Polyomavirus BK Replication in Adult Polycystic Kidney Disease Post-Renal Transplant Patients and Possible Role of Cellular Permissivity

Cell division and differentiation but not proliferation seem to be necessary for BK virus (BKV) replication and reactivation of persistent infection. Only terminal differentiating cells are permissive to BKV replication. Renal tubular epithelial cells in human adult polycystic kidney disease (ADPKD) are characterized by increased proliferative activity leading to cyst growth with less cellular differentiation. The aim of this study was to evaluate the possibility of different BKV replication patterns in patients with polycystic kidney disease versus non-ADPKD patients. From May 2006 to April 2008, we performed renal transplantations in 47. Eleven patients were affected by ADPKD (Pc group) and 36 patients, non ADPKD (n-Pc group). BKV replication was evaluated by quantitative real-time polymerase chain reactions (PCR) on plasma and urine samples at 12 hours (T0/early) as well as 3 (T3) and 6 (T6) months after transplantation. BKV viremia occurred in 9%, 12.5%, and 20% among the Pc group versus 33.3%, 42.4%, and 50% among the n-Pc group at 12 hours as well as 3 and 6 months posttransplantation, respectively. A higher discordance (BKV-PCR blood -/urine +) was observed in plasma and urine BKV replication among Pc versus n-Pc groups. We hypothesized that the lower number of patients with active BKV plasma replication in the Pc group may be related to a lower cellular permissivity of the renal tubular epithelial cells in ADPKD.