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Test ID: 5-Hydroxyindoleacetate (24h urine)
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5-Hydroxyindoleacetate (24h urine)
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5-Hydroxyindoleacetate (24h urine)
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Useful For
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Urine 5-hydroxyindoleacetate, or 5-hydroxyindoleacetic acid (5-HIAA), is useful in the investigation of carcinoid syndrome.
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Method name and description
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High performance liquid chromatography coupled to electrochemical detection.
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Clinical information
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Carcinoid syndrome is a type of neuroendocrine tumour usually presenting with non-specific symptoms such as cutaneous flushing, diarrhoea, and dyspnoea. Biochemically, carcinoid syndrome is commonly characterised by the excessive secretion of the hormone serotonin, and by the increased production of its metabolite 5-hydroxyindoleacetate (5-hydroxyindoleacetic acid; 5-HIAA). The measurement of 5-HIAA in urine can, therefore, provide evidence of carcinoid syndrome.
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Aliases
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5-Hydroxyindoleacetic acid
5-HIAA
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Specimen type / Specimen volume / Specimen container
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Specimen type: A 24h urine collection, protected from light.
Specimen volume: total urine volume collected in 24 hours.
Specimen container: Suitable plain urine container and must be covered against light.
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Collection instructions / Special Precautions / Timing of collection
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Serotonin is present in many foods, which should be avoided for at least 48h prior to, and during the 24h urine collection:
Pineapple
Banana
Walnut
Kiwi
Plums
Tomatoes
Avocado
Blackcurrant
Melon
Alcohol
In addition, certain medications can impact the excretion of 5-HIAA and should similarly be avoided:
Imipramine
Isoniazid
Levodopa
Methyldopa
Monoamine oxidase inhibitors
Reserpine
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Relevant clinical information to be provided
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Presenting clinical signs and symptoms
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Storage and transport instructions
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Transport Temperature: 2 - 30 °C and must be covered against light.
Storage Temperature: -18°C after add the preservative till the time for processing and must be covered against light.
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Specimen Rejection Criteria
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Insufficient sample volume received
Sample exposed to light
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Biological reference intervals and clinical decision values
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24h urine: 10.5 - 47.1 umol/24h
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Factors affecting test performance and result interpretation
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Many foods (see collection requirements) can increase the excretion of urine 5-HIAA.
Some medications can increase (e.g. cisplatin) or decrease (e.g. levodopa) the excretion of urine 5-HIAA.
Excessively acidified (pH<3) or alkaline (bacterial contamination) can destabilise urine 5-HIAA and lower the measured concentration.
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Turnaround time / Days and times test performed / Specimen retention time
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Turnaround time: 5 working days.
Times test performed: Once a week.
Specimen retention time: 30 days.
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