Saved by the Animals?
March 2, 2001 (Washington) -- At the University of Pittsburgh, researchers are preparing to test live liver cells derived from pigs to help clean the blood of about 15 patients with acute liver failure.
One of the first human experiments approved by federal regulators to evaluate whether live animal cells can functionally replace a failed human organ, the Pittsburgh experiment could lead to a way to alleviate the nation's desperate need for organ transplants.
The experiment will help establish whether animal cells and organs actually can perform the same critical functions as human cells and organs -- a question that continues to plague the emerging field of xenotransplantation, the official name given to the process of replacing ailing human organs, such as livers, kidneys, and hearts, with live animal organs.
According to a report released earlier this month by the nation's organ transplant network United Network for Organ Sharing, the number of people waiting for an organ transplant increased more than five times as fast as the number of transplantations.
So far, five patients have been recruited for the Pittsburgh study, which is sponsored by Minneapolis-based Excorp Medical Inc.
"The principal reason that we believe the technology is likely to be efficacious is the results from our animal studies," Daniel Miller, PhD, president of Excorp Medical, tells WebMD.
In those studies, the researchers used the same pig liver cells to prolong the lives of dogs with liver failure.
Although the results of the human studies are likely to differ, Miller says these animal studies demonstrated that pig liver cells are at least likely to mimic their human equivalents.
"The concept is sound," he tells WebMD.
Given that about 40,000 Americans die each year from liver failure, the process also could prove to be a lifesaver for the estimated 17,000 Americans currently awaiting a liver transplant.
A mere 4,500 human livers become available for transplant each year.
This growing demand for organs also is what spurred Miller's interest in the process and what is spurring the general interest in xenotransplantation.
Despite progress in the field, some experts question whether xenotransplantation will ever become a viable solution for the organ shortage.
The primary concern? The lack of any real assurance that using animal organs in humans is safe and will not lead to the emergence of a potential new virus.
Xenotransplantation could increase the risk of creating a novel virus because it breaches traditional barriers between animals and humans, such as the skin, explains Alix Fano, MA, executive director of the Campaign for Responsible Transplantation, an international coalition that wants to ban further research into xenotransplantation.
"That's unacceptable when you consider that animal viruses have the potential to wreak havoc on human populations," she tells WebMD.