Urine Cytology: Useful Screening Method for Polyoma Virus Nephropathy in Renal Transplant Patients

Polyoma virus nephropathy occurs in 3% to 4% of renal transplant recipients, causing graft loss in 50% of cases. The objective of the present study was to explore the effects of age, sex, post-transplantation period and plasma creatinine levels on the polyoma virus infection in kidney transplanted patients. Urine samples were collected from 362 patients, centrifuged and microscopic slides prepared using Papaniclaou staining method. The slides then examined and decoy cells were identified in 96 (27%) patients. The prevalence of the infection increased with increased post-transplantation period and the age of the patients. Moreover, patients with positive decoy cells had more abnormal plasma creatinine levels than those with negative for such cells. In conclusion identification of decoy cells might be of value for the diagnosis of nephropathy, especially if the presence of such cells is accompanied with the elevated plasma levels of creatinine. Iran J Med Sci 2006; 31(2): 109-111.