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Kynurenine in Cerebrospinal Fluid (CSF)

Published: August 9, 2026Updated: August 16, 2026

This test measures the level of kynurenine, a breakdown product of the amino acid tryptophan, found in your spinal fluid. It may be checked to help evaluate certain neurological conditions.

Quick summary

["Kynurenine levels in CSF can provide clues about brain chemistry and potential neurological health concerns."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
74942-4
Short code
Kynurenin CSF-sCnc
Synonyms
Kynurenin CSF-sCnc
Category
chemistry
Sample
csf
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
1-2 mL
Stability
Immediate analysis required, Refrigerated: 1h
Hemolysis max
200
TAT
4–24 hours
Order
routine

Why Might This Test Be Ordered?

Your healthcare provider may recommend this test if you have symptoms like headaches, confusion, seizures, or neurological issues that suggest metabolic or neurodegenerative conditions. It could also be part of a broader evaluation for conditions affecting brain chemistry, such as certain genetic disorders or metabolic diseases.

What Does This Test Measure?

Kynurenine is a metabolite produced when tryptophan breaks down in the body. Elevated levels in CSF might indicate abnormal metabolic pathways or conditions affecting brain function, though specific causes depend on clinical context.

Sample Collection and Preparation

A small amount of cerebrospinal fluid is collected through a procedure called a lumbar puncture (spinal tap). The fluid is then sent to the lab for analysis. This test is typically done when other tests or symptoms suggest a need for CSF chemistry evaluation.

What Are Common Clinical Uses?

This test is less commonly used alone but may be part of a diagnostic workup for conditions like mitochondrial disorders, certain neurodegenerative diseases, or metabolic syndromes affecting the brain. It can help assess biochemical imbalances in the central nervous system.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Elevated or low kynurenine levels in CSF may suggest underlying metabolic or neurological disorders, but interpretation requires clinical correlation with symptoms and other test results. Always discuss findings with your healthcare provider.

Short name

CSF Kynurenine

Frequently asked questions

What does a high or low kynurenine level in CSF mean?
A high level may indicate abnormal tryptophan metabolism or conditions affecting brain chemistry, but results alone don’t diagnose a specific condition. Your provider will consider symptoms, other tests, and medical history.
How is this test different from blood kynurenine tests?
This test specifically measures kynurenine in cerebrospinal fluid, which reflects brain chemistry, whereas blood tests measure kynurenine in your bloodstream. CSF tests are used when neurological involvement is suspected.
Is this test painful?
The lumbar puncture procedure may cause mild discomfort, but it is generally well-tolerated. You may experience temporary soreness or headache afterward, which can be managed with rest and pain relief as directed by your provider.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy