Cause of the autoimmune disorder in Diabetes Type 1

Prior to the diagnosis period, it is speculated that the regulatory T cells are unable to control cytotoxic T cells directed against self proteins.

CD4 and CD8 T cells coordinate to attack and destroy insulin-producing cells.

At the same time, B cells from the bone marrow are making antibodies against beta cell proteins. Thus, both T and B cells are engaged in the destruction process.

Though there may be some beta cell reformation that replaces destroyed cells, over the years there is a greater net destruction than replacement.

When the 80% of the beta cells are reduced the body is unable to secrete insulin.

Thus, blood sugar levels increase causing diabetes.