Measurement Of Aldosterone Research Articles

Hyperthermia as a Steroidogenic Inhibitor of Adrenodortical Cells, an Adrenal Sparing Treatment for Primary Aldosteronism?

Introduction: Primary Aldosteronism (PA) is the commonest secondary cause of hypertension. Mainstay therapy, adrenalectomy resects both hypersecreting and adjacent normal tissue. It is therefore only suitable for patients with unilateral disease (40% cases), whom are surgical candidates. Thermal therapy presents a plausible minimally invasive therapeutic, to target and disrupt hypersecreting adrenal nodules in primary aldosteronism, while also preserving adjacent normal adrenal cortex. Methodology: Adrenocortical cell lines (H295R and HAC15) were treated with hyperthermia using a water bath at temperatures between 37-650C for 15 minutes. Cell death and apoptosis were analysed immediately, 24 hours, and 48 hours post hyperthermia using Annexin V / Propidium Iodide (PI) (flow cytometry), and Calcein / PI imaging techniques. Steroidogenic potential was also analysed post hyperthermia by (i) measuring cytosolic calcium flux in response to angiotensin II (ANGII) using Flou-4 staining (flow cytometry); (ii) measurement of steroidogenic enzyme expression (RT-PCR); (iii) by measurement of cortisol and aldosterone in cell supernatants (chemiluminescent assays). Cells were also stimulated with forskolin for steroid enzyme and output assays. Results: Hyperthermia induced mainly necrotic cell death not apoptotic. Percentage cell death was significantly increased from 500C-65 0C (95.41+/- 5.74% versus control 9.17+/- 3.01%, p<0.0001). Cytosolic calcium changes in response to ANGII were lowered from 550C-650C in H295R (-36.33+/-7.06 Ca+ Response versus control 10.67+/- 1.76 Ca+ Response, p<0.001) and from 450C-650C in HAC15 (-43.33+/-12.36 Ca+ Response versus control 4.43+/-1.57 Ca+ Response, p<0.002), intracellular stored calcium was also diminished with increased hyperthermia exposures in both cell lines. CYP11B1 (-31.6+/-2.8 ααCt versus control, p<0.0001), CYP11B2 (-11.3+/-4.9 ααCt versus control, p<0.0001), and HSD3B2 (-42+/-9.8 ααCt versus control, p<0.0001) enzyme gene expression was decreased following 450C for 15 minutes in HAC15 cells while only CYP11B2 (-9.3+/-2.5 ααCt versus control, p<0.0001), and HSD3B2 (-15+/-1.3 ααCt versus control, p<0.0001) enzyme gene expression was decreased in H295R cells. Steroid output was also shown to be impaired at 450C for 15 minutes (22.35+/- 4.49 nmol/L versus control 117.7+/- 25 nmol/L, p<0.0001). Conclusion: Hyperthermic therapy delivered at sublethal temperatures and exposure times inhibits steroidogenesis. Inhibiting steroidogenesis by applying targeted thermal therapy to functional adrenocortical nodules represents a novel adrenal sparing approach to definitive management of primary aldosteronism.

Preventing the onset of diabetes-induced chronic kidney disease during prediabetes: The effects of oleanolic acid on selected markers of chronic kidney disease in a diet-induced prediabetic rat model

BackgroundThe prevalence of prediabetes correlates with increased incidence of chronic kidney disease (CKD). This study was aimed at investigating the effects of oleanolic acid (OA) on markers associated with CKD in the prediabetic rat model. MethodsPrediabetes was induced by exposing male Sprague Dawley rats (150–180 g) to high-fat high- carbohydrate (HFHC) diet for 20 weeks. The prediabetic animals were further subdivided according to their treatment and treated for 12 weeks with either OA (80 mg/kg p.o) or metformin (500 mg/kg p.o) both with and without dietary intervention. 24 h fluid intake and urine output were measured every fourth week of the treatment period while the urine samples were also used for podocin quantification through PCR. The animals were then sacrificed with urine, plasma and kidneys being harvested for biochemical analysis including the measurement of aldosterone, kidney-injury-molecule-1(KIM-1), blood and urine electrolytes, estimated glomerular filtration rate (eGFR), and albumin/creatinine (Alb/Cr) ratio. ResultsThis study observed that OA could reduce oxidative stress in the kidney while restoring plasma aldosterone and KIM-1 as well as urine electrolytes which were found to be augmented in prediabetic animals. This also correlated with normalization of GFR and Alb/Cr ratio in the OA-treated groups in both the absence and presence of dietary intervention. ConclusionsThese findings suggest that OA can ameliorate renal complications in a prediabetic rat model. However, more research is needed for the elucidation of molecular mechanisms behind these effects.

