Loss of KDM1A in GIP-dependent primary bilateral macronodular adrenal hyperplasia with Cushing's syndrome: a multicentre, retrospective, cohort study

Corticotropin-releasing hormone test predicts the outcome of unilateral adrenalectomy in primary bilateral macronodular adrenal hyperplasia

PURPOSE

Primary bilateral adrenal hyperplasia (PBMAH) is associated with hypercortisolism and a heterogeneous clinical expression in terms of cortisol secretion and related comorbidities. Historically, treatment of choice was bilateral adrenalectomy (B-Adx); however, recent data suggest that unilateral adrenalectomy (U-Adx) may be an effective alternative. For the latter, factors predicting the postsurgical outcome (e.g., biochemical control) have not been identified yet.

METHODS

PBMAH patients undergoing U-Adx for overt Cushing's syndrome (CS) in two tertiary care centers were retrospectively analysed. Remission was defined as a normalization of urinary free cortisol (UFC) without the need for medical treatment. The potential of hCRH test as a predictor of U-Adx outcome was evaluated in a subgroup.

RESULTS

23 patients were evaluated (69% females, mean age 55 years). Remission rate after U-Adx was 74% at last follow up (median 115 months from UAdx). Before U-Adx, a positive ACTH response to hCRH (Δ%ACTH increase > 50% from baseline) was associated with higher remission rates.

CONCLUSIONS

Three of four patients with PBMAH are surgically cured with U-Adx. Pre-operative hCRH testing can be useful to predict long-term remission rates.

KDM1A genotyping and expression in 146 sporadic somatotroph pituitary adenomas

IMPORTANCE

A paradoxical increase of growth hormone (GH) following oral glucose load has been described in ∼30% of patients with acromegaly and has been related to the ectopic expression of the glucose-dependent insulinotropic polypeptide (GIP) receptor (GIPR) in somatotropinomas. Recently, we identified germline pathogenic variants and somatic loss of heterozygosity of lysine demethylase 1A (KDM1A) in patients with GIP-dependent primary bilateral macronodular adrenal hyperplasia with Cushing's syndrome. The ectopic expression of GIPR in both adrenal and pituitary lesions suggests a common molecular mechanism.

OBJECTIVE

We aimed to analyze KDM1A gene sequence and KDM1A and GIPR expressions in somatotroph pituitary adenomas.

SETTINGS

We conducted a cohort study at university hospitals in France and in Italy. We collected pituitary adenoma specimens from acromegalic patients who had undergone pituitary surgery. We performed targeted exome sequencing (gene panel analysis) and array-comparative genomic hybridization on somatic DNA derived from adenomas and performed droplet digital PCR on adenoma samples to quantify KDM1A and GIPR expressions.

RESULTS

One hundred and forty-six patients with sporadic acromegaly were studied; 72.6% presented unsuppressed classical GH response, whereas 27.4% displayed a paradoxical rise in GH after oral glucose load. We did not identify any pathogenic variant in the KDM1A gene in the adenomas of these patients. However, we identified a recurrent 1p deletion encompassing the KDM1A locus in 29 adenomas and observed a higher prevalence of paradoxical GH rise (P = .0166), lower KDM1A expression (4.47 ± 2.49 vs 8.56 ± 5.62, P < .0001), and higher GIPR expression (1.09 ± 0.92 vs 0.43 ± 0.51, P = .0012) in adenomas from patients with KDM1A haploinsufficiency compared with those with 2 KDM1A copies.

CONCLUSIONS AND RELEVANCE

Unlike in GIP-dependent primary bilateral macronodular adrenal hyperplasia, KDM1A genetic variations are not the cause of GIPR expression in somatotroph pituitary adenomas. Recurrent KDM1A haploinsufficiency, more frequently observed in GIPR-expressing adenomas, could be responsible for decreased KDM1A function resulting in transcriptional derepression on the GIPR locus.

