TUESDAY, March 30, 2004 (HealthDayNews) -- Scientists are zeroing in on proteins that contribute to the destruction of insulin-producing cells in type 1 diabetes.
Their work may lead to medications that can prevent or, in some cases, even reverse type 1 diabetes in its early stages.
To that end, researchers presented findings from two promising new studies this week. One study was presented March 29 at the International Diabetes Society Meeting in Cambridge, England, while the second was delivered March 30 at the American Chemical Society's annual meeting in Anaheim, Calif.
"We still don't know how diabetes occurs," says Dr. Stuart Weiss, an endocrinologist at New York University Medical Center. "But we're beginning to unravel the mystery," he says, adding the findings from both of these studies are exciting.
Diabetes affects more than 18 million Americans, according to the American Diabetes Association. There are two types of diabetes, type 1 and type 2. Both studies concentrated on type 1 diabetes, once known as juvenile-onset diabetes, which is an autoimmune disease. The immune system perceives normal insulin-producing cells in the pancreas as foreign invaders and mistakenly attacks and destroys these cells. The complete destruction of these cells takes time, but once all are destroyed, the body can no longer produce insulin, and people with this form of the disease must take daily insulin injections.
Weiss says the therapeutic compounds in both studies are designed to stop that process before it begins, or possibly reverse it before the complete destruction of the insulin-producing cells has occurred. He explains that these compounds aren't actually vaccines because they dampen the immune response rather than stimulate it, as most vaccines do.
The first study was a clinical trial of a drug called Diamyd, which helps the body tolerate the "GAD" protein. GAD is found in both the brain and the pancreas. In type 1 diabetes, it appears the immune system attacks the GAD protein in the pancreas. A test has been developed by UCLA researchers to identify antibodies to GAD in the blood, which can help identify who is at risk for developing diabetes. Weiss says not everyone with type 1 diabetes tests positive for GAD antibodies, but a majority do.
In the study, Swedish researchers split 47 volunteers, recently diagnosed with type 1 diabetes, into four groups. All received at least one injection of the drug, ranging from 4 to 500 micrograms, and a booster shot four weeks later. Three people in each group received a placebo injection. According to the researchers, the drug helped people maintain their insulin-producing ability when compared to placebo, and there were no side effects reported.
In the second study, researchers from the North Shore-Long Island Jewish Research Institute report they have found a compound that can block the process that causes diabetes -- at least in mice, anyway.
Study author Yousef Al-Abed says this compound, which is called ISO-1, targets a different protein -- MIF -- that is also believed to play a role in the development of diabetes.
When ISO-1 was given to mice that were also given a chemical that induces diabetes, none developed the disease. Control mice who didn't receive ISO-1 did develop the disease. Another set of mice were genetically engineered to develop diabetes, but ISO-1 prevented the disease in 90 percent of them.
Al-Abed says one of the advantages of ISO-1 is that it will likely be possible to put it into an oral form. He says that the drug could then easily be given to children who were identified as high-risk for developing diabetes, and would hopefully prevent the disease.
"This just is the beginning of a long commitment," says Al-Abed, an associate investigator at North Shore-Long Island. "But where we're heading is protecting against the onset of the disease."