Nocturnal Salivary Cortisol Is an Accurate Non-Invasive Test to Assess Endogenous Hypercortisolism in Children with Obesity and a Clinical Phenotype Suspicious for Cushing's Syndrome.

INTRODUCTION: Cushing's syndrome (CS) constitutes one of the most challenging diagnostic assessments for paediatric endocrinologists. The clinical presentation of some children with exogenous obesity overlaps with those observed in hypercortisolism states. Accurate, non-invasive first-line tests are necessary to avoid false-positive results in the obese. We aimed to evaluate the diagnostic accuracy of salivary cortisol to assess endogenous hypercortisolism in children with obesity and clinical overlapping signs of CS. METHODS: Case-control study that included children aged 2-18 years, BMI-SDS ≥2.0 and a follow-up >2 years. Patients were assigned to three categories: group A, features strongly indicative of paediatric CS (growth failure combined with increasing weight); group B, features suggestive of CS (e.g., moon face and striae); and group C, less specific features overlapping with CS (e.g., hypertension, hirsutism, insulin resistance). Children in categories A and B formed the control group. Ten patients with confirmed CS were the case group. All children collected saliva samples on the same day in the morning between 7 and 8:00 a.m. (morning salivary cortisol: mSC) and at 11 p.m. (nocturnal salivary cortisol: nSC). The mSC and nSC results were used to calculate the percentage decrease of cortisol at night (%D). Main outcomes by receiver operating characteristic for nSC and the %D were sensitivity, specificity, positive (P) and negative (N) predictive values (PV) and their corresponding 95% CI. Salivary cortisol was measured by electrochemiluminescence assay (lower limit of quantification: 2.0 nmol/L). RESULTS: 75/112 children met the inclusion criteria, whereas 22/75 children were eligible for the control group. Only controls decreased nSC (median and interquartile range: 2.0 [2.0-2.5] nmol/L) compared to mSC (6.9 [4.8-10.4] nmol/L), p < 0.0001. A cut-off for nSC ≥8 nmol/L confirmed CS within a sensitivity: 1.0 (0.69-1.0), specificity: 1.0 (0.85-1.0), PPV: 1.0 (0.69-0.99), and NPV: 1.0(0.85-0.99), achieving a diagnostic efficiency of 100%. The cut-off obtained for %D was 50%. No child with CS had a %D ≥50%, but 6/22 children in the control group had a %D below the cut-off, resulting in a lower overall diagnostic accuracy of 81% compared to nSC. CONCLUSION: Salivary cortisol at 11 p.m. is an accurate, feasible, and non-invasive first-line test to assess endogenous hypercortisolism in children with obesity and clinical suspicion of CS. The nSC was also useful in showing that the circadian rhythm of cortisol was preserved in children with exogenous obesity. In patients with nSC ≥8.0 nmol/L, other biochemical assessments and imaging studies are needed to further confirm the aetiology.

Case report: Novel SIN3A loss-of-function variant as causative for hypogonadotropic hypogonadism in Witteveen-Kolk syndrome.

Pubertal delay can be due to hypogonadotropic hypogonadism (HH), which may occur in association with anosmia or hyposmia and is known as Kallmann syndrome (OMIM #308700). Recently, hypogonadotropic hypogonadism has been suggested to overlap with Witteveen-Kolk syndrome (WITKOS, OMIM #613406) associated with 15q24 microdeletions encompassing SIN3A. Whether hypogonadotropic hypogonadism is due to haploinsufficiency of SIN3A or any of the other eight genes present in 15q24 is not known. We report the case of a female patient with delayed puberty associated with intellectual disability, behavior problems, dysmorphic facial features, and short stature, at the age of 14 years. Clinical, laboratory, and imaging assessments confirmed the diagnosis of Kallmann syndrome. Whole-exome sequencing identified a novel heterozygous frameshift variant, NM_001145358.2:c.3045_3046dup, NP_001138830.1:p.(Ile1016Argfs*6) in SIN3A, classified as pathogenic according to the American College of Medical Genetics and Genomics (ACMG/AMP) criteria. Reverse phenotyping led to the clinical diagnosis of WITKOS. No other variant was found in the 96 genes potentially related to hypogonadotropic hypogonadism. The analysis of the other contiguous seven genes to SIN3A in 15q24 did not reveal any clinically relevant variant. In conclusion, these findings point to SIN3A as the gene in 15q24 related to the reproductive phenotype in patients with overlapping WITKOS and Kallmann syndrome.

Prevalence of Polycystic Ovarian Syndrome in Girls with a History of Idiopathic Central Precocious Puberty.

