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Context Enthesopathies are the determinant of a poor quality of life in adults with X-linked hypophosphatemia (XLH). Objective To describe the prevalence of patients with enthesopathies and to identify the risk factors of having enthesopathies. Methods Retrospective study in the French Reference Center for Rare Diseases of the Calcium and Phosphate Metabolism between June 2011 and December 2020. Adult XLH patients with full body X-rays performed using the EOS® low-dose radiation system and clinical data collected from medical records. The main outcome measures were demographics, PHEX mutation, conventional treatment, and dental disease with the presence of enthesopathies. Results Of the 114 patients included (68% women, mean age 42.2 ± 14.3 years), PHEX mutation was found in 105 patients (94.6%), 86 (77.5%) had been treated during childhood. Enthesopathies (spine and/or pelvis) were present in 67% of the patients (n = 76). Patients with enthesopathies were significantly older (P = .001) and more frequently reported dental disease collected from medical records (P = .03). There was no correlation between the PHEX mutations and the presence of enthesopathies. Sixty-two patients had a radiographic dental examination in a reference center. Severe dental disease (number of missing teeth, number of teeth endodontically treated, alveolar bone loss, and proportion of patients with 5 abscesses or more) was significantly higher in patients with enthesopathies. Conclusion Adult XLH patients have a high prevalence of enthesopathies in symptomatic adults patients with XLH seen in a reference center. Age and severe dental disease were significantly associated with the presence of enthesopathies.

Acromegaly is a chronic disease due to growth hormone (GH) and insulin-like growth factor 1 (IGF-1) excess. It is associated with various systemic complications including cardiovascular disease. Arterial hypertension occurs in about 20% to 30% of patients. Its pathogenesis is mainly related to the increase in plasma volume secondary to a sodium retaining actions of GH and IGF-1 in the kidney, but abnormalities in vessel architecture and reactivity participate. Left ventricular hypertrophy and diastolic dysfunctions were frequently reported in echo-based studies and are mostly mild and without clinical consequences. Recent cardiac MRI studies described a much lower frequency of myocardial hypertrophy than echo-based assessments. Progression to systolic dysfunction with congestive heart failure is nowadays very rare. Risk of coronary heart disease and of clinically significant arrythmias does not seem to be increased. Acromegaly-related cardiac valve abnormalities may be related to fibrotic changes and seem to persist after effective treatment of acromegaly. Advances in acromegaly treatment over the last decades significantly diminished the cardiovascular burden of the disease, with the cardiovascular disease anymore being the leading cause of death.

Patients with primary bilateral macronodular adrenal hyperplasia (PBMAH) usually present bilateral benign adrenocortical macronodules at imaging and variable levels of cortisol excess. PBMAH is a rare cause of primary overt Cushing's syndrome but may represent up to one-third of bilateral adrenal incidentalomas with evidence of cortisol excess. The increased steroidogenesis in PBMAH is often regulated by various G protein–coupled receptors (GPCRs) aberrantly expressed in PBMAH tissues; some receptor ligands are ectopically produced in PBMAH tissues, creating aberrant autocrine/paracrine regulation of steroidogenesis.The bilateral nature of PBMAH and familial aggregation led to the identification of germline heterozygous inactivating mutations of the ARMC5 gene, in 20% to 25% of the apparent sporadic cases and more frequently in familial cases; ARMC5 mutations/pathogenic variants can be associated with meningiomas. More recently, combined germline mutations/pathogenic variants and somatic events inactivating the KDM1A gene were specifically identified in patients affected by glucose-dependent insulinotropic peptide (GIP)-dependent PBMAH. Functional studies demonstrated that inactivation of KDM1A leads to GIP-receptor (GIPR) overexpression and over- or downregulation of other GPCRs. Genetic analysis is now available for early detection of family members of index cases with PBMAH carrying identified germline pathogenic variants. Detailed biochemical, imaging, and comorbidity assessment of the nature and severity of PBMAH is essential for its management. Treatment is reserved for patients with overt or mild cortisol/aldosterone or other steroid excesses, taking in account comorbidities. It previously relied on bilateral adrenalectomy; however, recent studies tend to favor unilateral adrenalectomy or, less frequently, medical treatment with cortisol synthesis inhibitors or specific blockers of aberrant GPCR.

Background/aim X-linked hypophosphatemia (XLH) is a rare disease characterized by low phosphate levels. Scientific evidence points to a link between hypophosphatemia and obesity in general population. The aim of our longitudinal observational study was to investigate the prevalence of obesity and associated factors in a large cohort of children with XLH. Patients/methods We studied 172 XLH-children 5–20 years of age (113 girls/59 boys). Anthropometric parameters (weight, height, and BMI) were collected at birth and during follow-up at mean ages of 5.3, 8.2, 11.3, and 15.9 years (groups 1, 2, 3, and 4, respectively). In each group, subjects were classified based on International Obesity Taskforce (IOTF) cut off values of BMI for age and sex as overweight or obese (IOTF 25–30 or ≥30 kg/m2, respectively). Results In each age-group, almost 1/3 of XLH-patients were classified as overweight or obese (29.4, 28.7, 27.5, and 36.7% in groups 1, 2, 3, and 4, respectively). Children without a XLH-family history had higher BMI-IOTF at every point of follow-up, compared to those with positive XLH-family history. Similarly, higher BMI-IOTF was significantly associated with treatment duration (23.3 ± 4.4 vs 23.8 ± 3.8 vs 25.2 ± 4.5 kg/m2, for subjects with treatment duration of 10 years, respectively, P for trend = 0.025). Multiple regression analysis confirmed an association of treatment duration and lack of XLH-family history with higher BMI-IOTF. Conclusion One out of three of XLH-children have phenotypically unfavourable metabolic profile expressed as increased prevalence of overweight or obesity in comparison to general population. Both the lack of XLH family history and the duration of treatment increase the risk of higher BMI-IOTF. BMI should be carefully monitored in children, and later in adults, with XLH.

Patients affected by pseudohypoparathyroidism (PHP) or related disorders are characterized by physical findings that may include brachydactyly, a short stature, a stocky build, early-onset obesity, ectopic ossifications, and neurodevelopmental deficits, as well as hormonal resistance most prominently to parathyroid hormone (PTH). In addition to these alterations, patients may develop other hormonal resistances, leading to overt or subclinical hypothyroidism, hypogonadism and growth hormone (GH) deficiency, impaired growth without measurable evidence for hormonal abnormalities, type 2 diabetes, and skeletal issues with potentially severe limitation of mobility. PHP and related disorders are primarily clinical diagnoses. Given the variability of the clinical, radiological, and biochemical presentation, establishment of the molecular diagnosis is of critical importance for patients. It facilitates management, including prevention of complications, screening and treatment of endocrine deficits, supportive measures, and appropriate genetic counselling. Based on the first international consensus statement for these disorders, this article provides an updated and ready-to-use tool to help physicians and patients outlining relevant interventions and their timing. A life-long coordinated and multidisciplinary approach is recommended, starting as far as possible in early infancy and continuing throughout adulthood with an appropriate and timely transition from pediatric to adult care.

