Borrelia burgdorferi IgG Antibody, Serum
This test measures the presence of antibodies in your blood that your immune system produces in response to *Borrelia burgdorferi*, the bacterium responsible for Lyme disease. Antibodies can help your body fight infection but may also indicate past or ongoing exposure.
["This test helps diagnose Lyme disease by detecting your immune system’s reaction to the Lyme bacteria."]
Key facts at a glance
- LOINC
- 48719-9
- Short code
- COX2IGG
- Synonyms
- C burnet Ph2 IgG Ser Ql IF
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or red-top tube (no anticoagulant)
- Units
- N/A
- Ref low
- 0
- Ref high
- 1
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Immunofluorescence Assay (IFA) using phase 2 antigen of Coxiella burnetii to detect IgG antibodies
- CPT
- 86638
- SNOMED
- 313680009
- Specimen volume
- 1 mL serum (minimum 0.5 mL)
- Stability
- Stable at room temperature for 8 hours, refrigerated (2–8°C) for 7 days, frozen at -20°C or below for up to 30 days. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 2
- Lipemia max
- 3
- Icterus max
- 2
- TAT
- 24–96 hours
- Order
- routine
Why This Test Is Done
Your healthcare provider may order this test if you have symptoms of Lyme disease, such as a rash (like a bullseye rash), flu-like symptoms, or joint/muscle pain. It can also be used to check for past infection or monitor treatment progress. The test is often done on blood drawn from a vein in your arm.
What to Expect Before the Test
No special preparation is needed. You may have a small bandage on the site where the blood is drawn, but it’s normal to feel a slight pinch. If you’re on blood-thinning medication, let your provider know before the test.
What to Expect During the Test
A healthcare professional will insert a needle into your arm and collect a small amount of blood. The process usually takes a few minutes. You may feel a brief sting, but it’s over quickly.
What to Expect After the Test
After the needle is removed, you may feel a small bruise or soreness at the site. Apply gentle pressure to stop any bleeding. Avoid heavy lifting or strenuous activity for a few hours. Most people return to normal activities immediately.
Reference range
Negative: <1:16; Equivocal: 1:16–1:32; Positive: ≥1:64. Phase 2 IgG titers indicate exposure to Coxiella burnetii (Q fever) and help distinguish acute from chronic infection when interpreted alongside phase 1 IgG titers.N/A
No fasting required. No special patient preparation is needed for this serological test. Patients should inform their healthcare provider of any recent vaccinations, infections, or immunosuppressive therapy, as these may affect antibody response.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Positive results (detecting IgG antibodies) suggest you’ve had exposure to *Borrelia burgdorferi* at some point, which may mean you’ve had Lyme disease in the past. However, IgG antibodies can remain in your blood for years after infection. Early treatment with antibiotics is key to preventing complications like heart or nerve damage. If symptoms persist or worsen, your provider may recommend additional testing or retesting.
Short name
IgG Antibody to Lyme Disease Spirochete
Frequently asked questions
How long does it take to get results?
What does a positive result mean?
Can I have false positives or false negatives?
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