Consensus statement by the French Society of Endocrinology (SFE) and French Society of Pediatric Endocrinology & Diabetology (SFEDP) for the diagnosis of Cushing's syndrome: Genetics of Cushing's syndrome

Cushing's syndrome is due to overproduction of cortisol, leading to abnormal and prolonged exposure to cortisol. The most common etiology is Cushing disease, while adrenal causes are rarer. Knowledge of the genetics of Cushing's syndrome, and particularly the adrenal causes, has improved considerably over the last 10 years, thanks in particular to technical advances in high-throughput sequencing. The present study, by a group of experts from the French Society of Endocrinology and the French Society of Pediatric Endocrinology and Diabetology, reviewed the literature on germline genetic alterations leading to a predisposition to develop Cushing's syndrome. The review led to a consensus statement on genetic screening for Cushing disease and adrenal Cushing's syndrome.

Cushing's syndrome

Endogenous Cushing's syndrome results from excess glucocorticoid secretion, which leads to a myriad of clinical manifestations, comorbidities, and increased mortality despite treatment. Molecular mechanisms and genetic alterations associated with different causes of Cushing's syndrome have been described in the last decade. Imaging modalities and biochemical testing have evolved; however, both the diagnosis and management of Cushing's syndrome remain challenging. Surgery is the preferred treatment for all causes, but medical therapy has markedly advanced, with new drug options becoming available. Nevertheless, several comorbidities remain even after patient remission, which can affect quality of life. Accurate and timely diagnosis and treatment are essential for mitigating chronic complications of excess glucocorticoids and improving patient quality of life. In this Seminar, we aim to update several important aspects of diagnosis, complications, and treatment of endogenous Cushing's syndrome of all causes.

The expanding incretin universe: from basic biology to clinical translation

Incretin hormones, principally glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1(GLP-1), potentiate meal-stimulated insulin secretion through direct (GIP + GLP-1) and indirect (GLP-1) actions on islet β-cells. GIP and GLP-1 also regulate glucagon secretion, through direct and indirect pathways. The incretin hormone receptors (GIPR and GLP-1R) are widely distributed beyond the pancreas, principally in the brain, cardiovascular and immune systems, gut and kidney, consistent with a broad array of extrapancreatic incretin actions. Notably, the glucoregulatory and anorectic activities of GIP and GLP-1 have supported development of incretin-based therapies for the treatment of type 2 diabetes and obesity. Here we review evolving concepts of incretin action, focusing predominantly on GLP-1, from discovery, to clinical proof of concept, to therapeutic outcomes. We identify established vs uncertain mechanisms of action, highlighting biology conserved across species, while illuminating areas of active investigation and uncertainty that require additional clarification.

Prevalence and clinical features of armadillo repeat-containing 5 mutations carriers in a single center cohort of patients with bilateral adrenal incidentalomas

OBJECTIVE

We aimed to evaluate the prevalence of armadillo repeat-containing 5 (ARMC5) genetic defects in our cohort of bilateral adrenal incidentaloma (BAI) patients and to evaluate the possible existence of genotype-phenotype correlations.

DESIGN

Cross-sectional study.

SETTING

Tertiary care center.

PARTICIPANTS

72 BAI patients.

MAIN OUTCOME MEASURE(S)

The following data have been collected: morning adrenocorticotropic hormone (ACTH) concentrations; cortisol levels after 1 mg overnight dexamethasone suppression test (F-1mgDST); urinary free cortisol (UFC) levels; diameter of the adrenal masses; and the association with overweight/obesity, arterial hypertension, diabetes mellitus, dyslipidemia, cardiovascular events, unrelated neoplasia, osteoporosis, thyroid nodular disease, and primary hyperparathyroidism. A search for ARMC5 germline and somatic pathogenic variants was performed in all patients and in the adrenal tissue of patients operated on, respectively.

RESULTS

The prevalence of germline ARMC5 pathogenic variants among patients with mild autonomous cortisol secretion (MACS+, defined as F-1mgDST > 1.8 µg/dL) was 18.8%. No germline pathogenic variants were detected in patients without MACS. Moreover, somatic ARMC5 pathogenic variants were also found in the adrenal tissue of six patients without germline ARMC5 variants. The F-1mgDST levels >5 µg/dL predicted with a poor sensitivity but a 90.5% specificity in identifying the presence of ARMC5 germline pathogenic variants. We did not find any clinical parameter predictive of the ARMC5 mutation presence.

