Histocompatibility (HLA) antigens and keratoplasty

Area of Science:

• Ophthalmology
• Immunology
• Transplantation

Background:

• High-risk keratoplasty involves patients with pre-existing sensitization to human leukocyte antigens (HLA).
• Prior sensitization occurs through pregnancy, blood transfusions, or previous transplants, increasing rejection risk.
• Densely vascularized corneas present a significant challenge in corneal transplantation.

Purpose of the Study:

• To evaluate the impact of donor-recipient HLA matching and crossmatch status on keratoplasty outcomes in high-risk patients.
• To determine the significance of pre-transplant sensitization in graft success.
• To identify optimal donor selection criteria for high-risk corneal grafts.

Main Methods:

• Retrospective analysis of 103 high-risk keratoplasty cases.
• Donor selection based on negative crossmatch to avoid pre-sensitizing HLA antigens.
• Evaluation of graft failure rates due to rejection.
• Analysis of correlation between shared HLA antigens and graft outcome.

Main Results:

• Overall graft failure rate from rejection was 15% in 84 analyzed cases.
• No consistent correlation found between the number of shared HLA antigens and graft outcome in high-risk cases.
• Negative crossmatch was identified as a critical factor in donor selection.

Conclusions:

• A negative crossmatch is vital for successful donor selection in high-risk keratoplasty.
• Minimizing exposure to known donor-specific HLA antigens is key to preventing rejection.
• Current HLA matching strategies may not be as critical as crossmatch status in these challenging cases.