Lysine vasopressin stimulation of cortisol secretion in patients with adrenocorticotropin-independent macronodular adrenal hyperplasia

High expression of adrenal P450 aromatase (CYP19A1) in association with ARMC5-primary bilateral macronodular adrenocortical hyperplasia

Primary bilateral macronodular adrenocortical hyperplasia (PBMAH) is a rare cause of ACTH-independent Cushing syndrome (CS), which has been associated with ectopic G-protein coupled receptors (GPCRs) in the adrenal cortex. We recently studied a 51-year-old male with PBMAH who presented with severe CS and hyperestronemia, manifesting clinically with a Cushingoid appearance, gynecomastia, and telangiectasias. Analysis of adrenal tissues following bilateral adrenalectomy showed high expression of P450 aromatase (CYP19A1). The patient carried a germline non-sense pathogenic variant in ARMC5 (p.R173*), with two independent somatic pathogenic variants identified in the right (p.S571*) and left (p.Q235*) adrenal tissues, respectively. The expression of ARMC5 was drastically decreased in the hyperplastic regions when compared to either the adjacent non-hyperplastic regions and samples from PBMAH without pathogenic variants in ARMC5. We found expression of CYP19A1 in other cases of PBMAH, although there were no differences in aromatase expression between ARMC5-mutant and ARMC5-non-mutant cases. We conclude that in select cases, PBMAH can be associated with aromatase expression resulting in elevated estrogens, irrespective of sex. Additionally, CYP19A1 expression does not appear to depend on the ARMC5 variant status.

Successful Treatment of Estrogen Excess in Primary Bilateral Macronodular Adrenocortical Hyperplasia with Leuprolide Acetate

Primary bilateral macronodular adrenocortical hyperplasia (PBMAH) is an uncommon cause of adrenal Cushing syndrome (CS) in which cortisol and occasionally other steroid hormones can be secreted under the influence of aberrantly expressed G-protein coupled receptors (GPCRs) in the adrenal cortex. We describe the unique case of a 64-year-old postmenopausal female with PBMAH whose adrenal lesions expressed luteinizing hormone receptors (LHr). She presented initially with CS and underwent right adrenalectomy; a few years later she presented with macromastia and mastodynia, possibly due to estrogen excess from her remaining left adrenocortical masses. Testing before and after treatment with quarterly leuprolide acetate therapy and immunohistochemistry on tissue and targeted sequencing of the genes of interest were performed. Tissue from the patient's right adrenal was tested for P450 aromatase (CYP19A1) and LHr expression; both were expressed throughout the hyperplastic cortex, although expression was more intense in the adenomatous areas. Targeted sequencing revealed a pathogenic PDE11A mutation, as well as variants in the ARMC5 and INHA genes. PDE11A expression was decreased in the adenoma but there was no loss of heterozygosity for the PDE11A locus. Because of the clinical presentation and LHr expression, quarterly leuprolide acetate therapy was started. Shortly after initiation of therapy, the patient reported decreased breast size and pain; she remains well controlled to date, after 10 years of treatment. This is the first description of a patient with PBMAH presenting with severe macromastia and mastodynia from what appears to be excess estrogen production from her adrenal tumor. The patient had a long-lasting response to chronic leuprolide acetate treatment, showing that drug therapy exploiting the aberrant receptor expression in PBMAH is possible even in the absence of cortisol overproduction.

Arginine vasopressin (AVP): a review of its historical perspectives, current research and multifunctional role in the hypothalamo-hypophysial system

INTRODUCTION

This publication reviews the function of arginine vasopressin and focuses on the morphologic and functional correlation between the hormone and its effect on stress, the hypophysial-adrenocortical axis, neuroimmune responses, renal function and corticotroph pituitary tumors.

MATERIALS AND METHODS

A literature review was performed using various search engines for information regarding the morphology and the multifunctional role of arginine vasopressin.

RESULTS

Although a large number of studies were published discussing these interactions, there are several important areas that are still obscure.

CONCLUSION

The questions of how does arginine vasopressin affect the morphology and function of these various areas, and how does the secretion of ACTH and adrenocortical hormones influence the morphology of arginine vasopressin-producing cells and their hormone secretion requires further investigation.

ARMC5 Mutations in a Large Cohort of Primary Macronodular Adrenal Hyperplasia: Clinical and Functional Consequences

CONTEXT

Primary bilateral macronodular adrenal hyperplasia (PBMAH) is a rare cause of primary adrenal Cushing's syndrome (CS). ARMC5 germline mutations have been identified recently in PBMAH.

OBJECTIVE

To determine the prevalence of ARMC5 mutations and analyze genotype-phenotype correlation in a large cohort of unrelated PBMAH patients with subclinical or clinical CS.

