HIGH SURVIVAL RATES OF KIDNEY-TRANSPLANTS FROM SPOUSAL AND LIVING UNRELATED DONORS

Background. In the United States, increasing numbers of persons are do nating kidneys to their spouses, Despite greater histoincompatibility, the survival rates of these kidneys are higher than those of cadaveri c kidneys. We examined the factors influencing the high survival rates of spousal-donor kidneys. Methods. Kidney-transplant data from the Un ited Network for Organ Sharing Renal Transplant Registry were used to calculate graft-survival rates with Kaplan-Meier analysis. Results. Th e three-year survival rates were 85 percent for kidneys from 368 spous es, 81 percent for kidneys from 129 living unrelated donors who were n ot married to the recipients, 82 percent for kidneys from 3368 parents , and 70 percent for 43,341 cadaveric kidneys. The three-year survival rate for wife-to-husband grafts was 87 percent, which was the same as for husband-to-wife grafts if the wife had never been pregnant. If th e wife had previously been pregnant, the three-year graft-survival rat e was 76 percent (P = 0.40). The three-year graft-survival rate among recipients of spousal grafts who did not receive transfusions preopera tively was 81 percent, as compared with 90 percent for recipients who received 1 to 10 transfusions preoperatively (P = 0.008). The superior survival rate of grafts from unrelated donors could not be attributed to better HLA matching, white race, younger donor age, or shorter col d-ischemia times, but might be explained by damage due to shock before removal in 10 percent of the cadaveric kidneys. Conclusions. Spouses are an important source of living-donor kidney grafts because, despite poor HLA matching, the graft-survival rate is similar to that of pare ntal-donor kidneys. This high rate of survival is attributed to the fa ct that the kidneys were uniformly healthy.