title: Clinical impact of BK virus surveillance on outcomes in kidney transplant recipients.
abstract: BACKGROUND
  The objective of this study was to investigate the clinical impact of BK virus surveillance on graft injury in kidney transplantation.
  
  
  METHODS
  BK viremia in kidney transplant recipients was evaluated by use of plasma quantitative polymerase chain reaction. The prevalence of BK viremia and BK virus-associated nephropathy (BKVAN) and the clinical impact of BK viremia on graft outcomes were assessed.
  
  
  RESULTS
  This study took place between January 2008 and June 2013. A total of 213 kidney transplant recipients were included. The prevalence of BK viremia and high BK viremia (≥1 × 10(4) copies/mL) was 66.7% (142/213) and 17.4% (37/213), respectively. A diagnosis of BKVAN was confirmed by means of allograft biopsy in 9 patients (4.2%). The estimated glomerular filtration rate after transplantation was similar in both the low BK viremia (<1 × 10(4) copies/mL) and non-BK viremia groups but was significantly lower in the high BK viremia group after 18 months. In receiver operating characteristic curve analysis, the area under the curve value of plasma polymerase chain reaction was 0.980. We found that a viral load >92,850 copies/mL was able to predict BKVAN with 89% sensitivity and 94.6% specificity. The risk factors for viral loads ≥1 × 10(4) copies/mL were cytomegalovirus infection, steroid pulse therapy, and acute rejection.
  
  
  CONCLUSIONS
  High BK viremia was associated with poor graft function after kidney transplantation. The serial monitoring of BK viremia in kidney transplant recipients was helpful in predicting BKVAN and might prevent further progression.
authors.affiliation: Department of Internal Medicine, Konyang University Hospital, Daejeon, Korea.
authors.forename: S-H
authors.initials: SH
authors.lastname: Yoon
authors.affiliation: Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu, Korea.
authors.forename: J-H
authors.initials: JH
authors.lastname: Cho
authors.affiliation: Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu, Korea.
authors.forename: H-Y
authors.initials: HY
authors.lastname: Jung
authors.affiliation: Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu, Korea.
authors.forename: J-Y
authors.initials: JY
authors.lastname: Choi
authors.affiliation: Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu, Korea.
authors.forename: S-H
authors.initials: SH
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu, Korea.
authors.forename: Y-L
authors.initials: YL
authors.lastname: Kim
authors.affiliation: Department of Surgery, Kyungpook National University School of Medicine, Daegu, Korea.
authors.forename: H-K
authors.initials: HK
authors.lastname: Kim
authors.affiliation: Department of Surgery, Kyungpook National University School of Medicine, Daegu, Korea.
authors.forename: S
authors.initials: S
authors.lastname: Huh
authors.affiliation: Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu, Korea. Electronic address: drcdkim@knu.ac.kr.
authors.forename: C-D
authors.initials: CD
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D001739:BK Virus / Q000302:isolation & purification*; D005260:Female; D006801:Humans; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D027601:Polyomavirus Infections / Q000175:diagnosis* / Q000453:epidemiology / Q000209:etiology; D011183:Postoperative Complications / Q000175:diagnosis* / Q000453:epidemiology; D015995:Prevalence; D012372:ROC Curve; D012680:Sensitivity and Specificity; D014184:Transplantation, Homologous; D014412:Tumor Virus Infections / Q000175:diagnosis* / Q000453:epidemiology / Q000209:etiology; D014766:Viremia / Q000175:diagnosis* / Q000453:epidemiology / Q000209:etiology