Glucocorticoid-remediable Aldosteronism Research Articles

FRI190 Catching A Chimera: A Case Of Suspected Glucocorticoid Remediable Aldosteronism

Abstract Disclosure: A. Khan: None. B. Ramchandani: None. H.B. Aftab: None. Introduction: Familial hyperaldosteronism type 1 (FH-I), also known as glucocorticoid remediable aldosteronism (GRA) is responsible for 1% of cases of primary aldosteronism (PA). It is caused by a chimeric fusion of the CYP11B2 and CYP11B1 genes resulting in ACTH-sensitive aldosterone production. We describe a case of suspected GRA and outline the diagnosis of this rare condition. Case. A 52-year-old female with history of type 2 diabetes mellitus, obesity, sleep apnea, SVT with ablation presented with long-standing history of resistant hypertension (HTN). HTN was diagnosed in her late twenties. She was previously trialed on eight different classes of antihypertensive medications excluding mineralocorticoid antagonists or potassium-sparing diuretics but HTN remained uncontrolled. Current regimen included hydralazine, nebivolol, and furosemide. Her sister had HTN diagnosed in her forties, a nephew with HTN diagnosed in his early twenties and mother with HTN with unclear age of diagnosis. Her systolic and diastolic BP averaged 150 mmHg and 90 mmHg, respectively, on both home and clinic monitoring. Physical examination was significant for mild cushingoid appearance. Screening tests for pheochromocytoma and hypercortisolism were normal. Plasma aldosterone concentration (PAC) was noted to be at 14.4 ng/dl (<39.2) with a plasma renin activity (PRA) of <0.6 ng/mL/h (2.9 - 10.8), with aldosterone to renin ratio (ARR) of 24. Repeat testing showed PAC of 15.1 ng/dl, PRA<0.6 ng/ml/hr (ARR: 25.1) with potassium of 3.3 mmol/L (3.5 -5.1). PAC levels remained unsuppressed above 10 ng/dL following four-hour, seated, 2 L IV saline suppression test with serum potassium of 3.5 mmol/L. CT abdomen showed normal appearance of the adrenal glands. Given early age of onset of HTN and strong family history, 3-day dexamethasone test was performed using 1 mg oral dexamethasone every 12 hours following which PAC suppressed to <1 ng/dl. Patient was started on spironolactone 25 mg twice daily and at the time of writing is awaiting genetic testing to confirm the diagnosis of GRA. Discussion: GRA is a rare subtype of PA which has an increased risk of cardiovascular and cerebrovascular complications. Our case highlights the importance of screening for GRA in patients who have a personal and/or family history of early onset HTN who have screened positive for PA. Genetic testing for chimeric CYP11B1/B2 gene is the confirmatory step of diagnosis, however, a 3-day dexamethasone suppression test can be used to screen for GRA with a high sensitivity. Elevated levels of urine 18-hydroxycortisol and 18-oxocortisol are also noted but these are not widely available tests. Treatment of GRA is with medical management only; since surgical intervention is not required; proper diagnosis can also save the patient from unnecessary and invasive tests such as adrenal vein sampling. Presentation: Friday, June 16, 2023

FRI128 Hiding In Plain Sight: Late Diagnosis Of Primary Hyperaldosteronism In Patient With Atypical Presentation

Abstract Disclosure: R.A. Zielinski: None. A. Syeda: None. B. Esayag-Tendler: None. Background: Primary hyperaldosteronism (PHA) can go undiagnosed in patients with primary hypertension without hypokalemia and increased plasma aldosterone concentration (PAC). Case: The patient is a 72-year-old male with a history of hypertension (HTN) diagnosed at age 55 who presented to the endocrinology clinic for further evaluation. He was asymptomatic. His antihypertensive regimen included atenolol 25 mg daily and amlodipine-benazepril 10-40 mg daily. Blood pressure (BP) was well-controlled with a goal BP under 130/80 mm Hg. Physical exam was without AV nicking in a limited retina exam, no abdominal tenderness, and no peripheral edema. Family history is notable for HTN in his father and HTN complicated by stroke in a sister and a brother, all diagnosed at an older age. Labs done 5 years prior showed potassium (K) of 4.3 mmol/L [3.6 - 5.1 mmol/L], PAC of 3.2 ng/dl [upright 4.0 - 31.0 ng/dl], and plasma renin activity (PRA) of 0.1 ng/ml/hr [upright 0.5-4.0 ng/ml/hr]. More recent labs showed K of 3.8 mmol/L, PAC of 21.5 ng/dl and PRA of 0.3 ng/ml/hr. Repeat labs 6 months later showed K of 3.4 mmol/L, PAC of 15 ng/dL and PRA of 0.2 ng/mL/hr. A 3-day dexamethasone suppression test was performed to exclude familial hyperaldosteronism or glucocorticoid remediable aldosteronism. Following the test, K was 3.6 mmol/L, PAC was 11.3 ng/dl, and cortisol was undetectable. CT abdomen showed bilateral nodular thickening of the adrenal glands without a distinct adenoma. Adrenal venous sampling was done before and after ACTH stimulation. Prior to ACTH stimulation, the mean ratio of the dominant adrenal aldosterone concentration corrected with cortisol from left to right was 1.32. Following ACTH stimulation, the ratio was 2.79. A ratio greater than 4 is consistent with a good outcome after adrenalectomy. Hence, it was decided to pursue medical management. The cause of our patient’s primary hyperaldosteronism is likely due to bilateral idiopathic hyperplasia. He was started on eplerenone 25 mg twice daily and salt restriction with a goal of increasing the PRA above 1 ng/ml/hr. Discussion and Conclusion: It was initially thought that PHA represents 1% of all patients with primary HTN. However, more recent studies indicate that the prevalence is significantly higher. Additionally, the PAC in patients with PHA can fluctuate and patients can present with normokalemia, making the diagnosis more difficult to establish. It is an important diagnosis to establish and treat appropriately because there is a higher risk of cardiovascular morbidity and mortality in patients with PHA compared to patients with primary HTN. Presentation: Friday, June 16, 2023

