液相色谱串联质谱法检测人血清雌酮、雌二醇

目的建立同时测定人血清中雌酮(E1)及雌二醇(E2)水平的液相色谱串联质谱(LC-MS/MS)法,并初步应用于临床血清样品的雌激素检测。方法血清样品经乙酸乙酯提取,丹磺酰氯衍生化后进行LC-MS/MS分析。用Agilent ZORBAX SBC18色谱柱进行线性梯度洗脱,流动相为乙腈(0.05%甲酸)-水(0.05%甲酸),流速为0.3 m L/min。用多重反应离子监测(MRM)正离子模式对血清中的E1、E2进行质谱检测,并根据"生物样品定量分析方法验证指导原则(中国药典,2015)"对该方法的特异性、线性范围、灵敏度、精密度、提取回收率和稳定性等进行评价。用本法对172例健康成年女性血清标本进行E1、E2检测,用百分位数法计算不同月经周期E1、E2的浓度区间。结果 LC-MS/MS法可同时检测人血清中E1、E2的含量,在0.05~10 nmol/L范围内线性关系良好。该法的定量限为0.05 nmol/L,日内与日间不精密度均小于15%,稳定性良好。初步临床应用显示,用LC-MS/MS法计算所得的E1、E2浓度区间符合女性月经周期生理性变化规律。结论 LC-MS/MS法能有效分离并定量检测人血清中E1、E2的浓度水平,其线性范围广、灵敏度高、精密度好,有望作为临床血清雌激素检测的参考方法。     

人血清哇巴因UPLC-MS/MS检测方法的建立和方法比对

目的建立超高效液相色谱串联质谱(UPLC-MS/MS)检测人血清哇巴因的方法。方法采用高特异性的UPLC-MS/MS,以氘标记的哇巴因-d3作为内标。样本采用固相萃取(SPE)前处理方法,以反相色谱柱负离子模式及电喷雾电离源(ESI)检测血清哇巴因水平。对建立的方法进行方法学(基质效应、回收率、准确度、批内精密度、批间精密度及稳定性)验证。采用建立的UPLC-MS/MS方法检测20名体检健康者及40例高血压患者血清哇巴因水平,并与酶联免疫吸附试验(ELISA)进行比较。结果 UPLC-MS/MS检测血清哇巴因的标准曲线范围为0.02～5.0 ng/mL,最低定量检测限(LLOQ)为0.02ng/mL。采用ABN固相萃取小柱进行样本前处理的基质效应较小,且回收率较高,达85%。LLOQ和低值(0.06 ng/mL)、中值(0.6 ng/mL)、高值(4 ng/mL)质控品的准确度分别为108.0%、89.2%、101.0%、103.0%。3个水平质控品的批内变异系数(CV)分别为2.87%、1.95%、0.56%,批间CV分别为5.98%、1.90%、0.75%。样本室温过夜放置16 h及样本前处理后室温放置自动进样器48 h的偏差均15%。采用UPLC-MS/MS检测哇巴因,正常对照者及高血压患者血清中均未检测到哇巴因。采用ELISA测定血清哇巴因,高血压患者为0.096 ng/mL,正常对照者为0.062 ng/mL。UPLC-MS/MS检测5个水平(0.02、0.05、0.10、0.20、0.50 ng/mL)的哇巴因标准品,其测定结果与对应的哇巴因标准品浓度呈正相关,且线性较好(r20.99),准确度较高;而ELISA检测5个水平哇巴因标准品的结果均很接近(0.024 9～0.029 6 ng/mL)。结论建立了检测人血清哇巴因的UPLC-MS/MS方法,未检测到正常人及高血压患者的血清哇巴因。UPLC-MS/MS与ELISA检测血清哇巴因的结果存在较大差异。     

