Insulin responses and lymphocyte subclasses in children with newly diagnosed insulin-dependent diabetes

Children with newly diagnosed insulin-dependent diabetes mellitus (IDDM) had increased numbers of CD25 positive lymphocytes in peripheral blood and peripheral blood mononuclear cells responded to insulin antigens by proliferation. The CD25 positivity and insulin proliferation were associated to the duration of symptoms before the diagnosis of IDDM. Thus increased numbers of CD25 positive cells were found in 89% and insulin induced proliferation in 100% of patients with symptoms of diabetes of less than 1 week's duration before diagnosis, while CD25 positivity and insulin-induced proliferation were observed in 36% and 29% of children who had had symptoms for 4 weeks or more before diagnosis. Children with IDDM also had increased numbers of CD4 positive T cells in peripheral blood. The frequency of HLA-DR4 and HLA-DR3/4 in diabetic children was higher and that of HLA-DR2 lower than in the normal population. Insulin, islet cell, gastric-parietal cell, thyroid and antinuclear antibodies did not correlate to the duration of symptoms before diagnosis.