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Test Code PMET Metanephrines, Fractionated, Free, Plasma

Reporting Name

Metanephrines, Fract., Free, P

Useful For

Screening test for presumptive diagnosis of catecholamine-secreting pheochromocytomas or paragangliomas

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Plasma EDTA


Specimen 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 days

Reject 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)