During the infancy days of cardiac transplantation, nonhuman primate hearts were transplanted into humans to save lives. This type of transplantation is best described by which one of the following?: (A) Allograft: transplant from one species to the same species, (B) Autograft: transplant from one region of a person to another region, (C) Isograft: transplant from one person to a genetically identical person, (D) Xenograft: transplant from one species to another species
Answer is D. Transplantation from one region of a person to another region of that same person is an autograft and has the best chance of succeeding. When a transplant is done between monozygotic twins, it is an isograft and has a complete MHC compatibility and a good chance of success. Allografts are between members of the same species, and xenografts are between members of different species. Both of these transplants have a high rate of rejection unless immunosuppression accompanies the transplant.