Screening for Polyomavirus Viruria Like Early Detection of Human Polyomavirus Infection and Replication: The Results of a Single-Center Observation

Abstract

Polyomavirus (PV) infection and PV-associated nephropathy (PVAN) are some of the most important problems in kidney transplantation. Our objective was to determine the incidence of PV viruria and PV replication in single-center Polish kidney transplant recipients (KTR). Urine samples from 155 cadaveric KTR were analyzed for PV viruria using quantitative real-time polymerase chain reaction and the patients were followed prospectively. The PV replication was recognized when the urine level was >107 PV DNA copies/mL of urine. Based on the PV DNA analysis, the patients were divided into 3 groups: Group 1 (n = 87; 56.1%) without viruria, Group 2 (n=44; 28.4%) with viruria but without PV replication, and Group 3 (n =24; 15.5%) with PV replication. The presence of PV viruria was correlated with the type of immunosuppressive regimen, strongly associated with tacrolimus intake. There was no correlation between viruria and mycophenolate daily dose in the study population. In Group 3 there were 6 patients (3.9%) with high viruria (>1010 copies/mL), and 5 patients from this group had confirmed PVAN in allograft biopsy. The prevalence of BK virus infection in KTR is similar to that reported in studies from other countries. We confirmed that PV viruria can be both a good screening for PV infection and a good predictor of PVAN. Tacrolimus was the most important predictor of PV viruria and PV replication in KTR.