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Test ID HIAA 5-Hydroxyindoleacetic Acid (5-HIAA), 24 Hour, Urine

Useful For

Biochemical diagnosis and monitoring of intestinal carcinoid syndrome

Method Name

Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

Reporting Name

5-Hydroxyindoleacetic Acid, U

Specimen Type

Urine

Container/Tube: Plastic, 10-mL urine tube (T068)

Specimen Volume: 5 mL

Collection Instructions:

1. Collect a 24-hour urine specimen.

2. Add 25 mL of 50% acetic acid as preservative at start of collection. Use 15 mL of 50% acetic acid for children <5 years old.

3. For 48 hours before patients start their urine collection and during the 24 hours they collect urine:

Limit the following to 1 serving per day:

-Fruits

-Vegetables

-Nuts

-Caffeinated beverages or foods

 

Do not take the following over-the-counter (OTC) medications:

-Acetaminophen (Tylenol or generic versions)

-Aspirin

-Antihistamines

-Cough syrups

-Cold and flu medications

 

Some prescription medications could interfere with test results. The ordering provider should decide if any medications should be stopped and when they should be restarted.

 

Additional Information:

1. 24-hour volume is required.

2. See Urine Preservatives in Special Instructions for multiple collections.

Forms: If not ordering electronically, complete, print, and send an Oncology Test Request Form (T729) with the specimen

(http://www.mayomedicallaboratories.com/it-mmfiles/oncology-request-form.pdf)

 

Urine Preservative Collection Options

Ambient

No

Refrigerated

Yes

Frozen

Yes

6N HCl

Yes (30 mL)

50% Acetic Acid

Preferred

Na2CO3

Yes (5 g)

Toluene

Yes (30 mL)

6N HNO3

Yes (15 mL)

Boric Acid

Yes (10 g)

Thymol

Yes (10%)

 

Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time
Urine Refrigerated (preferred) 56 days
  Frozen  365 days

Clinical Information

5-Hydroxyindoleacetic acid (5-HIAA) is the major metabolite of serotonin and is excreted in the urine. Intestinal carcinoid tumors along with neuroendocrine tumors can produce excess amounts of 5-HIAA and serotonin especially in individuals with carcinoid syndrome. Carcinoid syndrome is characterized by carcinoid tumors, flushing, heart disease, and hepatomegaly.

 

Measurement of 5-HIAA in a 24-hour urine specimen can diagnose carcinoid disease with a high specificity.

Reference Values

≤8 mg/24 hours

Cautions

Intake of food with a high content of serotonin (avocados, dates, eggplant, all fruit [including bananas, cantaloupe, grapefruit, kiwifruit, melons, pineapple, plantains, plums], all nuts [including hickory nuts, butternuts, pecans, walnuts], and tomatoes and tomato products) within 48 hours of the urine collection could result in falsely elevated 5-hydroxyindoleacetic acid (5-HIAA) excretion.

 

Numerous drugs affect the excretion of 5-HIAA by different mechanisms, including increased serotonin synthesis, metabolism, and release and inhibition of uptake. The following medications can interfere with 5-HIAA results. If clinically feasible, discontinue the following medications at least 48 hours before specimen collection.

-Pain relievers (specifically those containing acetaminophen [Tylenol], salicylates [aspirin] or phenacetin)

-Cough syrups containing guaifenesin or antihistamines

-Nasal drops and sprays

-Muscle relaxants containing mephenesin or methocarbamol (Robaxin, Flexeril, and Valium for example)

-Antidepressants including tricyclic antidepressants (imipramine, for example) and monamine oxidase inhibitors (MAOIs) (Nardil, for example)

-Hypertensive medications (Reserpine, for example)

-Isoniazid (antibiotic used to fight tuberculosis and other diseases)

-Methenamine (antibiotic used to fight urinary tract infections)

-Heparin (anticoagulant used as a blood thinner)

-L-dopa (Levodopa such as Sinemet, or Methyldopa, used to treat high blood pressure, for example)

-Phenothiazines (Compazine or Thorazine for example, used to treat mental or emotional disorders)

 

Patient should also avoid tobacco, tea and coffee for 48 hours before and during specimen collection.

Day(s) Performed

Monday through Thursday; 11 a.m.; Friday: 2 p.m.

Report Available

2 days (not reported on Saturday or Sunday)

Performing Laboratory

Mayo Medical Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information

83497

NY State Approved

Yes