Association of Pretransplant BK Polyomavirus Antibody Status with BK Polyomavirus Infection After Kidney Transplantation: A Prospective Cohort Pilot Study of 47 Transplant Recipients

Background. Prevention and early detection of BK polyomavirus (BKV) infection is important for long-term kidney graft survival; hence, pretransplant screening methods are essential to identify recipients at high risk for BKV infection. This study investigated the association of pretransplant donor and recipient BKV antibody status with the occurrence of post-transplant BKV infection. Methods. We prospectively enrolled 47 adult living donor kidney transplant pairs from December 2014 to January 2016. Recipient and donor pretransplant BKV antibody titer was measured by hemagglutination inhibition (HI) test. Donor and recipient median HI titer of 1:20 was used as a cutoff to define seropositivity. Recipients were divided into 2 groups (BKV antibody donor-seropositive/recipient-seronegative (D+/R-) and non-D+/R-). Urinary cytology was used to screen for BKV infection. Plasma polymerase chain reaction testing for BKV DNA was used when decoy cells in urine were persistently detected. Results. Nine (19.2%) of 47 patients belonged to the Dthorn/R- group. Decoy cells were observed in 32 recipients (68.1%) during follow-up. BK viremia occurred in 3 (6.4%) cases. The maximum decoy cell count was significantly higher in the Dthorn/R- group than in the non-Dthorn/R- group (P = .0002). Decoy-cell-free survival was significantly shorter in the Dthorn/R- group (P = .0220). Multivariate analysis identified only BKV antibody serostatus as an independent risk factor for decoy cell appearance (P = .0491). Conclusions. Pretransplant donor and recipient BKV antibody status was associated with higher maximum decoy cell count and shorter decoy-cell-free survival after kidney transplantation.