Holger S. Willenberg

Mass Spectrometry–Based Adrenal and Peripheral Venous Steroid Profiling for Subtyping Primary Aldosteronism

BACKGROUNDnDifferentiating patients with primary aldosteronism caused by aldosterone-producing adenomas (APAs) from those with bilateral adrenal hyperplasia (BAH), which is essential for choice of therapeutic intervention, relies on adrenal venous sampling (AVS)-based measurements of aldosterone and cortisol. We assessed the utility of LC-MS/MS-based steroid profiling to stratify patients with primary aldosteronism.nnnMETHODSnFifteen adrenal steroids were measured by LC-MS/MS in peripheral and adrenal venous plasma from AVS studies for 216 patients with primary aldosteronism at 3 tertiary referral centers. Ninety patients were diagnosed with BAH and 126 with APAs on the basis of immunoassay-derived adrenal venous aldosterone lateralization ratios.nnnRESULTSnAmong 119 patients confirmed to have APAs at follow-up, LC-MS/MS-derived lateralization ratios of aldosterone normalized to cortisol, dehydroepiandrosterone, and androstenedione were all higher (P < 0.0001) than immunoassay-derived ratios. The hybrid steroids, 18-oxocortisol and 18-hydroxycortisol, also showed lateralized secretion in 76% and 35% of patients with APAs. Adrenal venous concentrations of glucocorticoids and androgens were bilaterally higher in patients with BAH than in those with APAs. Consequently, peripheral plasma concentrations of 18-oxocortisol were 8.5-fold higher, whereas concentrations of cortisol, corticosterone, and dehydroepiandrosterone were lower in patients with APAs than in those with BAH. Correct classification of 80% of cases of APAs vs BAH was thereby possible by use of a combination of steroids in peripheral plasma.nnnCONCLUSIONSnLC-MS/MS-based steroid profiling during AVS achieves higher aldosterone lateralization ratios in patients with APAs than immunoassay. LC-MS/MS also enables multiple measures for discriminating unilateral from bilateral aldosterone excess, with potential use of peripheral plasma for subtype classification.

PRKACA mutations in cortisol-producing adenomas and adrenal hyperplasia - a single-center study of 60 cases

OBJECTIVEnCortisol excess due to adrenal adenomas or hyperplasia causes Cushings syndrome. Recent genetic studies have identified a somatic PRKACA(L206R) mutation as a cause of cortisol-producing adenomas. We aimed to compare the clinical features of PRKACA-mutant lesions with those of CTNNB1 mutations, and to search for similar mutations in unilateral hyperplasia or tumors co-secreting aldosterone.nnnDESIGN, PATIENTS, AND METHODSnIn this study, 60 patients with cortisol excess who had adrenalectomies at our institution between 1992 and 2013 were assessed, and somatic mutations were determined by Sanger sequencing. A total of 36 patients had overt Cushings syndrome, the remainder were subclinical: 59 cases were adenomas (three bilateral) and one was classified as hyperplasia. Four tumors had proven co-secretion of aldosterone.nnnRESULTSnAmong cortisol-secreting unilateral lesions without evidence of co-secretion (n=52), we identified somatic mutations in PRKACA (L206R) in 23.1%, CTNNB1 (S45P, S45F) in 23.1%, GNAS (R201C) in 5.8%, and CTNNB1+GNAS (S45P, R201H) in 1.9%. PRKACA and GNAS mutations were mutually exclusive. Of the co-secreting tumors, two (50%) had mutations in KCNJ5 (G151R and L168R). The hyperplastic gland showed a PRKACA(L206R) mutation, while patients with bilateral adenomas did not have known somatic mutations. PRKACA-mutant lesions were associated with younger age, overt Cushings syndrome, and higher cortisol levels vs non-PRKACA-mutant or CTNNB1-mutant lesions. CTNNB1 mutations were more significantly associated with right than left lesions.nnnCONCLUSIONSnPRKACA(L206R) is present not only in adenomas, but also in unilateral hyperplasia and is associated with more severe autonomous cortisol secretion. Bilateral adenomas may be caused by yet-unknown germline mutations.

Role of the novel mTOR inhibitor RAD001 (everolimus) in anaplastic thyroid cancer.

