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Test ID: HVAR    
Homovanillic Acid (HVA), Random, Urine

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Useful For Suggests clinical disorders or settings where the test may be helpful

Screening children for catecholamine-secreting tumors

 

Monitoring neuroblastoma treatment

 

Screening patients with possible inborn errors of catecholamine metabolism

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

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; monamine 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.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

<1 year: <35.0 mg/g creatinine

1 year: <23.0 mg/g creatinine

2-4 years: <13.5 mg/g creatinine

5-9 years: <9.0 mg/g creatinine

10-14 years: <12.0 mg/g creatinine

> or =15 years (adults): < or =10.0 mg/g creatinine

Interpretation Provides information to assist in interpretation of the test results

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 monamine oxidase-A deficiency.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

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.

Clinical Reference Provides recommendations for further in-depth reading of a clinical nature

1. Hyland K, Biaggioni I, Elpeleg OH, et al: Disorders of neurotransmitter metabolism. In Physician's Guide to the Laboratory Diagnosis of Metabolic Disease, Chapman and Hall Medical. Edited by N Blau, M Duran, ME Blaskovics. London, UK, 1996, pp 79-98

2. Hyland K: Presentation, diagnosis, and treatment of the disorders of monoamine neurotransmitter metabolism. Sem Perinatol 1999;23:194-203

3. Strenger V, Kerbl R, Dornbusch HJ, et al: Diagnostic and prognostic impact of urinary catecholamines in neuroblastoma patients. Pediatr Blood Cancer 2007 May;48(5):504-509