INTRODUCTION: The prevalence of polycystic ovarian syndrome (PCOS) in adolescent girls is between 1 and 4.3%. It remains controversial whether women with a history of idiopathic central precocious puberty (ICPP) are at increased risk for PCOS. Our objective was to assess the prevalence of PCOS in adolescents with a history of ICPP compared with healthy adolescents and the prevalence of PCOS among ICPP girls who have received or not gonadotropin-releasing hormone analogue (GnRHa) treatment. METHODS: We assessed post-menarcheal girls with a history of ICPP. Girls were evaluated at gynecological age ≥2.5 years. Data collected were age at menarche, menstrual cycle characteristics, BMI, clinical hyperandrogenism (HA), total and free testosterone levels. PCOS diagnosis was defined by criteria for adolescents. Subjects were also analyzed regarding whether or not they had received GnRHa treatment. RESULTS: Ninety-four subjects were assessed, and 63 had been treated with GnRHa. Menstrual disorders were found in 29%, clinical HA in 36%, and biochemical HA in 23%. Twelve percent met the diagnostic criteria for PCOS. There was no difference in BMI or in the incidence of menstrual dysfunction or hyperandrogenemia between treated and untreated patients. A higher proportion of clinical HA was found in untreated patients when compared to treated girls. The relative risk (RR) of developing PCOS in ICPP girls was 2.5 compared to a population of healthy adolescents. This RR was not higher in patients who received treatment with GnRHa than in those who did not. CONCLUSION: Adolescent girls with a history of ICPP have an increased risk of PCOS. This risk seems not to be related to GnRHa treatment.

Diagnostic Accuracy of Morning Salivary Cortisol in the Assessment of the Hypothalamic-Pituitary-Adrenal Axis Recovery after Prolonged Corticosteroid Therapy in Children.

INTRODUCTION: Assessment of the hypothalamic-pituitary-adrenal (HPA) axis is necessary after prolonged glucocorticoid therapy withdrawal. Salivary cortisol reflects 65% of the free circulating cortisol fraction. Saliva collection is non-invasive and child friendly. OBJECTIVE: We aimed to evaluate the diagnostic accuracy of morning salivary cortisol (mSAF) to determine HPA recovery after prolonged corticosteroid therapy in children. METHODS: We conducted a prospective, validation study in 171 paediatric patients (mean ± SD age: 13.0 ± 4.4 years) who received glucocorticoids for >4 weeks (median and interquartile range: 11 [7-14] months) and were referred for therapy withdrawal. Serum and saliva samples were collected between 8 and 9 a.m. on the same day. Cortisol was measured by an electrochemiluminescence immunoassay (ECLIA) 48 h after cessation of glucocorticoid therapy. Serum cortisol ≥193 nmol/L was used as the reference cut-off value for HPA recovery after glucocorticoid withdrawal and mSAF as the index test. RESULTS: The cut-off concentration obtained by ROC for mSAF was ≥5.0 nmol/L. True positive and true negative results were observed in 85/171 and 40/171 children, respectively. The false-positive rate was low (3/171, 1.7%); however, false-negative results were observed in 43/171 (25%) children. The main ROC results (95% CI) were area under curve: 0.98 (0.96-0.99), sensitivity: 0.66 (0.57-0.75), specificity: 0.93 (0.81-0.99), positive predictive value: 0.97 (0.90-0.99), negative predictive value: 0.48 (0.37-0.59), LR+: 9.5, and diagnostic accuracy: 73.1%. CONCLUSION: The present study supports that mSAF ≥5.0 nmol/L by ECLIA is a non-invasive biomarker for the assessment of HPA recovery after prolonged glucocorticoid therapy in paediatric patients, with a positive predictive value of 97%. This proposed cut-off should be further validated using gold standard techniques for steroid quantification such as liquid chromatography-tandem mass spectrometry.

Identification of a Novel Variant in Myelin Regulatory Growth Factor by Next-Generation Sequencing Led to the Detection of a Clinically Inapparent Congenital Heart Defect in a Patient with a 46,XY Disorder of Sex Development.

In patients with 46,XY disorders of sex development (DSDs), next-generation sequencing (NGS) has high diagnostic efficiency. One contribution to this diagnostic approach is the possibility of applying reverse phenotyping when a variant in a gene associated with multiple organ hits is found. Our aim is to report a case of a patient with 46,XY DSDs in whom the identification of a novel variant in MYRF led to the detection of a clinically inapparent congenital heart defect. A full-term newborn presented with ambiguous genitalia, as follows: a 2 cm phallus, penoscrotal hypospadias, partially fused labioscrotal folds, an anogenital distance of 1.2 cm, and non-palpable gonads. The karyotype was 46,XY, serum testosterone and AMH were low, whereas LH and FSH were high, leading to the diagnosis of dysgenetic DSD. Whole exome sequencing identified a novel, heterozygous, nonsense variant in MYRF, classified as pathogenic according to the ACMG criteria. MYRF encodes a membrane-bound transcriptional factor expressed in several tissues associated with OCUGS syndrome (ophthalmic, cardiac, and urogenital anomalies). In the patient, oriented clinical assessment ruled out ophthalmic defects, but ultrasonography confirmed meso/dextrocardia. We report a novel MYRF variant in a patient with 46,XY DSDs, allowing us to identify a clinically inapparent congenital heart defect by reverse phenotyping.

