title: Screening for polyomavirus associated nephropathy in renal transplantation with blood viral load measurement.
abstract: BACKGROUND
  Polyomavirus associated nephropathy (PVAN) is an important cause of graft failure in the renal transplant population. It has been shown that viremia precedes PVAN, suggesting that measurement of blood viral load could be used for PVAN screening.
  
  
  OBJECTIVE
  To verify the utility of BK virus (BKV) blood viral load measurement for PVAN screening in the renal transplant population, establish a threshold value, and determine the sensitivity and specificity of the test.
  
  
  METHODS
  We developed a real-time PCR assay for BKV blood viral load measurement and included this assay in the PVAN screening protocol of the renal transplant recipients of our institution. We report results for 60 patients who had a blood viral load measurement concomitantly with an allograft biopsy with immunohistochemistry for polyomavirus.
  
  
  RESULTS
  14 patients were found to have a PVAN on allograft biopsy together with a viral load above 3.0x10(3)copies/ml. None of the patients with a viral load under 3.0x10(3)copies/ml had a PVAN on allograft biopsy. The area under the receiver operating characteristic (ROC) curve was 0.95 (95% CI: 0.91-1.00) and using a threshold value of 3.0x10(3)copies/ml yielded a sensitivity of 100% (95% CI: 76.8-100%) and a specificity of 89.6% (95% CI: 77.3-96.5%) for PVAN screening.
  
  
  CONCLUSIONS
  BKV blood viral load measurement is sensitive and specific for PVAN screening when a threshold value is precisely determined.
authors: Microbiology Laboratory, Hôtel-Dieu de Québec hospital, Centre Hospitalier Universitaire de Québec, 11, Côte du palais, Québec, Canada, G1R 2J6. alexandre.boudreault.1@ulaval.ca
authors: Alexandre A
authors: AA
authors: Boudreault
authors: Chantal
authors: C
authors: Courtemanche
authors: Eva
authors: E
authors: Latulippe
authors: Isabelle
authors: I
authors: Côté
authors: Isabelle
authors: I
authors: Houde
authors: Louise
authors: L
authors: Deschênes
mesh_terms: D001739:BK Virus / Q000302:isolation & purification*; D001769:Blood / Q000821:virology; D006801:Humans; D007674:Kidney Diseases / Q000175:diagnosis* / Q000821:virology; D016030:Kidney Transplantation / Q000009:adverse effects*; D008403:Mass Screening / Q000379:methods*; D016133:Polymerase Chain Reaction / Q000379:methods*; D027601:Polyomavirus Infections / Q000175:diagnosis* / Q000821:virology; D012680:Sensitivity and Specificity; D019562:Viral Load / Q000379:methods*; D014766:Viremia / Q000175:diagnosis