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In laboratory medicine, external quality assessment (EQA) schemes have become versatile tools for detecting analytical flaws. However, EQA schemes are lacking for pediatric sex steroid levels. We aimed to investigate the suitability of different estradiol and testosterone immunoassays in a pediatric setting in comparison with clinical liquid chromatography-tandem mass spectrometry (LC-MS/MS) assays. The study was conducted by staff and the advisory group on endocrinology at Equalis, the Swedish provider of EQA schemes for laboratory medicine. The test material consisted of five pooled serum samples from children who were either prepubertal or in puberty. Clinical laboratories enrolled in Equalis EQA schemes for estradiol and testosterone were invited to participate, as were clinical laboratories using LC-MS/MS-assays. Samples were analyzed by either routine immunoassays (n=18) or in-house LC-MS/MS assays (n=3). For estradiol, LC-MS/MS assays showed a high degree of conformity with interlaboratory coefficients of variation (CV) below 24.2 %. Reported levels were between 4.9 ± 1.2 and 33.9 ± 1.6 pmol/L (group mean ± standard deviation). The direct immunoassays had lower precision; their CVs were up to 81.4 %. Reported concentrations were between 25.3 ± 18.1 and 45.7 ± 19.4 pmol/L, an overestimation compared to LC-MS/MS. Testosterone LC-MS/MS also showed a high degree of conformity, CVs were below 13.4 %, and reported concentrations were from 0.06 ± 0.00 to 1.00 ± 0.11 nmol/L. The direct immunoassays had a larger discrepancy between results; CVs were up to 95.8 %. Concentrations were between 0.12 ± 0.11 and 0.85 ± 0.23 nmol/L. For the safe diagnosis and determination of sex steroids in children, analysis with mass spectrometry-based methods is recommended. [ABSTRACT FROM AUTHOR]

Background: Boys born small for gestational age (SGA) are at increased risk of testicular dysgenesis syndrome, and girls born SGA face the risk of polycystic ovary syndrome later in life. Our aim was to study whether neonates born SGA have an altered profile of steroid hormones at birth.Materials and methods: A total of 168 singletons (99 boys, 69 girls) born at 32.0-36.9 gestational weeks were recruited to a population-based, university hospital, single-center study. Of these, 31 infants (17 boys, 14 girls) were born SGA. The concentrations of dehydroepiandrosterone sulfate (DHEAS), androstenedione, testosterone, dihydrotestosterone, estrone, estradiol, cortisone, and cortisol were analyzed in umbilical cord serum with mass spectrometry.Results: Girls born SGA had higher levels of androstenedione than girls born appropriate for gestational age (AGA) (4.0 versus 2.6 nmol/L, p = .002). Boys born SGA had lower levels of estrone than boys born AGA (33 822 versus 62 471 pmol/L, p = .038). Infants born SGA had lower levels of cortisone than infants born AGA, both in girls (340 versus 579 nmol/L, p = .010) and in boys (308 versus 521 nmol/L, p = .045). Furthermore, boys born SGA had a higher cortisol/cortisone ratio than boys born AGA (0.41 versus 0.25, p = .028). Gestational age correlated with DHEAS (boys r = 0.48, p = .000, girls r = 0.35, p = .013), and cortisol (boys r = 0.48, p = .000, girls r = 0.29, p = .039).Conclusions: In moderate-to-late preterm infants born SGA, we observed a different steroid hormone profile in cord serum. Girls born SGA show increased levels of androstenedione and boys born SGA show decreased levels of estrone in cord serum, which could be related to placental aromatase deficiency in intrauterine growth restriction. [ABSTRACT FROM AUTHOR]

