XENOTRANSPLANTATION - CLINICAL-TRIALS AND PERSPECTIVES

Despite the reticence of certain prominent scientists, there will be n o moratorium on clinical xenotransplantation in the USA and a limited number of well-controlled trials will be enabled. There has already be en some advances in cell and tissue xenografts with encapsulated porci ne pancreas cells and porcine foetal neurones in patients with diabete s and Parkinson's disease. However, because oi some porcine viruses ar e able to develop in human tissues, current and planned trials have be en interrupted until routine Viral detection tests are available. Seve ral attempts have been made in the past with animal organs (kidney, he art liver) from various non-human primate species and conventional imm unotherapy without success. Another major question now, is the choice of the animal donor species. Phylogenetically close to man, non-human primates would be a right and logical choice. But because of their pro curement problems, it is likely that most future trials will be conduc ted with porcine organs from more performant transgenic animals, more powerful immunosuppressors and new therapeutic strategies based on the natural tolerance mechanisms.