Stephanie Baron

BACKGROUND: Somatic aldosterone-driver mutations are identified in >90% of patients with primary aldosteronism undergoing adrenalectomy, and they display distinct demographic clustering. ATP1A1 and ATP2B3 mutations, encoding the Na ⁺ /K ⁺ ATPase α1 subunit and the Ca ²⁺ ATPase 3, respectively, are relatively rare and are often grouped as ATPase mutations. Differences in their clinical and biochemical phenotypes remain understudied. METHODS: This international collaboration of 16 centers included patients with primary aldosteronism harboring pathogenic variants in ATP1A1 and ATP2B3 . Clinical data were collected from medical records. Where available, we compared histopathologic features and steroid profiles (from peripheral and adrenal vein samples) by liquid chromatography-tandem mass spectrometry. RESULTS: We included 300 patients (mean age, 57±11 years; 85% men) with aldosterone-producing lesions harboring ATP1A1 (204) and ATP2B3 (96) mutations. Age and sex distributions were similar. ATP2B3 mutations were associated with lower serum potassium, higher lateralization indices, and stronger contralateral suppression. Postoperative biochemical cure was achieved in 96% of patients with ATP2B3 mutations versus 83% of those with ATP1A1 mutations ( P =0.02). Multiple CYP11B2-positive lesions were observed in 47% of ATP1A1 versus 27% of ATP2B3 cases ( P =0.03). Baseline peripheral steroid profiling was available in 126 patients (84 with ATP1A1 and 42 with ATP2B3 ) and showed higher aldosterone concentrations in the ATP2B3 group (median [interquartile range], 31 ng/dL [20–43] versus 23 ng/dL [11–38]; P =0.03). CONCLUSIONS: ATP ase mutations are most common in middle-aged men with lateralized primary aldosteronism. Compared with ATP1A1 , ATP2B3 mutations are associated with a more severe primary aldosteronism phenotype, stronger lateralization, and higher rates of single aldosterone-producing lesions and postoperative biochemical cure.

Le vieillissement de la population est le résultat de l’amélioration de la prise en charge des individus, en particulier des sujets âgés, conduisant à l’apparition d’une nouvelle catégorie démographique, le quatrième âge avec les plus de 75 ans. Cette population polypathologique présente de nombreuses spécificités, avec entre autres, une intolérance au glucose, un état de dénutrition et une altération des fonctions cardiovasculaires, les maladies cardiovasculaires restant la première cause de mortalité dans cette tranche d’âge. Comme évoqué dès les années 50 par Harman, le stress oxydant pourrait jouer un rôle important dans l’ensemble de ces comorbidités. Le resvératrol, un polyphénol anti-oxydant connu pour ses biens-faits cardiovasculaires pourrait ainsi être une molécule d’intérêt dans ce contexte. Nos objectifs dans ce travail ont donc été d’évaluer les effets d’un traitement chronique par le resvératrol accompagné ou non d’une prise en charge nutritionnelle chez la souris très âgée. Ces effets du resvératrol ont été étudiés aussi bien sur le plan métabolique que sur le phénotype cardiovasculaire. Nos résultats montrent qu’un régime riche en protéines et pauvre en glucides a des effets variables en fonction de l’âge. Sans effet sur la souris jeune, il devient délétère chez la souris adulte et très âgée avec une majoration de l’altération de l’homéostasie glucidique associée à une détérioration du bilan lipidique. Ces dysrégulations métaboliques ont pour conséquence une dégradation accrue des fonctions artérielles et cardiaques. Chez la souris très âgée, un traitement par le resvératrol amplifie les dommages liés à ce régime en accentuant les altérations métaboliques et cardiovasculaires, soulignant, et ce pour la première fois, de potentiels effets délétères du resvératrol dans le cadre du vieillissement. En revanche, chez la souris âgée dénutrie en l’absence de prise en charge nutritionnelle, le resvératrol présente des effets bénéfiques avec une amélioration de l’insulino-sensibilité et des fonctions artérielles, associée à une modification d’expression de TXNIP, protéine à l’interface de la régulation de l’homéostasie du glucose et de la balance oxydative, faisant d’elle une piste à explorer tant pour expliquer certains mécanismes impliqués dans le vieillissement que dans les effets du resvératrol.