Quantitation of endogenous steroids and their precursors is essential for diagnosis of a wide range of endocrine disorders. Usually, these analyses have been carried out using immunoassays. However, immunoassays often overestimate concentrations due to assay interference by other endogenous steroids, especially for low concentrations. Mass spectrometry based methods offer superior specificity, accuracy, and sensitivity. We therefore present a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method with automated sample preparation for determination of 17α-hydroxyprogesterone (17OHP), cortisol, cortisone, dehydroepiandrosterone sulfate (DHEAS), androstenedione (A4), testosterone (T), and estrone sulfate (E1S). Samples were prepared using protein precipitation and 96-well filter plates, fully automated in a pipetting robot and analyzed by LC-MS/MS. Serum samples from 187 healthy children and adolescents aged 5-18 years were used to study hormone changes in relation to sex and pubertal stage. Lower limit of quantification for 17OHP was 0.7 nmol/L, for cortisol 11 nmol/L, for cortisone 2 nmol/L, for DHEAS 0.1 µmol/L, and for A4, T, and E1S, 0.2 nmol/L. This study showed a general increase in 17OHP, DHEAS, A4, T and E1S in both genders during puberty. In boys, A4 and T increased significantly throughout pubertal development. Girls had significantly higher A4 and E1S concentrations, while boys had higher T concentrations. No sex- or puberty-specific differences were seen in cortisol or cortisone concentrations. To the best of our knowledge, this is the first presentation of changes in serum E1S concentrations during pubertal development in healthy children. [ABSTRACT FROM AUTHOR]

Highlights • A GC–MS/MS based method for quantification of sex steroids in children is presented. • Adrostenedione, dihydrotestosterone, testosterone, estrone, estradiol were analyzed. • The GC–MS/MS- based method was sensitive enough for use in pediatric applications. • Reference intervals were established in relation to sex and pubertal maturation. Abstract Background Androgen and estrogen determinations serve as important diagnostic markers in a variety of clinical conditions. However, one challenge is to enhance assay sensitivity for determination in the lowest range, such as in prepubertal children. We here present a recently developed gas chromatography–tandem mass spectrometry (GC–MS/MS) method for determination of androstenedione (A 4), dihydrotestosterone (DHT), testosterone (T), estrone (E 1), and estradiol (E 2) in children, which we have compared with the sensitive radioimmunoassays; E 2 extraction-RIA and T-RIA. Methods Steroids were extracted in ethyl acetate n-hexane solution from serum spiked with isotopically labeled internal standard and derivatized sequentially with pentafluorobenzyl bromide, pentafluorobenzyl hydroxylamine and pentafluoropropionic acid anhydride and analyzed by GC–MS/MS using a triple quadrupole mass spectrometer operated in negative chemical ionization mode. Leftover routine samples (n = 414) were used to evaluate the concordance between GC–MS/MS and RIAs and the validity of GC–MS/MS for pediatrics; of these samples, 101 were from seemingly healthy children. Pubertal stage was recorded for reference interval evaluation. Results Lower limit of detection for A 4 , T, DHT, E 1 , and E 2 were 0.1 nmol/L, 0.1 nmol/L, 27 pmol/L, 9 pmol/L, and 2 pmol/L, respectively. Good agreement was found between GC–MS/MS and T-RIA (r = 0.98) as well as between GC–MS/MS and E 2 extraction-RIA (r = 0.98, for E 2 concentrations above 14 pmol/L). In boys, T and DHT increased significantly from prepuberty throughout pubertal development, and in girls the same increase was observed for E 1 and E 2. The greatest increase in A 4 for both genders, as well as E 1 and E 2 in boys and T and DHT in girls, occurred in mid to late puberty. Conclusions We report the development of a GC–MS/MS method sensitive enough to accurately determine serum levels of androgens and estrogens in children. [ABSTRACT FROM AUTHOR]

Aim: We aimed to evaluate aspects of pubertal development to identify the most reliable clinical sign of pubertal onset in males. Methods: We performed a mini review of the literature. Results: In 1951 Reynolds and Wines categorised pubic hair growth and genital development in five stages by visual inspection. Today the Tanner scale is used to assess the five stages of pubertal development, The second genital stage, characterised by enlargement of the scrotum defines pubertal onset in males. Testicular volume may be evaluated by using a calliper or by ultrasound scan. The Prader orchidometer, described in 1966, offers a method for evaluating testicular growth by palpation. Pubertal onset is commonly defined as testicular volume >3 or ≥4 mL. The development of sensitive laboratory methods has enabled studies analysing hormonal activity in the hypothalamus‐pituitary‐gonadal axis. We review the relationships between physical and hormonal signs of puberty. We also discuss the results of studies assessing different aspects of pubertal development with a focus on identifying the most reliable clinical sign of pubertal onset in males. Conclusion: A substantial amount of evidence supports testicular volume of 3 mL as the most reliable clinical sign of male pubertal onset. [ABSTRACT FROM AUTHOR]

