ELISA inhibition test using monoclonal antibody specific for Treponema pallidum as the serologic test for syphilis.

Monoclonal antibodies (Mabs) specific for Treponema pallidum were produced using hybridoma technology. In this study an ELISA inhibition test based on competitive inhibition by antibodies from human test sera of the binding of the enzyme-labelled Mabs to T. pallidum was performed. Inhibition of the seroreactivity of Mabs was decreased according to the dilution of rabbit antiserum to T. pallidum. Seropositivity was found in 100% of secondary and early latent syphilis patients, 75% of primary syphilis patients, and 80% of late latent syphilis patients. The mean percentage inhibition was significantly higher in each syphilis group than in the controls, and statistically significant differences were shown between all the syphilis groups. VDRL and TPHA titers were correlated with the percentage inhibitions. Therefore the ELISA inhibition test using Mab specific for T. pallidum might well be a suitable tool as a new serologic test for syphilis.