Comparison and commutability study between standardized liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) and chemiluminescent enzyme immunoassay for aldosterone measurement in blood.

A commutability confirmation test for the blood aldosterone measurement was performed on liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) as a designated comparison method (DCM) and four chemiluminescent enzyme immunoassay (CLEIA) measurement procedures based on metrological traceability. A conventional radioimmunoassay (RIA) and two measurement procedures of CLEIA which obtains RIA equivalent values were also compared. The relationship between the DCM value and the CLEIA value with respect to 120 pg/mL of the RIA value, which is the screening criterion of primary aldosteronism (PA) was clarified. For the correlation test, 75 samples of patient serum and plasma were used. Regression analysis revealed that the standardized LC-MS/MS and four CLEIA measurement procedures were in good agreement. This is the effect of measurement specificity and calibration using by certified reference material (CRM). The median of the LC-MS/MS corresponding to 120 pg/mL of RIA was 48.5 pg/mL. In the mean of standardized four CLEIA values corresponding to the 48.5 pg/mL of LC-MS/MS value was 47.51 pg/mL and the standard deviation (SD) was 2.93 pg/mL. However, the correlation between the RIA value and the RIA equivalent of the two measurement procedures by CLEIA differed depending on the measurement procedure. This is due to the influence of RIA measurement performance. Standardized CLEIA measurements are suitable for routine measurement procedure. When converting the LC-MS/MS equivalent value by the standardized CLEIA to the conventional RIA value, it is necessary to use the conversion formula.

Japan Endocrine Society clinical practice guideline for the diagnosis and management of primary aldosteronism 2021.

Primary aldosteronism (PA) is associated with higher cardiovascular morbidity and mortality rates than essential hypertension. The Japan Endocrine Society (JES) has developed an updated guideline for PA, based on the evidence, especially from Japan. We should preferentially screen hypertensive patients with a high prevalence of PA with aldosterone to renin ratio ≥200 and plasma aldosterone concentrations (PAC) ≥60 pg/mL as a cut-off of positive results. While we should confirm excess aldosterone secretion by one positive confirmatory test, we could bypass patients with typical PA findings. Since PAC became lower due to a change in assay methods from radioimmunoassay to chemiluminescent enzyme immunoassay, borderline ranges were set for screening and confirmatory tests and provisionally designated as positive. We recommend individualized medicine for those in the borderline range for the next step. We recommend evaluating cortisol co-secretion in patients with adrenal macroadenomas. Although we recommend adrenal venous sampling for lateralization before adrenalectomy, we should carefully select patients rather than all patients, and we suggest bypassing in young patients with typical PA findings. A selectivity index ≥5 and a lateralization index >4 after adrenocorticotropic hormone stimulation defines successful catheterization and unilateral subtype diagnosis. We recommend adrenalectomy for unilateral PA and mineralocorticoid receptor antagonists for bilateral PA. Systematic as well as individualized clinical practice is always warranted. This JES guideline 2021 provides updated rational evidence and recommendations for the clinical practice of PA, leading to improved quality of the clinical practice of hypertension.

Diagnosis and treatment of autoimmune and IgG4-related hypophysitis: clinical guidelines of the Japan Endocrine Society.

Hypophysitis, which is often accompanied by pituitary dysfunction, is classified into several subtypes based on the cause, histology, and the location of inflammation in the pituitary gland. A definitive diagnosis requires pituitary biopsy, which is invasive, and the process is limited to specialized clinical settings. In this opinion paper, we review the literature associated with hypophysitis, and provide the guidelines of the Japan Endocrine Society for the diagnosis and treatment of autoimmune and IgG4-related hypophysitis.

Abnormal thyroid hormone response to TRH in a case of macro-TSH and the cut-off value for screening cases of inappropriate TSH elevation.

