BERKELEY, CA (UroToday Inc.) - Interstitial cystitis (IC) is an enigmatic disease, which remains a diagnosis of exclusion. Glomerulations following bladder hydrodistention are considered to be a finding consistent with IC. How or why glomerulations occur in patients with IC is not clear. Therefore Tamaki and colleagues, based on their previous studies that showed angiogenic growth factors are increased in IC bladders, examined the possibility that the expression of angiogenic growth factors may correlate with the cystoscopic presence of glomerulations.

They performed cystoscopic evaluation and hydrodistention on 45 patients with suspected IC. These patients suffered from refractory frequency and bladder pain that lasted greater than 6 months and underwent a thorough evaluation to rule out any other pathologic conditions. After hydrodistention, bladder biopsies were taken from the areas with glomerulations. The tissue was then analyzed using enzyme-linked immunosorbent assay (ELISA) and immunohistochemical staining to measure the expression of the two angiogenic growth factors platelet derived endothelial cell growth factor/thymidine phosphorylase (PDECGF/TP) and vascular endothelial growth factor (VEGF).

Their results were reported in the September 2004 edition of the Journal of Urology. Of the 45 patients undergoing hydrodistention, 38 (33 women and 5 males) had cystoscopic findings of glomerulations. The seven who had no glomerulations as well as five asymptomatic patients were used as controls. Symptomatic patients with glomerulations had significantly higher PDECGF/TP expression than symptomatic patients without glomerulations or asymptomatic patients. Immunohistochemical staining was positive for PDEFCGF/TP in 97.4% and VEGF in 68.4% in those with glomerulations, while none of the asymptomatic patients stained positively.

In conclusion, there appears to be an increased expression of angiogenic growth factors in patients with IC typified by glomerulations. These growth factors may promote neovascularization and contribute to bleeding of glomerulations during hydrodistention.

J Urol 2004; 172:945-948