Immunological aspects of diabetes

Notable progress was achieved by the investigations on the immunology of diabetes. Studies of immunogenetics have demonstrated that Type 1 (insulin-dependent) diabetes shows a primary association with the HLA class II genes (e.g., with HLA-DR3 and DR4 in Caucasoid populations), a determining features of this type of the disease. Besides, it presents a wide variety of autoantibodies, such as islet-cell cytoplasmic antibodies (ICA), islet-cell surface antibodies (ICSA), complement-fixing islet-cell antibodies (CF-ICA), antibodies to a Mr-64000 islet-cell protein, and many studies are trying to evaluate their pathogenic and predictive role. Various changes of cell-mediated immunity have been also described. The proportion of activated T cells in circulation is increased in patients with Type 1 diabetes. It was assumed that the T cells are the main cause of pancreatic beta-cell damage. Type 1 diabetes is actually considered as a chronic autoimmune disease, with several stages of evolution leading to the destruction of the pancreatic beta-cells, with a consecutive gradual decrease of insulin secretion. From the therapeutic point of view, many problems are raised by insulin immunogenicity, mainly depending on the so-called "contaminants". To avoid phenomena of allergic reactions, immunological insulin-resistance, lipodistrophy, a.o., highly purified and human type insulins have been prepared. The insulin autoantibodies (IAA) detected before the clinical onset of Type 1 diabetes are considered a new marker of autoimmunity. New hopeful prospects are opened by diabetes immunotherapy, in which Cyclosporin A detains a particular role, although it should be used only in special conditions, under strict clinical observation.(ABSTRACT TRUNCATED AT 250 WORDS)