Tests on tissue from three of the patients with conventional type I diabetes
revealed the expected immune attack.
Meanwhile, type I diabetes
incidence in Puerto Rico is roughly 10 times the rate seen in Cuba, where breast-feeding is nearly universal.
Thus, the National Institute of Diabetes and Digestive and Kidney Diseases sponsored a trial of 1,441 people with Type I diabetes, which usually develops before age 30.
The new study focused on Type I diabetes patients, but many scientists think more rigorous glucose control may also benefit people with Type II diabetes, which generally strikes after age 40.
In recent years, researchers have gathered evidence implicating Type I diabetes as an autoimmune disorder, in which the immune system turns against the body.
The immune system in an individual with Type I diabetes may fail to recognize its own beta cells because they are deficient in the MHC class I proteins, which tag them as "self," Faustman says.
Louis and his co-workers report developing a potential treatment for Type I diabetes.
It doesn't diagnose Type I diabetes but picks out individuals who are likely to get the disease if they encounter a triggering factor.
Confirmation of the test's accuracy should enable physicians to determine whether children in families with a history of Type I diabetes have a high risk of the disease, says Charles M.
Researchers believe this amino acid, aspartic acid, protects against Type I diabetes by preventing immune cells from attaching to beta cells.