CONCLUSIONS

In MACS+ BAI patients, germline ARMC5 gene pathogenic variants are frequent. Further studies are needed to elucidate the pathophysiological role of somatic ARMC5 pathogenic variants on adrenal tumor development in otherwise wild-type (WT) patients.

ARMC5-negative primary bilateral macronodular adrenal hyperplasia

A woman in her 60s with chronic fatigue, depressed mood and proximal muscle weakness was referred to our endocrinology department. Physical examination revealed facial plethora, atrophic skin and ankle oedema. Adjuvant blood and urine analyses indicated endogenous ACTH-independent Cushing syndrome. Abdominal imaging showed bilateral macronodular adrenals, measuring 58.9 × 29.7 mm on the right and 55.6 × 42.6 mm on the left. Primary bilateral macronodular adrenal hyperplasia was confirmed by pathology after bilateral adrenalectomy. Gradual mental and physical recovery was observed in the months following surgery. Genetic sequencing failed to reveal mutations in the ARMC5 gene.Cushing syndrome is a rare entity that should be suspected when typical clinical signs, including skin atrophy with ecchymosis, muscle weakness or coloured stretch marks, are present. Primary bilateral macronodular adrenal hyperplasia is an uncommon cause of endogenous Cushing syndrome. It is a benign condition characterised by adrenal macronodules exceeding 1 cm and hypercorticism.

The Methylation Analysis of the Glucose-Dependent Insulinotropic Polypeptide Receptor (GIPR) Locus in GH-Secreting Pituitary Adenomas

The glucose-dependent insulinotropic polypeptide receptor (GIPR) is aberrantly expressed in about one-third of GH-secreting pituitary adenomas (GH-PAs) and has been associated with a paradoxical increase of GH after a glucose load. The reason for such an overexpression has not yet been clarified. In this work, we aimed to evaluate whether locus-specific changes in DNA methylation patterns could contribute to this phenomenon. By cloning bisulfite-sequencing PCR, we compared the methylation pattern of the GIPR locus in GIPR-positive (GIPR⁺) and GIPR-negative (GIPR^-) GH-PAs. Then, to assess the correlation between Gipr expression and locus methylation, we induced global DNA methylation changes by treating the lactosomatotroph GH3 cells with 5-aza-2'-deoxycytidine. Differences in methylation levels were observed between GIPR⁺ and GIPR^- GH-PAs, both within the promoter (31.9% vs. 68.2%, p < 0.05) and at two gene body regions (GB_1 20.7% vs. 9.1%; GB_2 51.2% vs. 65.8%, p < 0.05). GH3 cells treated with 5-aza-2'-deoxycytidine showed a ~75% reduction in Gipr steady-state level, possibly associated with the observed decrease in CpGs methylation. These results indicate that epigenetic regulation affects GIPR expression in GH-PAs, even though this possibly represents only a part of a much more complex regulatory mechanism.

Primary bilateral macronodular adrenal hyperplasia: A series of 32 cases and literature review

Primary bilateral macronodular adrenal hyperplasia (PBMAH) accounts for <2% of cases of Cushing's syndrome. The majority of patients present with no obvious steroid excess it means with autonomous cortisol secretion (ACS). The classic treatment for patients with overt Cushing's syndrome is bilateral adrenalectomy, but unilateral resection of the larger adrenal gland can result in clinical and/or biochemical remission in >90% of cases, especially in cases of ACS. In this article, a series of 32 cases with PBMAH is described. Most of the cases of PBMAH had ACS, except for one case with overt Cushing's syndrome. A study of aberrant receptors was performed in six patients, being negative in three cases, positive in the metoclopramide test in two cases and positive in the metoclopramide test and in the mixed meal test in another patient. The patient with overt Cushing's syndrome was treated with adrenostatic therapy achieving biochemical control, while two patients with ACS underwent unilateral adrenalectomy with resection of the largest adrenal gland, demonstrating hypercortisolism remission and improvement of cardiovascular risk factors after surgery. This article describes a series of 32 cases of PBMAH and offers a comprehensive review of PBMAH.

