title: BK virus infection and its effect on renal function in pediatric liver-transplant recipients: a cross-sectional, longitudinal, prospective study.
abstract: 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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Pediatrics B, Schneider Children's Medical Center of Israel, Petach Tikva, Israel.
authors.forename: Achiya
authors.initials: A
authors.lastname: Amir
authors.forename: Rivka
authors.initials: R
authors.lastname: Shapiro
authors.forename: Lester M
authors.initials: LM
authors.lastname: Shulman
authors.forename: Eytan
authors.initials: E
authors.lastname: Mor
authors.forename: Ran
authors.initials: R
authors.lastname: Steinberg
authors.forename: Hava
authors.initials: H
authors.lastname: Fleishhacker
authors.forename: Rachel
authors.initials: R
authors.lastname: Bergerin
authors.forename: Yaron
authors.initials: Y
authors.lastname: Avitzur
mesh_terms: D000293:Adolescent; D000328:Adult; D001739:BK Virus; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007223:Infant; D016031:Liver Transplantation / Q000009:adverse effects*; D008137:Longitudinal Studies; D008297:Male; D027601:Polyomavirus Infections / Q000453:epidemiology*; D015995:Prevalence; D011446:Prospective Studies; D014412:Tumor Virus Infections / Q000453:epidemiology*; D014766:Viremia / Q000453:epidemiology