The UNOS Scientific Renal Transplant Registry--ten years of kidney transplants.

1. The number of kidney transplants reported to the UNOS Scientific Renal Transplant Registry (excluding multiorgan transplants) increased from 8,831 in 1988 to 10,204 in 1996, mainly due to increased donation by living donors (1,812-3,149 during the same period). 2. Overall projected 10-year primary graft survival rates were 73% for 3,515 recipients of HLA-identical sibling grafts, 55% for 16,160 recipients of other living donor transplants or 3,940 HLA-matched cadaveric grafts and 39% for 50,900 recipients of HLA-mismatched cadaver donor kidneys. 3. One-year first cadaver graft survival rates improved from 77% in 1988 to 87% in 1997 and graft half-lives improved from 7.6 years for 1988 transplants to 11.6 years for 1994 transplants. 4. Improving graft survival rates were associated with a modest 2% increase in one-year patient survival and a projected 13% increase at 10 years. Better patient survival may contribute to rising long-term graft survival rates. 5. Immunosuppression has also played an important role as the incidence of rejection episodes within the first 6 months decreased from 52% in 1988 to 24% in 1996 and immunological graft failures declined in 1995 and 1996 accounting for less than 30% of first year graft losses. The majority of first year graft losses were due to patient deaths for the first time in 1995. 6. A major change in maintenance immunosuppression occurred in 1996 when about 60% of first cadaver transplant recipients received Neoral, MMF and prednisone (NMP) at the time of hospital discharge. Preliminary results show a 90% one-year graft survival rate with NMP compared with 87% for CsA- and FK-based immunosuppression. Improved long-term graft survival that had been previously noted in patients treated with FK506 was not apparent in the 1994-96 cohort analyzed. The use of induction with OKT3 or ALG reduced rejection episodes during the initial transplant hospitalization but did not affect one-year or long-term graft survival. 7. There has been a significant improvement in immunological high-risk patients. The results of second transplants trailed those of primary grafts by only 3% in the 1994-96 period compared with a 6% difference in 1988-90 and recently retransplanted patients who were not broadly sensitized had the same graft survival rate as unsensitized first transplant recipients. Recipients of poorly HLA-matched kidneys also had significantly improved survival rates during 1994-96. The 3-year survival difference between recipients of kidneys with only one or 2 HLA mismatches and those with 5-6 mismatches was 4% compared with 8% for comparably matched recipients transplanted in 1988-90. 8. The 3-year graft survival rate for Black recipients was 57% in 1988-90 and 67% in 1994-96. The gap between Blacks and Whites narrowed from a 9% 2-year survival rate difference in the early cohort to 5% in the more recent transplants. Asians transplanted in 1994-96 had a superior graft survival rate of 90% at one year with an 18-year half-life. 9. Despite a substantial increase in the number of living donor transplants performed in recent years, graft survival rates were still superior to all but the best HLA-matched cadaver transplants. Most of the additional living donor activity has involved HLA-mismatched pairs with a 3-fold increase in the number of completely HLA-mismatched transplants (513 in 1988-90 vs 1,583 in 1994-96). The one-year graft survival rates were 96%, 93% and 92% for HLA-identical, one- and 2-HLA haplotype disparate transplants, respectively.