Lyme disease (Borellia burgdorferi) IgG - Immunoblot

Lyme Disease (Borrelia burgdorferi) IgG Immunoblot Test

The Lyme Disease (Borrelia burgdorferi) IgG Immunoblot Test is a confirmatory blood test used to detect IgG antibodies against Borrelia burgdorferi, the bacterium that causes Lyme disease. This test is typically performed after an initial positive or equivocal Lyme antibody screening test (ELISA or EIA) to help confirm the diagnosis.

Lyme disease is a tick-borne bacterial infection transmitted primarily through the bite of infected Ixodes (black-legged or deer) ticks. It is common in parts of North America, Europe, and Asia. Early diagnosis and treatment are important because untreated Lyme disease can affect the skin, joints, nervous system, and heart.

Early symptoms may include:

• Expanding rash (erythema migrans or "bull's-eye" rash)
• Fever
• Fatigue
• Headache
• Muscle and joint pain
• Swollen lymph nodes

If left untreated, Lyme disease may progress to:

• Arthritis, especially of the knees
• Facial nerve palsy (Bell's palsy)
• Meningitis
• Peripheral neuropathy
• Heart rhythm abnormalities (Lyme carditis)

The immune system begins producing IgG antibodies several weeks after infection. Therefore, the IgG Immunoblot is most useful in later stages of Lyme disease or in patients with symptoms lasting more than four weeks.

Unlike screening tests, the Immunoblot detects antibodies against multiple specific Borrelia proteins, making it more specific and reducing false-positive results. The test is interpreted according to established diagnostic criteria by identifying characteristic antibody bands.

A positive IgG Immunoblot supports Lyme disease only when interpreted together with compatible clinical symptoms and exposure history. Since IgG antibodies may remain detectable for months or years after successful treatment, a positive result does not necessarily indicate an active infection.

Benefits of the Test

• Confirms Lyme disease after a positive screening test.
• Detects IgG antibodies against Borrelia burgdorferi.
• Highly specific confirmatory test.
• Helps reduce false-positive screening results.
• Requires only a blood sample.
• Supports diagnosis of late Lyme disease.
• Assists clinicians in treatment decisions.
• Complements clinical evaluation.

Why Doctors Recommend This Test

Doctors recommend the Lyme Disease IgG Immunoblot when a patient has a positive or equivocal Lyme antibody screening test, compatible symptoms, and a history of possible tick exposure.

Preparation Before the Test

No special preparation is required.

You may eat and drink normally unless instructed otherwise. Inform your healthcare provider about tick bites, travel to Lyme-endemic areas, previous Lyme disease, antibiotic treatment, and current symptoms. A blood sample is collected from a vein for laboratory analysis.

Normal Reporting Time

Typically: 3–7 Working Days

Reporting time may vary depending on the laboratory methodology.

Who Should Take This Test?

This test may be recommended for:

• Individuals with a positive or equivocal Lyme screening test.
• Patients with suspected late Lyme disease.
• People with arthritis following tick exposure.
• Individuals with unexplained neurological symptoms.
• Patients with suspected Lyme carditis.
• People living in or returning from endemic regions.
• Individuals with persistent symptoms after tick exposure.
• Patients referred by infectious disease specialists.
• Individuals undergoing confirmatory testing.
• Anyone advised by their healthcare provider.