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Background: An elevation of fractionated plasma or urinary metanephrine (MN) or nor-metanephrine (NMN), collectively called metanephrines (MN and NMN), >4-fold above the upper limit of normal (ULN) is usually considered to be diagnostic for pheochromocytoma (PHEO). There are a greater number of false positive results when the elevations are more modest., Aim: To identify biochemical and radiological features in PHEOs with modest elevations (<4-fold above ULN) of metanephrines., Methodology: We retrospectively reviewed the charts of 112 patients with PHEO (10% extra-adrenal) and 208 patients with a non-PHEO adrenal mass operated from 1997-2011, who had metanephrines measured pre-operatively. We divided PHEO into group 1 (n = 90) with metanephrines ≥4-fold ULN and group 2 (n = 22) with metanephrines <4-fold ULN. The non-PHEO group was designated as group 3., Results: The median (range) tumour size in group 1 and group 2 was 4·8 cm (1·7-22) and 3·0 cm (1·7-5) respectively (P < 0·001). All patients with PHEO in group 2 had a tumour <5 cm in size. The MN fraction was elevated in about 65% of groups 1 and 2; only 2 (1%) patients in group 3 had an elevated urinary MN fraction, and none were associated with an elevated plasma MN fraction. All PHEOs had a pre-contrast attenuation ≥17 Hounsfield Units (HU)., Conclusions: Modest elevations (<4-fold ULN) of the NMN fraction in an adrenal mass >5 cm are almost always falsely positive. Elevations in plasma and urinary MN fraction are less likely to be false positive. The CT pre-contrast attenuation of PHEOs is >10 HU., (© 2014 John Wiley & Sons Ltd.)

Introduction: Urinary metanephrines are widely used in the diagnosis of catecholamine secreting tumours. Over the past two years we have been using the commercial Recipe(®) ClinRep(®) Complete Kit for Metanephrines in Urine coupled with high-performance liquid chromatography and coulometric detection. It was noticed that the internal standards on the patient chromatograms were sporadically raised due to interference., Methods: The interference had identical chromatographic and electrochemical properties to the Recipe(®) internal standard (undisclosed identity). Inspection of the patient names showed it seemingly had a higher frequency and magnitude in patients of Indian origin. The source of the interference was tracked by dietary observation and intervention to curry leaves, a common component of Indian foods., Results: The interference was chromatographically and electrochemically indistinguishable from the internal standard. The mass spectrum of the pentafluoropropionate derivative of the interference matched the Recipe(®) internal standard and was identified as methoxyhydroxybenzylamine by library match., Conclusion: The component co-elutes exactly with internal standard and artifactually decreases the metanephrine and normetanephrine results. It is surprising that it has not been described previously. Patients being assessed for catecholamine secreting tumours should be advised to withdraw from eating Indian foods at least 24 h prior to commencement of urinary collection.

Objective: To document the influences of blood sampling under supine fasting versus seated nonfasting conditions on diagnosis of phaeochromocytomas and paragangliomas (PPGL) using plasma concentrations of normetanephrine, metanephrine and methoxytyramine., Design and Methods: Biochemical testing for PPGL was performed on 762 patients at six centres, two of which complied with requirements for supine sampling after an overnight fast and four of which did not. Phaeochromocytomas and paragangliomas were found in 129 patients (67 noncompliant, 62 compliant) and not in 633 patients (195 noncompliant, 438 compliant)., Results: Plasma concentrations of normetanephrine and methoxytyramine did not differ between compliant and noncompliant sampling conditions in patients with PPGL but were 49-51% higher in patients without PPGL sampled under noncompliant compared with compliant conditions. The 97·5 percentiles of distributions were also higher under noncompliant compared with compliant conditions for normetanephrine (1·29 vs 0·79 nmol/l), metanephrine (0·49 vs 0·41 nmol/l) and methoxytyramine (0·42 vs 0·18 nmol/l). Use of upper cut-offs established from seated nonfasting sampling conditions resulted in substantially decreased diagnostic sensitivity (98% vs 85%). In contrast, use of upper cut-offs established from supine fasting conditions resulted in decreased diagnostic specificity for testing under noncompliant compared with compliant conditions (71% vs 95%)., Conclusions: High diagnostic sensitivity of plasma normetanephrine, metanephrine and methoxytyramine for the detection of PPGL can only be guaranteed using upper cut-offs of reference intervals established with blood sampling under supine fasting conditions. With such cut-offs, sampling under seated nonfasting conditions can lead to a 5·7-fold increase in false-positive results necessitating repeat sampling under supine fasting conditions., (© 2013 John Wiley & Sons Ltd.)

Background: The determination of plasma metanephrines (MNs) provides a highly sensitive test for the diagnosis of catecholamine producing tumors. Chromatographic determinations with electrochemical or mass spectrometric detections are the methods of choice, but immunological assays have been developed. This study evaluated the clinical performances of a radioimmunoassay for free MNs in plasma., Methods: MNs, normetanephrine (NMN) and metanephrine (MN) and catecholamines, norepinephrine (NE) and epinephrine (E) were determined in plasma and urine of 533 patients suspected of catecholamine producing tumor. Urinary and plasma catecholamines and urinary MNs were determined by HPLC using amperometric detection. Plasma MNs were purified by solid phase chromatography and quantified by a specific radioimmunoassay., Results: Fifty-nine patients had tumors (13 paraganglioma and 46 pheochromocytoma) and the diagnosis was excluded in 474 patients. Receiver operator characteristic curves have identified optimal thresholds at 100 pg/mL for plasma NMN (sensitivity 96.6% and specificity 95.8%) and 70 pg/mL for plasma MN (sensitivity 61.0% and specificity 96.8%). These cut-off values were lower than those suggested by the manufacturer (170 and 100 pg/mL, respectively). The sensitivity of combined MNs was similar in plasma (100%) and urine (98%) but higher than that of urinary catecholamines (85%, p<0.001). The specificity of combined MNs in plasma (95%) was higher than urinary MNs (85%, p<0.001) and plasma catecholamines (75%, p<0.001)., Conclusions: Plasma-free and urinary-total MNs have a better discriminative power than catecholamines in the diagnosis of catecholamines producing tumors. Using these established cut-offs, measurement of plasma-free MN by radioimmunoassay represents an effective alternative to chromatographic methods.