This European expert consensus statement provides recommendations for the diagnosis and management of primary hyperparathyroidism (PHPT), chronic hypoparathyroidism in adults (HypoPT), and parathyroid disorders in relation to pregnancy and lactation. Specified areas of interest and unmet needs identified by experts at the second ESE Educational Program of Parathyroid Disorders in 2019 were discussed during two virtual workshops in 2021 and subsequently developed by working groups with interest in the specified areas. PHPT is a common endocrine disease. However, its differential diagnosis of familial hypocalciuric hypercalcemia (FHH), the definition and clinical course of normocalcemic PHPT, and the optimal management of its recurrence after surgery represents areas of uncertainty requiring clarifications. HypoPT is an orphan disease characterized by low calcium concentrations due to insufficient PTH secretion, most often secondary to neck surgery. Prevention and prediction of surgical injury to the parathyroid glands are essential to limit the disease-related burden. Long-term treatment modalities including the place for PTH replacement therapy and the optimal biochemical monitoring and imaging surveillance for complications to treatment in chronic HypoPT need to be refined. The physiological changes in calcium metabolism occurring during pregnancy and lactation modify the clinical presentation and management of parathyroid disorders in these periods of life. Modern interdisciplinary approaches to PHPT and HypoPT in pregnant and lactating women and their newborn children are proposed. The recommendations on clinical management presented here will serve as background for further educational material aimed at a broader clinical audience and were developed with the focus on endocrinologists in training.

This review focuses on the commonly prescribed medicaments that can be responsible for hypercalcemia, considering the prevalence, the predominant pathophysiological mechanisms, and the optimal medical management of each drug-induced hypercalcemia. Vitamin D supplements and 1α-hydroxylated vitamin D analogues increase intestinal calcium absorption, renal calcium reabsorption as well as bone resorption. In patients with hypoparathyroidism receiving recombinant human PTH, transient hypercalcemia can occur because of overtreatment, usually during acute illness. Thiazide-induced hypercalcemia is mainly explained by enhanced renal proximal calcium reabsorption, changing preexistent asymptomatic normocalcemic or intermittently hypercalcemic hyperparathyroidism into the classic hypercalcemic hyperparathyroidism. Lithium causes hypercalcemia mainly by drug-induced hyperparathyroidism.

Context Cardiovascular disease is the leading cause of death in patients with Cushing syndrome. Cortisol excess and adverse metabolic profile could increase cardiac fat, which can subsequently impair cardiac structure and function. Objective We aimed to evaluate cardiac fat mass and distribution in patients with Cushing syndrome. Methods In this prospective, cross-sectional study, 23 patients with Cushing syndrome and 27 control individuals of comparable age, sex, and body mass index were investigated by cardiac magnetic resonance imaging and proton spectroscopy. Patients were explored before and after biochemical disease remission. Myocardial fat measured by the Dixon method was the main outcome measure. The intramyocardial triglyceride/water ratio measured by spectroscopy and epicardial and pericardial fat volumes were secondary outcome measures. Results No difference was found between patients and controls in intramyocardial lipid content. Epicardial fat mass was increased in patients compared to controls (30.8 g/m2 [20.4-34.8] vs 17.2 g/m2 [13.1-23.5], P Conclusion Intramyocardial fat stores are not increased in patients with Cushing syndrome, despite highly prevalent metabolic syndrome, suggesting increased cortisol-mediated lipid consumption. Cushing syndrome is associated with marked accumulation of epicardial and pericardial fat. Epicardial adiposity may exert paracrine proinflammatory effects promoting cardiomyopathy.

Purpose To examine the MRI diagnostic performance in the assessment of therapeutic response to burosumab in children with X-linked hypophosphatemia (XLH). Design Prospective longitudinal open cohort. Patients Seventeen children with XLH, average age of 10.2 ± 2.7 years, had a knee MRI at baseline and after 1 year of burosumab. Intervention Children received burosumab at an average dose of 1.4 ± 0.5 mg/kg during 1 year for the treatment of severe rickets (the target serum phosphate ≥ 1.2 mmol/L (≥3.7 mg/dL). The primary endpoint was the change from baseline to 12 months in rachitic lesions on knee MRI. Secondary endpoints were changes in biochemical parameters of phosphate and alkaline phosphatase (ALP). Results One year of treatment with burosumab significantly reduced radiological disease activity on knee MRI (by 44 ± 29% in the transverse extent of widening) which was accompanied by a significant reduction in biochemical activity, namely in serum ALP activity, by 28 ± 17%. Additionally, MRI parameters after 1 year of treatment with burosumab (the maximum width of medial physis at 12 months and the change from baseline in the maximum width of lateral physis) were associated with ALP activity at 12 months. Conclusion We suggest that MRI is a valuable and quantitative tool to evaluate the therapeutic response to burosumab. MRI could be an excellent alternative to standard bone radiographs for evaluation of the rachitic lesions in a clinical setting avoiding repeated exposition to ionizing radiation.

Objectif Hormis les mutations de GNAS, la pathogenie moleculaire des adenomes hypophysaires somatotropes est mal connue. Recemment, nous avons decrit, chez des patients acromegales presentant une reponse paradoxale de la GH (Growth Hormone) a la charge orale en glucose, un sous-groupe d’adenomes, sans mutation de GNAS, ayant une expression hypophysaire ectopique du recepteur du GIP (Glucose-dependent Insulinotropic Peptide). L’objectif de ce travail a ete d’analyser le couplage fonctionnel du GIPR hypophysaire a la secretion de la GH. Methodes Nous avons etudie, par transfection transitoire, l’impact de la surexpression du GIPR humain dans les lignees cellulaires somatotropes GH3 et GC. L’immunofluorescence nous a permis de verifier la surexpression du GIPR; l’activation de la voie de l’AMPc ainsi que la secretion de GH ont ete mesurees apres stimulation des cellules par le GIP. Resultats Nous avons montre que l’expression endogene du GIPR, dans ces deux modeles cellulaires, ne permet pas l’activation de la voie de l’AMPc aux concentrations physiologiques de GIP. En revanche, la surexpression du GIPR augmente la sensibilite des cellules au ligand. En effet, le GIP induit la production d’AMPc a des concentrations inferieures de deux logs decimaux dans les cellules transfectees par rapport aux cellules controles. De plus, a stimulation equivalente, elles secretent davantage de GH (8,143 vs 4,555 ng/L/10 000 cellules, p = 0,0079). Discussion Le GIPR, surexprime dans des cellules somatotropes, est fonctionnellement couple a la voie de l’AMPc et sa stimulation augmente la secretion de GH.