Requirement for oxytocin augmentation in spontaneous parturition is associated with the maternal serum steroid hormones assessed by liquid chromatography coupled to the tandem mass spectrometry.

The aim of research was to evaluate the maternal serum concentration of selected endogenous steroid hormones during spontaneous parturition at term and to determinate their association with the need for oxytocin augmentation. Blood of 108 healthy pregnant women whose parturition started with the regular spontaneous uterine contractions was drawn at the beginning of the labor. Liquid chromatography coupled to the tandem mass spectrometry device was utilized for measurement of sex hormone binding globulin, aldosterone, androstenedione, cortisol, cortisone, corticosterone, dehydroepiandrosterone, dehydroepiandrosteron sulphate, 17-hydroxyprogesterone, progesterone, and testosterone. Mann-Whitney U test, chi-square test, univariate and multivariate logistic regression, and receiver operating characteristic (ROC) analysis were used for the data analysis. Reference ranges of the selected hormones assessed by liquid chromatography coupled to the tandem mass spectrometry in maternal serum were established. Statistically significant differences in the serum concentration of corticosterone, dehydroepiandrosterone, and androstenedione between mothers requiring oxytocin augmentation and the rest of women having spontaneous parturition were found (p=0.002, p=0.008, and p=0.04, respectively). Concentrations were lower in the group of mothers who required oxytocin infusion for progression of labor. ROC analysis showed that all the mothers with dehydroepiandrosterone serum concentration above 21.6nmol/L have lower chance to use oxytocin infusion for the labor progression ( area under the curve (AUC) = 0.649, sensitivity=71.7%, specificity=59.6%, p=0.006). This research provided reference ranges for the selected maternal serum steroid hormones at the beginning of parturition. Association of corticosterone, dehydroepiandrosterone, and androstenedione with the need for the oxytocin infusion usage has been established. Dehydroepiandrosterone could be potential predictor of oxytocin infusion augmentation for progression of the parturition.

DEVELOPING A MOST EQUIVALENT ALDOSTERONE MEASUREMENT TO LC-MS/MS BY A NOVEL HIGH-QUANTITATIVE NONCOMPETITIVE CHEMILUMINESCENCE IMMUNOASSAY

Objective: Measurement of plasma aldosterone and renin concentration, or activity, is useful for selecting antihypertensive agents and detecting hyperaldosteronism in hypertensive patients. However, it takes several days to get results even if measured by inaccurate radioimmunoassay, or we must accept high-cost LC/MS, and development of a more rapid and accurate substitute has been long hoped. We have developed a novel, fully-automated, high-quantitative noncompetitive chemiluminescence immunoassay (NC-CLEIA) for detecting aldosterone in serum and plasma, and its performance is evaluated as compared to LC/MS measurement. Design and method: Recently a unique anti-metatype antibody, which recognizes the immunocomplex of aldosterone and its monoclonal antibody, was established. Using this antibody for sensing permitted the construction of non-competitive assay for the detection of aldosterone. The reaction protocol of novel aldosterone assay is the following. In the 1st reaction, aldosterone in patient's sample is captured on anti-body coated magnetic particles. Alkaline phosphatase-conjugated anti-metatype antibody is added and incubated as 2nd reaction following a wash. Then substrate solution is added after washing immunocomplex. The resulting reaction signals are proportional to the amount of aldosterone in the sample allowing quantitative determination of in serum or plasma sample. The overall reaction is completed within 30 min. Results: Limit of blank (LoB), limit of detection (LoD) and limit of quantitation (LoQ) of our NC-CLEIA aldosterone assay were 0.09 ng/dL, 0.21 ng/dL and 0.57 ng/dL, respectively. NC-CLEIA aldosterone measurements were linearly well correlated with LC/MS aldosterone measurements (N = 130, y = 1.027x - 0.23 ng/dL, Spearman's p = 0.996, p &lt; 0.0001). Bland-Altman plot analysis between NC-CLEIA and LC-MS/MS of aldosterone revealed a bias of 0.40 ng/dL with the limits of agreement of -4.60 and 5.41 ng/dL with 95% confidence interval. Conclusions: Our novel NC-CLEIA aldosterone assay was well-correlated and had only a very low bias with LC-MS/MS method and also was able to accurately quantify low level samples even in essential hypertension patients. This assay may be useful for the routine analysis of aldosterone and for the screening and diagnosis of PA from large number of hypertensive patients.

