Study attempts to reverse autoimmunity in type 1 diabetes

Over 1 million people in the United States have Type 1 diabetes and the incidence is growing. In this disease, the body's immune system attacks and destroys the insulin-producing cells in the pancreas, called beta cells. However, at the time of diagnosis with Type 1 diabetes, a small number of beta cells may remain active in many individuals. Since even small amounts of natural insulin production can decrease the long-term effects of diabetes, therapies that attempt to rescue these remaining cells are badly needed.

In the clinical research trial, the combination of the two drugs Proleukin (IL-2) and Rapamune (sirolimus) were administered to see whether the drugs would affect the immune system to halt the autoimmune destruction of the remaining beta cells. The authors of the study describe successful boosting of regulatory components of the immune system in all nine subjects treated in the trial. However, other elements of the immune system also were expanded that were not anticipated. The temporary impairment of beta cell function led the authors to conclude that this drug combination was not having the desired overall effect. Monitoring of the insulin production in the nine subjects indicated that the beta cell preservation goal was not achieved, and the study was therefore stopped. "This study result has been extremely important to scientists looking for ways to stop the immune attack," says Dr. Greenbaum. "Our aim would be to harness the good effects of this therapy while preventing the bad effects." Participants who haven't yet completed the study will continue to be followed.

"The clinical and mechanistic findings from this study can help guide future treatments that boost good immunity," says Gerald Nepom, MD, PhD, Director of ITN. "This was an important clinical trial that will improve the design of subsequent trials to rescue beta cells in Type 1 diabetes."