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.