- 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
- The panel made clear that the government
is anxious to avoid any chance that people could catch viruses from transplanted
- 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
- ``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
- 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