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Test Code Billings Clinic: 8565 Mayo: METAF Metanephrines, Fractionated, 24 Hour, Urine

Reporting Name

Metanephrines, Fractionated, 24h, U

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Useful For

A first- and second-order screening test for the presumptive diagnosis of catecholamine-secreting pheochromocytomas and paragangliomas

 

Confirming positive plasma metanephrine results

Method Name

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


Ordering Guidance


 



Necessary Information


24-Hour volume (in milliliters) is required.



Specimen Required


Patient Preparation: Tricyclic antidepressants, labetalol, and sotalol medications may elevate levels of metanephrines producing results that cannot be interpreted. If clinically feasible, it is optimal to discontinue these medications at least 1 week before collection. For advice on assessing the risk of removing patients from these medications and alternatives, consider consultation with a specialist in endocrinology or hypertension.

Supplies: Urine Tubes, 10 mL (T068)

Container/Tube: Plastic urine tube

Specimen Volume: 10 mL

Collection Instructions:

1. Add 10 g (pediatric: 3 g) of boric acid or 25 mL (pediatric: 15 mL) of 50% acetic acid as preservative at start of collection.

2. Collect urine for 24 hours.

Additional Information: See Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens for multiple collections.


Specimen Type

Urine

Specimen Minimum Volume

3 mL

Specimen Stability Information

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

Reject Due To

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

Reference Values

METANEPHRINE

Males

Normotensives

3-8 years: 29-92 mcg/24 h

9-12 years: 59-188 mcg/24 h

13-17 years: 69-221 mcg/24 h

≥18 years: 44-261 mcg/24 h

Reference values have not been established for patients that are younger than 36 months.

 

Hypertensives: <400 mcg/24 h

Females

Normotensives

3-8 years: 18-144 mcg/24 h

9-12 years: 43-122 mcg/24 h

13-17 years: 33-185 mcg/24 h

≥18 years: 30-180 mcg/24 h

Reference values have not been established for patients that are younger than 36 months.

 

Hypertensives: <400 mcg/24 h

 

NORMETANEPHRINE

Males

Normotensives

3-8 years: 34-169 mcg/24 h

9-12 years: 84-422 mcg/24 h

13-17 years: 91-456 mcg/24 h

18-29 years: 103-390 mcg/24 h

30-39 years: 111-419 mcg/24 h

40-49 years: 119-451 mcg/24 h

50-59 years: 128-484 mcg/24 h

60-69 years: 138-521 mcg/24 h

≥70 years: 148-560 mcg/24 h

Reference values have not been established for patients that are younger than 36 months.

 

Hypertensives: <900 mcg/24 h

 

Females

Normotensives

3-8 years: 29-145 mcg/24 h

9-12 years: 55-277 mcg/24 h

13-17 years: 57-286 mcg/24 h

18-29 years: 103-390 mcg/24 h

30-39 years: 111-419 mcg/24 h

40-49 years: 119-451 mcg/24 h

50-59 years: 128-484 mcg/24 h

60-69 years: 138-521 mcg/24 h

≥70 years: 148-560 mcg/24 h

Reference values have not been established for patients that are younger than 36 months.

 

Hypertensives: <900 mcg/24 h

 

TOTAL METANEPHRINE

Males

Normotensives

3-8 years: 47-223 mcg/24 h

9-12 years: 201-528 mcg/24 h

13-17 years: 120-603 mcg/24 h

18-29 years: 190-583 mcg/24 h

30-39 years: 200-614 mcg/24 h

40-49 years: 211-646 mcg/24 h

50-59 years: 222-680 mcg/24 h

60-69 years: 233-716 mcg/24 h

≥70 years: 246-753 mcg/24 h

Reference values have not been established for patients that are younger than 36 months.

 

Hypertensives: <1,300 mcg/24 h

 

Females

Normotensives

3-8 years: 57-210 mcg/24 h

9-12 years: 107-394 mcg/24 h

13-17 years: 113-414 mcg/24 h

18-29 years: 142-510 mcg/24 h

30-39 years: 149-535 mcg/24 h

40-49 years: 156-561 mcg/24 h

50-59 years: 164-555 mcg/24 h

60-69 years: 171-616 mcg/24 h

≥70 years: 180-646 mcg/24 h

Reference values have not been established for patients that are younger than 36 months.

 

Hypertensives: <1,300 mcg/24 h

 

For International System of Units (SI) conversion for Reference Values, see www.mayocliniclabs.com/order-tests/si-unit-conversion.html

Interpretation

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

 

Total urine metanephrine levels of 1300 mcg/24 h and lower can be detected in non-pheochromocytoma hypertensive patients.

 

Further clinical investigation (eg, radiographic studies) is warranted in patients whose total urinary metanephrine levels are above 1300 mcg/24 h (approximately 2 times the upper limit of normal). For patients with total urinary metanephrine levels below 1300 mcg/24 h, further investigations may also be indicated if either the normetanephrine or the metanephrine fraction of the total metanephrines exceed their respective upper limit for hypertensive patients. Finally, repeat testing or further investigations may occasionally be indicated in patients with urinary metanephrine levels below the hypertensive cutoff, or even normal levels, if there is a very high clinical index of suspicion.

Day(s) Performed

Monday through Friday

Report Available

3 to 5 days

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

83835

LOINC Code Information

Test ID Test Order Name Order LOINC Value
METAF Metanephrines, Fractionated, 24h, U 104632-5

 

Result ID Test Result Name Result LOINC Value
8552 Metanephrine, U 104629-1
21545 Normetanephrine, U 104631-7
83006 Total Metanephrines, U 104630-9
TM50 Collection Duration (h) 13362-9
VL48 Volume (mL) 3167-4
2434 Comment 48767-8

Forms

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

Urine Preservative Collection Options

Note: The addition of preservative must occur prior to the start of the collection or application of temperature controls must occur during collection.

Ambient (no additive)

No

Refrigerate (no additive)

OK

Frozen (no additive)

OK

50% Acetic Acid

Preferred

Boric Acid

Preferred

Diazolidinyl Urea

No

6M Hydrochloric Acid

OK

6M Nitric Acid

No

Sodium Carbonate

OK

Thymol

No

Toluene

OK