A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # |
24 Hour Timed Urine, Homovanillic Acid
Test CodeTUHVA
Quest Code
530
CPT Codes
83150
Preferred Specimen
10 mL urine: adjust a well-mixed urine sample with 6N HCl to maintain a ph below 3
Patient Preparation
It is preferable for the patient to be off medications for three days prior to collection. However, common antihypertensives (diuretics, ACE inhibitors, calcium channel blockers, alpha and beta blockers) cause minimal or no interference. Patient should avoid alcohol, coffee, tea, tobacco and strenuous exercise prior to collection.
Minimum Volume
5 mL
Other Acceptable Specimens
Urine without preservative
Instructions
10 mL urine - adjust a well-mixed urine sample with 6N HCl to maintain a pH below 3. Urine without preservative is acceptable if pH is below 6 and the sample is shipped frozen.
Record 24-hour urine volume on test request form and urine vial.
Record 24-hour urine volume on test request form and urine vial.
Transport Temperature
Room temperature
Specimen Stability
Room temperature: 10 days
Refrigerated: 14 days
Frozen: 90 days
Refrigerated: 14 days
Frozen: 90 days
Methodology
High Performance Liquid Chromatography (HPLC)
Setup Schedule
Night Sets up 2 days a week.
Report Available
Reports in 2 to 3 days.
Reference Range
3-8 years | 0.5-6.7 mg/24 h |
9-12 years | 1.1-6.8 mg/24 h |
13-17 years | 1.4-7.2 mg/24 h |
Adult | 1.6-7.5 mg/24 h |
Clinical Significance
Homovanillic acid (HVA) has been identified as the principal urinary metabolite of dopa and dopamine. HVA supports the diagnosis of neuroblastoma and malignant pheochromocytoma.
Performing Laboratory
Quest Diagnostics Nichols Institute
33608 Ortega Highway
San Juan Capistrano, CA 92675-2042