In vivo formation of adrenal organoids in a novel porcine model of adrenocortical cell transplantation.

Recognising the limitations of current therapies for Addison's disease, novel treatments that replicate dynamic physiologic corticosteroid secretion, under control of adrenocorticotropic hormone, are required. The aim of these experiments was to evaluate the feasibility of adrenocortical cell transplantation (ACT) in a large animal model, adapting methods successfully used for intra-cutaneous pancreatic islet cell transplantation, using a fully biodegradable temporising matrix. Autologous porcine ACT was undertaken by bilateral adrenalectomy, cell isolation, culture and intracutaneous injection into a skin site pre-prepared using a biodegradable temporising matrix (BTM) foam. Hydrocortisone support was provided during adrenocortical cell engraftment and weaned as tolerated. Blood adrenocortical hormone concentrations were monitored and the transplant site was examined at end-point. Outcome measures included cellular histochemistry, systemic hormone production and hydrocortisone independence. Transplanted adrenocortical cells showed a capability to survive and proliferate within the intracutaneous site, and an ability to self-organise into discrete tissue organoids with features of the normal adrenal histologic architecture. Interpretation of systemic hormone levels was confounded by identification of accessory adrenals and regenerative cortical tissue within the adrenal bed post-mortem. Corticosteroids were unable to be completely ceased. ACT in a large animal model has not previously been attempted, yet it is an important step towards clinical translation. These results demonstrate potential for ACT based on the development of adrenal organoids at the BTM site. However, the inability to achieve clinically relevant systemic hormone production suggests insufficient function, likely attributable to insufficient cells through delivered dose and subsequent proliferation.

Triiodothyronine supplementation in a sheep model of intensive care.

Triiodothyronine (T3) concentrations in plasma decrease during acute illness and it is unclear if this contributes to disease. Clinical and laboratory studies of T3 supplementation in disease have revealed little or no effect. It is uncertain if short term supplementation of T3 has any discernible effect in a healthy animals. Observational study of intravenous T3 (1 µg/kg/h) for 24 h in a healthy sheep model receiving protocol-guided intensive care supports (T3 group, n=5). A total of 45 endpoints were measured including hemodynamic, respiratory, renal, hematological, metabolic and endocrine parameters. Data were compared with previously published studies of sheep subject to the same support protocol without administered T3 (No T3 group, n=5). Plasma free T3 concentrations were elevated 8-fold by the infusion (pmol/l at 24 h; T3 group 34.9±9.9 vs. No T3 group 4.4±0.3, P<0.01, reference range 1.6 to 6.8). There was no significant physiological response to administration of T3 over the study duration. Supplementation of intravenous T3 for 24 h has no physiological effect on relevant physiological endpoints in healthy sheep. Further research is required to understand if the lack of effect of short-term T3 may be related to kinetics of T3 cellular uptake, metabolism and action, or acute counterbalancing hormone resistance. This information may be helpful in design of clinical T3 supplementation trials.

Cortisol, Stress, and Disease-Bidirectional Associations; Role for Corticosteroid-Binding Globulin?

Selye described stress as a unified neurohormonal mechanism maintaining homeostasis. Acute stress system activation is adaptive through neurocognitive, catecholaminergic, and immunomodulation mechanisms, followed by a reset via cortisol. Stress system components, the sympathoadrenomedullary system, hypothalamic-pituitary-adrenal axis, and limbic structures are implicated in many chronic diseases by establishing an altered homeostatic state, allostasis. Consequent "primary stress system disorders" were popularly accepted, with phenotypes based on conditions such as Cushing syndrome, pheochromocytoma, and adrenal insufficiency. Cardiometabolic and major depressive disorders are candidates for hypercortisolemic etiology, contrasting the "hypocortisolemic symptom triad" of stress sensitivity, chronic fatigue, and pain. However, acceptance of chronic stress etiology requires cause-and-effect associations, and practical utility such as therapeutics altering stress system function. Inherent predispositions to stress system perturbations may be relevant. Glucocorticoid receptor (GR) variants have been associated with metabolic/neuropsychological states. The SERPINA6 gene encoding corticosteroid-binding globulin (CBG), was the sole genetic factor in a single-nucleotide variation-genome-wide association study linkage study of morning plasma cortisol, a risk factor for cardiovascular disease, with alterations in tissue-specific GR-related gene expression. Studies showed genetically predicted high cortisol concentrations are associated with hypertension and anxiety, and low CBG concentrations/binding affinity, with the hypocortisolemic triad. Acquired CBG deficiency in septic shock results in 3-fold higher mortality when hydrocortisone administration produces equivocal results, consistent with CBG's role in spatiotemporal cortisol delivery. We propose some stress system disorders result from constitutional stress system variants rather than stressors themselves. Altered CBG:cortisol buffering may influence interstitial cortisol ultradian surges leading to pathological tissue effects, an example of stress system variants contributing to stress-related disorders.