A 74-year-old asymptomatic Japanese man with suspected thyroid dysfunction was referred to our hospital. He had an elevated TSH (53.8 mIU/L; reference interval: 0.5-5.0) despite a free T4 (FT4) level (1.4 ng/dL; reference interval: 0.9-1.6). Further analysis revealed macro-TSH. A notable finding was that a 500-µg TRH stimulation test revealed a blunted free T3 (FT3) response despite a prolonged TSH response. Macro-TSH typically presents with inappropriately marked elevation of serum TSH levels compared with other thyroid hormones, as exhibited in our case. However, the level of TSH elevation that might differentiate macro-TSH from subclinical hypothyroidism is poorly known. We retrospectively analyzed 8,183 concurrent measurements of TSH and FT4 in individuals previously examined in our hospital to define the cut-off value for screening cases of inappropriate TSH elevation. FT4 values were rounded off to one decimal place, and the 97.5th percentile of TSH against each FT4 value was calculated. The data of our patient and that of 30 cases of macro-TSH extracted from the English literature were then assessed. When the approximate curve obtained from the 97.5th percentile of TSH values was defined as the cut-off value [Log10TSH = 0.700 + 1.549/{1 + (FT4/0.844)6.854}], 25 of the 31 (80.6%) macro-TSH cases were identified. In conclusion, we report for the first time a case of macro-TSH demonstrating an abnormal FT3 response to TRH. A cut-off value of TSH adjusted to the FT4 level may be a good method of screening for inappropriate TSH elevation (or inappropriate hyperthyrotropinemia) including those caused by macro-TSH.

Presence of aberrant adrenocorticotropic hormone precursors in two cases of McCune-Albright syndrome.

McCune-Albright syndrome (MAS) is a rare disorder. MAS is classically defined by the occurrence of fibrous dysplasia, café-au-lait skin macules, and precocious puberty. In addition to precocious puberty, other hyperfunctioning endocrinopathies may occur. We evaluated hypothalamic-pituitary-adrenal function in two cases of typical MAS associated with fibrous dysplasia and growth hormone excess. Pituitary adenoma or hyperplasia was not detected by magnetic resonance imaging. Hormonal data showed normal or low cortisol levels, despite high ACTH levels in the blood. A high ratio of circulating ACTH to cortisol was found in the two cases. Insulin tolerance and CRH tests showed hyper-responses of ACTH and an insufficient increase in cortisol levels. No involvement of 11ß-HSD1 by GH excess was suggested because basal levels of ACTH and cortisol showed no changes, even after therapy for acromegaly by somatostatin analogues. Patients with Cushing's disease cases of pituitary macroadenoma can have high circulating ACTH precursor levels, and elevated ACTH precursors have been observed in ectopic ACTH syndrome. Autonomous cortisol excess was excluded by the level of midnight cortisol and the level of cortisol after a low-dose dexamethasone suppression test in the two cases. Finally, the gel filtration profiles of immunoreactive ACTH contents showed the presence of aberrant ACTH precursors. To the best of our knowledge, there have been no reports of MAS associated with aberrant ACTH precursors. Our findings in these cases emphasize that attention should be to secretion of inactive ACTH precursors in MAS.

Influence of thyroid dysfunction on brain natriuretic peptide level in health examination participants.

The tissue-specific circulating markers of thyroid hormone action on cardiac function have not been established. Although the relationship between thyroid function and plasma brain natriuretic peptide (BNP) levels has been evaluated in patients with thyroid disorders, the relationship between these parameters in the general population has not been yet studied. We conducted retrospective cohort study by health examination with concurrent measurements of TSH, free T4, body mass index, systolic blood pressure, hemoglobin, and estimated glomerular filtration rate from participants who visited the Department of Health Checkup, Enshu Hospital between July 2008 and March 2017. After participants with abnormal electrocardiogram and/or any history of cardiac disease were excluded, 2,807 individuals were subjected. Multivariate analyses demonstrated that, when compared to euthyroidism (n = 2,629), the increase in BNP levels was significant in overt thyrotoxicosis (n = 21) but not in subclinical thyrotoxicosis (n = 53) or subclinical hypothyroidism (n = 97). Interestingly, the standardized partial regression coefficient was the smallest for thyroid function category (overt thyrotoxicosis compared to euthyroidisim; ß = 0.048, p = 0.006) among the independent variables including age, body mass index, systolic blood pressure, and hemoglobin. In longitudinal comparison, we identified 986 participants who had sequential data on the measurements and were stable as euthyroidism and subclinical hypothyroidism. Their annual percent change in BNP demonstrated no significant differences. In conclusion, a direct stimulatory effect of thyroid hormone on the secretion (or production) of BNP was confirmed even in a large number of health examination participants.

