Risk factors for BK polyoma virus treatment and association of treatment with kidney transplant failure: Insights from a paired kidney analysis

Background. Identification of risk factors for BK polyoma virus (BKPyV) without confounding by donor factors and era effects in paired analysis may inform strategies to prevent BKPyV. Methods. In this analysis of 21,575 mate kidney pairs in the Scientific Registry of Transplant Recipients between 2004 and 2010, the presence of a treatment code for BKPyV virus in follow-up forms was used to identify pairs in which 1 of 2mate kidneys was treated (discordant treatment) or both mate kidneys were treated (concordant treatment). Results.Among 1975 discordant pairs, younger than 18 years or 60 years or older,male sex, HLA mismatch or 4 greater, acute rejection, and depleting antibody induction had a higher odds of treatment, whereas diabetes and sirolimus had a lower odds of treatment, and treatment was associated with a higher risk of allograft failure (hazards ratio, 2.01; 95% confidence interval, 1.63-2.48). The rate of concordant treatment (0.81%) was 2.8 times higher than expected. Concordant treatment was associated with nonwhite donor ethnicity, donation after circulatory death, transplantation after 2008, and transplantation of mate kidneys in the same center. Conclusions. This analysis of kidneys from the same donor in which only 1 transplant was treated for BKPyV identifies specific risk factors (age <18 or ≥ 60 years, male sex, depleting antibody, HLA mismatch ≥ 4) for BKPyV and provides an estimate of the BKPyV-associated risk of allograft failure (hazards ratio = 2.01) without confounding by donor factors or era effects. The higher than expected rate of concordant treatment suggests the importance of donor factors in BKPyV pathogenesis and warrants further study.