BACKGROUND: Primary aldosteronism is the most common form of secondary hypertension. The most frequent genetic cause of aldosterone-producing adenomas is somatic mutations in the potassium channel KCNJ5. They affect the ion selectivity of the channel, with sodium influx leading to cell membrane depolarization and activation of calcium signaling, the major trigger for aldosterone biosynthesis. METHODS: To investigate how KCNJ5 mutations lead to the development of aldosterone-producing adenomas, we established an adrenocortical cell model in which sodium entry into the cells can be modulated on demand using chemogenetic tools [H295R-S2 α7-5HT3-R (α7-5HT3 receptor) cells]. We investigated their functional and molecular characteristics with regard to aldosterone biosynthesis and cell proliferation. RESULTS: A clonal cell line with stable expression of the chimeric α7-5HT3-R in H295R-S2 (human adrenocortical carcinoma cell line, Strain 2) cells was obtained. Increased sodium entry through α7-5HT3-R upon stimulation with uPSEM-817 (uPharmacologically Selective Effector Molecule-817) led to cell membrane depolarization, opening of voltage-gated Ca ²⁺ channels, and increased intracellular Ca ²⁺ concentrations, resulting in the stimulation of CYP11B2 expression and increased aldosterone biosynthesis. Increased intracellular sodium influx did not increase proliferation but rather induced apoptosis. RNA sequencing and steroidome analyses revealed unique profiles associated with Na ⁺ entry, with only partial overlap with Ang II (angiotensin II) or potassium-induced changes. CONCLUSIONS: H295R-S2 α7-5HT3-R cells are a new model reproducing the major features of cells harboring KCNJ5 mutations. Increased expression of CYP11B2 and stimulation of the mineralocorticoid biosynthesis pathway are associated with a decrease of cell proliferation and an increase of apoptosis, indicating that additional events may be required for the development of aldosterone-producing adenomas.

Objectives: Primary aldosteronism (PA) diagnosis is a multistep process that begins with screening based on the plasma aldosterone-to-renin ratio (ARR). As cut-off values depend on the methods used, the aim of this study was 1) to validate the performances of new aldosterone and renin chemiluminescent immuno-assays using the Lumipulse^® analyzer (Fujirebio^®) and then 2) to define the criteria to distinguish PA patients from those with essential hypertension (EH). Methods: This monocentric retrospective study included 297 patients admitted to Georges Pompidou European Hospital, France, between January 2021 and December 2022 for the assessment of hypertension etiology. We evaluated analytical performances and compared Lumipulse^® results for plasma renin (PRC) and plasma aldosterone (PAC) concentrations (n = 196) as well as 24-hour urine aldosterone excretion (24UA) (n = 201) to the reference methods (PRC: Liaison XL^® Diasorin^®; PAC and 24UA: LC-MS/MS). Receiver operating characteristic curve analysis was used to define the cut-off values for ARR, PAC, and 24UA to distinguish between PA and EH patients. Results: Analytical characteristics were in accordance with requested performances. Our results showed excellent correlations between Lumipulse^® and our reference methods. We propose cut-off values of 35 pmol/mIU as the ARR, 260 pmol/L for PAC, and 49 nmol/24h for 24UA for predicting PA diagnosis. Conclusions: Lumipulse^® (Fujirebio^®) is a reliable alternative for measuring PRC, PAC, and 24UA for predicting PA diagnosis with the use of corresponding cut-off values for each criterion.

BACKGROUND: The prevalence of secondary causes of hypertension in young adults is unknown, and therefore, there is no consensus about the indication of screening of secondary hypertension (2HTN) in this population. The objective was to report the prevalence and the causes of 2HTN in young subjects. METHODS: In this cross-sectional study, 2090 patients with confirmed hypertension aged 18 to 40 years with full workup for 2HTN screening were included. We assessed the prevalence of 2HTN and analyzed the factors associated. RESULTS: Among 2090 patients, 619 (29.6%) had a 2HTN. The most frequent diagnoses of 2HTN in descending order were primary aldosteronism (n=339; 54.8%), renovascular hypertension (n=114; 18.4%), primary kidney disease (n=80; 12.9%), pheochromocytoma/functional paraganglioma (n=37; 5.9%), hypertension caused by drugs or substances (n=32; 6.0%), and other diagnoses (n=17; 2.7%). Patients with blood pressure P =0.024). Female sex, hypokalemia, treatment with at least 2 medications, no familial history of hypertension, body mass index <25 kg/m², and diabetes were associated with a higher prevalence of 2HTN. CONCLUSIONS: The prevalence of 2HTN is high among young patients with hypertension (29.6% in our cohort), regardless of age and blood pressure level. All patients with hypertension under 40 years of age should be screened for secondary causes.

Pathology and biology are essential in the patient care. However, they suffer from a lack of attractiveness to medicine students. In order to gain insight and improve the visibility and attractiveness of these specialties, we designed a survey and submitted forms to medical students, laboratory medical staff, and clinical staff from the different hospitals and institutes attached to "Université Paris Cité". The responses (363 students (response rate: 9.1%), 109 medical -laboratory staff (25%), 61 clinical staff (10%)) confirmed the poor visibility of these specialties among students as well as the will of the -medical laboratory staff to be more involved in the student's training. The -development of partnerships between laboratories and clinical -departments, which would allow medical students to spend short periods of time in related laboratories during their clinical internship, is a prospect for improving the teaching of these disciplines. The main expected benefits are to "discover a new specialty" and "to better understand the prescription of laboratory tests", which are crucial aspects for understanding the role of laboratory disciplines and their interaction with clinicians to improve patient care.

