Overcoming immunological barriers to living donor kidney transplantation at Stanford University Medical Center

Aims: The outcome of living donor kidney transplantation (LDKT) is better than the outcome of deceased kidney transplantation, and the deceased donor pool has been slow to expand. Although recipients may have willing and healthy donors, immunological barriers can still prevent successful kidney transplantation. Therefore, we studied kidney transplant candidates at our institution with incompatible living donors to understand the barriers to LDKT and to develop strategies to overcome them. Methods: We identified candidates in our programme who have potential donors that have been rejected either because of ABO incompatibility or because of a positive cross-match. Age, blood type, panel reactive antibody (PRA), donor blood type, donor age and cross-match results were collected and analysed. Results: Currently, 790 patients at the Stanford University Medical Center are on the kidney transplant waiting list in the United States. Of the 355 patients on this list who are "active" and ready for kidney transplantation, 41 had 67 potential living donors that were incompatible. Twenty-seven donors were ABO incompatible, and 40 had a positive cross-match; 32% of the kidney transplant candidates had a class I PRA ≥ 80%, and 41% had a class I PRA<30%. Conclusions: A significant portion of patients on our kidney transplant waiting list have potential living donors that are incompatible because of immunological barriers. Based on our analysis, we have identified 2 strategies to increase the use of living donors: (1) Kidney paired donation transplantation (KPD); and (2) kidney transplant recipient desensitisation. The choice of strategy depends largely on the PRA of the recipients. Recipients who have a low PRA may benefit most from a paired organ exchange programme while those with a high PRA may benefit more from a desensitisation programme. We also believe that KPD programmes in the United States would benefit by combining their recipient-donor pools to optimise the number of successful organs exchanges.