Lab Information Manual

Laboratory:

Clinical Biochemistry (METABOLIC)

Test Name:

VANILLYLMANDELIC ACID (VMA) - (U)

Test Code: VMA

Clinical Information:

Alternate Name(s): VMA (Vanillylmandelic Acid), 3-Methoxy-4-Hydroxymandelic Acid
Description: Homovanillic acid (HVA) and vanillylmandelic acid (VMA) are the preferred test for screening for neuroblastoma in a random urine specimen. Both tests should be performed.
Supporting neuroblastoma diagnosis & monitoring patients with a treated neuroblastoma.
Test Indications: Homovanillic acid (HVA) and vanillylmandelic acid (VMA) concentrations are elevated in more than 90% of patients with neuroblastoma; both tests should be performed. A positive test could be due to a genetic or nongenetic condition. Additional confirmatory testing is required.
A normal result does not exclude the presence of a catecholamine-secreting tumor.
Elevated HVA and VMA values are suggestive of a pheochromocytoma, but they are not diagnostic. For investigation of PHEOCHROMOCYTOMA in adults, the test FRACTIONATED METANEPHRINES (urine) should be ordered only.
This test is available on random or 24 h urine collection.
Recommendations: All patients receiving L-dopa should be identified to the laboratory when this test is ordered.
Patient preparation instructions: Administration of L-dopa may falsely increase homovanillic acid and vanillylmandelic acid results; it should be discontinued 24 hours prior to and during collection of the specimen.

Collection Devices:

Preferred Device:	1 - Urine Collection Container - 24 h Urine Collection Container - 24 h Manufacturer: VWR Scientific Products/Simport Plastics Catalogue #: CA73960-110
Alternate Device:	1 - Urine Collection Container, Random 100 mL Urine Collection Container, Random 100 mL Manufacturer: Starplex Scientific Inc. (Etobicoke, ON) Catalogue #: 3008-1 - (Fresh)

Specimen Required:

Adult: Volume 5-10 mL
Pediatric: Volume minimum 1.0 mL
Collection Information:
JA110-50-01B Random Urine Processing Flow Chart
JA110-50-01A 24 Hour Urine Processing Flow Chart
Specimen Stability:
Ambient: Acidified – 7 days
Refrigerated: Acidified – 4 weeks
Frozen: Acidified or not acidified – 6 months
- Samples MUST BE either Acidified OR Frozen within 4 hours of collection by the Collecting Site. Otherwise, the sample will be rejected.
- After acidifying, record pH on the requisition for registration (recording in clinical details in Delphic)
- If only frozen, record the pH before freezing.

Referral:

Shipping & Storage:
- Samples MUST BE either Acidified OR Frozen within 4 hours of collection by the Collecting Site. Otherwise, the sample will be rejected
- After acidifying, record pH on the requisition for registration (recording in clinical details in Delphic)
- If only frozen, record the pH before freezing.
- Store and ship accordingly.
- Submit aliquoted sample (24h urine collection)
Testing Laboratory (MB): Metabolic Lab (HSC)
If you have any questions, call Metabolic Lab at (204) 787-4530

Requisition:

_SH Urine Testing Requisition (R250-10-95)

Reference Values:

AGE	HVA	VMA
(Years)	(µmol/mmol creat.)	(µmol/mmol creat.)
<1	≤ 21.7	≤ 14.3
1	≤ 18.6	≤ 12.9
2–4	≤15.5	≤ 9.1
5-9	≤ 9.3	≤ 6.9
10-14	≤ 5.6	≤ 4.6
>14	≤ 6.2	≤ 4.0

Method of Analysis: Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)

Availability:

Within 10 Days

For urgent analysis, please communicate with the Metabolic Lab (204)787-4530 for arrangement.