Cytodiagnosis of Chlamydia trachomatis by the immunoperoxidase technic

The PAP-immunocytochemistry using a monoclonal antibody against Chlamydia trachomatis was applied to male patients with clinically manifest urethritis and their female sex partners. In addition, serum levels of the antibody were determined by means of an ELISA system. Immunoperoxidase reactions were recognized on urethral scrapes in 53 (33%) out of 160 cases, and on endocervical specimens in 13 (59%) out of 22 sex partners of PAP-positive patients. In patients with gonococcal urethritis, an infection of C. trachomatis was revealed immunocytochemically in 11 (31%) out of 36 cases, and in 29 (46%) out of 62 cases with non-gonococcal urethritis. Following medication with 200 mg of minocycline or doxycycline per day, PAP staining became negative in 23 (66%) out of 35 cases. The levels of serum antibody against C. trachomatis were undetectable in 8 (26%) out of 29 PAP-positive cases, but positive in 7 (15%) out of 44 PAP-negative cases.