Bladder Tissue Study Reveals Key Differences Between Hunner IC and Non-Hunner IC
Jhang JF, Hsu YH, Kuo HC. Urothelial Functional Protein and Sensory Receptors in Patients with Interstitial Cystitis/Bladder Pain Syndrome with and Without Hunner’s Lesion. Urology. 2016 Aug 26. pii: S0090-4295(16)30542-8. doi: 10.1016/j.urology.2016.08.029. [Epub ahead of print]
In this study, investigators looked for very closely at bladder tissue from interstitial cystitis (IC) patients to ascertain differences between Hunner IC and non-Hunner IC at the cellular level. Hunner IC is the less common variant of IC, but can be associated with more severe symptoms. To test for differences, the researchers obtained biopsies of the bladder mucous membrane from 14 female IC/BPS patients with Hunner’s lesion and 14 without Hunner’s lesion. As might be expected, the Hunner IC patients had significantly higher pain scores and smaller bladder capacity compared to the non-Hunner IC patients. However, they also found that the Hunner IC bladder specimens more often showed moderate to severe infiltration of eosinophils, a type of white blood cell often associated with inflammation; additionally, the bladder tissue from the Hunner IC patients more often showed denudation, or a loss of protective surface layers. There were also differences noted in expression of a protein called E-cadherin, and notably, expression of enzyme called endothelial nitric oxide synthase (or e-NOS) was significantly higher in the Hunner IC bladder samples. The researchers think that, in particular, this difference in e-NOS expression may be a key underlying factor that may influence whether an individual develops the Hunner or non-Hunner variety of IC.