| June 27, 2000
NEW HAVEN, Conn. (AP) - Liver cells have been found to come
from an unlikely source - bone marrow - raising the
possibility that people with hepatitis and other liver
diseases could somehow use their own cells to heal themselves,
a new study found.
The study also increases the understanding of stem cells:
free-agent cells in the body that scientists believe have the
capacity to convert into several kinds of organ cells.
"This breaks all the boundaries we're taught in medical
school. This isn't supposed to happen," said researcher Dr.
Neil Thiese. "Organs are separate things - they work together,
but one does not become the other - that's always how we've
looked at it."
The study by Thiese, from the New York University School of
Medicine, and Dr. Diane Krause, from the Yale School of
Medicine, was published this month in the journal Hepatology.
Krause said Monday that the discovery has definite benefits
for people with liver disorders.
It's not that far-fetched to think that doctors will be
able to take bone marrow from a patient with a liver
condition, treat it and put it back into the patient so the
new cells can treat the person's own liver, Krause said.
"The clinical applications are not difficult to imagine.
I'm certain this will come to fruition. I'm not sure when,"
she said.
The study used female patients who had undergone bone
marrow transplants from male donors, and male liver disease
patients who had liver transplants from female donors.
A green-glowing stain was used to light up the Y
chromosomes in the cells - chromosomes that are found only in
men. Researchers could analyze the livers of the test subjects
to see where the liver cells were coming from.
Doctors found that the women who got bone marrow
transplants from men had some Y-chromosome liver cells. In one
woman, 17 percent of her liver cells were male a year after
the bone marrow transplant.
The only place the Y-chromosome cells could have come from
was the male bone marrow, the study said.
The men, who got liver transplants from female donors, also
had Y-chromosome liver cells on their female livers. In one
man, 40 percent of his liver had Y chromosomes.
The liver has long been known to regenerate and repair
itself, but it was assumed before that the new cells were just
coming from the liver, Thiese said.
The liver is the body's main chemical factory. It regulates
the levels of chemicals in the blood, helps filter out poisons
and produces proteins for blood plasma that help the immune
system and help blood coagulate.
Diseases that affect the liver include hepatitis, which
comes in various strains and appears in epidemic proportions
in the U.S.
Dr. Adrian Di Bisceglie, the medical director of the
American Liver Foundation, said the study may lead to
practical applications someday to help people who have liver
ailments.
"Obviously, there's a leap from these data to clinical
applications," he said.
For people with genetic liver problems, gene therapy may be
possible, where a person's own stem cells could be modified to
carry the correct gene to the liver and repopulate it, Di
Bisceglie said.
For people with hepatitis or who have liver damage from
drugs or alcohol, it may be possible some day to repopulate
their livers with healthy cells derived from their own stem
cells.
This technique would differ from a regular liver transplant
from a donor, which carries the risk that the body would
reject the organ.
The American Liver Foundation and the Mary Lea Johnson
Richards Research Foundation paid for the study.
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