Trying to transplant
A team of modern transplant surgeons |
The history of organ transplantation goes back a very long way.
People recognised centuries ago that if they could replace damaged
or broken body parts many people would be healed. But progress
was very slow, because some very sophisticated science needed
to be unravelled before successful transplants really became a
possibility. In spite of this some early attempts were made.
In 800BC there is a report by some potters in India that a surgeon
called Susrata grafted new noses onto people using flaps of skin.
From around 200AD in China there are reports of Hua-To replacing
diseased organs with healthy ones. But genuine transplants, where
a new organ is placed in the body of the recipient and restores
them to a healthy way of life, have been a long time coming.
|
The compatibility question
Before transplants could help people overcome the problems of a failing
organ, scientists needed a better understanding of the human body. An
important step was developing an understanding of the human immune system.
The immune system has as its basis a method of recognising cells. It
can tell the difference between the cells of a person's body and all
other cells. The immune system will reject and destroy transplanted
organs because it recognises them as different. This meant that not
only did scientists and doctors have to develop the surgical techniques
for successful transplants, but they also had to find ways (for example
using special drugs) of preventing rejection of the new organ. Throughout
the first fifty years of the last century doctors and scientists were
gaining in knowledge and understanding of how the organs of the body
worked. They were also learning to recognise some of the signals used
by the immune system. Sir Peter Medowar, often known as the father
of modern immunology, did a great deal of pioneering work with skin
grafts during World War II, leading to a far deeper understanding of
the problems of rejection. Scientists and doctors were working towards
the point where they would be able to transplant organs from one person
to another, but this was always going to be an enormous leap in the
dark. The patients would be very sick, indeed dying people - yet if
the organ transplant failed to save them the technique would be seen
as a failure.
Preventing rejection using drugs
In 1969 scientists in America and Norway discovered a fungus which was
to have far-reaching effects on the success of transplant surgery in
the future. In 1972 Jean Borel, working in Switzerland, found that a
chemical called cyclosporine which could be isolated from the fungus
had immunosuppressant properties - in other words, it damped down the
reaction of the immune system. By 1980 this 'wonder-molecule ' had been
synthesised for the first time and by 1983 it was approved for commercial
and clinical use. When cyclosporine is given to patients after a transplant,
the risk of rejection is greatly reduced because the activity of their
immune system is lowered.
Transplant patients have to take their immunosuppressant drugs for
the rest of their lives , because the body never gets used to the new
organ and accepts it. The main downside of drugs like this is that they
suppress the whole immune system making the people taking them more
vulnerable to normal infections. However, because everyone is aware
of this, transplant patients are simply carefully monitored and given
other medicines to help them if they develop an infectious illness.
Transplanting kidneys
The big one - transplanting hearts
Stem cell research
Organ transplants timeline
|
ctivity
1
