FTA-ABS test
FTA-ABS stands for fluorescent treponemal antibody absorbed, a blood serum screening test for syphilis designed to demonstrate the presence or absence of specific antibodies directed against the organism (Treponema pallidum) responsible for syphilis.
FTA-ABS detects the majority but not all cases of the disease.
It is thus a way of screening for the disease.
A negative FTA-ABS test result is consistent with a person not having syphilis.
However, a person may have a negative FTA-ABS test result while in the early (primary) and late (tertiary) stages of the disease.
In the middle (secondary) stage of syphilis, the FTA-ABS test is most reliable and is reportedly positive in 100% of cases.
The FTA-ABS test is often used as a confirmatory test after first screening a patient with a VDRL (Venereal Disease Research Laboratory) or RPR (rapid plasma reagin) test, since the FTA-ABS test is more expensive and time-consuming than 'non-treponemal' syphilis tests such as the VDRL and RPR.