Metanephrines, Free Plasma
Test Mnemonic
PMETAN
CPT Codes
- 83835 - QTY (1)
Aliases
- Fractionated plasma Metanephrines
- Free Metanephrines
- Plasma Normetanephrines
Includes
- Plasma metanephrine
- Plasma normetanephrine
Performing Laboratory
Cleveland Clinic Laboratories
FDA Category
Laboratory Developed Test
Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 1.5 mL | Plasma | EDTA (Lavender) | Place specimen on ice after draw. | Frozen | Centrifuge and remove plasma from cells within 1 hour of collection. Freeze plasma immediately after separation from cells. |
Minimum Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 0.7 mL |
Stability
| Environmental Condition | Description |
|---|---|
| Ambient | 4 hours |
| Refrigerated | 3 days |
| Frozen | 1 year |
Days Performed
2 days per week
Turnaround Time
1 - 5 days
Methodology
| Name | Description |
|---|---|
| Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) |
Reference Range
| Metanephrine, Free plasma | |||||
|---|---|---|---|---|---|
| Sex | Age From | Age To | Type | Range | Range Unit |
| Hypertensive Adult >= 18 yrs old: 12-72 pg/mL | Normotensive Adult >= 18 yrs old: 12-67 pg/mL | Normotensive children < 18 yrs old: 10-95 pg/mL | |||
| Normetanephrine, Free plasma | |||||
| Sex | Age From | Age To | Type | Range | Range Unit |
| Hypertensive adult >= 18 yrs old: 24-145 pg/mL | Normotensive adult >= 18 yrs old: 18-101 pg/mL | Normotensive children < 18 yrs old: 22-83 pg/mL |
Special Info
Avoid strenuous exercise for 3 days prior to collection. Discontinue epinephrine and epinephrine-like drugs at least 3 days before collection if possible. Allow patient to be seated in a relaxed position for 10-15 minutes before collection.
Clinical Info
Plasma metanephrine levels can be useful in the diagnosis of pheochromocytoma or paraganglioma. The measurement of plasma free metanephrines is considered the most sensitive and specific biomarkers for the detection of pheochromocytoma or paraganglioma. Methyldopa may cause false elevation of normetanephrine levels in this assay. If patient is on methyldopa, interpret results with caution.
Clinical Limitation
Plasma Free Metanephrine test performed by Liquid Chromatography Tandem Mass Spectrometry (LC/MS/MS). Results obtained with different methods or kits cannot be used interchangeably.