Adrenal phaechromocytomas and extra-adrenal sympathetic paragangliomas (PPGLs) are rare neuroendocrine tumours, characterised by production of the catecholamines: noradrenaline, adrenaline and dopamine. Tumoural secretion of catecholamines determines their clinical presentation which is highly variable among patients. Up to 10-15% of patients present entirely asymptomatic and in 5% of all adrenal incidentalomas a PPGL is found. Therefore, prompt diagnosis of PPGL remains a challenge for every clinician. Early consideration of the presence of a PPGL is of utmost importance, because missing the diagnosis can be devastating due to potential lethal cardiovascular complications of disease. First step in diagnosis is proper biochemical analysis to confirm or refute the presence of excess production of catecholamines or their metabolites. Biochemical testing is not only indicated in symptomatic patients but also in asymptomatic patients with adrenal incidentalomas or identified genetic predispositions. Measurements of metanephrines in plasma or urine offer the best diagnostic performance and are the tests of first choice. Paying attention to sampling conditions, patient preparation and use of interfering medications is important, as these factors can largely influence test results. When initial test results are inconclusive, additional tests can be performed, such as the clonidine suppression test. Test results can also be used for estimation of tumour size or prediction of tumour location and underlying genotype. Furthermore, tumoural production of 3-methoxytyramine is associated with presence of an underlying SDHB mutation and may be a biomarker of malignancy.

Objective: Reviewing the clinical outcomes of a large kindred with a RET p.Gly533Cys mutation, 10 years after the first description of this kindred, has provided an important set of clinical data for healthcare decision-making., Design and Patients: We identified 728 RET533 Brazilian relatives, spread out over 7 generations. We performed clinical examination, biochemical and imaging analyses in the proband and in 103 carriers., Measurement and Results: The proband has been followed without evidence of structural disease in the last 10 years but with elevated calcitonin. The clinical and surgical features of 60 thyroidectomized RET533 relatives were also described. Forty-six patients had MTC (21-72 years), and 11 patients had C-cell hyperplasia (CCH) (5-42 years). Twelve MTC patients with lymph node metastases had a tumour size of 0·7-2·8 cm. Calcitonin level and CEA were correlated with disease stage, and none of the patients presented with an altered PTH or metanephrine. A 63-year-old woman developed pheochromocytoma and breast cancer. Two other RET533 relatives developed lung squamous cell carcinoma and melanoma., Conclusions: A vast clinical variability in RET533 presentation was observed, ranging from only an elevated calcitonin level (3%) to local metastatic disease (25%). Many individuals were cured (42%) and the majority had controlled chronic disease (56%), reinforcing the need for individualized ongoing risk stratification assessment. The importance of this update relies on the fact that it allows us to delineate the natural history of RET 533 MEN2A 10 years after its first description., (© 2013 John Wiley & Sons Ltd.)

Background: Medication-related interferences with measurements of catecholamines and their metabolites represent important causes of false-positive results during diagnosis of phaeochromocytomas and paragangliomas (PPGLs). Such interferences are less troublesome with measurements by liquid chromatography with tandem mass-spectrometry (LC-MS/MS) than by other methods, but can still present problems for some drugs. Levodopa, the precursor for dopamine used in the treatment of Parkinson's disease, represents one potentially interfering medication., Methods: Plasma and urine samples, obtained from 20 Parkinsonian patients receiving levodopa, were analysed for concentrations of catecholamines and their O-methylated metabolites by LC-MS/MS. Results were compared with those from a group of 120 age-matched subjects and 18 patients with PPGLs., Results: Plasma and urinary free and deconjugated (free + conjugated) methoxytyramine, as well as urinary dopamine, showed 22- to 148-fold higher (P < 0.0001) concentrations in patients receiving levodopa than in the reference group. In contrast, plasma normetanephrine, urinary noradrenaline and urinary free and deconjugated normetanephrine concentrations were unaffected. Plasma free metanephrine, urinary adrenaline and urinary free and deconjugated metanephrine all showed higher (P < 0.05) concentrations in Parkinsonian patients than the reference group, but this was only a problem for adrenaline. Similar to normetanephrine, plasma and urinary metanephrine remained below the 97.5 percentiles of the reference group in almost all Parkinsonian patients., Conclusions: These data establish that although levodopa treatment confounds identification of PPGLs that produce dopamine, the therapy is not a problem for use of LC-MS/MS measurements of plasma and urinary normetanephrine and metanephrine to diagnose more commonly encountered PPGLs that produce noradrenaline or adrenaline.

Measuring the levels of the plasma free metanephrines (PFMs) represents a recently developed and promising test for the diagnosis of pheochromocytoma in the United States and Europe. As this test has not yet been evaluated in Japan, it is necessary to evaluate the diagnostic efficacy of measuring the levels of PFMs compared with the standard measurement of the urinary excretion of metanephrines (uMNs) whose reliability is well established to detect of pheochromocytoma. A total of 101 Japanese subjects clinically suspected of having pheochromocytoma in were included in this study. Subsequently, we prospectively measured the PFMs levels in all patients, compared with those of biochemical markers of the catecholamine secretion and metabolisms in the plasma and urine. All subjects with adrenal tumors underwent tumor excision. Data were available for 84 of the 101 patients, 47 of whom had histopathologically proven pheochromocytoma and 37 were finally diagnosed with non-pheochromocytoma. The results of comparisons in the accuracy of measurement for diagnosis of pheochromocytoma between PFMs and the urinary excretion of metanephrines (uMNs) were 0.980 VS 0.951 for AUC of receiver operatorating characteristic (ROC) curve, 0.957 VS 0.894 for sensitivity, and 0.973 VS 0.946 for specificity, respectively. Although the differences were small, the results of our study definitely demonstrated that measurement of PFMs was not inferior to standard urinary metanephrines (uMNs) measurement, which is established to be the most reliable biochemical method to detect pheochromocytoma. This study clearly shows measuring the PFMs levels to be a reliable and efficient method for diagnosing pheochromocytoma in Japanese patients, as demonstrated in previous reports.

Objective: evaluate the assay of urinary metanephrines in diagnosis of pheochromocytoma (PH) and determine diagnostic cut-off values., Methods: this is a retrospective study about 87 patients suspected of pheochromocytoma,whose of 24-h urinary fractionated metanephrine was measured. These cases were collected from Internal Medecine Departments (A and B) at Charles Nicolle's Hospital. Two groups of patients were studied: a pheochromocytoma group (n=33) with a histologically-proven pheochromocytoma and a control group of 54 patients. Receiver Operating Characteristic (ROC) curves were used to determine the best sensitivities and specificities., Results: The analysis of biological parameters showed that means and standard deviation of urinary fractionated metanephrines in pheochromocytoma group were significantly higher than those of control group. Sensitivity and specificity of urinary normetanephrine test (95% and 98.1% respectively) were higher than those of urinary metanephrine and 3-methoxytyramine. A correlation between urinary normetanephrine and tumor size of pheochromocytoma was found., Conclusion: Urinary fractionated metanephrines is an efficient biochemical test for the diagnosis of pheochromocytoma.

