Metanephrines, Plasma

Test Code

PMET

Alias/See Also

Metanephrines, Fractionated, Free, LC/MS/MS, Plasma

Quest Code
19548

CPT Codes
83835

Includes

Metanephrine
Normetanephrine
Total Metanephrine

Preferred Specimen

2.5 mL plasma collected in an EDTA (lavender-top) tube, transferred to a plastic screw-cap vial

Minimum Volume

1.5 mL plasma

Patient Preparation
Overnight fasting is preferred.
Patient should avoid alcohol, coffee, tea, tobacco and strenuous exercise before collection.

Instructions

Draw specimen in two pre-chilled EDTA (lavender-top) tubes. The whole blood sample should be kept on wet ice until centrifuged. Separate the plasma within 2 hours of venipuncture. After centrifugation, the plasma should immediately be transferred to a plastic, leak-proof vial. Refrigerate.

Transport Temperature

Refrigerated

Specimen Stability

Room temperature: 4 hours
Refrigerated: 14 days
Frozen: 14 days

Methodology
Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS)

Setup Schedule

Monday-Saturday a.m.

Report Available

2 days

Limitations

False-positive results have been observed in patients with either chronic kidney disease or hypertension.

Clinical Significance

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., antihypersensitive agents, alcohol, cocaine) and other pre-analytical factors (e.g., stress, severe congestive heart failure, myocardial infarction) that influence release of catecholamines and metanephrines.

Performing Laboratory
Quest Diagnostics Nichols Institute
Chantilly, VA

The CPT Codes provided in this document 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 payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.