Reduced urothelial expression of uroplakin-IIIa in cystitis areas in bladders of postmenopausal women with recurrent urinary tract infections: pilot study

Purpose: To study human bladder biopsies to investigate urothelial response to UTI, expression of uroplakin, and urothelial response after healing from cystoscopy with electrofulguration (CEF) treatment for antibiotic-recalcitrant RUTI.

Methods: Following IRB approval, cold cup bladder biopsies from "no cystitis" and "cystitis" regions were obtained from women with antibiotic-recalcitrant rUTI undergoing CEF under anesthesia. "No cystitis" and "cystitis" biopsies from 14 patients (5 had prior CEF, 9 naïve) were analyzed by immunofluorescence (IF) confocal microscopy using antibodies against uroplakin-IIIa. For an additional 6 patients (2 prior CEF, 4 naïve), only "cystitis" area biopsies were taken and analyzed. Cytokeratin 5 (marker for squamous metaplasia) staining was performed on 14 patients.

Results: In healthy tissue, uroplakin-IIIa staining was observed as a contiguous line on the luminal surface of umbrella cells. In "cystitis" areas for 19/20 patients, there was either no uroplakin-IIIa staining observed or spotty (+) staining. The "cystitis" regions of all patients had less intense uroplakin-IIIa staining compared to the matched "no cystitis" area in the same patient. In patients post-CEF but requiring repeat EF for persistent RUTI lesions, healed areas served as control and in 3 of 7 patients no uroplakin-IIIa staining was observed. Squamous metaplasia was observed in 10 patients.

Conclusion: In bladders of postmenopausal women with antibiotic-recalcitrant RUTI, areas with visible cystitis expressed less uroplakin-IIIa, supporting the model of urothelial exfoliation in response to UTI.