WEDNESDAY, Oct. 8, 2008 (HealthDay News) -- Swedish researchers have developed a vaccine that may change the way the immune system responds in people who are newly diagnosed with type 1 diabetes.
"By a very simple vaccination, without adverse events, it seems possible to save [a person's] own insulin secretion, which may be extremely important for diabetic children and adolescents," said the study's lead author, Dr. Johnny Ludvigsson, a professor of pediatrics and head physician at Linkoping University Hospital.
However, the results of this preliminary study didn't change the clinical course of the disease for the study participants. Insulin requirements of children involved in the study were similar whether the children were treated with the new vaccine or received a placebo.
Results of the study were released Wednesday online by the New England Journal of Medicine, and will be published in its Oct. 30 issue.
Type 1 diabetes is believed to be an autoimmune disease in which the body's immune system mistakenly attacks itself. In type 1 diabetes, "insulin-producing cells are killed by their own immune system in a 'civil war,' " said Ludvigsson. This civil war leads to a lack of insulin in the body, and insulin is a key hormone that allows the body to metabolize carbohydrates and sugar from foods. Without replacement insulin, people with type 1 diabetes would die. Even with treatment, there are numerous complications that can occur, including damage to the kidneys, eyes, heart and nerves.
Past research on interrupting an immune system gone awry has focused on drugs that suppress the immune system, like those used for people receiving transplants or being treated for cancer. Although researchers did have some success in slowing or stopping early-onset diabetes, that success came at a cost.
"Many drugs caused severe toxic side effects," said Dr. Denise Faustman, director of immunobiology at Massachusetts General Hospital in Boston, and the author of an accompanying editorial in the journal. "With a big immune suppressant, you can change the amount of insulin kids take, sometimes you can even make them insulin-free for awhile, but you may cause kidney damage. The ratio of toxicity versus benefit wasn't there."
The new vaccine treatment under study focuses on the immune response, rather than trying to blunt the entire immune system. It's made of a protein called GAD that's normally found in the brain and in the insulin-producing islet cells of the pancreas. In people with diabetes, it's as if they're allergic to GAD, Ludvigsson explained.
The hope is that the vaccine he and his team developed -- which was administered the first day of the study and then again at day 30 -- will work in a similar manner to allergy immunotherapy and help the body learn to tolerate GAD again.
The study included 70 children between the ages of 10 and 18 who had been diagnosed with type 1 diabetes no more than 18 months before the start of the study. The children were randomly split into two groups -- one received treatment, the other a placebo.
At the end of the study, insulin requirements didn't change. But, in children who were more recently diagnosed, there was evidence that the treated group retained more activity in their pancreas, Ludvigsson said.
That's important because the more insulin-producing function you retain, "the short-term risks are less, as are the risk of long-term complications," said Dr. Richard Insel, executive vice president of research for the Juvenile Diabetes Research Foundation.
"What you're seeing is, the field is trying to move away from broad-based immunosuppression to targeting one specific immune response, and this is an early attempt to develop a much more focused approach to modulate immune function in new-onset diabetes," Insel said.
The good news is that the vaccine seemed safe and didn't cause any troubling side effects, according to Faustman. "GAD looks pretty benign here -- two vaccinations given four weeks apart. There's something positive happening, though the therapeutic benefit is small. But, there was a measurable and significant benefit."
Ludvigsson said the researchers have begun new trials, including children who've had diabetes for a much shorter time because those were the ones who responded most in this study. Additionally, they'll be working on a clinical trial to see if this vaccination could be used to prevent type 1 diabetes from occurring in children who have a high risk of the disease.
More information
Learn more about type 1 diabetes from the U.S. National Library of Medicine.
