Lyme disease antibody tests are used to help diagnose Lyme disease.

Blood is typically drawn from a vein, usually from the inside of the elbow or the back of the hand. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.

Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm.

Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

In infants or young children, a sharp tool called a lancet may be used to puncture the skin and make it bleed. The blood collects into a small glass tube called a pipette, or onto a slide or test strip. A bandage may be placed over the area if there is any bleeding.

The laboratory specialist will look for Lyme disease antibodies in the blood sample using the ELISA test. If the ELISA test is positive, it must be confirmed with the Western blot test.

There is no special preparation for the test.

When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.

The test is performed to help confirm the diagnosis of Lyme disease.

Nonreactive or a very low serum titer (antibody count) is normal. This is called a negative result. If the ELISA test is negative, no other testing needs to be done most of the time.

Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

An abnormal ELISA result must be followed up with a Western blot test. Only a positive Western blot test can confirm the diagnosis of Lyme disease.

For many people, the ELISA test remains positive even after they have been treated and no longer have symptoms.

A positive ELISA can help confirm the diagnosis, but it isn't enough by itself. Other diseases, such as rheumatoid arthritis can give the same results.

In some patients, early treatment with antibiotics can cause the antibody test to be negative.

Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight, but may include:

• Excessive bleeding
• Fainting or feeling light-headed
• Hematoma (blood accumulating under the skin)
• Infection (a slight risk any time the skin is broken)

Halperin JJ, Shapiro ED, Logigian E, Belman AL, Dotevall L, Wormser GP, et al. Practice parameter: treatment of nervous system Lyme disease (an evidence-based review): report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology. 2007 Jul 3;69(1):91-102. Epub 2007 May 23.

Wormser GP, Dattwyler RJ, Shapiro ED, Halperin JJ, Steere AC, Klempner MS, et al. The clinical assessment, treatment, and prevention of Lyme disease, human granulocytic anaplasmosis, and babesiosis: clinical practice guidelines by the Infectious Diseases Society of America. Clin Infect Dis. 2006 Nov 1;43(9):1089-134.