The purpose of this case control study was to identify risk factors for transplant failure due to BK Nephropathy (BK).

Using SRTR data from 1987-2011, we identified n= 756 kidney transplant failures due to BK. We excluded n= 217 living donor transplants, and n =79 deceased donor transplants where either no mate kidney was transplanted, or a single recipient received two organs.

The remaining 460 BK transplant failures (cases) were linked to their mate kidney (controls). In only 2/460 pairs, both kidneys failed due to BK and were excluded. We further excluded 39 pairs in which the control kidney had evidence of treatment for BK infection. The final study population included n = 419 BK pairs. After a mean follow up of 5.35± 3.40 years, graft survival in the controls was 67 %.

Univariate comparisons were performed using the Mantel- Haenszel test for frequencies on the following variables: age, sex, race, cause of ESRD, blood type, CMV match, HLA mismatch, PRA, cold ischemic time, acute rejection in the first year after KTx (AR), maintenance steroids, calcineurin inhibitor, and induction therapy. The independent association of factors with graft failure due to BK was determined using conditional multivariate logistic regression analysis including all variables associated with the outcome of interest in univariate analyses (p<0.10).

We conclude that donor factors play a minor role in transplant failure due to BK because in only 2/460 pairs did both kidneys fail due to BK. Further in only 39/460 pairs was there evidence of BK infection in the control kidney. This unique paired kidney analysis also confirms the strong association of male gender, acute rejection in the first post transplant year, and treatment with tacrolimus as opposed to cyclosporine with transplant failure due to BK.

« Back to 2013 American Transplant Congress