Sign in →

Test Code LAB9690 Metanephrines, Fractionated, Random, Urine

Additional Codes

METRN


Specimen Required


Patient Preparation:

1. For at least 48 hours prior to test, patient should avoid use of cold medicines, nose drops, and nasal sprays.

2. Patients taking tricyclic antidepressants and labetalol and sotalol (beta blockers) may have falsely elevated levels of metanephrines. If medically feasible, for at least 1 week before specimen collection, the patient should not take these medications.

Supplies: Urine Tubes, 10 mL (T068)

Collection Container/Tube: Clean, plastic urine collection container

Submission Container/Tube: Plastic, 10 mL urine tube

Specimen Volume: 10 mL

Collection Instructions:

1. Collect a random urine specimen.

2. No preservative.


Secondary ID

609696

Useful For

A second-order screening test for the presumptive diagnosis of pheochromocytoma in patients with non-episodic hypertension

 

Confirming positive plasma metanephrine results in patients with non-episodic hypertension

Profile Information

Test ID Reporting Name Available Separately Always Performed
METAU Metanephrines, Fractionated, U No Yes
CRETR Creatinine, Random, U Yes, (Order RCTUR) Yes

Method Name

METAU: Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)

CRETR: Enzymatic Colorimetric Assay

Specimen Type

Urine

Specimen Minimum Volume

3 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Urine Refrigerated (preferred) 28 days
  Frozen  28 days
  Ambient  14 days

Reject Due To

  All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Reference Values

METANEPHRINE/CREATININE

Normotensives

0-2 years: 82-418 mcg/g creatinine

3-8 years: 65-332 mcg/g creatinine

9-12 years: 41-209 mcg/g creatinine

13-17 years: 30-154 mcg/g creatinine

≥18 years: 29-158 mcg/g creatinine

 

NORMETANEPHRINE/CREATININE

Males

Normotensives

0-2 years: 121-946 mcg/g creatinine

3-8 years: 92-718 mcg/g creatinine

9-12 years: 53-413 mcg/g creatinine

13-17 years: 37-286 mcg/g creatinine

18-29 years: 53-190 mcg/g creatinine

30-39 years: 60-216 mcg/g creatinine

40-49 years: 69-247 mcg/g creatinine

50-59 years: 78-282 mcg/g creatinine

60-69 years: 89-322 mcg/g creatinine

≥70 years: 102-367 mcg/g creatinine

 

Females

Normotensives

0-2 years: 121-946 mcg/g creatinine

3-8 years: 92-718 mcg/g creatinine

9-12 years: 53-413 mcg/g creatinine

13-17 years: 37-286 mcg/g creatinine

18-29 years: 81-330 mcg/g creatinine

30-39 years: 93-379 mcg/g creatinine

40-49 years: 107-436 mcg/g creatinine

50-59 years: 122-500 mcg/g creatinine

60-69 years: 141-574 mcg/g creatinine

≥70 years: 161-659 mcg/g creatinine

 

TOTAL METANEPHRINE/CREATININE

Males

Normotensives

0-2 years: 241-1,272 mcg/g creatinine

3-8 years: 186-980 mcg/g creatinine

9-12 years: 110-582 mcg/g creatinine

13-17 years: 78-412 mcg/g creatinine

18-29 years: 96-286 mcg/g creatinine

30-39 years: 106-316 mcg/g creatinine

40-49 years: 117-349 mcg/g creatinine

50-59 years: 130-386 mcg/g creatinine

60-69 years: 143-427 mcg/g creatinine

≥70 years: 159-472 mcg/g creatinine

 

Females

Normotensives

0-2 years: 241-1,272 mcg/g creatinine

3-8 years: 186-980 mcg/g creatinine

9-12 years: 110-582 mcg/g creatinine

13-17 years: 78-412 mcg/g creatinine

18-29 years: 131-467 mcg/g creatinine

30-39 years: 147-523 mcg/g creatinine

40-49 years: 164-585 mcg/g creatinine

50-59 years: 184-655 mcg/g creatinine

60-69 years: 206-733 mcg/g creatinine

≥70 years: 230-821 mcg/g creatinine

Interpretation

Increased metanephrine and normetanephrine levels are found in patients with pheochromocytoma and tumors derived from neural crest cells.

 

Increased urine metanephrines can be detected in non-pheochromocytoma hypertensive patients; quantification may help distinguish these patients from those with tumor-induced symptoms.

Method Description

Urinary metanephrines are determined by liquid chromatography tandem mass spectrometry (LC-MS/MS). Urinary metanephrines occur largely in conjugated form. After urine samples are acidified and hydrolyzed in a heat block, metanephrine and normetanephrine are extracted from the specimens utilizing extraction cartridges. The metanephrine, normetanephrine, and 3-methoxytyramine (3MT) are eluted from the cartridge and analyzed by LC/MS/MS using multiple reaction monitoring in positive mode. Deuterated metanephrine (d3-metanephrine), deuterated normetanephrine (d3-normetanephrine), and deuterated 3MT (d4-3MT) are added prior to the hydrolysis as internal standards. The metanephrine, normetanephrine, and 3-MT concentrations are quantified using ratios of the peak areas to deuterium labeled internal standards by LC-MS/MS.(Unpublished Mayo method)

 

Creatinine:

The enzymatic method is based on the determination of sarcosine from creatinine with the aid of creatininase, creatinase, and sarcosine oxidase. The liberated hydrogen peroxide is measured via a modified Trinder reaction using a colorimetric indicator. Optimization of the buffer system and the colorimetric indicator enables the creatinine concentration to be quantified both precisely and specifically.(Package insert: Creatinine plus ver 2. Roche Diagnostics; V15.0, 03/2019)

Day(s) Performed

Monday through Friday

Report Available

3 to 5 days

Specimen Retention Time

2 weeks

Performing Laboratory

Mayo Clinic Laboratories in Rochester

CPT Code Information

83835

82570

LOINC Code Information

Test ID Test Order Name Order LOINC Value
METRN Metanephrines, Fract., Random, U 68317-7

 

Result ID Test Result Name Result LOINC Value
21546 Metanephrine/Creatinine 9645-3
CRETR Creatinine, Random, U 2161-8
21547 Normetanephrine/Creatinine 13783-6
21548 Total Metanephrine/Creatinine 13771-1

Forms

If not ordering electronically, complete, print, and send a Oncology Test Request (T729) with the specimen.