RENAL TRANSPLANTATION: Edited by Rainer OberbauerABO-incompatible kidney transplantationFehr, Thomasa; Stussi, GeorgbAuthor Information aDivision of Nephrology, Zurich Transplant Center and University Hospital, Zurich bDivision of Hematology, Oncology Institute of Southern Switzerland, Bellinzona, Switzerland Correspondence to Professor Thomas Fehr, MD, Division of Nephrology, University Hospital, Rämistrasse 100, CH-8091 Zurich, Switzerland. Tel: +41 44 255 3384; fax: +41 44 255 4593; e-mail: email@example.com Current Opinion in Organ Transplantation: August 2012 - Volume 17 - Issue 4 - p 376-385 doi: 10.1097/MOT.0b013e328355f013 Buy Metrics Abstract Purpose of review A dramatic shortage of available organs around the world encouraged attempts to cross previously forbidden immunological boundaries in kidney transplantation. This review focuses on the recent results of ABO-incompatible kidney transplantation. Recent findings The outcome of ABO-incompatible kidney transplantation in terms of patient and graft survival is comparable to ABO-compatible transplantation for adult and pediatric recipients. Splenectomy has been replaced by the B-cell-depleting agent rituximab to avoid isoagglutinin titer rebound, prevent antibody-mediated rejection, and improve graft survival. However, the risk for infections may be increased and warrants caution. Corticosteroids remain a necessary component of any ABO-incompatible protocol; early as well as late steroid withdrawal may bear an enhanced risk for acute rejection and should only be performed with careful follow-up including protocol biopsies. The few studies that have long-term outcomes using protocol biopsies have characterized a state of accommodation by up-regulation of complement inhibitors, down-regulation of A/B antigens, and establishment of endothelial chimerism over time. Summary The experience accumulated around the world indicates that ABO-incompatible kidney transplantation is well tolerated and effective in adults and in children, and it represents an important step forward in expanding the living donor pool. Further understanding of ABO-incompatible graft accommodation may have broader implication also for human leukocyte antigen-sensitized allograft recipients. © 2012 Lippincott Williams & Wilkins, Inc.