Genetic and Antigenetic Aspects of Human Histocompatibility Systems

Publisher Summary This chapter discusses the genetic and antigenetic aspects of human histocompatibility systems. The chapter provides an overview of the genetic and antigenetic aspects of human histocompatibility systems. Histocompatibility antigens are the substances that are associated with the plasma membrane of tissue cells of some—but not all—members of a species. Tissue or cell suspensions carrying such antigens induce an immune response when introduced into another member of the same species. The immunity can be measured in several ways such as by the detection of antibodies in the serum of an individual rejecting a transplant, by a more rapid rejection of a second graft from the same donor, or by demonstration of increased immunological reactivity in lymphoid cells of the recipient. From immunological studies and from more limited chemical characterizations of antigens of different systems, it appears that a wide variety of substances can function as H antigens. In many respects, H antigens resemble blood group antigens with the distinction that blood group antigens are by definition found on the red cell and may also be present on other cells and tissues, whereas H antigens are found on tissues and may or may not be present on the red cell.