title: A qualitative seminested PCR assay as an alternative to urine cytology for BK polyomavirus screening after renal transplantation.
abstract: OBJECTIVE
  Polyomavirus-associated nephropathy (PVAN) is a major cause of graft dysfunction after kidney transplantation. Therefore, routine screening for BK polyomavirus (BKV) infection with urine cytology or quantitative PCR-based assays has been recommended. Although less expensive than quantitative tests, qualitative PCR assays are not recommended for screening based on the assumption that their diagnostic accuracy is inferior to urine cytology. However, studies comparing the performance of both methods are scarce.
  
  
  METHODS
  We compared the accuracy between a qualitative seminested PCR (snPCR) assay and urine cytology for the screening of BKV viruria in 104 renal transplant recipients.
  
  
  RESULTS
  The snPCR assay was more sensitive than cytology (100 and 61%, respectively), yielding better negative predictive value (100 vs. 90%). In 7 (39%) of the 18 PVAN cases, BKV infection was detected exclusively by snPCR. Although the specificity of snPCR (63%) was lower than cytology (74%), their positive predictive values were similar (36 vs. 33%, respectively). In ROC curve analysis, the accuracy of snPCR was significantly higher (p = 0.03).
  
  
  CONCLUSIONS
  This qualitative snPCR assay was more accurate than urine cytology for the detection of BKV viruria in renal transplant patients.
authors: Department of Preventive Medicine, Faculdade de Medicina, Universidade Federal do Rio de Janeiro, Brazil.
authors: Ana Carolina Jonard
authors: AC
authors: Zalona
authors: Rafael Brandão
authors: RB
authors: Varella
authors: Cristina Maeda
authors: CM
authors: Takiya
authors: Renato Torres
authors: RT
authors: Goncalves
authors: Mariano Gustavo
authors: MG
authors: Zalis
authors: Guilherme
authors: G
authors: Santoro-Lopes
mesh_terms: D001739:BK Virus / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D016030:Kidney Transplantation; D008403:Mass Screening / Q000379:methods; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D016133:Polymerase Chain Reaction / Q000379:methods*; D027601:Polyomavirus Infections / Q000175:diagnosis* / Q000821:virology; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D014556:Urine / Q000166:cytology / Q000821:virology*; D014773:Virology / Q000379:methods*