Kidney transplantation in highly sensitized patients: reappraisal of etiology, evaluation, and management protocols

Transplant recipient sensitization to major histocompatibility complex (MHC) antigens is a major problem in clinical organ transplantation in terms of both magnitude and implication. Highly sensitized patients (HSPs) waiting for renal transplantation constitute a high-risk group with difficult management problems. In this review the factors involved in sensitization, detection of sensitization in the pretransplant period, various strategies tried in its prevention, and the current therapeutic approach to management of HSPs are discussed. Although prevention of sensitization is ideal, in practice a certain percentage of transplant recipients continue to exhibit hypersensitization despite all measures. Methods to remove preformed antibodies are effective but are expensive and not freely available. Aggressive immunosuppression based on cyclosporine (CsA) induction protocols constitute the mainstay in the management of HSPs. The availability of newer, potent, and more specific immunosuppressive agents, particularly those suppressing antibody synthesis, has opened a new avenue for more specific immunosuppression and better graft and patient survival following transplantation. Their clinical utility in improving patient and graft survival in HSPs needs to be evaluated.