Immune complexes in experimental T. pallidum infection in rabbits.

The polyethylene glycol precipitation method can be used to detect immune complexes in the sera of rabbits experimentally infected with Treponema pallidum. Immune complexes are present in the serum of rabbits infected either intravenously or intratesticularly and only when syphilitic lesions were present. Immune complexes were not observed in the serum of rabbits infected intradermally with T. pallidum.