MicroRNA 21 and microRNA 155 levels in resistant hypertension, and their relationships with aldosterone

Aim MicroRNAs (miRNAs) are non-coding RNA molecules that serve as regulators following gene expression transcription. While studies have investigated the role of miRNAs in the pathogenesis of essential hypertension (HT), very few have considered their place in the pathogenesis of resistant hypertension (RH). The purpose of this study was to investigate levels of miRNA 21 and miRNA 155 in RH and their relationships with aldosterone. Method Thirty-two normotensive patients, 30 newly diagnosed HT patients, and 20 RH patients were included in the study. Patients’ demographic data were recorded, and office blood pressure measurement and 24-h ambulatory blood pressure monitoring (24-h ABPM) were performed. Blood specimens were collected for miRNA 21, miRNA 155 and aldosterone measurement. MiRNA 21 and miRNA 155 levels in the control and patient groups and their relations with other demographic and biochemical parameters were then subjected to analysis. Results No difference was determined in miRNA 155 levels between the groups, but miRNA 21 and aldosterone levels were significantly higher in the RH group (p < 0.001 and <0.05, respectively). At correlation analysis, miRNA 21 exhibited positive correlation with aldosterone, age, office SBP, 24-h ABPM all-day SBP. A 9.6 copy/uL level for miRNA 21 predicted presence or absence of RH with 95% sensitivity and 71% specificity (AUC:0.823, 95% CI (0.72–0.92). Conclusion The study results revealed significantly higher miRNA 21 and aldosterone in RH patients than in healthy individuals and newly diagnosed hypertensives.

Comparison of the Chemiluminescence Immunoassay LIAISON® with the Radioimmunoassay for Aldosterone and Renin Measurement.

Determination of renin plasma levels is useful in the diagnosis of hypertension and in the therapeutic follow-up of hypertensive patients. Plasmatic concentration of renin decreases in patients with hypertension due to a primary hyperaldosteronism, contrary to renovascular hypertension where concentrations of renin and aldosterone are both elevated. Blood samples (serum, EDTA plasma) were analysed using two different chemiluminiscent methods CLIA LIAISON® and radioimmunoassay for aldosterone (IMMUNOTECH Beckman Coulter) and renin (Cisbio Bioassay) measurements were compared. We used both methods to ascertain the correlation between serum vs. EDTA plasma levels of aldosterone (RIA, CLIA) and renin (IRMA, CLIA) and to compare aldosterone to renin ratios for CLIA and for radioimmunoassay: serum aldosterone to plasma renin and plasma aldosterone to plasma renin. We compared serum aldosterone CLIA vs. RIA (rP=0.933, P&lt;0.001) and plasma renin determined using CLIA vs. IRMA (rP=0.965, P=0.062). Furthermore, we used both methods to establish the correlation between the serum vs. plasma levels of aldosterone: RIA (rP=0.980, P&lt;0.001); CLIA (rP=0.994, P=0.353) and serum vs. plasma levels of renin: IRMA (rP=0.948, P&lt;0.001); CLIA (rP=0.921, P=0.011). Aldosterone (serum, plasma) to plasmatic renin ratios for CLIA (rP=0.999, P=0.286) and for radioimmunoassay (rP=0.992, P=0.025). Our data demonstrate that renin and aldosterone concentrations obtained using CLIA correlate with renin and aldosterone concentrations using radioimmunoassay methods. Correlation coefficients of pair results ranged from 0.921 to 0.994. Aldosterone (serum, EDTA plasma) to plasmatic renin ratios are comparable and any of them can be used with no significant differences found.

Intraindividual Variability of Aldosterone Concentrations in Primary Aldosteronism: Implications for Case Detection.

Primary aldosteronism is an underdiagnosed cause of hypertension. Although inadequate screening is one reason for underdiagnosis, another important contributor is that clinicians may inappropriately exclude the diagnosis when screening aldosterone concentrations fall below traditionally established thresholds. We evaluated the intraindividual variability in screening aldosterone concentrations and aldosterone-to-renin ratios, and how this variability could impact case detection, among 51 patients with confirmed primary aldosteronism who had 2 or more screening measurements of renin and aldosterone on different days. There were a total of 137 screening measurements with a mean of 3 (range 2-6) per patient. The mean intraindividual variability, expressed as coefficients of variation, was 31% for aldosterone and 45% for the aldosterone-to-renin ratio. Aldosterone concentrations ranged from 4.9 to 51 ng/dL; 49% of patients had at least one aldosterone measurement below 15 ng/dL, 29% had at least 2 aldosterone measurements below 15 ng/dL, and 29% had at least one measurement below 10 ng/dL. Individual aldosterone-to-renin ratios ranged from 8.2 to 427 ng/dL per ng/mL·hour; 57% had at least one ratio below 30 ng/dL per ng/mL·hour, 27% had at least 2 ratios below 30 ng/dL per ng/mL·hour, and 24% had at least one ratio below 20 ng/dL per ng/mL·hour. Aldosterone concentrations and aldosterone-to-renin ratios are highly variable in patients with primary aldosteronism, with many screening values falling below conventionally accepted diagnostic thresholds. The diagnostic yield for primary aldosteronism may be substantially increased by recalibrating the definition of a positive screen to include more liberal thresholds for aldosterone and the aldosterone-to-renin ratio.

Clinical Evaluation of Assays for Plasma Renin Activity and Aldosterone Measurement by Liquid Chromatography-Tandem Mass Spectrometry.

Aldosterone and renin are pivotal hormones in the regulation of salt and water homeostasis and blood pressure. Measurement of renin and aldosterone in serum/plasma is essential for the investigation of primary hyperaldosteronism (PA) and monitoring of glucocorticoid replacement therapy. We report 2 LC-MS/MS methods developed to measure aldosterone and plasma renin activity (PRA). PRA was determined by endogenous enzymatic generation of angiotensin I using 150 µL of sample. Generated angiotensin I was purified by solid phase extraction prior to chromatographic separation and mass spectrometry. Aldosterone measurement required 300 μL of sample extracted with MTBE prior to LC-MS/MS analysis. The PRA method was linear (1.2-193 nmol/L), sensitive (LLOQ = 1.2 nmol/L), precise (CV = 4.1%), and specific (no cross reactivity for a number of structurally similar steroids). Dilutional linearity and recovery (84%) were acceptable. Accuracy was confirmed by comparison against our current RIA method. The aldosterone method had equally acceptable performance characteristics. Reference ranges in 110 healthy normotensive subjects were: PRA 0.2-3.7 nmol/L/h and aldosterone 50-950 pmol/L. Consecutive patients (n = 62) with adrenal incidentalomas shown to have no functional adrenal disease; their post overnight 1 mg dexamethasone test values were: PRA 0.2-2.6 nmol/L/h and aldosterone 55-480 pmol/L. Serum aldosterone values after 2 liter saline suppression were-normal subjects (n = 17): 78-238 pmol/L and confirmed primary hyperaldosteronism (n = 25): 131-1080 pmol/L. We have developed robust assays for PRA and aldosterone with appropriate clinical evaluation. These assays are now in routine practice in the UK.

Variability of Aldosterone Measurements During Adrenal Venous Sampling for Primary Aldosteronism.

Variability of aldosterone concentrations has been described in patients with primary aldosteronism. We performed a retrospective cohort study of 340 patients with primary aldosteronism who underwent adrenal venous sampling (AVS) at a tertiary referral center, 116 of whom also had a peripheral venous aldosterone measured hours before the procedure. AVS was performed by the same interventional radiologist using bilateral, simultaneous sampling, under unstimulated and then stimulated conditions, and each sample was obtained in triplicate. Main outcome measures were: (i) change in day of AVS venous aldosterone from pre-AVS to intra-AVS and (ii) variability of triplicate adrenal venous aldosterone concentrations during AVS. Within an average duration of 131 minutes, 81% of patients had a decline in circulating aldosterone concentrations (relative decrease of 51% and median decrease of 7.0 ng/dl). More than a quarter (26%) of all patients had an inferior vena cava aldosterone of ≤5 ng/dl at AVS initiation. The mean coefficient of variation of triplicate adrenal aldosterone concentrations was 30% and 39%, in the left and right veins, respectively (corresponding to a percentage difference of 57% and 73%), resulting in lateralization discordance in up to 17% of patients if the lateralization index were calculated using only one unstimulated aldosterone-to-cortisol ratio rather than the average of triplicate measures. Circulating aldosterone levels can reach nadirs conventionally considered incompatible with the primary aldosteronism diagnosis, and adrenal venous aldosterone concentrations exhibit acute variability that can confound AVS interpretation. A single venous aldosterone measurement lacks precision and reproducibility in primary aldosteronism.

