Outcome of ABO‐incompatible kidney transplantation using a modified desensitization protocol without plasmapheresis

Objectives Several controversies regarding desensitization strategies for successful ABO‐incompatible (ABOi) kidney transplantation still exist. This study aimed to investigate whether pretransplant anti‐A/B antibody removal is mandatory in an ABOi kidney transplant recipient with low baseline isoagglutinin titers. Methods We adopted a modified desensitization protocol with two doses of rituximab (RTX, 100 mg/body) without pretransplant antibody removal for ABOi kidney transplant recipients with a titer of ≤1:64 (group A; n = 35) and investigated the feasibility of this protocol by comparing it with the clinical outcomes of patients undergoing standard pretransplant plasmapheresis (group B; n = 21). Results There was no significant difference in the rate of antibody‐mediated rejection within the first month after transplantation between the two groups (11.4% in group A vs. 2% in group B, p = 0.6019). Moreover, no differences were observed in the short‐ and long‐term graft outcomes between the groups. However, two major critical acute antibody‐mediated events occurred in group A; one patient lost the graft due to hyperacute rejection, and the other patient developed thrombotic microangiopathy after surgery. Risk factors predicting these perioperative complications were not identified. Conclusions We conclude that not only B‐cell depletion using RTX but also pretransplant antibody removal is still recommended even for patients with low isoagglutinin titers. In addition, a new diagnostic tool is needed for accurate risk stratification.