Summary Background GIP-dependent primary bilateral macronodular adrenal hyperplasia with Cushing's syndrome is caused by aberrant expression of the GIP receptor in adrenal lesions. The bilateral nature of this disease suggests germline genetic predisposition. We aimed to identify the genetic driver event responsible for GIP-dependent primary bilateral macronodular adrenal hyperplasia with Cushing's syndrome. Methods We conducted a multicentre, retrospective, cohort study at endocrine hospitals and university hospitals in France, Canada, Italy, Greece, Belgium, and the Netherlands. We collected blood and adrenal samples from patients who had undergone unilateral or bilateral adrenalectomy for GIP-dependent primary bilateral macronodular adrenal hyperplasia with Cushing's syndrome. Adrenal samples from patients with primary bilateral macronodular adrenal hyperplasia who had undergone an adrenalectomy for overt or mild Cushing's syndrome without evidence of food-dependent cortisol production and those with GIP-dependent unilateral adrenocortical adenomas were used as control groups. We performed whole genome, whole exome, and targeted next generation sequencing, and copy number analyses of blood and adrenal DNA from patients with familial or sporadic disease. We performed RNA sequencing on adrenal samples and functional analyses of the identified genetic defect in the human adrenocortical cell line H295R. Findings 17 patients with GIP-dependent primary bilateral macronodular adrenal hyperplasia with Cushing's syndrome were studied. The median age of patients was 43·3 (95% CI 38·8–47·8) years and most patients (15 [88%]) were women. We identified germline heterozygous pathogenic or most likely pathogenic variants in the KDM1A gene in all 17 patients. We also identified a recurrent deletion in the short p arm of chromosome 1 harboring the KDM1A locus in adrenal lesions of these patients. None of the 29 patients in the control groups had KDM1A germline or somatic alterations. Concomitant genetic inactivation of both KDM1A alleles resulted in loss of KDM1A expression in adrenal lesions. Global gene expression analysis showed GIP receptor upregulation with a log2 fold change of 7·99 (95% CI 7·34–8·66; p=4·4 × 10−125), and differential regulation of several other G protein-coupled receptors in GIP-dependent primary bilateral macronodular hyperplasia samples compared with control samples. In vitro pharmacological inhibition and inactivation of KDM1A by CRISPR-Cas9 genome editing resulted in an increase of GIP receptor transcripts and protein in human adrenocortical H295R cells. Interpretation We propose that GIP-dependent primary bilateral macronodular adrenal hyperplasia with Cushing's syndrome results from a two-hit inactivation of KDM1A, consistent with the tumour suppressor gene model of tumorigenesis. Genetic testing and counselling should be offered to these patients and their relatives. Funding Agence Nationale de la Recherche, Fondation du Grand defi Pierre Lavoie, and the French National Cancer Institute.

To gain more insight on the pathogenesis of somatotroph pituitary adenomas, recent studies have focused on a subgroup of patients with acromegaly displaying a paradoxical growth hormone (GH) response during oral glucose tolerance test (OGTT). The paradoxical rise of GH after oral glucose intake occurs in about one-third of acromegaly patients and has been pathogenetically linked, by analogy to glucose-dependent insulinotropic polypeptide (GIP)-dependent Cushing's syndrome, to the ectopic expression of GIP receptor (GIPR) in somatotroph adenoma cells. GIPR-expressing adenomas are negative for activating GNAS gene mutations and display distinct cytogenetic and DNA methylation profiles, highlighting their unique molecular pathogenesis. Acromegaly patients with a paradoxical GH response pattern seem to display higher insulin-like growth factor-1 (IGF-1) concentrations and harbour smaller adenomas that are more often of the densely granulated phenotype. They seem also to show a better response to somatostatin receptor ligands. In addition, persistent paradoxical GH response after surgery may be a biological marker of the residual disease postoperatively. Targeted therapy to antagonize GIP receptor on GIPR-expressing somatotroph adenomas could be a new treatment approach for acromegaly patients with a paradoxical pattern of GH response to OGTT.

International audience; X-linked hypophosphatemia (XLH) is caused by mutations in the PHEX gene which result in Fibroblast Growth Factor-23 (FG-F23) excess and phosphate wasting. Clinically, XLH children present with rickets, bone deformities and short stature. In adulthood, patients may still be symptomatic with bone and joint pain, osteomalacia-related fractures or pseudofractures, precocious osteoarthrosis, enthesopathy, muscle weakness and severe dental anomalies. Besides these musculoskeletal and dental manifestations, adult XLH patients are also prone to secondary and tertiary hyperparathyroidism, cardiovascular and metabolic disorders. Pathophysiology of hyperparathyroidism is only partially understood but FGF23 excess and deficient production of calcitriol likely contributes to its development. Similarly, the pathophysiological mechanisms of potential cardiovascular and metabolic involvements are not clear, but FGF-23 excess may play an essential role. Treatment should be considered in symptomatic patients, patients undergoing orthopedic or dental surgery and women during pregnancy and lactation. Treatment with oral phosphate salts and active vitamin D analogs has incomplete efficacy and potential risks. Burosumab, a recombinant human monoclonal antibody against FGF-23, has proven its efficacy in phase 2 and phase 3 clinical trials in adult patients with XLH, but currently its position as first line or second line treatment differ among the countries.

Background Non-classic 21-hydroxylase deficiency is usually diagnosed in post-pubertal women because of androgen excess. Indication of systematic steroid replacement therapy is controversial because the risk of acute adrenal insufficiency is unknown. In order to specify this risk we evaluated the cortisol and aldosterone secretions in response to appropriate pharmacologic challenges. Methods In this prospective case–control non-inferiority study we investigated 20 women with non-classic 21-hydroxylase deficiency carrying biallelic CYP21A2 mutations and with serum 17-hydroxyprogesterone (17OHP) >10 ng/mL after stimulation with Synacthen® (tetracosactrin) and 20 age- and body mass index-matched healthy women with 17OHP after Synacthen® Findings The peak serum cortisol concentration after insulin hypoglycemia was lower in patients than in controls (mean difference –47 ng/mL, 90% CI, –66, P = 0.0026). A peak serum cortisol above a cutoff value of 170 ng/mL was obtained in all controls but only in 55% of patients (P = 0.0039). Twenty-four hours after sodium depletion, blood pressure, plasma sodium, potassium, and serum aldosterone concentrations were comparable between the two groups, but patients had higher stimulated renin concentrations than controls (P = 0.0044). Interpretation Patients with non-classic 21-hydroxylase deficiency frequently display partial cortisol insufficiency and compensated defect in aldosterone secretion. Their clinical management should systematically include assessment of adrenal functions.

Acromegaly is a chronic disease due to growth hormone (GH) and insulin-like growth hormone I (IGF-I) excess. It is associated with various systemic complications including secondary hypertension that occurs in about 20–30% of patients. The pathogenesis of hypertension is mainly related to the increase in plasma volume secondary to sodium retaining actions of GH and IGF-I in the kidney. Both the hormones exert a direct antinatriuretic action in the distal nephron by stimulating the epithelial sodium channel (ENaC)-dependent sodium reabsorption. Indirect action of GH/IGF-I, via stimulation of the renin–angiotensin–aldosterone system, implicated in hormonal fine-tuning of sodium homeostasis in the distal tubule, is still controversial. In addition, abnormalities in vessel architecture and reactivity as well as other systemic complications of acromegaly such as insulin resistance, diabetes mellitus, and sleep apnea syndrome participate in the pathogenesis of high blood pressure. Advances in acromegaly treatment over the last decades significantly changed the burden of the disease, with the cardiovascular disease not more being the leading cause of death. The biochemical control of acromegaly leads in some patients to improvement or remission of hypertension. In the remaining patients, antihypertensive drugs should be used as in essential hypertension.

