MICRONUCLEUS FREQUENCIES IN UROTHELIAL CELLS OF CATHETERIZED PATIENTSWITH CHRONIC BLADDER INFLAMMATION

Epidemiological studies suggest an association between chronic inflamm ation and increased risk for cancer, although the mechanism underlying this relationship is unresolved. In the present study, we test the hy pothesis that DNA damage is induced in the epithelium of tissues durin g such inflammation by products of activated inflammatory cells. Indiv iduals on long-term indwelling urinary catheterization were used as a study population. These individuals have chronic bladder inflammation and, as a population, an increased risk for bladder cancer. Urine of 2 9 patients and 26 age-matched non-catheterized controls was collected and micronucleus (MN) frequencies were determined in exfoliated urothe lial cells in the urinary sediments. The urine from the catheterized g roup had large numbers of white blood cells (mean count, 26.6 +/- 3.6 cells per high-power field), indicating the presence of a chronic blad der infection and an inflammatory reaction. In contrast, white blood c ells were not present in urine from individuals in the control group. There was no significant difference in MN frequencies in the 2 groups (mean frequencies, controls: 0.098 +/- 0.030%; catheterized: 0.140 +/- 0.025%, p = 0.13). These data imply that chromosomal damage does not always occur during chronic inflammation. Although the reasons for thi s observation are yet to be determined, possible explanations include the pathophysiology of the inflammatory reaction and the influence of vitamins, non-steroidal anti-inflammatory drugs and the catheter itsel f in protection against inflammatory cell-mediated DNA damage.