Reduced Blood Leukocyte and Neutrophil Numbers in the Pathogenesis of Type 1 Diabetes

Very little is known about the role of the innate immune system in the course of human type 1 diabetes. Here we investigated neutrophil numbers along with other leukocyte populations in patients at diagnosis of type 1 diabetes and during prediabetes. Complete and differential blood counts were analyzed from 107 adult patients with newly diagnosed type 1 diabetes, 21 children with persistent islet autoantibodies and a family history of type 1 diabetes, and 1 238 age and gender matched control subjects, all individuals without any signs of acute infection. Adult patients with newly diagnosed type 1 diabetes had significantly lower total WBC (p < 1 x 10(-6)), neutrophil (p < 1 x 10(-6)), basophil (p < 1 x 10(-6)), monocyte (p = 4 x 10(-6)) and lymphocyte (p < 1 x 10(-6)) counts compared to control subjects. Erythrocyte, eosinophil and platelet counts did not differ between groups. Similarly, children with persistent islet autoantibodies had decreased WBC (p = 0.001), neutrophils (p = 0.003), and lymphocytes (p = 0.006) in comparison to control children. Our findings demonstrate a perturbation of leukocyte homeostasis at and prior to onset of type 1 diabetes suggesting a general involvement of the innate immune system in the pathogenesis of type 1 diabetes.