New developments and concepts in the diagnosis and management of diabetes insipidus (AVP-deficiency and resistance).

Diabetes insipidus (DI) is a disorder characterised by the excretion of large amounts of hypotonic urine, with a prevalence of 1 per 25,000 population. Central DI (CDI), better now referred to as arginine vasopressin (AVP)-deficiency, is the most common form of DI resulting from deficiency of the hormone AVP from the pituitary. The less common nephrogenic DI (NDI) or AVP-resistance develops secondary to AVP resistance in the kidneys. The majority of causes of DI are acquired, with CDI developing when more than 80% of AVP-secreting neurons are damaged. Inherited/familial CDI causes account for approximately 1% of cases. Although the pathogenesis of NDI is unclear, more than 280 disease-causing mutations affecting the AVP2 protein or AVP V2 receptor, as well as in aquaporin 2 (AQP2), have been described. Although the cAMP/protein kinase A pathway remains the major regulatory pathway of AVP/AQP2 action, in vitro data have also revealed additional cAMP independent pathways of NDI pathogenesis. Diagnosing partial forms of DI, and distinguishing them from primary polydipsia, can be challenging, previously necessitating the use of the water deprivation test. However, measurements of circulating copeptin levels, especially after stimulation, are increasingly replacing the classical tests in clinical practice because of their ease of use and high sensitivity and specificity. The treatment of CDI relies on desmopressin administration, whereas NDI requires the management of any underlying diseases, removal of offending drugs and, in some cases, administration of diuretics. A better understanding of the pathophysiology of DI has led to novel evolving therapeutic agents that are under clinical trial.

Alterations in cortisol and interleukin-6 secretion in patients with COVID-19 suggestive of neuroendocrine-immune adaptations.

PURPOSE: The beneficial effect of glucocorticoids in coronavirus disease (COVID-19) is established, but whether adrenal cortisol secretion is impaired in COVID-19 is not fully elucidated. In this case-control study, we investigated the diurnal free bioavailable salivary cortisol secretion in COVID-19 patients. METHODS: Fifty-two consecutive COVID-19 patients-before dexamethasone treatment in cases required-recruited between April 15 to June 15, 2021, (NCT04988269) at Laikon Athens University-Hospital, and 33 healthy age- and sex-matched controls were included. Diurnal salivary cortisol (8 a.m., 12, 6, and 10 p.m.), plasma adrenocorticotropin (ACTH) and aldosterone, and serum interleukin-6 (IL-6) and C-reactive protein (CRP) levels were assessed. Diurnal salivary dehydroepiandrosterone (DHEA) and IL-6 were also assessed in subgroups of patients. RESULTS: Median CRP and IL-6 measurements were about sixfold higher in patients than controls (both p < 0.001) Morning salivary cortisol levels did not differ between the two groups, but patients exhibited higher median levels of evening and nocturnal salivary cortisol compared to controls [0.391 (0.054, 0663) vs. 0.081 (0.054, 0.243) µg/dl, p < 0.001 and 0.183 (0.090, 0.834) vs. 0.054 (0.054, 0.332) µg/dl, p < 0.001, respectively], resulting in higher time-integrated area under the curve (AUC) (4.81 ± 2.46 vs. 2.75 ± 0.810, respectively, p < 0.001). Circulating ACTH, DHEA, and aldosterone levels were similar in patients and controls. Serum IL-6, but not ACTH levels, was strongly correlated with nocturnal cortisol salivary levels (ρ = 0.555, p < 0.001) in patients. CONCLUSIONS: Increased evening and nocturnal but not morning cortisol secretion may occur in even clinically mild COVID-19. In the context of acute viral infection (COVID-19), IL-6 may partially replace ACTH as a stimulus of the glucocorticoid-secreting adrenal zona-fasciculata without influencing the secretion of DHEA and aldosterone. CLINICAL TRIAL REGISTRATION: https://clinicaltrials.gov/ct2/show/NCT04988269?term=yavropoulou&draw=2&rank=3 (NCT04988269).

Inherited/Genetically-Associated Pheochromocytoma/ Paraganglioma Syndromes and COVID-19.

In some subjects with inherited pheochromocytoma/paraganglioma (PPG) syndromes, hypoxia-inducible factor 1 alpha (HIF1α) stabilization/activation could lead to an increase in angiotensin converting enzymes (ACE). This would result in the stimulation of angiotensin (AT) II production and, hence, reduce the availability of ACE 2. The latter would provide decreased numbers of binding sites for the spike protein of SARS-CoV-2 and, therefore, result in less points of viral entry into cells. Thus, subjects with HIF1α-associated PPG syndromes may benefit from an inherent protective effect against COVID-19. Such an implication of HIF1α vis-à-vis COVID-19 could open ways of therapeutic interventions.

