Alpha-Fetoprotein (AFP), Cerebrospinal Fluid — Concentration
This specialized test measures alpha-fetoprotein (AFP) in cerebrospinal fluid. It may be used in selected evaluations for brain or spinal cord tumors.
["An elevated AFP level in cerebrospinal fluid can support evaluation for certain AFP-producing tumors, but it is not diagnostic by itself."]
Key facts at a glance
- LOINC
- 59564-5
- Short code
- AFP CSF-aCnc
- Synonyms
- AFP CSF-aCnc
- Category
- liver
- Sample
- csf
- Container
- Sterile tube
- Units
- N/A
- Ref low
- 0
- Ref high
- 10
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 82105
- SNOMED
- 394971007
- Specimen volume
- 1-2 mL
- Stability
- Immediate analysis required, Refrigerated: 1h
- Hemolysis max
- 200
- TAT
- 4–24 hours
- Order
- routine
What is this test?
Alpha-fetoprotein, or AFP, is a protein that can be produced by certain tumors, especially some germ-cell tumors. This test measures the amount of AFP in cerebrospinal fluid, the fluid surrounding the brain and spinal cord.
Why might I need this test?
CSF AFP testing may be ordered in selected patients being evaluated for a brain or spinal cord tumor, particularly when symptoms or imaging raise concern for an AFP-producing tumor. It is not a general screening test and is usually interpreted with other clinical and diagnostic findings.
How is the test performed?
Cerebrospinal fluid is usually collected through a lumbar puncture, also called a spinal tap. A laboratory then measures AFP in the collected fluid.
How do I prepare for the test?
Follow the instructions provided by your clinician, particularly if a lumbar puncture is planned. You may be asked to lie on your side with your knees drawn up; local anesthetic is often used, and no special fasting period is usually required.
Reference range
Normal: <10 ng/mLN/A
No special preparation required. For PSA, avoid sexual activity for 24-48 hours before the test.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
An elevated AFP concentration in cerebrospinal fluid may occur with certain AFP-producing brain or spinal cord tumors, including some germ-cell tumors. However, blood contamination or transfer of AFP from the bloodstream into the fluid can also raise the result, so an abnormal value must be interpreted with symptoms, imaging, and other laboratory findings.
Short name
CSF Alpha-Fetoprotein
Frequently asked questions
Is this the same as a routine blood AFP test?
Does an elevated CSF AFP result diagnose cancer?
Is the lumbar puncture painful?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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