Accuracy of Glucagon Testing Across Transition in Young Adults with Childhood-Onset Growth Hormone Deficiency.

CONTEXT: The 2019 AACE guidelines suggested peak GH-cutoffs to glucagon test (GST) of ≤3 µg/L and ≤1 µg/L in the diagnosis of permanent GH deficiency (GHD) during the transition phase. OBJECTIVE: Aim of the study was to evaluate the accuracy of GST compared to insulin tolerance test (ITT) in the definition of GHD at adult height achievement. PATIENTS AND METHODS: Ninety-seven subjects with childhood-onset GHD (median age, 17.39 years) underwent ITT, GST and IGF-1 testing; 44 subjects were idiopathic (isolated GHD), 35 moderate organic GHD (0-2 hormone deficiencies-HDs) and 18 severe organic GHD (≥3 HDs). RESULTS: Bland and Altman analysis showed a high consistency of GH peak measures after ITT and GST. Receiver operating characteristic analysis-ROC- identified 7.3 µg/L as the optimal GH peak cutoff to GST (95% CI 4.15-8.91; sensitivity 95.7%, specificity 88.2%, positive predictive value-PPV-88.0%, negative predictive value-NPV-95.7%), able to correctly classify 91.8% of the entire cohort while 5.8 µg/L was the best GH peak cutoff able to correctly classify 91.4% of moderate organic GHD patients (95% CI 3.16-7.39; sensitivity 96.0%, specificity 80.0%, PPV 92.3%, NPV 88.9%). Patients with ≥3HDs showed a GH peak <5µg/L at ITT and <5.8µg/L at GST but one. The optimal cutoff for IGF1 was -1.4 SDS (95% CI -1.94-0.77; sensitivity 75%, specificity 94%, PPV 91.7%, NPV 81.0%) that correctly classified 85.1% of the study population. CONCLUSIONS: A GH peak to GST <5.8 µg/L represents an accurate diagnostic cutoff for young adults with childhood-onset GHD and high pre-test probability of permanent GHD.

Blood Lymphocyte Subsets and Proinflammatory Cytokine Profile in ROHHAD(NET) and non-ROHHAD(NET) Obese Individuals.

Context: Rapid-onset obesity with central hypoventilation, hypothalamic dysfunction, and autonomic dysregulation with neural crest tumors (ROHHAD-NET) syndrome pathophysiology remains elusive. Acquired neuroimmunological dysfunction has been proposed as a possible pathogenetic pathway. Objective: The aim of our study was to characterize lymphocyte subpopulations subsets in peripheral blood (PB) and to evaluate a panel of proinflammatory cytokines/chemokines in ROHHAD(NET) patients vs controls. Methods: We included 11 ROHHAD(NET) patients, 7 ROHHAD and 4 ROHHAD-NET, selected by clinical criteria. Controls were 11 simple obese children, matched for age and sex. Flow cytometric analysis and enzyme-linked immunosorbent assay were performed on PB and serum samples of the 2 groups. Results: Analysis revealed that T lymphocytes are significantly increased in ROHHAD(NET) patients (P = .04) with a prevalence of CD4-T cells (P = .03) and a lower number of activated CD8-T cells (P = .02). With regard to regulatory subset, patients displayed increased regulatory B cells (P = .05) and type-1 regulatory T cells (P = .03). With regard to CD8-T cells, a lower number of T effector memory was observed (P = .02). In contrast, among CD4-T cells, we found a higher number of T naive (P = .04) and T effector (P = .0008). Interleukin-8 (IL-8) levels and monocyte chemotactic protein-1 were increased in patients vs controls (P = .008 and P = .01, respectively). Furthermore, IL-8 levels were higher in the subgroup with neural tumor (P = .0058) (ROHHAD-NET) than in patients without neural tumor (ROHHAD). Soluble HLA-G was significantly lower in patients vs controls (P = .03). Conclusion: Our findings contribute to support the hypothesis of immune dysregulation, which may underlie this complex, often fatal disease. Because ROHHAD(NET) syndrome is an ultra-rare disease, multicentric studies are needed to improve the effect of our data in the management of this condition.