Background. Immunoassays have been criticized for poor accuracy at low testosterone concentrations. Mass spectrometry (MS) has been proposed as the only reliable method for testosterone determination. The aim of this study was to compare a sensitive testosterone radioimmunoassay (RIA) with results from different MS. Methods. We compared testosterone concentrations determined by a sensitive testosterone RIA, lower limit of detection 0.03 nmol/L and limit of quantitation 0.1 nmol/L, with four tandem MS that were included in an international external quality assessment program for laboratory medicine. We also compared the morning concentrations of testosterone in girls and boys at different pubertal stages, using results from the RIA, with reported values determined by LC-MS/MS, developed for androgen determination in children. Results. The mean (SD), concentrations were similar between RIA and MS: 1.5 (0.3) and 1.4 (0.4) in the child/women range (0.8-2.6 nmol/L) and 16.0 (3.7) and 17.8 (4.5) nmol/L for the adult male range (10.1-30.0 nmol/L), respectively. The ratio between RIA and MS versus results from mean values of the four MS methods was 1.0 (0.18); 1.1 (0.18) for child/women concentrations and 0.9 (0.13) for male testosterone concentrations. Furthermore, compared to the pediatric reference values determined by LC-MS/MS, the sensitive testosterone RIA delivered similar testosterone values across the different pubertal stages. Conclusions. The comparison between different tandem MS methods and a sensitive testosterone RIA illustrates that there are immunoassays that deliver clinically useful information in prepubertal and pubertal children. [ABSTRACT FROM AUTHOR]

