Ordering Guidance

This test quantifies 5-hydroxyindoleacetic acid in plasma specimens and is comparable to testing on 24-hour and random urine specimens for the diagnosis and monitoring of intestinal carcinoid syndrome.

Necessary Information

Patient's age is required.

Specimen Required

Patient Preparation:

1. Some medications could interfere with test results. If medically feasible, for 48 hours before and during specimen collection, patient should not take the following medications:

-Acetaminophen (Tylenol or generic versions)

-Tryptophan containing supplements.

2. For 24 hours prior to and during collection, the patient should limit the following to one serving per day:

-Fruits

-Vegetables

-Caffeinated beverages or foods

3. For 24 hours prior to and during collection, patients should not eat nuts, especially walnuts. Plasma 5-hydroxyindoleacetic acid levels revert to baseline levels when walnuts are ingested after other foods.

Supplies: Sarstedt Aliquot Tube, 5 mL (T914)

Collection Container/Tube:

Preferred: Green top (sodium heparin)

Acceptable: Lavender top (EDTA)

Submission Container/Tube: Plastic vial

Specimen Volume: 0.5 mL

Collection Instructions:

1. Centrifuge at 4° C.

2. Aliquot plasma into plastic vial.

3. Send plasma frozen.