同位素稀释液相色谱串联质谱法测定人血清中5-甲基四氢叶酸

目的建立测定人血清中5-甲基四氢叶酸的同位素稀释液相色谱串联质谱法(ID-LC/MS/MS)。方法对5-甲基四氢叶酸纯品定性分析后,用两种不同原理(质量平衡法和定量核磁共振法)的定值方法测定纯品纯度,再以5-甲基四氢叶酸同位素标记物(~(13)C_5-5-甲基四氢叶酸)为内标物,用电喷雾三重四级杆串联质谱多重反应监测模式对6例相同水平浓度的血清进行定值及不确定度评定,并对方法的精密度、正确度、检测限、定量限进行考察。结果定性分析确认样品主成分后,质量平衡法与定量核磁共振法测定5-甲基四氢叶酸纯品的纯度为76.65%;人血清5-甲基四氢叶酸定值结果为8.22 ng/m L,扩展不确定度为0.54 ng/m L;方法检测限为0.05 ng/m L,定量限为0.50 ng/m L,重复性与期间精密度的变异系数(CV)均在5.0%以内,用国际标准物质NIST SRM 1955进行正确度验证,3个水平测量结果均在认定值±扩展不确定度范围内。结论建立了测定人血清中5-甲基四氢叶酸的ID-LC/MS/MS法,该法特异性好,灵敏度高,可准确测定人血清中5-甲基四氢叶酸的含量。     

同位素稀释液相色谱串联质谱法测定血清睾酮

目的建立一种用同位素稀释液相色谱串联质谱法(ID-LC/MS/MS)测定血清睾酮的候选参考方法。方法以[16,17,17-d3]睾酮为内标,用重量法准确地与血清混合,用乙酸乙酯-正己烷混合溶剂提取,以羟丙基-β-环糊精水溶液对提取液作净化处理,用液相色谱串联质谱分析,质谱选择离子监测模式检测睾酮与内标的特定碎片离子,用包括法定量。结果血清睾酮测定的批内、批间和总变异系数(CV)的均值(范围)为0.84%(0.22%~2.00%)、1.01%(0.48%~2.37%)和1.37%(0.53%~3.09%)。参考物质ERM DA-345a和NIST SRM 971测定结果与认定值的平均偏差范围为-2.0%~+1.8%。结论用ID-LC/MS/MS建立了血清睾酮的测定方法,方法准确、精密、简便,有望作为血清睾酮测定的参考方法。     

超高效液相色谱－串联质谱联用检测血清胆汁酸谱方法的建立及初步临床应用

目的 建立超高效液相色谱-串联质谱(UPLC-MS/MS)联用方法检测血清中胆汁酸表达的方法,并初步探讨胆汁酸亚型与肥胖的关系.方法 采用固相萃取方法处理血清标本,经UPLCHSS T3色谱柱梯度洗脱后,用负离子多反应监测模式对血清中的胆汁酸组分进行质谱检测,并根据中国国家食品药品监督管理局(SFDA)的指导原则对该方法的特异性、线性范围、灵敏度、不精密度和相对回收率进行性能验证.利用UPLC-MS/MS方法检测10例单纯性肥胖者和10名健康对照者血清胆汁酸浓度,并采用秩和检验进行统计分析.结果 UPLC-MS/MS方法可同时检测人血清中14种胆汁酸亚组分,在10～20 000 nmol/L范围内线性相关良好.其对不同亚组分的最低检出限(LOD)为0.02～7.90 nmol/L,最低定量限(LOQ)为0.07～44.20 nmol/L;其日内不精密度为0.35％～12.41％;日间不精密度为1.11％ ～13.04％;相对回收率为89.8％～114.6％.初步临床应用显示,单纯性肥胖者及健康对照者血清胆汁酸谱色谱图有一定差异,单纯性肥胖者血清中游离胆汁酸和结合胆汁酸浓度分别为0.49(0.45 ～1.90)、1.44(0.84～3.72) μmol/L,均低于健康对照组的0.98(0.53～3.06)、1.99(0.67 ～2.88) μmol/L,但差异均无统计学意义(Z=-0.958、-0.801,P均＞0.05).结论 建立的UPLC-MS/MS方法可有效分离并定量检测血清中各种胆汁酸亚型,其线性范围广、灵敏度高、精密度好,可用于临床标本游离胆汁酸和结合胆汁酸的分析测定.     