Increased prevalence of germline pathogenic CHEK2 variants in individuals with pituitary adenomas.

CONTEXT: CHEK2 is a cell cycle checkpoint regulator gene with a long-established role as a clinically relevant, moderate risk breast cancer predisposition gene, with greater risk ascribed to truncating variants than missense variants. METHODS: We assessed 165 individuals with pituitary adenomas for CHEK2 variants. The study consisted of a primary cohort of 29 individuals who underwent germline and tumour whole exome sequencing, and a second, independent cohort of 136 individuals who had a targeted next-generation sequencing panel performed on both germline and tumour DNA (n=52) or germline DNA alone (n=84). RESULTS: We identified rare, coding, non-synonymous germline CHEK2 variants amongst 3/29 (10.3%) patients in our primary cohort and 5/165 (3.0%) patients overall, with affected patients having a range of hormone secretion types (prolactinoma, thyrotrophinoma, somatotrophinoma and non-functioning pituitary adenoma). No somatic variants were identified. Two variants were definitive null variants (c.1100delC, c.444+1G>A), classified as pathogenic. Two variants were missense variants (p.Asn186His, p.Thr476Met), classified as likely pathogenic. Even when considering the null variants only, the rate of CHEK2 variants was higher in our cohort compared to national control data (1.8% vs. 0.5%, P=0.049). CONCLUSIONS: This is the first study to suggest a role for the breast cancer predisposition gene, CHEK2, in pituitary tumorigenesis, with pathogenic/likely pathogenic variants found in 3% of patients with pituitary adenomas. As pituitary adenomas are relatively common and typically lack classical autosomal dominant family histories, risk alleles - such as these variants found in CHEK2 - might be a significant contributor to pituitary adenoma risk in the general population.

Is high salt intake inducing obesity via production of cortisol? A novel working hypothesis and pilot study.

PURPOSE: Evidence is growing that high salt intake is an independent risk factor for obesity, but the mechanisms are unknown. Our novel working hypothesis is that high salt intake drives cortisol production, which in turn, drives obesity. The current study aimed to demonstrate an acute cortisol response following a single high salt meal. METHODS: Eight participants (age 30.5 ± 9.8 years [mean ± SD], 50% female), consumed high salt (3.82 g; 1529 mg sodium) and low salt (0.02 g; 9 mg sodium) meals in a randomized cross-over design. RESULTS: Urinary and salivary cortisol and plasma adrenocorticotropic hormone (ACTH) demonstrated order effects. When high salt was given second, there was a peak above baseline for urinary cortisol (26.3%), salivary cortisol (9.4%) and plasma ACTH (4.1%) followed by a significant decline in each hormone (treatment*time, F[9, 18] = 2.641, p = 0.038, partial η2 = 0.569; treatment*time, F[12, 24] = 2.668, p = 0.020, partial η2 = 0.572; treatment*time, F[12, 24] = 2.580, p = 0.023, partial η2 = 0.563, respectively), but not when high salt was given first (p > 0.05 for all). CONCLUSION: These intriguing findings provide partial support for our hypothesis and support a need for further research to elucidate the role of high salt intake in cortisol production and, in turn, in the aetiology of obesity. TRIAL REGISTRATION NUMBER: ACTRN12623000490673; date of registration 12/05/2023; retrospectively registered.

