This article is dated by a few months....but very interesting coverage of what BTRN is trying to do. One can hope the last two paragraphs of this article, isn't the case....
"This Little Piggy Goes to Steve
by Kristen Philipkoski
2:00 a.m. Feb. 27, 2001 PST
It may be a while before pigs can fly, but it may take only three years before researchers convince the FDA to approve the transplantation of pig organs into humans.
Transplanting organs from animals to humans holds the promise of saving the lives of thousands, maybe millions, around the globe. Past failures in the field, however, have made the FDA wary of approving new techniques.
But researchers at BioTransplant in Charlestown, Mass., said that with their license to a new patent, they'll soon have enough data to convince the FDA to approve clinical trials.
"Over the next three years we'll develop the data that can support going into clinical trials," said Elliot Lebowitz, president and CEO of BioTransplant.
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That could be optimistic. Critics of transplanting organs -- a technique called xenotransplantation -- say it will be at least 10 years before it's clear how dangerous it might be to transplant animal organs into humans.
Still others -- citing recent deaths in the field and the prospect of spreading new diseases -- are calling for the ban of xenotransplantation altogether.
But BioTransplant's new technique is different than those previously used.
Just as researchers have decoded the map of the human genome, Dr. Jay Fishman -- a physician in Infectious Disease and Transplantation at the Massachusetts General Hospital and an associate professor of medicine at Harvard Medical School -- has sequenced and patented the genetic makeup of the porcine endogenous retrovirus, also known as PERV.
In 1997, researchers showed that PERV can jump from pig to human cells in test tubes.
BioTransplant has licensed the genetic sequence, allowing its researchers to identify PERV and keep the virus out of their pig organs.
The patent covers the PERV genetic sequence as well as any test they develop to identify it. The research was funded by biotech giant Novartis, which is collaborating on the project with Massachusetts General and BioTransplant.
"What's important is once you know the code in terms of the alphabet that makes up this virus, you could detect the virus if it were in a pig or human patient, and also you could develop the ability to delete the virus," said Biotransplant's Lebowitz.
Alix Fano, director of the Campaign for Responsible Transplantation (CRT), is skeptical.
"I think any statements that are made by these companies have to be taken with a grain of salt, because we've heard these proclamations since the early '90s."
CRT is an international coalition of physicians, scientists and 90 public interest groups, including the Physicians Committee for Responsible Medicine, the International Center for Technology Assessment, the New Mexico Center for Chronic Disorders, the Jane Goodall Institute and the Earth Island Institute.
Xenotransplantation has had a spotty history. Surgeons in California in 1984 transplanted a heart from a baboon into a newborn girl, who died after 20 days. In 1992, surgeons at the University of Pittsburgh Medical Center transplanted the liver of a baboon into a critically ill patient. He died 71 days later of a brain hemorrhage, but surgeons said the liver was still functioning at the time. Also in 1992, a pig liver was transplanted into a woman dying of hepatitis. She died a day and a half later.
Since then, the FDA has been more cautious about the approval of human studies involving transplanting whole organs from animals to humans. There are at present no human clinical trials involving the transplantation of whole organs from animals to humans, said FDA spokeswoman Lenore Geld.
Animal cells have been successfully used to cleanse the blood while patients are waiting for a human transplant, and in other technologies to grow skin to treat severe burn victims. Treatments using pig cells are also in clinical trials to treat Parkinson's disease.
But viruses have also been transferred from animals to humans, and critics fear xenotransplantation could introduce into humans dangerous, unknown viruses with no known cures.
The CRT believes animal-to-human transplantation should be banned, and is suing the FDA for allegedly withholding information about xenotransplantation clinical trials and for hiding dangers.
But xeno advocates believe it will eventually become a safe and effective procedure.
In a paper presented at a meeting of the American Society for Microbiology in May 2000, Fishman, who performed the research, said that cross-species transplantation might be safer than human-to-human transplantation, because certain human viruses might not grow in tissues from other species.
"Due to the species differences between the host (human) and donor (non-human species), the risk of infection of the transplanted organ ... may actually be decreased. This includes common pathogens such as cytomegalovirus, Epstein-Barr virus, human herpes viruses 6,7 and 8, hepatitis B and C, and possibly human immunodeficiency viruses, and even HIV 1 and 2," he wrote.
Besides the license to the PERV gene sequence, BioTransplant researchers have also bred pigs that the researchers say are incapable of passing on the porcine retrovirus to humans.
"We've developed a strain of inbred miniature swine that are so similar that you actually could take skin from one and it would be accepted by another," Lebowitz said.
Besides not transmitting the virus, the miniature swine are also closer in size to humans than regular pigs, so their organs would be better suited for transplants, he added.
Fano of the CRT doubts the swine are free of PERV.
"Every animal has hundreds of retroviruses and there's no way you can breed them out," she said. "And there could be other viruses lurking in these pigs, not to mention parasites, bacteria, fungi and latent infections of all kinds."
"All patients who have had these transplants have died," Fano said. "There's no indication from the animal studies that anything has changed." |
