Metanephrines, Fractionated, Free, LC/MS/MS, Plasma
Test Summary
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., antihypertensive agents, alcohol, cocaine) and other pre-analytical factors (e.g., stress, severe congestive heart failure, myocardial infarction) that influence release of catecholamines and metanephrines.
Aliases
- N/A
Specimen Collection
Special Instructions
N/A
Preferred Specimen
2.5 mL EDTA plasma
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 degrees 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.
Storage
Plastic screw-cap vial
Transport Temperature
Refrigerated (cold packs)
Specimen Stability
- Plasma:
- Room Temperature: 4 HOURS
- Refrigerated: 14 DAYS
- Frozen: 14 DAYS
Limitations
False-positive results have been observed in patients with either chronic kidney disease or hypertension.
Other Acceptable Specimens
N/A
Unacceptable Specimens
Heparinized Plasma, Serum, CSF, Urine
Order Code
METANF
EPIC (Premier) Code
LAB3304
Includes
Metanephrine, Free
Normetanephrine, Free
Total, Free (MN + NMN)
Normetanephrine, Free
Total, Free (MN + NMN)
CPT Code
- 83835
Billing Code
- 670169
CPT Statement
Methodology
Chromatography/Mass Spectrometry
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 the U.S. Food and Drug Administration. The FDA has determined that such clearance or approval is not necessary. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.
Physician Attestation of Informed Consent
N/A
Testing Laboratory
Quest Diagnostics Nichols Institute
14225 Newbrook Drive
Chantilly VA, 20153
14225 Newbrook Drive
Chantilly VA, 20153
Department
Reference Testing
Reference Range
| Metanephrine, Free | ≤57 pg/mL |
| Normetanephrine, Free | ≤148 pg/mL |
| Total, Free (MN + NMN) | ≤205 pg/mL |
Setup Schedule / Expected Turnaround Time
Monday - Saturday; Report available: 2 days
Specimen Collection
Special Instructions
N/A
Preferred Specimen
2.5 mL EDTA plasma
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 degrees 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.
Storage
Plastic screw-cap vial
Transport Temperature
Refrigerated (cold packs)
Specimen Stability
- Plasma:
- Room Temperature: 4 HOURS
- Refrigerated: 14 DAYS
- Frozen: 14 DAYS
Limitations
False-positive results have been observed in patients with either chronic kidney disease or hypertension.
Other Acceptable Specimens
N/A
Unacceptable Specimens
Heparinized Plasma, Serum, CSF, Urine
Result Information
Methodology
Chromatography/Mass Spectrometry
Testing Laboratory
N/A
Reference Range
| Metanephrine, Free | ≤57 pg/mL |
| Normetanephrine, Free | ≤148 pg/mL |
| Total, Free (MN + NMN) | ≤205 pg/mL |
Setup Schedule / Expected Turnaround Time
Monday - Saturday; Report available: 2 days