A deficit of chondroitin sulfate proteoglycans on the bladder uroepithelium in interstitial cystitis

Objectives. To investigate the abundance of chondroitin sulfate proteoglycans at the bladder lumenal and subepithelial surfaces in bladder biopsies derived from patients with interstitial cystitis (IC) and controls. Methods. Tissue sections derived from biopsies from 31 IC patients and 24 pathologically normal control sections were labeled for proteoglycans using the 2B6 anti-'stub' antibody and detected by immunohistochemistry. Results. On the lumenal surface, 5 of 31 (19%) IC sections were positive for proteoglycans versus 14 of 24 (58%) control sections (P = 0.00011). At the basal surface, 5 of 19 IC patients were positive versus 7 of 12 controls (P = 0.032). Conclusions. A deficit of bladder lumenal and basal proteoglycans is associated with IC. The deficit in basal layer proteoglycans suggests an altered urothelial differentiation program. The lumenal deficit suggests that the charge-dependent exclusion of ions from the bladder surface is compromised in IC.