Falsely elevated plasma ACTH levels measured by the Elecsys assay related to heterophilic antibody in a case of secondary adrenocortical insufficiency.

A 49-year-old woman with membranous nephropathy was referred to our hospital during the tapering of oral prednisolone, because of suspicion of primary adrenal insufficiency based on a plasma ACTH level of 399.1 pg/mL in the Elecsys assay and a serum cortisol level of 3.1 µg/dL. A rapid ACTH stimulation test revealed a suboptimal response, whereas a prolonged ACTH simulation test showed a sufficient increase in her urinary free cortisol. Also, big ACTH was not detected by gel exclusion chromatography. Therefore, we speculated that ACTH levels were falsely elevated due to some interference substances. Pretreatment of her plasma with either polyethylene glycol precipitation or a heterophilic blocking tube substantially reduced her ACTH values. When either the Immulite ACTH II or the TOSOH II ACTH was tried instead of the Elecsys ACTH, her plasma ACTH values turned out to be lower and appropriate for her clinical status. These results indicated that heterophilic antibodies interfered only with the Elecsys ACTH assay presumably by bridging the capture and tracer antibodies. To our knowledge, this is the first case in which the Elecsys ACTH assay yielded falsely elevated results. Regardless of the measurement system used, if there is a discordance between assay results and clinical findings, it should be considered to adopt additional procedures and/or another assay.

Successful reduction of ACTH secretion in a case of intractable Cushing's disease with pituitary Crooke's cell adenoma by combined modality therapy including temozolomide.

Crooke's cell adenoma (CCA) is an aggressive subtype of corticotroph adenoma; however, CCA is associated with a high incidence of low expression of methyl guanine methyl transferase (MGMT), suggesting that temozolomide (TMZ) treatment might be effective for this tumor type. The case of a 56-year-old woman with Cushing's disease caused by a pituitary CCA is presented. At the age of 38 years, the patient presented to our hospital with polyuria and a visual field defect. MRI and laboratory studies showed a 4.5-cm-diameter pituitary tumor with plasma adrenocorticotropic hormone (ACTH) and serum cortisol levels of more than 500 pg/mL and 40 µg/dL, respectively. At 39 years of age, the patient underwent a craniotomy, and her plasma ACTH and cortisol levels decreased to less than 200 pg/mL and 10 µg/dL, respectively; however, these hormone levels increased gradually to 3,940 pg/mL and 70 µg/dL, respectively, by the time the patient was 56 years old. Histopathological re-examination of the previously resected specimen showed that the pituitary tumor was MGMT-negative CCA. TMZ treatment after the second operation decreased the plasma ACTH levels from 600-800 pg/mL to 70-300 pg/mL. No signs of recurrence were observed in the seven years following these treatments with added prophylactic radiation therapy. These clinical findings suggest that TMZ treatment to patients with CCA accompanied with elevated ACTH may be good indication to induce lowering ACTH levels and tumor shrinkage.

New diagnostic criteria of adrenal subclinical Cushing's syndrome: opinion from the Japan Endocrine Society.

