Porcine Corneal Xenotransplantation Using a Human Graft

Abstract

Purpose: : To evaluate xenotransplantation of a human corneal graft in a porcine recipient.

Methods: : A single young pig underwent penetrating keratoplasty using a full-thickness corneal graft of human origin (C). No immunosuppressant agents were administered during the study. The grafted eye was clinically slit lamp examined at intervals in the observation period of 15 days. Serum and peripheral mononuclear cells were collected for analysis of antibodies against a human T cell line, and for IL-4 and IFN-γ producing cells respectively. The grafted eye was processed for histopathological analysis after enucleation. For comparison two other pigs underwent similar surgical procedures using an autogeneic (A) or an allogeneic (B) corneal graft respectively.

Results: : The human graft survived for 15 days in the pig. The pig possessed preformed anti-human antibodies. However, grafting did not increase the antibody titers nor induce isotype switching. Grafting increased the production of both IFN-γ and IL-4 from porcine peripheral blood mononuclear cells. Histological examination revealed a high density of eosinophils in the transplant.

Conclusions: : No hyperacute nor delayed acute rejection, but a delayed rejection was observed of the human corneal xenograft in the pig. This indicates that adjuvant immune suppressive intervention is needed in order to secure survival of the xenograft.

Keywords: transplantation • cornea: basic science • inflammation