Two years ago, Dr. Burt and colleagues showed that 14 of 15 patients (who were also included in the new study) treated this way were able to go without insulin injections for one to 35 months, but it wasn’t clear if this was due to closer medical follow-up and lifestyle changes. In the new study, the researchers measured a protein that suggested the patients did indeed have insulin-producing beta cells, which are typically destroyed by the autoimmune disease.
So far, stem cell transplantation is the only therapy shown to reverse type 1 diabetes in humans, the research team noted.
However, Mohamed El-Shahawy, MD, a transplant nephrologist and a member of the islet cell transplantation team at City of Hope in Duarte, Calif., cited a number of concerns around the study and risks to patients.
“This study basically subjects patients to an unproven, high-risk procedure,” he said. “Could it be a breakthrough? I don’t see it.”
The procedure can be risky. After harvesting stem cells from blood samples, the patient is given chemotherapy to suppress the immune system. Then the stem cells are returned to the patient through intravenous injection.
Transplanting a person’s own stem cells (which are made by bone marrow and can be found in blood) may “reset” the body’s immune system. This may allow the insulin-producing beta cells in the pancreas to either mend themselves or regenerate.
The greatest risk is that a patient will die of an infection, Dr. Burt says. While there were no deaths in the study, two patients developed pneumonia and three patients had problems with endocrine function and nine developed sperm deficiency.
In a related editorial, Christopher D. Saudek, MD, of Johns Hopkins University School of Medicine in Baltimore, notes that there isn’t likely to be a cure for type 1 or type 2 diabetes any time soon. For now, he said, patients need to use all the therapies that are currently available.
“A great deal of the morbidity and reduced quality of life among patients with diabetes, as well as substantial societal expense, could be avoided or reduced by taking full advantage of therapies available today,” he wrote.
The Juvenile Diabetes Research Foundation also cited a number of issues that need to be addressed before such a procedure would become available to patients. While not involved in the study, the foundation says “it does provide some intriguing results that bear further investigation.”