Topic
Metanephrine
About: Metanephrine is a research topic. Over the lifetime, 703 publications have been published within this topic receiving 22377 citations. The topic is also known as: metadrenaline & 3-O-Methyl-Adrenaline.
Papers published on a yearly basis
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Papers
TL;DR: Plasma free metanephrines provide the best test for excluding or confirming pheochromocytoma and should be the test of first choice for diagnosis of the tumor.
Abstract: ContextDiagnosis of pheochromocytoma depends on biochemical evidence of catecholamine
production by the tumor. However, the best test to establish the diagnosis
has not been determined.ObjectiveTo determine the biochemical test or combination of tests that provides
the best method for diagnosis of pheochromocytoma.Design, Setting, and ParticipantsMulticenter cohort study of patients tested for pheochromocytoma at
4 referral centers between 1994 and 2001. The analysis included 214 patients
in whom the diagnosis of pheochromocytoma was confirmed and 644 patients who
were determined to not have the tumor.Main Outcome MeasuresTest sensitivity and specificity, receiver operating characteristic
curves, and positive and negative predictive values at different pretest prevalences
using plasma free metanephrines, plasma catecholamines, urinary catecholamines,
urinary total and fractionated metanephrines, and urinary vanillylmandelic
acid.ResultsSensitivities of plasma free metanephrines (99% [95% confidence interval
{CI}, 96%-100%]) and urinary fractionated metanephrines (97% [95% CI, 92%-99%])
were higher than those for plasma catecholamines (84% [95% CI, 78%-89%]),
urinary catecholamines (86% [95% CI, 80%-91%]), urinary total metanephrines
(77% [95% CI, 68%-85%]), and urinary vanillylmandelic acid (64% [95% CI, 55%-71%]).
Specificity was highest for urinary vanillylmandelic acid (95% [95% CI, 93%-97%])
and urinary total metanephrines (93% [95% CI, 89%-97%]); intermediate for
plasma free metanephrines (89% [95% CI, 87%-92%]), urinary catecholamines
(88% [95% CI, 85%-91%]), and plasma catecholamines (81% [95% CI, 78%-84%]);
and lowest for urinary fractionated metanephrines (69% [95% CI, 64%-72%]).
Sensitivity and specificity values at different upper reference limits were
highest for plasma free metanephrines using receiver operating characteristic
curves. Combining different tests did not improve the diagnostic yield beyond
that of a single test of plasma free metanephrines.ConclusionPlasma free metanephrines provide the best test for excluding or confirming
pheochromocytoma and should be the test of first choice for diagnosis of the
tumor.
1,169 citations
TL;DR: Advances in genetic mutation analysis have greatly improved identification of patients with familial pheochromocytoma, allowing detection of tumors at an early stage, often before typical signs and symptoms occur and highlighting inadequacies of commonly used diagnostic tests.
Abstract: Pheochromocytoma is a rare but important tumor of chromaffin cells that is frequently considered in the evaluation of hypertension, arrhythmias, or panic disorder and in the follow-up of patients with particular genetic diseases. This report provides an update about the genetics, neurochemical diagnosis, localization by imaging, and surgical management of pheochromocytoma. Specific mutations of the RET proto-oncogene cause familial predisposition to pheochromocytoma in multiple endocrine neoplasia type II, and mutations in the von Hippel-Lindau tumor suppressor gene cause familial disposition to pheochromocytoma in von Hippel-Lindau disease. Recent findings demonstrating extraordinarily high sensitivity of plasma levels of metanephrines for detecting pheochromocytoma have led to an algorithm for clinical diagnostic steps. Nuclear imaging approaches, such as(123) I-metaiodobenzylguanidine scintigraphy and 6-[(18) F]fluorodopamine positron emission tomography, enhance both diagnosis and localization of the tumor, as described in an algorithm for patients with positive biochemical test results. Since pheochromocytoma is often benign, surgical resection by laparoscopic adrenalectomy can be curative. Areas requiring further work include determining appropriate follow-up of patients with familial pheochromocytoma, elucidating the bases for phenotypic differences, improving both specificity and sensitivity of biochemical tests, optimizing cost-effectiveness of diagnostic imaging, and testing the risk for tumor recurrence after partial adrenalectomy.