Impact of Morphology in the Genotype and Phenotype Correlation of Bilateral Macronodular Adrenocortical Disease (BMAD): A Series of Clinicopathologically Well-Characterized 35 Cases

Bilateral macronodular adrenocortical disease (BMAD) is characterized by the development of adrenal macronodules resulting in a pituitary-ACTH independent Cushing's syndrome. Although there are important similarities observed between the rare microscopic descriptions of this disease, the small series published are not representative of the molecular and genetic heterogenicity recently described in BMAD. We analyzed the pathological features in a series of BMAD and determined if there is correlation between these criteria and the characteristics of the patients. Two pathologists reviewed the slides of 35 patients who underwent surgery for suspicion of BMAD in our center between 1998 and 2021. An unsupervised multiple factor analysis based on microscopic characteristics divided the cases into 4 subtypes according to the architecture of the macronodules (containing or not round fibrous septa) and the proportion of the different cell types: clear, eosinophilic compact, and oncocytic cells. The correlation study with genetic revealed subtype 1 and subtype 2 are associated with the presence of ARMC5 and KDM1A pathogenic variants, respectively. By immunohistochemistry, all cell types expressed CYP11B1 and HSD3B1. HSD3B2 staining was predominantly expressed by clear cells whereas CYP17A1 staining was predominant on compact eosinophilic cells. This partial expression of steroidogenic enzymes may explain the low efficiency of cortisol production in BMAD. In subtype 1, trabeculae of eosinophilic cylindrical cells expressed DAB2 but not CYP11B2. In subtype 2, KDM1A expression was weaker in nodule cells than in normal adrenal cells; alpha inhibin expression was strong in compact cells. This first microscopic description of a series of 35 BMAD reveals the existence of 4 histopathological subtypes, 2 of which are strongly correlated with the presence of known germline genetic alterations. This classification emphasizes that BMAD has heterogeneous pathological characteristics that correlate with some genetic alterations identified in patients.

New advances in endocrine hypertension: from genes to biomarkers

Hypertension (HT) is a major cardiovascular risk factor that affects 10% to 40% of the general population in an age-dependent manner. Detection of secondary forms of HT is particularly important because it allows the targeted management of the underlying disease. Among hypertensive patients, the prevalence of endocrine HT reaches up to 10%. Adrenal diseases are the most frequent cause of endocrine HT and are associated with excess production of mineralocorticoids (mainly primary aldosteronism), glucocorticoids (Cushing syndrome), and catecholamines (pheochromocytoma). In addition, a few rare diseases directly affecting the action of mineralocorticoids and glucocorticoids in the kidney also lead to endocrine HT. Over the past years, genomic and genetic studies have allowed improving our knowledge on the molecular mechanisms of endocrine HT. Those discoveries have opened new opportunities to transfer knowledge to clinical practice for better diagnosis and specific treatment of affected subjects. In this review, we describe the physiology of adrenal hormone biosynthesis and action, the clinical and biochemical characteristics of different forms of endocrine HT, and their underlying genetic defects. We discuss the impact of these discoveries on diagnosis and management of patients, as well as new perspectives related to the use of new biomarkers for improved patient care.

