Immunosuppression in sensitized recipients.

Abstract

Due to a substantial lack of kidney donor organs and an increasing number of sensitized recipients, a growing number of kidney transplantations has to be performed across human leukocyte antigen (HLA) and ABO barriers. These transplantations carry an inherent risk of antibody-mediated rejection (AMR) with subsequently impaired graft and patient survival. This review focuses on new developments in desensitization strategies and dedicated programs for sensitized allograft recipients. Whereas ABO-incompatible kidney transplantation using rituximab-based desensitization achieves long-term survival rates comparable with ABO-compatible kidney transplantation, HLA-incompatible living kidney transplantation shows no definite survival advantage as compared with staying on the waiting list for an HLA-compatible organ. To overcome HLA-incompatibilities dedicated programs for highly sensitized recipients (such as the Eurotransplant Acceptable Mismatch program) have been established. For optimal graft outcome, these programs should be based on proven acceptable mismatches and not just on avoiding unacceptable antigens. Novel desensitizing agents (e.g. complement inhibitors) that specifically inhibit the molecular pathways of AMR have shown promising results in HLA-incompatible kidney transplantation in smaller studies. Despite ever more challenging conditions, kidney transplantation in highly sensitized patients can be achieved with the use of dedicated programs, well established desensitizing agents and new drugs that specifically inhibit the molecular processes of AMR.