Ureteral stent placement and immediate graft function are associated with increased risk of BK viremia in the first year after kidney transplantation

Ureteral stent (UrSt) placement has been shown to be a significant independent risk factor for BK viruria, viremia and BK virus nephropathy. We assessed if this observation could be validated at our high volume kidney transplant center that has had a strong historical focus on BK virus nephropathy detection. We performed a retrospective case-control study of adults receiving a kidney-only transplant and followed for one year between 2004 and 2011 with uniform immunosuppression and use of blood BK virus PCR screening protocol. Among 1147 patients, 443 (38.6%) received a UrSt, and 17.2% with a UrSt had BK viremia versus 13.5% without stent (odds ratio 1.33; 95% CI 1.00-1.78). We confirmed a previously reported association between immediate graft function (IGF) and higher rate of BK viremia (15.7% versus 5.9% in patients without IGF). On multivariable competing risks Cox regression in patients with IGF, UrSt (adjusted hazard ratio [aHR] 1.35;95% CI 1.04-1.75) and African-American race (aHR 1.47;95% CI 1.04-2.09) significantly increased the risk for BK viremia. In the largest sample size to date, we confirmed that UrSt placement during kidney transplant surgery is a risk factor for BK viremia within the first year post-transplant and that IGF is associated with BK viremia. This article is protected by copyright. All rights reserved.