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HelpTest Code PMET Metanephrines, Fractionated, Free, Plasma
Reporting Name
Metanephrines, Fract., Free, PUseful For
Screening test for presumptive diagnosis of catecholamine-secreting pheochromocytomas or paragangliomas
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
Plasma EDTASpecimen Required
Patient Preparation: Use of an Epi-pen within last 7 days may produce inaccurate results.
Collection Container/Tube: Lavender top (EDTA)
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions: Spin down within 2 hours of draw. Plasma must be separated from red blood cells within 2 hours of collection.
Specimen Minimum Volume
0.3 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Plasma EDTA | Frozen (preferred) | 14 days | |
| Refrigerated | 7 days |
Reference Values
METANEPHRINE, FREE
<0.50 nmol/L
NORMETANEPHRINE, FREE
<0.90 nmol/L
Day(s) and Time(s) Performed
Monday through Saturday; 1 p.m.
Not reported on Sunday
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.CPT Code Information
83835
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| PMET | Metanephrines, Fract., Free, P | 57772-6 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 10140 | Normetanephrine, Free | 40851-8 |
| 10139 | Metanephrine, Free | 49700-8 |
Clinical Reference
1. Eisenhofer G: Free or total metanephrines for diagnosis of pheochromocytoma: what is the difference? Clin Chem 2001 June;47(6):988-989
2. Lenders JW, Pacek K, Walther MM, et al: Biochemical diagnosis of pheochromocytoma: which test is best? JAMA 2002 Mar 20;287(11):1427-1434
3. Sawka AM, Jaeschke R, Singh RJ, Young WF Jr: A comparison of biochemical tests for pheochromocytoma: measurement of fractionated plasma metanephrines compared to the combination of 24-hour urinary metanephrines and catecholamines. J Clin Endocrinol Metab 2003 Feb;88(2):553-558
4. Algeciras-Schimnich A, Preissner CM, Young WF Jr, et al: Plasma chromogranin A or urine fractionated metanephrines follow-up testing improves the diagnostic accuracy of plasma fractionated metanephrines for pheochromocytoma. J Clin Endocrinol Metab Oct 16, 2007;doi:doi:10.1210/jc.2007-1354
Method Description
Free metanephrine and normetanephrine are extracted from plasma using solid phase extraction. The concentrated eluate is analyzed using liquid chromatography-tandem mass spectometry (LC-MS/MS) and quantified using stable isotope-labeled internal standards, d(3)-metanephrine and d(3)-normetanephrine.(Taylor RL, Singh RJ: Validation of liquid chromatography-tandem mass spectrometry method for analysis of urinary conjugated metanephrine and normetanephrine for screening of pheochromocytoma. Clin Chem 2002 Mar;48[3]:533-539)
Analytic Time
2 daysReject Due To
| Gross hemolysis | Reject |
| Gross lipemia | OK |
| Gross icterus | OK |
Method Name
Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
Forms
If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:
-General Request (T239)
-Oncology Test Request (T729)