Purpose: To determine whether an antiproliferative urine factor that we previously discovered to be specific for urine from interstitial cystitis (IC) patients originated in the lower urinary tract or a more proximal site.
Materials and methods: Sequential catheterized urine specimens were collected under sterile conditions from the bladder and renal pelvis of 20 IC patients and one control patient (with stress incontinence). Antiproliferative activity was determined by 3H-thymidine incorporation of primary normal adult bladder epithelial cells cultured with pH- and osmolality-corrected bladder or ureteral urine specimens; significant inhibition was defined as a change in 3H-thymidine incorporation greater than 2 standard deviations from the mean of control cells.
Results: Bladder urine specimens from 19 of 20 IC patients significantly inhibited 3H-thymidine incorporation as compared to cell medium alone (mean change for bladder specimens = -68.7+/-7.5%), while a renal pelvic specimen from only 1 of 20 IC patients inhibited proliferation significantly (mean change for renal pelvic specimens = 3.2+/-3.4%) (p<.001 by Fisher's exact test). The one inhibitory IC renal pelvic specimen inhibited by 31% while a bladder specimen obtained during the same procedure inhibited by 94%. In comparison, neither bladder nor renal pelvic urine from the control patient had inhibitory activity.
Conclusions: The antiproliferative factor previously found in the urine of IC patients appears to be made and/or activated in the distal ureter or urinary bladder.