Prospective evaluation of aldosterone LC-MS/MS-specific cutoffs for the saline infusion test

Liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) has become state of the art for the quantitative analysis of steroid hormones. Although method comparisons show that aldosterone measurement using LC-MS/MS yields considerably lower levels than immunoassays (IAs), method-specific cutoff values for primary aldosteronism (PA) are largely missing. Objective of this study was to analyze the diagnostic accuracy of proposed LC-MS/MS-specific cutoff values for the saline infusion test (SIT). From 2016 to 2019, 104 consecutive patients suspected of PA underwent the SIT and captopril challenge test in the tertiary medical center at the University Hospital of Leipzig, Germany. Patients with positive case confirmation underwent adrenal imaging and adrenal venous sampling for subtype classification. Overall, proposed assay-specific PACLC-MS/MS cutoff values for the SIT achieved higher diagnostic accuracy than established PACIA values with a sensitivity and specificity of 87.5% (95% CI: 71.0-96.5) and 97% (95% CI: 89.6-99.6) for a cutoff of 120 pmol/L and 93.8% (95% CI: 79.2-99.2) and 92.5% (95% CI: 83.4-97.5) for a cutoff of 94 pmol/L. The most accurate post-SIT PACLC-MS/MS cutoff value in this study was 83 pmol/L, yielding a sensitivity and specificity of 96.9% (95% CI: 83.8-99.9) and 92.5% (95% CI: 83.4-97.5), respectively. The present data confirm the need for the implication of lower method-specific aldosterone cutoff values for the diagnosis of PA with LC-MS/MS based aldosterone measurement.

Reassessment of Urinary Aldosterone Measurement After Saline Infusion in Primary Aldosteronism.

ContextUrinary aldosterone levels (Uald) are widely measured in the oral sodium-loading test to confirm primary aldosteronism (PA), but reliable studies on their diagnostic value are limited. This may be due to the difficulty in collecting urine with reliable accuracy, keeping oral sodium intake constant between patients. Therefore, we focused on 24-hour Uald after intravenous saline infusion in a hospitalized setting, which provides a reliable sodium load in consistent amounts.ObjectiveComparing plasma aldosterone concentrations (PAC) and Uald after saline infusion in the sitting position, to evaluate the accuracy in determining PA subtypes and the correlation of both measurements.Design and SettingThis was a retrospective cross-sectional study in a single referral center.PatientsOf 53 patients without renal dysfunction who were diagnosed with PA and underwent adrenal venous sampling, 16 and 37 were diagnosed with unilateral and bilateral PA, respectively.Main Outcome MeasuresUald collected for 24 hours and PAC after saline infusion.ResultsThe area under the receiver operating characteristic curve for diagnosing unilateral PA was not significantly different between Uald and PAC after saline infusion (0.921 and 0.958, respectively; P = 0.370). The predicted optimal cutoff value of Uald was 16.5 μg/day (sensitivity, 87.5%; specificity, 100%), and that of PAC after saline infusion was 19.3 ng/dL (sensitivity, 87.5%; specificity, 97.3%). In studied patients with PA, Uald was positively correlated with PAC after saline infusion (r = 0.617; P < 0.001).ConclusionsWe reassessed Uald in PA patients under sufficient sodium loading and demonstrated the correlation between Uald and PAC after saline infusion.

Serum Aldosterone Concentration, Blood Pressure, and Coronary Artery Calcium: The Multi-Ethnic Study of Atherosclerosis.

Aldosterone is a steroid hormone regulating fluid and electrolyte homeostasis and is known to increase the risk of atherosclerosis. In this study, we examined the associations of serum aldosterone concentrations with subclinical atherosclerosis and all-cause mortality. This study included 948 adults aged 46 to 88 years from the MESA (Multi-Ethnic Study of Atherosclerosis) with measurements of serum aldosterone and plasma renin activity and not taking antihypertensive medications. Coronary calcification was longitudinally assessed using Agatston coronary artery calcium score from computed tomography scans. All-cause mortality was ascertained from the medical record. The average age (SD) was 62.3 (9.4) years and 53% were male. Among 700 subjects who had follow-up coronary artery calcium score (median follow-up of 6.4 years), higher aldosterone levels (per 100 pg/mL) were associated with higher coronary artery calcium (relative ratio, 1.17 [95% CI, 1.04-1.32]), with the association being stronger in individuals with suppressed plasma renin activity (≤0.5 μg/L/hr). Systolic or diastolic blood pressure mediated around 45% of the total effect of aldosterone on coronary artery calcium. Over a median follow-up of 12.5 years (120 deaths identified among 948 subjects), aldosterone was associated with the increased risk of all-cause mortality when plasma renin activity was suppressed; hazard ratio per 100 pg/mL, 1.70 (95% CI, 1.10-2.63). In this study, we found that higher aldosterone levels were associated with the increased risk of subclinical coronary atherosclerosis and all-cause mortality particularly when renin was suppressed. Our findings indicate the importance of aldosterone levels (even within the reference range) with respect to the cardiovascular system and overall health.

