Skip navigation | ||
|
||
Medical Encyclopedia |
|
Other encyclopedia topics: | A-Ag Ah-Ap Aq-Az B-Bk Bl-Bz C-Cg Ch-Co Cp-Cz D-Di Dj-Dz E-Ep Eq-Ez F G H-Hf Hg-Hz I-In Io-Iz J K L-Ln Lo-Lz M-Mf Mg-Mz N O P-Pl Pm-Pz Q R S-Sh Si-Sp Sq-Sz T-Tn To-Tz U V W X Y Z 0-9 |
Contents of this page: | |
|
|
|
|
|
|
Alternative names Return to top
Lyme disease serology; ELISA for Lyme disease; Western blot for Lyme diseaseDefinition Return to top
These tests are used to confirm the diagnosis of Lyme disease.How the test is performed Return to top
Blood is drawn from a vein on the inside of the elbow or the back of the hand. The puncture site is cleaned with antiseptic, and an elastic band is placed around the upper arm to apply pressure and restrict blood flow through the vein. This causes veins below the band to fill with blood.
A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. During the procedure, the band is removed to restore circulation. Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.
For an infant or young child, the area is cleansed with antiseptic and punctured with a sharp needle or a lancet. The blood may be collected in a pipette (small glass tube), on a slide, onto a test strip, or into a small container. Cotton or a bandage may be applied to the puncture site if there is any continued bleeding.
For the screening test, an ELISA is done as follows: the spirochete Borrelia burgdorferi, the causative organism of Lyme disease, is grown in culture and fixed to a microscope slide. The slide is then incubated with a sample of your serum (the portion of blood that contains antibodies). A fluorescent-labeled antiglobulin is placed on the slide and viewed under ultraviolet light. If human antibody to Lyme disease is present, it will bind to the fluorescent antiglobulin and be visible under the ultraviolet light.
A more specific test is a Western blot, where the specific antigen bands for Lyme disease are analyzed. This test is the true confirmation of Lyme disease.
How to prepare for the test Return to top
There is no special preparation for the test.How the test will feel Return to top
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.Why the test is performed Return to top
The test is performed to help confirm the diagnosis of Lyme disease.Normal Values Return to top
Nonreactive or a very low serum titer (antibody count) are normal.What abnormal results mean Return to top
A titer of 1:128 is borderline and further testing should be done. A positive serology by ELISA can help confirm the diagnosis of Lyme disease, but it is not definitive because other diseases and high rheumatoid factors can cause false positives. A Western blot can confirm the diagnosis of Lyme disease.What the risks are Return to top
The risks associated with having blood drawn are:
Special considerations Return to top
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. Update Date: 1/19/2004 Updated by: Daniel Levy, M.D., Ph.D., Infectious Diseases, Greater Baltimore Medical Center, Baltimore, MD. Review provided by VeriMed Healthcare Network.
Home | Health Topics | Drug Information | Encyclopedia | Dictionary | News | Directories | Other Resources | |
Copyright | Privacy | Accessibility | Selection Guidelines U.S. National Library of Medicine, 8600 Rockville Pike, Bethesda, MD 20894 National Institutes of Health | Department of Health & Human Services |
Page last updated: 28 October 2004 |