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Many scientists believe that the advent of genetic engineering
techniques, combined with the use of animal-to-human organ
transplants, raises some important scientific as well as ethical
questions.
There is now a very real risk of creating new and catastrophic
human epidemics through the proposed transplanting of animal
organs (genetically engineered or otherwise) into humans,
thereby giving rise to the possibility of unknown viruses
crossing the species barrier - a single instance of which
could unleash an irreversible chain reaction of unimaginable
proportions upon the world.
Common sense should tell us that transgenic transplantation
(or xenotransplantation) actually represents one experimental
technique (the production of transgenic animals) superimposed
on yet another experimental technique (the transplantation
of organs into human beings). This situation translates into
a statistical nightmare, since there is an exponential increase
in unknown risks.
The danger of transmitting known as well as unknown viruses
and bacteria from animals to man is a matter for major concern.
Even the use of SPF (specific pathogen-free) animals, thoroughly
tested as they are for known diseases, cannot eliminate this
risk.
Jonathan Allen, a virologist at the South-West Foundation
for Bio-Medical Research in San Antonio, Texas, was recently
quoted as saying:
"This is a big mistake. It only takes one transmission
from one baboon to one human to start an epidemic. There's
no way you can make it safe."
Are we risking another AIDS epidemic?
Professor Gianni Tamino, Professor of Biology at the University
of Padua, Italy, and European Deputy of the Italian Parliament
for the Green Party, denounces this research on the grounds
that it ignores "the danger of transmitting a virus from
one species to another, with the resultant spread of new and
unforeseeable epidemics like that of AIDS, which is generally
held to have been generated by a mutation in the SIV virus
transmitted from monkey to man."
A horror-film scenario...
In 1992, Thomas E Starzl (one of the pioneers of transgenic
transplants at the University of Pittsburgh, USA) transplanted
a baboon liver into an HIV patient suffering from Hepatitis
B. The patient survived for 70 days. His case history reads
like a horror-film scenario.
"By turns, he suffered from septic intoxication, oesophagitis,
viraemia (the presence of viruses in the blood), haemmorhaging
in the pleural (chest) cavity, and later from circulatory
collapse, as well as an acute cough. In the end, kidneys
and liver failed, and a bile engorgement was produced. The
patient finally died from internal bleeding."
The growing call for caution
Many researchers are now calling for caution. According to
the German magazine Der Spiegel, Claus Hammer of the University
of Munich (probably Germany's most prominent xenotransplant
expert) said:
"Defensive reactions depend on a multitude of additional
biochemical and physiological factors. One of these is the
presence of natural congenital antibodies, which are a vital
element of the immune system - yet they still turn out to
be shrouded in mystery."
More and more scientists are warning of the possible danger:
"The potential risk to public health - therefore also
to patients' rights - from these transplants would appear
to far outweigh the questionable benefits from such experimental
procedures."
Alternatives to transgenic transplants
At present, the most appropriate source of organs for transplantation
is the human being, but, as demand far outstrips supply, the
solution would be to decrease the demand, or to increase the
supply, or both. One way of decreasing the demand would be
to implement primary preventive health campaigns on a far
greater scale than at present, commencing at as early an age
as possible, based on current knowledge in the field of preventive
medicine, both conventional and complementary.
We also need to redefine health in positive terms as
'glowing health', and not simply the absence of disease, in
order to emphasise the idea behind true preventive medicine.
This approach, coupled with the currently available organs
from human donors, could go a long way towards fulfilling
the needs of transplant patients.
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