Screening for Primary Aldosteronism by Mass Spectrometry Versus Immunoassay Measurements of Aldosterone: A Prospective Within-Patient Study.

BACKGROUND: Measurements of aldosterone by mass spectrometry are more accurate and less prone to interferences than immunoassay measurements, and may produce a more accurate aldosterone:renin ratio (ARR) when screening for primary aldosteronism (PA). METHODS: Differences in diagnostic performance of the ARR using mass spectrometry vs immunoassay measurements of aldosterone were examined in 710 patients screened for PA. PA was confirmed in 153 patients and excluded in 451 others. Disease classifications were not achieved in 106 patients. Areas under receiver-operating characteristic curves (AUROC) and other measures were used to compare diagnostic performance. RESULTS: Mass spectrometry-based measurements yielded lower plasma aldosterone concentrations than immunoassay measurements. For the ARR based on immunoassay measurements of aldosterone, AUROCs were slightly lower (P = 0.018) than those using mass spectrometry measurements (0.895 vs 0.906). The cutoff for the ARR to reach a sensitivity of 95% was 30 and 21.5 pmol/mU by respective immunoassay and mass spectrometry-based measurements, which corresponded to specificities of 57% for both. With data restricted to patients with unilateral PA, diagnostic sensitivities of 94% with specificities >81% could be achieved at cutoffs of 61 and 52 pmol/mU for respective immunoassay and mass spectrometry measurements. CONCLUSIONS: Mass spectrometry-based measurements of aldosterone for the ARR provide no clear diagnostic advantage over immunoassay-based measurements. Both approaches offer limited diagnostic accuracy for the ARR as a screening test. One solution is to employ the higher cutoffs to triage patients likely to have unilateral PA for further tests and possible adrenalectomy, while using the lower cutoffs to identify others for targeted medical therapy.German Clinical Trials Register ID: DRKS00017084.

Effect of mild cortisol cosecretion on body composition and metabolic parameters in patients with primary hyperaldosteronism.

OBJECTIVE: To investigate the effects of simultaneous cortisol cosecretion (CCS) on body composition in computed tomography (CT)-imaging and metabolic parameters in patients with primary aldosteronism (PA) with the objective of facilitating early detection. DESIGN: Retrospective cohort study. PATIENTS: Forty-seven patients with PA and CCS confirmed by 1-mg dexamethasone suppression test (DST) with a cutoff of ≥1.8 µg/dL were compared with PA patients with excluded CCS (non-CCS, n = 47) matched by age and sex. METHODS: Segmentation of the fat compartments and muscle area at the third lumbar region was performed on non-contrast-enhanced CT images with dedicated segmentation software. Additionally, liver, spleen, pancreas and muscle attenuation were compared between the two groups. RESULTS: Mean cortisol after DST was 1.2 µg/dL (33.1 nmol/L) in the non-CCS group and 3.2 µg/dL (88.3 nmol/L) in the CCS group with mild autonomous cortisol excess (MACE). No difference in total, visceral and subcutaneous fat volumes was observed between the CCS and non-CCS group (p = .7, .6 and .8, respectively). However, a multivariable regression analysis revealed a significant correlation between total serum cholesterol and results of serum cortisol after 1-mg DST (p = .026). Classification of the patients based on visible lesion on CT and PA-lateralization via adrenal venous sampling also did not show any significant differences in body composition. CONCLUSION: MACE in PA patients does not translate into body composition changes on CT-imaging. Therefore, early detection of concurrent CCS in PA is currently only attainable through biochemical tests. Further investigation of the long-term clinical adverse effects of MACE in PA is necessary.

Endocrine Disruptors: Focus on the Adrenal Cortex.

Endocrine-disrupting chemicals (EDCs) are exogenous substances known to interfere with endocrine homeostasis and promote adverse health outcomes. Their impact on the adrenal cortex, corticosteroids and their physiological role in the organism has not yet been sufficiently elucidated. In this review, we collect experimental and epidemiological evidence on adrenal disruption by relevant endocrine disruptors. In vitro data suggest significant alterations of gene expression, cell signalling, steroid production, steroid distribution, and action. Additionally, morphological studies revealed disturbances in tissue organization and development, local inflammation, and zone-specific hyperplasia. Finally, endocrine circuits, such as the hypothalamic-pituitary-adrenal axis, might be affected by EDCs. Many questions regarding the detection of steroidogenesis disruption and the effects of combined toxicity remain unanswered. Not only due to the diverse mode of action of adrenal steroids and their implication in many common diseases, there is no doubt that further research on endocrine disruption of the adrenocortical system is needed.

A novel LC-MS/MS-based assay for the simultaneous quantification of aldosterone-related steroids in human urine.

OBJECTIVES: Primary aldosteronism is the most common cause of endocrine hypertension and is associated with significant cardiovascular morbidities. The diagnostic workup depends on determinations of plasma aldosterone and renin which are highly variable and associated with false-positive and false-negative results. Quantification of aldosterone in 24 h urine may provide more reliable results, but the methodology is not well established. We aimed to establish an assay for urinary aldosterone and related steroids with suitability for clinical routine implementation. METHODS: Here, we report on the development and validation of a quantitative LC-MS/MS method for six urinary steroids: aldosterone, cortisol, 18-hydroxycorticosterone, 18-hydroxycortisol, 18-oxocortisol, tetrahydroaldosterone. After enzymatic deconjugation, total steroids were extracted using SepPak tC18 plates and quantified in positive electrospray ionization mode on a QTRAP 6500+ mass spectrometer. RESULTS: Excellent linearity was demonstrated with R2>0.998 for all analytes. Extraction recoveries were 89.8-98.4 % and intra- and inter-day coefficients of variations were <6.4 and <9.0 %, establishing superb precision. Patients with primary aldosteronism (n=10) had higher mean 24 h excretions of aldosterone-related metabolites than normotensive volunteers (n=20): 3.91 (95 % CI 2.27-5.55) vs. 1.92 (1.16-2.68) µmol/mol for aldosterone/creatinine, 2.57 (1.49-3.66) vs. 0.79 (0.48-1.10) µmol/mol for 18-hydroxycorticosterone/creatinine, 37.4 (13.59-61.2) vs. 11.61 (10.24-12.98) µmol/mol for 18-hydroxycortisol/creatinine, 1.56 (0.34-2.78) vs. 0.13 (0.09-0.17) µmol/mol for 18-oxocortisol/creatinine, and 21.5 (13.4-29.6) vs. 7.21 (4.88-9.54) µmol/mol for tetrahydroaldosterone/creatinine. CONCLUSIONS: The reported assay is robust and suitable for routine clinical use. First results in patient samples, though promising, require clinical validation in a larger sample set.

