Lyme Disease Ab with Reflex to Blot (IgG, IgM)
This test screens a blood sample for antibodies to Borrelia burgdorferi, the bacterium that causes Lyme disease. If the initial screen is positive, the same sample automatically reflexes to a confirmatory immunoblot test, following the two-step approach used for Lyme antibody testing.
About this test
Lyme disease is caused by Borrelia burgdorferi, a bacterium spread by tick bites. This test looks for IgG and IgM antibodies the body makes in response, using an immunoassay screening method.
When the initial Lyme antibody screen result meets the threshold Quest defines for that assay, the same sample reflexes automatically to an immunoblot, or Western blot, test that examines the antibody response in more detail. This second step adds specificity, which is why the two-step approach is used rather than a screening result alone.
Who might consider this test?
- People who talk with their clinician about this test are typically being evaluated for possible Lyme disease exposure or symptoms consistent with it.
Test details
| Quest code | 6646 |
|---|---|
| Methodology | Immunoassay |
| Sample type | 1 mL serum |
| Collection | Quest patient service center |
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Quest resources
Additional details
What this test looks at
The screening portion reports one analyte: the Lyme antibody screen result, an immunoassay measurement of IgG and IgM antibodies to Borrelia burgdorferi. Quest lists several alternate names for this area, including Lyme, Borrelia burgdorferi and Western blot.
How the reflex testing works
If the initial screen result meets the threshold Quest sets for that assay, the laboratory automatically runs a confirmatory immunoblot on the same sample rather than requiring a new order or a second draw. This follows the CDC-recommended two-step algorithm, which pairs a sensitive first test with a more specific second test before a result is considered reactive.
This test isn't orderable through the store yet. Requesting it tells us you want it and puts you on the list to be told when that changes — there is no charge and no commitment, and requesting does not place an order.
Laboratory results should always be interpreted by a licensed clinician who knows your health history. This page is information about a test, not medical advice.
Frequently asked questions
What does this test measure?
It measures IgG and IgM antibodies to Borrelia burgdorferi, the bacterium that causes Lyme disease, starting with an immunoassay screen.
How is the sample collected?
Through a routine blood draw that produces a serum sample.
Do I need to prepare for this test?
No preparation instructions are listed for this test, though people follow any instructions their ordering clinician provides.
What happens if the screening result is positive?
The same sample automatically reflexes to a confirmatory immunoblot (Western blot) test, following the CDC-recommended two-step approach for Lyme antibody testing.
Is this the same as a Western blot test?
The immunoblot, or Western blot, step is part of this test, run automatically when the initial screen meets Quest's threshold. It is not a separate, stand-alone order under this test code.