Testicular dysfunction at diagnosis in children and teenagers with haematopoietic malignancies improves after initial chemotherapy.

Introduction: Hematopoietic malignancies are the most frequent type of cancer in childhood. Recent advances in cancer treatment have significantly improved survival until adulthood. There is an extensive literature on the effects of cancer treatment on the gonadal axis in adult survivors of childhood cancer mainly focused on sperm production, but scarce information exists on the immediate impact of cancer and its treatment in boys. Objectives: In this work, we determined the status of the hypothalamic-pituitary-testicular (HPT) axis function at diagnosis and the immediate impact of chemotherapy at the start of treatment in children and adolescents with hematopoietic malignancies. Subjects and methods: In a prospective study of 94 boys and adolescents with acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML) or non-Hodgkin lymphoma (NHL), we determined serum AMH, inhibin B and FSH to assess the gonadotrophin-Sertoli cell component of the HPT axis, and testosterone and LH to evaluate the gonadotrophin-Leydig cell component, at diagnosis and after 3 months of chemotherapy. Secondarily, the general health state was evaluated. Results: In prepubertal boys, at diagnosis, AMH, inhibin B and FSH were lower compared to the reference population, reflecting an FSH-Sertoli cell axis dysfunction. After 3 months of chemotherapy, all hormone concentrations increased. At pubertal age, at diagnosis, AMH and inhibin B were lower compared to the reference population for Tanner stage, with inappropriately normal FSH, suggesting a primary Sertoli cell dysfunction with insufficient gonadotrophin compensation. The LH-Leydig cell axis was mildly disrupted. After 3 months of chemotherapy, inhibin B and AMH were unchanged while median FSH levels rose to values that exceeded the reference range, indicating a significant impairment of Sertoli cell function. Testosterone normalized concomitantly with an abnormal LH elevation reflecting a compensated Leydig cell impairment. General health biomarkers were impaired at diagnosis and improved after 3 months. Conclusion: The HPT axis function is impaired in boys with hematopoietic malignancies before the initiation of chemotherapy. There is a primary testicular dysfunction and a concomitant functional central hypogonadism that could be due to an impaired overall health. The HPT axis function improves during the initial 3 months of chemotherapy concomitantly with the general health state. However, in pubertal boys the dysfunction persists as shown by elevated gonadotropin levels after 3 months.

Delayed Puberty Due to a WDR11 Truncation at Its N-Terminal Domain Leading to a Mild Form of Ciliopathy Presenting With Dissociated Central Hypogonadism: Case Report.

Pubertal delay in males is frequently due to constitutional delay of growth and puberty, but pathologic hypogonadism should be considered. After general illnesses and primary testicular failure are ruled out, the main differential diagnosis is central (or hypogonadotropic) hypogonadism, resulting from a defective function of the gonadotropin-releasing hormone (GnRH)/gonadotropin axis. Ciliopathies arising from defects in non-motile cilia are responsible for developmental disorders affecting the sense organs and the reproductive system. WDR11-mediated signaling in non-motile cilia is critical for fetal development of GnRH neurons. Only missense variants of WDR11 have been reported to date in patients with central hypogonadism, suggesting that nonsense variants could lead to more complex phenotypes. We report the case of a male patient presenting with delayed puberty due to Kallmann syndrome (central hypogonadism associated with hyposmia) in whom the next-generation sequencing analysis identified a novel heterozygous base duplication, leading to a frameshift and a stop codon in the N-terminal region of WDR11. The variant was predicted to undergo nonsense-mediated decay and classified as probably pathogenic following the American College of Medical Genetics and Genomics (ACMG) criteria. This is the first report of a variant in the WDR11 N-terminal region predicted to lead to complete expression loss that, contrary to expectations, led to a mild form of ciliopathy resulting in isolated Kallmann syndrome.

Diagnosis of Male Central Hypogonadism During Childhood.

The diagnosis of male central (or hypogonadotropic) hypogonadism, typically based on low luteinizing hormone (LH) and testosterone levels, is challenging during childhood since both hormones are physiologically low from the sixth month until the onset of puberty. Conversely, follicle-stimulating hormone (FSH) and anti-Müllerian hormone (AMH), which show higher circulating levels during infancy and childhood, are not used as biomarkers for the condition. We report the case of a 7-year-old boy with a history of bilateral cryptorchidism who showed repeatedly low FSH and AMH serum levels during prepuberty. Unfortunately, the diagnosis could not be ascertained until he presented with delayed puberty at the age of 14 years. A gonadotropin-releasing hormone (GnRH) test showed impaired LH and FSH response. By then, his growth and bone mineralization were partially impaired. Gene panel sequencing identified a variant in exon 15 of FGFR1, affecting the tyrosine kinase domain of the receptor, involved in GnRH neuron migration and olfactory bulb morphogenesis. Testosterone replacement was started, which resulted in the development of secondary sexual characteristics and partial improvement of bone mineral density. This case illustrates the difficulty in making the diagnosis of central hypogonadism in boys during childhood based on classical criteria, and how serum FSH and AMH assessment may be helpful if it is suspected before the age of puberty, and confirm it using next-generation sequencing. The possibility of making an early diagnosis of central hypogonadism may be useful for a timely start of hormone replacement therapy, and to avoid delays that could affect growth and bone health as well as psychosocial adjustment.

