Xenotransplantation

Abstract
Background: Over the past 10 years xenotransplantation has generated much interest in the hope that it will enable us to overcome the current lack of human organ donors. This review examines the evolution and current therapeutic strategies that have been developed to overcome the predominant problem of graft rejection. Methods: A literature review was undertaken using a Medline search from January 1966 to August 1999. Results and conclusion: Despite the considerable advances that have been made in molecular biological techniques, xenograft rejection cannot be prevented without significant immunosuppression and toxic side-effects. The problem of delayed rejection, in particular, will probably be very difficult to overcome, although some of the difficulties associated with hyperacute rejection have been resolved. The potential risk of porcine endogenous retrovirus transmission has generated much debate recently, but it is likely that some of the important issues relating to xenotransplantation will never be resolved until carefully regulated clinical trials are allowed to begin.