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

Test Code

METNF

Alias/See Also

LAB3260

CPT Codes
<p>83835</p>

Includes

Metanephrine, Free
Normetanephrine, Free
Total, Free (MN + NMN)

Preferred Specimen

Patient Preparation: 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.

Specimen Type: Plasma EDTA

Collection Container/Type: Lavender top (EDTA)

Submission Container/Tube: Plastic vial

Specimen Volume: 2.5 mL

Collection Instructions:

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.

Patient Preparation
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.

Minimum Volume

1.5 mL

Instructions

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.

Transport Container

Plastic screw-cap vial

Transport Temperature

Refrigerated (cold packs)

Specimen Stability

Room temperature: 4 hours

Refrigerated: 14 days

Frozen: 14 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Heparinized plasma • Serum • CSF • Urine

Methodology

Chromatography/Tandem Mass Spectrometry

This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

FDA Status
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Setup Schedule

Set up: Mon-Sat; Report available: 2 days

Report Available

2 days

Limitations

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

Reference Range

Metanephrine, Free	≤57 pg/mL
Normetanephrine, Free	≤148 pg/mL
Total, Free (MN + NMN)	≤205 pg/mL

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., 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.

Performing Laboratory
Quest Diagnostics Nichols Institute 14225 Newbrook Drive Chantilly, VA 20153

Last Updated: February 23, 2012

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.