title: Testing for polyomavirus type BK DNA in plasma to identify renal-allograft recipients with viral nephropathy.
abstract: BACKGROUND
  Reactivation of polyomavirus type BK (BK virus) is increasingly recognized as a cause of severe renal-allograft dysfunction. Currently, patients at risk for nephropathy due to infection with the BK virus are identified by the presence of cells containing viral inclusion bodies ("decoy cells") in the urine or by biopsy of allograft tissue.
  
  
  METHODS
  In a retrospective analysis, we performed polymerase-chain-reaction assays for BK virus DNA in plasma samples from 9 renal-allograft recipients with BK virus nephropathy; 41 renal-allograft recipients who did not have signs of nephropathy, 16 of whom had decoy cells in the urine; and as immunocompromised controls, 17 patients who had human immunodeficiency virus type 1 (HIV-1) infection (stage C3 according to the classification of the Centers for Disease Control and Prevention) and who had not undergone transplantation.
  
  
  RESULTS
  In all nine patients with BK virus nephropathy, BK virus DNA was detected in the plasma at the time of the initial histologic diagnosis (a mean [+/-SD] of 46+/-28 weeks after transplantation) and during the course of histologically diagnosed, persistent BK virus disease. In three of the six patients with nephropathy who were studied serially after transplantation, BK virus DNA was initially undetectable but was detected 16 to 33 weeks before nephropathy became clinically evident and was confirmed by biopsy. Tests for BK virus DNA in plasma became negative and the nephropathy resolved after the doses of immunosuppressive drugs were decreased in two patients and after removal of the renal allograft in three patients. BK virus DNA was found in the plasma of only 2 of the 41 renal-allograft recipients who had no signs of nephropathy and in none of the patients with HIV-1 infection.
  
  
  CONCLUSIONS
  Testing for BK virus DNA in plasma from renal-allograft recipients with use of the polymerase chain reaction is a sensitive and specific method for identifying viral nephropathy.
authors.affiliation: Institute for Pathology, University of Basel, Switzerland.
authors.forename: V
authors.initials: V
authors.lastname: Nickeleit
authors.forename: T
authors.initials: T
authors.lastname: Klimkait
authors.forename: I F
authors.initials: IF
authors.lastname: Binet
authors.forename: P
authors.initials: P
authors.lastname: Dalquen
authors.forename: V
authors.initials: V
authors.lastname: Del Zenero
authors.forename: G
authors.initials: G
authors.lastname: Thiel
authors.forename: M J
authors.initials: MJ
authors.lastname: Mihatsch
authors.forename: H H
authors.initials: HH
authors.lastname: Hirsch
mesh_terms: D001739:BK Virus / Q000235:genetics / Q000302:isolation & purification*; D004279:DNA, Viral / Q000097:blood*; D005260:Female; D006084:Graft Rejection / Q000821:virology; D006801:Humans; D007674:Kidney Diseases / Q000175:diagnosis / Q000821:virology*; D016030:Kidney Transplantation; D007684:Kidney Tubules / Q000473:pathology / Q000821:virology; D008297:Male; D016133:Polymerase Chain Reaction; D027601:Polyomavirus Infections / Q000175:diagnosis* / Q000821:virology; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014184:Transplantation, Homologous; D014412:Tumor Virus Infections / Q000175:diagnosis* / Q000821:virology
chemical_list: D004279:DNA, Viral