[Technical advances in demonstration of treponema-specific 19S-IgM antibodies in patients with latent or late-latent syphilis (author's transl)].

In patients with latent or late-latent syphilis as well as neurosyphilis the demonstration of treponema-specific 19S-IgM antibodies is not regularly possible. In this publication it is shown that high IgG antibodies are the reason for a competitive IgM inhibition in the indirect immunofluorescence tests. It is demonstrated that in the above mentioned states of the infection the IgM-FTA-19S test seemed to be the method of choice to realize the existence of 19S-IgM antibodies. In sera with competitive inhibited IgM it is possible to calculate the IgM antibody activity with the aid of the socalled F factor.