FRI157 Systematic Germline Genetic Analysis In A Cohort Of Adults With Primary Aldosteronism And Hypertension Onset ≤35 yo : Low Yield Of Genetic Pathogenic Variants

Abstract Disclosure: S. Parisien-La Salle: None. D. Nadine: None. Z. El-Haffaf: None. A. Lacroix: None. I. Bourdeau: None. Introduction: Primary aldosteronism (PA) is a common but underdiagnosed cause of hypertension. Although most cases are sporadic, up to 5% of patients have a familial form of PA. Current guidelines recommend germline genetic analysis in patients who present PA < 20 yo or have a family history of PA. As PA is underdiagnosed, we hypothesized that some patients with PA do not undergo germline genetic screening since familial history of PA is unrecognized. Objective: To evaluate the yield of systematic germline genetic analysis for familial PA in patients with PA, hypertension detection ≤ 35 yo and a family history of hypertension. Methods: From 2012-2022, patients diagnosed with PA (positive ARR and confirmatory testing), hypertension onset ≤ 35 yo and a family history of hypertension were offered genetic counselling for germline screening for known familial causes of PA. After informed consent, patients underwent germline analysis for the chimeric gene CYP11B2/CYP11B1 (Ruhr University Bochum, Germany) and a multigene panel including KCNJ5, CACNA1D, CACNA1H and CLCN2 genes (Fulgent, CA). Results: Twenty-five patients consented for genetic analysis. Thirteen patients (52%) were female. In regards to ethnic origin, 52% were French Canadians, 24% African-Americans and the other 24% was split between Asian, European and Middle Eastern descent. The mean age at diagnosis of hypertension was 28.3 yo and 39.7 yo at PA diagnosis. At PA diagnosis, 91.3% (21/23) had previous hypokalemia and 12% (3/25) a cortisol co-secretion (1 mg dexamethasone test> 50 nmol/L). Approximately 13% were on one hypertension drug, 30% on two, 26% on three, 26% on four and 5% were on five medications. Comobordities included: 8% atrial fibrillation, 20% obstructive sleep apnea and 4% coronary heart disease. All patients had a family history of hypertension, 5 patients (20%) had a family history of stroke, and 1 patient (4%) had a family history of PA. Of the patients who had already undergone adrenal vein sampling (n=22), 68.2% (15/22) underwent an adrenalectomy for lateralised aldosterone secretion and 31.8% (7/22) were treated with medical therapy for bilateral disease. None of the 24 patients who underwent testing for glucocorticoid-remediable aldosteronism were found to have the chimeric gene CYP11B2/CYP11B1. Twenty-three patients underwent the multigene panel and no pathogenic variants were identified. However, 4/23 (17,4%) patients carried a variant of unknown significance (VUS) in CACNA1H or CLCN2 genes (CACNA1H c.1315C>T(p.Arg439Cys),CACNA1H c.3868G>A(p.Val1290Ile),CACNA1H c.1939G>A (p.Gly647Ser), CLCN2 c.2402C>T, (p.Thr801Ile)). Conclusion: Systematic germline genetic testing for familial PA in this cohort of patients with PA, hypertension diagnosis ≤ 35 yo and a family history of hypertension did not yield positive results. Although PA is an underdiagnosed disease, familial forms remain very rare. Presentation: Friday, June 16, 2023

Seroprevalence of Toxoplasma gondii and associated alterations in hematology and serum biochemistry of one-humped camels (Camelus dromedarius) in Pakistan.

