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HelpTest Code LAB14408 5-Hydroxyindoleacetic Acid, Plasma
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.
Secondary ID
619735Useful For
Biochemical diagnosis and monitoring of intestinal carcinoid syndrome using a plasma specimen
Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Reporting Name
5-Hydroxyindoleacetic Acid, PSpecimen Type
PlasmaSpecimen Minimum Volume
0.2 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Plasma | Frozen (preferred) | 60 days |
| Refrigerated | 72 hours |
Reject Due To
| Gross hemolysis | OK |
| Thawing** | Cold OK; Warm reject |
| Gross lipemia | OK |
| Gross icterus | OK |
Reference Values
≤6 months: ≤130 ng/mL
>6 months: ≤30 ng/mL
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 walnuts, hickory nuts, butternuts, pecans, walnuts], and tomatoes and tomato products) within 24 hours of the plasma 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:
-Acetaminophen (Tylenol or generic versions)
-Tryptophan containing supplements
Day(s) Performed
Monday, Wednesday, Thursday, Friday
Report Available
2 to 4 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
83497
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| HIAAP | 5-Hydroxyindoleacetic Acid, P | 1693-1 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 619735 | 5-Hydroxyindoleacetic Acid, P | 1693-1 |