Development and Validation of a Prediction Rule for Growth Hormone Deficiency Without Need for Pharmacological Stimulation Tests in Children With Risk Factors.

Introduction: Practice guidelines cannot recommend establishing a diagnosis of growth hormone deficiency (GHD) without performing growth hormone stimulation tests (GHST) in children with risk factors, due to the lack of sufficient evidence. Objective: Our goal was to generate an evidence-based prediction rule to diagnose GHD in children with growth failure and clinically identifiable risk factors. Methods: We studied a cohort of children with growth failure to build the prediction model, and a second, independent cohort to validate the prediction rule. To this end, we assessed the existence of: pituitary dysgenesis, midline abnormalities, (supra)sellar tumor/surgery, CNS infection, traumatic brain injury, cranial radiotherapy, chemotherapy, genetic GHD, pituitary hormone deficiencies, and neonatal hypoglycemia, cholestasis, or hypogenitalism. Selection of variables for model building was performed using artificial intelligence protocols. Specificity of the prediction rule was the main outcome measure in the validation set. Results: In the first cohort (n=770), the resulting prediction rule stated that a patient would have GHD if (s)he had: pituitary dysgenesis, or two or more anterior pituitary deficiencies, or one anterior pituitary deficiency plus: neonatal hypoglycemia or hypogenitalism, or diabetes insipidus, or midline abnormalities, or (supra)sellar tumor/surgery, or cranial radiotherapy ≥18 Gy. In the validation cohort (n=161), the specificity of the prediction rule was 99.2% (95% CI: 95.6-100%). Conclusions: This clinical rule predicts the existence of GHD with high specificity in children with growth disorders and clinically identifiable risk factors, thus providing compelling evidence to recommend that GHD can be safely diagnosed without recurring to GHST in neonates and children with growth failure and specific comorbidities.

Safety of standardised treatments for haematologic malignancies as regards to testicular endocrine function in children and teenagers.

STUDY QUESTION: Does standardised treatments used in children and adolescents with haematologic malignancies, including acute lymphoblastic (ALL) or myeloid leukaemia (AML) and non-Hodgkin lymphoma (NHL), affect endocrine function of the developing testes? SUMMARY ANSWER: Therapy of haematologic malignancies do not provoke an overt damage of Sertoli and Leydig cell populations, as revealed by normal levels of anti-Müllerian hormone (AMH) and testosterone, but a mild primary testicular dysfunction may be observed, compensated by moderate gonadotropin elevation, during pubertal development. WHAT IS KNOWN ALREADY: Evidence exists on the deleterious effect that chemotherapy and radiotherapy have on germ cells, and some attention has been given to the effects on Leydig and Sertoli cells of the adult gonads, but information is virtually non-existent on the effects of oncologic treatment on testicular somatic cell components during childhood and adolescence. STUDY DESIGN, SIZE, DURATION: A retrospective, analytical, observational study included 97 boys with haematological malignancies followed at two tertiary paediatric public hospitals in Buenos Aires, Argentina, between 2002 and 2015. PARTICIPANTS/MATERIALS, SETTING, METHODS: Clinical records of males aged 1-18 years, referred with the diagnoses of ALL, AML or NHL for the assessment of gonadal function, were eligible. We assessed serum levels of AMH and FSH as biomarkers of Sertoli cell endocrine function and testosterone and LH as biomarkers of Leydig cell function. MAIN RESULTS AND THE ROLE OF CHANCE: All hormone levels were normal in the large majority of patients until early pubertal development. From Tanner stage G3 onwards, while serum AMH and testosterone kept within the normal ranges, gonadotropins reached mildly to moderately elevated values in up to 35.9% of the cases, indicating a compensated Sertoli and/or Leydig cell dysfunction, which generally did not require hormone replacement therapy. LIMITATIONS, REASONS FOR CAUTION: Serum inhibin B determination and semen analysis were not available for most patients; therefore, we could not conclude on potential fertility impairment or identify whether primary Sertoli cell dysfunction resulted in secondary depleted spermatogenesis or whether primary germ cell damage impacted Sertoli cell function. WIDER IMPLICATIONS OF THE FINDINGS: The regimens used in the treatment of boys and adolescents with ALL, AML or NHL in the past two decades seem relatively safe for endocrine testicular function; nonetheless, a mild primary testicular endocrine dysfunction may be observed, usually compensated by slightly elevated gonadotropin secretion by the pituitary in adolescents, and not requiring hormone replacement therapy. No clinically relevant risk factor, such as severity of the disease or treatment protocol, could be identified in association with the compensated endocrine dysfunction. STUDY FUNDING/COMPETING INTEREST(S): This work was partially funded by grants PIP 11220130100687 of Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) and PICT 2016-0993 of Fondo para la Investigación Científica y Tecnológica (FONCYT), Argentina. R.A.R., R.P.G. and P.B. have received honoraria from CONICET (Argentina) for technology services using the AMH ELISA. L.A.A. is part-time employee of CSL Behring Argentina. The other authors have no conflicts of interest to disclose.

