5-Hydroxyindoleacetic Acid (HIAA), Urine
Also known as: HIAA
Use
The 5-Hydroxyindoleacetic Acid (HIAA) urine test is primarily used for the diagnosis of carcinoid tumors and to monitor disease progression. Carcinoid tumors often lead to elevated levels of 5-HIAA, a metabolite of serotonin, in urine. Elevated 5-HIAA levels can also indicate other conditions such as malabsorption syndromes or the consumption of serotonin-rich foods. The test helps to differentiate between these conditions and monitor patients for treatment efficacy and disease progression.
Special Instructions
Patients should avoid foods rich in serotonin such as bananas, avocados, and walnuts, and abstain from medications including both over-the-counter drugs and herbal remedies 72 hours prior to the test. During the urine collection period, these restrictions must continue to ensure accurate results. Dietary and medication intake can influence 5-HIAA levels, leading to potential diagnostic inaccuracies.
Limitations
The test results can be influenced by improper specimen collection, consumption of serotonin-containing foods or dietary supplements, interference from various drugs, and certain health conditions like malabsorption syndromes. A significant spike in 5-HIAA levels, far exceeding the upper reference limit, is suggestive of carcinoid tumors. However, elevated levels may not exclusively indicate this condition and should be interpreted in the context of clinical findings and other diagnostic procedures. The ratio to creatinine excretion can aid in interpretation for collections that adhere to the 24-hour collection duration.
New York Approved
Methodology
Mass Spectrometry
Biomarkers
LOINC Codes
- 35674-1
- 2162-6
- 44909-0
- 1695-6
- 31203-3
- 44288-9
- 19153-6
- 30211-7
Result Turnaround Time
1-5 days
Related Documents
For more information, please review the documents below
Specimen
Urine
Volume
4 mL
Minimum Volume
1 mL
Container
ARUP standard transport tube
Collection Instructions
Transfer 4 mL aliquot from a well-mixed 24-hour collection to an ARUP standard transport tube. Record total volume and collection time interval on transport tube and test request form.
Patient Preparation
Patients should avoid medications, over-the-counter drugs, and herbal remedies for 72 hours prior to the test. Foods rich in serotonin must also be avoided.
Causes for Rejection
Any sample except urine.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | Unacceptable |
| Refrigerated | 1 week |
| Frozen | 2 months |