Histocompatibility Y antigen compatibility and allograft rejection in corneal transplantation

To assess the effects of histocompatibility Y (H-Y) antigen matching on the rate of corneal allograft rejection after penetrating keratoplasty (PKP).

We retrospectively investigated the graft survival rate and rejection-free graft survival rate after PKP in 396 eyes. The compatible combinations of H-Y antigen included male donors and male recipients (n = 135), female donors and male recipients (n = 107), and female donors and female recipients (n = 60). Incompatible combination was from male donors and female recipients (n = 94). The eyes were classified into two groups--high-risk (168 eyes) and low-risk (228 eyes)--depending on the degree of vascularisation in the recipient corneas or a history of previous allograft rejection. Data were analysed using the Kaplan-Meier life table method, the log-rank test and the Cox proportional hazards model.

In both the high-risk and low-risk groups, the graft survival and rejection-free graft survival rates were not affected by the H-Y compatibility. The graft survival (p < 0.001) and rejection-free graft survival (p < 0.001) rates were higher in the low-risk group than in the high-risk group. High-risk PKP was associated with greater risk of graft failure (risk ratio, 2.33) and rejection (risk ratio, 2.05) than low-risk PKP.

H-Y antigen matching does not influence the rate of allograft rejection after PKP.