Influence of cardiolipin antibodies on the binding of treponemal specific antibodies in the fluorescence treponemal antibody absorption test and the Treponema pallidum immobilisation test

The aim of the present study was to investigate the biological role of cardiolipin antibodies during Treponema pallidum infection. Inhibition of the binding of treponemal specific antibodies at the early and late stages of infection by cardiolipin antibodies was shown in the fluorescence treponemal antibody absorption (FTA-ABS) test and T. pallidum immobilisation (TPI) test. Incubation of treponemes with cardiolipin antibodies followed by a second incubation with treponemal specific antibodies resulted in a reduction of the titres of the FTA-ABS test and the TPI test. The findings suggest that cardiolipin antibody production should be considered as a virulence mechanism of pathogenic treponemes with the purpose of evading the host defence mechanisms.