Background and Aim:Toxoplasma gondii is an intracellular protozoan that infects humans and animals. This study aimed to estimate the seroprevalence of T. gondii and the associated alterations in hematology and serum biochemistry of one-humped camels (Camelus dromedarius) in Mianwali district, Pakistan.Materials and Methods:A total of 350 blood samples were obtained from male and female camels of different ages (≤3 years old, 4-6 years old, and ≥7 years old). To validate T. gondii antibodies, the collected samples were subjected to indirect enzyme-linked immunosorbent assay using purified recombinant micronemal protein 3 as an antibody catching antigen.Results:The prevalence of T. gondii was 50.2% higher in male camels than in female camels (16.5%) (p<0.001). Furthermore, the prevalence of T. gondii in camels was directly proportional to age (p<0.001). It was 63.33% (57/90) in camels of ≥7 years of age, 32.54% in 4-6 years old age group, and 23.08% in ≤3 years old age group. The hematological analysis of infected camels revealed a significant increase in the values of glucocorticoid-remediable aldosteronism, lymphocyte percentage, monocyte percentage (MONO%), corpuscular hemoglobin (MCH), and procalcitonin. Furthermore, substantially higher levels of liver enzymes alanine aminotransferase, aspartate aminotransferase, and the macro-mineral potassium were found in the serum of T. gondii-infected camels.Conclusion:The seropositivity of T. gondii is directly associated with the age and sex of camels, which may be considered as potential risk factors. Furthermore, T. gondii infection directly impacts the hemato-biochemistry of infected camels.

Characteristics and Outcomes in Primary Aldosteronism Patients Harboring Glucocorticoid-Remediable Aldosteronism.

The clinical characteristics and surgical prognosis of glucocorticoid-remediable aldosteronism (GRA, also known as familial hyperaldosteronism type 1, FH-I) have not been widely studied. Using data from the Taiwan Primary Aldosteronism Investigation (TAIPAI) registry retrospectively, we describe the associated clinical factors for GRA and clinical predictors of surgical outcomes among identified GRA patients. We found 79 GRA-positive (51.2 ± 13.8 years; women 39 (49.4%)) and 114 GRA-negative primary aldosteronism (PA) patients matched with age, gender, and body mass index. Lower plasma aldosterone concentrations (PACs) and aldosterone-renin ratios were found among GRA-positive individuals. Multivariable logistic regression demonstrated that a PAC ≤ 40 ng/dL could predict concealed GRA individuals (OR 0.523, p = 0.037). Low serum potassium (OR 0.285, p = 0.008), but not the presence of GRA, was associated with hypertension-remission. Of note, PRA (OR 11.645, p = 0.045) and hypokalemia (OR 0.133, p = 0.048) were associated with hypertension-remission in GRA patients. Unilateral primary aldosteronism patients harboring concomitant GRA were not associated with inferior hypertension-remission after an adrenalectomy. Low serum potassium and high PRA were positively associated with hypertension-remission in GRA patients.

Aldosterone and Primary Aldosteronism: Star Performers in Hypertension Research

Aldosterone and Primary Aldosteronism: Star Performers in Hypertension Research

Resistant Hypertension Due to Familial Hyperaldosteronism Type III: First Report From Indian Sub-Continent

Background: Familial hyperaldosteronism type III (FH-III) is caused by germline mutations in KCNJ5 gene. FH-III presents with phenotypic variability from spironolactone-responsive hypertension to massive adrenal hyperplasia requiring bilateral adrenalectomy. Till date, seven different pathogenic mutations in KCNJ5 gene have been identified. Here we describe a sporadic FH-III case, due to a Gly151Arg mutation, first from Indian subcontinent, presenting with extremely high plasma aldosterone concentration (PAC) values, further expanding our knowledge of this rare condition. Clinical Case: A 24-year-old female, symptomatic since age of 5 years with periodic limb weakness and gradual increase in frequency of episodes over the years. Her blood pressure (BP) was recorded for first time at 9 years of age, and it was 170/110 mm Hg. On evaluation at this time, PAC was highly elevated at 1007 ng/dL and plasma renin activity (PRA) was suppressed at 0.04 ng/ml/h with aldosterone renin ratio (ARR) of 25,175 ng/dL per ng/mL/h (>20 suggestive of primary aldosteronism). CT scan demonstrated mild enlargement of bilateral adrenal glands. A presumptive diagnosis of Glucocorticoid-remediable aldosteronism was made. She was started on dexamethasone, spironolactone and nifedipine but was not improved. Dexamethasone was stopped after 1 year of initiation. Before presenting to our referral center in 2018, she was having uncontrolled hypertension with recurrent episodes of hypokalemic paralysis. She was on maximal doses on four antihypertensive agents, further increased to six agents (including spironolactone 100 mg BD), and potassium chloride supplementation (120 mEq/day). Despite this, she had a serum potassium of 2.6 mEq/L. Her biochemical investigations demonstrated that PAC was 2070 ng/dL, direct renin concentration (DRC) was 2.35 µIU/mL (PRA 0.2 ng/ml/h) and ARR was 880.9 ng/dL per µIU/mL. CT scan revealed massive bilateral adrenal hyperplasia. Genetic analysis by whole exome sequencing detected KCNJ5 (p.Gly151Arg) mutation, confirming the diagnosis of FH-III. She was subjected to bilateral adrenalectomy and she became normokalemic. Dramatic reduction in antihypertensives with BP control achieved only on amlodipine post-operatively. Genetic testing of family members was not done but they were normotensive and normokalemic. Histopathological examination revealed bilateral adrenal hyperplasia. PAC levels up to 297 ng/dL have been described previously in FH-III but our patient had exceedingly high-level of 2070 ng/dL. Conclusion: This case demonstrates florid clinical and biochemical manifestations of FH-III and gradual worsening of symptoms, consistent with progression of disease with age. It illustrates that proper investigations and treatment can lead to remission of symptoms. Further studies are warranted to elucidate the full clinical and biochemical spectrum of FH-III.