SUN-LB95 Developing a Highly Equivalent Non-Competitive Chemiluminescence Immunoassay Aldosterone Measurement to LC/MS

Background Measurement of plasma aldosterone and renin concentration, or activity, is useful for selecting antihypertensive agents anddetecting hyperaldosteronism in hypertensive patients. However, it takes several days to get results even if measured by inaccurateradioimmunoassay, or we must accept high-cost LC/MS, and development of a more rapid and accurate substitute has been long hoped. We havedeveloped a novel, fully-automated, high-quantitative noncompetitive chemiluminescence immunoassay (NC-CLEIA) for detecting aldosterone inserum and plasma, and its performance is evaluated as compared to LC/MS measurement. Methods Recently a unique anti-metatype antibody,which recognizes the immunocomplex of aldosterone and its monoclonal antibody, was established. Using this antibody for sensing permittedthe construction of non-competitive assay for the detection of aldosterone. The reaction protocol of novel aldosterone assay is the following. Inthe 1st reaction, aldosterone in patient’s sample is captured on anti-body coated magnetic particles. Alkaline phosphatase-conjugated antimetatypeantibody is added and incubated as 2nd reaction following a wash. Then substrate solution is added after washing immunocomplex.The resulting reaction signals are proportional to the amount of aldosterone in the sample allowing quantitative determination of in serum orplasma sample. The overall reaction is completed within 30 min. Results Limit of blank (LoB), limit of detection (LoD) and limit of quantitation(LoQ) of our NC-CLEIA aldosterone assay were 0.09 ng/dL, 0.21 ng/dL and 0.57 ng/dL, respectively. NC-CLEIA aldosterone measurements werelinearly well correlated with LC/MS aldosterone measurements (N = 130, y = 1.027x - 0.23 ng/dL, Spearman’s ρ = 0.996, P< 0.0001). Bland-Altmanplot analysis between NC-CLEIA and LC-MS/MS of aldosterone revealed a bias of 0.40 ng/dL with the limits of agreement of -4.60 and 5.41 ng/dLwith 95% confidence interval. Conclusion Our novel NC-CLEIA aldosterone assay was well-correlated and had only a very low bias with LC-MS/MSmethod and also was able to accurately quantify low level samples even in essential hypertension patients. This aldosterone assay can be a most equivalent to LC-MS/MS measurement with a low cost of 12 $ and a short measuring time of 30 minutes.

SAT-543 Human Hair Aldosterone Measurements for Evaluation of Primary Aldosteronism

Background: Primary Aldosteronism (PA) is the most common cause of endocrine hypertension in US. Diagnostic techniques such as a 24 hour urine collection or saline suppression test (SST) can be laborious for both patients and staff. Our group previously showed that human hair cortisol measurements correlated with urine and serum cortisol levels in patients with endogenous cortisol excess. In this study, we explored whether human hair aldosterone correlated with other measures of aldosterone production. Methods: 41 adult subjects were evaluated at the NIH Clinical Center for adrenal disorders. A pencil-width of hair near the occiput was removed, and the 1cm segment closest to the scalp was analyzed by enzyme immunoassay for aldosterone, reported as pg aldosterone/mg dry hair. Not all subjects underwent complete workup for PA. Data were transformed as necessary to maintain assumptions of normality. Student’s t-test and Pearson correlations were used for statistical analysis. Results: Of the evaluated subjects, 18 were diagnosed with PA, 22 subjects did not have PA, and 1 subject was indeterminate. The mean hair weight was 33.0±13.7mg. For hair samples weighing greater than 10mg, hair weight was not correlated with hair aldosterone concentration (p=0.40). There was no difference in measured hair aldosterone between the subjects with and without PA (2.01±1.09 vs. 2.52±2.45 pg/mg; p=0.82). Among all subjects, hair aldosterone did not correlate with serum aldosterone (p=0.92), aldosterone-to-renin ratio (ARR; p=0.94), 24 hour urine aldosterone (Ualdo; p=0.85), or the serum aldosterone at the 4 hour time point of a SST (4hrAldo; p=0.98). Serum aldosterone, ARR, Ualdo, and 4hrAldo all correlated highly amongst each other (all p’s<0.001). Conclusions: Hair aldosterone levels do not correlate with other markers of PA. Further work is needed to understand whether optimization of study conditions could improve the usefulness of hair aldosterone measurements in the evaluation of PA.