A homozygous mutation in the highly conserved Tyr60 of the mature IGF1 peptide broadens the spectrum of IGF1 deficiency.

BACKGROUND: IGF1 is a key factor in fetal and postnatal growth. To date, only three homozygous IGF1 gene defects leading to complete or partial loss of IGF1 activity have been reported in three short patients born small for gestational age. We describe the fourth patient with severe short stature presenting a novel homozygous IGF1 gene mutation. RESULTS: We report a boy born from consanguineous parents at 40 weeks of gestational age with intrauterine growth restriction and severe postnatal growth failure. Physical examination revealed proportionate short stature, microcephaly, facial dysmorphism, bilateral sensorineural deafness and mild global developmental delay. Basal growth hormone (GH) fluctuated from 0.2 to 29 ng/mL, while IGF1 levels ranged from -1.15 to 2.95 SDS. IGFBP3 was normal-high. SNP array delimited chromosomal regions of homozygosity, including 12q23.2 where IGF1 is located. IGF1 screening by HRM revealed a homozygous missense variant NM_000618.4(IGF1):c.322T>C, p.(Tyr108His). The change of the highly conserved Tyr60 in the mature IGF1 peptide was consistently predicted as pathogenic by multiple bioinformatic tools. Tyr60 has been described to be critical for IGF1 interaction with type 1 IGF receptor (IGF1R). In vitro, HEK293T cells showed a marked reduction of IGF1R phosphorylation after stimulation with serum from the patient as compared to sera from age-matched controls. Mutant IGF1 was also less efficient in inducing cell growth. CONCLUSION: The present report broadens the spectrum of clinical and biochemical presentation of homozygous IGF1 defects and underscores the variability these patients may present depending on the IGF/IGF1R pathway activity.

Aplicación de Hibridación In Situ Fluorescente (FISH) en pacientes con sospecha clínica de Síndrome de Deleción 22q11. 2 (SD22q11. 2) / Applying Fluorescent in situ hy-bridiza on (FISH) in patients with suspected clinical signs of 22q11. 2 dele on syndrome (DS22q11. 2)

El SD22q11.2 está asociado a síndromes de DiGeorge, velocardiofacial, facioconotruncal y Cayler, reconocidos con la misma etiología: microdeleción 22q11.2. El fenotipo es variable y presenta cardiopatía conotruncal (CC), dismorfias faciales, anomalías palatinas, inmunodeficiencias y trastornos del neurodesarrollo. Las manifestaciones endocrinológicas que predominan son talla baja, hipocalcemia neonatal asociada a hipoparatiroidismo y disfunción tiroidea. El 90% de los afectados presenta una deleción típica de 3-Mb, mientras que el resto tiene deleciones de menor tamaño o deleción localizada más distal a la región crítica . El objetivo del trabajo es identificar en una cohorte de 63 pacientes con sospecha clínica de SD22q11.2, la presencia de la microdeleción 22q11.2 empleando como método diagnóstico la técnica de FISH y describir brevemente las características clínicas más prevalentes que presentan los pacientes con resultado de FISH positivo y negativo. La microdeleción 22q11.2 se identificó en el 38% (24/63) de los pacientes estudiados. Las características clínicas más prevalentes en este grupo fueron las cardiopatías congénitas conotruncales (95,6%), microcefalia (50%), inmunodeficiencias (50%), hipocalcemia (48,8%), anomalías del paladar (45,8%), retraso del desarrollo y déficit cognitivo (41,5%). En nuestro hospital, el algoritmo diagnóstico para la detección de la microdeleción 22q11.2 es el cariotipo de alta resolución y el estudio por la técnica de FISH.

DS22q11.2 is associated with a wide spectrum of clinical disorders (DiGeorge, velocardiofacial, facioconotrunal and Cayler syndromes) known to arise from the same etiology 22q11.2 microdeletion The phenotype is variable and includes conotruncal cardiac defect (CCD), facial phenotype, palate anomalies, inmunodeficiency and developmental disorders. The endocrine manifestations are short stature (ST), neonatal hypocalcemia due to hypoparathyroidism, and thyroid dysfunction. In 90% of patients with 22q11.1 deletion a common 3-Mb deletion has been found, whereas the rest of cases share a smaller deletion or more distal atypical deletions. The aim of the present study was to identify the 22q11.2 microdeletion by FISH in 63 patients from the Genetic and Endocrinology Division between 2002 and 2017 who had more than one clinical feature of DS22q11. 2. High resolution karyotype and fluorescent in situ hybridization (FISH) were performed with different commercial probes. The 22q11.2 microdeletion was demonstrated in 24/63 patients (38%). The more relevant clinical features in this group were: conotruncal cardiac defect (95.6%), microcephaly (50%), immunodeficiency (50%), hypocalcaemia (48.8%) palate anomalies (45.8%), development delay and cognitive deficit (41.5%). In our hospital, the diagnostic algorithm for the detection of the 22q11.2 microdeletion is the high resolution karyotype and the study by the FISH technique.