For more than 20 years, measurement of catecholamines in plasma and urine in clinical chemistry laboratories has been the cornerstone of the diagnosis of neuroendocrine tumors deriving from the neural crest such as pheochromocytoma (PHEO) and neuroblastoma (NB), and is still used to assess sympathetic stress function in man and animals. Although assay of catecholamines in urine are still considered the biochemical standard for the diagnosis of NB, they have been progressively abandoned for excluding/confirming PHEOs to the advantage of metanephrines (MNs). Nevertheless, catecholamine determinations are still of interest to improve the biochemical diagnosis of PHEO in difficult cases that usually require a clonidine-suppression test, or to establish whether a patient with PHEO secretes high concentrations of catecholamines in addition to metanephrines. The aim of this chapter is to provide an update about the catecholamine assays in plasma and urine and to show the most common pre-analytical and analytical pitfalls associated with their determination., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

A commonly received question in the clinical laboratory is as follows: what is the best test for pheochromocytoma? A widely variable presentation and potentially catastrophic consequence make this a feared neoplasm despite its infrequent encounter. Because various biochemical testing modalities are available, test selection is often confusing. This selection process can be made easier through a better understanding of catecholamine producing neoplasms. The aim of this article is to provide a review of catecholamine producing neoplasms and give recommendations on appropriate test selection.

Objective: We introduce a novel liquid chromatographic tandem-mass spectrometric method for simultaneous measurements of urinary catecholamines and their free O-methylated metabolites, which we compare to the deconjugated metabolites., Methods: Method performance was validated for recovery, linearity, precision and accuracy, analyte stability, ion suppression and carry over. Results from 53 patients with and 138 volunteers without pheochromocytoma were compared., Results: Analyte recoveries ranged from 60 to 96% and intra- and inter-assay coefficients of variation from 2.7 to 13.2%. The method showed excellent linearity over 3 orders of magnitude with analytical sensitivity sufficient to measure to 1.2 nmol/L. Free O-methylated metabolites were excreted at less than 20% the rates of the deconjugated metabolites, but were easily measureable. Increases in urinary normetanephrine in pheochromocytoma patients relative to volunteers were higher for free than deconjugated metabolites and higher for both than for norepinephrine (10 vs 5.5 vs 3.7 fold increases). In contrast, relative increases in urinary free versus deconjugated metanephrine (2.7 and 3.2) and methoxytyramine (2.1 and 1.9) did not differ, but for methoxytyramine were larger than for dopamine (1.2)., Conclusion: Measurements of urinary catecholamines and their free O-methylated metabolites by our method provide potential advantages over urinary deconjugated metanephrines for diagnosis of pheochromocytoma., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Context: Follow-up after adrenalectomy for pheochromocytoma is recommended because of a recurrence risk. During follow-up, plasma and/or urinary metanephrine (MN) and normetanephrine (NMN) are interpreted using reference ranges obtained in healthy subjects., Objective: Because adrenalectomy may decrease epinephrine production, we compared MN and NMN concentrations in patients after adrenalectomy to concentrations in a healthy reference population., Design: A single-center cohort study was performed in pheochromocytoma patients after adrenalectomy between 1980 and 2011., Subjects: Seventy patients after unilateral and 24 after bilateral adrenalectomy were included., Main Outcome Measures: Plasma-free and urinary-deconjugated MN and NMN determined at 3 to 6 months and annually until 5 years after adrenalectomy were compared with concentrations in a reference population. Data are presented in median (interquartile range)., Results: Urinary and plasma MN concentrations 3 to 6 months after unilateral adrenalectomy were lower compared with the reference population (39 [31-53] μmol/mol creatinine and 0.14 [0.09-0.18] nmol/L vs 61 [49-74] μmol/mol creatinine and 0.18 [0.13-0.23] nmol/L, respectively, both P < .05). Urinary MN after bilateral adrenalectomy was reduced even further (7 [1-22] μmol/mol creatinine; P < .05). Urinary and plasma NMN were higher after unilateral adrenalectomy (151 [117-189] μmol/mol creatinine and 0.78 [0.59-1.00] nmol/L vs 114 [98-176] μmol/mol creatinine and 0.53 [0.41-0.70] nmol/L; both P < .05). Urinary NMN after bilateral adrenalectomy was higher (177 [106-238] μmol/mol creatinine; P < .05). Changes in urinary and plasma MNs persisted during follow-up., Conclusion: Concentrations of MN are decreased, whereas NMN concentrations are increased after unilateral and bilateral adrenalectomy. Adjusted reference values for MN and NMN are needed in the postsurgical follow-up of pheochromocytoma patients.

Background & Objectives: Plasma and urinary metanephrines are used as screening tests for the diagnosis of phaeochromocytoma. The recommended cut-off levels are not standardized. This study was conducted to identify a cut-off level for 24 h urinary fractionated metanephrines viz. metanephrine (uMN) and normetanephrine (uNMN) using enzyme immunoassay for the diagnosis of phaeochromocytoma., Methods: Consecutive patients suspected to have phaeochromocytoma were included in the study. uMN and uNMN in 24 h urinary sample were measured using a commercial ELISA kit., Results: Overall, 72 patients were included over a period of 18 months. Twenty patients had histopathologically confirmed phaeochromocytoma and in 52 patients phaeochromocytoma was ruled out. Using the upper limit of normal stated by the assay manufacturer as the cut-off, uMN >350 μg/day had a low sensitivity and uNMN >600 μg/day had a poor specificity. By increasing the cut-off value of uNMN to twice the upper limit, specificity increased significantly without much loss in sensitivity. Combining uMN and uNMN using a cut-off twice the upper limit improved the diagnostic performance - sensitivity (95%); specificity (92.3%); positive predictive value (PPV - 82.6%); negative predictive value (NPV - 98%). In subsets of patients with a variable pretest probability for phaeochromocytoma, the PPV correlates well with the occurred of these tumors decreased, while the NPV remained at 100 per cent., Interpretation & Conclusions: ELISA is a simple and reliable method for measuring uMN and uNMN. The test has a good NPV and can be used as an initial screening test for ruling out phaeochromocytoma. Each hospital will have to define the cut-off value for the assay being used, choosing a proper control population.

Background: Measurement of fractionated plasma or urine metadrenalines is the recommended screening test in the diagnosis of phaeochromocytoma, with clinical cut-offs geared towards diagnostic sensitivity. Current practice at Salford Royal Hospital is to add urine catecholamines onto samples with raised urine metadrenalines, with the aim of adding specificity to a diagnosis of phaeochromocytoma., Methods: This practice was reviewed by identifying a series of patients with raised urine metadrenalines who had catecholamines reflectively added. A total of 358 samples were identified from 242 patients, of which 228 had urine catecholamines measured., Results: A diagnosis of 'phaeochromocytoma' (n = 41) or 'no phaeochromocytoma' (n = 90) was obtained in 131 of 228 patients, giving raised urine metadrenalines a positive predictive value for phaeochromocytoma of 31%. The finding of increased urine catecholamines in samples with raised urine metadrenalines increased specificity for phaeochromocytoma to 70%. However, 95% diagnostic specificity for phaeochromocytoma could be achieved by the introduction of a second cut-off for urine metadrenalines geared towards maximizing specificity., Conclusions: Consideration of the degree of increase in urine metadrenalines is a superior method of determining the likelihood of phaeochromocytoma than measurement of urine catecholamines.