BackgroundsThe incidence of germline mutations in the newly discovered cryptic exon (E1’) of VHL gene in patients with von Hippel-Lindau (VHL) disease and in patients with paraganglioma or pheochromocytoma (PPGL) is not currently known.MethodsWe studied a large international multicentre cohort of 1167 patients with a previous negative genetic testing. Germline DNA from 75 patients with a single tumour of the VHL spectrum (‘Single VHL tumour’ cohort), 70 patients with multiple tumours of the VHL spectrum (‘Multiple VHL tumours’ cohort), 76 patients with a VHL disease as described in the literature (‘VHL-like’ cohort) and 946 patients with a PPGL were screened for E1’ genetic variants.ResultsSix different genetic variants in E1' were detected in 12 patients. Two were classified as pathogenic, 3 as variants of unknown significance and 1 as benign. The rs139622356 was found in seven unrelated patients but described in only 16 patients out of the 31 390 of the Genome Aggregation Database (pConclusionsVHL E1’ cryptic exon mutations contribute to 1.32% (1/76) of ‘VHL-like’ cohort and to 0.11% (1/946) of PPGL cohort and should be screened in patients with clinical suspicion of VHL, and added to panels for Next Generation Sequencing (NGS) diagnostic testing of hereditary PPGL. Our data highlight the importance of studying variants identified in deep intronic sequences, which would have been missed by examining only coding sequences of genes/exomes. These variants will likely be more frequently detected and studied with the upcoming implementation of whole-genome sequencing into clinical practice.

In X-linked hypophosphatemia (XLH), inherited loss-of-function mutations in the PHEX gene cause excess circulating levels of fibroblast growth factor 23 (FGF23), leading to lifelong renal phosphate wasting and hypophosphatemia. Adults with XLH present with chronic musculoskeletal pain and stiffness, short stature, lower limb deformities, fractures, and pseudofractures due to osteomalacia, accelerated osteoarthritis, dental abscesses, and enthesopathy. Burosumab, a fully human monoclonal antibody, binds and inhibits FGF23 to correct hypophosphatemia. This report summarizes results from a double-blind, placebo-controlled, phase 3 trial of burosumab in symptomatic adults with XLH. Participants with hypophosphatemia and pain were assigned 1:1 to burosumab 1 mg/kg (n = 68) or placebo (n = 66) subcutaneously every 4 weeks (Q4W) and were comparable at baseline. Across midpoints of dosing intervals, 94.1% of burosumab-treated participants attained mean serum phosphate concentration above the lower limit of normal compared with 7.6% of those receiving placebo (p < 0.001). Burosumab significantly reduced the Western Ontario and the McMaster Universities Osteoarthritis Index (WOMAC) stiffness subscale compared with placebo (least squares [LS] mean ± standard error [SE] difference, -8.1 ± 3.24; p = 0.012). Reductions in WOMAC physical function subscale (-4.9 ± 2.48; p = 0.048) and Brief Pain Inventory worst pain (-0.5 ± 0.28; p = 0.092) did not achieve statistical significance after Hochberg multiplicity adjustment. At week 24, 43.1% (burosumab) and 7.7% (placebo) of baseline active fractures were fully healed; the odds of healed fracture in the burosumab group was 16.8-fold greater than that in the placebo group (p < 0.001). Biochemical markers of bone formation and resorption increased significantly from baseline with burosumab treatment compared with placebo. The safety profile of burosumab was similar to placebo. There were no treatment-related serious adverse events or meaningful changes from baseline in serum or urine calcium, intact parathyroid hormone, or nephrocalcinosis. These data support the conclusion that burosumab is a novel therapeutic addressing an important medical need in adults with XLH.© 2018 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals, Inc.

Objectif Les mecanismes moleculaires de l’envahissement des sinus caverneux par les adenomes hypophysaires sont mal connus. Recemment, en comparant les profils d’expression genique des portions intrasellaires et de celles envahissant le sinus caverneux d’adenomes hypophysaires, nous avons decrit la signature moleculaire du comportement invasif. L’objectif de notre projet est d’examiner in vivo, en tenant compte de l’importance du microenvironnement tumoral, l’implication de certains genes dans l’acquisition du phenotype invasif. Dans ce but, nous avons concu un modele orthotopique de tumeurs hypophysaires somatotropes chez le rat. Methodes Nous avons elabore un protocole original de chirurgie stereotaxique d’injection dans les lobes hypophysaires lateraux de rates. Des rates de souches Wistar Wi et Wistar Han ont recu 20 000 cellules somatotropes GC (groupes traites; n = 3/souche) ou du vehicule (groupes controles; Wistar Wi, n = 3, Wistar Han, n = 2). Apres la stereotaxie, nous avons suivi les rates pendant 20 semaines (poids, taille, IGF1, IRM). Resultats Aucune tumeur n’est apparue dans les groupes controles, alors que chez 50 % des rates injectees avec les cellules GC, de volumineuses tumeurs hypophysaires invasives se sont developpees rapidement (6–10 semaines) et se sont manifestees cliniquement par une insuffisance corticotrope aigue. Malgre une croissance tumorale rapide, aucun acromegalogigantisme n’a ete observe. Discussion Nous demontrons la faisabilite d’un modele d’adenomes hypophysaires invasifs chez le rat par injections stereotaxiques de cellules somatotropes dans les lobes hypophysaires. La cinetique de la croissance tumorale sera prochainement evaluee sur un plus grand nombre d’animaux par des IRM 7 Tesla (MIRCen, CEA) toutes les 3 semaines.

Introduction/objectif L’hyperparathyroidie est une manifestation tres frequente dans le cadre de l’hypophosphatemie liee a l’X (XLH). Bien que le mecanisme patho-physiologique ne soit pas bien connu, on suppose que la supplementation en phosphate peut stimuler la secretion de l’hormone parathyroidienne (PTH). Un niveau eleve de FGF23, caracteristique d’XLH, favorise la synthese de PTH et contribue ainsi au developpement de l’hyperparathyroidie. Nous avons etudie l’effet du traitement anti-FGF23 par burosumab sur l’hyperparathyroidie chez les enfants atteints d’XLH. Materiels/methodes 62 enfants atteints d’XLH (40 filles/22 garcons ; 9,1 ± 3,6 ans) traites par burosumab. Les parametres comme le phosphore/calcium sanguins, TmP/eGFR, ALP, 1,25(OH)2D, PTH ont ete controles au debut (M0) et apres 3-6-12-18 mois de traitement (M3-M6-M12-M18). Le diagnostic d’hyperparathyroidie a ete retenu si les taux de PTH etaient superieurs a la limite superieure de la norme (n : 18,5-88 ng/l). Resultats Avant traitement par burosumab, 11 patients (21,5 %) avaient une hyperparathyroidie secondaire. Ils presentaient des taux eleves de PTH (88 ± 39 ng/l) et des taux normaux de calcium sanguin (2,44 ± 0,17 mmol/l). Les enfants atteints d’hyperparathyroidie etaient plus âges que ceux sans hyperparathyroidie (12,0 ± 3,6 vs 8,5 ± 3,3 ans, p = 0,002) et ont recu des supplements de phosphore pendant plus longtemps (10,7 ± 3,9 vs 6,2 ± 3,3 ans, p = 0,000). Sous burosumab les taux de PTH ont diminue chez les enfants atteints d’hyperparathyroidie (M0-M3-M6-M12-M18 : PTH 88 ± 39-76 ± 24-71 ± 16-84 ± 27-75 ± 12 ng/l, p = 0,7). Aucun patient n’a developpe d’hypercalcemie. Conclusion Nos resultats suggerent que le traitement anti-FGF23 semble limiter, voire controler, l’hyperparathyroidie chez les enfants atteints de XLH. Neanmoins, un suivi plus long est indispensable afin de mieux comprendre ce phenomene.

