Development and characterization of highly informative ELISA for the detection of IgG and IgA antibodies to Сhlamydia trachomatis

The goal of this work was developing of highly informative an enzyme-linked immunosorbent assay (ELISA) for the detection of IgG and IgA antibodies against to Chlamydia trachomatis, as well as comparative characterization of developed assay using standardized control materials. The study was conducted using: monoclonal antibodies (McAbs) to human IgA and IgG; recombinant Ch. trachomatis proteins – Pgp3, major outer membrane protein (MOMP); two panels of characterized sera and four reference ELISA kits. The study of immunochemical activity of peroxidase conjugates of McAbs was performed in comparison with conjugates of commercial analogues: anti-IgG McAb 2A11 and anti-IgA McAb AD3. About half of the conjugates from the received McAbs panel were more active compared to the reference antibody conjugates. It was quite justified to use the conjugates of antibodies that interact with different antigenic determinants. When IgG antibodies were detected to MOMP, it was justified 1.14-1.56 times more; when IgA antibodies were detected to MOMP, it was justified 1.16-1.37 times more. ELISA for detecting IgG/IgA antibodies to MOMP and Pgp3 of Ch. trachomatis were evaluated using appropriately described serum panels OCO-42-28-313-00 and OCO-42-28-314-00. Comparative studies of the developed ELISA for the detection of IgG and IgA antibodies to the MOMP and Pgp3 of Ch. trachomatis showed their prominent advantage over the commercial analogues, which more clearly demonstrates the difference in the ratio of average values of optical density of positive and negative samples of the described panel of sera: this indicator for commercial kits was 1.36-3.59 times less