GRAde: a long-read sequencing approach to efficiently identifying the CYP11B1/CYP11B2 chimeric form in patients with glucocorticoid-remediable aldosteronism

BackgroundGlucocorticoid-remediable aldosteronism (GRA) is a form of heritable hypertension caused by a chimeric fusion resulting from unequal crossing over between 11β‐hydroxylase (CYP11B1) and aldosterone synthase (CYP11B2), which are two genes with similar sequences. Different crossover patterns of the CYP11B1 and CYP11B2 chimeric genes may be associated with a variety of clinical presentations. It is therefore necessary to develop an efficient approach for identifying the differences between the hybrid genes of a patient with GRA.ResultsWe developed a long-read analysis pipeline named GRAde (GRA deciphering), which utilizes the nonidentical bases in the CYP11B1 and CYP11B2 genomic sequences to identify and visualize the chimeric form. We sequenced the polymerase chain reaction (PCR) products of the CYP11B1/CYP11B2 chimeric gene from 36 patients with GRA using the Nanopore MinION device and analyzed the sequences using GRAde. Crossover events were identified for 30 out of the 36 samples. The crossover sites appeared in the region exhibiting high sequence similarity between CYP11B1 and CYP11B2, and 53.3% of the cases were identified as having a gene conversion in intron 2. More importantly, there were six cases for whom the PCR products indicated a chimeric gene, but the GRAde results revealed no crossover pattern. The crossover regions were further verified by Sanger sequencing analysis.ConclusionsPCR-based target enrichment followed by long-read sequencing is an efficient and precise approach to dissecting complex genomic regions, such as those involved in GRA mutations, which could be directly applied to clinical diagnosis. The scripts of GRAde are available at https://github.com/hsu-binfo/GRAde.

Deksametazon Süpresyon Testlerinin Hiperkortizolizm Ayırıcı Tanısında Kullanımı

Dexamethasone suppression tests (DST) are practical, cheap and safe tests which are used to evaluate endogenous hypercortisolism. They are based on the principle that glucocorticoids exogenously given at supraphysiological doses suppress the production of CRH, ACTH and cortisol by binding to central glucocorticoid receptors. Lack of suppression of cortisol production suggest endogenous hypercortisolism. Additionally, DST may be used in the diagnosis of glucocorticoid remediable hyperaldosteronism. Due to strong glucocorticoid activity, lack of mineralocorticoid activity and lack of cross-reaction with the measurement of cortisol, dexamethasone is the preferred drug for the tests. As a screening tool in endogenous hypercortisolism, overnight 1 mg DST is used. If screening test is negative, hypercortisolism is excluded; but if the test is positive, 2-day 2 mg DST should be performed to confirm the diagnosis of Cushing’s syndrome. If endogenous hypercortisolism is confirmed, plasma ACTH should be measured. Undetectable plasma ACTH level suggest ACTH-independent Cushing’s syndrome, but inappropriately normal or high plasma ACTH level suggest ACTH-dependent Cushing’s syndrome. High dose DST (overnight 8 mg or 2-day 8 mg) should be performed to discriminate pituitary or extra-pituitary cause in the patients with ACTH-dependent Cushing’s syndrome. In the presence of pituitary Cushing’s disease, because of relatively preserved negative feedback mechanism, high dose dexamethasone may suppress ACTH. In ectopic ACTH secretion, due to lack of a normal negative feedback mechanism, ACTH cannot be suppressed by high dose dexamethasone. Extraordinarily, ectopic ACTH production in some neuroendocrine tumors may be suppressed by high dose dexamethasone, but no suppression may be observed in some patients with pituitary Cushing’s disease. When applying DST, serum and plasma samples should be collected in appropriate route, and they should be transferred by true collection tubes and in right storage conditions.