New diagnostic criteria and the treatment policy for adrenal subclinical Cushing's syndrome (SCS) are proposed on behalf of the Japan Endocrine Society. The Japanese version has been published, and the essential contents are presented in this English-language version. The current diagnostic criteria for SCS have elicited two main problems: (i) the relatively low reliability of a low range of serum cortisol essential for the diagnosis by an overnight 1-mg dexamethasone suppression test (DST); (ii) different cutoff values for serum cortisol after a 1-mg DST compared with those of other countries. Thus, new criteria are needed. In the new criteria, three hierarchical cortisol cutoff values, 5.0, 3.0 and 1.8 µg/dL, after a 1-mg DST are presented. Serum cortisol ≥5 µg/dL after a 1-mg DST alone is considered sufficient to judge autonomous cortisol secretion for the diagnosis of SCS, and the current criterion based on serum cortisol ≥3 µg/dL after a 1-mg DST can continue to be used. Clinical evidence suggests that serum cortisol ≥1.8-2.9 µg/dL after a 1-mg DST is not always normal, so cases who meet the cutoff value as well as a basal adrenocorticotropic hormone (ACTH) level <10 pg/mL (or poor ACTH response to corticotropin-releasing hormone (CRH)) and nocturnal serum cortisol ≥5 µg/dL are proposed to have SCS. We suggest surgery if cases show serum cortisol ≥5 µg/dL after a 1-mg DST (or are disheartened by treatment-resistant problems) or suspicious cases of adrenal cancer according to tumor imaging.

Diagnosis and treatment of adrenal insufficiency including adrenal crisis: a Japan Endocrine Society clinical practice guideline [Opinion].

This clinical practice guideline of the diagnosis and treatment of adrenal insufficiency (AI) including adrenal crisis was produced on behalf of the Japan Endocrine Society. This evidence-based guideline was developed by a committee including all authors, and was reviewed by a subcommittee of the Japan Endocrine Society. The Japanese version has already been published, and the essential points have been summarized in this English language version. We recommend diagnostic tests, including measurement of basal cortisol and ACTH levels in combination with a rapid ACTH (250 µg corticotropin) test, the CRH test, and for particular situations the insulin tolerance test. Cut-off values in basal and peak cortisol levels after the rapid ACTH or CRH tests are proposed based on the assumption that a peak cortisol level ≥18 µg/dL in the insulin tolerance test indicates normal adrenal function. In adult AI patients, 15-25 mg hydrocortisone (HC) in 2-3 daily doses, depending on adrenal reserve and body weight, is a basic replacement regime for AI. In special situations such as sickness, operations, pregnancy and drug interactions, cautious HC dosing or the correct choice of glucocorticoids is necessary. From long-term treatment, optimal diurnal rhythm and concentration of serum cortisol are important for the prevention of cardiovascular disease and osteoporosis. In maintenance therapy during the growth period of patients with 21-hydroxylase deficiency, proper doses of HC should be used, and long-acting glucocorticoids should not be used. Education and carrying an emergency card are essential for the prevention and rapid treatment of adrenal crisis.

Calibration and evaluation of routine methods by serum certified reference material for aldosterone measurement in blood.

We attempted to study the standardization of aldosterone measurement in blood. The serum certified reference material (serum CRM) was established by spiking healthy human serum with pure aldosterone. ID-LC/MS/MS as a reference measurement procedure was performed by using the serum CRM. LC-MS/MS as a comparison method (CM) was routinely used for clinical samples, and the values with and without calibration by the serum CRM were compared. The serum CRM demonstrated similar reactivity with peripheral blood plasma as clinical samples in routine methods (RM) of RIA, ELISA, and CLEIA. In comparison between RM and CM, the results in regression analysis indicated that the range of the correlation coefficient (r) was 0.913 - 0.991, the range of y intercept was 0.9 - 67.3 pg/mL and the range of slope was 0.869 - 1.174. The values by RM in 100 - 150 pg/mL for the diagnostic level, had a significant calibration effect, and the relative difference between calibrated value in RM and result by CM was within ±20%. Furthermore, the calibrated value using the serum CRM was 10,187 pg/mL, which corresponds to measured value of 14,000 pg/mL using RIA for the adrenal venous sampling. Measured values between plasma and serum as a sample for the aldosterone measurement from clinical samples showed no significant differences. In conclusion, we succeeded to prepare the certified reference material of aldosterone for RM. Then, we can accurately calculate corrected values by using our equation for four RMs of determination of aldosterone.