Novel agents to treat adrenal insufficiency: findings of preclinical and early clinical trials.

INTRODUCTION: Adrenal insufficiency currently affects over 300/million population, with higher morbidity and mortality compared to the general population. Current glucocorticoid replacement therapy is limited by a lack of reliable biomarkers to guide dosing, inter-patient variation in metabolism and narrow therapeutic window. Increased morbidity and mortality may relate to unappreciated under- or over-exposure to glucocorticoids and impaired cortisol circadian rhythm. New agents are required to emulate physiological cortisol secretion and individualize glucocorticoid dosing. AREAS COVERED: History of glucocorticoid therapy, current limitations, and novel chronotherapeutic glucocorticoid delivery mechanisms. Literature search incorporated searches of PubMed and Embase utilizing terms such as adrenal insufficiency, Chronocort, Plenadren, continuous subcutaneous hydrocortisone infusion (CHSI), and glucocorticoid receptor modulator. EXPERT OPINION: Glucocorticoid chronotherapy is necessary to optimize glucocorticoid exposure and minimize complications. Current oral chronotherapeutics provide improved dosing functionality, but are modifiable only in specific increments and cannot accommodate ultradian cortisol variation. Current data show improvement in quality of life but not morbidity or mortality outcomes. CHSI has significant potential for individualized glucocorticoid dosing, but would require a suitable biomarker of glucocorticoid adequacy to be implementable. Avenues for future research include determining a glucocorticoid sufficiency biomarker, development of interstitial or systemic cortisol monitoring, or development of glucocorticoid receptor modulators.

Approach to the Patient: Reninoma.

A reninoma is a functional tumor of afferent arteriolar juxtaglomerular cells that secretes the enzyme renin, leading to hyperactivation of the renin-angiotensin-aldosterone system. Reninoma is a potentially curable cause of pathological secondary hyperaldosteronism that results in often severe hypertension and hypokalemia. The lack of suppression of plasma renin contrasts sharply with the much more common primary aldosteronism, but diagnosis is often prompted by screening for that condition. The major differential diagnosis of reninoma is renovascular hypertension. Fewer than 200 cases of reninoma have been described. Reninomas have been reported across a broad demographic but have a 2:1 predilection for women, often of childbearing age. Aldosterone receptor blockade, angiotensin-converting enzyme inhibitors, or angiotensin receptor blockers offer effective medical management but are contraindicated in pregnancy, so surgical curative resection is ideal. The current optimal imaging and biochemical workup of reninoma and management approach (ideally, tumor excision with subtotal renal resection) are described.

Identification of monogenic diabetes in an Australian cohort using the Exeter maturity-onset diabetes of the young (MODY) probability calculator and next-generation sequencing gene panel testing.

AIMS: This study aims to describe the prevalence of monogenic diabetes in an Australian referral cohort, in relation to Exeter maturity-onset diabetes of the young (MODY) probability calculator (EMPC) scores and next-generation sequencing with updated testing where relevant. METHODS: State-wide 5-year retrospective cohort study of individuals referred for monogenic diabetes genetic testing. RESULTS: After excluding individuals who had cascade testing for a familial variant (21) or declined research involvement (1), the final cohort comprised 40 probands. Incorporating updated testing, the final genetic result was positive (likely pathogenic/pathogenic variant) in 11/40 (27.5%), uncertain (variant of uncertain significance) in 8/40 (20%) and negative in 21/40 (52.5%) participants. Causative variants were found in GCK, HNF1A, MT-TL1 and HNF4A. Variants of uncertain significance included a novel multi-exonic GCK duplication. Amongst participants with EMPC scores ≥ 25%, a causative variant was identified in 37%. Cascade testing was positive in 9/10 tested relatives with diabetes and 0/6 tested relatives with no history of diabetes. CONCLUSIONS: Contemporary genetic testing produces a high yield of positive results in individuals with clinically suspected monogenic diabetes and their relatives with diabetes, highlighting the value of genetic testing for this condition. An EMPC score cutoff of ≥ 25% correctly yielded a positive predictive value of ≥ 25% in this multiethnic demographic. This is the first Australian study to describe EMPC scores in the Australian clinic setting, albeit a biased referral cohort. Larger studies may help characterise EMPC performance between ethnic subsets, noting differences in the expected probability of monogenic diabetes relative to type 2 diabetes.