液质联用定量血清中维生素D、A、E的方法

目的本文旨在建立并验证一种准确、方便、快速同时定量人血清中四种脂溶性维生素25-羟基维生素D2(25OHVD2)、25-羟基维生素D3(25OHVD3)、维生素A、维生素E的液质联用方法,以满足临床研究、临床诊断对其检测的需求。方法 100μL血清样品经液-液萃取纯化,4种分析物经反相色谱分离、质谱MRM扫描模式下检测。采用自配并经验证的替代基质,对内源性分析物进行准确的标准曲线定量。分离定量在5min的时间里完成。结果提出并成功验证了代替基质法为基础的LC-MS/MS 4种内源性维生素的定量方法。代替基质容易配制,性能优越,定量方便。方法的检测线性范围分别为25OHVD2:0.5～50.0ng/mL,25OHVD3:2～200ng/mL,维生素A:100～10 000ng/mL,维生素E:300～30 000ng/mL。四种分析物的日内及日间精密度和准确度偏差均在±20%以内。血清样品室温、冻融及1个月长期稳定性均满足评判标准。结论实验结果说明此方法具有准确、可靠,稳定、耐用性及快速等优点,适用于临床样本的分析。     

液相色谱-串联质谱检测血浆3-甲氧酪胺方法的建立

目的建立一种稳定的检测血浆3-甲氧酪胺(3-MT)的液相色谱-串联质谱(LC-MS/MS)方法。方法对LC-MS/MS的分离条件(色谱柱、柱温、p H值)进行优化,建立检测血浆3-MT的方法,并对该方法的线性范围、回收率、精密度、最低检测下限和稳定性进行评价。结果以同位素氘代作为内标,采用BEH HILIC色谱柱进行分离。流动相为100 mmol/L甲酸铵缓冲液(p H值为3)和纯乙腈,梯度洗脱;柱温为35℃。LC-MS/MS检测3-MT的线性范围为5~1 000 pg/mL,定量检出限为5 pg/mL,天间和批间变异系数(CV)分别为6%和7%,回收率为97.1%~109.3%。由于3-MT在室温中稳定性较差,因此需冰浴送检。结论建立了检测3-MT的LC-MS/MS方法,能够灵敏、准确地检测血浆3-MT水平。     

液相色谱串联质谱法和循环酶法测定血清中同型半胱氨酸的相关性

目的分析液相色谱串联质谱(LC-MS/MS)法与循环酶法测定人血清中同型半胱氨酸(homocysteine,HCY)浓度的相关性。方法收集63例患者的血清样本,用LC-MS/MS法和循环酶法分别测定相同样本的HCY浓度,并评价2种方法的相关性。结果 LC-MS/MS法与循环酶法对HCY浓度测定的结果分别为(19.11±15.69)μmol/L和(16.95±14.41)μmol/L,差异有统计学意义(t=6.25,P0.05)。2种方法的线性回归方程为YLC-MS/MS法=1.074X循环酶法+0.892,相关系数(R)=0.987,相关性较好。结论 LC-MS/MS法与循环酶法测定血清中HCY浓度的相关性较好,LC-MS/MS法适用于临床对HCY的检测。     

