Characterizing the Impact of Induction Therapy on BK Polyoma Viral Reactivation: A Single-Center Analysis

Purpose: BKPyV following kidney transplantation is well recognized to cause premature graft failure and ureteral complications. Cumulative immunosuppression, including induction therapy, has a sustained impact on immune responses to opportunistic infection. We hypothesized that induction with cell-depleting agents affects the 1-year risk of BKPyV reactivation. Methods: Of 456 adult patients who underwent kidney transplants between January 2018 and February 2023 with at least 12 months of follow-up were screened for BK virus by blood PCR at 1.5, 3,6,9,12 months. Results: Among the 456 patients, 101 (22.1%) developed BKPyV viremia. The incidence of BKPyV positivity was highest with basiliximab (32%) compared to alemtuzumab (21%) and thymoglobulin (18%) (p = .032). Compared to basiliximab, receiving alemtuzumab (OR: 0.571, 95% CI: 0.329–0.991, p = .042) or thymoglobulin (OR: 0.462, 95% CI: 0.256-0.834, p = .010) was associated with a significantly lower risk of BKPyV. Higher KDPI was also significantly associated with an increased risk of BKPyV infection (OR: 1.120, 95% CI: 1.013–1.238, p = .026). Multivariable analysis showed a persistently significant lower risk of BKPyV infection with thymoglobulin (OR: 0.4, 95% CI: 0.21–0.75, p = .004) and alemtuzumab (OR: 0.5, 95% CI: 0.28–0.89, p = .019) compared to basiliximab. Also, higher KDPI was independently associated with BKPyV viremia (OR: 1.13, 95% CI: 1.01–1.25, p = .031). Conclusion: Induction therapy and higher KDPI were significant risk factors for BKPyV reactivation. Induction with cell-depleting agents lowered the risk of BKPyV, perhaps due to the subsequent use of lower maintenance immunosuppression and reduced need for acute rejection treatment.