fluorescent treponemal antibody absorption test (FTA-ABS test), the standard treponemal antigen test for syphilis. Nonspecific antibodies are removed from patient serum, which is then reacted with Treponema pallidum fixed to a glass slide. Specific antibodies adhering to the treponemes are demonstrated with fluorescein-labeled antihuman globulin. Positive tests are seen in about 85% of cases of primary syphilis, 100% in secondary syphilis, and 98% in late syphilis. The test remains positive for life even after syphilis has been successfully treated. See also fluorescent antibody test.
