Objectives: To examine the correlation among bladder inflammation, angiogenesis, fibrosis and urothelial denudation in biopsied bladder specimens, and O'Leary-Sant symptom indexes, O'Leary-Sant problem indexes and visual analog scale pain scores in interstitial cystitis/bladder pain syndrome patients with or without Hunner lesions (Hunner type interstitial cystitis or non-Hunner type interstitial cystitis).

Methods: Bladder biopsied tissues were collected from 12 Hunner type interstitial cystitis female patients, 12 non-Hunner type interstitial cystitis female patients and 12 age-matched non-interstitial cystitis female patients (controls). Immunohistochemical stainings of tissue necrotic factor-α, mast cell tryptase, vascular endothelial growth factor, CD31, transforming growth factor-β, SLUG associated with epithelial mesenchymal transition and E-cadherin as well as Masson trichrome staining were evaluated. The significant correlation between the expression of tissue necrotic factor-α, mast cell tryptase, vascular endothelial growth factor, CD31, transforming growth factor-β, collagen, SLUG or E-cadherin, and O'Leary-Sant symptom indexes, O'Leary-Sant problem indexes or visual analog scale pain scores was then examined.

Results: The expression of tissue necrotic factor-α, vascular endothelial growth factor, CD31, transforming growth factor-β and SLUG was significantly increased in non-Hunner type interstitial cystitis and Hunner type interstitial cystitis patients compared with controls whereas the significant increases in the expression of mast cell tryptase and collagen were observed in Hunner type interstitial cystitis patients compared with controls and non-Hunner type interstitial cystitis patients. On the other hand, the expression of E-cadherin was significantly decreased in Hunner type interstitial cystitis patients compared with controls and non-Hunner type interstitial cystitis patients. In addition, the increased expression of CD31 in bladder tissues was strongly correlated with O'Leary-Sant symptom indexes, O'Leary-Sant problem indexes and visual analog scale pain scores.

Conclusions: These results suggest that bladder angiogenesis evident as the increased expression of CD31 is strongly correlated with urinary frequency and bladder pain in patients with non-Hunner type interstitial cystitis and Hunner type interstitial cystitis.