Doctors now say they have developed a technique that could free
many organ transplant patients from having to take immune system
suppressing drugs for the rest of their lives.
The treatment involves weakening the patient's immune system,
then giving the recipient bone marrow from the person who donated
the organ. In one experiment, four of five kidney recipients were
off immune-suppressing medicines up to five years later.
"There's reason to hope these patients will be off drugs for the
rest of their lives," said Dr. David Sachs of Massachusetts General
Hospital in Boston, who led the research published in Thursday's
New England Journal of Medicine.
Since the world's first transplant more than 50 years ago,
scientists have searched for ways to fool the body into accepting a
foreign organ as its own. Immune-suppressing drugs that prevent
organ rejection came into wide use in the 1980s. But they raise the
risk of cancer, kidney failure and many other problems. They also
have unwanted side effects such as excessive hair growth, bloating
and tremors.
Eliminating the need for anti-rejection drugs is "a huge
advance," said Dr. Suzanne Ildstad, a University of Louisville
immunology specialist who had no role in the work.
"It still needs some fine-tuning so that everyone who gets
treated gets the same consistent outcome ... It's not the holy
grail of tolerance yet," she cautioned.
In the 1990s, Sachs showed the treatment could work in a kidney
recipient who was a good genetic match. The woman, who had an organ
and marrow transplant in 1998, has not needed anti-rejection drugs
for a decade.
The new study involved five people who got kidneys from parents
or siblings who had slightly different tissue types from the
patients. Since many kidney transplants are similarly mismatched,
there is hope more people might one day be spared
immune-suppressing drugs.
(Xinhua News Agency January 25, 2008)