Recent strategies to overcome the hyperacute rejection in pig to human xenotransplantation.

Due to the ever increasing shortage of suitable human donors, alternative strategies are sought to moderate the current discrepancy between the number of executable and required transplantations. Xenotransplantation (i.e., the transplantation of organs [tissues or cells] between different species) appears to be a reasonable solution. However, various problems (immunological, physiological, infectious-microbiological, ethical-juridicial) seem to be associated with xenotransplantation. One of the most formidable barriers to xenotransplantation is the phenomenon of hyperacute rejection that may lead to the destruction of the transplanted vascularized organ in a few minutes to hours. In the pathogenesis of hyperacute rejection, xenoreactive antibodies and the complement system appear to be of primary importance. Various methods can be applied to prevent hyperacute rejection; both the recipient and the donor can be treated. In this brief review, the author attempts to present a synopsis of the possible therapeutical interventions to prevent hyperacute rejection..