The silent pheochromocytoma, a hidden form of pheochromocytoma, exposes the patient to an increased risk of mortality if the diagnosis is not established on time. Biological diagnosis of pheochromocytoma can be difficult. Catecholamine secretion is dependent on tumor size and a large number of physiological, pharmacological, lifestyle modifications and sampling conditions influence the measurement of urinary and plasma metanephrines. The prevalence of pheochromocytoma is 2% among adrenal incidentaloma smaller than 3 cm (2/3 of tumors). Recent studies suggest the almost zero risk of pheochromocytoma among these tumors if they are hypodense (<10 housefield units) on adrenal tomography. Addison's disease is a pathology affecting about 1 in 8000. Immunopathology is still unknown, but some elements advocated the hypothesis of a predominant cell-mediated immunity in particular Interferon-gamma production by CD4 T lymphocytes in the presence of an epitope from the 21-hydroxylase, as well as IgG1 subtype produced by activated B lymphocytes, autoantibodies do appear to be a simple marker of the disease. Subclinical Addison's disease is defined by the presence of anti-21-hydroxylase autoantibodies, without clinical symptoms. It evolves faster to the clinical phase in young subjects, male, having high levels of autoantibodies and with an initially impaired adrenal function. Dosage of ACTH, plasma renin active, and basal cortisol and after Synacthen allow to discriminate the subjects with low or high risk of evolution and establish an appropriate monitoring., (Copyright © 2012 Elsevier Masson SAS. All rights reserved.)

Background: Catecholamine-producing neuroendocrine tumours are found in chromaffin cells of the adrenal medulla (phaeochromocytoma) or extra-adrenal paraganglia (paraganglioma), known collectively as PPGLs. In approximately a quarter or more of cases of PPGL, these rare tumours arise as a result of germline mutations of several tumour susceptibility genes. At the Crosshouse laboratory, urine tests include free metadrenalines (fMAs) (also known as free metanephrines) which demonstrate superior sensitivity over that obtained by urinary vanillyl mandelic acid, catecholamines or plasma catecholamines in the diagnosis of PPGL. This retrospective audit was to determine if urinary fMAs offered discrimination among the hereditary forms of PPGL., Methods: Retrospective biochemical and genetic data were gathered from 1997 to 2011. The identified urine specimens were those obtained at the time of first diagnosis or recurrence of PPGL. Results of catecholamines and metabolites were standardized as multiples of their respective relevant upper reference limits (URLs)., Results: Results were available for 29 affected patients (15 females and 14 males), median age 26 (range 9-63) years, comprising three mutation groups: succinate dehydrogenase subunit B or D ([SDHB/D] 16 patients), multiple endocrine neoplasia type 2 ([MEN 2] 6 patients) and von Hippel-Lindau disease ([VHL] 7 patients). The parent catecholamines exhibited increased values for noradrenaline (NA) and/or adrenaline (AD) for 25/29 (86.2%) patients. Either or both free normetadrenaline (fNMA) and fMA were elevated in 29/29 (100%) patients., Conclusions: The ratio of the multiples of URL for fMA/fNMA displayed a clearer separation of MEN 2 patients from those with SDHB/D or VHL than did the equivalent AD/NA ratio.

Adrenal pheochromocytomas are neoplasms characterized by catecholamine excess. Determination of metanephrines by high-pressure liquid chromatography has been well established for the diagnosis of pheochromocytomas, demonstrating high sensitivity and specificity. This study evaluates the diagnostic value of newly available enzyme immunoassays for metanephrines in plasma and urine. Chromogranin A was studied as a potential additional diagnostic tool. Spontaneous blood samples and 24-h urine samples were collected in 149 subjects, including 24 histologically proven pheochromocytomas, 17 aldosterone-secreting and 21 cortisol-secreting adrenal adenomas, 30 nonfunctioning adrenal masses, 15 patients with essential hypertension and 42 healthy normotensive volunteers. Plasma and urinary metanephrine and normetanephrine as well as chromogranin A were determined and putative thresholds were calculated by ROC analysis. Plasma free normetanephrine was found to be the best single parameter with the highest sensitivity (89.5%) and specificity (98.3%) using a threshold of 167 pg/ml. Analysis of the combination of plasma free metanephrines revealed a similar sensitivity with lower specificity of 90.0%. Considering both urinary parameters demonstrated a slightly higher sensitivity (92.9%) with lower specificity (77.6%). ROC analysis revealed a threshold of 215 µg/l for chromogranin A with rather low sensitivity (73.9%) and specificity (74.2%). A weak positive correlation was found between the tumor size of pheochromocytomas and plasma metanephrine (r = 0.53, p ≤ 0.05) as well as chromogranin A (r = 0.60, p ≤ 0.01). In conclusion, plasma free and urinary metanephrines measured by enzyme immunoassays are convenient and reliable parameters for the diagnosis of pheochromocytoma. In contrast, CgA demonstrated poor sensitivity and specificity., (© J. A. Barth Verlag in Georg Thieme Verlag KG Stuttgart · New York.)

A 63-year-old lady presented with suprapelvic pain, weight loss and night sweats. On examination, she was noted to be hypertensive with a distended abdomen. Imaging (CT) revealed a 9.5 cm retroperitoneal mass with a high degree of vascularity and necrotic centre. The patient's urinary and plasma catecholamines were significantly raised and subsequent radio-isotope scan suggested the tumour was likely to be of a neuroendocrine nature. A diagnosis of a malignant paraganglioma was made. Malignant paragangliomas derive from sympathetic tissue and secrete catecholamines. Diagnostic uncertainty might lead to biopsy of tumour but this carries a high-risk of catecholamine-induced complications such as hypertensive crisis, cardiac arrhythmias and cardiac ischaemia and must be avoided.

