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Background: Improved HLA matching can allow for renal transplantation in sensitized patients. United Network for Organ Sharing (UNOS) is currently considering removing the points awarded for HLA matching., Method: Twenty-six transplant centers shared kidneys, according to the algorithm: A, UNOS mandatory 0-mismatch (MM) share; B, UNOS mandatory 0-mm payback; C, 0 - B,Dr-MM; PRA> or = 40%; ROP tray negative; D, 0-B,Dr-MM; panel reactive antibodies (PRA) <40%; E, 0-B,Dr payback; F, local use., Results: A total of 354 patients received transplants through the program and were compared with 6492 control patients. There was a significantly greater primary nonfunction rate in sensitized patients in spite of similar length cold ischemia time. Blacks were not significantly disadvantaged by the HLA matching requirements of the program. White recipients were favored by the matching program to the detriment of race group "other." Women were more frequently found in the sensitized groups but were not favored by sharing. Retransplant patients and patients with current PRA > or = 40% were favored by the sharing program. Sharing for HLA match does not improve graft survival at 1, 2, 3 years., Conclusions: (1). Elimination of suboptimal HLA matching by UNOS will probably not adversely affect 1-, 2-, and 3-year graft survival; (2). Removing the consideration for HLA matching will result in fewer transplant opportunities for highly sensitized patients such as retransplants and currently sensitized patients.

In summary, the HGM program is a voluntary, multicenter, prospective study of the SEOPF that is open to all transplant centers. The program extends mandatory sharing beyond the UNOS zero-antigen mismatch obligation, and uses preliminary crossmatching via ROP trays to try to facilitate transplantation of the highly sensitized patient. The program encompasses less than 7% of the cadaver kidney transplant activity of the participating centers, so it does not impact the majority of recipients. After 49 months of operation, it has significantly improved access to transplantation for blood group O patients, patients awaiting re-grafts, and those who are highly sensitized (PRA > or = 40%). Additionally, 92% of the HGM recipients have received an allograft with 2 or less antigens mismatched. Enrollment will continue until there is sufficient power to test the null hypothesis of equality of HGM and non-HGM transplants.

Background: Studies of kidneys shared through the South-Eastern Organ Procurement Foundation (SEOPF) have shown that regional organ procurement (ROP) trays can predict negative crossmatch in highly sensitized patients when the HLA match is of a high grade. In an attempt to offer more well-matched kidneys to highly sensitized patients, SEOPF organized the High Grade Match (HGM) Program., Methods: This United Network for Organ Sharing (UNOS)-approved allocation variance requires mandatory sharing of all kidneys by participating centers after UNOS mandatory sharing requirements have been met. The HGM levels of sharing are: (1) 0 A,B mismatch (MM); panel-reactive antibody (PRA) > or = 40%; negative ROP crossmatch; (2) 0 B,DR MM with > or = 40% PRA; negative ROP crossmatch; (3) 0 B,DR MM with PRA < 40%. Non-HGM cadaveric transplants at the same participating centers--locally or distally procured--serve as the control group., Results: During the first 18 months of this program, the 23 participating centers shared 124 kidneys of the 1592 that were available. Well-matched kidneys (two mismatches or less) accounted for 91.1% in the HGM group, but only 19% of the controls (P<0.0001). Highly sensitized patients (PRA > or = 40%) represented 13.8% of the HGM group, but only 3.3% of the non-HGM group (P<.0001). With HGM kidneys, there was a shift in recipient demographics. Patients with blood group O, female patients, older patients, and retransplanted patients all accounted for significantly larger percentages of the HGM group compared with the non-HGM control group. The racial composition of the recipients of high-grade matches was, however, no different than that of the control recipients at the same centers., Conclusion: The HGM Program resulted in longer ischemia times, but graft survival was not affected. The 1-year actuarial graft survival rate (Kaplan-Meier) for HGM kidneys was not different from the control cadaveric graft survival rate. By sharing kidneys based on improved HLA matches with consideration for high PRA, the HGM Program offered more transplant opportunities to women, blood group O recipients, retransplants, and older patients.