Post-Transplantation Immunoadsorption Can Be Withheld in ABO-Incompatible Kidney Transplant Recipients

After ABO-incompatible kidney transplantation, postoperative plasma exchange (PE) or immunoadsorption (IA) is performed per protocol or depending on postoperative A/B-titers to prevent acute rejection. However, the need for postoperative PE or IA is not known. Since 2006, 30 consecutive patients received three standard postoperative IAs. Starting from 2009, the last 46 patients received only preoperative IA. Preoperative desensitization consisted of rituximab, tacrolimus, mycophenolate mofetil, prednisone and intravenous immunoglobulins. Antigen-specific IA was performed pre-operatively with the Glycosorb device. Biopsy-proven acute rejections either antibody-mediated (AMR) or mixed cellular and antibody-mediated (MAR) within 3 months were recorded. The postoperative titer in patients with postoperative IA did not exceed 1:16 (IgG 1:4 [<2-16] median and range). The postoperative IgG titer was not significantly different after abandoning postoperative IA, although three patients had titers of 1:32 and one patient even 1:128. Rejections tended to be more frequent in the group with postoperative IA: 6 AMR and 3 MAR were recorded in 30 patients, vs. 4 AMR and 1 MAR in the 46 patients without postoperative IA (30 vs. 11%, P = 0.067). Baseline characteristics differed however: in the group with postoperative IA the vast majority had blood group O (87 vs. 52%, P = 0.003). Also, the IgG titer on the day of transplantation was higher (1:4 [<2-16] vs. 1:2 [<2-32], P = 0.007). All 14 patients with AMR and MAR rejections had postoperative IgG titers ≤1:16. Postoperative removal of A/B-antibodies can be safely removed from the ABOi transplantation protocol using strict preoperative criteria for antibody lowering.