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IgG to Borrelia burgdorferi (Lyme disease antibody)

Published: August 9, 2026Updated: August 16, 2026

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.

Quick summary

["Helps diagnose Lyme disease by detecting your immune system’s reaction to the infection."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
111306-7
Short code
COXPH1M
Synonyms
C burnet Ph1 IgM Msmt Ser
Category
chemistry
Sample
serum
Container
Serum separator tube (SST) or red-top clot activator tube
Units
N/A
Ref low
0
Ref high
1
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
Enzyme-linked immunosorbent assay (ELISA) or Indirect Immunofluorescence Assay (IFA) for detection of IgM antibodies against Coxiella burnetii phase I antigen
CPT
86638
SNOMED
313327003
Specimen volume
1-2 mL serum
Stability
Serum stable for 7 days at 2-8°C; for extended storage, freeze at -20°C or below. Avoid repeated freeze-thaw cycles.
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
24–72 hours
Order
routine

What This Test Measures

The test looks for IgG antibodies against *Borrelia burgdorferi*, a bacterium transmitted primarily through tick bites. These antibodies indicate whether your body has been exposed to the bacteria at some point, even if symptoms have already cleared or the infection is in an early stage.

Why It’s Ordered

Your healthcare provider may order this test if you have symptoms of Lyme disease (e.g., rash, joint pain, fatigue) or if you’ve been in an area with high tick activity. It’s also used to monitor treatment effectiveness or check for past exposure.

How the Test Works

Blood is drawn and tested using an immunoassay method to detect IgG antibodies specific to *Borrelia burgdorferi*. This method identifies whether your immune system has recognized and fought the bacteria.

What to Expect Before the Test

No special preparation is needed. You may eat and drink normally, but inform your provider if you’re on blood-thinning medications or have a bleeding disorder.

Reference range

Negative: <1:16 titer or below assay-specific cutoff (varies by laboratory). Equivocal/Positive: ≥1:16 or above assay cutoff. A fourfold rise in titer between acute and convalescent sera confirms recent infection.N/A

Specimen: serum

No fasting required. Patient should inform clinician of recent antibiotic use, vaccination history (e.g., Q fever vaccine), occupational exposure to livestock, and travel history. Acute and convalescent serum samples (2-4 weeks apart) are recommended for accurate diagnosis.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

IgG Antibody to Borrelia burgdorferi

Frequently asked questions

IgG antibodies to *Borrelia burgdorferi* can appear weeks to months after infection, even if symptoms have resolved. While they don’t always confirm active Lyme disease, they suggest past exposure. False positives can occur in rare cases, so results should be interpreted by a healthcare provider in the context of symptoms and clinical history.
This test alone cannot diagnose Lyme disease. It may be used alongside other tests (like ELISA or Western blot) or clinical findings to guide treatment decisions.
Can this test detect Lyme disease if I’ve already been treated?
Yes, it can detect past exposure even after treatment. IgG antibodies may linger for months or years, so a positive result doesn’t necessarily mean the infection is active. Your provider will consider other factors, such as symptoms or recent tick exposure.
What if my test results are positive but I don’t have symptoms?
A positive IgG result could mean you had Lyme disease in the past, but you may not have symptoms now. It’s important to discuss this with your healthcare provider to assess whether further testing or monitoring is needed, especially if you’ve been in a high-risk area recently.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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