Clinical and Molecular Perspectives of Monogenic Hypertension.

Advances in molecular research techniques have enabled a new frontier in discerning the mechanisms responsible for monogenic diseases. In this review, we discuss the current research on the molecular pathways governing blood pressure disorders with a Mendelian inheritance pattern, each presenting with a unique pathophysiology. Glucocorticoid Remediable Aldosteronism (GRA) and Apparent Mineralocorticoid Excess (AME) are caused by mutations in regulatory enzymes that induce increased production of mineralocorticoids or inhibit degradation of glucocorticoids, respectively. Geller syndrome is due to a point mutation in the hormone responsive element of the promotor for the mineralocorticoid receptor, rendering the receptor susceptible to activation by progesterone, leading to hypertension during pregnancy. Pseudohypoaldosteronism type II (PHA-II), also known as Gordon’s syndrome or familial hyperkalemic hypertension, is a more variable disorder typically characterized by hypertension, high plasma potassium and metabolic acidosis. Mutations in a variety of intracellular enzymes that lead to enhanced sodium reabsorption have been identified. In contrast, hypertension in Liddle’s syndrome, which results from mutations in the Epithelial sodium Channel (ENaC), is associated with low plasma potassium and metabolic alkalosis. In Liddle’s syndrome, truncation of one the ENaC protein subunits removes a binding site necessary protein for ubiquitination and degradation, thereby promoting accumulation along the apical membrane and enhanced sodium reabsorption. The myriad effects due to mutation in phosphodiesterase 3A (PDE3A) lead to severe hypertension underlying sodium-independent autosomal dominant hypertension with brachydactyly. How mutations in PDE3A result in the phenotypic features of this disorder are discussed. Understanding the pathologies of these monogenic hypertensive disorders may provide insight into the causes of the more prevalent essential hypertension and new avenues to unravel the complexities of blood pressure regulation.

SUN-191 The Creatinine, the Crib and the Manometer - Navigating the Labyrinth of Primary Aldosteronism

A 21-year-old Ethiopian female with a five-year history of hypertension presented to medicine clinic with headaches and fatigue for two weeks. She was hypertensive to 163/113 mmHg. She had recently moved to the US and no prior medical records were available. She had been taking an unknown antihypertensive until three weeks prior. She was found to have a creatinine of 3.49 mg/dL. Renal ultrasound revealed bilateral, small echogenic kidneys without any evidence of renal artery stenosis. An intrauterine pregnancy was also incidentally discovered. Her aldosterone level was elevated to 486 ng/dL and her renin activity was 1.3 ng/ml/hr, with a ratio of 373, diagnostic of primary aldosteronism. Due to the markedly high ratio, a saline suppression test was deemed unnecessary for confirmation. Her serum potassium was normal at 3.6 mEq, likely due to poor renal clearance. Given renal failure, a CT non-contrast of the adrenal glands was performed with normal findings. She elected to terminate the high-risk pregnancy.Based upon her young age at presentation, family history of early onset hypertension, grossly elevated aldosterone: renin ratio and unrevealing workup for a primary tumor or hyperplastic adrenals, a diagnosis of familial hyperaldosteronism was considered. She failed a month-long trial of dexamethasone therapy, therefore glucocorticoid remediable aldosteronism was excluded. She was subsequently started on spironolactone with good response. Adrenal vein sampling was considered to find a surgical target for adrenalectomy but could not be performed given worsening kidney function. After discussion with Nephrology she opted for a pre-emptive renal transplant evaluation, rather than pursuing dialysis. Genetic testing for subclassification has been negative for mutations in KCNJ5 and CACNA1H with ongoing testing for novel mutations.Primary aldosteronism (PA) usually presents with recalcitrant hypertension, hypokalemia and an elevated aldosterone: renin ratio. It is commonly attributed to adrenal adenomas or hyperplasia with familial hyperaldosteronism (FH) remaining a rare etiology. FH is sub-divided into glucocorticoid remediable, type I, and non- glucocorticoid remediable, types II – IV. The initial diagnosis of such a condition during pregnancy and in the setting of worsening kidney disease presents a diagnostic and management challenge as this precludes adrenal vein sampling and contrast imaging. Our case highlights the importance of early screening for PA and illustrates the need for updated guidelines on aldosteronism workup in the setting of ESRD and pregnancy.

Maintenance of long-term blood pressure control and vascular health by low-dose amiloride-based therapy in hyperaldosteronism.

