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Type 1 Diabetes May
be
REVERSED with OWN STEM CELLS
- 4th March, 2010
Yes ..there is hope for Diabetes. Researchers have used
injections of patients' own stem cells to reverse the course of
type 1 diabetes, reports a research team from the University of
São Paulo in Brazil and Northwestern University in Chicago.
The findings, published in the current issue of the Journal of
the American Medical Association, exemplify the remarkable
gains made by researchers, who are battling a continuously
spreading disease that now affects nearly 8% of adults and
children. (See the top 10 medical breakthroughs of 2008.)
The research team, led by Dr. Julio Voltarelli of the
University of Sao Paulo, is the first to successfully treat
type 1 diabetes patients with their own stem cells. The group
first reported its initial achievement in 2007, with 15 type 1
diabetes patients who received their own stem cells and no
longer needed insulin to control their blood sugar levels.
In the new study, a follow-up of their previous work,
Voltarelli and his colleagues detailed the same success with an
additional eight patients, and also confirmed that in the
majority of them, the stem cell transplant led to an
appreciable repopulation of functioning insulin-producing beta
cells in the pancreas.
"I wouldn't use the word cure," says Dr. Richard Burt, one of
the co-authors from Northwestern University. "But it appears we
changed the natural history of diabetes. It's the first therapy
for patients that leaves them treatment-free - no insulin, no
immune suppression for almost five years."
The idea behind the transplant is simple. In type I diabetes,
the patient's own immune system turns on the beta cells that
produce insulin, the hormone that breaks down the glucose we
eat in food. Eventually, the immune cells will virtually
eliminate all of the body's beta cells, and glucose levels will
start to climb. Researchers believe that the trigger for this
attack lies somewhere within the immune cells, so one possible
treatment for the disease may be to wipe out the entire
existing immune system and replace it with a fresh one, derived
from stem cells without this destructive trait. (See pictures
from an X-Ray studio.)
That's the strategy that Voltarelli's team tested. First, they
carefully extracted a population of immune stem cells from the
bone marrow of each diabetes patient. Then each person was
treated with radiation, similar to the regimen that cancer
patients receive, in order to destroy the immune system.
Afterward, each patient received his own stem cells back by
injection. The scientists traced blood levels of a protein,
C-peptide, that beta cells produce, in order to confirm that
whatever remaining beta cells the patient had were now able to
grow again and repopulate the pancreas - and produce insulin.
Sure enough, levels of C-peptide rose in 20 of the 23 patients;
12 were able to stay off insulin therapy for three years, and
eight needed only intermittent help from insulin treatments
during the five-year study period. On average, the patients
remained free of insulin injections for 31 months.
That's a milestone in diabetes treatment. Type I diabetes
patients are locked in a constant struggle to maintain their
body's insulin levels. Since their beta cells no longer produce
the hormone on their own, patients must supply it themselves
with multiple injections throughout the day and night, or using
an insulin pump that dispenses insulin automatically through a
permanent tube under the skin. Voltarelli's stem cell strategy
provides a life-changing alternative that would take the burden
off the patient and put it back where it belongs, on the beta
cells.
That's the theory. But some experts point out that, in
practice, stem cell transplants are not always a home run. For
one, transplantation is a grueling and toxic process in which a
portion of the body's tissues - the immune system - is
destroyed with dangerous radiation. Then, there is the question
of timing. In most cases, patients with type 1 diabetes do not
show symptoms of their disease - such as high blood sugar
levels - until they have depleted their beta cell population
considerably.
Dr. David Nathan, director of the diabetes center at
Massachusetts General Hospital, notes that at this point, there
may not be enough beta cells remaining to seed a new population
of insulin-growing cells, even with an infusion of stem cells
to give them a more hospitable environment. "This study shows
that it can work, but how long it will work is a question," he
says. Previous studies have shown that after an immune cell
transplant, beta cells vigorously produce insulin for about six
months, and then start to die off, victims of the same immune
attack that destroyed their predecessors.
Voltarelli's team, however, has managed to show that the stem
cells can give long-lasting beta cells a chance to grow - at
least ones that can produce insulin for about three years.
Other researchers are pursuing intriguing new stem cell
options, including stem cells that can be grown from a
patient's own skin, which would eliminate the need for
extracting immune stem cells from bone marrow.
"Every door that we open leads to another door," says Burt.
"All research is built by sitting on the shoulders of other
studies. This trial is something that will contribute to and
move the field of stem cell therapy forward." It is, as Burt
says, a start.
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