Pilot Study of Early Monitoring Using Urinary Screening for BK Polyomavirus as a Strategy for Prevention of BKV Nephropathy in Kidney Transplantation.

Background: Urine monitoring programs represent an important strategy for early diagnosis of reactivation of BK polyomavirus (BKV) in kidney transplant recipients. This study analyzes a BKV urine screening model in kidney transplant patients.
Methods: Urinary screening for BKV reactivation was performed by urinary decoy cell and polymerase chain reaction (PCR) tests in samples from 32 consecutive kidney transplant patients, collected in a 6-month follow-up period. PCR in plasma samples and BKV immunohistochemical studies to assess BKV renal disease, if a kidney biopsy was indicated, were performed.
Results: The urinary screening for BKV among 32 renal receptors was positive in 18 patients (56%) by the concomitant use of the decoy cells and/or qualitative PCR at some time during the study period. Transfusion before transplantation was significantly associated with urinary decoy cell positive screening (odds ratio = 11; 95% confidence interval = 1.47 to 82.4; P < .05); and so was male sex (odds ratio = 2.02; 95% confidence interval = 1.07 to 3.83; P < .05). The clinical management of screening positive cases consisted of decreasing or changing the immunosuppression regimen. Sixteen renal biopsies were performed. Immunohistochemistry for SV40 T antigen was negative in all biopsies. After 1 year of follow-up, no patient developed BKV-associated nephropathy, and there was no difference in renal function between patients positive and negative for BKV urinary screening.
Conclusions: Early urinary monitoring is effective in detection of BKV replication and represents a good strategy to minimize the deleterious effects caused by the presence of the virus on preservation of graft function.
(Copyright © 2016 Elsevier Inc. All rights reserved.)