Sistema de la hormona de crecimiento y factores de crecimiento en niños y adolescentes / Growth hormone and growth factors system in children and adolescents

El crecimiento y la maduración física del niño y del adolescente transcurre por diversas etapas observándose cambios en la talla y velocidad de crecimiento característicos que son consecuencia entre otros factores, de cambios hormonales en el sistema o eje de la hormona de crecimiento (GH). Los principales componentes de este eje con utilidad clínica en la etapa infanto-juvenil son la GH, el factor de crecimiento insulino símil tipo I (IGF-I) y las proteínas de transporte. La GH es secretada por la hipófisis en forma de pulsos a la circulación y esto es uno de los principales factores que condicionan su utilidad como marcador de deficiencia de GH. La medición de GH en condiciones basales únicamente tiene valor diagnóstico cuando se obtiene en hipoglucemia y especialmente si se trata de un neonato. Es necesario entonces, en el resto de los casos, evaluar la capacidad de secreción de GH mediante pruebas funcionales de estímulo estandarizadas. Los factores dependientes de GH son considerados biomarcadores fidedignos de la acción de GH. Sin embargo, su concentración varía ampliamente durante la etapa pediátrica obligando su interpretación en el contexto de valores de referencia establecidos según la edad, sexo y desarrollo puberal. El presente trabajo revela los profundos cambios fisiológicos en los componentes del sistema de la GH que ocurren en la etapa pediátrica y los recaudos que deben tenerse en cuenta cuando se utilizan en el diagnóstico de la deficiencia de GH

Among other factors, the postnatal growth and physical maturation of children and adolescents (characterized by changes in the size and growth velocity rates) are influenced by components of the growth hormone (GH) system. GH, the type I insulin-like growth factor (IGF-I) and their transport proteins constitute the more relevant biochemical tools for the GH deficiency (GHD) diagnosis in pediatrics. The GH is secreted by the pituitary gland into the circulation in pulses and this pulsatility limits its usefulness, with the exception of a random basal GH in neonates under hypoglycaemia. Therefore, it is necessary to evaluate GH secretion status in standardized functional tests. IGF-I and IGFBP-3 are considered reliable biomarkers of GH action. However, these GH-dependant biomarkers widely vary in the paediatric period, forcing their interpretation in the context of confident reference values according to age, sex and pubertal development. The present revision reveals the profound physiological changes in the components of the GH system throughout the whole pediatric period and the situations that must be taken into account when they are used in the diagnosis of GHD

Síndrome de Ovario Poliquístico (SOP) en la adolescencia / Polycystic Ovary Syndrome (PCOS) during adolescence

El síndrome de poliquistosis ovárica (SOP) es un cuadro que acompaña a la mujer durante toda su vida y se caracteriza por hiperandrogenismo y anovulación crónica. Se presenta comúnmente en la adolescencia y es eldesorden endócrino más frecuente en mujeres en edad reproductiva en el mundo. A largo plazo se asocia con morbilidad significativa que incluye alteraciones en la salud reproductiva, disfunción psicosocial, síndrome metabólico, enfermedad cardiovascular e incremento en el riesgo de cáncer. Su etiología es desconocida aún, sin embargo, a lo largo de las tres últimas décadas, diferentes grupos de expertos en el mundo han elaborado guías para el diagnóstico y manejo de esta enfermedad. Existen tres grupos diferentes de criterios en el mundo pero están basados principalmente en información y experiencia en el manejo de mujeres adultas. Estos criterios diagnósticos no son completamente trasladables a las adolescentes. El objetivo de este artículo es acercar al pediatra clínico los elementos para alcanzar un entendimiento práctico y simplificar el manejo inicial del diagnóstico del cuadro de SOP en la adolescencia, concientizar acerca de las comorbilidades asociadas y su posibilidad de prevención para evitar riesgos en la vida adulta.