PATIENTS AND METHODS

ARMC5 was sequenced in 98 unrelated PBMAH index cases. PBMAH was identified by bilateral adrenal nodular enlargement on computed tomography scan. The effect on apoptosis of ARMC5 missense mutants was tested in H295R and HeLa cells. Clinical and hormonal data were collected including midnight and urinary free cortisol levels, ACTH, androgens, renin/aldosterone ratio, cortisol after overnight dexamethasone suppression test, cortisol and 17-hydroxyprogesterone after ACTH 1-24 stimulation and illegitimate receptor responses. Computed tomography and histological reports were analyzed.

RESULTS

ARMC5-damaging mutations were identified in 24 patients (26%). The missense mutants and the p.F700del deletion were unable to induce apoptosis in both H295R and HeLa cell lines, unlike the wild-type gene. ARMC5-mutated patients showed an overt CS more frequently, compared to wild-type patients: lower ACTH, higher midnight plasma cortisol, urinary free cortisol, and cortisol after dexamethasone suppression test (P = .003, .019, .006, and <.001, respectively). Adrenals of patients with mutations were bigger and had a higher number of nodules (P = .001 and <.001, respectively).

CONCLUSIONS

ARMC5 germline mutations are common in PBMAH. Index cases of mutation carriers show a more severe hypercortisolism and larger adrenals. ARMC5 genotyping may help to identify clinical forms of PBMAH better and may also allow earlier diagnosis of this disease.

A review of the nonpressor and nonantidiuretic actions of the hormone vasopressin

The pressor and antidiuretic actions of arginine vasopressin (AVP) have been well documented. This review focuses on the less widely appreciated actions of AVP which also have important physiologic functions and when better understood may provide important insights into common disease states. These actions include effects on pain perception and bone structure as well as important relationships to the varied components of metabolic syndrome. These include effects on blood glucose, lipid levels, and blood pressure. AVP may also play a role in the progression of chronic kidney disease and effect physiologic changes relating to aging, abnormal social behavior, and cognitive function. Important cellular responses including cell proliferation, inflammation, and control of infection and their relationship to AVP are described. Finally, the effects of AVP on hemostasis and the hypothalamic-pituitary-adrenal axis are noted. The goal of this summary of the various actions of AVP is to direct attention to the potential benefits of research in these underemphasized areas of importance.

Molecular and clinical evidence for an ARMC5 tumor syndrome: concurrent inactivating germline and somatic mutations are associated with both primary macronodular adrenal hyperplasia and meningioma

CONTEXT

Primary macronodular adrenal hyperplasia (PMAH) is a rare cause of Cushing's syndrome, which may present in the context of different familial multitumor syndromes. Heterozygous inactivating germline mutations of armadillo repeat containing 5 (ARMC5) have very recently been described as cause for sporadic PMAH. Whether this genetic condition also causes familial PMAH in association with other neoplasias is unclear.

OBJECTIVE

The aim of the present study was to delineate the molecular cause in a large family with PMAH and other neoplasias.

PATIENTS AND METHODS

Whole-genome sequencing and comprehensive clinical and biochemical phenotyping was performed in members of a PMAH affected family. Nodules derived from adrenal surgery and pancreatic and meningeal tumor tissue were analyzed for accompanying somatic mutations in the identified target genes.

RESULTS

PMAH presenting either as overt or subclinical Cushing's syndrome was accompanied by a heterozygous germline mutation in ARMC5 (p.A110fs*9) located on chromosome 16. Analysis of tumor tissue showed different somatic ARMC5 mutations in adrenal nodules supporting a second hit hypothesis with inactivation of a tumor suppressor gene. A damaging somatic ARMC5 mutation was also found in a concomitant meningioma (p.R502fs) but not in a pancreatic tumor, suggesting biallelic inactivation of ARMC5 as causal also for the intracranial meningioma.

CONCLUSIONS

Our analysis further confirms inherited inactivating ARMC5 mutations as a cause of familial PMAH and suggests an additional role for the development of concomitant intracranial meningiomas.

ACTH-independent macronodular adrenocortical hyperplasia reveals prevalent aberrant in vivo and in vitro responses to hormonal stimuli and coupling of arginine-vasopressin type 1a receptor to 11β-hydroxylase

Background

Adrenal Cushing’s syndrome caused by ACTH-independent macronodular adrenocortical hyperplasia (AIMAH) can be accompanied by aberrant responses to hormonal stimuli. We investigated the prevalence of adrenocortical reactions to these stimuli in a large cohort of AIMAH patients, both in vivo and in vitro.

