HYDROXY INDOLE ACETIC ACID (5-HIAA)

5-Hydroxyindole acetic acid ( 5-HIAA) is a metabolite of neurotransmitter Serotonin. Normally 1-3 % of dietary Tryptophan is metabolized to Serotonin, but in patients with intestinal Carcinoid syndrome, 60% of Tryptophan is converted to Serotonin. Elevated excretion of 5-HIAA is a probable indicator of the presence of serotonin producing tumor. This assay is used in the biochemical diagnosis and monitoring of intestinal Carcinoid syndrome.