Comparative study of three assays for serum IgA against Chlamydia trachomatis

: This study was undertaken to evaluate the diagnostic value of detection and titration of specific IgA antibodies against Chlamydia trachomatis in active infections of the upper genital tract. Three different techniques using L2 serovar antigens were compared: immunofluorescence on cells infected with Chlamydia trachomatis, microimmunofluorescence as described by Wang and Grauston, and an indirect immunoperoxidase method on infected cells. Good correlations were found between the three techniques. Results demonstrated that the cutoff level should be 1/16.