Effect of race on kidney transplants.

1. The 1-year graft survival rate for 3,525 Black recipients of first cadaver-donor transplants between 1985 and 1989 was 71%. For 13,866 Whites it was significantly higher at 78%, and 796 Asians had the highest 1-year graft survival rate at 83%. 2. When transplant centers were grouped according to the number of Black patients transplanted between 1985 and 1989, 1-year graft survival rates for Blacks ranged from 67% at centers that transplanted more than 100 Blacks to 74% at centers with 50-100 Blacks to 69% at centers with 1-50 Black transplants. The corresponding survival rates for Whites were 74%, 78%, and 78%, respectively (p less than 0.01 at each center group). 3. When the results were further stratified according to donor race and age, HLA-DR mismatches, and transfusions, a significant 6% difference remained between graft survival rates of Black and White recipients (p less than 0.01). 4. Similar stratified analyses for donor race yielded a significant 8% lower survival rate for Black donor kidneys compared to White donor kidneys (p less than 0.01). 5. More than 25% of Black recipients and donor kidneys were transplanted at 6 of the 204 centers reporting to the UCLA Transplant Registry, whereas 92 centers had transplanted no Black patients. 6. The main difference in survival between Whites and Blacks was among younger patients. There was a 13% difference for those younger than 30 (p less than 0.01), and only a 4% difference among patients older than 45 (p less than 0.05). 7. When HLA-DR antigens were matched, there was no difference in the survival rate between White and Black patients. This result was unaffected by the race of the donor, implying that racial HLA-DR variants may not be a major consideration in matching. 8. Black patients had poor long-term graft survival. The kidney half-life calculated after the first year for Black recipients was 3.7 years, and was 8.7 years for Whites (p less than 0.01). 9. There was a clear "center effect" component to racial differences in first cadaver kidney transplant outcomes related to the size of the Black recipient population. These center effects did not account for the overall difference between Black and White survival rates.