Antibodies in secondary syphilis against five of forty Reiter treponeme antigens.

More than forty water-soluble antigens were found in the Reiter treponeme by crossed immunoelectrophoresis, using isolated and concentrated Ig from immunized rabbits. Five antigens reacted with antibodies in sera from selected patients with secondary syphilis, all having strong reactions in traditional tests for syphilis. No antibodies were found in selected healthy controls nonreactive in traditional syphilis tests. The five antigens represent available and potentially valuable antigens for development of new diagnostic syphilis tests. One of the antigens probably represents the axial filament. The findings open new possibilities for precise immunochemical studies of treponemes and of the immunology of syphilis.