The Learning Curve for Endoscopic Endonasal Transsphenoidal Pituitary Surgery: Evaluating Endocrine Outcomes.

OBJECTIVE: In South Australia endoscopic endonasal approach (EEA) pituitary surgery has been practiced since 2006, largely by two neurosurgeons with a small fellowship-trained otolaryngology team. The aim of this cohort study was to determine if a "learning curve" can be established over this time period, as represented by structural and endocrine patient outcomes. METHOD: Retrospective cohort study of patients undergoing EEA surgery between 2006 and 2021 in Adelaide, South Australia at three tertiary teaching hospitals.. Cases were divided by each surgeon and split into groups of sequential 40 cases. Endocrine assessment pre- and post-operatively involved static pituitary and end-organ hormones, with dynamic tests as required, assessed by an pituitary endocrinologist. Each hormonal axis (gonadal, cortisol, thyroid, prolactin and growth hormone) was documented preoperatively and at an early and long term follow up at 1-2 and 12 months, respectively. RESULTS: The study included a cohort of 443 pituitary adenomas managed with endoscopic endonasal transsphenoidal surgery in a consecutive fashion between two neurosurgeons over 16-years. Gross tumour resection but not visual visual outcomes improved with surgical experience but this outcome may be neurosurgeon dependent. Endocrine outcomes were not consistently improved with experience, but lower rates of hypopituitarism were seen with experience with one neurosurgeon. Average follow up was approximately 5 years, and a minimum follow up of 12 months for all patients. CONCLUSIONS: We present long term endocrine follow up for patients with functional and non-functional adenomas. Improved rates of gross tumour resection were evident with with surgical experience. However, there was no apparent change in post-operative endocrine outcomes.

A clinical perspective on ectopic Cushing's syndrome.

Cushing's syndrome (CS) refers to the clinical features of prolonged pathological glucocorticoid excess. About 10-20% of individuals with CS have ectopic CS (ECS), that is, an adrenocorticotropin (ACTH)-producing tumour outside the pituitary gland. ACTH-secreting neuroendocrine neoplasia (NENs) can arise from many organs, although bronchial NEN, small cell lung cancer (SCLC), pancreatic NEN, thymic NEN, medullary thyroid cancer (MTC), and pheochromocytoma are the most common. Patients with ECS frequently present with severe hypercortisolism. The risk of life-threatening complications is high in severe cases, unless the hypercortisolism is effectively treated. A good outcome in ECS requires a methodical approach, incorporating prompt diagnosis, tumour localization, control of cortisol excess, and resection of the primary tumour when possible.

PAM variants in patients with thyrotrophinomas, cyclical Cushing's disease and prolactinomas.

Introduction: Germline loss-of-function variants in PAM, encoding peptidylglycine α-amidating monooxygenase (PAM), were recently discovered to be enriched in conditions of pathological pituitary hypersecretion, specifically: somatotrophinoma, corticotrophinoma, and prolactinoma. PAM is the sole enzyme responsible for C-terminal amidation of peptides, and plays a role in the biosynthesis and regulation of multiple hormones, including proopiomelanocortin (POMC). Methods: We performed exome sequencing of germline and tumour DNA from 29 individuals with functioning pituitary adenomas (12 prolactinomas, 10 thyrotrophinomas, 7 cyclical Cushing's disease). An unfiltered analysis was undertaken of all PAM variants with population prevalence <5%. Results: We identified five coding, non-synonymous PAM variants of interest amongst seven individuals (six germline, one somatic). The five variants comprised four missense variants and one truncating variant, all heterozygous. Each variant had some evidence of pathogenicity based on population prevalence, conservation scores, in silico predictions and/or prior functional studies. The yield of predicted deleterious PAM variants was thus 7/29 (24%). The variants predominated in individuals with thyrotrophinomas (4/10, 40%) and cyclical Cushing's disease (2/7, 29%), compared to prolactinomas (1/12, 8%). Conclusion: This is the second study to demonstrate a high yield of suspected loss-of-function, predominantly germline, PAM variants in individuals with pathological pituitary hypersecretion. We have extended the association with corticotrophinoma to include the specific clinical entity of cyclical Cushing's disease and demonstrated a novel association between PAM variants and thyrotrophinoma. PAM variants might act as risk alleles for pituitary adenoma formation, with a possible genotype-phenotype relationship between truncating variants and altered temporal secretion of cortisol.

