Animal Organ (And Disease!) Transplants Coming
From Liz Edwards
By Maggie Fox, Health and Science Correspondent
ROCKVILLE, Md Dec 17 (Reuters) - Companies seeking to develop methods of transplanting animal organs or tissues into people will have to meet the very highest standards of testing, a U.S. Food and Drug Administration panel warned on Wednesday.
The panel made clear that the government is anxious to avoid any chance that people could catch viruses from transplanted animal organs.
The issue of xenotransplantation, or animal-to-human transplants, is a hot one. On the one hand, the transplants offer to fill a huge gap between the numbers of people who need transplants and the numbers of organs available.
On the other hand, there is the danger that viruses and other infections from the animals could pass to humans and start unforeseen epidemics.
And finally, there are the ethical issues.
``Our need for advice has perhaps never been greater than with the issue of xenotransplantation,'' Mary Pendergast, senior adviser to the commissioner of the FDA, told a meeting of the agency's xenotransplantation subcommittee.
``We are at the cusp of a possible explosion of new xenotransplantation efforts,'' she said.
``Yet ... the science of xenotransplantation is still evolving and there is much we do not know about the risks of xenotransplantation ... The field will not stand still as we wonder what to do.''
The panel is being asked to decide whether tests of animal-to-human transplants should be allowed and if so, how they should be structured.
Pig organs are the most likely candidate, as pigs are similar in size to humans and are easily bred. But recent reports make clear that pigs carry viruses known as porcine endogenous retroviruses.
These viruses, like other so-called endogenous viruses, have made themselves part of the pig's genetic make-up and cause no symptoms in pigs. The worry is that they would pass to people getting transplants and make them ill.
Under the worst scenario, they would mutate in people and cause epidemics. The HIV virus that causes AIDS is believed to have originated in animals.
``I think there is no question these
viruses can be pathogenic in primates, if the virus really takes off,'' said Robin Weiss, an expert in viruses and cancer at Britain's Institute of Cancer research.
Therefore, companies that want to develop the technology had better test carefully, Pendergast told the meeting.
``This is a technology where we will expect the very best from industry and technicians,'' she said. ``We cannot regulate xenotransplantation without full discussion by all interested parties.''
Pendergast said this may require an ``uncomfortable openness.'' She added: ``If you don't want your work in progress to be publicly discussed and assessed, then you'd best find a new field.''
Dr. Corinne Saville of Imutran, a company based in Cambridge in Britain said Imutran wants to test xenotransplants. She the company outlined a proposal for checking to see how dangerous pig tissue might be, starting with tests in primates.
Saville said Imutran, owned by Novartis, had found more than 100 human patients around the world who had been treated with live pig tissue, from skin grafts to transplants of pancreatic cells. The company was getting blood samples and testing them for the virus.
``We would advise a stepwise and cautious approach,'' she said. ^REUTERS@
19:01 12-17-97

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