Metanephrines Total

Label Mnemonic:	METUR
Epic code:	LAB7401
Downtime form:	A-1a Doctor/Provider Orders - Pathology Core and Specialty Care Nursery

Commercial Mailout Laboratory
6240-8 RCP
356-8593

Specimen(s):

Random Urine

Collection Medium:

Yellow top round bottom tube (no additive)

Minimum:

Preferred Minimum: 4 mL random urine
Absolute Minimum: 2.5 mL random urine

Abstain from medications for 72 hours prior to collection.

Rejection Criteria:

Specimens preserved with boric acid or acetic acid.

Turn Around Time:

1-4 days upon receipt at reference laboratory

Reference Range:

Reference Intervals for Ratio-to-Creatinine (CRT) 
Calculations (Random Urine)

Components      Age                 Ref. Interval

Metanephrine    0-3 months          0-700 μg/g crt
                4-6 months          0-650 μg/g crt
                7-11 months         0-650 μg/g crt
                1 year              0-530 μg/g crt
                2-5 years           0-500 μg/g crt
                6-17 years          0-320 μg/g crt
                18 years and older  0-300 μg/g crt 

Normetanephrine 0-3 months          0-3400 μg/g crt
                4-6 months          0-2200 μg/g crt
                7-11 months         0-1100 μg/g crt
                1 year              0-1300 μg/g crt
                2-5 years           0-610 μg/g crt
                6-17 years          0-450 μg/g crt
                18 years and older  0-400 μg/g crt

Interpretive Data:

The optimal specimen for this testing is a 24-hour urine collection. Per-day calculations are not reported for patients younger than 18 years of age and for the following specimen types: a random collection, a collection with duration of less than 20 hours, a collection with duration of greater than 28 hours, or a collection with total volume less than 400 mL. Ratios to creatinine may be useful for these evaluations.

Smaller increases in metanephrine and/or normetanephrine concentrations (less than two times the upper reference limit) usually are the result of physiological stimuli, drugs, or improper specimen collection. Essential hypertension is often associated with slight elevations (metanephrine less than 700 μg/d and normetanephrine less than 900 μg/d). Elevated concentrations may be due to intense physical activity, life-threatening illness, and drug interferences.

Significant elevation of one or both metanephrines (three or more times the upper reference limit) is associated with an increased probability of a neuroendocrine tumor.

Comments:

Secreting neuroendocrine tumors typically are associated with metanephrine or normetanephrine concentrations several times higher than the upper reference intervals. Other reasons for elevated concentrations include intense physical activity, life-threatening illness, and drug interferences. Essential hypertension is often associated with slight elevations (metanephrine less than 3500 nmol/day and normetanephrine less than 4900 nmol/day). Other reasons for slight and moderate elevations include emotional and physical stress and improper specimen collection.

Methodology:

Quantitative High Performance Liquid Chromatography-Tandem Mass Spectrometry

CPT Code:

83835

See also:
Catecholamines, Fractionated, Random Urine
Homovanillic Acid, Random Urine
Vanillylmandelic Acid, Random Urine

See Additional Information:
Urine Tests Requiring no Preservatives