Activation of the phosphatidylinositol-3-kinase (PI3K) signaling cascade is increasingly recognized as a common feature of thyroid follicular neoplasms. Among the PI3K downstream effectors, the main kinase, directly responsible for the increased cell growth and proliferation, is called mammalian target of rapamycin (mTOR). This central kinase might be directly inhibited via rapamycin and its derivatives. The aim of the present study was to examine whether RAD001 (everolimus) can selectively suppress the proliferation of different anaplastic thyroid cancer (ATC) cells. Five different human ATC cell lines were exposed to different concentrations of RAD001. Importantly, we found a dose-dependent growth inhibition in two ATC cell lines at concentrations of 43.5 and 94.5 nM although not as intensive as within the RAD001 responding K562cell line. The other cell lines revealed a GI (50) between 168 to 234 nM. In parallel, quantitative PCR of PCNA displayed a reduced expression of PCNA within the responding cell lines, respectively. In summary, we found a good responding effect in a part of ATC cell lines, which may have a clinical impact.

The Effects of the Endothelium on Adrenal Steroidogenesis and Growth are Mainly Mediated by Proteins Other than Endothelin-1

The endothelium releases factors stimulating the adrenal cortex. It is also known that endothelin-1 (ET-1) promotes generation of cortisol and aldosterone, and proliferation of adrenocortical cells. The aim of the study was to find out whether the effect of the endothelium on adrenocortical cells is dominated by the action of ET-1. The effects of endothelial cell-conditioned medium (ECCM), obtained during growth of human umbilical cord vein endothelial cells, on aldosterone and cortisol release by cells of the adrenocortical cancer cell-line NCI-H295R and the promoter activity of steroidogenic acute-regulatory protein (StAR) were studied. The effect of ECCM on proliferation of human primary normal adrenocortical and NCI-H295R cells was also investigated. Concentration-dependent increases in cortisol release that reached 192.7 ± 62.8 in percent of basal secretion, in aldosterone release that reached 188.2 ± 52.3 in percent of basal secretion, and in proliferation after stimulation with ECCM at concentrations of 10-50% were found. ECCM significantly activated the StAR promoter 3-fold in NCI-H295R cells if the ECCM was not pretreated with pronase. These effects of the endothelium were not reversed after co-incubation with endothelin receptor antagonists and could not be mimicked by incubation with endothelin-1. In conclusion, the cultured endothelial cells secrete a protein that stimulates steroidogenesis in adrenal cells and their growth. It was also shown that the ET-1 does not mediate the effect of ECCM on the NCI-H295R cell line.

Reproducibility of Elecsys® Anti-TSHR Test Results in a Lot-to-Lot Comparison

Most recently, a new rapid and fully-automated TSH receptor autoantibody (TRAb) assay has been established. This assay system uses the M22 human monoclonal antibody for competing against the patients TSH receptor autoantibodies (TRAb) to be detected. The aim of our present study was to compare the reproducibility of TRAb values based on measurements with different TSH receptor preparations in a lot-to-lot comparison. For TRAb values > 2 IU/l the relative differences ranged from -9.0 to +10.0%. The mean difference was 0.28 +/- 8%. For TRAb values around the cutoff for positivity (1.75 IU/l) a higher range of relative differences from -20 up to +15% was obtained. The overall mean of differences was -0.8+/-14%. The data clearly demonstrate that the automated TRAb assay has a high stability in regard to TSH receptor preparations.

How to Escape from Primary Aldosteronism? News and Views on an Adrenal Disorder of Salt Retention

The last years have seen substantial progress in primary aldosteronism (PA), which is the most common cause of secondary hypertension. Many programs have been established around the world to meet the needs in healthcare and the management of patients with PA according to published guidelines and clinical protocols. Systematic analysis of emerging data and meticulous scientific work have informed us on the molecular basis of the disease and helped to characterize hereditary forms of PA. Techniques have been developed to better diagnose PA and to establish genotype-phenotype relationships and their impact on hypertension. Studies have been undertaken to stratify patients for risk factors and to ensure quality of best medical treatment. This review focuses on some clinically relevant problems in characterizing autonomous aldosterone secretion and discusses testing and management strategies. Besides, this review puts the emphasis on some colorful studies not to pale soon beside an ever evolving painting background.