Clinical determinants and prognostic implications of renin and aldosterone in patients with symptomatic heart failure.

AimsActivation of the renin–angiotensin–aldosterone system plays an important role in the pathophysiology of heart failure (HF) and has been associated with poor prognosis. There are limited data on the associations of renin and aldosterone levels with clinical profiles, treatment response, and study outcomes in patients with HF.Methods and resultsWe analysed 2,039 patients with available baseline renin and aldosterone levels in BIOSTAT‐CHF (a systems BIOlogy study to Tailored Treatment in Chronic Heart Failure). The primary outcome was the composite of all‐cause mortality or HF hospitalization. We also investigated changes in renin and aldosterone levels after administration of mineralocorticoid receptor antagonists (MRAs) in a subset of the EPHESUS trial and in an acute HF cohort (PORTO). In BIOSTAT‐CHF study, median renin and aldosterone levels were 85.3 (percentile25–75 = 28–247) μIU/mL and 9.4 (percentile25–75 = 4.4–19.8) ng/dL, respectively. Prior HF admission, lower blood pressure, sodium, poorer renal function, and MRA treatment were associated with higher renin and aldosterone. Higher renin was associated with an increased rate of the primary outcome [highest vs. lowest renin tertile: adjusted‐HR (95% CI) = 1.47 (1.16–1.86), P = 0.002], whereas higher aldosterone was not [highest vs. lowest aldosterone tertile: adjusted‐HR (95% CI) = 1.16 (0.93–1.44), P = 0.19]. Renin and/or aldosterone did not improve the BIOSTAT‐CHF prognostic models. The rise in aldosterone with the use of MRAs was observed in EPHESUS and PORTO studies.ConclusionsCirculating levels of renin and aldosterone were associated with both the disease severity and use of MRAs. By reflecting both the disease and its treatments, the prognostic discrimination of these biomarkers was poor. Our data suggest that the “point” measurement of renin and aldosterone in HF is of limited clinical utility.

Clinical utility value of urinary aldosterone detection by tandem mass spectrometry in primary hyperaldosteronism screening

Objective To explore the clinical utility of liquid chromatography tandem mass spectrometry forprimary aldosteronism screening. Methods From January to October 2019, 413 inpatients diagnosed hypertension from Fuwai Hospital of Chinese Academy of Medical Sciences were enrolled, including 60 Primary aldosteronism(PA)patients and 353 primary hypertension patients. The plasma aldosterone concentration (PAC) and renin concentration (DRC) were measured after 2 h of standing. The 24 h urine samples were collected for measurement of aldosterone using LC-MS/MS. The performance of urine aldosterone and urine aldosterone/renin ratio (UADRR) in PA screening was evaluated by ROC, and compared with PAC/DRC ratio (ADRR). Meanwhile, the efficiency of urine aldosterone in elderly patients or patients with low blood potassium or 24 h urine sodium over 200 mmol was investigated. Results Area under the curve (AUC)of urine aldosterone was 0.725 (95%CI 0.679-0.767), and the best cut-off was 7.13 μg/24 h, which was lower than AUC of ADRR (0.958, 95%CI 0.934-0.975). The AUC of UADRR was 0.947 (95%CI 0.920-0.966), the best cut-off was 1.11 (μg/24 h)/(μIU/ml), the sensitivity and specificity were 91.7% and 89.0%, respectively. There is no significant differences found with ADRR. In patients with 24 h urine sodium over 200 mmol, AUC of aldosterone was 0.834 (95%CI 0.730-0.910) and the best cut-off was 9.31 μg/24 h. The sensitivity and specificity were 90.9% and 68.7%, respectively. For the elderly patients over 60 years old, the AUC of urinary aldosterone was 0.860 (95%CI 0.770-0.925), and the best cut-off was 6.91 μg/24 h. The sensitivity and specificity were 84.6% and 81.3%, respectively. When admission blood potassium was less than 3.50 mmol/L, AUC of urinary aldosterone was 0.822 (95%CI 0.684-0.917), and the best cut-off was 10.63 μg/24 h. The sensitivity and specificity were 85.7% and 66.7%, respectively. Conclusion The detection of aldosterone in urine by LC-MS/MS can provide clinical information for PA screening, and the screening performance is better in patients with 24-hour urine sodium over 200 mmol, elderly patients or patients with low blood potassium. If combined with renin, screening efficiency was the same as that in ADRR. Key words: Hyperaldosteronism; Aldosterone; Urinalysis; Tandem mass spectrometry; Chromatography, liquid

Evaluation of analytical performance of Accuraseed, a fully automated chemiluminescent enzyme immunoassay machine: ARC and aldosterone measurements

Evaluation of analytical performance of Accuraseed, a fully automated chemiluminescent enzyme immunoassay machine: ARC and aldosterone measurements

Solving a myth: Does boric acid stabilize aldosterone in urine at typical clinical laboratory storage conditions?

