The fluorescent treponemal antibody absorption (FTA-ABS) test is a blood test that checks for the presence of antibodies to Treponema pallidum bacteria which causes Syphilis. Syphilis is a sexually transmitted infection (STI) that's spread through direct contact with syphilitic sores, these sores are most often present on the penis, vagina or rectum. The FTA-ABS test is often performed after other tests that screen for syphilis, such as the rapid plasma regain (RPR) and venereal disease research laboratory (VDRL) tests. The ABS suffix refers particularly to a processing step used to remove nonspecific anti spirochetal antibodies present in normal serum.
The Fluorescent Treponemal Antibody Absorption test doesn’t require any special preparations. It is very essential for the doctor to ensure that the patient is not under any kind of over-the-counter medications or any other type of herbal medicines. The doctor should also enquire If the patient is taking any kind of blood thinners such as Warfarin or Coumadin. Therefore,the doctor should advise the patient to take any kind of medicines that can affect the test results. The patient should be given sufficient information about the blood test and must get them ready for the same.
A normal test result will give a negative reading for the presence of antibodies to T. pallidum bacteria. This means that the patient is not currently infected with syphilis and that he/she have never been infected with the disease. An abnormal test result will give a positive reading for the presence of antibodies to T. pallidum bacteria. This means that the patient has or has had a syphilis infection. The test result will also be positive even if the patient has been previously diagnosed with syphilis and it was treated successfully. In rare cases, you may receive a false positive test result for syphilis.This means that the patient doesn’t have Syphilis but may have diseases such as Yaws and Pinta.
Serum from patients suspected of having syphilis because of previous positive VDRL or RPR test is diluted in 1:5 sorbent. The absorbed serum is layered on a microscope slide which contains fixed T. pallidum subspecies pallidum. If the patient’s serum contains antibody, the antibody will coat the treponema. Later,fluorescein isothiocyanate (FITC)-labeled anti human immunoglobulin is added which combines with the patient’s IgG and IgM antibodies that are adhering to T. pallidum, and results in a visible test reaction when examined by fluorescence microscopy. FTA-ABS test should not be used as a primary screening procedure.