BK Virus Nephropathy and Risk of Allograft Function and Survival

BK virus-associated nephropathy (BKVAN) is associated with allograft dysfunction and graft failure in kidney transplant recipients. Reduction of immunosuppression is the gold standard of treatment for BKVAN, possibly increasing the risk for acute rejection.

Researchers in South Korea, led by Ji Won Min, MD, utilized data from the Korean Organ Transplantation Registry, a nationwide organ transplantation database, to compare graft function and allograft survival in patients with BKVAN with or without biopsy-proven acute rejection (BPAR). Results of the analysis were reported during a virtual poster session at the 28th International Congress of the Transplantation Society in a poster titled Differential Impact of Allograft Rejection on Kidney Transplant Patients with BKV Infection.

Of the 5403 kidney transplant recipients who underwent transplantation between 2014 and June 2019, 97 were diagnosed with BKVAN. Of those, 27% (n=26) developed BPAR within 5 months of the diagnosis of BKVAN; 71 patients did not develop BPAR. At baseline, both groups (with and without BPAR) had similar characteristics, immunosuppression treatment, and treatment methods for BKVAN.

In the BPAR group, there was a significant decrease in allograft function compared with the group without BPAR at both the 1 year and 2 year follow-up period (BPAR creatinine [Cr] 2.5 vs no BPAR Cr, 1.9; P=.044 and BPAR Cr 3.8 vs no BPAR Cr 2.2; P=.015, respectively). Allograft survival rates were lower in the BPAR group than in the no-BPAR group; however the difference did not reach statistical significance (P=.474).

In multivariate Cox regression analysis, discontinuation of mycophenolate mofetil (MMF) was seen as a significant risk factor for rejection in patients with BKVAN (hazard ratio, 4.000; 95% confidence interval, 1.014-15.775; P=.048).

In conclusion, the researchers said, “Acute rejection with BKVAN is associated with poorer allograft function and survival. Also, discontinuation of MMF as treatment for BKVAN increases risk for acute rejection.”

Source: Min JW, Jun KW, Park JB, et al. Differential impact of allograft rejection on kidney transplant patients with BVK infection. Abstract of a poster presented at the virtual 28th International Congress of the Transplantation Society (Abstract P-11.55), September 13-16, 2020.