Detection of IgM antibodies against Chlamydia trachomatis by enzyme linked fluorescence immunoassay

A simple, sensitive enzyme linked fluorescence immunoassay has been developed to detect IgM antibodies against Chlamydia trachomatis. Reticulate bodies and elementary bodies from C trachomatis L2/434 Bu strain were isolated and used as antigens in the assay. Of 113 serum samples obtained from infants with pneumonia, 27 (23.9%) had IgM antibodies to C trachomatis L2 reticulate bodies and nine (8.0%) had IgM antibodies to C trachomatis L2 elementary bodies (titre greater than or equal to 1/500). Specific IgM antibodies were not detected in 20 control serum samples obtained from healthy adults and children. The possible use of enzyme linked fluorescence assay to determine IgM antibodies in the serodiagnosis of C trachomatis infection is discussed.