Endogenous Cushing's syndrome during pregnancy

Endogenous Cushing's syndrome (CS) is rare during pregnancy, probably because hypercortisolism induces anovulation and infertility. To date, slightly above 200 cases have been reported in the literature. The most frequent etiology of CS diagnosed during gestation is from primary adrenal causes, namely adrenal adenomas and an entity called pregnancy-induced CS. The latter can be secondary to the aberrant adrenal expression of luteinizing hormone/human chorionic gonadotropin receptor (LHCGR) in the adrenal lesions. Diagnosis of CS during pregnancy is extremely challenging, as a consequence of the physiologic hypercortisolism normally present during pregnancy. Assessment of excess cortisol production tests should be interpreted cautiously using adapted upper limits of normal criteria for pregnant patients and a high index of suspicion is required for diagnosis. Imaging is also limited due to high risk of radiation exposure with computed tomography and teratogenicity with contrast agents. The optimal treatment strategy is surgical resection of adrenal adenoma or pituitary adenoma, ideally before 24 weeks of gestation to reduce the risk of maternal and fetal complications. In mild cases, surgery can be postponed until after delivery and treatment should focus on controlling metabolic complications of hypercortisolism, such as hypertension and dysglycemia. Maternal and fetal outcomes of excess cortisol exposure, except fetal loss, are not readily improved by successful treatment of hypercortisolism.

HCG-responsive aldosteronoma with transient secretion during pregnancy confirmed through HCG-stimulated adrenal venous sampling

Primary aldosteronism can be regulated by the ectopic expression of G-protein coupled receptors in aldosteronomas or bilateral hyperplasias. We report a rare case of a young woman in whom 2 pregnancies were complicated by pre-eclampsia and 1 miscarriage. The transient primary aldosteronism during pregnancies suggested the possibility of HCG stimulated aberrant adrenal expression of LHCG receptor in her adrenal tissues. This was supported by increased aldosterone and renin suppression during 5-day HCG stimulation test outside of pregnancy. Following a second 5-day HCG stimulation test, bilateral simultaneous adrenal vein sampling identified a lateralized source of aldosterone from an 8 mm right adrenal nodule. A right laparoscopic adrenalectomy resulted in clinical and biochemical cure and allowed a further uneventful pregnancy a few years later. This case illustrates the indication to investigate for potential primary aldosteronism in woman with transient hypertension during pregnancy.

Clinical, pathophysiologic, genetic and therapeutic progress in Primary Bilateral Macronodular Adrenal Hyperplasia

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 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 20-25% 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 GIP-dependent PBMAH. Functional studies demonstrated that inactivation of KDM1A leads to GIP-receptor (GIPR) overexpression and over or down-regulation 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 co-morbidities 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 co-morbidities. 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.

A Novel ARMC5 Germline Variant in Primary Macronodular Adrenal Hyperplasia Using Whole-Exome Sequencing

Background: Primary macronodular adrenocortical hyperplasia (PMAH) is a rare form of adrenal Cushing’s syndrome with incomplete penetrance which may be sporadic or autosomal dominant. The inactivation of the ARMC5 gene, a potential tumor suppressor gene, is one of the associated causes of PMAH. This study aimed to identify the variant responsible for Iranian familial PMAH. Methods: The proband, a 44-year-old woman, was directed to whole-exome sequencing (WES) of the blood sample to discover a germline variant. In addition, the identified causative variant was confirmed and segregated in other and available unaffected family members. Results: The novel germline heterozygous missense variant, c.2105C>A in the ARMC5 gene, was found, and the same germline variant as the proband was confirmed in two affected sisters. This variant was detected in the brother of the proband with an asymptomatic condition and this considered because of incomplete penetrance and age-dependent appearance. The function of the ARMC5 protein would be damaged by the identified variant, according to in silico and computer analyses that followed. Conclusion: The new germline ARMC5 variation (c.2105C>A, (p. Ala702Glu)) was interpreted as a likely pathogenic variant based on ACMG and Sherloc standards. PMAH may be diagnosed early using genetic testing that shows inherited autosomal dominant mutations in the ARMC5 gene.

Diagnosis and management of hypertension in patients with Cushing's syndrome: a position statement and consensus of the Working Group on Endocrine Hypertension of the European Society of Hypertension

Endogenous/exogenous Cushing's syndrome is characterized by a cluster of systemic manifestations of hypercortisolism, which cause increased cardiovascular risk. Its biological basis is glucocorticoid excess, acting on various pathogenic processes inducing cardiovascular damage. Hypertension is a common feature in Cushing's syndrome and may persist after normalizing hormone excess and discontinuing steroid therapy. In endogenous Cushing's syndrome, the earlier the diagnosis the sooner management can be employed to offset the deleterious effects of excess cortisol. Such management includes combined treatments directed against the underlying cause and tailored antihypertensive drugs aimed at controlling the consequences of glucocorticoid excess. Experts on endocrine hypertension and members of the Working Group on Endocrine Hypertension of the European Society of Hypertension (ESH) prepared this Consensus document, which summarizes the current knowledge in epidemiology, genetics, diagnosis, and treatment of hypertension in Cushing's syndrome.