Background: The quantification of total (free+sulfated) metanephrines in urine is recommended to diagnose pheochromocytoma. Urinary metanephrines include metanephrine itself, normetanephrine and methoxytyramine, mainly in the form of sulfate conjugates (60-80%). Their determination requires the hydrolysis of the sulfate ester moiety to allow electrochemical oxidation of the phenolic group. Commercially available urine calibrators and controls contain essentially free, unhydrolysable metanephrines which are not representative of native urines. The lack of appropriate calibrators may lead to uncertainty regarding the completion of the hydrolysis of sulfated metanephrines, resulting in incorrect quantification., Methods: We used chemically synthesized sulfated metanephrines to establish whether the procedure most frequently recommended for commercial kits (pH 1.0 for 30 min over a boiling water bath) ensures their complete hydrolysis., Results: We found that sulfated metanephrines differ in their optimum pH to obtain complete hydrolysis. Highest yields and minimal variance were established for incubation at pH 0.7-0.9 during 20 min., Conclusion: Urinary pH should be carefully controlled to ensure an efficient and reproducible hydrolysis of sulfated metanephrines. Synthetic sulfated metanephrines represent the optimal material for calibrators and proficiency testing to improve inter-laboratory accuracy., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Objective: Pheochromocytomas are characterized by a high attenuation value on unenhanced computed tomography (CT). It is not known whether pheochromocytoma could be ruled out as a cause of adrenal incidentalomas on the basis of unenhanced attenuation values only., Design: We retrospectively evaluated the outcome of routine biochemical screening for pheochromocytoma in a series of adrenal incidentalomas in relationship to the unenhanced attenuation values on CT., Methods: An unenhanced CT was available in 174 of 184 patients with 214 adrenal incidentalomas. All patients were screened for pheochromocytoma with 24-h urinary metanephrines and normetanephrines and for hypercortisolism (1 mg dexamethasone test and ACTH). Hypertensive patients were screened for aldosterone overproduction (aldosterone to renin ratio and 24 h urinary aldosterone). The results were compared between incidentalomas with high [≥10 Hounsfield units (HU)] and low (<10 HU) unenhanced attenuation values., Results: One hundred forty-six incidentalomas in 115 patients had an unenhanced HU less than 10. None of these patients had elevated 24-h fractionated urinary metanephrines or normetanephrines suggesting pheochromocytoma. Sixty-eight incidentalomas in 59 patients had an unenhanced HU of 10 or greater, and nine (15.2%) of these patients had surgically and histologically verified pheochromocytoma. Incidentalomas with a HU of 10 or greater were significantly larger (2.6 ± 1.5 vs. 2.3 ± 1.2 cm; P < 0.001), more often functional (27.9 vs. 8.9%, P < 0.001), and more often operated (44.1 vs. 10.2%; P < 0.001) than those with a Hounsfield unit less than 10., Conclusion: The results of this study indicate that routine biochemical screening of pheochromocytoma in small homogenous adrenal incidentalomas characterized by an unenhanced Hounsfield unit value less than 10 HU may not be necessary.

The diagnosis of pheochromocytoma depends on the documentation of catecholamine overproduction. The use of urinary fractionated metanephrines has recently become common for the diagnosis of pheochromocytoma. In order to avoid false positive and false negative results, optimal cut-off levels are necessary; however, there have been few published reports on whether different cut-off levels are needed to diagnose pheochromocytoma according to sex. We reviewed the medical records of 815 subjects (including 103 pheochromocytoma patients) whose of 24-h urinary fractionated metanephrine was measured using high-performance liquid chromatography methods and adrenal imaging at Samsung Medical Center. Receiver operating characteristic (ROC) curves were used to determine cut-off values according to sex. The upper limit values of fractionated metanephrine in healthy volunteers and the control group were significantly higher in male subjects compared with females. When we applied cut-off values according to sex, the diagnostic efficacies (defining a positive test as either metanephrine or normetanephrine levels above the cut-off value) were a sensitivity of 96% in male subjects and 98.1% in female subjects and a specificity of 88.6% in male subjects and 94.1% in female subjects. However, when we applied cut-off values without considering sex, the specificity decreased from 88.6% to 77.8% in male subjects. In this study, urinary fractionated metanephrines had a high level of sensitivity and specificity for the diagnosis of pheochromocytoma. However, diagnostic cut-off values were higher in male subjects than in female subjects. Therefore, different cut-off values may be needed according to sex to diagnose pheochromocytoma in Koreans.

Determination of urinary metanephrines is requested frequently for the differential diagnosis and monitoring of pheochromocytoma. Although numerous methods have been developed, interferences are common and hinder most available assays. This study describes the development, validation and implementation of a reliable high-throughput LC-MS/MS method for the measurement of metanephrine and normetanephrine in urine. Metanephrine and normetanephrine were isolated from urine samples subjected to acid hydrolysis using solid phase extraction on a mixed mode cation exchange sorbent in 96-well format. The extracts were injected directly onto a Restek perfluorophenyl column and separated isocratically in 0.2% formic acid in 5% methanol with a gradient cleanout step to 50% methanol. Detection was accomplished using an API 3200 triple quadrupole mass spectrometer with electrospray ionization in positive mode. Data were acquired in multiple reaction monitoring mode. Three transitions were monitored for metanephrine and its deuterated internal standard; two transitions were monitored for normetanephrine and its deuterated internal standard. Two quantification methods were used to address metanephrine interferences without reducing throughput. The method was linear to 15,000 nmol/L. The limits of detection and quantification were 2.5 and 10 nmol/L, respectively. Within run, between-day and total imprecision values were at or below 1.9%, 2.5% and 2.7% for both analytes. The method correlated well with our previously used GC-MS method. Injection-to-injection time was 6 min. The validated LC-MS/MS method for measurement of metanephrine and normetanephrine in urine specimens was placed into service in August 2010 and has performed exceptionally well., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Paragangliomas are rare, benign or less frequently malignant tumors developing from cells of the paraganglia, a diffuse neuroendocrine system dispersed from skull base to the pelvic floor. Although paragangliomas may arise in any portion of this system, they most commonly occur below the diaphragm. Even 50% of the tumors may be hereditary and therefore genetic testing should be taken into consideration in all patients with paragangliomas. In many patients their presence leads to headaches, palpitations, sweating, or hypertension. However, subjects with nonfunctional tumors are either asymptomatic at presentation or experience only local symptoms caused by the mass effect. Functional paragangliomas can be almost always revealed by measurements of plasma concentrations of free metanephrines or 24-hour urinary outputs of fractionated metanephrines and catecholamines. There are also several morphological and functional imaging methods available that help localize neoplasm and assess its extent. In this paper, we discuss the published literature on the etiopathogenesis, diagnostic work up and the different treatment options for patients with paraganglioma. This review looks also at the recent advances in the physiology and molecular basis of these tumors.