Griseofulvin inhibits the growth of adrenocortical cancer cells in vitro.

Supernumerary centrosomes and aneuploidy are associated with a malignant phenotype of tumor cells. Centrosomal clustering is a mechanism used by cancer cells with supernumerary centrosomes to solve the threatening problem of multipolar spindles. Griseofulvin is an antifungal substance that interferes with the microtubule apparatus and inhibits centrosomal clustering. It has also been demonstrated that griseofulvin inhibits the growth of tumor cells in vitro and in vivo. However, it is not yet known whether treatment with griseofulvin inhibits growth of adrenocortical tumor cells. We studied the viability and antiproliferative effects of griseofulvin on cultured NCI-H295R adrenocortical carcinoma cells using Wst-1-, BrdUrd-, and [³H]-thymidine assays. For the detection of apoptosis we used a caspase 3/7 cleavage assay and light microscopy techniques. We observed that incubation with griseofulvin for 24-48 h leads to a decrease in the viability and proliferation of NCI-H295R cells in a dose-dependent manner. Significant effects could be observed after incubation with griseofulvin as measured by Wst-1-, BrdUrd-, and [³H]dT- uptake assays. Apoptosis of NCI-H295R cells was increased in a dose-dependent manner up to 4.5-fold after incubation with griseofulvin 40 μM for 24 h as shown by caspase 3/7 cleavage assay and light microscopy. With regard to new treatment strategies for adrenocortical cancer, griseofulvin, and possibly other agents, which interfere with the microtubule apparatus and inhibit centrosomal clustering, may turn out to be interesting targets for further research.

Biomechanics of the osteoporotic spine, pain, and principles of training

IntroductionA fracture is a clinical manifestation of osteoporosis and is one of the main causes of functional limitations and chronic pain in patients with osteoporosis. Muscle and coordination training are recommended to the patients as general measures. We inquired whether sling training is better than traditional physiotherapy in relieving pain and improving abilities of daily living.MethodsFifty patients with osteoporosis were divided into two groups. Group A performed conventional physiotherapy, while Group B performed sling training exercises. Data were collected before and after the intervention and after 3xa0months. The registered parameters were stamina, posture, and pain. Posture, torques, and the associated strength of spinal muscles were studied in a biomechanical model in order to estimate the forces acting on the spine. Furthermore, the factors that exerted a positive impact on the success of therapy were registered.ResultsForty-four patients (88%) completed the study. Positive effects of the training were noted in both groups, but significantly better effects were observed in the group that performed sling training. A reduction of pain independent of the number of fractures, significantly reduced torques, and reduced muscle strength were registered.ConclusionsSpecific training programs helped to increase muscle strength and straightening the back thereby reducing the force needed on a permanent basis and decreasing torque in the spine. Sling training was more effective in that than traditional physiotherapy.

Confirmatory Testing for Primary Aldosteronism

To minimize the influence of medication, potassium, angiotensin 2, and corticotropin, because mechanisms of aldosterone escape have been described, and to increase specificity in the diagnostic process, confirmatory testing is necessary in cases suspected to have primary aldosteronism.

HLA-A2 phenotype may be protective against Graves' disease but not against Hashimoto's thyroiditis in Caucasians.

Graves disease (GD) and Hashimotos thyroiditis (HT) are the most common autoimmune thyroid diseases (AITDs) affecting up to 5% of the general population. In Caucasians HT has a prevalence of up to 4.60% and GD a prevalence of 1-2%. The aim of this study was to investigate the association between HLA-A2 and the AITDs GD and HT among Caucasians. HLA alleles of 33 patients with GD and 75 patients with HT were determined by serological typing. The frequency of HLA A2 was significantly reduced in GD (p=0.033) but not in HT (p=n.s.) as compared to control samples. In individuals positive for HLA-A2 odds ratio for protection from GD was found to be 2.8. This study supports the hypothesis that genetic predisposition to GD is not restricted to MHC class II molecules. The significant negative association between HLA A2 and GD supports the hypothesis that MHC class I genes may be relevant for the protection from GD. In contrast the nonsignificant results for HT indicate that this association may not apply to AITDs in general.