Aldosterone is produced by the adrenal gland and plays an important role in blood pressure regulation and electrolyte hemostasis. Clinically, measurement of urine aldosterone provides evidence for the diagnosis of hyper- and hypo-aldosteronism. Urine specimen that is collected in consecutive 24 h is preferred, which mitigates the risk of misdiagnosis due to large diurnal variation in aldosterone secretion. Preservatives such as boric acid are routinely added to the collection containers prior to urine collection. However, little is known of the effectiveness of these preservatives on stabilizing aldosterone in urine. In the current study, we examined the stability of urine aldosterone under typical clinical laboratory storage conditions with and without the supplementation of boric acid. Our result demonstrated that the addition of boric acid is unnecessary.

Comparison of ID-LC-MS/MS and two CLIAs in measuring plasma aldosterone

Objective Accurate measurement of aldosterone is critical in the diagnosis of primary aldosteronism. We compared the harmonization of three assays including isotope dilution liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) and two chemiluminescence immunoassays (CLIAs: system A and system B) for the aldosterone measurement. Methods A total of 45 plasma samples, 4 quality control materials, 5 lyophilized bovine serums, and 3 fresh frozen human serum pools were measured by three assays respectively. Based on CLSI EP15-A3 rule, the precision was assessed by coefficient of variance. Deming regression and Bland & Altman plots was performed for method comparison, and correlation coefficient was calculated for concordance (CCC). Results All three methods met the performance criteria based on desirable biological variation for precision (<7.35%). System A showed a relevantly good correlation and comparability with ID-LC/MS/MS (R2=0.985, CCC=0.967), while System B showed relevantly bad correlations and comparability with both System A (R2=0.538, CCC=0.605) and ID-LC/MS/MS (R2=0.547, CCC=0.528).. However, the average relevant bias of two CLIAs exceeded the bias requirement derived from biological variation (18.60%). Conclusion Significant differences were found in the measurement of plasma aldosterone using ID-LC-MS/MS and two CLIAs, which urges the establishment of traceability hierarchy and improvement of reagents' specificity for standardization of aldosterone measurement in clinical settings. Key words: Aldosterone; Luminescence; Immunoassay; Chromatography, liquid; Tandem mass spectrometry

CLINICAL VALIDATION OF THE NEW AUTOMATED ALDOSTERONE LIAISON XL ASSAY ON THE ADRENAL VEIN SAMPLING CONFIRMATORY TEST

Objective: Measurement of aldosterone is the cornerstone in Primary aldosteronism (PA) workup, for both screening and final diagnosis (as confirmatory test). Albeit several automated aldosterone chemiluminescent assays have become recently available as reliable alternatives to the well-established radioimmunometric methods (RIA), little information is available on the diagnostic performance of the former methods using samples collected by adrenal vein sampling (AVS). AVS for aldosterone measurement is still considered the ‘gold standard’ procedure to differentiate aldosterone-producing adenoma (APA) and bilateral idiopathic hyperaldosteronism (IHA). This study was aimed to assess the clinical utility of the new Aldosterone Liaison XL assay for AVS sampling compared with a traditional RIA method. Design and method: The study population consisted of 12 patients (10 males and 2 females) undergoing AVS, Aldosterone was measured with RIA (DSL800, Beckman coulter), and Liaison XL (Diasorin). Samples were taken step by step from both adrenal veins, and the superior and inferior vena cava (upper and below renal vein). Results: Results of serum samples (n = 46) were analysed. The median values (2.5–97.5 percentiles) for RIA and Liaison XL were 289 ng/mL (58–48550 pg/mL) and 203 ng/mL (64–39689 pg/mL), respectively. The nonparametric regression of Passing & Bablok and the Spearman's correlation showed excellent performance for Liaison XL Aldosterone compared to RIA (Liaison XL = 0,48 x RIA + 30.5; r = 0.95, p < 0.001). In all patients the lateralization ratio with RIA were confirmed with Liaison XL method. (7 patients had IHA; APA were 2 right and 3 left, respectively) Conclusions: The rate of lateralization at AVS is identical when either RIA or LIAISON XL are used for aldosterone determination. We therefore conclude that the new Liaison XL Aldosterone is a suitable assay for the rapid quantification for the AVS procedure.