EFFECTS OF CHANGES IN THE CRITERIA FOR NATIONALLY SHARED KIDNEY-TRANSPLANTS FOR HLA-MATCHED PATIENTS

Background. Nine years ago, a prospective trial began in all U.S. tran splant centers to determine whether the results of renal transplantati on would improve with the nationwide shipment of kidneys from cadaveri c donors to HLA-matched patients, Since then, the stringency of criter ia for HLA matching have been liberalized twice, from sharing only tho se kidneys that matched at all six HLA-A, -B, -DR antigens, to sharing phenotypically HLA-matched kidneys, and most recently to sharing zero HLA-mismatched kidneys, Methods. Data reported to the United Network for Organ Sharing Scientific Renal Transplant Registry from October 19 87 to December 1996 were analyzed to examine the transplant results of nationally shared HLA-matched kidneys and the effects of changes to t he HLA matching criteria on graft survival and the distribution of HLA -matched kidneys. Results. The overall 1-year graft survival rate of 5 102 HLA-matched transplants was 88% compared with 81% for 58,207 recip ients of kidneys with at least one HLA mismatch (P<0.001), HLA-matched kidneys had a projected 12-year graft half-life, 50% higher than the 8-year half-life of mismatched grafts (P<0.01), After the first change in the match criteria in August 1990, 1365 phenotypically matched kid neys with fewer than six HLA antigens identified had an 89% 1-year gra ft survival rate compared with 84% for 466 six antigen-matched kidneys transplanted before the change, After March 1995, 1067 zero HLA-misma tched kidneys that were not phenotypically identical nor six antigen m atched, had a 1-year graft survival rate of 88%, Craft survival has no t decreased as a result of these changes in the criteria for national sharing, despite an increase in the percentage of matched transplants from 2.5% during the six antigen-match era to 15.5% during the zero an tigen-mismatch era. Conclusions, Changes to the United Network for Org an Sharing policy for national sharing of HLA-matched kidneys have inc reased the number of patients, and especially minority patients, who c an benefit by receiving a well-matched graft without compromising the high graft survival rates provided by an HLA-matched kidney.