The immunology of the insulin receptor

We have detected and characterized anti-insulin-receptor autoantibodies which circulate in several patients with insulin resistance diabetes. These antibodies are predominantly IgG and are polyclonal. They inhibit insulin binding to its receptor on a variety of tissues from widely separated species. Antibodies obtained from different patients appear to bind to different determinants on the receptor and alter receptor function in several ways. Some anti-receptor antibodies are capable of stimulating insulin-like effects on target tissues, while others block insulin-stimulated effects. Direct labeling of anti-receptor antibody with 125I permits use of these antibodies as an assay and probe of insulin receptors.