Contexte L’envahissement des sinus caverneux par les tumeurs hypophysaires compromet la guerison par le traitement chirurgical. Les approches pharmacologiques sont peu efficaces sur les portions intracaverneuses des tumeurs, des therapies ciblees seraient utiles. Cependant, les mecanismes de l’envahissement des sinus caverneux ne sont pas connus. Notre objectif est d’identifier les acteurs moleculaires responsables de l’invasion du sinus caverneux par les tumeurs hypophysaires gonadotropes. Methodes Nous avons compare par RNA-seq les profils d’expressions geniques des portions non-invasives (intra-sellaires) et des portions envahissant le sinus caverneux de 19 tumeurs hypophysaires, dont 14 tumeurs gonadotropes. Nous avons analyse l’impact d’un gene candidat sur l’invasion et la migration cellulaire par Transwell Assay en inhibant son activite dans des lignees hypophysaires GH3 et LβT2. Resultats Nous avons identifie dans les portions invasives des tumeurs gonadotropes 159 genes surexprimes et 11 genes sous-exprimes. Nous avons notamment observe une surexpression d’un gene candidat qui represente une cible therapeutique interessante, puisque ses inhibiteurs pharmacologiques sont deja utilises chez l’Homme. L’inhibition de son activite dans des lignees GH3 et LβT2 a pour consequence une diminution de la migration (p = 0,0204 et p = 0,0281, respectivement) et de l’invasion cellulaire (p = 0,0038 et p = 0,0992, respectivement). Conclusion Grace a une collection tissulaire unique, nous avons decrit une signature moleculaire associee a l’envahissement du sinus caverneux et identifie un gene candidat qui ouvre de nouvelles perspectives therapeutiques. Les etudes in vitro seront completees par l’injection stereotaxique de cellules transgeniques dans des hypophyses de rats afin d’etudier l’impact fonctionnel du gene candidat in vivo.

International audience; Since the initial description of glucose-dependent insulinotropic polypeptide (GIP)–dependent Cushing's syndrome, the molecular mechanisms leading to aberrant expression of G protein–coupled receptors in the adrenocortical adenomas and bilateral adrenal hyperplasia have excited scientific curiosity. This review addresses the recent advances in our understanding of the molecular pathogenesis of GIP-dependent Cushing's syndrome, focusing in particular on two novel findings reported by our group two years ago. First, we discuss the observations of monoallelic GIP receptor (GIPR) expression and transcriptional heterogeneity in GIPR-expressing adrenal lesions, corroborated recently by similar findings in GIPR-expressing somatotroph pituitary adenomas from patients with acromegaly. Second, we review the findings of 19q13.32 microduplications and chromosome rearrangements as molecular hits leading to adrenal GIPR expression in some adrenocortical adenomas. We further discuss some unanswered questions and future research directions, such as the molecular mechanisms leading to GIPR expression in bilateral adrenal hyperplasia, the putative mechanisms of several aberrant hormone receptor coexpression, and the respective role of aberrant receptors as factors modifying steroidogenesis and as molecular drivers responsible for tumor development. Finally, we review the potential therapeutic implications of aberrant receptors in the treatment of bilateral adrenal lesions.

The Growth Hormone Research Society (GRS) convened a Workshop in March 2019 to evaluate the diagnosis and therapy of short stature in children. Forty-six international experts participated at the invitation of GRS including clinicians, basic scientists, and representatives from regulatory agencies and the pharmaceutical industry. Following plenary presentations addressing the current diagnosis and therapy of short stature in children, breakout groups discussed questions produced in advance by the planning committee and reconvened to share the group reports. A writing team assembled one document that was subsequently discussed and revised by participants. Participants from regulatory agencies and pharmaceutical companies were not part of the writing process. Short stature is the most common reason for referral to the pediatric endocrinologist. History, physical examination, and auxology remain the most important methods for understanding the reasons for the short stature. While some long-standing topics of controversy continue to generate debate, including in whom, and how, to perform and interpret growth hormone stimulation tests, new research areas are changing the clinical landscape, such as the genetics of short stature, selection of patients for genetic testing, and interpretation of genetic tests in the clinical setting. What dose of growth hormone to start, how to adjust the dose, and how to identify and manage a suboptimal response are still topics to debate. Additional areas that are expected to transform the growth field include the development of long-acting growth hormone preparations and other new therapeutics and diagnostics that may increase adult height or aid in the diagnosis of growth hormone deficiency. info:eu-repo/semantics/publishedVersion

In adults with X‐linked hypophosphatemia (XLH), excess FGF23 impairs renal phosphate reabsorption and suppresses production of 1,25‐dihydroxyvitamin D, resulting in chronic hypophosphatemia and persistent osteomalacia. Osteomalacia is associated with poor bone quality causing atraumatic fractures, pseudofractures, delayed fracture healing, and bone pain. Burosumab is a fully human monoclonal antibody against FGF23. UX023‐CL304 is an ongoing, open‐label, single‐arm, phase 3 study investigating the efficacy of subcutaneous burosumab, 1.0 mg/kg administered every 4 weeks, in improving osteomalacia in adults with XLH who have not been treated for at least 2 years before enrollment. The primary endpoint was improvement in osteoid volume/bone volume assessed by transiliac bone biopsies obtained at baseline and week 48. Additional assessments included serum phosphorus, markers of bone turnover, fracture/pseudofracture healing, and safety. Fourteen subjects enrolled, 13 completed 48 weeks, and 11 completed paired biopsies. All osteomalacia‐related histomorphometric measures improved significantly at week 48 (mean percent change: osteoid volume/bone volume, –54%, osteoid thickness, –32%, osteoid surface/bone surface, –26%, [median] mineralization lag time, –83%). Mean serum phosphorus concentration averaged across the mid‐point of the dose cycle between weeks 0 and 24 was 3.3 mg/dL, a 50% increase from 2.2 mg/dL at baseline. Markers of bone formation and resorption increased at week 48 (least squares [LS] mean increase: P1NP, +77%; CTx, +36%; both p

Germline mutations in the aryl hydrocarbon receptor-interacting protein (AIP) gene predispose humans to pituitary adenomas, particularly of the somatotroph lineage. Mice with global heterozygous inactivation of Aip (Aip+/−) also develop pituitary adenomas but differ from AIP-mutated patients by the high penetrance of pituitary disease. The endocrine phenotype of these mice is unknown. The aim of this study was to determine the endocrine phenotype of Aip+/− mice by assessing the somatic growth, ultradian pattern of GH secretion and IGF1 concentrations of longitudinally followed male mice at 3 and 12 months of age. As the early stages of pituitary tumorigenesis are controversial, we also studied the pituitary histology and somatotroph cell proliferation in these mice. Aip+/− mice did not develop gigantism but exhibited a leaner phenotype than wild-type mice. Analysis of GH pulsatility by deconvolution in 12-month-old Aip+/− mice showed a mild increase in total GH secretion, a conserved GH pulsatility pattern, but a normal IGF1 concentration. No pituitary adenomas were detected up to 12 months of age. An increased ex vivo response to GHRH of pituitary explants from 3-month-old Aip+/− mice, together with areas of enlarged acini identified on reticulin staining in the pituitary of some Aip+/− mice, was suggestive of somatotroph hyperplasia. Global heterozygous Aip deficiency in mice is accompanied by subtle increase in GH secretion, which does not result in gigantism. The absence of pituitary adenomas in 12-month-old Aip+/− mice in our experimental conditions demonstrates the important phenotypic variability of this congenic mouse model.