Aphidicolin inhibits cell proliferation via the p53-GADD45ß pathway in AtT-20 cells.

Cushing's disease is primarily caused by pituitary corticotroph adenomas, which autonomically secrete adrenocorticotropic hormone (ACTH). ACTH production may be associated with tumor cell proliferation; however, the effects of cell cycle progression on ACTH production and cell proliferation are little known in corticotroph tumor cells. A DNA polymerase inhibitor, aphidicolin, arrests cells at the entrance to the S phase and blocks the cell cycle; aphidicolin also induces apoptosis in tumor cells. In the present study, we determined ACTH production and cell proliferation of AtT-20 corticotroph tumor cells following treatment with aphidicolin. Aphidicolin decreased proopiomelanocortin mRNA levels in AtT-20 cells and the levels of ACTH in the culture medium of these cells. Aphidicolin also decreased cell proliferation and induced apoptosis in AtT-20 cells. Fluorescence-activated cell sorting analyses revealed that this agent increased the percentage of G0/G1 phase cells, and decreased S phase cells. Aphidicolin decreased the phosphorylation of cyclic adenosine monophosphate response element-binding protein and Akt. Aphidicolin increased the levels of tumor protein 27 (p27) and 53 (p53), while it decreased cyclin E levels. Aphidicolin also increased the mRNA levels of the stress response gene growth arrest and DNA damage-inducible 45ß (GADD45ß), a putative downstream target of p53. The p53 knockdown increased GADD45ß mRNA levels. The GADD45ß knockdown inhibited the decreases in cell proliferation. Thus, aphidicolin inhibits cell proliferation via the p53-GADD45ß pathway in AtT-20 cells.

Pathophysiology and treatment of subclinical Cushing's disease and pituitary silent corticotroph adenomas [Review].

Pituitary adrenocorticotropic hormone (ACTH)-secreting tumor presents with a variety of clinical features. We outlined the features of ACTH release and characteristics of corticotroph adenoma cells. We especially focused on the corticotroph adenomas in patients with no clinical features of Cushing's disease. Subclinical Cushing's disease is defined by ACTH-induced mild hypercortisolism without typical features of Cushing's disease. Silent corticotroph adenomas (SCAs) are defined by normal cortisol secretion and ACTH-immunopositive staining without autonomous ACTH secretion. Clinicians who are not well-informed about the disease may sometimes confuse SCAs (because of their clinically silent nature) with "subclinical Cushing's disease". The recent criteria for diagnosing subclinical Cushing's disease in Japan are presented. Cortisol measurement was recently standardized in Japan, so plasma cortisol cutoff level should be reconsidered for the diagnosis. In patients with uncontrolled diabetes and hypertension despite appropriate treatment, subclinical Cushing's disease may be efficiently detected. Subclinical Cushing's disease may be associated with metabolic change. In subclinical Cushing's disease, mild hypercortisolism due to autonomous secretion of ACTH contributes to metabolic change and treatment of subclinical hypercortisolism can reverse this change.

Laparoscopic simultaneous bilateral adrenalectomy for testosterone-secreting bilateral adrenal tumors.

Laparoscopic adrenalectomy is widely accepted as a safe and minimally-invasive procedure. Although it is a standard procedure for the surgical treatment of adrenal tumors, its simultaneous use with bilateral adrenalectomy is relatively rare. A 21-year-old woman was referred to Hamamatsu University School of Medicine University Hospital complaining of a deepening voice, hirsutism and secondary amenorrhea. Abdominal computed tomography showed bilateral adrenal tumors, and hormonal examinations showed that the tumors secreted excessive testosterone, resulting in virilizing symptoms. Laparoscopic simultaneous bilateral adrenalectomy was carried out. Postoperatively, serum testosterone levels immediately recovered to within the normal range. Menstruation began the month after the operation, and the hirsutism gradually regressed. This is the third reported case of bilateral virilizing adrenal tumors, and the first to be successfully treated with laparoscopic simultaneous bilateral adrenalectomy.

