Spontaneous reversion of FTA-ABS test reactions.

In a series of 56 clinically healthy persons with no history of syphilis and negative VDRL tests but reactive fluorescent treponemal antibody absorption (FTA-ABS) tests, 20 spontaneously developed nonreactive FTA-ABS tests in a period of eight months or less. All but one of these had been of 2+ or less fluorescence. In such a situation, the serologic tests for syphilis (VDRL and FTA-ABS tests) should be repeated at intervals for up to a year before coming to a decision regarding the diagnosis of syphilis. Laboratories could facilitate that decision by reporting degrees of fluorescence of the FTA-ABS test.