Stem Cells May Stop Type 1 Diabetes
Blood Stem Cell Transplant Leaves Diabetes Patients Insulin Free -- So Far
April 10, 2007 -- After transplants of their own blood stem cells, 14 of 15
type 1 diabetes patients are insulin free for one to 36 months -- and
In type 1 diabetes, the body can't make the insulin it needs, and so insulin
injections are necessary for treatment. After their transplants, most of the
patients in the study became free from insulin injections.
It's the first time the treatment has been used in type 1 diabetes, although
it's helped patients with other autoimmune diseases. The early success is
encouraging -- but nobody is using the word "cure."
It's not yet clear exactly how the stem cell treatment works, or even
whether it truly works at all. And it's far from clear how long treated
patients will remain insulin free.
"Very encouraging results were obtained in a small number of patients
with early onset disease," conclude researchers Júlio C. Voltarelli, MD,
PhD, of the University of São Paulo, Brazil, and colleagues.
The researchers warn that longer follow-up of trial patients, further
biological studies, and, finally, a clinical trial will be needed to confirm
that the treatment works. Their report appears in the April 11 issue of
TheJournal of the American Medical Association.
Early Results, Enormous Promise
In type 1 diabetes, haywire immune cells attack the insulin-making beta
cells in the pancreas. This means people with type 1 diabetes can't make the
insulin they need and require the use of supplemental insulin. The goal of the
treatment is to get rid of these bad immune cells and to replace them with
immature cells that have not yet learned bad habits -- thus stopping beta-cell
damage and restoring proper immune function.
The treatment is called autologous nonmyeloablative hematopoietic stem cell
transplantation. It's a four-step process:
- Soon after diagnosis of type 1 diabetes -- while a person still has plenty
of beta cells left -- the patient is given drugs that stimulate production of
blood stem cells.
- The blood stem cells are removed from the patient's body and frozen for
- The patient is given drugs and antibodies that kill off immune cells,
leaving other blood cells intact.
- The blood stem cells are reinfused into the patient.
The treatment didn't work in the first patient, probably because he had too
few beta cells when he started.
But the next 14 carefully selected patients did much better. All were
treated soon after diagnosis of type 1 diabetes. All eventually stopped needing
insulin -- for one to 35 months.
In an editorial accompanying the study, University of Miami diabetes
researcher Jay S. Skyler, MD, warns against "false hope based on the
preliminary nature of the study results."
Skyler warns that much work remains to be done:
- The study did not include a control group. This makes it impossible to know
what would have happened if similar patients had received no treatment -- an
important factor, given that soon after diagnosis, many type 1 diabetes
patients enter a "honeymoon" period of remission.
- It's simply too soon to know how well the treatment worked, or whether
patients eventually will do better than untreated patients.
- It's not at all clear whether the treatment works because it stops beta
cell destruction or whether it allows beta cells to regenerate.