Background: A 59-year-old man presented for a follow-up, 6 years after surgery for a large pheochromocytoma. He had suffered from diabetes mellitus, hypertension and abdominal pain in the right flank region. Previous postoperative follow-up did not reveal tumor recurrence., Investigation: Measurement of plasma free metanephrine and normetanephrine by high-performance liquid chromatography and radioimmunoassay; 123I-metaiodobenzylguanidine (MIBG) scintigraphy; hybrid 123I-MIBG single-photon emission CT (SPECT)-CT; MRI; testing for plasma norepinephrine and epinephrine; intraoperative ultrasonography; histological staining for chromogranin A and synaptophysin; and postoperative 18F-dihydroxyphenylalanine (DOPA) PET scan., Diagnosis: Recurrent pheochromocytoma., Management: Laparotomy with tumor resection. Reduction of antihypertensive medications. Further follow-up by MRI, hybrid 123I-MIBG SPECT-CT and testing for plasma catecholamines and free metanephrines.

The aim of the study was to evaluate the prevalence of pheochromocytoma (PHEO) in patients with neurofibromatosis type 1 (NF1), and to analyze the behavior of some anthropometric and cardiovascular parameters. In 48 consecutive NF1 patients, urinary metanephrines and vanillylmandelic acid excretion were assessed. The body mass index (BMI), waist circumference (WC), ambulatory blood pressure monitoring (ABPM), echocardiography and ultrasound carotid arterial wall evaluation were performed. In NF1 patients, 11 (29.3%) had arterial hypertension, 7 (14.6%) had a PHEO. Four (57%) NF1 patients with PHEO were symptomatic at the diagnosis. In PHEO-NF1 patients, we revealed a lower BMI and WC values with respect to NF1 patients without PHEO and normal subjects (NSs) (p < 0.05), respectively. The nocturnal non-dipping pattern at the ABPM was present in 40.4% of NF1 patients, and in particular this phenomenon was present in PHEO-NF1 patients (71.4%). Left ventricular mass index and intima media thickness were significantly higher in NF1 patients as compared to NS (p < 0.05), particularly in NF1-PHEO patients (p < 0.05). In conclusions, these findings revealed high prevalence of PHEO in NF1 patients and suggest that, in addition to blood pressure, humoral factors (increased sympathetic activity or neurofibromin), influence the pathogenesis of remodeling of cardiovascular system.

Background: Measuring urinary fractionated metanephrines is one of the initial tests in the diagnosis of pheochromocytoma. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) represents the most specific and accurate technology for this purpose. The goal of this work was to develop a simple LC-MS/MS method for measuring metanephrines in urine., Methods: Each urine sample was complexed with diphenylboronic acid, and purified on a Bond-Elute Plexa cartridge. The extract was concentrated and analyzed on a short Atlantis T3 column in 8.5 min. Metanephrines and their deuterated internal standards were monitored in positive electrospray ionization mode by multiple reaction monitoring., Results: Ion suppression was observed, but was compensated for by the respective internal standard. The analytical measurement range was 0.2-27.4 μmol/L and 0.3-14.6 μmol/L for metanephrine and normetanephrine, respectively. The intra-assay and total coefficient of variation throughout the linear ranges was 2.03%-2.11% and 2.20%-3.80% for metanephrine, and 4.50%-8.09% and 9.00%-10.00% for normetanephrine, respectively. Comparison with a commercial HPLC method using patient samples (n=65) by Passing-Bablok regression showed a slope of 1.000 and 1.014, y-intercept of -0.080 and -0.067, a correlation coefficient of 0.8830 and 0.9022, and a mean difference of 14.0% and -0.43% for metanephrine and normetanephrine, respectively., Conclusions: This simple method for urine metanephrines is suitable for clinical use.

Background: Neuroblastoma is the most common extracranial solid tumour in childhood (8% of all childhood cancers), the most frequently diagnosed in infancy, and has one of the highest death rates, while chromaffin tumours rarely present in childhood. Both tumour types produce catecholamines and their metabolites. It is difficult to produce reference ranges for tests in children, and currently, no age-related medical decision limits for free metadrenalines (free metanephrines) in random urine specimens exist in the paediatric literature., Methods: Results of vanillylmandelic acid (VMA), 5-hydroxyindoleacetic acid, homovanillic acid (HVA), noradrenaline (NA), adrenaline, dopamine (DA), free normetadrenaline (fNMA), free metadrenaline and free 3-methoxytyramine (f3MT) in 1658 random urines obtained from infants, children and young adults were measured by high performance liquid chromatography with electrochemical detection. Specimens were excluded from consideration if obtained from the following categories, i.e. (a) harbouring neuroblastic, chromaffin, carcinoid or other tumours or malignancies; (b) medical conditions having known association with excess catecholamine excretion; (c) patients administered catecholamine or paracetamol; (d) overly dilute urine; and (e) manifesting outlying values following visual inspection., Results: There remained 872 specimens that were grouped into seven age ranges (<1; 1 or 2; 3 or 4; 5-7; 8-10; 11-13; 14-19 y) for which medical decision limits were determined for each analyte. There was no significant difference between the results for boys or girls. In 55 patients harbouring neuroblastic tumours, HVA (54/55), f3MT (14/16), VMA (45/53) and DA (43/53) were the most frequently elevated analytes at time of diagnosis. In 11 patients presenting in childhood with chromaffin tumours, fNMA (11/11) followed by NA (10/11) were the most frequently elevated. Discussion The likely reasons for outlying or missing values, together with the reasons for variation in the distinctive biochemical patterns of analytes exhibited in individuals harbouring either neuroblastic or chromaffin tumours are discussed.

"Tako-tsubo" cardiomyopathy is a condition characterized by a transitory left ventricular asinergia, induced by physical and emotional stress. In literature there are few cases of association between cardiomyopathy and pheochromocytoma. We described a case of a 72 year-old woman admitted in Emergency Room for chest pain associated with high blood pressure: the ECG showed non-ST elevation in leads III, AVF and V1. An echocardiogram showed global reduction in contractility (EF 40%) with apical akinesia. The coronary angiography showed coronary without stenosis while left ventriculography showed an average apical akinesia of the anterior wall with enhanced contractility of basal segments. Subsequently, the patient continued to present episodes of tremors associated with high blood pressure and therefore was made the determination of urinary metanephrines and urinary vanilmandelic acid that were both high. A subsequent abdomen MRI showed a 32 mm left adrenal lesion with arterial phase impregnation. The diagnosis of left adrenal pheochromocytoma was made and the tumor, after appropriate preoperative pharmacological preparation with α-blockers, was removed surgically. In conclusion, the unexplained transitory left ventricular asinergia alert the clinician of an underlying disorder, such as pheochromocytoma, the early detection of which is crucial to the prognosis.

The aim of the study is to assess whether occupational exposure to urban stressors could cause alterations in urinary metanephrines levels in traffic policemen vs administrative staff of municipal police. A total of 258 subjects were included in the study: 129 traffic policemen exposed to urban stressors (68 males and 61 females) and 129 controls (68 males and 61 females). Urinary metanephrines mean levels were significantly higher in male traffic policemen compared to controls (p < 0.01). No significant differences were in female traffic policemen compared to controls. In the control group, urinary metanephrines mean levels were significantly higher in females compared to males (p < 0.01). There were no significant differences in urinary metanephrines mean levels in female traffic policemen vs male traffic policemen. The increase in urinary metanephrines mean levels observed in male exposed compared to controls could be related to chronic occupational exposure to low doses of chemical, physical and psychosocial urban stressors.

