Dopamine, Urine

Test Code

14763

CPT Codes
82542

Includes

CPT code 81050 may be added at an additional charge for volume measurement

Preferred Specimen

10 mL 24-hour urine with 25 mL 6N HCl collected in a 24-hour urine container

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

Unpreserved 24-hour urine

Instructions

Urine without preservative is acceptable if pH is below 6 and the sample is shipped frozen

Transport Temperature

Room temperature

Specimen Stability

Room temperature: 7 days
Refrigerated: 30 days
Frozen: 49 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

pH >3.0 and received unfrozen

Methodology
Ultra Performance Liquid Chromatography

FDA Status
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Setup Schedule

A.M. Sets up 5 days a week.

Clinical Significance

Measurement of dopamine levels in urine or blood in addition to urinary vanillylmandelic acid (VMA) and homovanillic acid (HVA) levels may aid in the biochemical diagnosis and monitoring of neuroblastomas [1]. This test may also be useful in evaluating dopamine-secreting pheochromocytomas and paragangliomas (PPGLs) [2].

Neuroblastomas occur predominantly in children and are the most common malignancy under 1 year old. Neuroblastomas are catecholamine-metabolizing tumors with limited ability to store and secrete catecholamines. Thus, catecholamine metabolites (including VMA and HVA) are more reliable than catecholamines as biochemical markers for neuroblastomas [1]. However, urinary VMA and HVA levels may have limited accuracy for diagnosis of neuroblastomas with high-risk metastatic biology [1]. Because poor prognosis is associated with immaturity of catecholamine metabolism, dopamine levels in urine or blood have been proposed as an additional marker to aid in diagnosis and monitoring of neuroblastomas [3].

Most PPGLs secrete catecholamines, but the relative amounts of dopamine, norepinephrine, and epinephrine vary widely. Measurements of plasma free or urinary fractionated metanephrines (ie, the O-methylated catecholamine metabolites) are recommended by the Endocrine Society for the initial biochemical testing of PPGLs [4]. In patients with high clinical suspicion but normal blood pressure and normal levels of metanephrines, measurement of dopamine and its metabolites (HVA and methoxytyramine) may help diagnose PPGLs that predominantly secrete dopamine [2].

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. Jain A, et al. Pediatr Nephrol. 2020;35(4):581-594.
3. Brodeur GM, et al. J Clin Oncol. 1993;11(8):1466-1477.
4. Lenders JW, et al. J Clin Endocrinol Metab. 2014;99(6):1915-1942

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.