The polycystic ovarian syndrome (PCOS) is a lifelong disorder characterized by hyperandrogenism and chronicanovulation. It becomes manifest soon after puberty and it is the most frequent endocrine disorder in women at reproductive age in the world. In the long term it is associated with significant morbidity that includes alterations in reproductive health, psychosocial dysfunction, metabolic syndrome, cardiovascular disease and increased risk of cancer. Its etiology is still unknown, however, over the last three decades; several guidelines for the diagnosis and management of this disease have been developed. Three different sets of diagnostic criteria have been established to define this disease in adult women, but these diagnostic criteria are not completely transferable to adolescents. The objective of this article is to give pediatricians the elements for a practical understanding to simplify the initial management of the diagnosis of PCOS in adolescence and to raise awareness on the likelihood of associated comorbidities and that appropriate intervention could prevent later complications in adult life

Circulating IGF-I, IGFBP-3 and the IGF-I/IGFBP-3 Molar Ratio Concentration and Height Outcome in Prepubertal Short Children on rhGH Treatment over Two Years of Therapy.

OBJECTIVE: To investigate the occurrence of abnormally elevated values of biomarkers of growth hormone (GH) action in short children on recombinant human GH (rhGH) therapy. METHODS: Sixty-three prepubertal short children were examined: 31 with GH deficiency (GHD), 25 small for gestational age (SGA), and 9 with Turner syndrome (TS). The main outcomes were the following: standard deviation score (SDS) values of IGF-I, IGFBP-3, and IGF-I/IGFBP-3 molar ratio before, at the 1st and at the 2nd year on rhGH and Δheight (Ht)-SDS to evaluate GH treatment efficacy (adequate 1st-year ΔHt SDS: >0.4 SDS for GHD and >0.3 SDS for non-GHD). RESULTS: Seventy-eight percent of GHD, 78% of SGA and 55% of TS children had adequate 1st-year ΔHt SDS. In GHD, 88% of IGF-I SDS and IGFBP-3 SDS that were ≤-2.0 SDS at baseline normalized on treatment. Abnormal IGF-I values >+2.0 SDS were observed in 52% of SGA and in 55% of TS patients on rhGH. Within each group, the IGF-I/IGFBP-3 molar ratio increased significantly from pretreatment and throughout therapy, remaining within normal range for most patients. ΔIGF-I/IGFBP-3 molar ratio SDS were significantly higher in children with an adequate response (p < 0.01). CONCLUSION: Non-GHD groups presented markedly elevated concentrations of GH biomarkers on rhGH and normal IGF-I/IGFBP-3 molar ratio in most patients. Since there is a lack of consensus regarding the molar ratio usefulness, we think that interventions towards a more physiological IGF-I serum profile should be implemented.

Prospective and Descriptive Study on Serum Androstenedione Concentration in Healthy Children from Birth until 18 Years of Age and Its Associated Factors.

INTRODUCTION: Androstenedione (A4) is an adrenal and gonadal steroid biomarker, useful in the assessment of children in whom steroidogenic disorders are suspected. The first key step in the evaluation of a diagnostic test resides on confident reference intervals (RI). The lack of updated A4-RI with current methods in pediatrics may mislead A4 results and limit its diagnosis accuracy. AIM: To provide A4 reference ranges in healthy children. METHODS: Prospective, descriptive study. 283 children aged 4 days to 18 years were included. In children < 1 yr, A4 was measured directly in serum (NE-A4) and postorganic solvent extraction (E-A4) for the assessment of interfering steroids. The influence of chronological age (CA), gender, and Tanner stage (T) were investigated. RESULTS: In the neonatal period, E-A4 was significantly lower than NE-A4; boys had higher NE-A4; sexual dimorphism disappeared after extraction procedure. In children older than 4 months, A4 concentration remained low until the age of 5 years. Thereafter, A4 increased significantly in association with CA and T (r2 = 0.65; p < 0.001), obtaining the highest concentrations in children within pubertal ages without sexual dimorphism. CONCLUSION: We recommend to perform solvent extraction in neonates and to take into account age and sexual development to properly interpret A4 results in childhood.

Assessment of Estradiol Response after Depot Triptorelin Administration in Girls with Central Precocious Puberty.

BACKGROUND: Estradiol at baseline or after a classical gonadotropin-releasing hormone test did not reflect ovarian steroidogenesis in central precocious puberty (CPP) girls. AIMS: To evaluate estradiol response to depot triptorelin, both at start and during therapy to determine how active ovarian steroidogenesis is at pubertal stage and under therapy. METHODS: A prospective study was performed in 43 CPP girls. Serum luteinizing hormone and follicle-stimulating hormone at 3 h (LH-3h, FSH-3h) and estradiol at 24 h (E2-24h) after injection of depot triptorelin 3.75 mg were measured, at first dose and at 3, 6, 12, 18 and 24 months of treatment. RESULTS: E2-24h after depot triptorelin was >100 pg/ml after the first dose. Estradiol response (E2-24h) fell to levels <14 pg/ml in 78 out of 82 follow-up visits along 2 years of therapy. Concomitantly, LH-3h and FSH-3h were <4.0 and <6.3 IU/l, respectively. In 4 patients with inadequate treatment, E2-24h, LH-3h and FSH-3h rose to pubertal values similar to those observed at first dose. CONCLUSION: Estradiol (<14 pg/ml) assessment 24 h after depot triptorelin administration is a reliable and simple manner to confirm ovarian suppression in CPP girls during treatment.

