The host response in experimental corneal xenotransplantation.

In addressing the worldwide shortage of human donor cornea for transplantation, animal cornea may be a substitute if mechanisms of xenogeneic (cross-species) rejection can be identified and controlled. Xenotransplantation of solid organs is followed by hyperacute rejection with minutes due to humoral graft rejection. In an experimental model corneal xenografts in rats survived for 2-3 days, depending on the phylogenetic disparity of the donor animal. Endothelial injury was the specific cause of graft failure, probably mediated by humoral rejection mechanisms. A later cell-mediated rejection response was seen. The potent humoral response is the most important feature differentiating xenograft from allograft rejection.