Factors underlying a disproportionate increase in hospital admissions for adrenal insufficiency in women aged 20-29 years.

Since the year 2000, admissions for adrenal insufficiency (AI) and adrenal crises (AC) have shown a particular increase in young adult females. We examined data on acute non-surgical hospitalisations for AI/AC from New South Wales, Australia, to determine relevant factors that may have contributed to this increase. Data were analysed to ascertain associations between various comorbid psychosocial issues, identified by relevant ICD-10-AM codes in each record, and ACs. From 2005 to 2021. There were 877 admissions for an acute non-surgical illness in this age group. The average admission rate for females [63.5/million/year] was almost twice that for males [34.0/million/year] (p<0.01), as was the average female AC admission rate [14.7/million/year] relative to that in males [6.75/million/year] (p=NS). Infection was present in 41.6% (n=365) of the admissions and Type 1 diabetes mellitus was present in 12.2% (n=107). Overall, psychosocial factors were considered by the senior clinician to have contributed to the illness episode in 22.1% of all admissions and 29.0% of AC admissions. Having one or more psychosocial problems was associated with an AC in females (37.4%, n=49, in those having an AC, p<0.001) but not males. Females with an AC also had a higher mean composite psychosocial, psychiatric and drug/alcohol score [0.47 (0.67)] than females without an AC [0.32 (0.62) p<0.05]. No comparable associations were found in male patients. An increase in the rates of hospitalisations that included a code for at least one psychosocial problem was highly correlated with increases in admission rates for both ACs (r=0.82, p<0.001) and all AI (r=0.98, p<0.001) in females but there was no such relationship in males. This new evidence suggests that psychosocial factors may play an important role in ongoing rates of ACs in treated AI (incidence approximately 6-8 ACs/100PY) particularly in young adult females. In order to minimize AC episodes, all barriers to self-management need exploration on an individual patient basis and with regard to the patient population as a whole.

Cabergoline-associated valvulopathy of the tricuspid valve in the treatment of prolactinoma.

Cabergoline-associated valvulopathy (CAV) is defined by the echocardiographic triad of moderate or severe regurgitation, valvular thickening and restricted valvular motion. While it is a well-described complication of dopamine agonist therapy in Parkinson's disease, only three convincing cases of CAV have previously been described in the treatment of prolactinoma, with none involving the tricuspid valve. We describe a case of CAV affecting the tricuspid valve, ultimately resulting in the patient's death. The novel finding of CAV affecting the tricuspid valve suggests a possible link between confirmed cases of CAV and the echocardiographic surveillance studies of cabergoline-treated prolactinoma patients which have mostly demonstrated subclinical tricuspid valve changes. The risk of CAV, although small, prompts a mindful prescription of dopamine agonist therapy for prolactinomas and consideration of measures to minimise cabergoline exposure. The cumulative cabergoline doses and duration of therapy associated with CAV in published cases exceed what has been evaluated in case series and surveillance studies, underscoring the importance of case reports in understanding CAV.

Adrenal Medullary Hyperplasia: A Systematic Review and Meta-analysis.

