Xenotransplantation

Shortages in the number of available donor organs continue to force the transplant community to seek alternative options in an effort to meet the high demand. Cross species, or xenotransplantation, using swine as potential donors, has long been hypothesized as a potential attractive strategy for solving the organ shortage crisis due to the supply of available donors, as well as anatomical and physiological similarities between swine and humans. Early studies with wild-type swine donors were limited due to shortened survival as a result of acute humoral xenograft rejection due to circulating preformed antibodies. The eventual development of a-1,3-galactosyltransferase knock-out swine donors in the early 2000s has been critical in advancing preclinical xenotransplantation research, and more recently through significant improvements in genetic engineering technology such as CRISPR/Cas9, the development of multitransgenic swine donors has allowed xenotransplantation to progress closer to becoming a clinical reality. Here, we provide a brief overview of early clinical xenotransplantation experience, followed by major technological advances and current barriers to solid organ (kidney, liver, heart, and lung) and islet cell xenotransplantation.