Process in the study of immunology and potential risks of xenotransplantation

Abstract

Great success in clinical allotransplantation recently has caused the shortage of available organs from deceased human donors. This crisis could be resolved by the use of organs from an anatomically suitableanimal, such as the pig. However, multiple hurdles need to be overcomed, including immunologic barriers, physiological differences and ethical concerns between pigs and humans. The hyperacute rejection was the first immunological barrier. Now it has recently been prevented by the breeding of pigs that do not express galactose-α1 ,3-galactose (Gal). In addition, there are other antipig antibodies against non-Gal or unidentified antigenic targets that may well be involved in graft destruction, including N-glycolylneuraminic acid and so on. Besides the immunological barriers, potential risks for infection transmitted from the xenograft donor to the recipient have also been investigated. Thus far, clinical xenotransplantation of pig tissues has not resulted in the transmission of viral infection to humans, significant risks for disease transmission from swine to humans have not been confirmed. If immunologic hurdles can be overcomed, it is reasonable to initiate carefully monitored clinical trials. Key words: Xenotransplantation ; Galactose-α1, 3-galactose; Porcine endogenous retrovirus