Stem Cell Transplant Resets Immune System in Type 1 Diabetes Patients

In the study, patients with Type 1 diabetes were treated with a high dose of immune suppression drugs followed by an intravenous injection of their own blood stem cells, which had previously been removed and treated.

“I think this treatment helped the body regenerate its immune system,” said Richard Burt, M.D., senior author of the study and associate professor of medicine at Northwestern's Feinberg School of Medicine, and chief of immunotherapy at Northwestern Memorial Hospital. The study was published in JAMA (Journal of the American Medical Association.)

Burt said this is the first time, to his knowledge, that patients with Type 1 diabetes have been treated with their own stem cells.

In Type 1 diabetes, the immune system attacks cells in the pancreas that make insulin. Insulin enables glucose to enter the body's cells to be used as fuel. Without adequate insulin, glucose builds up in the bloodstream instead of entering the cells.

People with Type 1 diabetes must inject themselves with insulin every day.  The disease can occur at any age, but usually starts in people younger than 30. Type 1 diabetes accounts for 5 to 10 percent of the 21 million diabetes cases in the U.S.

“Your immune system is your police force, “ Burt explained.  “It protects you from the environment. If it goes bad and attacks your body, you get an autoimmune disease that can destroy your organs or kill you.  It can't tell a good guy from a criminal. We take the whole department out and replace them with new recruits.  The body then stops attacking the islet cells in the pancreas that make insulin.”

“What we then believe happens is the body regenerates more islet cells,” Burt said. ”We believe this from many years of seeing patients get better from autoimmune disease.”

During a 7- to 36-month follow-up, 14 patients became insulin-free (1 for 35 months, 4 for at least 21 months, 7 for at least 6 months; and two with late response were insulin-free for 1 and 5 months, respectively.) Among those, one patient resumed insulin use one year after the therapy.  The only severe adverse effects were pneumonia in one patient and endocrine dysfunction in two others.

“In this trial we intervened early, within six weeks of onset of Type 1 diabetes,” Burt said.  “Whether we can successfully intervene later in the diagnosis is a big question that I'd like to look at in the future.“

Burt said further follow-up is necessary to confirm the duration of the insulin independence.  Randomized controlled trials and further biological studies also are necessary to confirm the role of the treatment in changing the natural history of Type 1 diabetes and to evaluate the contribution of adult stem cells to this change.

The study was conducted in Brazil under the direction of Julio C. Voltarelli, M.D., of the University of Sao Paulo, Ribeirao Preto, Brazil.