The soluble receptor of interleukin 2 is not a serum marker of the autoimmune activity in type I diabetes mellitus.

In order to determine if soluble interleukin 2 receptor (IL2R) was useful as a marker in screening for early Type 1 diabetes and in monitoring immunological treatment, we assayed serum IL2R levels in 67 controls, 43 patients with newly diagnosed diabetes and 28 first degree relatives of diabetic patients (5 subjects were islet cell antibody positive). In 23 diabetes, specimens were analysed at 3 and 6 months after diagnosis whether or not cyclosporin A was administered. Seven patients were in a clinical trial using anti IL2R monoclonal antibody and cyclosporin A. Since IL2R level in the normal population is elevated in the first 5 years of life then decreases until adulthood (age:IL2R correlation between 0 and 15 years: r = -0.42, P less than 0.05), subjects were carefully matched in age. In recent onset diabetes, this negative correlation disappeared and IL2R levels tended to decrease particularly in younger subjects. In Type 1 prediabetic subjects presenting persistent islet-cell antibody serum IL2R was not elevated. During immunological treatment of recent onset diabetes, serum IL2R remained stable and was not modified by cyclosporin A. As expected IL2R became undetectable during treatment with anti IL2R MC Ab. But it rebounded when treatment was stopped with no effect on remission. We concluded that IL2R levels in Type 1 diabetic patients is not useful in screening autoimmune activity or in evaluating the effectiveness of immunosuppressors.