The indirect enzyme-linked immunosorbent assay (ELISA) for detection of immunoglobulin M (IgM) antibodies to Treponema pallidum in sera of syphilitic patients is complicated by false positive reactions due to the interference of IgM rheumatoid factor (IgM-RF) activity and the presence of treponemal IgG antibodies. Another source of error producing false negative results is the competition between treponemal IgG and IgM antibodies for the binding sites on the antigen. To avoid these complications in the indirect Treponema pallidum-specific IgM-ELISA, total IgG was immunoprecipitated from sera of syphilitic patients prior to the assay. The IgM-RF from non-precipitated sera reacted in an IgM-RF-ELISA and in the Treponema pallidum-IgM-specific ELISA with identical titers. After precipitation of total IgG no reaction of the IgM-RF in the assay could be demonstrated. Competition between IgG and IgM antibodies can be prevented almost completely by the precipitation procedure. The sensitivity and specificity of the Treponema pallidum-specific IgM-ELISA after immunoprecipitation of total serum IgG were shown to be higher than 97 percent.

The role of lysozyme in the immune immobilisation of Treponerna pallidurn is not yet fully understood. The T. pallidurn immobilisation assay was used to demonstrate that the immobilisation and lysis of T. palliduin in vitro by antibodies (serum, IgG fraction or IgM fraction) and complement proceed in a lysozyme-independent mode. In the presence of lysozyme the rate of immobilisation increased. In contrast with its effect on Escherichia coli, the effect of lysozyme on T. pallidurn was governed exclusively by its enzymic activity rather than by the cationic protein nature of the molecule. Lysozyme, released from stimulated phagocytes, induced formation of lysozyme antibodies in 59.6% of syphilis patients as determined by lysozyme antibody ELISA. The highest frequency was found in patients with untreated secondary syphilis, whereas untreated primary syphilis was only rarely accompanied by the presence of lysozyme antibodies. Crossreactivities between lysozyme and treponemal antigens were excluded by immunoblotting. The autoantibodies did not influence the lysozyme activity. It was concluded that the formation of lysozyme antibodies is only an epiphenomenon in the host defence against treponemal infection.

The aim of the present study was to investigate the biological role of cardiolipin antibodies during Treponema pallidum infection. Inhibition of the binding of treponemal specific antibodies at the early and late stages of infection by cardiolipin antibodies was shown in the fluorescence treponemal antibody absorption (FTA-ABS) test and T.pallidurn immobilisation (TPI) test. Incubation of treponemes with cardiolipin antibodies followed by a second incubation with treponemal specific antibodies resulted in a reduction of the titres of the FTA-ABS test and the TPI test. The findings suggest that cardiolipin antibody production should be considered as a virulence mechanism of pathogenic treponemes with the purpose of evading the host defence mechanisms.

Zusammenfassung: In menschlichen Hautabstrichen konnte durch die PCR HSV-DNA nachgewiesen werden. Das untersuchte Material stammt von Hautl sionen eines Patienten mit diagnostiziertem Ewing-Sarkom. Um den Nachweis der amplifizierten DNA zu verbessern, wurde nach der PCR eine Hybridisierung mit einer spezifischen HSV-DNA-Sonde durchgef hrt. Die Herstellung der HSV-Sonde erfolgte durch die PCR unter Verwendung digoxigenierter Nukleotide. Schl sselw rter: Herpes simplex Virus -Polymerase Ketten-Reaktion -Digoxigeninmarkierte Sonde Summary: By using the polymerase chain reaction (PCR) an assay for HSV-DNA detection in human skin lesions was established. The material was extracted from skin lesions of a patient with Ewing sarcoma. To optimize the detection of the amplified DNA a hybridization was carried out with a specific HSV-DNA probe labeled by the PCR with a nonradioactive digoxigenin-deoxyuridinetriphosphate (dUTP).