Pubertal timing in children with Silver Russell syndrome compared to those born small for gestational age.

Context: Data on pubertal timing in Silver Russell syndrome (SRS) are limited. Design and methods: Retrospective observational study including twenty-three SRS patients [11p15 loss of methylation, (11p15 LOM, n=10) and maternal uniparental disomy of chromosome 7 (mUPD7, n=13)] and 21 small for gestational age (SGA). Clinical (thelarche in females; testis volume ≥ 4 ml in males; pubarche), BMI SD trend from the age of 5 to 9 years to the time of puberty, biochemical parameters of puberty onset [Luteinizing hormone (LH), 17-ß-estradiol, testosterone], and bone age progression were evaluated. Results: Pubertal onset and pubarche occurred significantly earlier in children with SRS than in SGA (p 0.03 and p 0.001, respectively) and clinical signs of puberty onset occurred earlier in mUPD7 than in 11p15LOM group (p 0.003). Five SRS children experienced central precocious puberty and LH, 17-ß-estradiol, testosterone were detected earlier in SRS than in SGA (p 0.01; p 0.0001). Bone age delay in SRS children was followed by rapid advancement; the delta between bone age and chronological age in SRS group became significantly higher than in SGA group at the age of 9-11 years (p 0.007). 11p15LOM patients were underweight at the age of 5 years and showed a progressive normalization of BMI that was significantly higher than in mUPD7 (p 0.04) and SGA groups (p 0.03) at puberty onset. Conclusion: Timing of puberty is affected in SRS and occurred earlier in mUPD7 compared to 11p15LOM. The impact of early puberty on adult height and metabolic status deserves long-term evaluation.

Clinical, Endocrine and Neuroimaging Findings in Girls With Central Precocious Puberty.

CONTEXT: The etiology of central precocious puberty (CPP) includes a spectrum of conditions. Girls younger than age 6 years with CPP should undergo cranial magnetic resonance imaging (MRI), but it remains controversial whether all girls who develop CPP between the ages of 6 and 8 years require neuroimaging examination. OBJECTIVE: To investigate the frequency of brain MRI abnormalities in girls diagnosed with CPP and the relationship between maternal factors, their age at presentation, clinical signs and symptoms, hormonal profiles, and neuroimaging findings. METHODS: Data were collected between January 2005 and September 2019 from 112 girls who showed clinical pubertal progression before 8 years of age who underwent brain MRI. RESULTS: MRI was normal in 47 (42%) idiopathic (I) scans, 54 (48%) patients had hypothalamic-pituitary anomalies (HPA) and/or extra-HP anomalies (EHPA), and 11 (10%) had brain tumors or tumor-like conditions (BT/TL), including 3 with neurological signs. Associated preexisting disorders were documented in 16. Girls with BT/TL had a higher LH peak after GnRH test (P = 0.01) than I, and those older than age 6 years had a higher craniocaudal diameter of the pituitary gland (P = 0.01); their baseline FSH and LH (P = 0.004) and peak FSH (P = 0.01) and LH (P = 0.05) values were higher than I. Logistic regression showed maternal age at menarche (P = 0.02) and peak FSH (P = 0.02) as BT/TL risk factors. CONCLUSIONS: MRI provides valuable information in girls with CPP by demonstrating that fewer than half have a normal brain MRI and that few can have significant intracranial lesions after the age of 6, despite the absence of suggestive neurological signs.

Approach to the Pediatric Patient: Central Diabetes Insipidus.

