Transplantation of a whole ear allograft by immunological induction of donor-specific tolerance by bone marrow transplantation: an experimental study in rabbits.

Previous studies in our laboratory have shown that giving bone marrow cells through the portal vein or intraosseous route is likely to be beneficial to tolerance of induction of allografts in rabbits. Using this model, we tested whether a less severe regimen for conditioning of the host can prevent rejection of allografts. Rabbits were given a single intraosseous injection of donor bone marrow cells and total body irradiation (7 Gy) and transplantation of skin and ear allografts. Mean skin allograft survival for this treatment was 88 days, which was similar to the results of our earlier study. A donor ear was accepted for more than a year with no signs of rejection. These results suggest that a single intraosseous injection of donor bone marrow cells is sufficient for induction of donor-specific tolerance in rabbits and that immunosuppressive agents may not be needed.