Involvement of the urinary bladder in systemic lupus erythematosus. A pathologic study

Urinary bladder histologic changes were found in 16 of 35 necropsies from systemic lupus erythematosus (SLE) patients in whom adequate material was available for study. These included interstitial cystitis (n = 11), hemorrhage (n = 9), congestion (n = 7), vasculitis (n = 5), and perivenular infiltrate (n = 4). Abnormalities were found in only 5 of 30 control necropsies from patients with other diseases and in 4 of them these were hemorrhagic and chiefly due to indwelling catheters. SLE patients with histologic bladder changes were found to have pulmonary hemorrhage more frequently than those without. This suggests a common pathogenetic mechanism between interstitial cystitis and pulmonary hemorrhage in SLE.