BACKGROUND: Transplantation of organs is a well-known and accepted life-saving procedure for end-stage kidney, liver, heart and lung diseases. The insufficient number of donor organs limits the application of this technique and leads to unnecessary loss of life. Experimental techniques such as xenotransplantation are extremely important to determine new methods of creating organ availability.
DATA SOURCES: A literature search of Pubmed database was conducted and research articles reviewed.
RESULTS: Xenotransplantation is a progressive field of research. Human complement regulatory protein (hDAF)transgenic pigs and new immunosuppressive strategies that reduce xenoreactive αgal antibodies, have decreased rates of acute vascular rejection. Transplantation of α-1, 3-galactosyltransferase knock-out pig organs into baboons has resulted in the longest graft survival to date. Coagulation pathways have been identified as having a role in graft rejection. In vitro studies of porcine endogenous retroviruses (PERVs) show encouraging results that zoonosis will be less hindering to xenotransplantation than once thought.
CONCLUSIONS: Several recent advances in xenotransplantation research have brought this technique closer to clinical application. The Ethics Committee of the International Xenotransplantation Association has made recommendations to ensure maintenance of ethical standards. Advancement will depend on the development of pig models, novel immunosuppressive strategies to target the innate immune system, and new ways to create donor specific tolerance. Prevention of rejection and transmission of infectious agents remain unresolved issues. In the future, it is feasible that xenotransplantation will be used to resolve this medical dilemma.