Coxsackievirus A4 Antibody Test, Cerebrospinal Fluid (CSF)
This test measures antibodies to Coxsackievirus A4 in the cerebrospinal fluid, the clear liquid that surrounds and cushions your brain and spinal cord. Doctors use it to help find out whether a viral infection is affecting your central nervous system, especially if you have symptoms such as severe headache, fever, stiff neck, confusion, or seizures.
{"The test looks for antibodies to Coxsackievirus A4 in the fluid surrounding the brain and spinal cord","A lumbar puncture (spinal tap) is used to collect the cerebrospinal fluid sample","This test helps doctors diagnose viral meningitis, encephalitis, or other nervous system infections caused by Coxsackievirus A4","Results are reported as a titer, indicating the level of antibodies present","Positive results suggest a recent or past infection with this specific virus"}
Key facts at a glance
- LOINC
- 16683-5
- Short code
- COXA4ABCSF
- Synonyms
- CV A4 Ab Titr CSF
- Category
- cardiac
- Sample
- csf
- Container
- Sterile polypropylene container for cerebrospinal fluid collection; avoid using containers with preservatives or additives
- Units
- N/A
- Ref low
- 0
- Ref high
- 1
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- Enzyme-linked immunosorbent assay (ELISA) or Immunofluorescence assay (IFA) for detection of Coxsackievirus A4-specific IgG and IgM antibodies in cerebrospinal fluid
- CPT
- 86658
- SNOMED
- 122442009
- Specimen volume
- 1-2 mL of cerebrospinal fluid; minimum 0.5 mL for testing
- Stability
- CSF should be transported to the laboratory immediately after collection. If testing cannot be performed within 2 hours, refrigerate at 2-8°C for up to 72 hours. For prolonged storage, freeze at -70°C or below; avoid repeated freeze-thaw cycles. Do not store at room temperature for extended periods as antibody activity may degrade.
- Hemolysis max
- 200
- TAT
- 48–168 hours
- Order
- routine
What is this test?
The Coxsackievirus A4 antibody test is a laboratory test that detects the presence of specific antibodies (immune proteins) against Coxsackievirus A4 in the cerebrospinal fluid (CSF). CSF is the clear fluid that surrounds and cushions the brain and spinal cord. This test helps determine if a viral infection is affecting the central nervous system.
How is the sample collected?
The cerebrospinal fluid is collected through a procedure called a lumbar puncture, commonly known as a spinal tap. During this procedure, a healthcare provider inserts a thin needle between the bones in the lower spine to withdraw a small amount of CSF. The area is first numbed with a local anesthetic to minimize discomfort.
Why might I need this test?
Your doctor may order this test if you have symptoms of a central nervous system infection such as meningitis (inflammation of the membranes surrounding the brain) or encephalitis (inflammation of the brain). Symptoms may include severe headache, fever, stiff neck, confusion, seizures, or unusual sleepiness. This test helps identify whether Coxsackievirus A4 is the cause of your symptoms.
What do the results mean?
Results are reported as a titer, which indicates the concentration of antibodies in the CSF. A positive result means that antibodies against Coxsackievirus A4 were detected, suggesting that you have or recently had an infection with this virus. A negative result means no antibodies were detected, but it does not completely rule out infection, especially if the test was done very early in the illness. Your doctor will interpret the results together with your symptoms and other test findings.
Are there any risks?
The lumbar puncture is generally safe, but some people may experience a headache, back pain, or slight bruising at the puncture site. Very rarely, infection or bleeding can occur. Your healthcare team will take precautions to minimize these risks.
Reference range
Negative or titer <1:4; positive results indicate intrathecal antibody production suggestive of central nervous system infection. IgM antibodies indicate recent or acute infection, while IgG antibodies indicate past exposure or persistent infection.N/A
No fasting required. Patient should be informed about the lumbar puncture procedure and provide consent. Routine precautions for lumbar puncture apply including proper positioning (lateral decubitus or sitting) and aseptic technique. Inform the laboratory if the patient has recently received intravenous fluids, blood products, or has a bleeding disorder.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Coxsackievirus A4 is a type of enterovirus that can cause infections ranging from mild cold-like symptoms to more serious conditions. While most commonly associated with hand, foot, and mouth disease in children, it can occasionally spread to the central nervous system, causing viral meningitis or encephalitis. Detecting specific antibodies in CSF helps confirm the diagnosis and guide appropriate management, as treatment is primarily supportive (focused on relieving symptoms) while the body fights the infection.
Frequently asked questions
Is this test painful?
How long does it take to get results?
Do I need to fast before this test?
Can this test distinguish between a current and past infection?
Is Coxsackievirus A4 the same as hand, foot, and mouth disease?
Sources
- 1
- 2Viral Meningitis - CDCSource
- 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