Purpose of review: BK virus is one of the most frequent causes of graft loss after renal transplantation, with BK virus-associated nephropathy occurring in roughly 8% of patients, and graft loss rates reported as high as 50%. This review is meant to highlight the literature on BK viral disease following renal transplantation published in the most recent year.
Recent findings: Prevention of BK virus-associated graft loss requires early diagnosis of BK viral replication, which is best achieved by screening for BK viral DNA in the blood. Screening intervals more frequently than the currently recommended 3 months appear to offer increased efficacy. Reduction in immunosuppression remains the mainstay for treatment of BK viral disease, with consideration given to antiviral drug therapy with leflunomide. Acute rejection may be minimized by a short course of intravenous immunoglobulin. Sirolimus appears to be a promising addition to the therapeutic armamentarium. For patients requiring re-transplantation after BK virus-associated graft loss, viral clearance from the bloodstream prior to re-transplantation should be achieved to attain optimal results.
Summary: BK virus is a major pathogen affecting renal allografts, although intensive surveillance and targeted dose reduction in immunosuppression with the consideration of additional antiviral drug therapy can minimize graft loss resulting from infection.