Abstracts
Résumé
La pénurie d’organes disponibles est responsable d’un nombre croissant de décès de patients en attente de greffe. Dans ces conditions, des solutions alternatives sont envisagées, notamment l’utilisation d’organes porcins. Les xénogreffes sont cependant soumises à différents types de rejet (hyperaigu, vasculaire aigu et cellulaire) dont les mécanismes commencent à être mieux connus. Les stratégies visant à faire de la xénotransplantation une réalité clinique existent et, bien que le nombre de laboratoires engagés dans ce domaine soit encore modeste, des progrès substantiels ont été récemment obtenus. Elles incluent de nouvelles modifications génétiques des animaux donneurs combinées à la mise au point de traitements immunosuppresseurs adaptés à la situation clinique, ainsi que les tentatives d’induction d’une tolérance immunitaire et la gestion du risque sanitaire. L’acceptation des xénogreffes par les receveurs potentiels et son impact sur la société sont également pris en considération.
Summary
Transplantation represents a major advance in modern medicine with a major impact on the interactions between individuals and society. The numbers of patients undergoing organ transplantation increased steadily over the years and around 250,000 individuals are living nowadays in Europe with a transplanted organ. On the other hand, the numbers of cadaveric (brain-dead) donors used for organ transplantation remains stable, at around 5,000 each year, and the numbers of transplantation from living donors only slowly increase in Europe. Therefore, a gap is growing between the numbers of patients in need of a transplant and the numbers of organs available for transplantation. About 45,000 patients are currently on renal transplant waiting lists in Europe and, depending on the countries considered, 15 to 30 % of candidates for liver or heart transplantation die before a life-saving transplant becomes available to them. There is therefore an urgent need to implement innovative research and to take full advantage of recent biotechnological advances to explore new avenues in xenotransplantation, and to simultaneously address the ethical, societal and public health issues related to organ replacement. Much progresses have been accomplished in the understanding of xenograft rejection processes that include hyperacute, acute vascular and cellular rejection mechanisms. Strategies to promote xenograft survival that are currently under evaluation include genetic engineering of donor pigs, adapted immunosuppressive treatments and tolerance induction. Also, the psychological acceptance has been evaluated.
Appendices
Références
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