Histopathological analysis of tumor microenvironment in adrenocortical carcinoma: Possible effects of in situ disorganized glucocorticoid production on tumor immunity.

Adrenocortical carcinoma (ACC) patients with glucocorticoid excess have been reported to be associated with decreased tumor-infiltrating immune cells, but the effects of in situ glucocorticoid production on tumor immunity have remained unknown. In addition, ACC was also known to harbor marked intra-tumoral heterogeneity of steroidogenesis or disorganized steroidogenesis. Therefore, in this study, we immune-profiled tumor-infiltrating lymphocytes (TILs) and tumor-associated macrophages (TAMs) and pivotal steroidogenic enzymes of glucocorticoid biosynthesis (CYP17A and CYP11B1) to explore the potential effects of in situ glucocorticoid production and intra-tumoral heterogeneity/disorganized steroidogenesis on tumor immunity of ACC. We also studied the correlations of the status of tumor immunity with that of angiogenesis and tumor grade to further explore the tumor tissue microenvironment of ACC. TILs (CD3, CD4, CD8, and FOXP3), TAMs (CD68 and CD163), key steroidogenic enzymes of glucocorticoid (CYP17A and CYP11B1), angiogenesis (CD31 and vasohibin-1 (VASH-1)), tumor grade (Ki-67 and Weiss score) were immunohistochemically evaluated in 34 ACCs. Increased CYP17A immunoreactivity in the whole tumor area was significantly positively correlated with FOXP3-positive TILs (p = 0.021) and negatively with CD4/CD3 ratio (p = 0.001). Increased CYP11B1 immunoreactivity in the whole tumor area was significantly positively correlated with CD8/CD3 (p = 0.039) and CD163/CD68 ratios (p = 0.006) and negatively with CD4-positive TILs (p = 0.036) and CD4/CD3 ratio (p = 0.001). There were also significant positive correlations between CYP17A and CD8 (r = 0.334, p < 0.001) and FOXP3-positive TILs (r = 0.414, p < 0.001), CD8/CD3 ratio (r = 0.421, p < 0.001), and CD68-positive TAMs (r = 0.298, p < 0.001) in randomly selected areas. Significant positive correlations were also detected between CYP11B1 and CD8/CD3 ratio (r = 0.276, p = 0.001) and negative ones detected between CYP11B1 and CD3- (r = -0.259, p = 0.002) and CD4-positive TILs (r = -0.312, p < 0.001) in those areas above. Increased micro-vessel density (MVD) -VASH-1 was significantly positively correlated with CD68- (p = 0.015) and CD163-positive TAMs (p = 0.009) and CD163/CD68 ratio and the high VASH-1 with CD163-positive TAMs (p = 0.042). Ki-67 labeling index was significantly positively correlated with MAD-VASH-1 (p = 0.006) and VASH-1 (p = 0.006) status. Results of our present study indicated that in situ glucocorticoid production did influence the status of tumor immunity in ACC. In particular, increased levels of CYP17A and CYP11B1, both involved in glucocorticoid producing immunoreactivity played different effects on tumor immunity, i.e., reflecting the involvement of intra-tumoral heterogeneity and disorganized steroidogenesis of ACC, which also did indicate the importance of in situ approaches when analyzing tumor immunity of ACC.

Evaluation of the diagnostic criteria for Cushing's disease in Japan.

