Clinical Implications of Polyomavirus-Associated Nephropathy after Renal Transplantation.
Helen P Cathro, Jason C Gardenier, Costi D Sifri, Douglas S Keith, Robert G Sawyer, Kenneth L Brayman, Hugo Bonatti. University of Virginia, Charlottesville; Vanderbilt University, Nashville, TN
Background: BK virus nephropathy (BKVN) develops in ∼5% of renal transplants (RT), causing graft loss in 15-80% of cases within 5 years. Most studies suggest that the majority of BKVN occurs during the first post-transplant (PT) year. We noticed an increasing number of cases of late-onset BKVN and conducted a retrospective study.
Design: All renal specimens from patients with biopsy-proven BKVN from 2000-2009 at a single institution were reviewed.
Results: Of 846 RT recipients, 18 had biopsy-proven BKVN (2.1%), 4 of whom had also received pancreatic transplants. The median age of 12 males and 6 females was 52.2 yr (range 27.9-63.8 yr), and the median time PT was 20.1 mn (range 3.2-80.4 mn), with only 4 or 22%, <1 yr out. Fourteen patients were on standard immunosuppression (IS). Screening for BK virus was erratically administered due to geographical/logistical constraints. Five patients had prior biopsy proven episodes of acute rejection and 13 patients (72%) had received intensive prior IS, usually for acute rejection (n=10) or for subsequent pancreas transplantation. Fourteen patients were treated with antiviral therapy, +/- IVIG, +/- IS taper, and single patients were treated with IVIG or IS taper alone. One patient died after returning to dialysis, and 17 were alive at an average of 3.4 yr follow up. Seven of these had returned to dialysis (41%), and 5 had a serum creatinine >2 mg/dL (29%). Only 5 patients had good graft function (29%).
Conclusions: Retrospective analysis of BKVN at a single institution during the current IS era demonstrated 78% of cases occurring after the first PT year, and 39% after the second PT year. Inconsistent screening and over-IS may be playing a role. The poor outcome of 72% of the BKVN cases is in part due to late diagnosis at a severe stage of disease. Late onset BKVN is an underrecognized cause of graft loss and dysfunction, and rigorous screening followed by tapering of IS on positive testing, should be emphasized beyond the first year post-transplantation.
Category: Kidney (does not include tumors)
Wednesday, March 2, 2011 1:00 PM
Poster Session VI # 271, Wednesday Afternoon