Whether aldosterone itself contributes directly to macro- or microcirculatory disease in man or to adverse cardiovascular outcomes is not fully known. We report our long-term single-practice experience in an unusual group of five patients with chronic hyperaldosteronism (HA, including three with glucocorticoid-remediable aldosteronism, GRA) treated with low-dose amiloride (a specific epithelial sodium channel [ENaC] blocker) 5-10 (mean 7) mg daily for 14-28 (mean 20) years. Except for one GRA diagnosed in infancy, all had severe resistant hypertension. In each case, BP was normalized within 1-4weeks after starting amiloride and office BP's remained well controlled throughout the next two decades. 24-hour ambulatory BP monitoring with pulse wave analysis (cardiac output, vascular resistance, augmentation index, reflection magnitude), regional pulse wave velocities, pulse stiffening ratio, ankle-brachial index, serum creatinine, estimated glomerular filtration rate, and spot urinary albumin:creatinine ratio were measured after a mean of 18years; all of these indicators were essentially normal. Over two additional years of observation (100 patient-years total), no cardiovascular or renal event occurred. We conclude that long-term ENaC blockade with amiloride can normalize BP and protect macro- and microvascular function in patients with HA. This suggests that either (a) putative vasculopathic effects of aldosterone are mediated via ENaC or (b) aldosterone may not play a direct role in age-dependent vasculopathic changes in humans independent of blood pressure. These findings, coupled with our literature review in both animal and human results, underscore the need for additional studies.

Long-term BP control and vascular health in patients with hyperaldosteronism treated with low-dose, amiloride-based therapy.

Whether aldosterone itself contributes directly to macro- or microcirculatory disease in man or to adverse cardiovascular outcomes is not fully known. We report our long-term single-practice experience in 5 patients with chronic hyperaldosteronism (HA, including 3 with glucocorticoid remediable aldosteronism, GRA) treated with low-dose amiloride (a specific epithelial sodium channel [ENaC] blocker) 5-10 (mean 7) mg daily for 14-28 (mean 20) years. Except for 1 GRA diagnosed in infancy, all had severe resistant hypertension. In each case, BP was normal or near-normal within 1-4weeks after starting amiloride and office BP's were well controlled for 20years thereafter. Vascular studies and 24-hour ambulatory BP monitoring with pulse wave analysis (cardiac output, vascular resistance, augmentation index, and reflection magnitude) were assessed after a mean of 18years as were regional pulse wave velocities, pulse stiffening ratio, ankle-brachial index, serum creatinine, estimated glomerular filtration rate, and spot urinary albumin:creatinine ratio. All indicators were completely normal in all patients after 18years of amiloride, and none had a cardiovascular event during the 20-year mean follow-up. We conclude that long-term ENaC blockade can normalize BP and protect macro- and microvascular function in patients with HA. This suggests that (a) any vasculopathic effects of aldosterone are mediated via ENaC, not MR activation itself, and are fully preventable or reversible with ENaC blockade or (b) aldosterone may not play a major BP-independent role in human macro- and microcirculatory diseases. These and other widely divergent results in the literature underscore the need for additional studies regarding aldosterone, ENaC, and vascular disease.

Timeline of Advances in Genetics of Primary Aldosteronism.

The overwhelming majority of cases of primary aldosteronism (PA) occur sporadically due to a unilateral aldosterone-producing adenoma (APA) or bilateral idiopathic adrenal hyperplasia. Familial forms of PA are rare with four subtypes defined to date (familial hyperaldosteronism types I-IV). The molecular basis of familial hyperaldosteronism type I (FH type I or glucocorticoid-remediable aldosteronism) was established in 1992; two decades later the genetic variant causing FH type III was identified and germline mutations causing FH type IV and FH type II were determined soon after. Effective diagnostic protocols and methods to detect the overactive gland in unilateral PA by adrenal venous sampling followed by laparoscopic adrenalectomy have made available APAs for scientific studies. In rapid succession, following the widespread use of next-generation sequencing, recurrent somatic driver mutations in APAs were identified in genes encoding ion channels and transporters. The development of highly specific monoclonal antibodies against key enzymes in adrenal steroidogenesis has unveiled the heterogeneous features of the diseased adrenal in PA and helped reveal the high proportion of APAs with driver mutations. We discuss what is known about the genetics of PA that has led to a clearer understanding of the disease pathophysiology.

DIAGNOSIS OF ENDOCRINE DISEASE: 18-Oxocortisol and 18-hydroxycortisol: is there clinical utility of these steroids?

