Haemagglutination test utilizing pathogenic Treponema pallidum for the sero-diagnosis of syphilis.

Haemagglutination reactions for the diagnosis of syphilis were first reported by Blumenthal (1932) and Bachmann (1932), who used an extract of syphilitic liver as the antigen. However, the test yielded both false positive and false negative reactions, rendering it of no diagnostic value. An agglutination test with suspensions of Reiter treponemes was used for testing cerebrospinal fluid by Roemer and Schlipkoter (1953). Lamedica and Robert (1957) tried a haemagglutination procedure to investigate the antibodies produced against the soluble Reiter protein antigen. They showed a fairly good correlation between the values of haemagglutination and complement-fixing tests with the same antigen. D'Alessandro (1958) attempted to sensitize human and sheep erythrocytes with lipopolysaccharide antigen from the Reiter treponemes without success. A haemagglutination test with erythrocytes conjugated with pathogenic treponemal antigen for the diagnosis of syphilis was first reported by Rathlev (1965). The present study summarizes results obtained from investigations on 300 human sera, including normal, syphilitic, and several non-treponemal or biological false positive specimens. This paper also reports the results of controlled animal experiments which show the correlation between the types of antibodies produced during the course of immunization, and the titres obtained in serological tests utilizing pathogenic treponemes as antigen.