79574-0

LOINC code 79574-0 identifies "Folate and tryptophan and metabolites pattern [Interpretation] in Cerebral spinal fluid Narrative". Testing for folate and its metabolites as well as tryptophan and its metabolites in CSF can be useful in distinguishing among various central nervous system disorders associated with folate deficiency. Low folate levels are associated with inborn errors of metabolism, including cerebral folate deficiency (CFD), a neurological syndrome that occurs around 2-4 months of age and is primarily associated with associated with low levels of 5-methyltetrahydrofolate (5-MTHF) in the CSF with normal folate levels in the plasma and red blood cells.[PMID: 19260931] Low folate levels are also associated with depression and dementia in elderly patients.[PMID: 11183038] Serotonin, which is formed from tryptophan, may be the link between folate and depression or dementia. Many patients with neuropsychiatric disorders and folate deficiency have also been found to have low levels of 5-hydroxyindoleacetic acid (5-HIAA, a serotonin metabolite), and patients with 5,10-methylenetetrahydrofolate reductase (MTHFR) deficiency also have decreased serotonin synthesis. [PMCID: 1810582]

This code measures Folate & tryptophan & metabolites pattern in CSF. It belongs to the CHEM class in the LOINC classification.

LOINC (Logical Observation Identifiers Names and Codes) is a universal standard for identifying laboratory and clinical observations. It is maintained by the Regenstrief Institute and used worldwide for health data exchange.