Methods

In vivo cortisol responses to hormonal stimuli were studied in 35 patients with ACTH-independent bilateral adrenal enlargement and (sub-)clinical hypercortisolism. In vitro, the effects of these stimuli on cortisol secretion and steroidogenic enzyme mRNA expression were evaluated in cultured AIMAH and other adrenocortical cells. Arginine-vasopressin (AVP) receptor mRNA levels were determined in the adrenal tissues.

Results

Positive serum cortisol responses to stimuli were detected in 27/35 AIMAH patients tested, with multiple responses within individual patients occurring for up to four stimuli. AVP and metoclopramide were the most prevalent hormonal stimuli triggering positive responses in vivo. Catecholamines induced short-term cortisol production more often in AIMAH cultures compared to other adrenal cells. Short- and long-term incubation with AVP increased cortisol secretion in cultures of AIMAH cells. AVP also increased steroidogenic enzyme mRNA expression, among which an aberrant induction of CYP11B1. AVP type 1a receptor was the only AVPR expressed and levels were high in the AIMAH tissues. AVPR1A expression was related to the AVP-induced stimulation of CYP11B1.

Conclusions

Multiple hormonal signals can simultaneously induce hypercortisolism in AIMAH. AVP is the most prevalent eutopic signal and expression of its type 1a receptor was aberrantly linked to CYP11B1 expression.

Clinical and genetic heterogeneity, overlap with other tumor syndromes, and atypical glucocorticoid hormone secretion in adrenocorticotropin-independent macronodular adrenal hyperplasia compared with other adrenocortical tumors

OBJECTIVE

ACTH-independent macronodular adrenal hyperplasia (AIMAH) is often associated with subclinical cortisol secretion or atypical Cushing's syndrome (CS). We characterized a large series of patients of AIMAH and compared them with patients with other adrenocortical tumors.

DESIGN AND PATIENTS

We recruited 82 subjects with: 1) AIMAH (n = 16); 2) adrenocortical cortisol-producing adenoma with CS (n = 15); 3) aldosterone-producing adenoma (n = 19); and 4) single adenomas with clinically nonsignificant cortisol secretion (n = 32).

METHODS

Urinary free cortisol (UFC) and 17-hydroxycorticosteroid (17OHS) were collected at baseline and during dexamethasone testing; aberrant receptor responses was also sought by clinical testing and confirmed molecularly. Peripheral and/or tumor DNA was sequenced for candidate genes.

RESULTS

AIMAH patients had the highest 17OHS excretion, even when UFCs were within or close to the normal range. Aberrant receptor expression was highly prevalent. Histology showed at least two subtypes of AIMAH. For three patients with AIMAH, there was family history of CS; germline mutations were identified in three other patients in the genes for menin (one), fumarate hydratase (one), and adenomatosis polyposis coli (APC) (one); a PDE11A gene variant was found in another. One patient had a GNAS mutation in adrenal nodules only. There were no mutations in any of the tested genes in the patients of the other groups.

CONCLUSIONS

AIMAH is a clinically and genetically heterogeneous disorder that can be associated with various genetic defects and aberrant hormone receptors. It is frequently associated with atypical CS and increased 17OHS; UFCs and other measures of adrenocortical activity can be misleadingly normal.

A case of severe hypertension caused by ACTH-independent macronodular adrenal hyperplasia

This report describes a rare case of ACTH-independent macronodular adrenal hyperplasia (AIMAH) arisen with symptomatic severe hypertension and hypokaliemia. A 55-year-old man was admitted to hospital with a clinical picture characterized by several episodes of transient ischemic attacks (TIA) and right hemiplegia, related to severe arterial hypertension. Laboratory tests showed urinary levels of catecholamines, metanephrines and vanillylmandelic acid (VMA) in normal range; high urinary free cortisol excretion, elevated serum cortisol with loss of the circadian rhythm and low ACTH plasma levels. ACTH failed to respond to CRH administration. Serum cortisol levels were not modified after high doses of dexamethasone. MRI showed bilateral macronodular hyperplasia of adrenal glands, whereas pituitary-MRI did not show tumoral lesions. Therefore, ACTH-independent macronodular hyperplasia was suspected. Though obese, the patient had no typical Cushing habit, and symptomatic hypertension with hypokaliemia was the only clinical evidence for this rare kind of Cushing's syndrome. After obtaining a satisfactory control of blood pressure, the patient was successfully submitted to laparoscopic bilateral adrenalectomy and underwent complete clinical remission. The histology showed adrenal macronodular hyperplasia. During the twenty-four month follow-up, the patient had no further transient ischemic attacks or need of glucocorticoid replacement therapy and withdrew the antihypertensive drugs.