Detection of nephrotoxicity in cyclosporine-A amyotrophic lateral sclerosis patients by means of urinary cytology

Exfoliative urinary cytology was used for two amyotrophic lateral sclerosis patients treated with 3 mg/kg/day cyclosporine (CsA) therapy in order to detect the onset of the nephrotoxic side-effects of the drug before the apparent deterioration of the patients' clinical condition. Of the two patients, only one showed clear morphological features of drug-related damage in a one year course of cyclosporine therapy, but these followed the increase in the serum kidney and liver laboratory parameters and did not prove useful for the early detection of nephrotoxicity. However, in this patient the renal damage was hallmarked by an increasing number of tubular cells or clusters of ill-defined renal cells in the urinary specimen, suggesting an ongoing tubular injury. The slight cytological alterations may possibly be due to the low CsA dosage used for these patients. The significance of these observations is tempered by the limited number of patients and specimens studied to date and further studies in non-transplanted patients are therefore advocated, particularly when higher CsA doses are employed.