Central diabetes insipidus (CDI) is a complex disorder in which large volumes of dilute urine are excreted due to arginine-vasopressin deficiency, and it is caused by a variety of disorders affecting the hypothalamic-posterior pituitary network. The differential diagnosis is challenging and requires a detailed medical history, physical examination, biochemical approach, imaging studies, and, in some cases, histological confirmation. Magnetic resonance imaging is the gold standard method for evaluating congenital or acquired cerebral and pituitary stalk lesions. Pituitary stalk size at presentation could be normal, but it may change over time, depending on the underlying condition, while other brain areas or organs may become involved during follow-up. Early diagnosis and treatment are crucial to avoid central nervous system damage and germ cell tumor dissemination and to minimize complications of multiple pituitary hormone defects. We provide a practical update on the diagnosis and management of patients with CDI and highlight several pitfalls that may complicate the differential diagnosis of conditions presenting with polyuria and polydipsia. The need for a careful and close follow-up of patients with apparently idiopathic CDI is particularly emphasized because the underlying condition may be recognized over time. The clinical scenario that we outline at the beginning of this article represents the basis for the discussion about how the etiological diagnosis of CDI can be overlooked and demonstrates how a water intake and urine output improvement can be a sign of progressive damage of both hypothalamus and anterior pituitary gland with associated pituitary hormonal deficiencies.

Advances in differential diagnosis and management of growth hormone deficiency in children.

Growth hormone (GH) deficiency (GHD) in children is defined as impaired production of GH by the pituitary gland that results in growth failure. This disease might be congenital or acquired, and occurs in isolation or in the setting of multiple pituitary hormone deficiency. Isolated GHD has an estimated prevalence of 1 patient per 4000-10,000 live births and can be due to multiple causes, some of which are yet to be determined. Establishing the correct diagnosis remains key in children with short stature, as initiating treatment with recombinant human GH can help them attain their genetically determined adult height. During the past two decades, our understanding of the benefits of continuing GH therapy throughout the transition period from childhood to adulthood has increased. Improvements in transitional care will help alleviate the consequent physical and psychological problems that can arise from adult GHD, although the consequences of a lack of hormone replacement are less severe in adults than in children. In this Review, we discuss the differential diagnosis in children with GHD, including details of clinical presentation, neuroimaging and genetic testing. Furthermore, we highlight advances and issues in the management of GHD, including details of transitional care.

The phenotypic spectrum associated with OTX2 mutations in humans.

Objective: The transcription factor OTX2 is implicated in ocular, craniofacial, and pituitary development. Design: We aimed to establish the contribution of OTX2 mutations in congenital hypopituitarism patients with/without eye abnormalities, study functional consequences, and establish OTX2 expression in the human brain, with a view to investigate the mechanism of action. Methods: We screened patients from the UK (n = 103), international centres (n = 24), and Brazil (n = 282); 145 were within the septo-optic dysplasia spectrum, and 264 had no eye phenotype. Transactivation ability of OTX2 variants was analysed in murine hypothalamic GT1-7 neurons. In situ hybridization was performed on human embryonic brain sections. Genetically engineered mice were generated with a series of C-terminal OTX2 variants. Results: Two chromosomal deletions and six haploinsufficient mutations were identified in individuals with eye abnormalities; an affected relative of one patient harboured the same mutation without an ocular phenotype. OTX2 truncations led to significant transactivation reduction. A missense variant was identified in another patient without eye abnormalities; however, studies revealed it was most likely not causative. In the mouse, truncations proximal to aa219 caused anophthalmia, while distal truncations and the missense variant were tolerated. During human embryogenesis, OTX2 was expressed in the posterior pituitary, retina, ear, thalamus, choroid plexus, and partially in the hypothalamus, but not in the anterior pituitary. Conclusions: OTX2 mutations are rarely associated with hypopituitarism in isolation without eye abnormalities, and may be variably penetrant, even within the same pedigree. Our data suggest that the endocrine phenotypes in patients with OTX2 mutations are of hypothalamic origin.

Endocrine Outcomes In Central Diabetes Insipidus: the Predictive Value of Neuroimaging "Mismatch Pattern".

