Leukocyturia in cyclosporine-treated renal allograft recipients

Five hundred eighty-seven daily urine specimens were examined from 179 consecutive renal allograft recipients with the use of quantitative cytodiagnostic urinalysis. Specimens were divided between those patients receiving cyclosporine (CyA) and steroid immunotherapy (73 patients) and those receiving standard azathioprine (Aza) and steroid immunotherapy (106 patients). When patients with urinary tract infections were excluded, an increase in leukocyturia was observed in the CyA-treated patients. Ninety-three percent of the CyA-treated patients had at least one specimen with more than 1,000 neutrophils/10 high-power fields (HPFs) versus 62% of the 106 Aza-treated patients. Sixty-four percent of the specimens examined from the CyA-treated group had more than 1,000 neutrophils/10 HPFs compared with only 18% of specimens from Aza-treated patients. It appears that CyA is a cause of sterile leukocyturia in renal allograft recipients. The significance of leukocyturia in CyA nephrotoxicity needs further definition.