5-Hydroxyindoleacetic Acid (5-HIAA), 24-Hour Urine without Creatinine

Test Code

5HIAA

Alias/See Also

523

CPT Codes
83497

Includes

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

Preferred Specimen

10 mL aliquot from a 24-hour urine that has been preserved with 25 mL 6N HCl, collected in a plastic 24-hour urine container

Patient Preparation
Patient should avoid food high in indoles: avocado, banana, tomato, plum, walnut, pineapple, and eggplant

Minimum Volume

5 mL

Other Acceptable Specimens

Aliquot from a 24-hour urine, unpreserved with a pH ≤6, collected in a plastic 24-hour urine container

Instructions

Collect 24-hour urine with 25 mL 6N HCl to maintain a pH ≤3. If no preservative is used, specimen must be stored refrigerated during collection but shipped frozen and pH must be ≤6.
Record 24-hour urine volume and patient's age on test request form and urine container.

Transport Temperature

Preserved: Room temperature
Unpreserved: Frozen

Specimen Stability

Preserved urine
Room temperature: 7 days
Refrigerated: 30 days
Frozen: 30 days

Unpreserved urine
Room temperature: Unacceptable
Refrigerated: Unacceptable
Frozen: 30 days

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

Preserved urine received refrigerated with a pH >3 • Unpreserved urine received frozen with pH >6

Methodology
High Performance Liquid Chromatography (HPLC)

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

Set up: Tue-Sat; Report Available: 1-3 days

Limitations

Patients with renal disease may display falsely decreased results. Urinary 5-HIAA is increased in patients with malabsorption disorders who also display a larger concentration of urinary tryptophan metabolites. Urinary 5-HIAA is increased in patients with intestinal obstruction and with some noncarcinoid islet cell tumors. Carcinoid syndrome may not cause elevated results, especially if the patient does not have diarrhea.

Reference Range

<2 Years	Not established
2-10 Years	≤8.0 mg/24 h
>10 Years	≤6.0 mg/24 h

Clinical Significance

Values above 10 mg/24-hours occur in carcinoid syndrome. Slight elevations also occur in nontropical sprue and after reserpine administration. Drugs which can interfere with testing due to physiologic response: Acetaminophen, alpha and beta blockers, atenolol, bromocriptine, broncholdilators, clonidine, digoxin, isoniazid, L-dopa, labetalol, methyldopa, monoamine oxidase inhibitors, nitroglycerin, sympathomimetic amines, phenobarbital, phenothiazines, phentolamine, reserpine, salicylates, tricyclic antidepressants.

Performing Laboratory
Quest Diagnostics Nichols Institute
33608 Ortega Highway
San Juan Capistrano, CA 92690-6130

Last Updated: May 17, 2024

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.