Normetanephrine ELISA (Urine)

The Normetanephrine ELISA is now available as an IVDR compliant product.

Intended Purpose

Enzyme immunoassay for the quantitative determination of normetanephrine in human urine. This test serves as an aid of diagnosis as well as a monitoring tool for the presumptive diagnosis and therapy follow-up of catecholamine-secreting pheochromocytomas and paragangliomas. Patient population includes adults suspected to be affected by neuroendocrine tumors. Pre-test in case of genetic predisposition (e.g. Von-Hippel-disease, and multiple endocrine neoplasia type 2) is advised.
The test kit is intended for professional use only. The test kit is not for self-testing. The Normetanephrine ELISA is NOT intended for near patient testing. The test kit is intended for manual use and can be adapted to open ELISA processors.

Clinical significance

The term metanephrines include metanephrine, normetanephrine and 3-methoxytyramin, which are the metabolites of catecholamines (adrenalin, noradrenalin and dopamine). Normetanephrine is naturally excreted into urine and certain tissues. At least 90 % of metanephrine and up to 40 % of normetanephrine are formed from metabolism of epinephrine and norepinephrine within the adrenals before release of these catecholamines into the circulation.[1] In several diseases, e.g. pheochromocytomas, catecholamines and their metabolites metanephrine and normetanephrine are secreted in increasing amounts and associated with different clinical symptoms like severe hypertension palpitations and headache and are therefore applied for diagnostic purposes.[2] Diagnosis and the follow-up of tumor diseases of the nervous system are of special importance.[3] This applies primarily to catecholamine-secreting tumors such as pheochromocytoma and paragangliomas.[2] Pheochromocytomas are rare tumors with 10 % being malignant [4]. They are neoplasms generally characterized by the autonomous production of catecholamines.[5] These catecholamine-producing tumors arise form chromaffin cells of the adrenal medulla or extra-adrenal paraganglionic tissue.[6] The inappropriate concentration of catecholamines may results in sustained or intermittent severe hypertension. Typical clinical symptoms include headaches, sweating and tachycardia.
The localization of the tumor, either in the adrenal medulla or extra-adrenal, can be found by measuring urinary metanephrines.[7]
Furthermore, a genetic screen should be applied due to heredity predispositions like von Hippel- Lindau disease or family members of patients with multiple endocrine neoplasia type 2 (MEN 2). [1] After the adrenal masses are surgically removed the diagnosis is postoperatively confirmed by histological examinations as well as by clinical follow-up.[5] Patients are re-examined after the surgery as well and metanephrine levels are checked.[8] Most pheochromocytomas are discovered in people aged 20 - 50 years but the tumor can develop at any age (Mayo Clinic, 2018). Metanephrines can be found in blood and urine and can be measured as free metanephrines or in a conjugated form after hydrolysis. Metanephrines in urine are commonly measured after an acid hydrolysis step that converts the large proportion of sulfate-conjugated metabolites from the free metabolite. For measuring total fractionated metanephrines, acid hydrolysis or enzymatic treatment is necessary before the assay. According to Lenders and colleagues urinary metanephrines may be more specific.[10]

For concrete data please consult the Instruction for Use in the download box on the top right side.