Anti-Caspr2 Antibodies in Cerebrospinal Fluid (CSF)
This test measures the presence of antibodies targeting the Caspr2 protein in your spinal fluid. These antibodies may be linked to certain neurological conditions.
["This test helps diagnose or monitor conditions affecting nerve function in the central nervous system."]
Key facts at a glance
- LOINC
- 101241-8
- Short code
- CASPR2-CSF-IF
- Synonyms
- CASPR2 Ab CSF Ql IF
- Category
- chemistry
- Sample
- csf
- Container
- Sterile, leak-proof polypropylene screw-cap tube; CSF collection tube (tube 3 or 4 recommended to minimize blood contamination)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Immunofluorescence (Cell-based indirect immunofluorescence assay, CBA-IFA)
- CPT
- 86255
- SNOMED
- 764901008
- Specimen volume
- 1-2 mL of cerebrospinal fluid
- Stability
- Room temperature: 8 hours; Refrigerated (2-8°C): 14 days; Frozen (-20°C or below): 6 months. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 200
- TAT
- 24–168 hours
- Order
- routine
Why This Test Is Done
Your doctor may order this test if you have symptoms like numbness, weakness, or balance issues that suggest nerve damage. It’s often used in cases suspected of inflammatory or autoimmune nerve disorders, such as certain types of neuropathy or demyelinating diseases.
What to Expect Before the Test
No special preparation is needed. A healthcare provider will collect a small amount of cerebrospinal fluid (CSF) from your lower back using a needle. You may feel a brief pinch, but the procedure is usually quick and well-tolerated.
What the Results Mean
Positive results (detecting Caspr2 antibodies) may indicate an autoimmune response targeting nerve proteins. This could support a diagnosis of conditions like chronic inflammatory demyelinating polyneuropathy (CIDP) or other related disorders. Results alone don’t confirm a diagnosis; they’re usually interpreted alongside clinical findings.
Possible Conditions Linked to Positive Results
Elevated antibody levels may be associated with conditions affecting nerve insulation or signaling, such as autoimmune neuropathies. However, false positives or other underlying causes could also be present.
Reference range
NegativeN/A
No special patient preparation required. Inform the ordering physician of any current immunosuppressive therapy as it may affect antibody titers.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
CSF Anti-Caspr2 Antibody
Frequently asked questions
What does a positive result mean for my health?
Will I need additional tests if this result is abnormal?
Can lifestyle changes help if this test is positive?
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