[Kidney transplantation from an ABO-incompatible living donor]

Living donor kidney transplantation is the preferred therapeutic option for patients with end stage renal disease because it provides a superior immunological compatibility, it lessens the preservation-mediated graft injury and it shortens waiting time on dialysis. Unfortunately, about 30-35% of potential living kidney donors are rejected because of incompatible immunological barriers such as ABO-incompatibility or a positive crossmatch. The newest desensitization protocols based on both therapeutic apheresis and perioperative immunosuppressive drugs allowed to overcome antibodies barriers. The aim of those protocols is to wash-out and suppress as much anti-A or anti-B antibodies as possible and to prevent the rebound phenomena after transplantation. Standard plasmapheresis, double-filtration plasmapheresis and selective immunoadsorption are among the most common apheretic modalities applied in ABO-incompatible transplantation. Furthermore, selective immunoadsorption appears to be much safer and to have markedly increased efficacy comparing with plasmapheresis being able to eliminate almost exclusively blood-group antibodies avoiding plasma and coagulation abnormalities. According to literature, long-term patient and graft survival rates are similar to those achieved by ABO-compatible kidney transplants. The comparable outcome seems related to more effective desensitization protocols as well as the protective immune mechanisms of "accommodation". We have been using selective immunoadsorption in the two ABO-incompatible kidney transplants performed in our institution. No acute rejection was experienced at 6 and 26 month follow-up and both grafts are functioning well. Despite the ABO-incompatible kidney transplant widespread use, the best desensitization protocol, the upper baseline and perioperative isoagglutinin titer limit and the most accurate isoagglutinin measurement assay are still to define.