Characterization of Kidney Retransplantation Following Graft Failure Due to BK Virus Nephropathy.

INTRODUCTION

Immunosuppression following kidney transplantation increases risk of BK polyomavirus reactivation, a common cause of graft dysfunction and failure. Subsequent retransplantation is a viable option that has not been extensively studied. This study further characterizes BK Virus Nephropathy (BKVN) and retransplantation in the most expansive population to date, geographically, temporally, and in magnitude.

MATERIALS AND METHODS

The OPTN/UNOS database was used to identify patients who received kidney or kidney-pancreas transplantation between 1987 and 2018 that resulted in BKVN-attributed failure (n = 1587). This population was divided into those who underwent retransplantation (n = 495) and those who did not (n = 1092).

RESULTS

The retransplanted cohort was younger (45 vs. 53 yr; P<0.0001) and had fewer prior kidney transplants (P<0.003), lower expected post-transplant survival (P<0.001), lower rates of delayed graft function (DGF) (14.1% vs. 22.2%; P=0.0008), a greater proportion of white patients (55.4% vs. 43.2%; P=0.0002), a greater proportion of living donors (35.8% vs. 23.0%; P<0.0001), and longer allograft lifespan (2.95 vs. 2.41 yr; P<0.0001), compared to those not retransplanted. Among retransplants, DGF and high kidney donor profile index (KDPI) were associated with decreased allograft lifespan (P=0.001, P=0.0005, respectively). Steroid induction had no effect on allograft lifespan when compared to steroid-free regimens (P=0.915). Retransplanted allografts lasted longer than previous BKVN-failed grafts (10.44 and 3.70 years, respectively; P<0.0001).

CONCLUSIONS

Retransplantation following BKVN-associated graft failure has been associated with favorable outcomes. To maximize allograft lifespan in retransplantation, clinicians may consider selection of low KDPI donors, prevention of delayed graft function, and tailored immunosuppressive regimens that minimize steroids.