高通量检测戈谢病和尼曼匹克病A/B型的超高效液相色谱-串联质谱法的建立

目的建立超高效液相色谱-串联质谱(UPLC-MS/MS)技术测定干血滤纸片中酸性葡萄糖脑苷脂酶(ABG)和酸性鞘磷脂酶(ASM)活性的方法。方法将干血滤纸片样本提取液与酶作用底物和内标的混合溶液孵育过夜,反应液经萃取、氮气吹干及复溶后采用UPLC-MS/MS检测产物浓度及内标,计算酶活性。评价该方法的线性、精密度和准确性。结果 UPLC-MS/MS测定ABG和ASM活性的批内、批间精密度为3.6%~8.4%,批内、批间准确度为101%~115%。正常新生儿中ABG和ASM活性呈偏态分布(P0.01),以第0.5~99.5百分位数法确定ABG及ASM活性的参考区间分别为5.52~49.50和2.02~15.44μmol·L~(-1)·h~(-1)。经临床验证,UPLC-MS/MS能有效检出戈谢病(GD)或尼曼匹克病A/B型(NPA/B)患儿,检出率为100%。结论UPLC-MS/MS能同时测定干血滤纸片中ABG、ASM活性。该法快速、特异,可用于新生儿中GD、NPA/B的高通量筛查及临床检测。     

同位素稀释液相色谱-串联质谱法检测血清睾酮候选参考方法的建立及应用

目的建立基于液相色谱串联质谱(LC-MS/MS)技术的血清睾酮候选参考方法,并采用该方法对临床常规检测方法(微粒子化学发光法)的正确性进行评价。方法采用睾酮-2,3,4-~(13)C_3作为内标,以等体积比的正己烷-乙酸乙酯溶液对样本进行液液萃取,上清液采用氮气吹干后用流动相复溶,进行LC-MS/MS分析。采用五点包括法计算血清睾酮浓度。参考美国临床实验室标准化协会(CLSI)C62-A文件和EP15-A3文件对建立的同位素稀释液相色谱-串联质谱(ID-LC-MS/MS)方法进行性能评价(方法残留、特异性、线性范围、精密度、准确度),参考CLSI EP9-A3文件对微粒子化学发光法的正确性进行评价。结果建立的ID-LC-MS/MS方法检测血清睾酮的分析时间为5min,特异性好,无残留,线性范围为0.034～22.00ng/mL,批内不精密度≤2.3%,批间不精密度≤2.2%,测定有证参考物质SRM971(Level male)的相对偏移为0.2%,测定2017 RELA-A、2017 RELA-B样本的相对偏移分别为-2.9%、-3.3%,测定2017 RELA-A样本的不确定度为0.11 ng/mL。微粒子化学发光法与ID-LC-MS/MS的相关性较好(r=0.963),但偏差较大[总平均偏差为-24.4%,低浓度样本(≤1 ng/mL)平均偏差为-62.4%,高浓度样本(1 ng/mL)平均偏差为6.3%]。结论成功建立了检测血清睾酮的ID-LC-MS/MS候选参考方法。该方法的精密度、准确度均较好,且操作简单,分析时间短。     

Development and performance evaluation of a tandem mass spectrometry assay for 4 adrenal steroids

BACKGROUND: Congenital adrenal hyperplasia is a group of autosomal recessive disorders caused by a deficiency of 1 of 4 enzymes required for the synthesis of glucocorticoids, mineralocorticoids, and sex hormones. Analysis of 11-deoxycortisol (11DC), 17-hydroxyprogesterone (17OHP), 17-hydroxypregnenolone (17OHPr), and pregnenolone (Pr) in blood allows detection of these enzyme defects. METHODS: The steroids were extracted from 200 microL of serum or plasma by solid-phase extraction, derivatized to form oximes, and extracted again with methyl t-butyl ether. Instrumental analysis was performed on an API 4000 tandem mass spectrometer with electrospray ionization in positive mode and multiple reaction-monitoring acquisition. RESULTS: The limits of detection were 0.025 microg/L for 11DC, 17OHP, and Pr and 0.10 microg/L for 17OHPr. The method was linear to 100 microg/L for 11DC, 17OHP, and Pr, respectively, and to 40 microg/L for 17OHPr. Within- and between-run (total) imprecision (CVs) were <7.1% and 11%, respectively. Reference intervals for children in Tanner stages 1 through 5 and adult males and females for 17OHP, 11DC, Pr, and 17OHPr were established. Prepared samples were stable for >72 h. CONCLUSIONS: The detection limit and selectivity of this method and its small sample volume requirement allow analysis of endogenous concentrations of adrenal steroids in serum or plasma from children and adults. The method thus has an important potential role in the evaluation of the status of 4 of the enzymes involved in adrenal steroid biosynthesis.     

