The role of urine cytology for 'decoy cells' as a screening tool in renal transplant recipients.
OBJECTIVE
To determine the role of urine cytology for 'decoy cells' as a screening tool for polyomavirus type BK (BKV) infection in renal transplant recipients.


METHODS
This was a prospective cohort study of patients undergoing renal transplantation between 2006 and 2010.


RESULTS
A total of 442 patients underwent urine cytology for decoy cells, 27.8% underwent 1 examination only and 72.2% more than one. Of the 1,713 examinations reviewed, 426 (24.9%) were positive and 785 (45.8%) were negative for 'decoy' cells, 380 (22.2%) showed degenerated tubular cells and 122 (7.1%) were unsatisfactory for analysis. Urine cytology was found to have a specificity of 68.5%, a sensitivity of 84.6%, a positive predictive value of 21.2%, a negative predictive value of 97.8% and an overall accuracy of 69.9%. The incidence of polyomavirus nephropathy among the patients investigated was 11.8%. Of the 442 patients, 32 (7.2%) had graft loss, which was attributed to BKV nephropathy in 2 (6.2% of the 32).


CONCLUSIONS
Urine cytology is an effective screening method for monitoring renal transplant patients, with high sensitivity and a high negative predictive value, and can therefore be used routinely in the follow-up of renal transplant patients.
Federal University of Health Sciences of Porto Alegre, Porto Alegre, Brazil.
Alana Durayski
AD
Ranzi
João Carlos
JC
Prolla
Elizete
E
Keitel
Rosicler
R
Brackmann
Roger
R
Kist
Giovana  Tavares
G
dos Santos
Claudia Giuliano
CG
Bica
D001739:BK Virus / Q000502:physiology; D003581:Cytodiagnosis / Q000379:methods; D005260:Female; D006801:Humans; D007674:Kidney Diseases / Q000175:diagnosis / Q000652:urine* / Q000821:virology; D016030:Kidney Transplantation / Q000009:adverse effects / Q000379:methods*; D008297:Male; D008403:Mass Screening / Q000379:methods; D027601:Polyomavirus Infections / Q000175:diagnosis / Q000652:urine* / Q000821:virology; D011183:Postoperative Complications / Q000175:diagnosis / Q000652:urine / Q000821:virology; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014412:Tumor Virus Infections / Q000175:diagnosis / Q000652:urine* / Q000821:virology