Homovanillic Acid, 24 Hour, Urine
Use
Homovanillic acid (HVA) measurement in urine is used for screening children for catecholamine‑secreting tumors, such as neuroblastoma, pheochromocytoma, and other neural crest tumors, and monitoring those who have had treatment. Additionally, measurement of HVA is useful for diagnosing disorders of catecholamine metabolism, such as monoamine oxidase‑A deficiency and dopamine beta‑hydroxylase deficiency, which result in altered urinary HVA values.
Special Instructions
Treatment with L‑dopa can impact test results and should be discontinued 24 hours prior to collection. Bactrim can also impact test results and should be noted at the time of collection. Patient’s age, collection duration, and urine volume are required. When not ordering electronically, complete and send an Oncology Test Request (T729) with the specimen.
Limitations
A positive result requires confirmatory testing; a normal result does not exclude the presence of a catecholamine‑secreting tumor. Elevated HVA may reflect dopamine beta‑hydroxylase deficiency, neuroblastoma, pheochromocytoma, or L‑dopa administration. Decreased urinary HVA may suggest monoamine oxidase‑A deficiency.
New York Approved
Methodology
Mass Spectrometry (LC‑MS/MS)
Biomarkers
LOINC Codes
- 13362-9
- 13760-4
- 3167-4
- 2436-4
- 13760-4
Result Turnaround Time
2-4 days
Related Documents
For more information, please review the documents below
Specimen
Urine
Volume
5 mL
Minimum Volume
2 mL
Container
Plastic, 10-mL urine tube
Collection Instructions
Collect a 24‑hour urine specimen. Add 25 mL of 50% acetic acid as preservative at start; use 15 mL for children <5 years. If refrigerated, preservative may be added up to 12 hours after collection. If necessary, adjust pH to 1–5 with 50% acetic acid or hydrochloric acid.
Patient Preparation
Discontinue L‑dopa 24 hours prior to and during collection; identify patients taking Bactrim.
Storage Instructions
Refrigerate (preferred) during transport (up to 28 days); or freeze (up to 180 days).
Stability Requirements
| Temperature | Period |
|---|---|
| Refrigerated | 28 days |
| Frozen | 180 days |