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To view specimen requirements and codes please select your laboratory:
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Metanephrines, Fractionated, Free, LC/MS/MS, Plasma
Metanephrine, Normetanephrine, and Total Metanephrine
Patient should avoid alcohol, coffee, tea, tobacco and strenuous exercise prior to collection. Overnight fasting is preferred. Patients should be relaxed in either a supine or upright position before blood is drawn.
2.5 mL plasma collected in an EDTA (lavender-top) tube
Draw specimen in a pre-chilled EDTA lavender-top Vacutainer®. The whole blood sample should be kept on wet ice until centrifuged (preferably at 4° C) to separate the plasma within 2 hours of venipuncture. After centrifugation, the plasma should be transferred to a plastic, leak-proof vial and immediately refrigerated.
Refrigerated (cold packs)
Room temperature: 4 hours
Refrigerated: 14 days
Frozen: 14 days
Heparinized plasma • Serum • CSF • Urine
Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS)
Quest Diagnostics Nichols Institute
33608 Ortega Highway
San Juan Capistrano, CA 92690-6130
Set up: Mon-Fri; Report available: 3-5 days
False-positive results have been observed in patients with either chronic kidney disease or hypertension.
Metanephrine, Free: < OR = 57 pg/mL
Normetanephrine, Free: < OR = 148
Total, Free (MN + NMN): < OR = 205 pg/mL
Elevations > 4-fold upper reference range: strongly suggestive of a
pheochromocytoma(1). Elevations >1 - 4-fold upper reference range:
significant but not diagnostic, may be due to medications or stress. Suggest
running 24 hr urine fractionated metanephrines and serum Chromogranin A for confirmation.
Normetanephrine (NM) and metanephrine (MN) are the extra-neuronal catechol-o-methyl transferase (COMT) metabolites of the catecholamines norepinephrine and epinephrine, respectively. Measurement of plasma metanephrines is more sensitive (but may be less specific) than measurement of catecholamines for the detection of pheochromocytoma. Proper interpretation of results requires awareness of recent medication/drug history (e.g., antyhypertensive agents, alcohol, cocaine) and other pre-analytical factors (e.g., stress, severe congestive heart failure, myocardial infarction) that influence release of catecholamines and metanephrines.
Reference ranges are provided as general guidance only. To interpret test results use the reference range in the laboratory report.
(The CPT codes provided are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.)
* The tests listed by specialist are a select group of tests offered. For a complete list of Quest Diagnostics tests, please refer to our Directory of Services.