5-Hydroxyindoleacetic Acid (HIAA), Urine

Also known as: HIAA

Clinical Use

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

Not provided.

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.

Test Details

New York Approved

Methodology

Mass Spectrometry

Biomarkers

5-Hydroxyindoleacetic Acid (5-HIAA)

Analyte

5-HIAA Urine - ratio to CRT

Concentration / Level • Quantitative (Continuous) (e.g., copies/mL, % expression)

5-HIAA Urine - per 24h

Concentration / Level • Quantitative (Continuous) (e.g., copies/mL, % expression)

LOINC Codes

Result Codes

35674-1 - Creat ?Tm Ur-mCnc
2162-6 - Creat 24h Ur-mRate
44909-0 - 5HIAA & Creatinine Ur-Imp
1695-6 - 5OH-indoleacetate 24h Ur-mRate
31203-3 - 5OH-indoleacetate 24h Ur-mCnc
44288-9 - 5OH-indoleacetate/Creat 24h Ur
19153-6 - Specimen vol ?Tm Ur
30211-7 - Specimen collect Time Spec

Result Turnaround Time

1-5 days

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.