Urothelial Dysfunction and Increased Suburothelial Inflammation of Urinary Bladder Are Involved in Patients with Upper Urinary Tract Urolithiasis – Clinical and Immunohistochemistry Study

OBJECTIVES To investigate the urothelial dysfunction and inflammation of urinary bladder in patients with upper urinary tract (UUT) urolithiasis through the results of cystoscopic hydrodistension and immunohistochemistry study. METHODS Ninety-one patients with UUT urolithiasis underwent cystoscopic hydrodistension before the stone surgery. Immunofluorescence staining of E-cadherin, zonula occludens-1 (ZO-1), tryptase (mast cell activation), and TUNEL (urothelial apoptosis) were performed in 42 patients with glomerulations after hydrodistension, 10 without glomerulations, and 10 controls. RESULTS Of the 91 patients, 62 (68.2%) developed glomerulations after hydrodistension. Lower urinary tract symptoms (LUTS) were present in 53.8% patients, in whom significantly smaller maximal anesthetic bladder capacity (MBC) was noted. Patients with middle or lower 1/3 ureteral stones had a significantly higher glomerulation rate (88.6% vs. 55.4%, p<0.01) and lower MBC (618.4 ± 167.6 vs. 701.2 ± 158.4 ml, p = 0.027) than those with upper 1/3 ureteral or renal stones. Patients with UUT urolithiasis had significantly lower expression of E-cadherin (26.2 ± 14.8 vs. 42.4 ± 16.7) and ZO-1 (5.16 ± 4.02 vs. 11.02 ± 5.66); and higher suburothelial mast cell (13.3 ± 6.8 vs. 1.3 ± 1.2) and apoptotic cell (2.6 ± 2.5 vs. 0.1 ± 0.3) numbers than in controls (all p<0.01). CONCLUSIONS Urothelial dysfunction and increased suburothelial inflammation and apoptosis are highly prevalent in the bladders of UUT urolithiasis patients, indicating inflammation cross-talk between UUT and urinary bladder. Patients with UUT urolithiaisis concomitant with LUTS had a smaller MBC, which may explain the presence of irritative bladder symptoms.