Coxsackievirus B IgM Antibody Test
A blood test that looks for IgM antibodies to Coxsackievirus B, a common virus that can sometimes cause inflammation of the heart.
{"This test checks for IgM antibodies indicating a recent Coxsackievirus B infection","It helps diagnose viral myocarditis and pericarditis","A positive result suggests a current or recent infection within the past few weeks","The test uses a neutralization assay to detect virus-fighting antibodies","Results should be interpreted by your healthcare provider in context of your symptoms"}
Key facts at a glance
- LOINC
- 16686-8
- Short code
- COXB IgM
- Synonyms
- CV B IgM Ser Nt-aCnc
- Category
- cardiac
- Sample
- serum
- Container
- Serum separator tube (SST) or plain red top tube
- Units
- N/A
- Ref low
- 0
- Ref high
- 1
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 0–120 years
- Method
- Virus Neutralization Test (VNT) - Serum antibody neutralization assay using cell culture
- CPT
- 86658
- SNOMED
- 371949004
- Specimen volume
- 1.0 mL minimum, 2.0 mL preferred for adequate testing
- Stability
- Room temperature: 24 hours; Refrigerated (2-8°C): 5-7 days; Frozen (-20°C or below): 30 days. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 50
- Lipemia max
- 100
- Icterus max
- 20
- TAT
- 72–168 hours
- Order
- routine
What is this test?
The Coxsackievirus B IgM Antibody test is a blood test that detects IgM antibodies specifically produced by your immune system in response to Coxsackievirus B infection. This test uses a neutralization test method, which is highly specific and measures your body's ability to neutralize the virus. IgM antibodies are typically the first antibodies your body produces when fighting a new infection, making this test useful for detecting recent or acute infections.
Why is it ordered?
This test is primarily ordered when you have symptoms suggestive of Coxsackievirus B infection, especially cardiac symptoms such as chest pain, shortness of breath, rapid heartbeat, or signs of heart inflammation. It is commonly used to help diagnose viral myocarditis (inflammation of the heart muscle), pericarditis (inflammation of the heart sac), or other heart-related complications caused by this virus. Your doctor may also order this test if you have unexplained flu-like symptoms combined with heart symptoms.
How is the test performed?
A healthcare professional will draw a blood sample from a vein in your arm. The blood sample is then sent to a laboratory where technicians will use a neutralization assay to detect IgM antibodies against Coxsackievirus B. This method involves mixing your blood serum with the virus to see if antibodies in your blood can neutralize or block the virus. The entire process is typically completed within a few days, depending on the laboratory.
What do the results mean?
A positive IgM result indicates that you have a recent or current Coxsackievirus B infection, typically within the past 2-6 weeks. A negative result suggests no recent infection, though it does not rule out past exposure. Your doctor will interpret these results together with your clinical symptoms, physical examination, and possibly other tests such as ECG or echocardiogram to make a complete diagnosis. False positives or negatives can occur, so clinical correlation is essential.
Reference range
Negative: <1:8 titer (no detectable neutralizing antibodies); Equivocal: 1:8 titer; Positive: ≥1:8 titer (presence of neutralizing IgM antibodies)N/A
No special preparation required. Inform laboratory of recent infections, immunizations, or immunosuppressive therapy. Exercise caution with patients having autoimmune conditions as rheumatoid factor may cause false-positive IgM results.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Coxsackievirus B is a significant cause of viral myocarditis, which can lead to heart muscle damage, heart failure, and in severe cases, sudden cardiac death. Early detection of Coxsackievirus B infection through IgM antibody testing is crucial for appropriate management and monitoring of cardiac complications. This test helps differentiate viral myocarditis from other causes of heart inflammation and guides treatment decisions. In patients with suspected pericarditis, this test can help identify if a viral cause is responsible. Additionally, positive results may have implications for athletic activity restrictions, as viral myocarditis requires rest and careful monitoring before returning to physical activity.
Frequently asked questions
Do I need to fast before this test?
How long does it take to get results?
Is this test painful?
Can this test tell me if I had a past infection?
What should I do if my test is positive?
Sources
- 1
- 2
- 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 14, 2026. · Read our editorial policy