BK virus infection and its effect on renal function in pediatric liver-transplant recipients: A cross-sectional, longitudinal, prospective study

Background. Chronic renal failure (CRF) is a well-documented complication of liver transplantation. BK virus (BKV) is a common cause of CRF in renal-transplant recipients and has been sporadically associated with renal failure after nonrenal solid-organ transplantation. The aims of the study were to determine the prevalence of BK viruria and viremia in pediatric liver-transplant recipients, assess the natural course of BKV infection over time, and examine the association between BKV positivity and renal function. Methods. A prospective, cross-sectional study of 59 pediatric liver-transplant recipients. Blood and urine samples were collected at enrollment for creatinine level and BKV polymerase chain reaction test. BKV-positive patients underwent repeated testing and follow-up. The medical files were reviewed for clinical data. Results. Median age at enrollment was 11.5 years, and median time from transplantation was 61 months. One child (1.7%) had viremia, and nine children (15.3%) had viruria (median: 610 copies/mL). All cases of viruria/viremia resolved spontaneously, nine of them within 10 months. There were no significant differences in demographic or clinical variables between the BKV-positive and BKV-negative children. None of the BKV-positive patients had evidence of renal dysfunction. Conclusion. Pediatric liver-transplant recipients have a low prevalence of BK viruria/viremia. BKV infection is associated with low viral loads and resolves spontaneously within a relatively short period, without residua. BKV is not associated with CRF postliver transplantation. BKV testing should not be part of the routine follow-up of children after liver transplantation.