5-HIAA (5-Hydroxyindoleacetic Acid), 24-Hour Urine [523X]

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

Test Code
523

CPT Codes
83497

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

Preferred Specimen
10 mL of 24-hour urine with 25 mL 6N HCl collected in a 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
Unpreserved 24-hour urine with pH <6

Instructions
COLLECT URINE WITH 25 ML 6N HCL TO MAINTAIN A PH BELOW 3.  
URINE WITHOUT PRESERVATIVE IS ACCEPTABLE IF PH IS BELOW 6  
AND SAMPLE IS SHIPPED FROZEN. KEEP URINE REFRIGERATED DURING
COLLECTION IF PRESERVATIVES ARE NOT USED. RECORD 24 HOUR   
URINE VOLUME ON TEST REQUEST FORM AND THE URINE VIAL.      

Transport Temperature
Preserved urine: Room temperature
Unpreserved urine: Frozen

Specimen Stability
Room temperature: 7 days
Refrigerated: 30 days
Frozen: 30 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
pH >3.0 • 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 the FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Setup Schedule
Set up: Mon-Fri a.m.; Report available: 2 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
14225 Newbrook Drive
Chantilly, VA 20153



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.