The classification of different phenotypes of interstitial cystitis/ bladder pain syndrome (IC/BPS) provides different pathophysiology and associated treatment strategies. Most clinical studies have focused on bladder symptoms and cystoscopic findings. This study analyzed bladder wall thickness (BWT) and compared bladder conditions, urinary biomarkers, and histopathology among patients of IC/BPS with different BWT.

A total of 182 patients with cystoscopy-proven IC/BPS underwent abdominal computed tomography (CT) before intervention. The BWT on CT was classified as smooth, focal thickness, and diffuse thickness. Clinical symptoms, urodynamic findings, cystoscopic characteristics, presence of Hunner’s lesion, urinary biomarkers, and bladder histopathology were compared among the three subgroups.

Among the patients, 85 had smooth, 64 had focal, and 33 had diffuse BWT. There was a significant trend of patients with focal and diffuse BWT being significantly older with higher symptom scores, smaller bladder capacity, higher grade of glomerulations, and incidence of Hunner’s IC. Pathological findings revealed that patients with diffused BWT, followed by those with focal thickness, had the greatest uroepithelial cell denudation and plasma cell infiltration. Patients with diffuse BWT has higher rate of inflammatory cell infiltration, nerve bundle hyperplasia, and granulation tissue. The urinary levels of tumor necrosis factor-alpha and oxidative stress biomarkers in IC/BPS patients with different BWT were significantly higher than those in the controls.

BWT in CT scans can reflect chronic inflammation of the bladder wall in patients with IC/BPS, which is clinically relevant for the diagnosis and treatment of IC subtypes.