ABSTRACT

INTRODUCTION The dream of replacing a diseased human organ with one from a dead person is

ancient: legend states that Saints Cosmas and Damien in the fourth century A.D. miraculously transplanted a leg from a dead man. Such a creature would be a chimera, named after the “mingled monster” of Homer’s Iliad. The scientific study of the biology of transplanting tissue dates to the first years of this century, when Little and Tyzzer1 defined the Laws of Transplantation, paraphrased as: “isografts succeed; allografts are rejected.” The clinical practice of transplantation is gov­ erned by these laws. This chapter introduces the immunologic events in trans­ plantation, and in particular the molecular basis of these events, to be supplemented by reviews.214 Table 1.1 summarizes our approach, and Table 1.2 presents some useful terms. A recurrent theme is the “alio” relationship, which describes the relationship between two members of the same species who are not genetically identical. Thus we can describe alloantigens, allografts, and alloantibody.