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HVA (Homovanillic Acid) Neuroblastoma Profile
Homovanillic Acid Rnd U (HVAR)
Homovanillic Acid, Random, Urine
Screening children for catecholamine-secreting tumors with a random urine collection when requesting homovanillic acid only
Monitoring neuroblastoma treatment
Screening patients with possible inborn errors of catecholamine metabolism
1. Collect a random urine specimen.
2. Adjust the random urine pH to a level between 1 and 5 by adding 50% acetic acid dropwise and checking the pH. (Special Chemistry department staff will adjust pH prior to sending to Mayo.
3. Patient's age is required.
4. All patients receiving L-dopa should be identified to Mayo Clinic Laboratories when this test is ordered.
5. Bactrim may interfere with detection of the analyte. All patients taking Bactrim should be identified to Mayo Clinic Laboratories when this test is ordered.
Administration of L-dopa may falsely increase homovanillic acid (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 vanillylmandelic acid (VMA) and HVA tests are ordered.
Bactrim may interfere with detection of the analyte. All patients taking Bactrim should be identified to the laboratory when VMA and HVA tests are ordered.
Homovanillic acid (HVA) and other catecholamine metabolites (vanillylmandelic acid: VMA and dopamine) are typically elevated in patients with catecholamine-secreting tumors (eg, neuroblastoma, pheochromocytoma, and other neural crest tumors). HVA and VMA levels may also be useful in monitoring patients who have been treated as a result of the above-mentioned tumors. HVA levels may also be altered in disorders of catecholamine metabolism; monoamine oxidase-A deficiency can cause decreased urinary HVA values, while a deficiency of dopamine beta-hydrolase (the enzyme that converts dopamine to norepinephrine) can cause elevated urinary HVA 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
> or =15 years (adults): <8.0 mg/g creatinine
Vanillylmandelic acid and/or homovanillic acid (HVA) 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 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 monoamine oxidase-A deficiency.