Pigs Cloned with Organs That Are Safe for Human Recipients

January 4, 2002 (AP) - In a major advance that could lead to using pigs as a source of organs for people, two groups of scientists said this week that they had cloned pigs whose organs lack a genetic trait that prompts the human body to reject them. Using a toolbox of new technology - from genetic screening to cloning - the research teams created the first piglets without a gene that produces a certain sugar, a substance that signals the human immune system to attack the cells making it.

With a bit more genetic tinkering, researchers believe they can make pig hearts and kidneys that the human immune system would tolerate. "It's a milestone because this is the first time we've been able to make a specific genetic modification in pigs," said Randall S. Prather, leader of a team at the University of Missouri that published its results Thursday in the journal Science. Another group from PPL Therapeutics Inc. in Virginia announced similar findings in a news release Wednesday but has yet to publish its results.

The use of animal organs for human patients -- a technique called xenotransplantation - could one day transform treatment for the more than 70,000 Americans on waiting lists for scarce human organs. Some experts believe the technology has the potential to spawn a $6 billion industry, providing an abundant source of new hearts, pancreatic cells for diabetes patients, livers, and kidneys.