First-line test in suspected pheochromocytoma.
Quantitative High Performance Liquid Chromatography-Tandem Mass Spectrometry
If possible, abstain from medications for 72 hours prior to collection.
24-hour or random urine. Refrigerate 24-hour specimen during collection.
Thoroughly mix entire collection (24-hour or Random) in one container. Transfer a 4 mL aliquot to an ARUP Standard Transport Tube. (Min: 2.5 mL) A pH lower than 2 can cause assay interference. Record total volume and collection time interval on transport tube and test request form.
Specimen preservation can be extended to 1 month refrigerated by performing one of the following:
Option 1: Transfer a 4 mL aliquot to an ARUP Standard Transport Tube. (Min: 2.5 mL) Adjust pH to 2.0-4.0 with 6M HCl.
Option 2: Transfer a 4 mL aliquot to an ARUP Standard Transport Tube containing 20 mg sulfamic acid (ARUP Supply #48098), available online through eSupply using ARUP Connect™or contact ARUP Client Services at (800) 522-2787. (Min: 2.5 mL)
Refrigerated. Also acceptable: Frozen.
Specimens preserved with boric acid or acetic acid.
Ambient: Unacceptable; Refrigerated: 2 weeks (unpreserved), 1 month (preserved); Frozen: 1 month
|Reference Intervals for 24 Hour Calculations (24-Hour Urine)|
|Metanephrine, Urine - per 24h||
|Normetanephrine, Urine - per 24h||
|0020473||Creatinine, Urine - per 24h||
|Reference Intervals for Ratio-to-Creatinine (CRT) Calculations (Random Urine)|
18 years and older
|0-700 µg/g crt
0-650 µg/g crt
0-650 µg/g crt
0-530 µg/g crt
0-500 µg/g crt
0-320 µg/g crt
0-300 µg/g crt
18 years and older
|0-3400 µg/g crt
0-2200 µg/g crt
0-1100 µg/g crt
0-1300 µg/g crt
0-610 µg/g crt
0-450 µg/g crt
0-400 µg/g crt
The optimal specimen for this testing is a 24-hour urine collection. Per-day calculations are not reported for patients younger than 7 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 (if 18 years of age or older) or greater than 5000 mL (all ages). 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 400 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.
Compliance Statement B: For laboratory developed tests not using a RUO kit, and for FDA approved, cleared or 510(k) exempt assays with alterations. This test was developed and its performance characteristics determined by ARUP Laboratories. The U. S. Food and Drug Administration has not approved or cleared this test; however, FDA clearance or approval is not currently required for clinical use. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions.
|Component Test Code*||Component Chart Name||LOINC|
|0020207||Creatinine, Urine - per volume||2161-8|
|0020208||Creatinine, Urine - per 24h||2162-6|
|0080228||Metanephrines, Urine Interpretation||49283-5|
|2007997||Metanephrine, Urine - per volume||21019-5|
|2007998||Normetanephrine, Urine - per volume||21422-1|
|2007999||Metanephrine, Urine - per 24h||19049-6|
|2008000||Metanephrine, Urine - ratio to CRT||35644-4|
|2008001||Normetanephrine, Urine - per 24h||2671-6|
|2008002||Normetanephrine, Urine - ratio to CRT||44342-4|