A new treatment has cured type 1 diabetes in mice by stopping their own killer immune systems from turning on themselves and allowing the insulin- producing cells of the pancreas to regenerate. The research promises to yield improved therapies for people afflicted by this and other autoimmune diseases including rheumatoid arthritis, Crohn's disease, and lupus.

"This is the first time anyone has ever been able to reverse established diabetes and literally regrow the affected organ," said Denise Faustman, M.D., Ph.D., of Harvard Medical School, lead investigator of the study and chair of the board of directors of the Society for Women's Health Research. "This same therapy may be feasible in humans."

The ABCs of Autoimmunity
The immune system normally springs to action when bacteria, viruses and other unfamiliar cells invade the body. Yet in autoimmune diseases the body attacks its own healthy tissue. For unexplained reasons, women's immune systems are more likely than men's to turn on themselves. In fact approximately 75 percent of autoimmune disease sufferers are women.

In type 1 diabetes, the immune system attacks and destroys the pancreas, leaving the body without ample insulin to control the level of blood sugar. Uncontrolled diabetes wreaks havoc on blood vessels and organs leaving sufferers at increased risk for heart disease, amputations, and blindness. Type 1 diabetes usually sets in during puberty and affects more than 500,000 Americans.

New Treatment Reverses Type 1 Diabetes
Dr. Faustman and colleagues used a two-pronged approach to halt the body's attack on itself. First they used a naturally occurring chemical, TNF-alpha, to kill misdirected immune cells programmed to attack the pancreas. Then, they trained immature immune cells to correctly distinguish between self and non-self thus preventing future attacks.

Approximately 75 percent of diabetic mice that received this treatment were effectively cured of diabetes long after the therapy was discontinued. After more than three months, the researchers killed the animals to examine their pancreases. Autopsies revealed "beautiful, functional" pancreatic cells in place of a defunct organ.

Dr. Faustman theorizes that killing off awry immune cells and thus providing a nurturing environment for damaged organs to regrow may similarly eliminate many other autoimmune diseases. She emphasizes, however, that researchers are a long way off from determining whether the laboratory findings can translate into new treatments for humans. The study was funded by a grant from the Iacocca Foundation.