Acceptable Donor-Specific Antibody Levels Before and After Desensitization Therapy in Living Donor Kidney Transplantation.

Background: Plasmapheresis (PP) is commonly used for desensitization in highly sensitized patients with donor-specific antibodies (DSA) in living donor kidney transplantation. We analyzed the impact of DSA levels before and after desensitization on renal allograft outcome. Methods: Twenty-three patients who underwent desensitization with PP, intravenous immunoglobulin (WIG), and rituximab before kidney transplantation in Seoul National University Hospital from August 2006 to August 2016 were enrolled. The association of median fluorescent intensity (MFI) value of DSA with graft outcome was analyzed. Results: The frequency of positive HLA class II DSA after desensitization was lower in patients without antibody-mediated rejection (AMR) compared to those with AMR (p = 0.006). The cutoff value of MFI sum of HLA class II DSA after desensitization for predicting AMR was 2,122 with 63% sensitivity and 94% specificity. The frequency of moderate HLA class II DSA (MFI 5,000 - 10,000) after desensitization was significantly higher in patients with graft loss compared to those without graft loss (p = 0.02). Conclusions: Weak HLA class II DSA after desensitization including PP, WIG, and rituximab was related to AMR and moderate levels of HLA class II DSA after desensitization was related to graft loss in living donor kidney transplantation.