Immunohistochemical detection of chlamydial antigens in association with cystitis

To investigate the etiologic role of Chlamydia trachomatis in cystitis, the authors used the immunoperoxidase technique with a monoclonal antibody against Chlamydia and examined paraffin sections from 36 cases of histologically proven cystitis. The average patients' age was 60 (range, 2-85) years. Biopsies were taken for follow-up of treated bladder carcinoma (19), hematuria (8), and other nonneoplastic conditions (9). Chlamydial antigens were detected by immunohistochemistry in 12 (33%) of these 36 cases. Staining for Chlamydia occurred in the upper layers of the transitional epithelium and involved long stretches of epithelium. Underlying inflammation was usually chronic but did not have specific distinguishing features. Eight of the Chlamydia-positive biopsies were taken for follow-up of treated carcinoma, two were for hematuria, one for neurogenic bladder, and one for evaluation of sterile pyuria. Eleven (92%) of these 12 positive cases had a history of recent urologic instrumentation, in contrast to only 11 (46%) of 24 negative cases (P less than 0.02). There was no significant difference in the age or sex distribution between the two groups. The authors conclude that Chlamydia trachomatis can ascend the urethra and infect the bladder urothelium. Urologic instrumentation enhances the ability of Chlamydia to reach the bladder. Chlamydia trachomatis may play an etiologic role in cystitis.