Lupus erythematosus and reactive tests for syphilis: update.

Sera of patients with lupus erythematosus can produce false-positive reactions in most serologic tests for syphilis, including the FTA-ABS test. False-positive reactions in the FTA-ABS test can exhibit beaded, borderline or reactive patterns of fluorescence. Beaded fluorescence is commonly associated with anti-DNA antibody and other correlates of lupus activity. Borderline and reactive results are common in both systemic and discoid lupus erythematosus, and are usually not associated with increased clinical activity. TPI and MHA-TP tests appear helpful in detecting false-positive FTA-ABS results.