Immune System

Type 1 diabetes is the result of the immune system attacking and destroying beta cells in the pancreas. This is called an autoimmune response by the body. Symptoms of diabetes appear long after this process begins. In fact, type 1 diabetes is often not diagnosed until most beta cells have already been destroyed.

Although this autoimmune response can be triggered by a viral infection, recent research suggests insulin itself can be a key trigger of the immune attack on beta cells. People who are genetically predisposed to developing type 1 diabetes may have an autoimmune response to insulin as if it were a foreign substance, or antigen. Normally, the body makes proteins called antibodies to fight antigens. But in people with type 1 diabetes, antibodies to insulin and other proteins produced by beta cells have been discovered.