CONTEXT: The etiology of central diabetes insipidus (CDI) in children is often unknown. Clinical and radiological features at disease onset do not allow discrimination between idiopathic forms and other conditions or to predict anterior pituitary dysfunction. OBJECTIVE: To evaluate the evolution of pituitary stalk (PS) thickening and the pattern of contrast-enhancement in relation with etiological diagnosis and pituitary function. METHODS: We enrolled 39 children with CDI, 29 idiopathic and 10 with Langerhans cell histiocytosis (LCH). Brain magnetic resonance images taken at admission and during follow-up (332 studies) were examined, focusing on PS thickness, contrast-enhancement pattern, and pituitary gland size; T2-DRIVE and postcontrast T1-weighted images were analyzed. RESULTS: Seventeen of 29 patients (58.6%) with idiopathic CDI displayed "mismatch pattern," consisting in a discrepancy between PS thickness in T2-DRIVE and postcontrast T1-weighted images; neuroimaging findings became stable after its appearance, while "mismatch" appeared in LCH patients after chemotherapy. Patients with larger PS displayed mismatch more frequently (P = 0.003); in these patients, reduction of proximal and middle PS size was documented over time (P = 0.045 and P = 0.006). The pituitary gland was smaller in patients with mismatch (P < 0.0001). Patients with mismatch presented more frequently with at least one pituitary hormone defect, more often growth hormone deficiency (P = 0.033). CONCLUSIONS: The PS mismatch pattern characterizes patients with CDI, reduced pituitary gland size, and anterior pituitary dysfunction. The association of mismatch pattern with specific underlying conditions needs further investigation. As patients with mismatch show stabilization of PS size, we assume a prognostic role of this peculiar pattern, which could be used to lead follow-up.

Central diabetes insipidus in children: Diagnosis and management.

Central diabetes insipidus (CDI) is a complex disorder in which large volumes of dilute urine are excreted due to arginine-vasopressin deficiency, and it is caused by a variety of conditions (genetic, congenital, inflammatory, neoplastic, traumatic) that arise mainly from the hypothalamus. The differential diagnosis between diseases presenting with polyuria and polydipsia is challenging and requires a detailed medical history, physical examination, biochemical approach, imaging studies and, in some cases, histological confirmation. Magnetic resonance imaging is the gold standard method for evaluating the sellar-suprasellar region in CDI. Pituitary stalk size at presentation is variable and can change over time, depending on the underlying condition, and other brain areas or other organs - in specific diseases - may become involved during follow up. An early diagnosis and treatment are preferable in order to avoid central nervous system damage and the risk of dissemination of germ cell tumor, or progression of Langerhans Cell Histiocytosis, and in order to start treatment of additional pituitary defects without further delay. This review focuses on current diagnostic work-up and on the role of neuroimaging in the differential diagnosis of CDI in children and adolescents. It provides an update on the best approach for diagnosis - including novel biochemical markers such as copeptin - treatment and follow up of children and adolescents with CDI; it also describes the best approach to challenging situations such as post-surgical patients, adipsic patients, patients undergoing chemotherapy and/or in critical care.

Antibodies Against Hypothalamus and Pituitary Gland in Childhood-Onset Brain Tumors and Pituitary Dysfunction.