PURPOSE Cushing's disease (CD) is associated with alterations in cardiac geometry and function, shown to be reversible after treatment. Our aim was to study cortisol-related changes in myocardial content in CD at baseline and after treatment using MR myocardial T1 times. MATERIALS AND METHODS This is a longitudinal study performed in 10 patients with active CD matched with 10 hypertensive and 10 healthy controls. All subjects had MR after CD diagnosis and 6 months after cortisol normalization. The 1.5 Tesla MR protocol included left ventricular geometry and function assessment and MOLLI sequences before and after contrast injection as well as late gadolinium enhancement. RESULTS At baseline, native myocardial T1 was significantly higher in CD patients compared with controls and the hypertensive group (1056 ± 139 ms versus 929 ± 80 ms, P = 0.023; 1056 ± 139 ms versus 952 ± 51, P = 0.049). After treatment, native and postcontrast myocardial T1 decreased in CD patients versus controls (1056 ± 139 ms versus 832 ± 78, P = 0.006 and 483 ± 69 ms versus 395 ± 39 ms, P = 0.010) reaching values even lower than found in controls (P = 0.038 and P = 0.001, respectively). CONCLUSION Native myocardial T1 is increased in Cushing's disease independently from hypertension and notably decreases after effective treatment, highlighting its potential to detect subclinical diffuse myocardial involvement in this condition. LEVEL OF EVIDENCE 2 J. Magn. Reson. Imaging 2017;45:147-156.

Introduction Calcific aortic valve stenosis (CAVS) is a serious clinical problem. The strongest predictor of CAVS progression is the amount of calcium in the aortic valve. The pathogenesis of CAVS is largely consistent with the pathogenesis of atherosclerosis; however, about 50% of patients with CAVS do not exhibit significant atherosclerosis. Cardiovascular calcification is currently considered an actively regulated process, in which the important role is attributed to the RANKL/RANK/OPG (receptor activator of nuclear factor κB ligand/RANK/osteoprotegerin) axis. We measured OPG levels in the tissue of calcified, stenotic aortic valves in relation to the presence or absence of coronary artery disease (CAD). Materials and methods Aortic valve samples were collected from 105 patients with calcified, mainly severe aortic stenosis, who were divided into two groups according to the presence of CAD. In Group A ( n = 44), there were normal coronary artery findings, while in Group B ( n = 61), there was angiographically demonstrated > 50% stenosis of at least one coronary artery. The control Group C ( n = 21) consisted of patients without aortic stenosis and with normal angiographic findings on coronary arteries. Results The highest tissue concentrations of OPG [median (pmol/L), 25th–75th percentile] were found in Group A [6.95, 3.96–18.37], which was significantly different compared to the other two groups ( P = .026 and .001, respectively). The levels of OPG in Group B [4.15, 2.47–9.16] and in Group C [2.25, 1.01–5.08] did not differ significantly ( P = .078); however, the lowest concentrations of OPG were found in Group C. Neither age nor gender in our study had effect on tissue levels of OPG ( P = .994 for gender; P = .848 for age). Conclusion Calcified and narrowed aortic valves, compared to the normal valves, were accompanied by a change in tissue concentrations of OPG, which is, in addition, dependent on the presence or absence of CAD. The highest tissue concentrations of OPG in our work were found in patients with significant aortic stenosis without concomitant CAD.

The exact physiological basis of acute growth hormone (GH) suppression by oral glucose is not fully understood. Glucose-mediated increase in hypothalamic somatostatin seems to be the most plausible explanation. Attempts to better understand its underlying mechanisms are compromised by species disparities in the response of GH to glucose load. While in humans, glucose inhibits GH release, the acute elevation of circulating glucose levels in rats has either no effect on GH secretion or may be stimulatory. Likewise, chronic hyperglycemia alters GH release in both humans and rats nonetheless in opposite directions. Several factors influence nadir GH concentrations including, age, gender, body mass index, pubertal age, and the type of assay used. Besides the classical suppressive effects of glucose on GH release, a paradoxical GH increase to oral glucose may be observed in around one third of patients with acromegaly as well as in various other disorders. Though its pathophysiology is poorly characterized, an altered interplay between somatostatin and GH-releasing hormone has been suggested and a link with pituitary ectopic expression of glucose-dependent insulinotropic polypeptide receptor has been recently demonstrated. A better understanding of the dynamics mediating GH response to glucose may allow a more optimal use of the OGTT as a diagnostic tool in various conditions, especially acromegaly.

This Consensus Statement covers recommendations for the diagnosis and management of patients with pseudohypoparathyroidism (PHP) and related disorders, which comprise metabolic disorders characterized by physical findings that variably include short bones, short stature, a stocky build, early-onset obesity and ectopic ossifications, as well as endocrine defects that often include resistance to parathyroid hormone (PTH) and TSH. The presentation and severity of PHP and its related disorders vary between affected individuals with considerable clinical and molecular overlap between the different types. A specific diagnosis is often delayed owing to lack of recognition of the syndrome and associated features. The participants in this Consensus Statement agreed that the diagnosis of PHP should be based on major criteria, including resistance to PTH, ectopic ossifications, brachydactyly and early-onset obesity. The clinical and laboratory diagnosis should be confirmed by a molecular genetic analysis. Patients should be screened at diagnosis and during follow-up for specific features, such as PTH resistance, TSH resistance, growth hormone deficiency, hypogonadism, skeletal deformities, oral health, weight gain, glucose intolerance or type 2 diabetes mellitus, and hypertension, as well as subcutaneous and/or deeper ectopic ossifications and neurocognitive impairment. Overall, a coordinated and multidisciplinary approach from infancy through adulthood, including a transition programme, should help us to improve the care of patients affected by these disorders, This Consensus Statement and the series of consensus meetings were supported by funds from the European Cooperation in Science and Technology (COST) action BM1208 on imprinting disorders (www.imprinting- disorders.eu), the European Society for Paediatric Endocrinology (ESPE) and the European Society for Endocrinology (ESE). Travel costs and housing of the representatives of the Asian Pacific Paediatric Endocrine Society (APPES) and of the Pediatric Endocrine Society (PES) were supported by their societies. The authors received no funding from pharmaceutical companies