CONTEXT: Adrenal medullary hyperplasia (AMH) is a rare, incompletely described disorder of the adrenal medulla that is associated with catecholamine excess. OBJECTIVE: To increase knowledge about AMH by reviewing the reported cases of this disorder. DESIGN: Systematic review and meta-analysis of the genotype/phenotype relationship in all reported cases of AMH. SETTING: Literature review and analysis. PATIENTS OR OTHER PARTICIPANTS: All cases of AMH published to date. MAIN OUTCOME MEASURE(S): Characteristics of AMH cases and genotype-phenotype relationships. RESULTS: A total of 66 patients, median age of 48 years, were identified from 29 reports. More than one-half were male (n = 39, 59%). The majority had unilateral (73%, n = 48) disease; 71% (n = 47) were sporadic and 23% (n = 15) were associated with the MEN2. Most (91%, n = 60) displayed signs and symptoms of excess catecholamine secretion, particularly hypertension. Elevated catecholamine concentrations (86%, n = 57) and adrenal abnormalities on imaging were common (80%, n = 53). More than one-half (58%, n = 38) had concurrent tumors: pheochromocytoma (42%, n = 16/38); medullary thyroid cancer (24%, n = 9/38); and adrenocortical adenoma (29%, n = 11/38). Most (88%, n = 58) underwent adrenalectomy with 45/58 achieving symptom resolution. Adrenalectomy was less common in patients under 40 years and those with bilateral disease (both P < .05). CONCLUSION: AMH may be sporadic or associated with MEN2, most have catecholamine excess and imaging abnormalities. Unilateral involvement is more common. Most reported patients have been treated with adrenalectomy, which is usually curative with regard to catecholamine hypersecretion.

The Changing Epidemiology of Adrenal Insufficiency: Iatrogenic Factors Predominate.

Context: Adrenal insufficiency (AI)-related morbidity persists despite efforts to minimize its effect. Reasons for this are unknown and warrant examination. Objective: This work aimed to investigate trends in AI hospitalizations and glucocorticoid (GC) replacement therapy use. Methods: Data on hospitalizations for a principal diagnosis of AI and prescriptions for short-acting GCs between 2000 and 2019 were extracted from national repositories. Age-standardized admission and prescription rates were calculated using census data. Rates were compared over time overall and according to age, sex, and disease subtype. Results: AI admissions increased by 62.0%, from 36.78/million to 59.59/million (trend P < .0001). Adrenal crisis (AC) admissions also increased, by 90.1% (from 10.73/million to 20.40/million; trend, P < .00001). These increases were more pronounced in the second decade. Prescriptions for short-acting GCs also increased (by 67.2%, from 2198.36/million in 2000/2001 to 3676.00/million in 2017/2018). Females had higher average admission rates and a greater increase in admission rates than males. Increased AI admissions were found in all age groups among females but only in men aged 70+ yrs. Secondary AI (SAI) admission rates increased by 91.7%, whereas admission rates for primary AI (PAI) remained unchanged. Conclusion: The prevalence of AI and hospitalizations for this disorder (including ACs) have increased since 2000, with a greater increase occurring after 2010. Admission rates for SAI increased but PAI admissions remained stable. Possible causes include immunotherapies for malignancy, increased cranial imaging detecting pituitary tumors and their subsequent treatment, and increased use of low-dose, short-acting GC-replacement therapy.

Future Directions for Adrenal Insufficiency: Cellular Transplantation and Genetic Therapies.

Primary adrenal insufficiency (PAI) occurs in 1 in 5 to 7000 adults. Leading etiologies are autoimmune adrenalitis in adults and congenital adrenal hyperplasia (CAH) in children. Oral replacement of cortisol is lifesaving, but poor quality of life, repeated adrenal crises, and dosing uncertainty related to lack of a validated biomarker for glucocorticoid sufficiency persists. Adrenocortical cell therapy and gene therapy may obviate many of the shortcomings of adrenal hormone replacement. Physiological cortisol secretion regulated by pituitary adrenocorticotropin could be achieved through allogeneic adrenocortical cell transplantation, production of adrenal-like steroidogenic cells from either stem cells or lineage conversion of differentiated cells, or for CAH, gene therapy to replace or repair a defective gene. The adrenal cortex is a high-turnover organ and thus failure to incorporate progenitor cells within a transplant will ultimately result in graft exhaustion. Identification of adrenocortical progenitor cells is equally important in gene therapy, for which new genetic material must be specifically integrated into the genome of progenitors to ensure a durable effect. Delivery of gene-editing machinery and a donor template, allowing targeted correction of the 21-hydroxylase gene, has the potential to achieve this. This review describes advances in adrenal cell transplants and gene therapy that may allow physiological cortisol production for children and adults with PAI.