Since the early 1980s 18-hydroxycortisol and 18-oxocortisol have attracted attention when it was shown that the urinary excretion of these hybrid steroids was increased in primary aldosteronism. The development and more widespread use of specific assays has improved the understanding of their role in the (patho)physiology of adrenal disorders. The adrenal site of synthesis is not fully understood although it is clear that for the synthesis of 18-hydroxycortisol and 18-oxocortisol the action of both aldosterone synthase (zona glomerulosa) and 17α-hydroxylase (zona fasciculata) is required with cortisol as main substrate. The major physiological regulator is ACTH and the biological activity of both steroids is very low and therefore only very high concentrations might be effective in vivo In healthy subjects, the secretion of both steroids is low with 18-hydroxycortisol being substantially higher than that of 18-oxocortisol. The highest secretion of both steroids has been found in familial hyperaldosteronism type 1 (glucocorticoid-remediable aldosteronism) and in familial hyperaldosteronism type 3. Lower but yet substantially increased secretion is found in patients with aldosterone-producing adenomas in contrast to bilateral hyperplasia in whom the levels are similar to patients with hypertension. Several studies have attempted to show that these steroids, in particular, peripheral venous plasma 18-oxocortisol, might be a useful discriminatory biomarker for subtyping PA patients. The current available limited evidence precludes the use of these steroids for subtyping. We review the biosynthesis, regulation and function of 18-hydroxycortisol and 18-oxocortisol and their potential utility for the diagnosis and differential diagnosis of patients with primary aldosteronism.

Genomics and Precision Medicine for Clinicians and Scientists in Hypertension.

In 1903, Sir William Osler wrote “the good physician treats the disease; the great physician treats the patient who has the disease.” These words ring very true in 2016 as we approach the era of precision or stratified medicine. The precision or stratified medicine (we are going to use these terms interchangeably) is based on identifying subgroups of patients with distinct mechanisms of disease and particular responses to treatments. This allows us to identify and develop treatments that are effective for particular groups of patients. Ultimately, precision medicine will ensure that the right patient gets the right treatment at the right time. The above definition broadly follows suggested definition published by the UK Medical Research Council (http://www.mrc.ac.uk/research/initiatives/stratified-medicine/). We can therefore summarize the promise of precision medicine as being able to remove nonresponders and toxic responders before prescribing medication and to treat with a given drug only responders and patients not predisposed to toxicity. Such approaches are very well developed in cancer medicine with several examples of successful precision medicine applications in breast, prostate, ovarian, colon, and pancreatic cancer,1–6 and this list is by no means complete. Cardiovascular medicine in general and hypertension in particular both lag behind oncology in this respect. However, there are examples from rare monogenic syndromes, where a single genetic mutation explains the entire pathophysiology of severe, early onset hypertension and dictating perfect pharmacogenetics-led prescription.7,8 These syndromes include the Glucocorticoid Remediable Aldosteronism, Liddle Syndrome, and pseudohypoaldosteronism type II to name just a few. In these syndromes, glucocorticoids, amiloride, and thiazide diuretics, …

Pathogenetic forms of primary hyperaldosteronism: the analysis of clinical series of patients

Frequency of different clinical variants of primary hyperaldosteronism (PHA) has a particular interest for modern endocrinology because paradigm in understanding the pathogenesis of disease were changed.Purpose. The aim of the study was to establish the frequency of different clinical variants of PHA on the cohort of patients treated in Ukrainian Scientific and Practical Center of Endocrine Surgery within period of 1996–2014 years.Materials and methods. Results of diagnosis and treatment of 474 patients, who underwent surgical and therapeutic procedures, were retrospectively studied. All patients were investigated by screening of serum potassium, aldosteron-renin ratio, confirmation tests, multi-spiral computed tomography. Selective adrenal vein sampling was performed in 63 cases.Results and discussion. Analysis of PHA structure demonstrated the following distribution of forms: idiopathic adrenal hyperplasia – 235 (49.6%), aldosteron-producing adenoma – 195 (41.1%), primary (unilateral) adrenal hyperplasia – 36 (7.6%), familial forms of PHA – 6 (1.3%) (incl. GRA – 4, FH II – 2), adrenocortical carcinoma – 2 (0.4%). 255 patients were operated by unilateral laparoscopic adrenalectomy. Among 219 patients from the group of conservative treatment of PHA glucocorticoid-remediable aldosteronism (GRA) was suspected in у 22 patients and have been confirmed by ex-uvantibus treatment with dexamethasone in 4 patients. The rest of patients received treatment by antagonists of mineralocorticoid receptors.Conclusions. The first in Ukraine analysis of modern distribution clinical variants of PHA has demonstrated variability of disease with predomination of idiopathic bilateral adrenal hyperplasia and gradually decreasing the share of aldosteron- producing adenoma. Accurate diagnosis of specific form of primary hyperaldosteronism allows choosing adequate mode of therapy.