Context Besides GNAS gene mutations, the molecular pathogenesis of somatotroph adenomas responsible for gigantism and acromegaly remains elusive. Objective To investigate alternative driver events in somatotroph tumorigenesis, focusing on a subgroup of acromegalic patients with a paradoxical increase in growth hormone (GH) secretion after oral glucose, resulting from ectopic glucose-dependent insulinotropic polypeptide receptor (GIPR) expression in their somatotropinomas. Design, Setting, and Patients We performed combined molecular analyses, including array-comparative genomic hybridization, RNA/DNA fluorescence in situ hybridization, and RRBS DNA methylation analysis on 41 somatotropinoma samples from 38 patients with acromegaly and three sporadic giants. Ten patients displayed paradoxical GH responses to oral glucose. Results GIPR expression was detected in 13 samples (32%), including all 10 samples from patients with paradoxical GH responses. All GIPR-expressing somatotropinomas were negative for GNAS mutations. GIPR expression occurred through transcriptional activation of a single allele of the GIPR gene in all GIPR-expressing samples, except in two tetraploid samples, where expression occurred from two alleles per nucleus. In addition to extensive 19q duplications, we detected in four samples GIPR locus microamplifications in a certain proportion of nuclei. We identified an overall hypermethylator phenotype in GIPR-expressing samples compared with GNAS-mutated adenomas. In particular, we observed hypermethylation in the GIPR gene body, likely driving its ectopic expression. Conclusions We describe a distinct molecular subclass of somatotropinomas, clinically revealed by a paradoxical increase of GH to oral glucose related to pituitary GIPR expression. This ectopic GIPR expression occurred through hypomorphic transcriptional activation and is likely driven by GIPR gene microamplifications and DNA methylation abnormalities.

In X-linked hypophosphatemia (XLH), inherited loss-of-function mutations in the PHEX gene cause excess circulating levels of fibroblast growth factor 23 (FGF23), leading to lifelong renal phosphate wasting and hypophosphatemia. Adults with XLH present with chronic musculoskeletal pain and stiffness, short stature, lower limb deformities, fractures, and pseudofractures due to osteomalacia, accelerated osteoarthritis, dental abscesses, and enthesopathy. Burosumab, a fully human monoclonal antibody, binds and inhibits FGF23 to correct hypophosphatemia. This report summarizes results from a double-blind, placebo-controlled, phase 3 trial of burosumab in symptomatic adults with XLH. Participants with hypophosphatemia and pain were assigned 1:1 to burosumab 1 mg/kg (n = 68) or placebo (n = 66) subcutaneously every 4 weeks (Q4W) and were comparable at baseline. Across midpoints of dosing intervals, 94.1% of burosumab-treated participants attained mean serum phosphate concentration above the lower limit of normal compared with 7.6% of those receiving placebo (p0.001). Burosumab significantly reduced the Western Ontario and the McMaster Universities Osteoarthritis Index (WOMAC) stiffness subscale compared with placebo (least squares [LS] mean ± standard error [SE] difference, -8.1 ± 3.24; p = 0.012). Reductions in WOMAC physical function subscale (-4.9 ± 2.48; p = 0.048) and Brief Pain Inventory worst pain (-0.5 ± 0.28; p = 0.092) did not achieve statistical significance after Hochberg multiplicity adjustment. At week 24, 43.1% (burosumab) and 7.7% (placebo) of baseline active fractures were fully healed; the odds of healed fracture in the burosumab group was 16.8-fold greater than that in the placebo group (p0.001). Biochemical markers of bone formation and resorption increased significantly from baseline with burosumab treatment compared with placebo. The safety profile of burosumab was similar to placebo. There were no treatment-related serious adverse events or meaningful changes from baseline in serum or urine calcium, intact parathyroid hormone, or nephrocalcinosis. These data support the conclusion that burosumab is a novel therapeutic addressing an important medical need in adults with XLH.© 2018 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals, Inc.

Primary hyperparathyroidism (PHPT) is one of the most common endocrine disorders in the general population but is rarely diagnosed during pregnancy. Symptoms of gestational PHPT may be unrecognized, or masked by physiological changes in calcium homeostasis associated with pregnancy. Gestational PHPT may have severe consequences for both mother and fetus. However, nowadays, gestational PHPT is usually diagnosed in earlier stages and milder forms, with low complication rates. Treatment should be individually tailored according to gestational age, the severity of hypercalcemia, and the risk-benefit balance. The conservative approach is preferred in mild forms, whereas surgery, usually performed during the second trimester, is reserved for symptomatic hypercalcemic PHPT. Given the young age of the patients, genetic causes should be considered.

BACKGROUND: Increased secretion of growth hormone leads to gigantism in children and acromegaly in adults; the genetic causes of gigantism and acromegaly are poorly understood. METHODS: We performed clinical and genetic studies of samples obtained from 43 patients with gigantism and then sequenced an implicated gene in samples from 248 patients with acromegaly. RESULTS: We observed microduplication on chromosome Xq26.3 in samples from 13 patients with gigantism; of these samples, 4 were obtained from members of two unrelated kindreds, and 9 were from patients with sporadic cases. All the patients had disease onset during early childhood. Of the patients with gigantism who did not carry an Xq26.3 microduplication, none presented before the age of 5 years. Genomic characterization of the Xq26.3 region suggests that the microduplications are generated during chromosome replication and that they contain four protein-coding genes. Only one of these genes, GPR101, which encodes a G-protein-coupled receptor, was overexpressed in patients' pituitary lesions. We identified a recurrent GPR101 mutation (p.E308D) in 11 of 248 patients with acromegaly, with the mutation found mostly in tumors. When the mutation was transfected into rat GH3 cells, it led to increased release of growth hormone and proliferation of growth hormone-producing cells. CONCLUSIONS: We describe a pediatric disorder (which we have termed X-linked acrogigantism [X-LAG]) that is caused by an Xq26.3 genomic duplication and is characterized by early-onset gigantism resulting from an excess of growth hormone. Duplication of GPR101 probably causes X-LAG. We also found a recurrent mutation in GPR101 in some adults with acromegaly. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and others.).

International audience; Background: Patients with Cushing's syndrome have left ventricular (LV) hypertrophy and dysfunction on echocardiography, but echo-based measurements may have limited accuracy in obese patients. No data are available on right ventricular (RV) and left atrial (LA) size and function in these patients.Objectives: The objective of the study was to evaluate LV, RV, and LA structure and function in patients with Cushing's syndrome by means of cardiac magnetic resonance, currently the reference modality in assessment of cardiac geometry and function.Methods: Eighteen patients with active Cushing's syndrome and 18 volunteers matched for age, sex, and body mass index were studied by cardiac magnetic resonance. The imaging was repeated in the patients 6 months (range 2-12 mo) after the treatment of hypercortisolism.Results: Compared with controls, patients with Cushing's syndrome had lower LV, RV, and LA ejection fractions (P < .001 for all) and increased end-diastolic LV segmental thickness (P < .001). Treatment of hypercortisolism was associated with an improvement in ventricular and atrial systolic performance, as reflected by a 15% increase in the LV ejection fraction (P = .029), a 45% increase in the LA ejection fraction (P < .001), and an 11% increase in the RV ejection fraction (P = NS). After treatment, the LV mass index and end-diastolic LV mass to volume ratio decreased by 17% (P < .001) and 10% (P = .002), respectively. None of the patients had late gadolinium myocardial enhancement.Conclusion: Cushing's syndrome is associated with subclinical biventricular and LA systolic dysfunctions that are reversible after treatment. Despite skeletal muscle atrophy, Cushing's syndrome patients have an increased LV mass, reversible upon correction of hypercortisolism.

