If you are a sexually active individual or have a risk for syphilis, this blood test can be an important tool to help protect your health. It measures antibodies, or proteins, that signal a syphilis infection by targeting the bacteria Treponema pallidum. The FTA-ABS, or Fluorescent Treponemal Antibody Absorption Test, is often used in combination with a nontreponemal test (like the VDRL or RPR) to confirm that there is a true infection.
There is no need to fast before this test. It is recommended that you take your prescription medications as directed by your doctor. This can include avoiding any medication that is likely to interfere with the test results.
During the FTA-ABS, your blood is tested using fluorescent labeling to detect antibodies directed against the treponema pallidum bacteria. The treponemal antibody is detected with a specific antigen conjugated to fluorescein, and the resulting antigen-antibody complex is visualized by the addition of peroxidase. A positive result indicates the presence of Treponema pallidum antibodies and a previous or current syphilis infection.
A positive test result will remain positive for life, even if syphilis treatment has been completed and no active disease is present. Other infections such as yaws and pinta may also cause a false positive test result, as can certain diseases like lupus.
The test is performed on a blood sample that is sent to the laboratory for analysis. Depending on the lab that performs your test, the results can be available within 10 to 14 days of collection.