Stem Cells Promising for Type 1 Diabetes
Insulin No Longer Needed by Some Diabetic Patients Who Underwent Experimental Treatment
April 14, 2009 -- More than half of the newly diagnosed patients with type 1 diabetes who got an experimental treatment for the disease did not need insulin injections for at least a year.
Patients also showed improvements in the functioning of the insulin-producing cells that are attacked and destroyed in patients with type 1 diabetes.
Four of the 23 patients who took part in the study remained insulin free for at least three years and one patient went without insulin injections for more than four years.
The patients were the first to receive the novel stem cell transplant therapy to treat their type 1 diabetes.
After receiving transplants of their own blood stem cells, about half of the patients in the study became insulin free for an average of two and a half years.
But the treatment, which included the use of highly toxic immune-system suppressing drugs, was not without troubling side effects.
Two patients developed pneumonia while hospitalized for immunosuppression therapy, and nine developed low sperm counts as a result of exposure to one toxic drug. The latest results from the study appear in the April 15 issue of the Journal of the American Medical Association.
Diabetes specialist David M. Nathan, MD, who was not involved with the study, tells WebMD that the stem cell treatment is promising, but he adds that the side effects remain troubling.
“This is a pretty bold intervention that can involve serious complications,” he says. “The hope is that this will lead to more benign treatments that can keep people off insulin.”
Stem Cells for Diabetes
All the patients included in the stem cell study had been diagnosed with type 1 diabetes within six weeks of treatment, and all were producing some insulin on their own, although this production was greatly diminished.
Type 1 diabetes is an autoimmune disease in which the immune system attacks and destroys the insulin-producing cells within the pancreas.
The goal of the treatment was to kill the immune cells that were killing the insulin-producing cells and replace them with immature cells not programmed to disrupt insulin production.
The treatment, called autologous nonmyeloablative hematopoietic stem cell transplantation (HSCT), involved several steps.
Soon after diagnosis, the patients were given drugs to stimulate production of blood stem cells. The blood stem cells were then removed from the body and frozen.
Patients were hospitalized and given the toxic drugs that killed their circulating immune cells, and then the harvested blood stem cells were put back into the patient.
The first patient to receive the treatment did not improve, probably because he had too few functioning insulin-producing cells left.
But 20 of the next 22 patients treated with the experimental therapy were able to do without insulin injections or greatly reduce their insulin use for a few months to several years.