Primary bilateral macronodular adrenal hyperplasia: definitely a genetic disease

Primary bilateral macronodular adrenal hyperplasia (PBMAH) is an adrenal cause of Cushing syndrome. Nowadays, a PBMAH diagnosis is more frequent than previously, as a result of progress in the diagnostic methods for adrenal incidentalomas, which are widely available. Although some rare syndromic forms of PBMAH are known to be of genetic origin, non-syndromic forms of PBMAH have only been recognized as a genetic disease in the past 10 years. Genomics studies have highlighted the molecular heterogeneity of PBMAH and identified molecular subgroups, allowing improved understanding of the clinical heterogeneity of this disease. Furthermore, the generation of these subgroups permitted the identification of new genes responsible for PBMAH. Constitutive inactivating variants in ARMC5 and KDM1A are responsible for the development of distinct forms of PBMAH. To date, pathogenic variants of ARMC5 are responsible for 20-25% of PBMAH, whereas germline KDM1A alterations have been identified in >90% of PBMAH causing food-dependent Cushing syndrome. The identification of pathogenic variants in ARMC5 and KDM1A demonstrated that PBMAH, despite mostly being diagnosed in adults aged 45-60 years, is a genetic disorder. This Review summarizes the important progress made in the past 10 years in understanding the genetics of PBMAH, which have led to a better understanding of the pathophysiology, opening new clinical perspectives.

Current approach of primary bilateral adrenal hyperplasia

PURPOSE OF REVIEW

To discuss the most recent findings on the pathophysiology, the genetic and molecular causes of primary bilateral adrenal hyperplasia (PBAH). The diagnostic approach of patients with PBAH will also be presented in detail with an emphasis on the emerging diagnostic tools and finally, the treatment of PBAH will be discussed with an emphasis on the newest surgical and medical treatment approaches.

RECENT FINDINGS

PBAH is a highly heterogeneous condition mostly detected incidentally on abdominal imaging. Based on the size of the nodules, PBAH is subdivided into primary bilateral macronodular adrenal hyperplasia (PBMAH) and micronodular adrenal hyperplasia. A substantial proportion of patients with PBMAH harbor a germline mutation of the armadillo repeat containing 5 tumor suppression gene and therefore genetic testing is strongly recommended. Measurements of plasma or urinary multisteroid profiles show promising results in that PBMAH has a distinctive plasma steroid fingerprint that can help in diagnosis and subtyping of PBMAH. Finally, although surgery is the mainstay of treatment of patients with PBAH, medical therapy is increasingly emerging as an alternative option.

SUMMARY

PBAH is a poorly studied and therefore a challenging disease to diagnose and treat. Hopefully with these newest diagnostic and therapeutic tools, a more comprehensive approach will be adopted.

Salt Sensitivity of Blood Pressure and Aldosterone: Interaction Between the Lysine-specific Demethylase 1 Gene, Sex, and Age

CONTEXT

Salt sensitivity of blood pressure (SSBP) is associated with increased cardiovascular risk, especially in individuals of African descent, although the underlying mechanisms remain obscure. Lysine-specific demethylase 1 (LSD1) is a salt-sensitive epigenetic regulator associated with SSBP and aldosterone dysfunction. An LSD1 risk allele in humans is associated with SSBP and lower aldosterone levels in hypertensive individuals of African but not European descent. Heterozygous knockout LSD1 mice display SSBP and aldosterone dysregulation, but this effect is modified by age and biological sex. This might explain differences in cardiovascular risk with aging and biological sex in humans.

OBJECTIVE

This work aims to determine if LSD1 risk allele (rs587618) carriers of African descent display a sex-by-age interaction with SSBP and aldosterone regulation.

