Humans may be alive with pig organs

Scientists may be just five years away from keeping human patients alive with pig organs, it has been revealed. The biggest obstacle in the way of safe transplants is close to being swept away by new advances.

As a result xenotransplantation - placing animal organs into humans - is back on the agenda, said expert Dr Anthony Warrens, from Imperial College, London. Normally planting a pig organ such as a kidney in a human triggers an immediate and deadly immune response.

Attempts have been made to breed "safer" pigs but with little success. Patients given organs from these animals would still need their immune systems to be strongly depressed. But now scientists believe it should be possible to trick the immune system into not recognising or tolerating foreign pig tissue.

One way is to produce pigs lacking a sugar called "gal epitope" which is targeted by immune system antibodies. Another is to mimic the natural process by which the body learns to inactivate cells that might attack parts of itself. Experiments using both strategies have allowed pig kidney transplants to survive in lab animals for more than 80 days, Dr Warrens told the BA Festival of Science at Trinity College, Dublin, Daily Mail reports.