Heart and Lung Xenotransplantation

The relative scarcity of useable donor heart and lung allografts has led to a high waitlist mortality, prompting the search for alternative sources of donor organs. Xenotransplantation holds the promise of an unlimited supply of readily available and optimally functioning organs. This chapter reviews the history, current state, and future of xenotransplantation as a potential solution to address the insufficient supply of donor organs. Hyperacute rejection is a form of humoral rejection and is driven by the presence of natural, preformed antibodies targeting xenoantigenic epitopes on porcine endothelial cells. Advances in immunosuppressive therapies specifically targeted at key pathways in xenotransplantation have contributed significantly to improved xenograft survival. Ex vivo perfusion of pig organs with whole human blood allows the efficient and comprehensive evaluation of pig-human immune interactions and has been utilized extensively as a preclinical model in thoracic xenotransplantation.