Paragangliomas are rare tumors arising from extraadrenal chromaffin cells. We report a 43-year-old man who presented with abdominal pain. An abdominal computed tomography scan revealed a large retroperitoneal mass. During an endoscopic biopsy of this tumor, the patient experienced marked hemodynamic fluctuations with tachycardia and high blood pressure, and an extraadrenal pheochromocytoma was suspected. Measurements of plasma and urinary catecholamines and urinary total metanephrines ruled in the diagnosis. Echocardiography disclosed acute myocardial dysfunction that returned to normal after surgical resection of the paraganglioma. This report also underlines the importance of the anesthetic preparation and monitoring around the surgical procedure and the need of a long-term follow-up to detect malignant paraganglioma in the absence of histological criteria of benign tumor., (Copyright © 2010 Société nationale française de médecine interne (SNFMI). Published by Elsevier SAS. All rights reserved.)

Background: Pheochromocytomas are rare catecholamine-producing tumors derived in more than 30% of cases from mutations in 9 tumor-susceptibility genes identified to date, including von Hippel-Lindau tumor suppressor (VHL); succinate dehydrogenase complex, subunit B, iron sulfur (Ip) (SDHB); and succinate dehydrogenase complex, subunit D, integral membrane protein (SDHD). Testing of multiple genes is often undertaken at considerable expense before a mutation is detected. This study assessed whether measurements of plasma metanephrine, normetanephrine, and methoxytyramine, the O-methylated metabolites of catecholamines, might help to distinguish different hereditary forms of the tumor., Methods: Plasma concentrations of O-methylated metabolites were measured by liquid chromatography with electrochemical detection in 173 patients with pheochromocytoma, including 38 with multiple endocrine neoplasia type 2 (MEN 2), 10 with neurofibromatosis type 1 (NF1), 66 with von Hippel-Lindau (VHL) syndrome, and 59 with mutations of SDHB or SDHD., Results: In contrast to patients with VHL, SDHB, and SDHD mutations, all patients with MEN 2 and NF1 presented with tumors characterized by increased plasma concentrations of metanephrine (indicating epinephrine production). VHL patients usually showed solitary increases in normetanephrine (indicating norepinephrine production), whereas additional or solitary increases in methoxytyramine (indicating dopamine production) characterized 70% of patients with SDHB and SDHD mutations. Patients with NF1 and MEN 2 could be discriminated from those with VHL, SDHB, and SDHD gene mutations in 99% of cases by the combination of normetanephrine and metanephrine. Measurements of plasma methoxytyramine discriminated patients with SDHB and SDHD mutations from those with VHL mutations in an additional 78% of cases., Conclusions: The distinct patterns of plasma catecholamine O-methylated metabolites in patients with hereditary pheochromocytoma provide an easily used tool to guide cost-effective genotyping of underlying disease-causing mutations.

Introduction: Normetanephrine and metanephrine are intermediate metabolites of noradrenaline and adrenaline metabolism. To assess whether normetanephrine and metanephrine analysis may aid in the diagnosis of Neuroblastoma, a reference interval for these metabolites must first be established., Aim: The overall aim of this study was to establish a paediatric age-related reference interval for the measurement of total fractionated metanephrines., Methods: A total of 267 urine samples were analysed following acid hydrolysis. This releases the metanephrines from their sulphate-bound metabolites. The samples were analysed using reverse phase high-performance liquid chromatography with electro-chemical detection on a Gilson automated sequential trace enrichment of dialysate sample system., Results: Data were analysed using Minitab Release version 14. Outliers were removed using the Dixon/Reed one-third rule. Partitioning of the age groups was achieved using Harris and Boyd's standard normal deviate test. Non-parametric analysis of the data was performed, followed by the establishment of the 2.5th and the 97.5th reference limits., Conclusions: The established reference intervals are described in Table 2.

Aim: This study aimed to determine the prevalence of excess dopamine in relation to clinical symptoms and nuclear imaging in head and neck paraganglioma (PGL) patients., Patients and Methods: Thirty-six consecutive patients with head and neck PGLs, evaluated between 1993 and 2009, were included. Clinical symptoms, dopamine excess (urinary 3-methoxytyramine (3-MT) or dopamine and/or plasma dopamine or 3-MT) and (nor)epinephrine excess (urinary (nor)metanephrine) as well as (111)In-octreotide and (123)I-metaiodobenzylguanide (MIBG) scintigraphy were documented., Results: Dopamine excess was found in seven patients (19.4%), but was unrelated to clinical signs and symptoms. Excretion of other catecholamines was unremarkable, except in one patient with adrenal pheochromocytoma. (123)I-MIBG uptake (present in 36.1% of patients) was associated with dopamine excess (p = 0.03)., Conclusion: Dopamine excess is present in a considerable percentage of patients with head and neck PGL, and its measurement may be useful in follow-up. Measurement of other catecholamines is necessary to rule out co-existent pheochromocytoma.

Background: Urinary catecholamines and metanephrines have been proposed as a diagnostic tool for identifying canine pheochromocytomas, but the effects of critical illness on urine concentrations of catecholamines and metanephrines currently are unknown., Objectives: To examine the effects of illness on urine concentrations of catecholamines and metanephrines in dogs., Animals: Twenty-five critically ill dogs and 25 healthy age- and sex-matched control dogs., Methods: Prospective observational study. Urine was collected from healthy and critically ill dogs, and urine concentrations of epinephrine, norepinephrine, metanephrine, and normetanephrine were measured by high-performance liquid chromatography with electrochemical detection. Urinary catecholamine and metanephrine:creatinine ratios were calculated and compared between groups., Results: Urinary epinephrine, norepinephrine, metanephrine, and normetanephrine:creatinine ratios were higher in critically ill dogs when compared with a healthy control population (P=.0009, P<0.0001, P<0.0001, and P<0.0001, respectively)., Conclusions and Clinical Importance: Illness has a significant impact on urinary catecholamines and their metabolites in dogs. Further investigation of catecholamine and metanephrine concentrations in dogs with pheochromocytomas is warranted to fully evaluate this test as a diagnostic tool; however, the findings of this study suggest that the results may be difficult to interpret in dogs with concurrent illness., (Copyright © 2010 by the American College of Veterinary Internal Medicine.)

