Abstract-Primary aldosteronism is the most common form of secondary hypertension. Mutations in the KCNJ5 gene have been described recently in aldosterone-producing adenomas (APAs). The aim of this study was to investigate the prevalence of KCNJ5 mutations in unselected patients with primary aldosteronism and their clinical, biological and molecular correlates. KCNJ5 sequencing was performed on somatic (APA, nϭ380) and peripheral (APA, nϭ344; bilateral adrenal hyperplasia, nϭ174) DNA of patients with primary aldosteronism, collected through the European Network for the Study of Adrenal Tumors. Transcriptome analysis was performed in 102 tumors. Somatic KCNJ5 mutations (p.Gly151Arg or p.Leu168Arg) were found in 34% (129 of 380) of APA. They were significantly more prevalent in females (49%) than males (19%; PϽ10 Ϫ3) and in younger patients (42.1Ϯ1.0 versus 47.6Ϯ0.7 years; PϽ10 Ϫ3 ) and were associated with higher preoperative aldosterone levels (455Ϯ26 versus 376Ϯ17 ng/L; Pϭ0.012) but not with therapeutic outcome after surgery. Germline KCNJ5 mutations were found neither in patients with APA nor those with bilateral adrenal hyperplasia. Somatic KCNJ5 mutations were specific for APA, because they were not identified in 25 peritumoral adrenal tissues or 16 cortisol-producing adenomas. Hierarchical clustering of transcriptome profiles showed that APAs with p.Gly151Arg or p.Leu168Arg mutations were indistinguishable from tumors without KCNJ5 mutations. In conclusion, although a large proportion of sporadic APAs harbors somatic KCNJ5 mutations, germline mutations are not similarly causative for bilateral adrenal hyperplasia. KCNJ5 mutation carriers are more likely to be females; younger age and higher aldosterone levels at diagnosis suggest that KCNJ5 mutations may be associated with a more florid phenotype of primary aldosteronism. H ypertension is a major cardiovascular risk factor that affects between 10% and 40% of the population in industrialized countries. Detection of secondary forms of hypertension is particularly important because it allows for the targeted management of the underlying disease. Primary aldosteronism (PA) is the most common form of secondary hypertension, with an estimated prevalence between 6% and 12% of hypertensives and as high as 20% in patients with resistant hypertension. 1-5 PA occurs as the result of a dysregulation of the mechanisms controlling adrenal aldosterone production, ultimately leading to hypertension with low plasma renin and elevated aldosterone sometimes associated with hypokalemia. Among subtypes of PA, aldosteroneproducing adenoma (APA) and bilateral adrenal hyperplasia (BAH; also known as idiopathic hyperaldosteronism) together account for Ϸ95% of cases. [1][2][3] Aldosterone production from the adrenal zona glomerulosa is tightly controlled to maintain electrolyte and fluid homeostasis by the kidney. Thus, the two most important physiological stimuli of aldosterone secretion are angiotensin II and serum potassium. Glomerulosa cell membrane depolarization leads to openi...
P rimary aldosteronism (PA) is a common curable cause of high blood pressure (BP).1 PA is of peculiar interest because the excess aldosterone secretion is held to be autonomous from angiotensin II, which allows elucidating the cardiovascular effects of excess aldosterone without the confounding effects of excess angiotensin II. Moreover, as the excess of aldosterone is cured with adrenalectomy in practically all patients, 2 causation between aldosterone excess and the cardiovascular changes could be inferred. However, whether surgery or pharmacological blockade of the mineralocorticoid receptor (MR) warrant cure of high BP and regression of cardiovascular damage, and of cardiac remodeling, at long term remains unclear because limited data exist. 3,4 The adaption of the left ventricle (LV) to the increased afterload of patients with high BP involves development of hypertrophy (LVH), which predicts cardiovascular events and death, 5 and when regressed improved prognosis. 6 In the complex interplay of hemodynamic, genetic, and endocrine-paracrine factors that underlie development of LVH aldosterone plays a pivotal role. [7][8][9] In the setting of a high sodium intake, this major effector of the system causes LVH, transcription of collagen type I and III genes, 10 and promotes fibroblasts proliferation, oxidative stress, and inflammation, 11 in part, by potentiating the effects of angiotensin II on AT-1 receptors.12-15 These actions, alongside the effects of the steroid on pre-and after-load, are held to cause inflammation and fibrosis, which contribute to worsening prognosis of patients with hyperaldosteronism, 8,16 and can explain the survival benefit conferred by MR antagonists to optimally treated patients with LV systolic dysfunction. 17,18 Compared with BP-matched primary (essential) hypertensive patients, those with PA have an excess LVH and a LV mass inappropriately high for the degree of LV workload and BP elevation. [2][3][4]9,[19][20][21][22][23][24][25][26][27][28] Cardiac fibrosis with ensuing altered LV diastolic dysfunction can lead to left atrium dilatation and increased risk of atrial fibrillation (AF) 7,8,29 ; whether these changes regress with specific treatment for PA remains uncertain. 3,4,19,20,26 We, therefore, set out to prospectively investigate the long-term effects of correction of hyperaldosteronism on BP, LV mass, and cardiovascular events in a large cohort of patients with PA.Abstract-Primary aldosteronism (PA), a common cause of high blood pressure (BP), induces left ventricular (LV) hypertrophy and an excess rate of cardiovascular events. Whether its treatment provides long-term cure of hypertension and regression of cardiovascular damage remains uncertain. To the aim of assessing the effect of treatment of PA on BP and LV changes, we prospectively recruited 323 patients in a long-term follow-up study entailing serial echocardiography evaluations. Of them, 180 had PA and were assigned to either adrenalectomy (n=110) or medical therapy (n=70)
KCNJ5 mutations are prevalent in APA, and our data suggest that these mutations increase expression of CYP11B2 and NR4A2, thus increasing aldosterone production.