METHODS

We analyzed 297 individuals of African and European descent from the HyperPATH cohort. We performed multiple regression analyses for outcome variables related to SSBP and aldosterone.

RESULTS

LSD1 risk allele carriers of African (but not European) descent had greater SSBP than nonrisk homozygotes. Female LSD1 risk allele carriers of African descent had greater SSBP, mainly relationship-driven by women with low estrogen (postmenopausal). There was a statistically significant LSD1 genotype-sex interaction in aldosterone response to angiotensin II stimulation in individuals aged 50 years or younger, with female carriers displaying decreased aldosterone responsiveness.

CONCLUSION

SSBP associated with LSD1 risk allele status is driven by women with a depleted estrogen state. Mechanisms related to a resistance to develop SSBP in females are uncertain but may relate to an estrogen-modulating effect on mineralocorticoid receptor (MR) activation and/or LSD1 epigenetic regulation of the MR.

An Overview of the Heterogeneous Causes of Cushing’s Syndrome due to Primary Macronodular Adrenal Hyperplasia (PMAH)

Primary macronodular adrenal hyperplasia (PMAH) is considered a rare cause of adrenal Cushing syndrome, is pituitary ACTH-independent, generally results from bilateral adrenal macronodules (>1 cm), and is often associated with variable cortisol secretion, resulting in a heterogeneous clinical presentation. Recent advances in the molecular pathogenesis of PMAH have offered new insights into the comprehension of this heterogeneous and complex adrenal disorder. Different molecular mechanisms involving the actors of the cAMP/protein kinase A pathway have been implicated in the development of PMAH, including germline and/or somatic molecular defects such as hyperexpression of the G-protein aberrant receptors and pathogenic variants of MC2R, GNAS, PRKAR1A, and PDE11A. Nevertheless, since 2013, the ARMC5 gene is believed to be a major genetic cause of PMAH, accounting for more than 80% of the familial forms of PMAH and 30% of apparently sporadic cases, except in food-dependent Cushing syndrome in which ARMC5 is not involved. Recently, 2 independent groups have identified that the tumor suppressor gene KDM1A is responsible for PMAH associated specifically with food-dependent Cushing syndrome. Consequently, PMAH has been more frequently genetically associated than previously assumed. This review summarizes the most important aspects, including hormone secretion, clinical presentation, radiological imaging, and molecular mechanisms, involved in familial Cushing syndrome associated with PMAH.

Cushing´s syndrome due to bilateral adrenal cortical disease: Bilateral macronodular adrenal cortical disease and bilateral micronodular adrenal cortical disease

Cushing´s syndrome (CS) secondary to bilateral adrenal cortical disease may be caused by bilateral macronodular adrenal cortical disease (BMACD) or by bilateral micronodular adrenal cortical disease (miBACD). The size of adrenal nodules is a key factor for the differentiation between these two entities (>1cm, BMACD and <1cm; miBACD). BMACD can be associated with overt CS, but more commonly it presents with autonomous cortisol secretion (ACS). Surgical treatment of BMACD presenting with CS or with ACS and associated cardiometabolic comorbidities should be the resection of the largest adrenal gland, since it leads to hypercortisolism remission in up to 95% of the cases. Medical treatment focused on the blockade of aberrant receptors may lead to hypercortisolism control, although cortisol response is frequently transient. miBACD is mainly divided in primary pigmented nodular adrenocortical disease (PPNAD) and isolated micronodular adrenocortical disease (i-MAD). miBACD can present at an early age, representing one of the main causes of CS at a young age. The high-dose dexamethasone suppression test can be useful in identifying a paradoxical increase in 24h-urinary free cortisol, that is a quite specific in PPNAD. Bilateral adrenalectomy is generally the treatment of choice in patients with overt CS in miBACD, but unilateral adrenalectomy could be considered in cases with asymmetric disease and mild hypercortisolism. This article will discuss the clinical presentation, genetic background, hormonal and imaging features and treatment of the main causes of primary bilateral adrenal hyperplasia associated with hypercortisolism.