Long-term graft survival rate of zero-mismatch kidney transplants for HLA-DRB1.

The study of a two-locus association between HLA-B and -DRB 1 revealed a significant 43 linkage disequilibrium. Donor-recipient HLA-DRB1 was determined by these 43 linkages. Zero-mismatch for HLA-DRB1 had a significant effect on the graft survival rate in living related and cadaver transplants. The 5-year graft survival rate was 94% in the zero-mismatch group for HLA-DRB1, 96% for related transplants, 92% for cadaver cases, and 94% in HLA identical siblings. A statistically significant difference was found between the zero-mismatch group for HLA-DRB1 and mismatch groups for HLA-DRB1 or HLA-DR (P < 0.01). The zero-mismatch group for HLA-DRB1 had mismatches for HLA-A and/or HLA-B in 46 of 70 cases (66%). No significant differences in the rejection rate was observed between zero-mismatch and mismatch cases for HLA-A and/or -B in the zero-mismatch group for HLA-DRB1. In the second step, genotyping was conducted in 118 cases. The 5-year graft survival rate was 93% in the zero-mismatch group for HLA-DRB1 and 86% in mismatch group (not a significant difference). We concluded that zero-mismatch transplant for HLA-DRB1 had a better long-term graft survival rate regardless of HLA class I.