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Test Code U24 HVA Homovanillic Acid (HVA), 24 Hour, Urine

Reporting Name

Homovanillic Acid (HVA), 24 Hr, U

Useful For

Screening children for catecholamine-secreting tumors with a 24-hour urine collection when requesting homovanillic acid only

 

Monitoring neuroblastoma treatment

 

Screening patients with possible inborn errors of catecholamine metabolism


Necessary Information


1. Collection duration and urine volume are required.

2. Patient's age is required.



Specimen Required


Container/Tube: Plastic, 10-mL urine tube (T068)

Specimen Volume: 5 mL

Collection Instructions:

1. Collect a 24-hour urine specimen.

2. Add 25 mL of 50% acetic acid as preservative at start of collection. If specimen is refrigerated during collection, preservative may be added up to 12 hours after collection. Use 15 mL of 50% acetic acid for children less than 5 years old. This preservative is intended to achieve a pH of between approximately 1 and 5. If necessary, adjust urine pH to 1 to 5 with 50% acetic or HCI acid.

Additional Information:

1. Administration of L-dopa may falsely increase homovanillic acid results; it should be discontinued 24 hours prior to and during collection of specimen.

2. The sensitivity of this test is greater on a 24-hour specimen than on a random specimen.

3. See Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens in Special Instructions for multiple collections.

4. Bactrim may interfere with detection of the analyte. All patients taking Bactrim should be identified to the laboratory when this test is ordered.


Specimen Type

Urine

Specimen Minimum Volume

2 mL

Specimen Stability Information

Specimen Type Temperature Time
Urine Refrigerated (preferred) 28 days
  Frozen  180 days

Day(s) and Time(s) Performed

Monday through Friday; 8 a.m.

Performing Laboratory

Mayo Medical Laboratories in Rochester

Method Name

Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

Method Description

Homovanillic acid (HVA) is measured by solid-phase extraction (SPE) of a 1-mL aliquot of urine. A known amount of stable isotope-labeled HVA internal standard (IS) is added to each urine specimen prior to SPE. HVA and IS are eluted from the SPE column with methanol. The methanol is evaporated and the HVA and IS are redissolved in liquid chromatography tandem-mass spectrometry (LC-MS/MS) mobile phase. A portion of this prepared extract is injected onto a LC column that separates HVA and IS from the bulk of any remaining specimen matrix. The HVA and IS are measured by mass spectrometry/tandem-mass spectrometry using the selected reaction monitoring mode. HVA is quantified using the ratio to IS versus urine calibrators.(Magera MJ, Stoor A, Helgeson JK, et al: Determination of homovanillic acid in urine by stable isotope dilution and electrospray tandem mass spectrometry. Clin Chim Acta 2001;306:35-41)

Reference Values

<1 year: <35.0 mg/g creatinine

1 year: <30.0 mg/g creatinine

2-4 years: <25.0 mg/g creatinine

5-9 years: <15.0 mg/g creatinine

10-14 years: <9.0 mg/g creatinine

≥15 years (adults): <8 mg/24 hours

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information

83150

LOINC Code Information

Test ID Test Order Name Order LOINC Value
HVA Homovanillic Acid (HVA), 24 Hr, U 13760-4

 

Result ID Test Result Name Result LOINC Value
3572 Homovanillic Acid, Adult (>14 yr) 2436-4
3573 Homovanillic Acid, Child (<15 yr) 13760-4
TM39 Collection Duration 13362-9
VL37 Urine Volume 3167-4

Reject Due To

Hemolysis

NA

Lipemia

NA

Icterus

NA

Other

NA

Urine Preservative Collection Options

Ambient

No

Refrigerated

No

Frozen

No

6N HCl

Yes

50% Acetic Acid

Preferred

Na2CO3

No

Toluene

No

6N HNO3

No

Boric Acid

No

Thymol

No

Forms

If not ordering electronically, complete, print, and send an Oncology Test Request Form (T729) with the specimen (http://www.mayomedicallaboratories.com/it-mmfiles/oncology-request-form.pdf)