Adrenocorticotropic hormone (ACTH)-dependent Cushing's syndrome is caused by an ACTH-producing tumor, as is the case with Cushing's disease and ectopic ACTH syndrome (EAS). Diagnosis and differential diagnosis of Cushing's disease from EAS in ACTH-dependent Cushing's syndrome are thus challenging problems in clinical endocrinology. The diagnostic criteria for Cushing's disease in Japan, established by the working group of the Japan Ministry of Health, Labour and Welfare, were originally reported in 2003 and revised in 2007 and 2010. In addition, criteria for subclinical Cushing's disease were established in Japan in 2010. In this review, we evaluate the usefulness and accuracy of the most recent diagnostic criteria. Previous data suggest that as an initial test of Cushing's syndrome, 0.5 mg dexamethasone is more sensitive than 1 mg in the overnight dexamethasone suppression test (DST). Here, we recommend 0.5 mg plus a plasma cortisol cut-off level of 3 µg/dL as a suitable low-dose overnight DST for screening of all cases of ACTH-dependent Cushing's syndrome in Japan. Recently, standardization of cortisol measurements by the ID-LC/MS/MS method using seven assay kits with standard plasma material containing synthetic hydrocortisone-d4 was carried out in Japan. The resulting relative standard deviation was within 10%. The cut-off value remains valid even after standardization of plasma cortisol measurements. Although the recent diagnostic criteria achieve higher diagnostic specificity, care should be taken since data for Cushing's disease partially overlaps with some cases of EAS. Overall, therefore, this review suggests that the accuracy of each diagnostic test should be considered.

Factors associated with fluorine-18-fluorodeoxyglucose uptake in benign thyroid nodules.

Thyroid nodules that exhibit focal uptake of fluorine-18 ((18)F)-fluorodeoxyglucose (FDG) are relatively frequent. Although the clinical features and associated mechanisms of FDG-avid lesions in both thyroid cancer and cytologically indeterminate nodules have been extensively studied, not much information is available on benign nodules. Therefore, in this retrospective study, the clinical, serological, and sonographic features of 15 benign FDG-avid nodules were compared with those of 17 non-avid lesions. Univariate analysis indicated that the FDG-positive and -negative nodules were similar with regard to age, gender, thyroid stimulating hormone (TSH), anti-thyroglobulin antibodies, tumor size, 4 B-mode sonographic findings (i.e., shape, margin, texture, and echo level), and/or elasticity. The presence of intranodular blood flow and the absence of a cystic component were associated with a greater possibility of positive FDG uptake. Multivariate analysis showed that vascularity was the only independent factor predicting FDG uptake. Across a wide range of tumor types, the extent of FDG uptake is positively correlated with tumor perfusion; this observation is consistent with the results of this study, which shows that FDG uptake in benign thyroid nodules is associated with increased vascularity.

Falsely elevated thyroid hormone levels caused by anti-ruthenium interference in the Elecsys assay resembling the syndrome of inappropriate secretion of thyrotropin.

The syndrome of inappropriate secretion of thyrotropin (SITSH) is defined as the inappropriate non-suppression of serum TSH in the presence of elevated free thyroid hormone; TSH-secreting pituitary adenomas and the syndrome of resistance to thyroid hormone are the main etiologies of SITSH. In addition, erroneous thyroid function testing may result in the diagnosis of this syndrome. A 63-year-old woman was referred because of suspected SITSH. Laboratory tests showed a normal TSH (0.52 µIU/L; normal range: 0.5-5.0) measured by sandwich Elecsys, and elevated FT4 (3.8 ng/dL; normal range: 0.9-1.6) and FT3 (7.6 pg/mL; normal range: 2.3-4.0), determined by competitive Elecsys. To exclude possible assay interference, aliquots of the original samples were retested using a different method (ADVIA Centaur), which showed normal FT4 and FT3 levels. Eight hormone levels, other than thyroid function tests measured by competitive or sandwich Elecsys, were higher or lower than levels determined by an alternative analysis. Subsequent examinations, including gel filtration chromatography, suggested interference by substances against ruthenium, which reduced the excitation of ruthenium, and resulted in erroneous results. The frequency of similar cases, where the FT4 was higher than 3.2 ng/dL, in spite of a non-suppressed TSH, was examined; none of 10 such subjects appeared to have method-specific interference. Here, a patient with anti-ruthenium interference, whose initial thyroid function tests were consistent with SITSH, is presented. This type of interference should be considered when thyroid function is measured using the Elecsys technique, although the frequency of such findings is likely very low.

