Borrelia Burgdorferi Antibody Test in Arizona

What this test measures

Lyme disease is transmitted by certain tick species, and the immune response to the bacterium includes IgM and IgG antibodies. IgM tends to appear earlier and IgG later, so the pattern of results can carry information about timing. A blood test does not detect the bacterium directly, and early infection before antibodies develop may be missed by antibody testing.

Testing usually begins with an enzyme immunoassay that measures antibodies to Borrelia burgdorferi, sometimes including the C6 peptide. If that screen is positive or equivocal, a Western blot for IgM and IgG is commonly run to look for specific antibody bands. Some laboratories use a modified two-tier approach with different second-step assays.

The test is ordered when a person has symptoms that could fit Lyme disease and a history that makes it plausible, such as time spent in wooded or grassy areas where ticks live. A positive result does not by itself prove active infection, because antibodies can persist after treatment, and a negative result early in the illness may need to be repeated. A qualified healthcare provider interprets the findings.