Clinical background:
Clinical utility
Homovanillic acid (HVA) [and Vanillylmandelic acid (VMA)] is measured in urine for screening, diagnosis and monitoring children for neuroblastoma.
Clinical significance
Neuroblastoma is a neoplastic disease of infants and early childhood and is the third most common malignant cancer tumours in paediatric patients. Approximately 80% are found in children under 5 years of age. Elevated values of homovanillic acid (HVA, a metaboloite of dopamine) and VMA (a metabolite of metadrenalines), may be suggestive of the presence of neuroblastoma. HVA and VMA can be used for the diagnosis and follow up treatment of neuroblastoma. Early studies showed that the long term survival rate of these patients could be readily diagnosed using VMA/HVA ratios.
Specimen container paediatric:
White universal container
Specimen container adult:
White universal container
Minimum volume paediatric:
1 – 10 mL urine
Minimum volume adult:
1 – 10 mL urine
Special requirements:
Laboratory processing:
Do
- Upon receipt in laboratory, adjust pH to 3.0 to 6.0, and remove an aliquot for analysis.
- Store urine aliquot at 4°C prior to transport and analysis.
Do not
- over-acidify to pH <3.0
Sample stability:
Once pH has been adjusted to 3.0 to 3.5, samples are stable at 4°C for up to 10 days.
For long-term storage, store samples at –20°C.
Transport requirements:
For external laboratories:
Once pH has been adjusted to 3.0 to 6.0, transport urine aliquot at ambient temperature.
Freq Analysis:
1 x weekly
Quality Assurance:
UK NEQAS
Interpretation:
Homovanillic acid (HVA) and/or VMA concentrations are elevated in over 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 urinary HVA values are suggestive of a deficiency of dopamine beta-hydrolase, a neuroblastoma, a pheochromocytoma, or may reflect administration of L-dopa.
Decreased urinary HVA values may suggest monamine oxidase-A deficiency.
Reference ranges:
| Age | HVA (µmol/mmol creatinine) |
| 0 to 6 months | <28 |
| 6 to 9 months | <25 |
| 9 to 12 months | <23 |
| 1-2 years | <20 |
| 2 to 3 years | <16 |
| 3 to 4 years | <13 |
| 4 to 5 years | <11 |
| 5 to 7 years | <10 |
| 7 to 10 years | <9 |
| 10 years to Adult | <8.5 |
Factors affecting result:
Administration of L-dopa may falsely increase HVA results. Patients receiving L-dopa should stop taking it for 24 hours before and during the collection.
All patients receiving L-dopa should be identified to the laboratory when VMA and HVA tests are ordered.
Other Info:
Urine HVA analysis is performed by LC-MS/MS.