BK Polyomavirus Nephropathy in Renal Allografts

Abstract

Introduction: BK polyomavirus (BKPyV) causes nephropathy in 1–10% of kidney transplant recipients, leading to graft loss. Methods: Systematic review of 40 studies on screening, diagnosis, and management of BKPyV nephropathy. Results: Routine plasma BKPyV PCR screening every 1–3 months detects viremia in 10–30%. Reduction of immunosuppression (first step: decrease calcineurin inhibitor or antimetabolite) cleared viremia in 70% without acute rejection. Cidofovir and leflunomide have limited efficacy. Discussion: Screening-guided immunosuppression reduction is the standard of care. Graft biopsy shows viral inclusions and interstitial nephritis. Conclusion: Regular BKPyV screening and proactive immunosuppression reduction prevent graft loss.