Circulating androgens and SHBG during the normal menstrual cycle in two ethnic populations

The objective of this study was to study possible ethnic differences in steroid hormones and sex hormone-binding globulin (SHBG) during the menstrual cycle. Serum levels of the ovarian steroids estradiol (E2) and progesterone (P) and of follicle-stimulating hormone (FSH), luteinizing hormone (LH), SHBG, dehydroepiandrosterone (DHEA) and testosterone (T-ria) were all measured by immunoassay during the menstrual cycle in 15 Swedish and 11 West Asian regularly menstruating women. Testosterone (T-ms) was also measured by LC-MS/MS and so were 4-androstene-3,17-dione (A-4) and 17-alpha-hydroxyprogesterone (17-OHP). There were no ethnic differences in levels of ovarian steroids, gonadotrophins, A-4, 17-OHP and T-ms. DHEA were significantly higher and SHBG significantly lower in West Asian than in Swedish women. Surprisingly, T-ria was significantly higher in West Asian than in Swedish women and higher than T-ms (47% in Swedish and 107% in West Asian women). The difference (T-ria???T-ms) showed strong positive correlations to DHEA in the total and in West Asian but not in Swedish women, indicating an influence of DHEA/DHEAS metabolites on the T-ria results. In conclusion, ethnic differences in cross reacting steroids may cause erroneous results in one ethnic group by a steroid immunoassay having reasonable specificity in another. The reasons for the lower SHBG and the higher DHEA levels in West Asian women are not known. The results raise the question about establishing different reference values for certain analytes in different ethnic groups.     

A sensitive and rapid mass spectrometric method for the simultaneous measurement of eight steroid hormones and CALIPER pediatric reference intervals

ObjectivesTo develop an accurate assay and establish the normal reference intervals for serum cortisol, corticosterone, 11-deoxycortisol, androstenedione, 21-hydroxyprogesterone, testosterone, 17-hydroxyprogesterone, and progesterone. These steroids are commonly used as biomarkers for the diagnosis and monitoring of endocrine diseases such as congenital adrenal hyperplasia. Appropriate age- and gender-stratified reference intervals are essential in accurate interpretation of steroid hormone levels.Design and methodsThe samples analyzed in this study were collected from healthy, ethnically diverse children in the Greater Toronto Area as part of the CALIPER program. A total of 337 serum samples from children between the ages of 0 and 18 years were analyzed. The concentrations were measured by using an LC–MS/MS method. The data were analyzed for outliers and age- and gender-specific partitions were established prior to establishing the 2.5th and 97.5th percentiles for the reference intervals.ResultsReference intervals for all hormones required significant age-dependent stratification while testosterone and progesterone required additional sex-dependent stratification.ConclusionsWe report a sensitive, accurate and relatively fast LC–MS/MS method for the simultaneous measurement of eight steroid hormones. Detailed reference intervals partitioned based on both age and gender were also established for all eight steroid hormones.     

