title: Detection of polyomavirus BK reactivation after renal transplantation using an intensive decoy cell surveillance program is cost-effective.
abstract: BACKGROUND
  Reactivation of polyomavirus BK (BKV) after renal transplantation can lead to allograft dysfunction or loss with early detection improving outcomes. Current guidelines recommend quantitative polymerase chain reaction for surveillance; however, urinary decoy cell detection is a potentially cost-effective alternative. We present the outcomes from an early intensive BKV surveillance program using decoy cell detection for initial screening starting 2 weeks after transplantation.
  
  
  METHODS
  Records for all recipients of kidney (n=211) or simultaneous kidney and pancreas (n=102) transplants performed over 2 years in a single center were reviewed. Follow-up was for a minimum of 1 year. Urine cytology screening was performed fortnightly from 0 to 3 months after transplantation, monthly from 3 to 6 months then every 2 months from 6 to 12 months.
  
  
  RESULTS
  Decoy cell positivity occurred in 56 of 313 patients (17.9%) with sustained decoy cell positivity (≥2 positive urine samples >2 weeks apart) present in 32 patients (10.2%). Twenty-four patients (7.6%) became viremic and three patients (1%) developed polyoma virus nephropathy. The median time after transplantation until decoy cell positivity was 78 days, decreasing to 67 days for patients with sustained positivity and 57 days for patients who developed polyoma virus nephropathy. No grafts were lost due to BKV during the study period. Decoy cell screening resulted in savings of approximately £135,000 over 2 years, when compared with routine surveillance by quantitative polymerase chain reaction.
  
  
  CONCLUSIONS
  Clinically significant BKV reactivation occurs early after transplantation and can be reliably detected by decoy cell screening. A surveillance strategy for detecting BKV reactivation based on urine cytology is cost-effective.
authors.affiliation: Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK. aron.chakera@ndm.ox.ac.uk
authors.forename: Aron
authors.initials: A
authors.lastname: Chakera
authors.forename: Oliver-James
authors.initials: OJ
authors.lastname: Dyar
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Hughes
authors.forename: Sophia
authors.initials: S
authors.lastname: Bennett
authors.forename: David
authors.initials: D
authors.lastname: Hughes
authors.forename: Ian S D
authors.initials: IS
authors.lastname: Roberts
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001739:BK Virus / Q000302:isolation & purification*; D002648:Child; D002675:Child, Preschool; D003362:Cost-Benefit Analysis; D003584:Cytological Techniques / Q000191:economics* / Q000379:methods; D005500:Follow-Up Studies; D006084:Graft Rejection / Q000209:etiology / Q000821:virology; D006801:Humans; D007165:Immunosuppression Therapy; D007223:Infant; D016030:Kidney Transplantation / Q000276:immunology; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D027601:Polyomavirus Infections / Q000150:complications / Q000175:diagnosis* / Q000652:urine; D012189:Retrospective Studies; D014184:Transplantation, Homologous; D014412:Tumor Virus Infections / Q000150:complications / Q000175:diagnosis* / Q000652:urine; D014556:Urine / Q000166:cytology* / Q000821:virology*; D055815:Young Adult