People with Type 1 diabetes who received stem cell transplants from their own cells were able to go as long as four years without needing insulin treatments, U.S. researchers reported.
They said the process, which involves injecting people with stem cells made from their bone marrow cells, appears to have a lasting effect.
The study involved patients with Type 1 diabetes, formerly called juvenile diabetes, which occurs when the immune system goes haywire and starts attacking itself, destroying insulin-producing cells in the pancreas needed to control blood sugar.
These patients typically need daily insulin therapy to control their diabetes.
Dr. Richard Burt of Northwestern University’s Feinberg School of Medicine in Chicago and colleagues first reported on the short-term success of the procedure, known as autologous non-myeloablative hematopoietic stem-cell transplantation, in 2007 but have since looked at how long it persisted.
Writing in this week’s Journal of the American Medical Association they said 20 of 23 patients “became insulin free — 12 continuously and eight transiently — for periods as long as four years.” The transient group of eight had to restart insulin at reduced levels.
The patients ranged in age from 13 to 31.
To find out if the change was lasting, the research team said they measured levels of C-peptides, which show how well the body is producing insulin. They found those levels increased “up to 24 months after transplantation and were maintained until at least 36 months,” their report said.
Even in the group which had to restart insulin there was still a significant increase in C-peptide levels that lasted at least two years, the researchers said.
They said the procedure was able to induce “prolonged and significant increases of C-peptide levels” in the small group of patients who were taking little or no insulin.
“At the present time (it) remains the only treatment capable of reversing Type 1 diabetes mellitus in humans,” the team wrote.
“Randomized controlled trials and further biological studies are necessary to confirm the role of this treatment in changing the natural history of (the disease),” they added.
“After a mean follow-up of 29.8 months following autologous nonmyeloablative HSCT in patients with newly diagnosed Type 1 DM, C-peptide levels increased significantly and the majority of patients achieved insulin independence with good glycemic control,” the study authors write.
During follow-up, 20 patients without previous ketoacidosis and who were not receiving corticosteroids during the preparative regimen became insulin-free. Of these 20 patients, 12 remained insulin-free for a mean duration of 31 months (range, 14 – 52 months), whereas 8 patients relapsed and again required insulin use at low doses of 0.1 to 0.3 U/kg.
In the group that continued to require insulin, HbA1c levels were less than 7.0%. Mean area under the curve (AUC) of C-peptide levels increased from 225.0 ± 75.2 ng/mL per 2 hours before transplantation to 785.4 ± 90.3 ng/mL per 2 hours at 24 months after transplantation (P < .001) and to 728.1 ± 144.4 ng/mL per 2 hours at 36 months after transplantation (P = .001).
In the group that was transiently insulin-free, mean AUC of C-peptide levels also increased from 148.9 ± 75.2 ng/mL per 2 hours before transplantation to 546.8 ± 96.9 ng/mL per 2 hours at 36 months after transplantation (P = .001), with this increase sustained at 48 months. Two patients in this group regained insulin independence after being treated with sitagliptin, and C-peptide levels concomitantly increased.
Adverse effects were bilateral nosocomial pneumonia in 2 patients, late endocrine dysfunction in 3 patients, and oligospermia in 9 patients. There were no deaths.
Limitations of this study include small sample size and lack of a control group.
“At the present time, autologous nonmyeloablative HSCT remains the only treatment capable of reversing Type 1 DM in humans,” the study authors write. “Randomized controlled trials and further biological studies are necessary to confirm the role of this treatment in changing the natural history of Type 1 DM.”
JAMA. April 15, 2009;301:1573–1579.