Xenotransplantation

Xenotransplantation
Long axis echocardiography. Representative long axis view echocardiography, four weeks after myocardial infarction (MI), right before CMPC/placebo infusion. Thinning and akinesia of the septal apical wall due to MI can be appreciated.
MeSHD014183

Xenotransplantation (xenos- from the Greek meaning "foreign" or strange[1][2]), or heterologous transplant, is the transplantation of living cells, tissues or organs from one species to another.[3] Such cells, tissues or organs are called xenografts or xenotransplants. It is contrasted with allotransplantation (from other individual of same species), syngeneic transplantation or isotransplantation (grafts transplanted between two genetically identical individuals of the same species) and autotransplantation (from one part of the body to another in the same person).[citation needed] Xenotransplantation is an artificial method of creating an animal-human chimera, that is, a human with a subset of animal cells. In contrast, an individual where each cell contains genetic material from a human and an animal is called a human–animal hybrid.[4]

Patient derived xenografts are created by xenotransplantation of human tumor cells into immunocompromised mice, and is a research technique frequently used in pre-clinical oncology research.[5]

Human xenotransplantation offers a potential treatment for end-stage organ failure, a significant health problem in parts of the industrialized world. It also raises many novel medical, legal and ethical issues.[6] A continuing concern is that many animals, such as pigs, have a shorter lifespan than humans, meaning that their tissues age at a quicker rate. (Pigs have a maximum life span of about 27 years.[7]) Disease transmission (xenozoonosis) and permanent alteration to the genetic code of animals are also causes for concern. Similarly to objections to animal testing, animal rights activists have also objected to xenotransplantation on ethical grounds.[8] A few temporarily successful cases of xenotransplantation are published.[9]

Bioprosthetic artificial heart valves are generally pig or bovine-derived, but the cells are killed by glutaraldehyde treatment before insertion,[10] therefore technically not fulfilling the WHO definition of xenotransplantation of being live cells.[3]

  1. ^ Dooldeniya, M D; Warrens, AN (2003). "Xenotransplantation: where are we today?". Journal of the Royal Society of Medicine. 96 (3): 111–117. doi:10.1177/014107680309600303. PMC 539416. PMID 12612110.
  2. ^ Mitchell, C Ben (2000-05-10). "Xenotransplanation and Transgenics: The Need to Discuss Limits". Cbhd. Archived from the original on 2018-11-19. Retrieved 19 November 2018.
  3. ^ a b Xenotransplantation. Definition by the World Health Organization
  4. ^ Sarah Taddeo, Jason S. Robert (2014-11-04). ""Hybrids and Chimeras: A Consultation on the Ethical and Social Implications of Creating Human/Animal Embryos in Research" (2007), by the HFEA". The Embryo Project at Arizona State University.
  5. ^ Cite error: The named reference Tentler 2012 was invoked but never defined (see the help page).
  6. ^ Kress, J. M. (1998). "Xenotransplantation: Ethics and economics". Food and Drug Law Journal. 53 (2): 353–384. PMID 10346691.
  7. ^ Hoffman J, Valencak TG (2020). "A short life on the farm: aging and longevity in agricultural, large-bodied mammals". GeroScience. 42 (3): 909–922. doi:10.1007/s11357-020-00190-4. PMC 7286991. PMID 32361879.
  8. ^ "Interviews - Dan Lyons". PBS. Retrieved May 21, 2022.
  9. ^ "Organ Transplants from Animals: Examining the Possibilities". Fda.gov. Internet Archive. Archived from the original on December 10, 2007. Retrieved May 21, 2022.
  10. ^ Li KYC (2019). "Bioprosthetic Heart Valves: Upgrading a 50-Year Old Technology". Front Cardiovasc Med. 6: 47. doi:10.3389/fcvm.2019.00047. PMC 6470412. PMID 31032263.