Alloantigen

Alloantigens are antigens present in some but not all members of a species, arising from genetic differences between individuals. They trigger immune responses when there is exposure to non-self antigens from the same species, as during transplantation, transfusion, or pregnancy[1][3][5]. Two major classes of alloantigens include blood group antigens and histocompatibility antigens (such as the major histocompatibility complex, or HLA, in humans)[1][3]. The immune response to alloantigens is the basis for graft rejection and transfusion reactions, mediated by direct, indirect, or semidirect pathways of T cell and antibody recognition[2][4][7]. Alloantigen is not an actionable single molecular target but encompasses a range of antigens differing between individuals, most notably in transfusion and transplantation medicine[1][3][5].

Other names

allogeneic antigenisoantigen