Neuropeptide W stimulates adrenocorticotrophic hormone release via corticotrophin-releasing factor but not via arginine vasopressin.

Neuropeptide W (NPW) was isolated as an endogenous ligand for NPBWR1, an orphan G protein-coupled receptor localized in the rat brain, including the paraventricular nucleus. It has been reported that central administration of NPW stimulates corticosterone secretion in rats. We hypothesized that NPW activates the hypothalamic-pituitary-adrenal (HPA) axis via corticotrophin-releasing factor (CRF) and/or arginine vasopressin (AVP). NPW at 1 pM to 10 nM did not affect basal or ACTH-induced corticosterone release from dispersed rat adrenocortical cells, or basal and CRF-induced ACTH release from dispersed rat anterior pituitary cells. In conscious and unrestrained male rats, intravenous administration of 2.5 and 25 nmol NPW did not affect plasma ACTH levels. However, intracerebroventricular (icv) administration of 2.5 and 5.0 nmol NPW increased plasma ACTH levels in a dose-dependent manner at 15 min after stimulation (5.0 vs. 2.5 nmol NPW vs. vehicle: 1802 ± 349 vs. 1170 ± 204 vs. 151 ± 28 pg/mL, respectively, mean ± SEM). Pretreatment with astressin, a CRF receptor antagonist, inhibited the increase in plasma ACTH levels induced by icv administration of 2.5 nmol NPW at 15 min (453 ± 176 vs. 1532 ± 343 pg/mL, p<0.05) and at 30 min (564 ± 147 vs. 1214 ± 139 pg/mL, p<0.05) versus pretreatment with vehicle alone. However, pretreatment with [1-(ß-mercapto-ß, ß-cyclopentamethylenepropionic acid), 2-(Ο-methyl)tyrosine]-arg-vasopressin, a V1a/V1b receptor antagonist, did not affect icv NPW-induced ACTH release at any time (p>0.05). In conclusion, we suggest that central NPW activates the HPA axis by activating hypothalamic CRF but not AVP.

Safety and feasibility of radiofrequency ablation using bipolar electrodes for aldosterone-producing adenoma: a multicentric prospective clinical study.

Evaluation of feasibility and safety of percutaneous radiofrequency ablation using bipolar radiofrequency devices in a prospective multicenter cohort of patients with benign aldosterone-producing adenoma. A total of five institutions participated. CT-guided percutaneous RFA was performed for patients diagnosed as APA. The safety of the procedure was evaluated using the Common Terminology Criteria for Adverse Events. During the 84-day follow-up period, serial changes in plasma aldosterone concentration and plasma renin activity were measured. The percentage of patients with normalized hormonal activity after the procedure, was calculated with 95% confidence intervals. Forty patients were enrolled, and two patients were excluded for cerebral hemorrhage and no safe puncture root. In another patients, RFA was tried, but an intraprocedural intercostal arterial injury occurred. Consequently, RFA was completed in thirty-seven patients (20 men, 17 women; mean age, 50.4 ± 10.0 year). The tumor size was 14.8 ± 3.8 mm. The treatment success rate of the ablation was 94.6% (35/37), and a 2nd session was performed in 2.7% (1/37) patients. Grade 4 adverse events were observed in 4 out of 38 sessions (10.5%). The normalization of plasma aldosterone concentration or aldosterone-renin ratio was 86.5% (72.0-94.1: 95% confidence interval) on day 84. Percutaneous CT-guided RFA for APA using a bipolar radiofrequency system was safe and feasible with clinical success rate of 86.5% on day 84.