Pituitary adenomas are benign intracranial neoplasms that can result in morbidity owing to local invasion and/or excessive or deficient hormone production. The prevalence of symptomatic pituitary adenomas is approximately 1:1,000 in the general population. The vast majority of these tumours occur sporadically and are not part of syndromic disorders. However, germline mutations in genes known to predispose individuals to familial pituitary adenomas are found in a few patients with sporadic pituitary adenomas. Mutations in AIP (encoding aryl-hydrocarbon receptor-interacting protein) are the most frequently observed germline mutations. The prevalence of these mutations in patients with sporadic pituitary adenomas is ∼4%, but can increase to 8-20% in young adults with macroadenomas or gigantism, and also in children. Germline mutations in MEN1 (encoding menin) result in multiple endocrine neoplasia type 1 and are found in very young patients with isolated sporadic pituitary adenomas, which highlights the importance of the chromosome 11q13 locus in pituitary tumorigenesis. In this Review, we describe the clinical features of patients with sporadic pituitary adenomas that are associated with AIP or MEN1 mutations, and discuss the molecular mechanisms that might be involved in pituitary adenoma tumorigenesis. We also discuss genetic screening of patients with sporadic pituitary adenomas and investigations of relatives of these patients who also have the same genetic mutations.

International audience; GIP-dependent Cushing's syndrome is caused by ectopic expression of glucose-dependent insulinotropic polypeptide receptor (GIPR) in cortisol-producing adrenal adenomas or in bilateral macronodular adrenal hyperplasias. Molecular mechanisms leading to ectopic GIPR expression in adrenal tissue are not known. Here we performed molecular analyses on adrenocortical adenomas and bilateral macronodular adrenal hyperplasias obtained from 14 patients with GIP-dependent adrenal Cushing's syndrome and one patient with GIP-dependent aldosteronism. GIPR expression in all adenoma and hyperplasia samples occurred through transcriptional activation of a single allele of the GIPR gene. While no abnormality was detected in proximal GIPR promoter methylation, we identified somatic duplications in chromosome region 19q13.32 containing the GIPR locus in the adrenocortical lesions derived from 3 patients. In 2 adenoma samples, the duplicated 19q13.32 region was rearranged with other chromosome regions, whereas a single tissue sample with hyperplasia had a 19q duplication only. We demonstrated that juxtaposition with cis-acting regulatory sequences such as glucocorticoid response elements in the newly identified genomic environment drives abnormal expression of the translocated GIPR allele in adenoma cells. Altogether, our results provide insight into the molecular pathogenesis of GIP-dependent Cushing's syndrome, occurring through monoallelic transcriptional activation of GIPR driven in some adrenal lesions by structural variations.

Germline mutations in the aryl hydrocarbon receptor-interacting protein (AIP) gene predispose humans to pituitary adenomas through unknown molecular mechanisms. The best-known interacting partner of AIP is the aryl hydrocarbon receptor (AhR), a transcription factor that mediates the effects of xenobiotics implicated in carcinogenesis. As 75% of AIP mutations disrupt the physical and/or functional interaction with AhR, we postulated that the tumorigenic potential of AIP mutations might result from altered AhR signaling. We evaluated the impact of AIP mutations on the AhR signaling pathway, first in fibroblasts from AIP-mutated patients with pituitary adenomas, by comparison with fibroblasts from healthy subjects, then in transfected pituitary GH3 cells. The AIP protein level in mutated fibroblasts was about half of that in cells from healthy subjects, but AhR expression was unaffected. Gene expression analyses showed significant modifications in the expression of the AhR target genes CYP1B1 and AHRR in AIP-mutated fibroblasts, both before and after stimulation with the endogenous AhR ligand kynurenine. Kynurenine increased Cyp1b1 expression to a greater extent in GH3 cells overexpressing wild type compared with cells expressing mutant AIP. Knockdown of endogenous Aip in these cells attenuated Cyp1b1 induction by the AhR ligand. Both mutant AIP expression and knockdown of endogenous Aip affected the kynurenine-dependent GH secretion of GH3 cells. This study of human fibroblasts bearing endogenous heterozygous AIP mutations and transfected pituitary GH3 cells shows that AIP mutations affect the AIP protein level and alter AhR transcriptional activity in a gene- and tissue-dependent manner.

Hypercalciuria is frequent in patients with acromegaly, but it is unclear how GH/IGF-I regulate renal calcium handling. Elevated fasting plasma calcium levels despite increased glomerular filtration suggest enhanced renal calcium reabsorption.The aim of this study was to investigate the impact of acromegaly on phosphocalcium metabolism.We conducted a prospective sequential study at a tertiary referral medical center and clinical investigation center (www.ClinicalTrials.gov Identifier: NCT00531908).Sixteen consecutive patients (five females/11 males) with acromegaly received a single iv infusion of 25 mg of furosemide to induce an acute increase in calcium and magnesium delivery to distal tubular segments during a high-sodium diet with stable dietary calcium, magnesium, and phosphate intake.Baseline plasma and urine electrolytes, plasma calciotropic hormones, and furosemide-induced changes in the fractional excretion and tubular reabsorption of Na, Ca, and Mg were measured before and 6 months (range, 1-12) after effective treatment of acromegaly.Serum IGF-I concentrations normalized in all the patients after acromegaly treatment. Compared with controlled acromegaly, active acromegaly was associated with higher fasting plasma (P = 0.0002) and urinary calcium (P = 0.0003) levels, lower PTH levels (P = 0.0075), higher calcitriol levels (P = 0.0137), higher phosphatemia (P0.0001) and tubular phosphate reabsorption (P = 0.0002), and a lower calciuric (P = 0.0327) but not magnesiuric response to furosemide related to higher baseline and postfurosemide tubular calcium (P = 0.0034 and P = 0.0081, respectively), but not magnesium reabsorption.The IGF-I-mediated and PTH-independent increase in calcitriol synthesis in acromegaly is responsible for both absorptive hypercalciuria and increased fasting plasma calcium linked to enhanced distal tubular calcium reabsorption, as shown by the selectively diminished calciuric response to furosemide.

The ten previous years in terms of acromegaly treatment were essentially characterized by the experience accumulated with new formulations of somatostatin analogues or new drugs such GH-receptor antagonists recently available. Surgery remains the first-line treatment and its results did not change despite the generalization of endoscopy, which mainly seems to decrease local side-effects. The setting of radiotherapy was essentially modified by the increasing use of gamma-knife or stereotactic radiotherapy; however, their results are essentially the same as the classic fractionated, conventional radiotherapy and nobody knows if it will decrease the side-effects of this therapeutic modality. Nevertheless, thanks to a multistep therapeutic strategy, combining the different therapeutic modalities, it has become very rare for acromegaly not to be controlled in a patient.