Metanephrines
Order Code: MET24
Epic Lab Code: LAB7451
Order Form: A-1a General Lab or Epic Req
Commercial Mail-out Laboratory
6240 RCP
356-3527
Specimen:
Urine
Collection Medium:
Urine - 24 hour/timed plastic urine container
Minimum:
Preferred Minimum: 4 mL of a well-mixed 24 hr urine
Absolute Minimum: 1.5 mL of a well-mixed of 24 hr collection.
Abstain from medications for 72 hours prior to collection.
Rejection Criteria:
Room temperature specimens.
Specimen Instructions:
Refrigerate 24-hour specimen during collection. Adequate refrigeration is the most important aspect of specimen preservation.
Analytic Time:
1-3 days upon receipt at reference laboratory.
Reference Range:
Components Reference Interval (18 years and older) Metanephrine 152-1775 nmol/d Normetanephrine 273-3548 nmol/d The metanephrines-to-creatinine ratios will be reported when the patient is under 18 years, or the urine volume is less than 400 mL/24 hours. Metanephrine 0-3 months 0-402 μmol/mol crt 4-6 months 0-373 μmol/mol crt 7-11 months 0-373 μmol/mol crt 1 year 0-304 μmol/mol crt 2-5 years 0-287 μmol/mol crt 6-17 years 0-184 μmol/mol crt 18 years and older 0-172 μmol/mol crt Normetanephrine 0-3 months 0-2098 μmol/mol crt 4-6 months 0-1357 μmol/mol crt 7-11 months 0-679 μmol/mol crt 1 year 0-802 μmol/mol crt 2-5 years 0-376 μmol/mol crt 6-17 years 0-278 μmol/mol crt 18 years and older 0-247 μmol/mol crt Creatinine (24 hr) Male 3-8 years 140-700 mg/d 9-12 years 300-1300 mg/d 13-17 years 500-2300 mg/d 18-50 years 1000-2500 mg/d 51-80 years 800-2100 mg/d 81 years and older 600-2000 mg/d Female 3-8 years 140-700 mg/d 9-12 years 300-1300 mg/d 13-17 years 400-1600 mg/d 18-50 years 700-1600 mg/d 51-80 years 500-1400 mg/d 81 years and older 400-1300 mg/d
Interpretive Data:
Ratios to creatinine may be useful for evaluation of patients younger than 18 years of age, when the urine collection is random or other than 24 hours, or the urine volume is less than 400 mL/24 hours.

Moles per day (nmol or μmol) calculations are not reported when the urine collection is random or other than 24 hours, or the urine volume is less than 400 mL/24 hours.

Smaller increases in normetanephrine and/or Metanephrine concentrations (less than two times the upper reference limit) usually are the result of physiological stimuli, drugs, or improper specimen collection. Significant elevation of one or both metanephrines (3 or more times the upper reference limit) is associated with an increased probability of a neuroendocrine tumor.
Comments:
If screening for Neuroblastoma, the following tests are suggested: CAT24 (Catecholamines, Fractionated; Dopamine is included), HVA24 (Homovanillic Acid), MET24 (Metanephrines), VMA24 (Vanillylmandelic Acid). 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, Urine
Homovanillic Acid (HVA), Urine
Vanillylmandelic Acid (VMA), Urine
 
See Additional Information:
Urine Tests Requiring Preservatives, Refrigeration or Special Containers