CLINICAL XENOTRANSPLANTATION OF SOLID ORGANS

A possible solution to the chronic shortage of allografts is xenotrans plantation, the use of tissue from an animal donor. Most experts belie ve that the pig will provide the most suitable solid organs for use in human beings. Although porcine organs are rapidly rejected by a proce ss called hyperacute rejection (HAR), there is hope that several novel therapeutic strategies, already tested in animal models, will overcom e this hurdle in patients. Successful clinical trials of these strateg ies, expected within the next few years, may herald the era of clinica l xenotransplantation. However, there is increasing evidence that othe r barriers, both immune and non-immune, might exist to limit the survi val of xenografts beyond the HAR phase. Mew strategies to overcome the se barriers will be needed if long-term xenograft survival equivalent to, or better than, that of allografts is ever to be achieved.