5-HIAA (5-Hydroxyindoleacetic Acid), 24-Hour Urine (without Creatinine) (HIAA5)

Message
Patient should avoid food high in indoles: avocado, banana, tomato, plum, walnut, pineapple, and eggplant. Patient should also avoid tobacco, tea and coffee for three days prior to specimen collection.

Test Code
LAB3138

Quest Code
523

Alias/See Also
HIAA5

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 urine with 25 mL 6N HCl to maintain a pH <3. Urine without preservative is acceptable if pH is <6 and sample is shipped frozen. Keep urine refrigerated during collection if preservatives are not used. Record 24-hour urine volume on test requisition and the urine vial. Record patient's age on test request form and urine vial.

Transport Container
24 hr urine container

Transport Temperature
Room temperature; frozen if unpreserved

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?)
pH >3.0 and received unfrozen

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
Monday-friday

Report Available
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

2-10 Years	≤8.0 mg/24 h
>10 Years	≤6.0 mg/24 h

Clinical Significance
Values above 10 mg/24 hrs 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, Bronchodilators, Clonidine, Digoxin, Isoniazid, L-Dopa, Labetelol, Methyldopa, Monoamine Oxidase Inhibitors, Nitroglycerin, Sympathomimetic Amines, Phenobarbital, Phenothiazines, Phentolamine, Reserprine, Salicylates, Tricyclic Antidepressants.

Performing Laboratory

Quest Diagnostics Nichols Institute-Chantilly VA

14225 Newbrook Drive

Chantilly, VA 20151-2228

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.