Role of autoantibodies in type 1 diabetes.

Type 1A, the immune mediated form of diabetes, is a relatively common disorder that develops in genetically susceptible individuals. The disease is associated with a series of anti-islet autoantibodies and the autoantibodies can be present for years prior to the onset of hyperglycemia. In general it is thought that type 1A diabetes is T cell mediated, but there is evidence from studies in the NOD mouse model that antibodies and B-lymphocytes contribute to pathogenesis. In man evidence is lacking that transplacental passage of anti-islet antibodies increases disease risk. Well characterized, high throughput autoantibody assays (tested in a series of international workshops) are now available, and are the mainstays of prediction of type 1A diabetes, diagnosis of the immune mediated form of diabetes, and are important for the design of trials for the prevention of type 1A diabetes. In addition to anti-islet autoantibodies, patients with type 1A diabetes develop a series of associated autoimmune disorders that are usually detected with screening for additional autoantibodies (e.g. anti-thyroid, anti-transglutaminase, anti-21 hydroxylase, anti-parietal cell). At present it is possible to predict the development of type 1A diabetes and prevent the disorder in animal models, but we lack proven therapies for disease prevention in man. The ability to detect specific anti-islet autoantibodies provides the foundation for developing and testing these preventive therapies.