Nephrolithiasis affects around 10% of the population and is frequently associated with impaired dietary factors. The first one is insufficient fluid intake inducing reduced urine volume, urine supersaturation, and subsequently urinary lithiasis. Kidneys regulate 24 h urine volume, which, under physiological conditions, approximately reflects daily fluid intake. The aim of this study is to synthesize and highlight the role of hydration in the treatment of nephrolithiasis. Increasing fluid intake has a preventive effect on the risk of developing a first kidney stone (primary prevention) and also decreases the risk of stone recurrence (secondary prevention). Current guidelines recommend increasing fluid intake to at least at 2.5 L/day to prevent stone formation, and even to 3.5–4 L in some severe forms of nephrolithiasis (primary or enteric hyperoxaluria or cystinuria). Fluid intake must also be balanced between day and night, to avoid urinary supersaturation during the night. Patients should be informed and supported in this difficult process of increasing urine dilution, with practical ways and daily routines to increase their fluid intake. The liquid of choice is water, which should be chosen depending on its composition (such as calcium, bicarbonate, or magnesium content). Finally, some additional advice has to be given to avoid certain beverages such as those containing fructose or phosphoric acid, which are susceptible to increase the risk of nephrolithiasis.

Nephrolithiasis affects around 10% of the population and is frequently associated with impaired dietary factors. The first one is insufficient fluid intake inducing reduced urine volume, urine supersaturation, and subsequently urinary lithiasis. Kidneys regulate 24-hour urine volume, which, under physiological conditions, approximately reflect daily fluid intake. Increasing fluid intake has a preventive effect on the risk of developing a first kidney stone (primary prevention) but also decreases the risk of stone recurrence (secondary prevention). Current guidelines recommend increasing fluid intake at least at 2.5L /day to prevent stone formation, and even at 3.5-4L in some severe forms of nephrolithiasis (primary or enteric hyperoxaluria or cystinuria). Fluid intake must also be balanced between day and night, to avoid urinary supersaturation during the night. Patients should be informed and supported in this difficult process of increasing urine dilution, with practical ways and daily routines to increase their fluid intake. The liquid of choice is water, which should be chosen depending on its composition (such as calcium, bicarbonate or magnesium content). Finally, some additional advices have to be given to avoid some beverages such as those containing fructose or phosphoric acid, which are susceptible to increase the risk of nephrolithiasis.

Maintenance of hydration status requires a tight balance between fluid input and output. An increase in water loss or a decrease in fluid intake is responsible for dehydration status, leading to kidney water reabsorption. Thus, urine volume decreases and concentration of the different solutes increases. Urine dilution is the main recommendation to prevent kidney stone recurrence. Monitoring hydration status and urine dilution is key to preventing stone recurrence. This monitoring could either be performed via spot urine or 24 h urine collection with corresponding interpretation criteria. In laboratory conditions, urine osmolality measurement is the best tool to evaluate urine dilution, with less interference than urine-specific gravity measurement. However, this evaluation is only available during time lab examination. To improve urine dilution in nephrolithiasis patients in daily life, such monitoring should also be available at home. Urine color is of poor interest, but reagent strips with urine-specific gravity estimation are currently the only available tool, even with well-known interferences. Finally, at home, fluid intake monitoring could be an alternative to urine dilution monitoring. Eventually, the use of a connected device seems to be the most promising solution.

Introduction: Osilodrostat is a new 11β-hydroxylase inhibitor with a mode of action analogous to Metyrapone. The objective of this study was to compare steroidogenic profiles in patients treated with either Osilodrostat or Metyrapone for adrenocorticotrophic hormone (ACTH)-dependent Cushing's syndrome (CS). Methods: Patients followed up at Cochin hospital Endocrinology department between March 2019 and December 2021 for an ACTH-dependent CS, controlled by either Osilodrostat or Metyrapone, were included. A serum profile of five steroids (cortisol, 11-deoxycortisol, 17-hydroxyprogesterone, androstenedione and testosterone) was determined using UPLC- tandem mass spectrometry (UPLC-MS/MS). Results: Nineteen patients treated with Osilodrostat, eight patients treated with Metyrapone and six patients treated with consecutive Metyrapone then Osilodrostat were included. Hypocortisolism (basal cortisol <100 nmol/L) was found in 48% of patients treated with Osilodrostat and 7% of patients treated with Metyrapone. 11-deoxycortisol and androstenedione levels were higher in patients treated with Metyrapone (80.9 (2.2–688.4) and 14.9 (2.5–54.3) nmol/L, respectively) than in patients treated with Osilodrostat (10.3 (0.5–71.9) and 4.0 (0.3–13.3) nmol/L) (P = 0.0009 and P = 0.0005). Testosterone level in women was also higher in Metyrapone group (3.3 (0.93–4.82) nmol/L vs 1.31(0.13–5.09) nmol/L, P = 0.0146). CYP11B1 activity (11-deoxycortisol/cortisol) was not significantly different between the two groups. CYP21A2 activity (17OHprogesterone/11-deoxycortisol) and CYP17A1 activity (17OHprogesterone/androstenedione) were significantly decreased in Osilodrostat group (P < 0.0001). Conclusion: In patients with ACTH-dependent CS, the use of CYP11B1 inhibitors in routine care suggests that Osilodrostat has a less specific effect on the inhibition of steroidogenic enzymes than Metyrapone. This might explain a smaller increase in 11-deoxycortisol and androgen levels in patients treated with Osilodrostat.