Anti-CASPR2 Antibody (Serum)
This test measures the presence of antibodies directed against the CASPR2 protein, which may be linked to certain autoimmune neurological conditions.
["This test helps diagnose or monitor conditions like limbic encephalitis or other autoimmune-related neurological symptoms."]
Key facts at a glance
- LOINC
- 94285-4
- Short code
- CASPR2
- Synonyms
- CASPR2 IgG Ser Ql CBA IFA
- Category
- chemistry
- Sample
- serum
- Container
- Red-top or serum separator tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–99 years
- Method
- cba-ifa
- CPT
- 86255
- SNOMED
- 122913008
- Specimen volume
- 1 mL serum (minimum 0.5 mL)
- Stability
- Stable for 7 days at 2-8°C; for extended storage, freeze at -20°C or below for up to 6 months; avoid repeated freeze-thaw cycles
- Hemolysis max
- 100
- Lipemia max
- 100
- Icterus max
- 50
- TAT
- 48–168 hours
- Order
- routine
Why This Test Might Be Ordered
Your doctor may recommend this test if you have symptoms such as memory problems, confusion, seizures, or unusual movements that could suggest an autoimmune neurological disorder. It may also be used in patients with known conditions like limbic encephalitis or other autoimmune encephalitides.
What to Expect During Testing
A blood sample will be drawn from a vein in your arm. You may feel a slight pinch when the needle is inserted, but the procedure is quick and usually not painful. No special preparation is needed, but inform your doctor about any medications you’re taking.
Possible Results and Next Steps
If your results are positive for anti-CASPR2 antibodies, this may support a diagnosis of autoimmune-related neurological conditions. Your doctor will discuss the results with you and may recommend further testing or treatment options based on your symptoms and overall health.
What This Test Measures
This test detects specific antibodies in your blood that target the CASPR2 protein, which is involved in nerve function. These antibodies are associated with certain autoimmune disorders affecting the brain and nervous system.
Reference range
NegativeN/A
No special preparation required. Specimen should be collected prior to initiation of immunosuppressive therapy when possible, as treatment may affect antibody titers
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Anti-CASPR2 antibodies are linked to autoimmune limbic encephalitis, a rare condition that can cause inflammation in the brain’s limbic system, leading to memory loss, mood changes, seizures, and other neurological symptoms. While not all positive results indicate a definite diagnosis, they are important markers for further evaluation and treatment planning.
Short name
Anti-CASPR2 IgG
Frequently asked questions
What does a positive result mean?
Will I need more tests if this result is positive?
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 15, 2026. · Read our editorial policy