FIVE–YEAR REPORT OF A CREG ALLOCATION VARIANCE

6.1
TITLE: FIVE–YEAR REPORT OF A CREG ALLOCATION VARIANCE

Steven K Takemoto,¹ Elaine F Reed,¹ J. Michael Cecka.¹

¹Immunogenetics Center, UCLA, Los Angeles, CA

In 1995, a variance for allocation of cadaveric renal allografts based on a set of 10 HLA class I and 7 class II Cross Reactive Groups (CREGs) was adopted in a large local region with approximately 3600 candidates waiting for a transplant. Projections indicated CREG matched recipients would be identified for 20% of transplant recipients and 695 cases would be needed to achieve significance with the projected decreased hazard of 40%.

Through the end of 2000, 2026 transplants were performed with 14% of recipients having 0 HLA–A,B,DR mismatches (MM), 10% 0 CREG MM and 76% with CREG MM. Three–year survival for the respective cohorts were 84% (77–89, 95% C.I), 89% (82–93), and 82% (79–84, P = 0.5). Fewer rejections were reported during the 1st post–transplant year for the better match grades (10, 10, 17%, P = 0.004). Distribution by donor race was: 61% White, 8% Black, 24% Hispanic, and 6% Asian. Donors and recipients had different races for 42% of the 0 A,B,DR, 53% 0 CREG and 64% (P < 0.001) of the CREG MM transplants. This distribution if inter–racial allocation was much higher than a recently reported in prospective multi–center trial (1).

Allocation based on CREG mismatches resulted in fewer rejections and outcome similar to zero HLA mismatched transplants. These results support adoption of a CREG allocation variance in regions wishing to increase the rate of inter–racial allocation of cadaveric renal allografts.

1. Takemoto et al. Submitted to N Engl J Med.