MANAGEMENT OF ENDOCRINE DISEASE: Dysnatraemia in COVID-19: prevalence, prognostic impact, pathophysiology, and management.

This review examines the prevalence, aetiology, pathophysiology, prognostic value, and investigation of dysnatraemia in hospitalised COVID-19 patients, taking into account all relevant studies published in PubMed and Cochrane Library studies until March 2021. Hyponatraemia is commonly observed in patients with bacterial pneumonia and is an independent predictor for excess mortality and morbidity. However, it remains unknown whether this association applies to coronavirus disease-2019 (COVID-19). Several studies reported a 20-35% prevalence for hyponatraemia and 2-5% for hypernatraemia in patients admitted with COVID-19. In addition, hyponatraemia on admission was a risk factor for progression to severe disease, being associated with an increased likelihood for the need for invasive mechanical ventilation, with an odds ratio (OR) of 1.83-3.30. Hyponatraemia seems to be an independent risk factor for mortality, with an OR of 1.40-1.50 compared to normonatraemia, while hypernatraemia is related to even worse outcomes than hyponatraemia. Furthermore, preliminary data show an inverse association between serum sodium and interleukin-6 levels, suggesting that hyponatraemia might be used as a surrogate marker for the risk of a cytokine storm and the need for treatment with interleukin antagonists. In conclusion, dysnatraemia is common and carries a poor prognosis in COVID-19 patients, indicating that it may play a future role in risk stratification and individualising therapy.

Coronavirus disease 2019 in patients with neuroendocrine neoplasms: Preliminary results of the INTENSIVE study.

BACKGROUND: Specific data regarding coronavirus disease 2019 (COVID-19) in patients with neuroendocrine neoplasms (NENs) are lacking. The aim of this study is to describe the characteristics of patients with NENs who tested severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) positive. MATERIAL AND METHODS: This is a worldwide study collecting cases of patients with NENs along with a positive nasopharyngeal swab reverse transcriptase-polymerase chain reaction (RT-PCR) test for SARS-CoV-2 between June 1, 2020, and March 31, 2021. Centres treating patients with NENs were directly contacted by the principal investigator. Patients with NENs of any primary site, grade and stage were included, excluding small-cell lung carcinoma and mixed adenoneuroendocrine carcinoma. RESULTS: Among 81 centres directly contacted, 88.8% responded and 48.6% of them declined due to lack of cases or interest. On March 31st, 2021, eight recruiting centres enrolled 89 patients. The median age was 64 years at the time of COVID-19 diagnosis. Most patients had metastatic, non-functioning, low-/intermediate-grade gastroenteropancreatic NENs on treatment with somatostatin analogues and radioligand therapy. Most of them had comorbidities. Only 8% of patients had high-grade NENs and 12% were receiving chemotherapy. Most patients had symptoms or signs of COVID-19, mainly fever and cough. Only 3 patients underwent sub-intensive treatment, whereas most of them received medical therapies, mostly antibiotics. In two third of cases, no changes occurred for the anti-NEN therapy. More than 80% of patients completely recovered without sequelae, whereas 7.8% patients died due to COVID-19. CONCLUSIONS: Patients included in this study reflect the typical NEN population regardless of SARS-CoV-2. In most cases, they overcome COVID-19 without need of intensive care, short-term sequelae and discontinuation of systemic oncological therapy.

Impact of the COVID-19 pandemic on neuroendocrine tumour services in England.

PURPOSE: During the COVID-19 pandemic, there have been particular concerns regarding the related impact on specialist tumour services. Neuroendocrine tumour (NET) services are delivered in a highly specialised setting, typically delivered in a small number of centres that fulfil specific criteria as defined by the European Neuroendocrine Tumour Society (ENETS). We aimed to address the COVID-19-related impact on specialist NET tumour services in England and other countries. METHODS: Electronic survey addressing patient access and delivery of care distributed to all ENETS Centres of Excellence (CoE) in England and matching number of ENETS CoE elsewhere. Semi-quantitative and qualitative analyses of survey responses were performed. RESULTS: Survey response of ENETS CoE in England was 55% (6/11). Responses from six non-UK ENETS CoE elsewhere were received and analysed in a similar manner. Relevant disruption of various NET services was noted across all responding Centres, which included delayed patient appointments and investigations, reduced availability of treatment modalities including delayed surgical treatment and a major negative impact on research activities. The comparison between English and non-UK ENETS CoE suggested that the former had significantly greater concerns related to future research funding (p = 0.014), whilst having less disruption to multidisciplinary meetings (p = 0.01). A trend was also noted towards virtual patient appointments in ENETS CoE in England vs. elsewhere (p = 0.092). CONCLUSIONS: Restoration of highly specialised NET services following COVID-19 and planning for future service delivery and research funding must take account of the severe challenges encountered during the pandemic.