Clinical Relevance of Bladder Histopathological Findings and Their Impact on Treatment Outcomes among Patients with Interstitial Cystitis/Bladder Pain Syndrome: An Investigation of the European Society for the Study of Interstitial Cystitis Histopathological Classification.

PURPOSE: We investigate the clinical significance of European Society for the Study of Interstitial Cystitis (ESSIC) bladder histopathological classification and its impact on treatment outcomes among patients with interstitial cystitis/bladder pain syndrome.

MATERIALS AND METHODS: Bladder biopsy specimens obtained from severe, treatment refractory interstitial cystitis/bladder pain syndrome cases were analyzed by a single pathologist blinded to clinical data. Inflammatory cell infiltration and urothelium denudation, eosinophil infiltration, plasma cell infiltration, lamina propria hemorrhage and granulation in specimens were evaluated separately. Patients with at least 1 histopathological finding were classified as ESSIC type C, with the rest being classified as ESSIC type A. Current overall treatment outcomes were determined via telephone interview.

RESULTS: Bladder specimens were obtained from 352 patients with interstitial cystitis/bladder pain syndrome. Bladder inflammation, urothelium denudation, eosinophil and plasma cell infiltration, lamina propria hemorrhage and granulation were present in 69.6%, 44.6%, 9.1%, 15.3%, 4.8% and 5.1% of the bladder specimens, respectively. Approximately 78.7% of the patients included were ESSIC type C and had a smaller cystometric bladder capacity and higher bladder pain compared to ESSIC type A. Although individual histopathological findings were not associated with treatment outcome, a higher proportion of ESSIC type A patients had worse, unchanged or less than 25% improvement outcomes compared to ESSIC type C (43.1% vs 25.8%, p=0.025).

CONCLUSIONS: Bladder histopathological findings were associated with clinical parameters and differences in patient reported treatment outcomes. Accordingly, patients with interstitial cystitis/bladder pain syndrome who had no remarkable bladder histopathological findings had less favorable treatment outcomes compared to those who did.