PP.25.11] GLUCOCORTICOID-REMEDIABLE ALDOSTERONISM (GRA)

Objective: Glucocorticoid-remediable aldosteronism (GRA) is a rare cause of hypertension and hypokalaemia mediated by hyperaldosteronism. An association with cerebral aneurysms has also been described. GRA is due to a mutation of the GRA gene and it is transmitted as autosomal dominant trait. Cascade genetic screening of first-degree relatives of an index case is a strategy to identify individuals affected. However, the penetrance and expressivity of the GRA gene are not known. Our aim was to describe a case highlighting a profound discrepancy between genotype and phenotype. Design and method: Case report with description of family pedigree, molecular genetic tests for GRA, clinical and biochemical phenotype. Results: A 33-year old woman was referred to our unit for the assessment of possible GRA and related-cerebral aneurysms. Pedigree: mother and one of her 3 siblings had a diagnosis of GRA supported by positive genetic tests. Both affected relatives had been prescribed corticosteroid therapy and had cerebral aneurysms coiled. In our patient PCR analysis was positive for the 3.9 fragment indicating the chimeric gene characteristic of GRA. However, she was consistently normotensive in the clinic and had a mean blood pressure of 135/85 on 24-hour monitoring. Blood tests showed normal serum potassium at 3.9 mmol/L and normal aldosterone/renin ratio after prolonged sitting at 767 (pmol/L over pmol/mL/hour). Magnetic resonance imaging did not identify cerebral aneurysms. Conclusions: Our case demonstrates that the expressivity and penetrance of the GRA gene can be variable and that the presence of GRA gene mutation does not necessarily predict the clinical phenotype of hyperaldosteronism. This finding has crucial implications in terms of strategy for cascade family screening as well as for the implications of a positive genetic test for the individuals tested.

Role of ACTH and Other Hormones in the Regulation of Aldosterone Production in Primary Aldosteronism

The major physiological regulators of aldosterone production from the adrenal zona glomerulosa are potassium and angiotensin II; other acute regulators include adrenocorticotropic hormone (ACTH) and serotonin. Their interactions with G-protein coupled hormone receptors activate cAMP/PKA pathway thereby regulating intracellular calcium flux and CYP11B2 transcription, which is the specific steroidogenic enzyme of aldosterone synthesis. In primary aldosteronism (PA), the increased production of aldosterone and resultant relative hypervolemia inhibits the renin and angiotensin system; aldosterone secretion is mostly independent from the suppressed renin–angiotensin system, but is not autonomous, as it is regulated by a diversity of other ligands of various eutopic or ectopic receptors, in addition to activation of calcium flux resulting from mutations of various ion channels. Among the abnormalities in various hormone receptors, an overexpression of the melanocortin type 2 receptor (MC2R) could be responsible for aldosterone hypersecretion in aldosteronomas. An exaggerated increase in plasma aldosterone concentration (PAC) is found in patients with PA secondary either to unilateral aldosteronomas or bilateral adrenal hyperplasia (BAH) following acute ACTH administration compared to normal individuals. A diurnal increase in PAC in early morning and its suppression by dexamethasone confirms the increased role of endogenous ACTH as an important aldosterone secretagogue in PA. Screening using a combination of dexamethasone and fludrocortisone test reveals a higher prevalence of PA in hypertensive populations compared to the aldosterone to renin ratio. The variable level of MC2R overexpression in each aldosteronomas or in the adjacent zona glomerulosa hyperplasia may explain the inconsistent results of adrenal vein sampling between basal levels and post ACTH administration in the determination of source of aldosterone excess. In the rare cases of glucocorticoid remediable aldosteronism, a chimeric CYP11B2 becomes regulated by ACTH activating its chimeric CYP11B1 promoter of aldosterone synthase in bilateral adrenal fasciculate-like hyperplasia. This review will focus on the role of ACTH on excess aldosterone secretion in PA with particular focus on the aberrant expression of MC2R in comparison with other aberrant ligands and their GPCRs in this frequent pathology.

SFE/SFHTA/AFCE consensus on primary aldosteronism, part 5: Genetic diagnosis of primary aldosteronism

While the majority of cases of primary aldosteronism (PA) are sporadic, four forms of autosomal-dominant inheritance have been described: familial hyperaldosteronism (FH) types I to IV. FH-I, also called glucocorticoid-remediable aldosteronism, is characterized by early and severe hypertension, usually before the age of 20 years. It is due to the formation of a chimeric gene between the adjacent CYP11B2 and CYP11B1 genes (coding for aldosterone synthase and 11β-hydroxylase, respectively). FH-I is often associated with family history of stroke before 40years of age. FH-II is clinically and biochemically indistinguishable from sporadic forms of PA and is only diagnosed on the basis of two or more affected family members. No causal genes have been identified so far and no genetic test is available. FH-III is characterized by severe and early-onset hypertension in children and young adults, resistant to treatment and associated with severe hypokalemia. Mild forms, resembling FH-II, have been described. FH-III is due to gain-of-function mutations in the KCNJ5 gene. Recently, a new autosomal-dominant form of familial PA, FH-IV, associated with mutations in the CACNA1H gene, was described in patients with hypertension and PA before the age of 10years. In rare cases, PA may be associated with complex neurologic disorder involving epileptic seizures and cerebral palsy (Primary Aldosteronism, Seizures, and Neurologic Abnormalities [PASNA]) due to de novo germline CACNA1D mutations.