Pigs- dinner or lifesavers???

Today, approximately 3000 Australians are in need of an organ or tissue transplant however very few people are actually organ donors. Recently, pigs have been proposed as a transplant organ source. This is due to the fact that pigs are physiologically one of the closest animals to humans; they are easy to breed and are generally quite a healthy species. In order for this proposal to become a success many obstacles both ethical and scientific have to be overcome.

The biggest challenge in using animal organs for humans is stopping the immune system from rejecting the foreign tissue (hyperacute rejection). Specifically, pigs carry a gene (known as 1,3-galactosyltransferase) which humans do not and when introduced human antibodies will recognise the molecule as foreign and eventually destroy the cells. To counteract this problem, scientists have genetically engineered pigs that no longer carry the gene.

Other factors that need to be considered before pigs become common organ donors are ensuring illness such as the common porcine endogenous provirus are not transferred from pig to humans. Also the life span of a pig is commonly 30 years. Scientists need to determine if it is possible to extend the usage of a pig’s heart. Finally, moral objections to killing pigs need to be kept in mind. If satisfactory solutions are found for these hurdles pig transplants could be a huge advancement in human health.

By Jessica Spirou

References:

Primary:
McDowell, N., 2003. Mini-pig clone raises transplant hope. New Scientist 16, 35

Secondary:
Stolberg, S. (2002) Breakthrough in pig cloning could aid organ transplant, The New York Times, New York.

Interest Websites:
· Organ donor Statistics
· Xenotransplantation information