Background/Aim: The goal of estrogen replacement therapy (ERT) in girls with hypogonadism is to achieve the endocrine milieu similar to natural puberty, where transdermal administration is the most physiological route. The aim of the study was to evaluate guidelines for the induction of puberty with transdermal estradiol (E2) patches in a large outpatient setting. Methods: In a retrospective study, serum E2 levels from 18 clinics were analyzed at the Göteborg Pediatric Growth Research Center laboratory, as part of the initiation of ERT in girls with hypogonadism. Exclusion criteria were pubertas tarda and pubertal arrest. Eighty-eight observations (50 with Turner syndrome, TS) were included. Serum E2 levels were determined by extraction + radioimmunoassay (detection limit 4 pmol/l) and analyzed in relation to the dose of Evorel® (25 µg/24 h, containing 1.60 mg estradiol hemihydrate; Janssen-Cilag Pharmaceutica N.V., Beerse, Belgium). Results: There was a linear relationship between serum E2 and the weight-based dose, with r = 0.56, p < 0.0001 for all observations and r = 0.59, p < 0.0001 for the TS study group. Linear regression analysis for doses of 0.05-0.07 µg/kg resulted in serum levels of 17-23 pmol/l (TS 17-24 pmol/l) and doses of 0.08-0.12 µg/kg in 26-39 pmol/l (TS 27-39 pmol/l). Conclusions: For the initiation of ERT with nocturnally administered E2 patches, we recommend reduced starting doses of 0.05-0.07 µg/kg, with the goal of mimicking E2 levels during gonadarche. In older girls, when breast development is of high priority, the starting dose can still be 0.08-0.12 µg/kg. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Aim: To study the influence of growth hormone (GH) treatment on the initiation and progression of puberty in short children. Methods: This prospective, randomized, controlled study included 124 short children (33 girls) who received GH treatment (Genotropin®; Pfizer Inc.) from a mean age of 11 years until near adult height [intent-to-treat (ITT) population]. Children were randomized into three groups: controls (n = 33), GH 33 μg/kg/day (n = 34) or GH 67 μg/kg/day (n = 57). Prepubertal children at study start constituted the per-protocol (PP) population (n = 101). Auxological measurements were made and puberty was staged every 3 months. Serum sex-steroid concentrations were assessed every 6 months. Results: No significant differences were found between the groups, of both PP and ITT populations, in time elapsed from start of treatment until either onset of puberty, age at start of puberty or age at final pubertal maturation in either sex. In the ITT population, pubertal duration was significantly longer in GH-treated girls, and maximum mean testicular volume was significantly greater in GH-treated boys than controls, but there were no differences in testosterone levels between the groups. Conclusion: GH treatment did not influence age at onset of puberty and did not accelerate pubertal development. In boys, GH treatment appeared to increase testicular volume. Copyright © 2011 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: The role of estrogens in male physiology has become evident. However, clinically useful normative data for estradiol secretion in boys has not previously been established due to the insensitivity of current methods used in clinical routine. By use of a validated ultra-sensitive extraction RIA, our aim was to establish normative data from a group consisting of healthy boys in prepuberty and during pubertal development. Methods: Sixty-two 24-hours serum profiles (6 samples/24 hours) were obtained from 44 healthy boys (ages; 7.2-18.6 years) during their pubertal development, classified into five stages: prepuberty (testis, 1-2 mL), early (testis, 3-6 mL), mid (testis, 8-12 mL), late-1 (testis,15-25 mL, not reached final height) and late-2 (testis,15-25 mL, reached final height). Serum estradiol was determined by an ultra- sensitive extraction radioimmunoassay with detection limit 4 pmol/L and functional sensitivity 6 pmol/L. Results: Mean estradiol concentrations during 24-hours secretion increased from prepuberty (median: <4 (5-95 percentiles: <4 - 7) pmol/L) to early puberty (6 (<4 - 12 pmol/L) but then remained relatively constant until a marked increase between mid-puberty (8 (4 - 17) pmol/L) and late-1 (21 (12 - 37) pmol/L) puberty, followed by a slower increase until late-2 puberty (32 (20 - 47) pmol/L). The diurnal rhythm of serum estradiol was non-measurable in pre- and early puberty, but discerned in mid-puberty, and become evident in late pubertal stages with peak values at 0600 to 1000 h. Conclusion: With the use of an ultra-sensitive extraction RIA, we have provided clinically useful normative data for estradiol secretion in boys. [ABSTRACT FROM AUTHOR]

Aim: We investigated longitudinal adrenal androgen concentrations and any relationship between gestational age, birth size, anthropometric parameters and adrenal androgen concentrations during childhood in boys born moderate to late preterm.Methods: This longitudinal, prospective study included 58 boys born at 32+0 to 36+6 weeks of gestation. Dehydroepiandrosterone sulphate and androstenedione were analysed by liquid chromatography-tandem mass spectrometry, and anthropometric data were recorded from 5 to 10 years of age.Results: Dehydroepiandrosterone sulphate concentrations correlated with weight standard deviations scores (SDS) from 7 to 10 years of age and waist-to-height ratios at seven and 10 years of age. Androstenedione correlated with weight SDS from 7 to 10 years of age and waist-to-height ratios at 10 years of age. Longitudinal analysis showed a relationship between weight SDS and waist-to-height SDS and dehydroepiandrosterone sulphate (p < 0.001 and p < 0.001, respectively) and androstenedione (p = 0.002 and p = 0.003, respectively), independently of age.Conclusion: The trajectories of anthropometric parameters and adrenal androgen secretion were consistent from 5 to 10 years of age in this cohort. The body composition reflected by current weight and the waist-to-height ratio, rather than gestational age and birth size, was associated with adrenal androgen secretion. [ABSTRACT FROM AUTHOR]

