ABO-incompatible kidney transplantation: current practice and the decade ahead

Purpose of review With rapidly growing deceased donor kidney transplant waiting lists, solutions to the shortage of kidney donors need to come from many corners. This review focuses on the current results and upcoming medications that will allow broad expansion of ABO-incompatible transplantation as one facet to combat this issue. Recent findings Outcomes of ABO-incompatible kidney transplantation are comparable to standard living donor transplantation but carry a significant, early risk of antibody-mediated rejection. Reducing this early rejection risk will be critical for a broader adaption of incompatible transplants. Improvements in the measurement of isohemagglutinin antibodies with less variability, will reduce patient risk. The anti-CD20 antibody rituximab has replaced splenectomy at most centers with equivalent outcomes, eliminating the need for additional surgical intervention. Studies of complement inhibitors have proven effective in treating antibody-mediated rejection in animal models and human studies are currently ongoing. Studies in xenotransplantation show that blood group carbohydrate antigens can be effectively removed ex vivo prior to implantation. Ongoing studies of accomodation in animal models are finding protective changes in endothelial cells and the immune system that could become targets for pharmacologic manipulation. Summary Improvements that reduce risk of early rejection and its long-term sequelae will allow ABO-incompatible kidney transplantation to be adopted broadly along with paired kidney exchange programs, to address the donor organ shortage.