URINE CITOLOGY AS A SCREENING MEHTHOD FOR POLIOMAVIRUS INFECTION IN A GROUP OF STABLE RENAL TRANSPLANT RECIPIENTS IN BRAZIL

Abstract

P825 Aims: Polyomavirus nephropathy (PVN) occurs in 3 to 4% of the renal transplants, causing graft loss in about 50% of the cases. Presence of viral cytopathic changes in epithelial cells of the graft is the only diagnostic tool for PVN. However, identification of cells with viral inclusions (decoy cells) in urine can be used as a screening for viral replication, or active infection for PV. The aim of the present study was to identify the occurrence of PV active infection in stable renal transplant recipients. Methods: Two hundred and forty urine cytology samples, collected from 80 transplant patients with stable renal function were analyzed. Urine samples were collected in a monthly basis, and urine cytology stained with Papanicolau (for decoy cells). Active infection for Polyomavirus was confirmed by urine immunostaining. All the samples were analyzed blinded and classified in negative and positive (>1 decoy cell/sample). Results: From 240 urine cytologies, collected from 48 male and 32 female transplant patients, decoy cells were identified in 37.5%. No differences were observed in serum creatinine or imunossupressive regimen between patients with positive or negative cytology. Blood PCR in patients with positive citology was positive in 60% of the cases. In some patients, despite of the persistence of positve citology, PCR become negative after imunnossuppressive adjustment. No graft loss secondary to PVN occurred in the present setting. Conclusions: The incidence of decoy cells in this series (37.5%) is coincident with previous reports (20% to 40%), suggesting active infection, that was confirmed by PV immnunohistochemistry. The absence of PVN in this group can be attributed to the low doses of immunossupressive drugs in the late post transplant period, and negativation of blood PCR, but also to the unknown incidence of polyomavirus infection in Brazil.