Purpose: To detect the presence of antipituitary (APA) and antihypothalamus antibodies (AHA) in subjects treated for brain cancers, and to evaluate their potential association with pituitary dysfunction. Methods: We evaluated 63 patients with craniopharyngioma, glioma, and germinoma treated with surgery and/or radiotherapy and/or chemotherapy at a median age of 13 years. Forty-one had multiple pituitary hormone deficiencies (MPHD), six had a single pituitary defect. GH was the most common defect (65.1%), followed by AVP (61.9%), TSH (57.1%), ACTH (49.2%), and gonadotropin (38.1%). APA and AHA were evaluated by simple indirect immunofluorescence method indirect immunofluorescence in patients and in 50 healthy controls. Results: Circulating APA and/or AHA were found in 31 subjects (49.2%) and in none of the healthy controls. In particular, 25 subjects out of 31 were APA (80.6%), 26 were AHA (83.90%), and 20 were both APA and AHA (64.5%). Nine patients APA and/or AHA have craniopharyngioma (29%), seven (22.6%) have glioma, and 15 (48.4%) have germinoma. Patients with craniopharyngioma were positive for at least one antibody in 39.1% compared to 33.3% of patients with glioma and to 78.9% of those with germinoma with an analogous distribution for APA and AHA between the three tumors. The presence of APA or AHA and of both APA and AHA was significantly increased in patients with germinoma. The presence of APA (P = 0.001) and their titers (P = 0.001) was significantly associated with the type of tumor in the following order: germinomas, craniopharyngiomas, and gliomas; an analogous distribution was observed for the presence of AHA (P = 0.002) and their titers (P = 0.012). In addition, we found a significant association between radiotherapy and APA (P = 0.03). Conclusions: Brain tumors especially germinoma are associated with the development of hypothalamic-pituitary antibodies and pituitary defects. The correct interpretation of APA/AHA antibodies is essential to avoid a misdiagnosis of an autoimmune infundibulo-neurohypophysitis or pituitary hypophysitis in patients with germinoma.

Accuracy and Limitations of the Growth Hormone (GH) Releasing Hormone-Arginine Retesting in Young Adults With Childhood-Onset GH Deficiency.

Background: Re-testing for GH secretion is needed to confirm the diagnosis of GH deficiency (GHD) after adult height achievement in childhood-onset GHD (COGHD). Aim: To define the cut-off of GH peak after retesting with GH-releasing hormone plus arginine (GHRHarg) in the diagnosis of permanent GHD in COGHD of different etiology. Patients and methods: Eighty-eight COGHD (median age 17.2 y), 29 idiopathic GHD (IGHD), 44 cancer survivors (TGHD) and 15 congenital GHD (CGHD) were enrolled in the study; 54 had isolated GHD (iGHD) and 34 had multiple pituitary hormone deficiencies (MPHD). All were tested with insulin tolerance test (ITT) and GHRHarg. IGHD with a GH response to ITT ≥6µg/L were considered true negatives and served as the control group, and patients with a GH response <6µg/L as true positives. Baseline IGF-I was also measured. The diagnostic accuracy of GHRHarg testing and of IGF-I SDS in patients with GHD of different etiologies was evaluated by ROC analysis. Results: Forty-six subjects with a GH peak to ITT ≥6µg/L and 42 with GH peak <6 µg/L showed a GH peak after GHRHarg between 8.8-124µg/L and 0.3-26.3µg/L, respectively; 29 IGHD were true negatives, 42 were true positives and 17 with a high likelihood GHD showed a GH peak to ITT ≥6µg/L. ROC analysis based on the etiology indicated the best diagnostic accuracy for peak GH cutoffs after GHRHarg of 25.3 µg/L in CGHD, 15.7 in TGHD, and 13.8 in MPHD, and for IGF-1 SDS at -2.1 in CGHD, -1.5 in TGHD, and -1.9 in MPHD. Conclusions: Our findings indicate that the best cut-off for GH peak after retesting with GHRHarg changes according to the etiology of GHD during the transition age. Based on these results the diagnostic accuracy of GHRHarg remains questionable.

Role of MRI T2-DRIVE in the assessment of pituitary stalk abnormalities without gadolinium in pituitary diseases.

