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
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.
Per 24h calculations are provided to aid interpretation for collections with a duration of 24 hours and an average daily urine volume. For specimens with notable deviations in collection time or volume, ratios of analytes to a corresponding urine creatinine concentration may assist in result interpretation.
This test was developed and its performance characteristics determined by ARUP Laboratories. It has not been cleared or approved by the US Food and Drug Administration. This test was performed in a CLIA certified laboratory and is intended for clinical purposes.
Laboratory Developed Test (LDT)
|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|