Essay, Research Paper: Xenotransplantation

Xenotransplantation


There is a shortage of organs for clinical transplantation all around the world.
Many patients waiting to receive new organs die because we are unable to receive enough
organs: there aren't enough donors. We are now testing the implantation of other
species'organs into the human body, that would be a great solution in ending organ
shortage. There is a problem though, the human body does not cooperate well with other
non-human organs. Rejection is the worst problem we have encountered yet. New
researches are helping us understand the mechanisms of trasplanting organs without
rejection. Cells or tissues from other species can be very usefull to the human race. They
can help cure some very deadly deseases such as cancer, AIDS, diabetes and liver failure.
This great technology can also bring disaterous effects to the human races. The
transplanted tissue can cary an unknown infection that may not harm that specie in
particular but might be deadly to humans. Also as a worse case scenario, an infection can
start a life-threatening pandemic. "The transplanting of animal organs, tissues, and cells
into human beings is likely to become more common in the future but such transplants
raises crucial issues that merit further investigation and discussion."(1)

There are atleast 50,000 patients waiting for transplant in the U.S.A but there are
less then 5,000 donors annually. If we can find a way to make our bodies accept organs
for other species, we will create a new "lifeline". However, xenotransplantation also
raises some medical, legal, and ethical issues. The concern of most doctors is the
rejection of the organs from the body and the birth of a new infection or disease. To find
out more on these possibilities, we have to monitor all patients who receive organs and all
the species who donate the organs but the species will also need screening for
"pathogens". A possible solution to minimize the risk of infection would be to raise
animals in an essentially germ free environment. However, if the animals are accidentally
released from the controlled environments, the whole experiment would be ruined.

Successful xenotransplantation would put an end to people on a waiting list.
People wouldn't have to wait years to receive an organ and people shouldn't die on a
waiting list. Some advocates say that successful xenotransplantation could save
thousands of lives because human organs aren't keeping up with demand. Back in 1994, a
bit over 7,600 people donated organs but there was 37,000 people on waiting lists and
50% of these people waiting to received an organ died before they received their organ.
Advocates also say that some religions may forbid some people in participating to
xenotransplantation. It is not in their beliefs. Then there is also animal rights group that
would cause problems. They are totally against the use of animals in scientific research.
Also what some people are starting to think is that if xenotransplantation works out well,
no one would volounteer on donating their organs but why would we still want human
donors if we can now implant organs from other species? There are also financial issues
as how much the hospital should charge and if the insuurance cmopanies should cover
this operation.

"The food and Drug Administration has already established a broadly constituted
advisory committee, including both expert scientists and lay representatives to examine
xenotransplantation.However, due to the aspects of public risk associated with
xenotransplantation, initial discussions must be focused on the ethical issues."(2)

There are a couple of things included in the legal issues. First of all there is the
Debate on the owner of the animal and the long term affect it will cause the animal. Also
if we artificially create an animal, how it will react to the natural world. Then, there will
also be some license fees for the use artificially created animals for their organs. This
types of laws are specifically excluded in U.S.A. and in Britain, but since the
"oncomouse" was patented in 1988, there now exist hundreds of laws for transgenic
procedures. Doctors are asking themselves if these are new inventions or rearrangements
of the genetic code. "Should laws of nature, animal, and human life be commodified in
this way?"(2)

We should always put up a caution on the possible long-term genetic problems.
Anything is possible and we have to be very cautious. Any little change in the genetic
code of animals is a cause for concern. The recent British experince of "the mad cow
disease" is evidence of this concern. To reduce these risks, we are now using transgenic
pigs as donors but there are only a few hospitals will be chosen as a center for
xenotransplant surgery. Other hospitals may be tempted to revive the xenotransplantation
program by using organs from baboons. It might advance their reputations, reduce the
cost to the patient and illiminate the license fees.

The biggest problem doctors are having with the transplant is that a body's
immune system reacts to these strange tissues and organs by destroying them. The two
materials (human and animal) are not compatible. If we try implanting a pig's liver in a
human body, within minutes it'll become a swollen and a blody mess. As soon as there is
a new organ implanted, our antibodies rap the organ and begin the "hyper-acute"
rejection process. Doctors and scientists find this a great "pitty" because the structure and
size of a pig's organ is a perfect replacement of a human organ.

A way that scientist are now using to control this rejection is to distract the
antibodies so they don't see the transplanted organ. One of the test they tried was "using
extra doses of culpable sugars to mop up antibodies before these antibodies can stick to
the xenograft." They got this idea because they had tried it on a baboon and it retained the
transplanted pig hart much longer then if they hadn't received these sugars intravenously.
But on a human, the amount of sugar needed to distract the antibodies will be poisonous.

Up to this date, every experiment failed either because the organ was rejected or
failed to function. In some cases, the use of immunosuppressive drugs to prevent
infections, led to infections. We are unable to prolong human life with transplanted
organs. But we are able to treat some other human illness with the use of animals. Pig
heart valves are routinely used un cardiac surgery, and insulin from cattle is used to treat
diabetes.