Borrelia Antibody (Blood)
Does this test have other names?
Borrelia burgdorferi antibodies test, IgM/IgG test, Lyme disease test
What is this test?
This test measures the level of Borrelia antibodies in your blood. Borrelia burgdorferi bacteria cause Lyme disease.
The bacteria are spread to humans through the bite of an infected tick.
If not treated, Lyme disease can cause meningitis, or an infection of the tissues covering the brain and spinal cord. It can also cause liver and heart problems; facial palsy, or the inability to control facial muscles; and other complications that may show up months or even years later. These include ongoing pain and tiredness, arthritis, and problems with memory and concentration. Lyme disease is the most common tick-borne condition in the U.S.
The CDC recommends a two-step evaluation of your blood test. First, your blood sample is tested through a process called enzyme immunoassay (EIA) or indirect immunofluorescence assay (IFA). If this is positive for Borrelia antibodies, the sample is put through an immunoblot test, also known as a Western blot test. This test measures immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies in your blood.
You will likely receive a positive diagnosis for Lyme disease if both the EIA/IFA and the Western blot test are positive. But in some cases, your doctor may order other tests, such as testing your cerebrospinal fluid.
Why do I need this test?
You might have this test if your doctor suspects that you have Lyme disease. Symptoms include a red bump that looks like a spider bite that spreads into a red rash in a classic bull's-eye pattern. You may also have:
Swollen lymph nodes
Muscle and joint aches
What other tests might I have along with this test?
Your doctor may also order a test to look for Borrelia antibodies in your cerebrospinal fluid if you have signs that your central nervous system has been affected. This may also be done if the blood test results aren't clear.
What do my test results mean?
Many things may affect your lab test results. These include the method each lab uses to do the test. Even if your test results are different from the normal value, you may not have a problem. To learn what the results mean for you, talk with your health care provider.
Normal results are negative, meaning that no antibodies were found. But Lyme disease is hard to diagnose, partly because the antibodies may not show up in your blood for several weeks. If your results are negative shortly after you've been infected, the result could be a false-negative.
A positive result means that Borrelia antibodies were found and that you may have Lyme disease. False-positive results aren't uncommon, though, so the test could say you have the infection when you don't.
False-positive results can also happen if you have the autoimmune disease lupus, HIV, or syphilis. They can also happen if you have Helicobacter pylori bacteria or the Epstein-Barr virus.
How is this test done?
The test requires a blood sample, which is drawn through a needle from a vein in your arm.
Does this test pose any risks?
Taking a blood sample with a needle carries risks that include bleeding, infection, bruising, or feeling dizzy. When the needle pricks your arm, you may feel a slight stinging sensation or pain. Afterward, the site may be slightly sore.
What might affect my test results?
The Lyme disease vaccine might affect your test results. If you are tested too soon after having been infected, you may get a false-negative result. If you have been treated with antibiotics, your results may be affected, too.
How do I get ready for this test?
You don't need to prepare for this test.