Cellular immunity to xenogeneic corneal grafts in rabbits

We wished to determine whether a small orthotopic corneal xenograft could sensitize a host systemically. Ten rabbits were grafted with interlamellar bovine cornea and pre- and postoperative blood samples tested by the H3 thymidine incorporation test (micro-method). The leucocyte migration inhibition test was applied in 3 animals. A skin test was performed on all rabbits in the 4th postoperative week. The challenging antigen used was a homogenate of pooled bovine corneas. Clinically and histologically each rabbit showed a characteristic corneal graft reaction. Where performed, leucocyte migration inhibition tests were positive after grafting as were all skin tests. The H3 thymidine incorporation test did not detect specific systemic sensitization although increased numbers of DNA synthesizing cells were present in the blood during the graft reaction. We conclude that a bovine corneal xenograft can induce systemic sensitization in a rabbit host.