate volume serial dried blood spot sampling

Aim: A novel automated serial dried blood spot (DBS) sampler, 'Fluispotter', was tested for its sampling performance. Materials & methods: An LC-MS/MS method was developed for the analysis of cortisol in DBS samples serially spotted by Fluispotter. The cortisol concentrations in 148 paired DBS and plasma samples were compared across a hematocrit (HCT) range of 22-55%. Results: The interassay accuracy and precision were <10%. Overall assay bias was negligible across the HCTs tested when analyzing the whole-spot DBS samples. The accuracy and precision of the blood volume in 10 μl DBS samples spotted by Fluispotters and micropipettes were within 3%. Deming regression and Bland-Altman analysis showed a good agreement of DBS-predicted and measured plasma cortisol. Conclusion: The Fluispotter performed serial sampling with high accuracy and precision of the sample blood volume.

Storage stability of five steroids and in dried blood spots for newborn screening and retrospective diagnosis of congenital adrenal hyperplasia

Congenital adrenal hyperplasia (CAH) is a severe inherited disorder of cortisol biosynthesis that is potentially lethal or can seriously affect quality of life. For the first time, we aimed to assess the stability of 21-deoxycortisol (21Deox), 11-deoxycortisol (11Deox), 4-androstenedione (4AD), 17-hydroxyprogesterone (17OHP) and cortisol (Cort), diagnostic for CAH, in dried blood spots (DBSs) during a 1 year storage at different temperatures. Spiked DBS samples were stored at room temperature, 4 °C, -20 °C or -70 °C, respectively and analyzed in triplicates using liquid chromatography–tandem mass spectrometry at Weeks 0, 1, 2, 3 and 4, Month 6 and Year 1. Analyte levels within ±15% vs the baseline were considered stable. Our observations show that 21Deox, 4AD and 17OHP were not significantly changed for 1 year even at room temperature at either analyte levels. In contrast, Cort required storage at 4 °C, -20 °C or -70 °C for long-term stability, being significantly decreased at room temperature from Month 6 (p<0.01) in both the 30(60) nM and the 90(180) nM samples. 11Deox was significantly decreased at room temperature at Year 1 (p<0.01) and only in the 30(60) nM samples. Thus, all biomarkers were stable for up to 1 year at 4 °C, -20 °C or -70 °C and at least for 4 weeks at room temperature. These findings have implications for analyses of stored DBS samples in 2^nd-tier assays in newborn screening and for retrospective CAH studies.

Congenital Adrenal Hyperplasias Presenting in the Newborn and Young Infant

Congenital adrenal hyperplasia includes autosomal recessive conditions that affect the adrenal cortex steroidogenic enzymes (cholesterol side-chain cleavage enzyme; 3β-hydroxysteroid dehydrogenase; 17α-hydroxylase/17,20 lyase; P450 oxidoreductase; 21-hydroxylase; and 11β-hydroxylase) and proteins (steroidogenic acute regulatory protein). These are located within the three major pathways of the steroidogenic apparatus involved in the production of mineralocorticoids, glucocorticoids, and androgens. Many countries have introduced newborn screening program (NSP) based on 17-OH-progesterone (17-OHP) immunoassays on dried blood spots, which enable faster diagnosis and treatment of the most severe forms of 21-hydroxylase deficiency (21-OHD). However, in several others, the use of this diagnostic tool has not yet been implemented and clinical diagnosis remains challenging, especially for males. Furthermore, less severe classic forms of 21-OHD and other rarer types of CAHs are not identified by NSP. The aim of this mini review is to highlight both the main clinical characteristics and therapeutic options of these conditions, which may be useful for a differential diagnosis in the neonatal period, while contributing to the biochemical evolution taking place in the steroidogenic field. Currently, chromatographic techniques coupled with tandem mass spectrometry are gaining attention due to an increase in the reliability of the test results of NPS for detecting 21-OHD. Furthermore, the possibility of identifying CAH patients that are not affected by 21-OHD but presenting elevated levels of 17-OHP by NSP and the opportunity to include the recently investigated 11-oxygenated androgens in the steroid profiles are promising tools for a more precise diagnosis and monitoring of some of these conditions.