BK nephropathy is an important preventable cause of graft loss, with the only universally accepted risk factor being overall burden of immunosuppression. In the absence of specific therapy, avoidance of graft loss is dependent on early detection of viral replication and appropriate reduction in immunosuppression. Identification of novel risk factors may permit more intense monitoring of at risk patients. Anecdotal observations suggested plasmapheresis might be a risk factor for BK viremia.

We reviewed outcomes of 805 patients undergoing renal transplantation at a single centre between January 2003 and December 2011, with specific attention to occurrence of BK viremia. Multivariate logistic regression was used to examine the influence of plasmapheresis, recipient age & gender, HLA matching, levels of immunosuppression and cellular and antibody mediated rejection on BK viremia.

While there was a trend to increased BK viremia following rejection on univariate analysis, this did not reach statistical significance. The only significant risk factor for BK viremia by univariate and multivariate analyses (Table 1) was exposure to plasmapheresis with an adjusted odds ratio of 2.07 (95% CI: 1.09 – 3.94, P < 0.05).

This large study identified plasmapheresis as a significant risk factor for BK viremia. More frequent monitoring of patients undergoing plasmapheresis may identify BK viremia earlier, enable appropriate reduction in immunosuppression and reduce the incidence of BK nephropathy.

« Back to 2015 American Transplant Congress