The role of treponemal and nontreponemal tests in the serodiagnosis of syphilis is reviewed. Diagnostic problem cases should be evaluated by treponemal tests to distinguish latent syphilis from false-positive reactions. A comparison of treponemal tests performed on serum from 101 late latent and tertiary syphilitics showed that the fluorescent treponemal antibody absorption (FTA-ABS) test is more sensitive than the Treponema pallidum immobilization (TPI) or FTA-200 tests. Objective evidence of late syphilis was present in 6 of 11 patients with discordant test results (TPI nonreactive; FTA-ABS reactive).
Of the 50 chronic false-positive reactors studied, 24 had evidence of lupus erythematosus or another of the autoimmune diseases.