Abstract
BACKGROUND AND OBJECTIVE: BK polyomavirus (BKPyV) poses a significant challenge in kidney transplant (KTX) recipients, potentially leading to BKPyV-associated nephropathy. Prophylactic ureteral stent (UrSt) placement is the standard care following KTX. Emerging data suggest that UrSt may influence the incidence and severity of BKPyV-DNAemia. We hypothesized a dose-dependent relationship between an indwelling UrSt and the risk of BKPyV-DNAemia in KTX recipients. METHODS: We included all KTX recipients with detectable BKPyV-DNAemia at the Medical University of Vienna from 2010 to 2021; those without DNAemia served as controls. This nested, retrospective, 1:1 sex- and age-matched case-control study assessed whether UrSt placement and/or its duration was associated with BKPyV. KEY FINDINGS AND LIMITATIONS: Of 438 KTX recipients, 51.6% of viremic patients had received UrSt, compared with 47% of nonviremic controls. While UrSt placement was not associated with the risk of BKPyV-DNAemia (odds ratio [OR] 1.20, 95% confidence interval [CI] 0.83-1.75), indwelling time of >8 wk was (OR 1.79, 95% CI 1.10-2.93, p = 0.02). In a multivariable analysis, it remained an independent predictor of BKPyV-DNAemia (adjusted OR 1.74, 95% CI 1.06-2.86, p = 0.03). Limitations include the retrospective, single-center study design. CONCLUSIONS AND CLINICAL IMPLICATIONS: Prophylactic UrSt placement after KTX does not increase the risk of developing BKPyV-DNAemia. However, the indwelling time of the UrSt should be limited to <8 wk to reduce the risk of BKPyV-DNAemia. Therefore, early removal of UrSt-preferably within 8 wk-should be pursued when clinically feasible. Further research is needed to define the optimal UrSt indwelling time and clarify the underlying pathophysiological mechanisms. PATIENT SUMMARY: In this study, we examined whether the placement and duration of ureteral stents after kidney transplantation affect the risk of developing a BK polyomavirus that can harm the transplanted organ. We found that the length of time the stent remains in place-especially beyond 8 weeks-was linked to a higher risk of viral reactivation. Removal of the stent earlier may help protect patients from these complications.