Polyomavirus BK Viremia in Kidney Transplant Recipients After Desensitization With IVIG and Rituximab

Background Desensitization with intravenous immune globulin (IVIG) and rituximab improves transplantation rates. It is unclear if desensitization increases the risk of polyomavirus BK (BKV) viremia. Here, BKV viremia in HLA-sensitized patients after desensitization with IVIG and rituximab was analyzed. Methods Baseline characteristics and outcomes were compared in the desensitized group (N=187) and the non-desensitized group (N=284). Surveillance for BKV viremia was done at 1, 2, 3, 6, 9, and 12 months posttransplant. Univariable and multivariable analyses were performed. Results BKV viremia was observed in 20% of the desensitized and 10% of the non-desensitized (P<0.001) groups by 2 years posttransplant. The desensitized group had more lymphocyte depleting induction and more rejection. They also had a greater degree of viremia with more patients having a peak viral load greater than 10,000 copies per milliliter (P<0.001). However, there was no significant difference in BKV-associated nephropathy or graft loss in the two groups. There was an association of BKV viremia with desensitization and lymphocyte induction. Only desensitization remained a significant predictor in the multivariable model with an adjusted HR of 2.13 (95% CI 1.21-3.77, P=0.009). Conclusions Desensitization with IVIG and rituximab is associated with a higher incidence of BKV viremia with high viral copies and was the major predictor of BKV viremia in the multivariable model. More frequent surveillance for BKV viremia and an early, aggressive treatment strategy are essential for preventing high BKV viral loads in this patient population.