IgM Antibody to Borrelia burgdorferi (Lyme Disease) by Immunoassay
This test measures the presence of IgM antibodies against *Borrelia burgdorferi*, the bacterium responsible for Lyme disease. These antibodies develop in your blood after infection, typically appearing within weeks to months.
["Detects early Lyme disease infection with IgM antibodies."]
Key facts at a glance
- LOINC
- 41841-8
- Short code
- COXIGM
- Synonyms
- C burnet Ph1+2 IgM Pnl Titr Ser
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or red-top tube with serum transfer to sterile cryovial
- Units
- N/A
- Ref low
- 0
- Ref high
- 1
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Immunofluorescence assay (IFA) for detection of IgM antibodies against Coxiella burnetii phase 1 and phase 2 antigens
- CPT
- 86638
- SNOMED
- 122310008
- Specimen volume
- 1-2 mL serum (minimum 0.5 mL)
- Stability
- Stable for 7 days at 2-8°C; for longer storage, freeze at -20°C or below. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 48–168 hours
- Order
- routine
What This Test Measures
IgM antibodies are a type of immune protein your body produces in response to infection. In Lyme disease, these antibodies can appear in your bloodstream shortly after exposure to the *Borrelia burgdorferi* bacterium. This test helps identify if you may have been infected recently, though they may not be present long-term.
When You Might Need This Test
Your healthcare provider may recommend this test if you have symptoms of Lyme disease (such as a bull’s-eye rash, flu-like illness, or joint/muscle pain) and suspect exposure to ticks. It’s often used in early diagnosis, especially when other tests (like IgG) are not yet conclusive.
What to Expect Before the Test
No special preparation is needed. You’ll provide a blood sample, usually drawn from a vein in your arm. The test is quick and typically done in a lab setting.
What the Results Mean
Positive results suggest recent infection with *Borrelia burgdorferi*. However, false positives can occur, so results should be interpreted by your doctor alongside clinical symptoms and other tests. Negative results mean no detectable IgM antibodies were found at the time of testing.
Reference range
Negative: Titer < 1:16 for both phase 1 and phase 2 IgM. Positive results are reported as the highest dilution showing detectable antibody (e.g., 1:64, 1:128, 1:256, etc.).N/A
No special patient preparation required. Acute phase specimen should be collected within the first 2-3 weeks of symptom onset; convalescent specimen should be collected 2-6 weeks later for paired testing.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance
Short name
IgM Lyme Antibody
Frequently asked questions
Why is this test important?
What does a positive result mean?
Can I get this test if I’ve already been treated for Lyme disease?
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