Convergence of genetic and environmental factors in the immunopathogenesis of type 1 diabetes mellitus

Environmental and immunological factors important in the pathogenesis of insulin-dependent type 1 diabetes (IDDM) are reviewed. Type 1 diabetes results from the selective autoimmune destruction of the pancreatic beta cells in genetically susceptible individuals. This autoimmune process is triggered by exposure to viruses, toxins, or dietary factors. This pre- clinical autoimmune stage of the IDDM results in both a cellular and humoral autoimmune response against pancreatic islet beta cell antigens. Individuals in this asymptomatic pre-diabetes phase can be identified by measurement of islet cell antibodies or detection of impairment of the first-phase insulin secretion. Recent studies suggest that by administering immunotherapy to individuals with pre-diabetes, it may be possible to prevent the onset of IDDM. Laboratory detection of individuals with pre-diabetes is a key step in developing strategies for the prevention of type 1 diabetes.