Borrelia burgdorferi B31 Ab.IgM
A blood test to detect IgM antibodies against Borrelia burgdorferi, the bacterium that causes Lyme disease, using line blot methodology.
Detects early immune response to Lyme disease bacteria IgM antibodies typically appear 2-4 weeks after tick bite Positive result suggests recent or early infection Results should be interpreted with clinical symptoms Often followed by IgG testing for confirmation
Key facts at a glance
- LOINC
- 104602-8
- Short code
- LYMBM
- Synonyms
- B. burgdorferi B31 IgM Ser Ql Line blot
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or red-top tube
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- line-blot
- CPT
- 86617
- SNOMED
- 441943006
- Specimen volume
- 1-2 mL serum
- Stability
- Stable for 7 days at 2-8°C; stable for 30 days at -20°C; avoid repeated freeze-thaw cycles
- Hemolysis max
- 100
- Lipemia max
- 100
- Icterus max
- 50
- TAT
- 24–72 hours
- Order
- routine
What is this test, and what does it measure in your body?
The Borrelia burgdorferi IgM Antibody Test (Line Blot) is a specialized blood test that detects IgM antibodies specific to the bacteria causing Lyme disease. The line blot technique is a confirmatory method that can identify antibodies to multiple bacterial proteins, providing more detailed information than standard screening tests.
Why do I need this test, and what conditions can it help detect or monitor?
Your healthcare provider may order this test if you have symptoms suggesting Lyme disease, especially if you have been in an area where Lyme disease is common or have a known tick bite history. Symptoms may include: the characteristic 'bull's-eye' rash (erythema migrans), fever, headache, fatigue, and muscle aches. The IgM test is most useful in the early stages of infection, typically within 2-4 weeks after exposure.
How is this test performed, and what should I expect during the procedure?
A blood sample will be drawn from a vein in your arm. The sample is then sent to a laboratory where technicians will use the line blot technique to detect IgM antibodies against Borrelia burgdorferi. This method separates bacterial proteins and tests them individually, providing more specific results than simpler screening tests.
Your results will be compared with standard reference ranges to show whether your values fall within the expected limits, and your healthcare provider will explain what the numbers mean for your overall health and whether any follow-up testing or changes to your care plan are needed.
A positive IgM result suggests your immune system has produced antibodies in response to a recent Lyme disease infection. However, results must be interpreted carefully: some people may have false-positive results, and the test cannot distinguish between past infection and current infection. Your healthcare provider will consider your symptoms, exposure history, and may order follow-up IgG antibody testing to confirm the diagnosis.
Reference range
NegativeN/A
No special preparation required. Sample should be collected prior to administration of antibiotics for optimal IgM antibody detection.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
The IgM line blot test is primarily used to detect early Lyme disease infection. IgM antibodies are produced first by the immune system, making this test valuable for early diagnosis. A positive or indeterminate result in the presence of characteristic symptoms supports a diagnosis of early Lyme disease. However, sensitivity is limited in the first few weeks of infection. The test is often repeated or supplemented with IgG antibody testing (which appears later) to confirm diagnosis. False positives can occur in patients with other conditions such as syphilis, Rocky Mountain spotted fever, or certain autoimmune diseases.
Frequently asked questions
Do I need to fast before this test?
How long does it take to get results?
What does a negative result mean?
Can I have Lyme disease if this test is negative?
Do I need to do anything special after the test?
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 15, 2026. · Read our editorial policy