Direct solid-phase time-resolved fluoroimmunoassay of 17 alpha-hydroxyprogesterone in serum and dried blood spots on filter paper

We describe a direct, solid-phase time-resolved fluoroimmunoassay (TRFIA) for measuring 17 alpha-hydroxyprogesterone (17OHP) in serum and blood spots on filter paper. We used 17OHP-3-carboxymethyloxime (17OHP3CMO) coupled to polylysine as the label, which enabled incorporation of up to 34 atoms of europium per molecule of 17OHP, for a very high specific activity. The assay is based on competition between labeled 17OHP3CMO and 17OHP in blood specimens for polyclonal rabbit anti-17OHP antibodies. The antibody-label complex is separated by binding to anti-rabbit antibodies coated onto microtiter strips. The assay buffer contains danazol to displace 17OHP from steroid-binding proteins in serum. For serum samples, the assay is accomplished in 1 h of incubation at room temperature. The blood spot assay with filter paper discs involves incubation overnight at 4 degrees C. Results for both types of specimens from the same subjects correlated well. The lowest measurable concentrations of 17OHP (nmol/L) were 0.10 (3 SD) and 0.75 (3 SD) for serum and dried blood on filter paper, respectively. Intra- and interassay CVs were about 5-15% for both types of samples.     

Development and validation of a LC-MS/MS method for the establishment of reference intervals and biological variation for five plasma steroid hormones

BackgroundWith liquid chromatography–tandem mass spectrometry (LC-MS/MS) increasingly being used for the quantification of steroid hormones, there is a need for studies that re-establish reference intervals and biological variation in well-defined cohorts.MethodsA plasma steroid hormone profiling method using LC-MS/MS for quantification of progesterone, 17-hydroxyprogesterone, androstenedione, testosterone and dihydrotestosterone was developed and validated. For reference interval assessment, 280 well-characterized healthy subjects from the LifeLines cohort were selected, including 40 women using oral contraceptive pills (OCP). The biological variation was examined in 30 healthy individuals. Samples were collected over a period of 4 months with 4 week intervals.ResultsThe developed method proved to be robust and sensitive. The reference interval levels in men are higher, whereas in women the levels tend to decrease with increasing age. In addition, women using OCP had lower levels of 17-OH-progesterone and androstenedione. The biological variation is generally higher in women compared to men, especially with regard to the inter-individual variation.ConclusionsThe gender-specific determination of the reference intervals, together with the observation that the biological variation demonstrated a high degree of variation, allows interpretation of data on individual and group level for improved biochemical characterization of patients in clinical practice.     

Pediatric reference intervals for aldosterone, 17α-hydroxyprogesterone, dehydroepiandrosterone, testosterone and 25-hydroxy vitamin D3 using tandem mass spectrometry

Objectives

To determine age and sex-specific pediatric reference intervals for aldosterone, 17α-hydroxyprogesterone, dehydroepiandrosterone, testosterone, and 25-hydroxy vitamin D₃.

Background and design

Reference intervals were determined for neonates and children 0-18 years of age. The study was conducted at both Children's National Medical Center and Georgetown University using outpatient blood samples obtained between January 1, 2004 and June 30, 2008.

Methods

Serum samples were analyzed using isotope dilution liquid chromatography tandem mass spectrometry (LC/MS/MS) with deuterium-labeled internal standards at Children's National Medical Center and Georgetown University Medical Center Bioanalytical Core Laboratory.

Results and conclusions

This is the first study to provide pediatric reference intervals of steroid hormones for children from birth to 18 years of age using LC/MS/MS. Reference intervals were established for aldosterone, 17α-hydroxyprogesterone, dehydroepiandrosterone, testosterone, and 25-hydroxy vitamin D₃. All the analytes exhibited at least some age dependence. Sex differences between early and late childhood and adolescence were found for 17α-hydroxyprogesterone and testosterone. Seasonal differences were apparent for 25-hydroxy vitamin D₃.     

