Effect of specific treatment on the evolution of antibody titers against Chlamydia trachomatis measured by the immunofluorescence and complement fixation tests

: We have evaluated the results of a serologic study of 34 patients with a possible chlamydial infection, obtaining three successive serum samples that were assessed with microimmunofluorescence (IIF) and complement fixation (CF) tests, so as to establish a comparison between the antibody titer measured by each of them. CF detects antibodies against the genus antigen, whereas IIF detects antibodies against the type-specific antigen. The antibodies against both antigens decrease in a parallel fashion, although somewhat more slowly in those against group antigen. This difference is significant (p less than 0.05).