Recipient sex did not play a significant role in transplant outcome. 2. Donor sex emerged as a surprisingly major factor in recent transplants. Cyclosporine did not increase graft survival of female donor kidneys from donors between the ages of 31 and 50 above survival rates achieved by conventional immunosuppression. Male kidneys had a 7% higher one-year survival rate than female kidneys in first cadaver transplants and a 13% higher one-year survival rate in regraft recipients treated with cyclosporine. 3. Female donor kidneys had poorer early function rates in cyclosporine-treated patients. The first day nonfunction rate was 27% in first cadaver recipients of female donor kidneys and 19% for male donor kidneys. Among recipients whose kidneys did not function in the early posttransplant period, recipients of female donor grafts had higher average serum creatinine levels than recipients of male donor grafts. 4. The poorer survival and early function rates of female cadaver donor kidneys were also affected by the age of the donor in first transplant recipients. Kidneys from females less than 30 years old survived as well as male donor kidneys, suggesting that the effect was not strictly sex-associated. 5. Matching for HLA-A,B antigens abrogated the effect of donor sex. Graft survival was the same for both male and female kidneys when no HLA-A,B antigens were mismatched between the donor and recipient in first cadaver, cadaver regraft, and living-related donor transplants. Mismatches at HLA-A,B reduced survival of female donor grafts in patients who were retransplanted by as much as 25% at one year, while male donor grafts were much less affected. 6. Black recipients had significantly lower graft survival rates than white recipients of first cadaver donor transplants. Although cyclosporine improved graft survival in blacks, there remained a 10% discrepancy between the survival of transplants in black recipients and in white recipients. 7. Although the number of transplants was small, there was no apparent race effect in blacks who were retransplanted with a cadaver donor kidney or who received a transplant from a living related donor when cyclosporine was used. 8. The poor graft survival of black donor kidneys transplanted to white recipients was due in part to very poor HLA matching. 9. The black donor kidney showed a striking similarity to the older female donor kidney in recipients treated with cyclosporine. There may be an association between cyclosporine nephrotoxicity or rejection and kidneys from hypertensive donors. 10. There were no differences in graft survival between recipients of the various blood types in recent transplants.(ABSTRACT TRUNCATED AT 400 WORDS)
