Purpose: To evaluate long-term follow-up of high-risk corneal transplants allocated after matching for broad HLA-A and HLA-B antigens and to establish whether matching for HLA-A and -B antigen "splits" would result in a reduced risk of immunologic graft failure.
Methods: A total of 303 high risk corneal transplants was included. Class I antigen-matched donor corneas were obtained using broad HLA-A and -B antigen data and accepting 0 or 1 mismatch at each locus. Analysis of HLA antigens was performed also on the split typing level. The influence on immunologic graft failure for an increasing number of matched class I antigens based on split typing was analyzed with Kaplan-Meier statistics and Cox regression. Graft survival and indication for transplantation were investigated.
Results: Rejection was the cause of 34% of all graft failures. A significantly higher immune failure free graft survival was found in a group with 0 or 1 HLA-A and -B mismatch based on split typing (log-rank test, P = 0.002). A beneficial effect of matching for split antigens was shown with multivariate analysis (odds ratio, 0.41).
Conclusions: One third of graft failures in our high-risk population was caused by irreversible graft rejection. Allocation of donor corneas based on a 0 or 1 split antigen mismatch at both HLA-A and -B loci could contribute to a higher immune failure free graft survival and could result in a higher overall graft survival.