Stem Cell Therapy May Combat Type 1 Diabetes

Small trial offers hope, but much more research is needed, experts
say

http://www.nlm.nih.gov/medlineplus/news/fullstory_47733.html

Tuesday, April 10, 2007

TUESDAY, April 10 (HealthDay News) -- A pilot study of people newly
diagnosed with type 1 diabetes found that stem cell therapy
eliminated the need for insulin therapy for varying periods of time.
This is the first trial to look at stem cell therapy in humans with
this form of the disease. But experts stressed that the research is
preliminary and urged caution when interpreting the results, which
are published in the April 11 issue of the Journal of the American
Medical Association.

"This may be the first step in something that could be promising, but
I need to see a control group and longer follow-up before I'd go out
on a limb," said Dr. Jay S. Skyler, author of an accompanying
editorial in the journal and associate director of the Diabetes
Research Institute at the University of Miami Miller School of
Medicine. "But this is worthy of further experimentation."

Type 1 diabetes develops when the body's immune system attacks the
pancreatic beta cells, which produce insulin -- the hormone that
transports sugar from the blood to cells for energy.

"In type 1 diabetes, the immune system is out of balance," Skyler
explained. "Ordinarily, all of us have some cells with the potential
to destroy the pancreas, but the regulatory immune system prevents
those cells from becoming sufficiently active. In type 1 (diabetes),
there's a greater proportion of activity of the destroying cells and
lesser activity of the regulatory cells. The goal is to try to bring
that back into balance."

By the time a person is diagnosed with the disease, some 60 percent
to 80 percent of the beta cells have already been destroyed. And
people who have more functioning beta cells tend to have fewer
complications down the line, research has shown.

Immunosuppression therapy, designed to dampen the immune system, can
help, but these patients still need to take insulin to regulate their
blood sugar. Meanwhile, stem cell therapy has had some success with
other autoimmune diseases, such as lupus, but not with type 1
diabetes.

"There has been use of this specific procedure in other autoimmune
disease in human beings with some suggestion of promise of effect,
and it's been advocated for a number of years that this kind of
approach might be useful in type 1 diabetes," Skyler said.

The new study, conducted by scientists in Sao Paolo, Brazil, and in
Chicago, involved 15 patients newly diagnosed with type 1 diabetes.
All participants underwent high-dose immunosuppression therapy
followed by a procedure called autologous nonmyeloablative
hematopoietic stem cell transplantation (AHST) to preserve beta-cell
function.

AHST involves removing a patient's own blood stem cells, treating
them, and then returning them to the patient.

"Using bone marrow precursor cells, which are precursors of immune T-
cells, is designed to reset the immune system," Skyler said. "The
reason for choosing a point early in time is that you want to have
enough beta cells that are still left."

During follow-up that lasted up to 36 months, 93 percent of the
patients achieved some length of insulin independence. Fourteen
patients became insulin free -- one for 35 months, four for at least
21 months, seven for at least six months. Two more participants who
had late responses to the stem cell therapy became insulin free for
one and five months, respectively.

One person developed pneumonia, and two others developed problems
with their endocrine system, which governs hormones in the body.
It's unclear exactly how the stem cell transplants worked their
magic. And there are still numerous questions.

"The obvious question is how long does it work and what is the risk
of treatment," said Dr. Larry Deeb, president of medicine and science
at the American Diabetes Association. "But the excitement is where we
are in diabetes research and treatment, and the excitement some of
these questions generate for people who have diabetes and for the
diabetes community and for the profound argument that this is not a
time to be proposing less money for research in diabetes."