Immune responses to insulin and lymphocyte subclasses at diagnosis of insulin-dependent diabetes and one year later.

Insulin induced proliferation of blood mononuclear cells, numbers of blood B and T cells, of blood lymphocytes bearing interleukin 2 receptors or HLA class II molecules were assayed at diagnosis and one year later in children with insulin-dependent diabetes mellitus (IDDM) and in healthy children. Insulin and islet cell antibodies were also studied. The numbers of lymphocytes expressing HLA class II molecules and NK cells were increased at diagnosis. T cells of the helper/inducer (CD4+) phenotype and interleukin 2 receptor positive lymphocytes were increased both at diagnosis and one year later. At diagnosis, insulin induced proliferation of blood mononuclear cells in 65% and one year later in 50% of the patients. Insulin antibodies were detected in 10% and islet cell antibodies in 90% of patients at diagnosis, and in 67% and 78%, respectively, one year later.