[Influence of serum IgG antibodies to Chlamydia trachomatis on the functional activity of complement components].

ABSTRACT

The immunoenzyme analysis and the method for the determination of IgG-containing immune complexes, carrying C1q component of the complement, were developed. In human blood sera the functional activity of components C3, complex C1r2s2, the content of C1 inhibitor and complement-activating immune complexes were determined. The comparative analysis of the activity of components C3 and C1r2s2, as well as between the content of C1 inhibitor and the activity of complex C1r2s2 for seropositive and seronegative sera, was made. Pronounced correlation for seropositive sera was observed. In addition, for seropositive sera correlation between an increase in IgG immune complexes and a drop in the functional activity of complex C1r2s2, as well as a drop in the functional activity of complex C1r2s2 and a growth in the titers of IgG antibodies to Chlamydia trachomatis, were established. The decreased functional activity of key complement components, simultaneously with the presence of complement-activating immune complexes and high titers of specific antibodies could be the diagnostic criteria of carrier state.