Vanillylmandelic Acid

Label Mnemonic:	VMA24
Epic code:	LAB7449
Downtime form:	A-1a Doctor/Provider Orders - Pathology Core and Specialty Care Nursery

Commercial Mailout Laboratory
6240-8 RCP
356-8593

Specimen(s):

24 hr Urine More information

Specimen Instructions:

Refrigerate during 24 hr collection in plastic container. Refrigeration is the preferred method of preservation. Collection containers available from pharmacy.

All four tests may be done on same collection.

Abstain from medications for 72 hours prior to collection.

Collection Medium:

Urine - 24 hour/timed plastic urine container

Minimum:

Preferred Minimum: 4 mL from a well-mixed 24 hr urine collection. Random urine is also accepted at reference lab. Refrigerate during collection and submission.

Absolute Minimum: 1 mL from a well-mixed 24 hr urine collection. Random urine is also accepted at reference lab. Refrigerate during collection and submission.

Turn Around Time:

1-4 days upon receipt at reference laboratory

Reference Range:

Components           Age                 Ref. Interval

Vanillylmandelic     18 years and older  0.0-7.0 mg/d
  Acid - per 24 hr

Vanillylmandelic     The VMA-to-creatinine ratio will be reported when 
  Acid - Ratio       the patient is under 18 years or the  urine volume
  to CRT             is less than 400 mL/24 hours.

Vanillylmandelic     0-2 years           0-27 mg/g CRT
  Acid - Ratio       3-5 years           0-13 mg/g CRT
  to CRT             6-17 years          0-9 mg/g CRT
                     18 years and older  0-6 mg/g CRT

Creatinine Urine - 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:

Vanillylmandelic acid (VMA) results are expressed as a ratio to creatinine excretion (mg/g cr). VMA mass per day (mg/d) is not reported on specimens from patients younger than 18 years of age, for random specimens, urine collection periods other than 24 hours, or for urine volumes less than 400 mL/d. No reference interval is available for results reported in units of mg/L.

Comments:

If screening for Neuroblastoma, the following tests are suggested: 
CAT24 (Catecholamines, Fractionated; Dopamine is included), HVA24 
(Homovanillic Acid), MET24 (Metanephrines), VMA24 (Vanillylmandelic 
Acid).

VMA, Catecholamines, HVA, and Metanephrines may be done on same 
collection.  All five tests may be done on same collection.

Moderately elevated VMA (vanillylmandelic acid) can be caused by a 
variety of factors such as essential hypertension, intense anxiety, 
intense physical exercise, and numerous drug interactions (including 
some over-the-counter medications and herbal products). 

Medications that may interfere with catecholamines and their 
metabolites include amphetamines and amphetamine-like compounds, 
appetite suppressants, bromocriptine, buspirone, caffeine, 
chlorpromazine, clonidine, disulfiram, diuretics (in doses sufficient 
to deplete sodium), epinephrine, glucagon, guanethidine, histamine, 
hydrazine derivatives, imipramine, levodopa (L-dopa, Sinemet®), 
lithium, MAO inhibitors, melatonin, methyldopa (Aldomet®), 
morphine, nitroglycerin, nose drops, propafenone (Rythmol), 
radiographic agents, rauwolfia alkaloids (Reserpine), tricyclic 
antidepressants, and vasodilators.  The effects of some drugs on 
catecholamine metabolite results may not be predictable.

Methodology:

Quantitative High Performance Liquid Chromatography - Tandem Mass Spectrometry

CPT Code:

84585

See also:
Catecholamines, Fractionated, 24 hr Urine
Homovanillic Acid, 24 hr Urine
Metanephrines Total, 24 hr Urine

See Additional Information:
Urine Tests Requiring Preservatives, Refrigeration or Special Containers