Effectiveness of an organ-sharing program in providing zero HLA-A,B,DR mismatched kidneys for transplantation in Taiwan

Purpose: This study evaluated the effects of organ sharing on the allocatio n of kidneys from cadaveric donors to uremic patients from National Cheng K ung University Hospital (CKUH) and National Taiwan University Hospital (NTU H) who were waiting for kidney transplantation. Methods: Standard complement-dependent microcytotoxicity assays were used. Human leukocyte antigen (HLA)-A,B,C typing was performed on nylon-wool-enri ched T lymphocytes. HLA-DR typing was performed on either nylon-wool-separa ted B cells or Dynabeads. Isolation of class II-positive cells was performe d with commercial typing trays. Results: Organs were allocated from a total of 88 cadaveric donors to 320 p atients treated at CKUH and 179 patients treated at NTUH. Cadaveric kidneys could be allocated with an A,B,DR mismatch to 6.9% of CKUH patients and to 4.7% of NTUH patients. When CKUH and NTUH patients were pooled, the total number of kidneys that could be allocated with 0-A,B,DR mismatch increased to 13.3% (p < 0.004). However, when allocation was assessed using 10,000 po tential bone marrow donors instead of the 88 cadaveric donors, kidneys coul d have been allocated with 0-A,B,DR mismatch to 12% (p = 0.64) of patients. No significant benefit was found when allocation estimates from the 10,000 potential bone marrow donors were compared with those for the 88 cadaveric donors. Use of epitope matching resulted in a Oa,B cross-reactive epitope group, and a 0-DR mismatch allocation rate of 36.4% in CKUH patients and 31 .8% in NTUH patients. This rate increased to 54.6% (p < 0.001) when the pat ients from these hospitals were pooled. Conclusion: The results of this study demonstrate that the pooling of patie nts among regional transplant centers in Taiwan can significantly enhance t he benefits of an organ donation program through better HLA matching.