Histological evidence supports low anesthetic bladder capacity as a marker of a bladder-centric disease subtype in interstitial cystitis/bladder pain syndrome

• Published in: International Urogynecology Journal Vol. 30; no. 11; pp. 1863 - 1870
• Main Authors: Schachar, Jeffrey S., Evans, Robert J., Parks, Graham E., Zambon, Joao, Badlani, Gopal, Walker, Stephen J.
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.11.2019; Springer Nature B.V
• Subjects: Adult; Aged; Anesthetics - pharmacology; Biomarkers; Biopsy; Bladder; Cystitis, Interstitial - classification; Cystitis, Interstitial - diagnosis; Cystitis, Interstitial - physiopathology; Female; Gene expression; Genotype & phenotype; Gynecology; Humans; Inflammation; Male; Medicine; Medicine & Public Health; Middle Aged; Original Article; Pain; Pathology; Patients; Retrospective Studies; Urinary Bladder - drug effects; Urinary Bladder - pathology; Urinary Bladder - physiopathology; Urogenital system; Urology; Histology; Bladder capacity; Subtype; Interstitial cystitis; Bladder pain syndrome
• ISSN: 0937-3462; 1433-3023; 1433-3023
• DOI: 10.1007/s00192-019-04038-0

Introduction and hypothesis Low anesthetic bladder capacity has been shown to be a biomarker for bladder-centric interstitial cystitis/bladder pain syndrome (IC/BPS). The goal of this study was to determine if histopathological evidence from bladder biopsies supports anesthetic bladder capacity (BC) as a marker to distinguish a bladder-centric IC/BPS subtype. Methods From a review of our large IC/BPS cohort of patients undergoing hydrodistention, we identified a total of 41 patients with low BC (≤ 400 ml); an additional 41 consecutive patients with BC > 400 ml were selected as the comparator group. The original bladder mucosal biopsy pathology slides were re-reviewed by a single pathologist (blinded to patient information) using a standardized grading scale developed for this study. Results Histologically, the low BC subjects exhibited higher levels of acute inflammation ( p  = 0.0299), chronic inflammation ( p  = 0.0139), and erosion on microscopy ( p  = 0.0155); however, there was no significant difference in mast cell count between groups ( p  = 0.4431). There was no significant gender difference between the groups; female patients were the majority in both groups (low BC: 94.12%, non-low BC: 100%; p  = 0.1246). Individuals in the low BC group were older ( p  < 0.0001), had a higher incidence of Hunner’s lesions on cystoscopy ( p  < 0.0001), and had significantly higher scores, i.e., more bother symptoms, on two IC/BPS questionnaires (ICPI, p  = 0.0154; ICSI, p  = 0.0005). Conclusions IC/BPS patients with low anesthetic bladder capacity have histological evidence of significantly more acute and chronic inflammation compared with patients with a non-low bladder capacity. These data provide additional evidence to support low bladder capacity as a marker of a distinct bladder-centric IC/BPS phenotype.