International multicenter survey on screening and confirmatory testing in primary aldosteronism.

OBJECTIVE: Primary aldosteronism (PA) is one of the most frequent causes of secondary hypertension. Although clinical practice guidelines recommend a diagnostic process, details of the steps remain incompletely standardized. DESIGN: In the present SCOT-PA survey, we have investigated the diversity of approaches utilized for each diagnostic step in different expert centers through a survey using Google questionnaires. A total of 33 centers from 3 continents participated. RESULTS: We demonstrated a prominent diversity in the conditions of blood sampling, assay methods for aldosterone and renin, and the methods and diagnostic cutoff for screening and confirmatory tests. The most standard measures were modification of antihypertensive medication and sitting posture for blood sampling, measurement of plasma aldosterone concentration (PAC) and active renin concentration by chemiluminescence enzyme immunoassay, a combination of aldosterone-to-renin ratio with PAC as an index for screening, and saline infusion test in a seated position for confirmatory testing. The cutoff values for screening and confirmatory testing showed significant variation among centers. CONCLUSIONS: Diversity of the diagnostic steps may lead to an inconsistent diagnosis of PA among centers and limit comparison of evidence for PA between different centers. We expect the impact of this diversity to be most prominent in patients with mild PA. The survey raises 2 issues: the need for standardization of the diagnostic process and revisiting the concept of mild PA. Further standardization of the diagnostic process/criteria will improve the quality of evidence and management of patients with PA.

[Endocrine Disrupting Chemicals]. / Endokrine Disruptoren.

Endocrine disrupting chemicals (EDCs) are universally occurring substances with the potential to interrupt the hormonal system, although the definition of EDCs is not yet standardized. Similar to hormones, EDCs are potentially able to act at very low concentrations, which might be considered save from a toxicological viewpoint. Research over the past years showed that EDCs, even in low doses, might have a relevant impact on human health and the environment as well.The increase of disease burden and disability induced by EDCs causes substantial costs for society. Thus, besides the implications on personal and global health, EDCs affect the economy as well and pose a universal threat to society and environment. Many of the potentially hazardous substances are still inadequately examined and regulated.In this review, we give a brief summary on the previous efforts to classify EDCs and provide a short summary of the current knowledge.

Posttraumatic learning deficits correlate with initial trauma severity and chronic cellular reactions after closed head injury in male mice.

Traumatic brain injury (TBI) is often associated with sustained attention and memory deficits. As persisting neuroinflammation and neurodegeneration may contribute to posttraumatic psychomotor dysfunction, we studied the relationship of brain cellular reactions three months after a weight-drop closed head injury in male mice with posttraumatic learning and memory using automated home-cage monitoring of socially housed mice in IntelliCages as well as tests for locomotor activity, anxiety and forepaw fine motor skills. One month after TBI, deficits in place learning and cognitive flexibility in reverse learning were clearly detectable in IntelliCages and these memory deficits correlated with the initial trauma severity on the functional neuroscore. While sucrose preference or its extinction were not influenced by TBI, traumatized mice performed significantly worse in a complex episodic memory learning task. In consecutive locomotor and forepaw skilled use tests, posttraumatic hyperactivity and impairment of contralateral paw use were evident. Analysis of cellular reactions to TBI three months after injury in selected defined regions of interest in the immediate lesion, ipsi- and contralateral frontoparietal cortex and hippocampus revealed a persistent microgliosis and astrogliosis which were accompanied by iron-containing macrophages and myelin degradation in the lesion area as well as with axonal damage in the neighboring cortical regions. Microglial and astroglial reactions in cortex showed a positive correlation with the initial trauma severity and a negative correlation with the spatial and episodic memory indicating a role of brain inflammatory reactions in posttraumatic memory deficits.

Targeted volumetric single-molecule localization microscopy of defined presynaptic structures in brain sections.

Revealing the molecular organization of anatomically precisely defined brain regions is necessary for refined understanding of synaptic plasticity. Although three-dimensional (3D) single-molecule localization microscopy can provide the required resolution, imaging more than a few micrometers deep into tissue remains challenging. To quantify presynaptic active zones (AZ) of entire, large, conditional detonator hippocampal mossy fiber (MF) boutons with diameters as large as 10 µm, we developed a method for targeted volumetric direct stochastic optical reconstruction microscopy (dSTORM). An optimized protocol for fast repeated axial scanning and efficient sequential labeling of the AZ scaffold Bassoon and membrane bound GFP with Alexa Fluor 647 enabled 3D-dSTORM imaging of 25 µm thick mouse brain sections and assignment of AZs to specific neuronal substructures. Quantitative data analysis revealed large differences in Bassoon cluster size and density for distinct hippocampal regions with largest clusters in MF boutons.