UF researchers screen relatives in hunt for type 1 diabetes risk factors

The key to curing type 1 diabetes is likely to be a family affair, say University of Florida experts involved in an international research effort to probe the biologic basis for the disease’s development.

Researchers participating in the consortium known as Type 1 Diabetes TrialNet will screen relatives of patients with diabetes for markers in the blood that appear years before diabetes develops. The project aims to evaluate tens of thousands of people, tracking them over the years to see who acquires the disease and which factors play a role in causing the immune system to destroy insulin-producing beta cells in the pancreas.

“Over the past 20 years, we’ve learned that type 1 diabetes is an immune-mediated disease occurring in genetically at-risk subjects,” said Desmond Schatz, M.D., a professor and associate chairman of the department of pediatrics and the study’s principal investigator at UF. “The disease can be predicted both in higher-risk relatives — one in 20 will develop it — and the low-risk general population — one in 300 will develop it. In TrialNet, we intend to study the precise mechanisms leading to the disease and institute therapies aimed at preventing and ameliorating the disease.”

Type 1 diabetes, formerly known as juvenile-onset diabetes, is a lifelong disease that accounts for 5 percent to 10 percent of all diagnosed cases of diabetes in the United States. Insulin is needed to convert blood glucose (sugar) into energy; without adequate insulin, the sugar in the blood isn’t used and builds up. People with type 1 diabetes need daily insulin injections or an insulin pump to control blood sugar. Insulin replacement is not a cure for type 1 diabetes, it is only a means of controlling the disease.

UF is one of 18 medical centers in the United States, Canada, Europe and Australia participating in Type 1 Diabetes TrialNet. This network of researchers, labs and facilities is dedicated to understanding the autoimmune process that leads to type 1 diabetes, preventing the disease and stopping its progression in those who have been newly diagnosed. At diagnosis, most people still have some of their insulin-producing beta cells. In time, however, the immune system destroys more of these cells, making it harder to control blood sugar levels.

To be eligible for the TrialNet Natural History Study, one must be between 1 and 45 years of age and have a first-degree relative (a mother, father, brother, sister) with type 1 diabetes, or between 1 and 20 years of age with a second-degree relative (aunt, uncle, niece, nephew, cousin, grandparent) with type 1 diabetes. For research purposes, type 1 diabetes is defined as having developed before a person is 40 years of age and requiring insulin treatment within one year of diagnosis.

The screening, available at no cost to study participants, involves a simple blood test for the autoantibodies that appear in at-risk people years before diabetes develops. After enrolling in the study, participants will be closely monitored for signs of type 1 diabetes and may be offered the opportunity to participate in studies that attempt to stop the disease process.

A second TrialNet study will seek to delay or stop the immune destruction of beta cells, building on scientific knowledge gained from earlier research on drugs that treat other autoimmune diseases and prevent rejection of transplanted organs.

Researchers at UF and five other medical centers will study patients ages 12 to 35 who received a diagnosis of type 1 diabetes within the previous three months. They will be randomly assigned to receive one of two drugs currently approved by the Food and Drug Administration for preventing organ rejection.

Type 1 Diabetes TrialNet is funded by the National Institutes of Health, part of the U.S. Department of Health and Human Services. The Juvenile Diabetes Research Foundation International and the American Diabetes Association also support TrialNet research. UF received a seven-year grant totaling $2 million for the various TrialNet studies, which began in September 2001. More information can be found at www.DiabetesTrialnet.org.