Background: Measurement of metadrenalines has been recommended in the investigation of phaeochromocytoma. Urinary assays remain the most common; however, drug interference is still one of the main challenges for analytical systems. We have developed a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of total urinary normetadrenaline and total urinary metadrenaline, which does not require extraction procedures prior to analysis., Method: Total urinary normetadrenaline and total urinary metadrenaline were individually quantified by electrospray ionization in the multiple-reaction monitoring mode. Deuterated internal standards were used and an acid hydrolysis step was used to convert conjugated metabolites into free metadrenalines. Chromatographic separation was achieved using a Phenomenex Luna 3 micro PFP column followed by analysis on an API 3200 LC-MS/MS., Results: Linearity was exhibited across the calibration range for both normetadrenaline (r = 1, P < 0.0001) and metadrenaline (r = 1, P < 0.0001) with the limit of quantification of 0.05 and 0.02 micromol/L, respectively. Intra-assay imprecision for both normetadrenaline and metadrenaline was less than 5.5% with % coefficient of variations of less than 4%. Inter-assay imprecision was less than 13%. Neither noradrenaline or adrenaline interfere with the assay as determined by the spiking of samples with high concentrations of noradrenaline or adrenaline (P > 0.05). Acceptable analytical performance was seen with comparison to a high-performance liquid chromatography method and on External Quality Assessment returns., Conclusions: An analytically simple and sensitive method has been developed and evaluated for the analysis of total urinary normetadrenaline and total urinary metadrenaline which is now in routine use.

Background: Urinary catecholamines and metanephrines are used for the diagnosis of pheochromocytoma (PHEO) in dogs. Hyperadrenocorticism (HAC) is an important differential diagnosis for PHEO., Objectives: To measure urinary catecholamines and metanephrines in dogs with HAC., Animals: Fourteen dogs with HAC, 7 dogs with PHEO, and 10 healthy dogs., Methods: Prospective clinical trial. Urine was collected during initial work-up in the hospital; in dogs with HAC an additional sample was taken at home 1 week after discharge. Parameters were measured using high-pressure liquid chromatography and expressed as ratios to urinary creatinine concentration., Results: Dogs with HAC had significantly higher urinary epinephrine, norepinephrine and normetanephrine to creatinine ratios than healthy dogs. Urinary epinephrine, norepinephrine, and metanephrine to creatinine ratios did not differ between dogs with HAC and dogs with PHEO, whereas the urinary normetanephrine to creatinine ratio was significantly higher (P= .011) in dogs with PHEO (414, 157.0-925.0, median, range versus (117.5, 53.0-323.0). Using a cut-off ratio of 4 times the highest normetanephrine to creatinine ratio measured in controls, there was no overlap between dogs with HAC and dogs with PHEO. The variables determined in urine samples collected at home did not differ from those collected in the hospital., Conclusion and Clinical Importance: Dogs with HAC might have increased concentrations of urinary catecholamines and normetanephrine. A high concentration of urinary normetanephrine (4 times normal), is highly suggestive of PHEO., (Copyright © 2010 by the American College of Veterinary Internal Medicine.)

The silica monolith with ionizable silanol groups and large surface area was found able to function as an offline cation exchange solid phase extraction (SPE) cartridge for extracting polar analytes. The prepared cartridge was housed in a 2-mL syringe fixed over a SPE vacuum manifold. The unique property of this silica monolithic cartridge was demonstrated by extracting epinephrine, normetanephrine and metanephrine from urine samples. These analytes were chosen as model compounds for testing because of their high hydrophilicity, and being candidates monitored for clinical diagnosis. The extracted analytes, after concentration and reconstitution were then quantitated by high-performance liquid chromatography coupled to mass spectrometer (HPLC/ESI/MS). Multiple reactions monitoring was carried out with transitions: 184-->107, 184-->134 and 198-->148 for analyzing epinephrine, normetanephrine and metanephrine, respectively. The limit of detection was 3 ng/mL for metanephrine and 5 ng/mL for normetanephrine and epinephrine. The relative standard deviations of measurements ranged from 2 to 10%. The sorbent offered good linearity with coefficient of determination (r(2))>0.99, over a concentration range of 20-200 ng/mL. The relative recoveries ranged from 60 to 67%, 55 to 59% and 99 to 105% for epinephrine, normetanephrine and metanephrine, respectively. The prepared cartridge had shown potential and was found robust in extracting the polar analytes repeatedly without any significant loss in efficiency., (Copyright 2010 Elsevier B.V. All rights reserved.)

Aim: The aim was to investigate whether high catecholamine (CA) excreters would respond less well to a group cognitive behaviour therapy (CBT) treatment for depression than others., Method: A sample of 70 adults with depression symptoms participated in a 12-week course of group CBT. Participants' 24 hour urinary catecholamine levels at pre-therapy and post-therapy were used to classify them as High (N = 10); Low (N = 33) or Mixed (N = 27) according to a cut-off one standard deviation above a published mean for healthy adults. Beck Depression Inventory (BDI) and cognitions questionnaire (Automatic Thoughts Questionnaire; Beck Hopelessness Scale and Dysfunctional Attitudes Scale) were used., Results: Repeated measures ANOVA analyses showed an equal rate of mood improvement in all three groups over the course of CBT, despite the fact that the High excreters were on average more depressed throughout the study. Changes in depression symptoms were mirrored by improvements in cognitive measures in the three catecholamine groups., Conclusion: This study indicates that adults showing a biological marker of depression (elevated catecholamine levels) are equally able to benefit from CBT treatment as adults without this marker.

Background: Plasma free and urinary metanephrines are recognized biomarkers for the assessment of pheochromocytoma. Plasma total metanephrines with a long half-life may represent another useful biomarker., Objective: The aim of this study is to evaluate the diagnostic performances of plasma total metanephrines alone or combined with free metanephrines and fractionated 24-h urinary metanephrines., Methods: A retrospective, case-control diagnostic test study was conducted between 1999 and 2007 in two university hospitals in Switzerland and two institutions in France. The patients included 46 cases with histologically proven pheochromocytoma, and 181 controls suspected of tumor with negative investigations and 3-year follow-up. None had renal dysfunction. Sensitivity and specificity were compared after expressing each measurement result as a ratio over its upper reference limit, adding the ratios of normetanephrine and metanephrine, and defining cut-off values of 1 or 2 for this sum., Results: Applying a cut-off value of 1, plasma free and total metanephrines and urinary fractionated metanephrines had similar sensitivities of 96% (95% confidence interval, 86-99%), 95% (85-99%), and 95% (84-99%) along with similar specificities of 89% (83-94%), 91% (84-95%), and 86% (80-91%). A cut-off of 2 for the sum of ratios over reference limit improves the specificity, and it can be used for a confirmation test based on another biomarker taken among the three biomarkers., Conclusion: All three metanephrine-based tests perform equivalently for diagnosing pheochromocytoma in the absence of renal insufficiency, and can be conveniently associated two by two for confirming/excluding tumor.