Background: Most girls with Turner syndrome (TS) require pubertal induction with estrogen, followed by long term replacement. However, no adequately powered prospective studies comparing transdermal with oral 17β-estradiol administration exist. This reflects the difficulty of securing funding to study a rare condition with relatively low morbidity/mortality when competing against conditions such as cancer and vascular disease. Protocol Consensus: The TS Working Group of the European Society for Paediatric Endocrinology (ESPE) has agreed to both a 3-year oral and a 3-year transdermal regimen for pubertal induction. Prerequisites include suitable 17β-estradiol tablets and matrix patches to allow the delivery of incremental doses based on body weight. Study Proposal: An international prospective cohort study with single centre analysis is proposed in which clinicians and families are invited to choose either of the agreed regimens, usually starting at 11 years. We hypothesise that pubertal induction with transdermal estradiol will result in better outcomes for some key parameters. The primary outcome measure chosen is height gain during the induction period. Analysis: Assessment of the demographics and drop-out rates of patients choosing either oral or transdermal preparations; and appropriate analysis of outcomes including pubertal height gain, final height, liver enzyme and lipid profile, adherence/acceptability, cardiovascular health, including systolic and diastolic blood pressure and aortic root diameter and bone health. Conclusion: The proposed model of prospective data collection according to internationally agreed protocols aims to break the current impasse in obtaining evidence-based management for TS and could be applied to other rare paediatric endocrine conditions. [ABSTRACT FROM AUTHOR]

Objective: The relationship between sex hormone concentrations during childhood and birth weight (BW) is poorly understood. We aimed to investigate this relationship and the associations with anthropometric data at 5, 6, 7, 8, and 10 years of age in preterm boys. Design: A prospective longitudinal single‐centre study, including 58 boys with a BW of 1325–3320 g and gestational age (GA) of 32 + 2 to 36 + 6 weeks. Patients and Measurements: Data on GA, BW and anthropometric data between 5 and 10 years of age were recorded. Testicular development was assessed at 8 and 10 years of age. Serum concentrations of sex steroids were analysed with gas chromatography‐tandem mass spectrometry at 5–10 years and luteinizing hormone (LH) and follicle‐stimulating hormone (FSH) with immunoassays at 10 years of age. Results: At 8 years of age, testosterone and estrone correlated negatively with BW, (ρ = −0.35, p =.021) and (ρ = −0.34, p =.024), respectively. At 10 years of age, testosterone, dihydrotestosterone, estrone and estradiol correlated negatively with BW (ρ = −0.39, p =.010), (ρ = −0.38, p =.013), (ρ = −0.44, p =.003) and (ρ = −0.36, p =.019), respectively. Weight gain from birth correlated with testosterone at 5 years (ρ = 0.40, p =.002), 7 years (ρ = 0.30, p =.040), 8 years (ρ = 0.44, p =.003) and 10 years (ρ = 0.40, p =.008) of age. At 10 years of age, testosterone correlated with LH (ρ = 0.42, p =.006) and FSH (ρ = 0.33, p =.033) but not with testicular volume. Conclusions: Lower BW was associated with increased sex steroid concentrations from 8 years of age, independently of clinical signs of puberty. [ABSTRACT FROM AUTHOR]

Interpretations: Our findings suggest that if oestrogen action is inhibited in growing adolescents, adult height will increase. This finding provides a rationale for studies that aim to delay bone maturation in several growth disorders. [ABSTRACT FROM AUTHOR]

Background/Aims: Growth Hormone (GH) dosage in childhood is adjusted for body size, but there is no consensus whether body weight (BW) or body surface area (BSA) should be used. We aimed at comparing the biological effect and cost-effectiveness of GH treatment dosed per m2 BSA in comparison with dosing per kg BW in girls with Turner syndrome (TS). Methods: Serum IGF-I, GH dose, and adult height gain (AHG) from girls participating in two Dutch and five Swedish studies on the efficacy of GH were analyzed, and the cumulative GH dose and costs were calculated for both dose adjustment methods. Additional medication included estrogens (if no spontaneous puberty occurred) and oxandrolone in some studies. Results: At each GH dose, the serum IGF-I standard deviation score remained stable over time after an initial increase after the start of treatment. On a high dose (at 1 m2 equivalent to 0.056-0.067 mg/kg/day), AHG was at least equal on GH dosed per m2 BSA compared with dosing per kg BW. The cumulative dose and cost were significantly lower if the GH dose was adjusted for m2 BSA. Conclusion: Dosing GH per m2 BSA is at least as efficacious as dosing per kg BW, and is more cost-effective. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Summary [ABSTRACT FROM AUTHOR]