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HelpTest Code METAF Metanephrines, Fractionated, 24 Hour, Urine
Reporting Name
Metanephrines, Fractionated, 24h, UUseful For
A first- and second-order screening test for the presumptive diagnosis of catecholamine-secreting pheochromocytomas and paragangliomas
Confirming positive plasma metanephrine results
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
UrineOrdering 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 Minimum Volume
3 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Urine | Refrigerated (preferred) | 28 days | |
| Ambient | 28 days | ||
| Frozen | 28 days |
Special Instructions
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
Day(s) Performed
Monday through Friday
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 |
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.
Clinical Reference
1. van Duinen N, Corssmit EPM, de Jong WHA, Brookman D, Kema IP, Romijn JA. Plasma levels of free metanephrines and 3-methoxytyramine indicate a higher number of biochemically active HNPGL than 24-h urinary excretion rates of catecholamines and metabolites. Eur J Endocrinol. 2013;169(3):377-382. doi:10.1530/EJE-13-0529
2. Pacak K, Linehan WM, Eisenhofer G, Walther MM, Goldstein DS. Recent advances in genetics, diagnosis, localization, and treatment of pheochromocytoma. Ann Intern Med. 2001;134(4):315-329
3. Sawka AM, Singh RJ, Young WF Jr. False positive biochemical testing for pheochromocytoma caused by surreptitious catecholamine addition to urine. Endocrinologist. 2001;11:421-423
4. Eisenhofer G, Grebe S, Cheung NKV. Monoamine-producing tumors. In: Rafai N, Horvath AR, Wittwer CT, eds. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 6th ed. Elsevier; 2018:1421
5. Shen Y, Cheng L. Biochemical diagnosis of pheochromocytoma and paraganglioma. In: Mariani-Costantini R, ed. Paraganglioma: A Multidisciplinary Approach. Codon Publications; 2019. doi:10.15586/paraganglioma.2019.ch2. Accessed: April 22, 2024. Available at: www.ncbi.nlm.nih.gov/books/NBK543224/
Report Available
3 to 5 daysMethod Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Forms
If not ordering electronically, complete, print, and send an Oncology Test Request (T729) with the specimen.