The antibody is a kind of protein that helps to fight with foreign objects that come in touch with your body. Those antibodies include virus or bacteria that is harmful to the body.
In some cases, the immune system produces autoantibodies which are also antibodies but it happens to attack the normal cells of the body. It leads to the autoimmune disorder.
Hence, Type 1 diabetes is identified as a condition where there is lack of insulin in the body as a result of the autoimmune process. It is responsible for destroying beta cells in the pancreas which produces insulin for the body.