Determination of 17alpha-hydroxyprogesterone in serum by liquid chromatography-tandem mass spectrometry and immunoassay

17Alpha-hydroxyprogesterone (17OHP) is the most important serum marker for congenital adrenal hyperplasia (CAH). 17OHP is usually measured by immunoassay but its detection by mass spectrometry (MS) is a potentially superior method. An LC-MS (liquid chromatography-mass spectrometry) method was developed which utilizes 0.5 ml serum spiked with 6-alpha-methylprednisolone (6-MP) or deuterated 17OHP (d8-IS) as the internal standard. The samples were extracted with ether/ethylacetate, and the extract was evaporated to dryness and analysed by LC-MS/MS operating in the positive mode after separation on a reversed-phase C18 column. The calibration curves for analysis of serum 17OHP exhibited consistent linearity and reproducibility in the range of 5-250 nmol/l. Interassay CVs were 8.5 and 9.2% at mean concentrations of 7.9 and 23 nmol/l, respectively. The detection limit was 1 nmol/l (signal-to-noise ratio=3). The mean recovery of 17OHP added to serum ranged from 76 to 89% and that of internal standards from 75 to 82%. The regression equation for the LC-MS/MS (x) and in-house radioimmunoassay (RIA) (y) methods was: y=0.87x+0.26 (r=0.97; n=100) and for a commercial RIA it was: y=1.32x+0.02 (r=0.97; n=26).     

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

BackgroundDue 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.MethodsThe 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).ResultsThe 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.ConclusionsThe 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.     

Serum dehydroepiandrosterone, dehydroepiandrosterone sulfate, and pregnenolone sulfate concentrations in patients with hyperthyroidism and hypothyroidism

BACKGROUND: Dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEA-S) have been suggested to have protective effects against cardiovascular disease, cancer, immune-modulated diseases, and aging. We examined serum concentrations of DHEA, DHEA-S, and pregnenolone sulfate (PREG-S) in patients with thyroid dysfunction. METHODS: Steroids extracted with methanol from serum sample were separated into an unconjugated fraction (DHEA) and a monosulfate fraction (DHEA-S and PREG-S), using a solid-phase extraction and an ion-exchange column. After separation of unconjugated steroids by HPLC, the DHEA concentration was measured by enzyme immunoassay. The monosulfate fraction was treated with arylsulfatase, and the freed steroids were separated by HPLC. The DHEA and PREG fractions were determined by gas chromatography-mass spectrometry, and the concentrations were converted into those of DHEA-S and PREG-S. RESULTS: Serum concentrations of DHEA, DHEA-S, and PREG-S were all significantly lower in patients with hypothyroidism (n = 24) than in age- and sex-matched healthy controls (n = 43). By contrast, in patients with hyperthyroidism (n = 22), serum DHEA-S and PREG-S concentrations were significantly higher, but the serum DHEA concentration was within the reference interval. Serum concentrations of these three steroids correlated with serum concentrations of thyroid hormones in these patients. Serum albumin and sex hormone-binding globulin concentrations were not related to these changes in the concentration of steroids. CONCLUSIONS: Serum concentrations of DHEA, DHEA-S, and PREG-S were decreased in hypothyroidism, whereas serum DHEA-S and PREG-S concentrations were increased but DHEA was normal in hyperthyroidism. Thyroid hormone may stimulate the synthesis of these steroids, and DHEA sulfotransferase might be increased in hyperthyroidism.     

A fully automated method for sample clean-up prior to chromatographic and immunological analysis

A fully automated technique for the extraction and clean-up of low-molecular weight analytes from human serum and urine is presented. Its efficiency for sample clean-up prior to immunological assay is demonstrated for six adrenal and gonadal steroid hormones, calcidiol and the peptide hormones gastrin, insulin and glucagon. A more intensive sample clean-up, which is mandatory for liquid chromatographic analysis, is reported for serum cortisol. With the exception of calcidiol, the extraction of steroids is almost complete. Recovery of peptides is about 80% and depends on the nature of the peptide and on protein-analyte dissociating diluents. Precision of recovery is lower than 7% (CV) for all analytes studied. One hundred serum or urine samples can be cleaned up without loss of efficiency by only one solid-phase cartridge. The technique is in principle applicable to all other analytes with physico-chemical structures similar to the analytes in the present study.