624 citations
TL;DR: In patients with suspected pheochromocytoma and positive biochemical results, false-positive elevations due to medications should first be eliminated and patterns of biochemical test results and responses of plasma normetanephrine to clonidine can then help distinguish true- from false- positive results.
Abstract: Measurements of plasma normetanephrine and metanephrine provide a highly sensitive test for diagnosis of pheochromocytoma, but false-positive results remain a problem. We therefore assessed medication-associated false-positive results and use of supplementary tests, including plasma normetanephrine responses to clonidine, to distinguish true- from false-positive results. The study included 208 patients with pheochromocytoma and 648 patients in whom pheochromocytoma was excluded. Clonidine-suppression tests were carried out in 48 patients with and 49 patients without the tumor. Tricyclic antidepressants and phenoxybenzamine accounted for 41% of false-positive elevations of plasma normetanephrine and 44-45% those of plasma and urinary norepinephrine. High plasma normetanephrine to norepinephrine or metanephrine to epinephrine ratios were strongly predictive of pheochromocytoma. Lack of decrease and elevated plasma levels of norepinephrine or normetanephrine after clonidine also confirmed pheochromocytoma with high specificity. However, 16 of 48 patients with pheochromocytoma had normal levels or decreases of norepinephrine after clonidine. In contrast, plasma normetanephrine remained elevated in all but 2 patients, indicating more reliable diagnosis using normetanephrine than norepinephrine responses to clonidine. Thus, in patients with suspected pheochromocytoma and positive biochemical results, false-positive elevations due to medications should first be eliminated. Patterns of biochemical test results and responses of plasma normetanephrine to clonidine can then help distinguish true- from false-positive results.
485 citations
TL;DR: The detection of pheochromocytoma requires a high degree of clinical alertness, especially in patients with familial tumors, elevation of blood pressure, either continuous or continuous for long periods of time.
Abstract: THE early diagnosis of pheochromocytoma is important, not only because it offers the possibility of curing hypertension but also because unrecognized pheochromocytoma is a potentially lethal condition. Hypertensive crisis or shock or both leading to death have been precipitated by drugs, anesthetic agents, parturition, or surgery for an unrelated condition. Moreover, 8 to 10 per cent of the tumors are malignant. The detection of pheochromocytoma requires a high degree of clinical alertness. Although rare cases have been reported in which the tumor was not associated with hypertension, especially in patients with familial tumors, elevation of blood pressure, either continuous or . . .
451 citations
TL;DR: Human plasma contains several catechols, including the catecholamines norepinephrine, epinephrine, and dopamine, their precursor, l-3,4-dihydroxyphenylalanine (l-DOPA), and their deaminated metabolites, dihydroxyphensylglycol, the main neuronal metabolite of nore Pinephrine,
Abstract: Human plasma contains several catechols, including the catecholamines norepinephrine, epinephrine, and dopamine, their precursor, L-3,4-dihydroxyphenylalanine (L-DOPA), and their deaminated metabolites, dihydroxyphenylglycol, the main neuronal metabolite of norepinephrine, and dihydroxyphenylacetic acid, a deaminated metabolite of dopamine. Products of metabolism of catechols include 3-methoxytyrosine (from L-DOPA), homovanillic acid and dopamine sulfate (from dopamine), normetanephrine, vanillylmandelic acid, and methoxyhydroxyphenylglycol (from norepinephrine), and metanephrine (from epinephrine). Plasma levels of catechols and their metabolites have related but distinct sources and therefore reflect different functions of catecholamine systems. This article provides an update about plasma levels of catechols and their metabolites and the relevance of those levels to some issues in human health and disease.
440 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2025 | 10 |
| 2024 | 18 |
| 2023 | 37 |
| 2022 | 57 |
| 2021 | 33 |
| 2020 | 26 |