Detection of BK polyomavirus genotypes to predict the development of BK polyomavirus‐associated complications in kidney transplant recipients: A retrospective analysis

<jats:title>Abstract</jats:title><jats:sec><jats:title>Objectives</jats:title><jats:p>This study focused on the role that BK polyomavirus (BKPyV) genotypes can play in the development of BKPyV‐associated complications in renal transplant recipients.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>A retrospective observational study (January 2015 to April 2018) was conducted by analyzing BKPyV genotypes in 180 blood samples with detectable BKPyV viral load (VL) > 1000 copies/mL, from 63 renal transplant recipients. VL and BKPyV genotypes detections were based on real‐time PCR (rt‐PCR)‐specific assays.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>Forty‐four patients (44/63 [69.8%]) were men, and the median age was 55.0 (interquartile range 49.0‐66.0 years). Eleven patients had clinical manifestations (11/63 [17.5%]). The most frequently detected genotypes were I (14/63 [22.2%]) and II (13/63 [20.6%]). Half of the patients (33/63 [52.4%]) had a mixed genotype, most with genotypes I and II (25/33 [75.8%]). Patients with infection by mixed genotypes showed VLs that were detected earlier (in the first year after transplantation) than those with a single genotype (25/33 [75.8%] vs 13/30 [43.3%], <jats:italic>P</jats:italic> = .009) and demonstrated greater risk of developing clinical manifestations associated with BKPyV (odds ratio 12.609, 95% confidence interval 1.503‐105.807). Moreover, patients with first BKPyV VL > 10 000 copies/mL more frequently presented mixed genotypes (12/16 [75.0%] vs 21/47 [44.7%], <jats:italic>P</jats:italic> = .036).</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>The probability of developing clinical manifestations is higher in infections by mixed genotypes. Therefore, the detection of BKPyV genotypes by rt‐PCR can provide relevant information to stratify patients' risk of BKPyV‐associated complications and guide the clinical management of BKPyV infection in kidney transplant recipients.</jats:p></jats:sec>