OBJECTIVE: To investigate the role of T2-DRIVE MRI sequence in the accurate measurement of pituitary stalk (PS) size and the identification of PS abnormalities in patients with hypothalamic-pituitary disorders without the use of gadolinium. DESIGN: This was a retrospective study conducted on 242 patients who underwent MRI due to pituitary dysfunction between 2006 and 2015. Among 135 eligible patients, 102 showed eutopic posterior pituitary (PP) gland and 33 showed 'ectopic' PP (EPP). METHODS: Two readers independently measured the size of PS in patients with eutopic PP at the proximal, midpoint and distal levels on pre- and post-contrast T1-weighted as well as T2-DRIVE images; PS visibility was assessed on pre-contrast T1 and T2-DRIVE sequences in those with EPP. The length, height, width and volume of the anterior pituitary (AP), PP height and length and PP area were analyzed. RESULTS: Significant agreement between the two readers was obtained for T2-DRIVE PS measurements in patients with 'eutopic' PP; a significant difference was demonstrated between the intraclass correlation coefficient calculated on the T2-DRIVE and the T1-pre- and post-contrast sequences. The percentage of PS identified by T2-DRIVE in EPP patients was 72.7% compared to 30.3% of T1 pre-contrast sequences. A significant association was found between the visibility of PS on T2-DRIVE and the height of AP. CONCLUSION: T2-DRIVE sequence is extremely precise and reliable for the evaluation of PS size and the recognition of PS abnormalities; the use of gadolinium-based contrast media does not add significant information and may thus be avoided.

Classical and non-classical causes of GH deficiency in the paediatric age.

Growth hormone deficiency (GHD) may result from a failure of hypothalamic GHRH production or release, from congenital disorders of pituitary development, or from central nervous system insults including tumors, surgery, trauma, radiation or infiltration from inflammatory diseases. Idiopathic, isolated GHD is the most common sporadic form of hypopituitarism. GHD may also occur in combination with other pituitary hormone deficiencies, and is often referred to as hypopituitarism, combined pituitary hormone deficiency (CPHD), multiple pituitary hormone deficiency (MPHD) or panhypopituitarism. Children without any identifiable cause of their GHD are commonly labeled as having idiopathic hypopituitarism. MRI imaging is the technique of choice in the diagnosis of children with hypopituitarism. Marked differences in MRI pituitary gland morphology suggest different etiologies of GHD and different prognoses. Pituitary stalk agenesis and ectopic posterior pituitary (EPP) are specific markers of permanent GHD, and patients with these MRI findings show a different clinical and endocrine outcome compared to those with normal pituitary anatomy or hypoplastic pituitary alone. Furthermore, the classic triad of ectopic posterior pituitary gland, pituitary stalk hypoplasia/agenesis, and anterior pituitary gland hypoplasia is generally associated with permanent GHD. T2 DRIVE images aid in the identification of pituitary stalk without the use of contrast medium administration. Future developments in imaging techniques will undoubtedly reveal additional insights. Mutations in a number of genes encoding transcription factors - such as HESX1, SOX2, SOX3, LHX3, LHX4, PROP1, POU1F1, PITX, GLI3, GLI2, OTX2, ARNT2, IGSF1, FGF8, FGFR1, PROKR2, PROK2, CHD7, WDR11, NFKB2, PAX6, TCF7L1, IFT72, GPR161 and CDON - have been associated with pituitary dysfunction and abnormal pituitary gland development; the correlation of genetic mutations to endocrine and MRI phenotypes has improved our knowledge of pituitary development and management of patients with hypopituitarism, both in terms of possible genetic counseling, and of early diagnosis of evolving anterior pituitary hormone deficiencies.

Sirolimus Therapy in Congenital Hyperinsulinism: A Successful Experience Beyond Infancy.

Congenital hyperinsulinism (CHI) due to diffuse involvement of the pancreas is a challenging and severe illness in children. Its treatment is based on chronic therapy with diazoxide and/or octreotide, followed by partial pancreatectomy, which is often not resolutive. Sirolimus, a mammalian target of rapamycin inhibitor, was reported to be effective in treating CHI in infants. We report here the case of an 8-year-old boy affected by a severe form of CHI due to a biallelic heterozygous ABCC8 mutation who responded to sirolimus with a dramatic improvement in his glucose blood level regulation and quality of life, with no serious adverse events after 6 months of follow-up. To the best of our knowledge, this is the first report of a successful intervention in an older child. It provides a promising basis for further studies comparing sirolimus with other treatments, particularly in older children.