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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 # |
VMA (Vanillylmandelic Acid), 24-Hour Urine with Creatinine
Test CodeCPT Codes
82570, 84585
Includes
Preferred Specimen
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 (including use of nicotine patch), bananas, citrus fruits and strenuous exercise prior to collection.
Minimum Volume
Other Acceptable Specimens
Instructions
Record 24-hour urine volume and patient's age on test request form and on urine container.
Transport Temperature
Unpreserved urine: Frozen
Specimen Stability
Room temperature: 10 days
Refrigerated: 14 days
Frozen: 1 year
Unpreserved urine
Room temperature: Unacceptable
Refrigerated: Unacceptable
Frozen: 30 days
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Methodology
High Performance Liquid Chromatography (HPLC)
Setup Schedule
Reference Range
<3 Years | Not established | |||
3-8 Years | ≤2.3 mg/24 hours | |||
9-12 Years | ≤3.4 mg/24 hours | |||
13-17 Years | ≤3.9 mg/24 hours | |||
Adults | ≤6.0 mg/24 hours |
Creatinine, 24-Hour Urine
<3 Years | Not established | |||
3-8 Years | 0.10-0.80 g/24 h | |||
9-12 Years | 0.20-1.40 g/24 h | |||
13-17 Years | 0.40-1.90 g/24 h | |||
>17 Years | 0.50-2.15 g/24 h |
Clinical Significance
Urinary vanillylmandelic acid (VMA) concentration is useful in the biochemical diagnosis and monitoring of neuroblastomas [1].
Neuroblastomas occur predominantly in children and are the most common malignancy in those under 1 year old. Neuroblastomas are catecholamine-metabolizing tumors with limited ability to store and secrete catecholamines. Thus, catecholamine metabolites-including VMA and homovanillic acid (HVA)-are more reliable than catecholamines as biochemical markers for neuroblastomas [1]. VMA and HVA levels, usually measured simultaneously, can be elevated in neuroblastomas as well as other catecholamine-secreting tumors, such as pheochromocytoma [1]. In patients with familial dysautonomia (Riley-Day syndrome), a neurological disorder found mainly in individuals of Ashkenazi Jewish descent, VMA levels are generally elevated while HAV levels may be normal or decreased [2].
Urinary VMA and HVA levels may have limited accuracy for diagnosis of neuroblastomas with high-risk metastatic biology [1]. Therefore, dopamine levels in urine or serum have been proposed as an additional marker for diagnosis and monitoring of neuroblastomas [3].
The results of this test should be interpreted in the context of pertinent clinical and family history and physical examination findings.
References
1. Eisenhofer G. Monoamine-producing tumors. In: Rifai R, et al. eds. Tietz Textbook of Laboratory Medicine. 7th ed. Elsevier Inc; 2022.
2. Axelrod FB. Familial dysautonomia. Muscle Nerve. 2004;29(3):352-363.
3. Brodeur GM, et al. J Clin Oncol. 1993;11(8):1466-1477.