In CHF patients TSH levels even slightly above normal range are independently associated with a greater likelihood of heart failure progression. This supports the need for prospective studies aimed at clarifying the most appropriate therapeutic approach to sub-clinical hypothyroidism in such patients.
Hypertension is one of the most distinguishing features of endogenous Cushing’s syndrome (CS), as it is present in about 80% of adult patients whereas in children its prevalence is about 47%. Hypertension in CS is significantly correlated with the duration of hypercortisolism and results from the interplay between several pathophysiological mechanisms regulating plasma volume, peripheral vascular resistance and cardiac output, all of which are increased in this state. Glucocorticoids cause hypertension through several mechanisms: their intrinsic mineralocorticoid activity; through activation of the renin-angiotensin system; by enhancement of vasoactive substances, and by causing suppression of the vasodilatory systems. In addition, glucocorticoids may exert some hypertensive effects on cardiovascular regulation through the CNS via both glucocorticoid and mineralocorticoid receptors. Hypertension in CS usually resolves with surgical removal of the tumor, but some patients require pharmacological antihypertensive treatment both pre- and postoperatively. Thiazides and furosemide should be avoided, while adrenergic blockade and calcium channel antagonists are usually ineffective. Mineralocorticoid receptor antagonists, Ang II blockers and ACE inhibitors are good anti-hypertensive options; PPAR-γ agonists may help in many aspects of the insulin resistance syndrome. The relatively selective glucocorticoid receptor antagonist Mifepristone (RU 486) could reduce blood pressure in patients with CS. Neuromodulatory agents such as the serotonin inhibitors cyproheptadine and ritanserin, valproid acid, dopamine agonists, somatostatin analogs may occasionally be effective, as well as drugs acting directly at the adrenal levels, such as Ketoconazole and aminoglutetimide or even opDDD. Treating hypertension in CS remains a difficult task and a big challenge, in order to decrease the morbidity and mortality associated with the disease.
Treatment options are insufficient in patients with adrenocortical carcinoma (ACC). Based on the efficacy of sorafenib, a tyrosine kinase inhibitor, and everolimus, an inhibitor of the mammalian target of rapamycin in tumors of different histotype, we aimed at testing these drugs in adrenocortical cancer models. The expression of vascular endothelial growth factor and its receptors (VEGFR1-2) was studied in 18 ACCs, 33 aldosterone-producing adenomas, 12 cortisol-producing adenomas, and six normal adrenal cortex by real-time PCR and immunohistochemistry and by immunoblotting in SW13 and H295R cancer cell lines. The effects of sorafenib and everolimus, alone or in combination, were tested on primary adrenocortical cultures and SW13 and H295R cells by evaluating cell viability and apoptosis in vitro and tumor growth inhibition of tumor cell line xenografts in immunodeficient mice in vivo. VEGF and VEGFR1-2 were detected in all samples and appeared over-expressed in two-thirds of ACC specimens. Dose-dependent inhibition of cell viability was observed particularly in SW13 cells after 24 h treatment with either drug; drug combination produced markedly synergistic growth inhibition. Increasing apoptosis was observed in tumor cells treated with the drugs, particularly with sorafenib. Finally, a significant mass reduction and increased survival were observed in SW13 xenograft model undergoing treatment with the drugs in combination. Our data suggest that an autocrine VEGF loop may exist within ACC. Furthermore, a combination of molecularly targeted agents may have both antiangiogenic and direct antitumor effects and thus could represent a new therapeutic tool for the treatment of ACC.
Compared to the wild-type APA patients those with KCNJ5 mutations showed more prominent cardiovascular damage. Notwithstanding this, their chances of being cured from the hyperaldosteronism and the high BP, and of regression of left ventricular hypertrophy after adrenalectomy, were not compromised by the presence of these mutations.
Background Autoantibodies to the angiotensin II type 1 receptor (AT1R) have been reported in patients with primary aldosteronism including aldosterone producing adenoma (APA) and idiopathic adrenal hyperplasia (IAH). Methods and Results Sera from 25 primary aldosteronism subjects (12 with IAH and 13 with APA) and 15 normotensive control subjects were assayed for AT1R autoantibodies by ELISA and an AT1R-transfected cell-based bioassay. Nine of 12 IAH subjects (75%) and 6 of 13 APA subjects (46%) were positive for AT1R autoantibodies in the bioactivity assay. The mean AT1R autoantibody activity for the IAH and APA subjects was significantly greater than controls (P<0.001 and P<0.01, respectively), and this in vitro activity was suppressed by the AT1R blocker losartan. None of the controls had significant AT1R autoantibody activity. ELISA values were less sensitive but were positive in some subjects with IAH and APA. The mean arterial pressure of these primary aldosteronism subjects correlated modestly with AT1R autoantibody activity. Conclusion These data confirm the presence of active AT1R autoantibodies in a high percentage of subjects with primary aldosteronism irrespective of their underlying etiology. These observations have both pathophysiological and clinical implications.
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