Insulin-dependent Diabetes and beta cells

IDDM is an autoimmune disease in which the body attacks and ultimately destroys the beta-cells. While the classic symptoms-- hyperglycemia and ketosis--can develop rapidly, the disease itself is a chronic process that may be present for years. Symptoms occur late in the course of the disease, after most of the beta-cells have been destroyed. Autoantibodies against islet-cell components or insulin have been found in at-risk patients years before clinical diabetes developed. In a comprehensive review of IDDM, Atkinson and Maclaren wrote that the autoimmune attack is probably triggered by a virus whose proteins share an amino acid sequence with a beta-cell protein. One candidate is Coxsackie virus, which causes a systemic infection. It is also possible that a virus may infect beta-cells directly, causing cell death and sensitization of the immune system to beta-cell components. It was suggested recently that drinking cow's milk in early life may initiate beta-cell destruction through molecular mimicry, but subsequent studies have not turned up much supporting evidence.
source:Atkinson MA, Maclaren NK. N Engl J Med.