Early clearance of BK polyomavirus-DNAemia among kidney transplant recipients may lead to better graft survival.

INTRODUCTION

BK polyomavirus (BKPyV)-DNAemia is a common complication in kidney transplant recipients (KTRs). The significance of achieving viral clearance at different time intervals is not well understood.

METHODS

All adult KTRs transplanted between January 1, 2015 and December 31, 2017 who developed BKPyV-DNAemia were included. Outcomes were analyzed based on persistent clearance of BKPyV-DNAemia at 3-month intervals up to 2 years after initial detection, and for recipients with persistent BKPyV-DNAemia at last follow-up. Uncensored graft failure, death-censored graft failure (DCGF), and a composite outcome of DCGF or fall in estimated glomerular filtration rate (eGFR) by ≥50% from the time of initial BKPyV-DNAemia were outcomes of interest.

RESULTS

Of 224 KTRs with BKPyV-DNAemia, 58 recipients (26%) achieved viral clearance by 3 months after initial detection, 105 (47%) by 6 months, 120 (54%) by 9 months, 141 (63%) by 12 months, 155 (69%) by 15 months, 167 (75%) by 18 months, 180 (80%) by 21 months, and 193 (86%) by 24 months. Nine recipients (4%) had persistent BKPyV-DNAemia at last follow-up. Compared to recipients who achieved viral clearance by 3 months, those who achieved clearance by 6 months (adjusted odds ratio [aOR]: 3.15; 95% confidence interval [CI]: 1.22-8.12; p = .02) and 9 months (aOR: 3.69; 95% CI: 1.02-13.43; p = .04) had significantly increased risk for uncensored graft failure. There was no significant association between time to viral clearance and DCGF or composite outcomes.

CONCLUSIONS

We found a trend of increased risk for uncensored graft failure among those who cleared BKPyV-DNAemia more slowly. Aiming to clear viremia early, without risking rejection, may be beneficial for allograft function and patient morbidity and mortality.