Urothelial Dysfunction and Chronic Inflammation are Associated With Increased Bladder Sensation in Patients With Chronic Renal Insufficiency

PURPOSE Chronic kidney disease (CKD) or end-stage renal disease (ESRD) patients usually have lower urinary tract symptoms, such as frequency and urgency. Additionally, they frequently suffer from urinary tract infections. This study investigated dysfunction and chronic inflammation of the bladder urothelium in ESRD/CKD patients. METHODS This study enrolled 27 patients with CKD (n=13) or ESRD (n=14) for urodynamic studies and bladder biopsies. Patients presented with detrusor underactivity (DU; n=8) or bladder oversensitivity (BO; n=19). Bladder biopsies were performed in these patients and in 20 controls. The bladder mucosa was examined for E-cadherin and zonula occludens-1 (ZO-1) expression, activated mast cell count (through tryptase staining), and urothelial apoptosis (through terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling [TUNEL]). The urodynamic parameters were also compared with variables regarding urothelial dysfunction. RESULTS The bladder mucosa samples of ESRD and CKD patients revealed significantly higher mast cell counts, more urothelial apoptosis, and lower levels of ZO-1 expression than the control samples. E-cadherin expression was significantly reduced in ESRD/CKD patients with DU, but not in ESRD/CKD patients with BO. Increased mast cell and apoptotic cell counts were also associated with ESRD/CKD with BO. Less expression of ZO-1 and E-cadherin was significantly associated with increased bladder sensation and a small bladder capacity. CONCLUSIONS Bladder urothelial dysfunction and chronic inflammation were present to a noteworthy extent in patients with ESRD or CKD. Increased inflammation and defective barrier function were more notable in ESRD/CKD bladders with BO than in those with DU. The clinical characteristics of these patients may involve urothelial pathophysiology.