| Laboratory: | Clinical Biochemistry (SPECIAL CHEMISTRY) | ||||
| Test Name: |
5 - HYDROXYINDOLEACETIC ACID (5-HIAA), RANDOM OR 24H URINE - (U)
Test Code:
HIAA
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| Clinical Information: |
Description: 5-Hydroxyindoleacetic acid (5-HIAA) is the principal metabolite of serotonin, and the quantitative urinary excretion of 5-HIAA is used to diagnose serotonin overproduction by carcinoid tumors.
Patient Preparation Instructions: Patient should avoid food high in indoles: avocados, banana, tomato, plum, walnut, pineapple, eggplant. In general fruits and nuts should be avoided for 72 hours. Many over-the-counter and prescription medication affect 5-HIAA, consult your physician prior to discontinuing. For example, cough, antihistamine, Tylenol, aspirin, muscle relaxants, nasal drops and sprays, and hypertension medication (see More Information below). Various natural herbs in supplements and health food interfere with serotonin metabolism to 5-HIAA and should be avoided for at least 3 days prior to testing. Patient should also avoid tobacco, tea, coffee and caffeinated drinks (soda/cola) for three days prior to specimen collected. |
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| Collection Devices: |
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| Specimen Required: |
Urine: 10.0 mL
Pediatric Urine: 1.0 mL
Collection Information: If collecting 24h urine, refrigerate during collection. If collecting random urine, morning void is preferred. Special Processing: Prepare two aliquots for random or 24h urine. No preservative is required. Acidified urine (pH<4) is NOT acceptable. One aliquot for urine creatinine to Automated chemistry can be sent refrigerated and the second aliquot for 5-HIAA testing should be frozen immediately to minimize oxidation of 5-HIAA. For details refer to JA110-50-01A 24 Hour Urine Processing Flow Chart Specimen Stability: Ambient: 48 hours Refrigerated: 4 weeks Frozen: 6 months |
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| Referral: |
Shipping & Storage: Store and ship to HSC frozen.
Testing Laboratory (MB): HSC Clinical Biochemistry Mass Spectrometry/Metabolic Lab (204)-787-4530 |
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| Requisition: | |||||
| Reference Values: |
< 5 μmol/mmol creatinine
Method of Analysis: Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS) |
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| Availability: |
Within 10 Days
For urgent testing, consult Clinical Biochemist of Duty 431-276-4861
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| See Also: | |||||
| More Information: |
Interpretation & Assay Interferences: Medications/factors that decrease 5-HIAA levels are as follows: Aspirin, Corticotropin, Ethanol, Isoniazid, Homogentisic acid, Imipramine, Monoamine oxidase inhibitors (MAOIs), Methyldopa, Promethazine, Phenothiazines, Perchlorperazine, Octreotide, Fluoxetine
Medications/factors that increase 5-HIAA levels are as follows: Recent surgery, Stress, Acetaminophen, Caffeine, Diazepam, Ephedrine, 5-Fluorouracil, Guaifenesin, Melphalan, Naproxen, Nicotine, Phenobarbitone, Phentolamine, Reserpine |