THE APPEARANCE AND PERSISTENCE OF VDRL, RPCF, AND TPI ANTIBODY DURING THE COURSE AND TREATMENT OF EXPERIMENTAL SYPHILIS IN THE RABBIT

[摘要] The VDRL, Reiter protein complement fixation, (RPCF), and Treponema pallidum immobilization (TPI) titers of 15 rabbits were deter-mined following intratesticular infection with 4.2 X 106 virulent T. pallidum, Nichols strain, and treatment 24 weeks later with 1.2 million units of benzathine penicillin G (Bicillin). Two weeks after infection, each of 8 rabbits tested had developed RPCF antibodies. Three of these animals exhibited non-reactive VDRL tests, 6 had still failed to develop TPI antibody, and 4 showed reactive VDRL and non-reactive TPI tests. Seven of 13 animals tested at varying intervals after pinicillin therapy exhibited non-reactive TPI and reactive RPCF tests at some time during the 48 weeks following treatment. Reagin, as measured by the VDRL procedure, was demonstrable in only one instance. The results suggest that non-reactive TPI and reactive or weakly reactive RPCF tests may occur in treated latent human syphilis. The accuracy of its reactivity confirms the value of the RPCF test when employed in the triple test plan for serologic diagnosis.