ABSTRACT
Xenotransplantation, the use of organs or tissues from disparate species (pigs to humans in the case of this chapter), has been a focus of research by many groups for the past several decades. Xenotransplantation is a potential solution for the continued organ shortage in clinical transplantation. However, the immunological barriers that need to be overcome (discussed later in the chapter) continue to be signicant despite advances in the prolongation of the survival of swine organs into nonhuman primates (NHPs). The scientic hype in the eld of xenotransplantation of the past 20 years is becoming less positive; however, the use of xenogeneic cells (like pancreatic islets) and acellular tissues (such as heart valves) are currently showing promising results. While vascularized organs and tissues can conceptually reach clinical application (Ye et al. 1994, Dorling 2002, Alisky 2004), key immunological obstacles must rst be overcome before translation into humans. The use of transgenic technologies, which humanize swine organs and minimize rejection, continues to be a major focus of research. Thus, successful xenogeneic organ acceptance will require a combined strategy using transgenic manipulation and improvement of immunosuppressive agents since the current level of immunosuppression required to prevent acute/hyperacute rejection in xenogeneic swine to baboon studies continues to be lethally toxic. The development of “humanized” swine using transgenic technologies in combination with immunological tolerance by the re-education of the immune system (Yang and Sykes 2007) is likely the most clinically promising approach. Conceptually, this would permit the recipient to be
Introduction ....................................................................................................................................405 Swine as a Xenogeneic Donor .......................................................................................................406
