A study of patients undergoing corneal transplants indicates that subtle differences between men and women may lead to poorer outcomes for a woman who has received a cornea from a male donor. The findings, which are published in the American Journal of Transplantation, suggest that gender matching may be beneficial to potentially reduce the risk of failure and rejection in patients undergoing corneal transplantation.
In this latest study, a team led by Stephen Kaye, MD of The University of Liverpool and The Royal Liverpool University Hospital and Cathy Hopkinson of NHS Blood and Transplant investigated whether donor and recipient gender incompatibility influences corneal transplant rejection and failure up to five years post-transplant.
More than 18,100 patients were identified in the UK who had undergone a first corneal transplant. While over 80 percent of all patients included still had a functioning graft at 5 years, a higher proportion of male to female transplants failed or rejected during this time, when compared with gender matched transplants. For every 1000 people transplanted with a gender matched cornea, on average 180 will fail, compared with 220 for male to female mismatched grafts.
The effect of gender matching was especially evident in patients with Fuchs endothelial dystrophy, a condition that affects a thin layer of cells that line the back of the cornea. Of 4,046 patients with Fuchs endothelial dystrophy, 18 percent of male to female mismatched grafts failed compared with 12 percent of female to female transplants. After adjusting for various factors, female to female transplants were 40 percent less likely to fail and 30 percent less likely to reject compared with male to female mismatches.
"These findings are most likely a result of H-Y antigen incompatibility associated with the male Y chromosome," explained Professor Kaye. "Females do not have a Y chromosome so there is no H-Y incompatibility from female donors to male patients. This effect, however, is not reciprocated when the roles are reversed, that is, when male donors are transplanted to female recipients."
He noted, however, that further studies will be necessary to confirm the findings and to justify the potential allocation of corneas from male donors to male recipients and those from female donors to either female or male recipients.
"If confirmed, this would be relatively straightforward to put into place without delay in donor tissue allocation to patients or any significant added cost," said Professor Kaye. "The long-term impact this could have on patient care may be substantial."