Hypogonadotropic Hypogonadism in Infants with Congenital Hypopituitarism: A Challenge to Diagnose at an Early Stage.

BACKGROUND: Combined pituitary hormone deficiency (CPHD) presents a wide spectrum of pituitary gland disorders. The postnatal gonadotropic surge provides a useful period to explore the gonadotropic axis for assessing the presence of congenital hypogonadotropic hypogonadism (CHH). AIM: To explore the functioning of the hypothalamic-pituitary-gonadal axis in the postnatal gonadotropic surge for an early diagnosis of CHH in newborns or infants suspected of having CPHD. SUBJECTS AND METHODS: A cohort of 27 boys under 6 months and 19 girls under 24 months of age with suspected hypopituitarism was studied. Serum concentrations of LH, FSH, testosterone, inhibin B, anti-Müllerian hormone (AMH) and estradiol were measured, and male external genitalia were characterized as normal or abnormal (micropenis, microorchidism and/or cryptorchidism). RESULTS: CPHD was confirmed in 36 out of 46 patients. Low LH and testosterone levels were found in 66% of the hypopituitary males, in significant association with the presence of abnormal external genitalia. This abnormality had a positive predictive value of 93% for CHH. No significant association was observed between serum FSH, AMH and inhibin B and the patient's external genitalia. CONCLUSION: In newborn or infant boys with CPHD, LH and testosterone concentrations measured throughout the postnatal gonadotropic surge, together with a detailed evaluation of the external genital phenotype, facilitate the diagnosis of CHH at an early stage.

Predicting hypocalcemia after thyroidectomy in children.

BACKGROUND AND AIMS: Hypocalcemia after thyroidectomy is caused by parathyroid trauma. There are no studies regarding the usefulness of intact parathyroid hormone (PTH) as a monitor of postoperative hypoparathyroidism tool in pediatrics. We evaluated the diagnostic accuracy of intra- and postoperative PTH to predict the risk of developing post thyroidectomy hypocalcemia in children. METHODS: A prospective longitudinal cohort study was conducted in 32 pediatric patients (3.2-17.6 years old) undergoing total thyroidectomy. Intact PTH measured by the assays (Immulite Immunoassay System [ICMA] or electrochemioluminescence assay [ECLIA]) at 5 (PTH-5) and 60 (PTH-60) minutes after thyroid removal were considered as predicting variables. The postoperative outcome was hypocalcemia (endpoint variable). Patients were clinically and biochemically monitored regularly for 48 hours after surgery. RESULTS: Of the patients, 47% developed hypocalcemia (15% symptomatic). An ICMA PTH-5 of ≤14 pg/mL or an ECLIA PTH-5 of ≤16 pg/mL predicted hypocalcemia with a sensitivity of 80%, specificity of 100%, positive predictive value (PPV) of 100%, and diagnostic efficiency (DE) of 91%. Using the same cutoff values, PTH-60 presented a sensitivity of 93%, specificity of 82%, PPV of 81%, and DE of 87%. Adjusting for variation in the assays and combining intra- and postoperative PTH determinations, we developed an algorithm that improved sensitivity, specificity, and DE. CONCLUSION: PTH is useful for predicting hypocalcemia after total thyroidectomy in children. The use of our proposed strategy should be considered to (a) initiate preventive treatment in patients identified at high risk for hypocalcemia, (b) shorten the duration of hospitalization, and (c) reduce the clinical and biochemical controls in those who remained normocalcemic.

Spreading the clinical window for diagnosing fetal-onset hypogonadism in boys.

In early fetal development, the testis secretes - independent of pituitary gonadotropins - androgens and anti-Müllerian hormone (AMH) that are essential for male sex differentiation. In the second half of fetal life, the hypothalamic-pituitary axis gains control of testicular hormone secretion. Follicle-stimulating hormone (FSH) controls Sertoli cell proliferation, responsible for testis volume increase and AMH and inhibin B secretion, whereas luteinizing hormone (LH) regulates Leydig cell androgen and INSL3 secretion, involved in the growth and trophism of male external genitalia and in testis descent. This differential regulation of testicular function between early and late fetal periods underlies the distinct clinical presentations of fetal-onset hypogonadism in the newborn male: primary hypogonadism results in ambiguous or female genitalia when early fetal-onset, whereas it becomes clinically undistinguishable from central hypogonadism when established later in fetal life. The assessment of the hypothalamic-pituitary-gonadal axis in male has classically relied on the measurement of gonadotropin and testosterone levels in serum. These hormone levels normally decline 3-6 months after birth, thus constraining the clinical evaluation window for diagnosing male hypogonadism. The advent of new markers of gonadal function has spread this clinical window beyond the first 6 months of life. In this review, we discuss the advantages and limitations of old and new markers used for the functional assessment of the hypothalamic-pituitary-testicular axis in boys suspected of fetal-onset hypogonadism.