Brief CommunicationCompromised immune response in infants at risk for type 1 diabetes born by Caesarean Section

•Caesarean Section may reduce the immune status and responsiveness during childhood.•Infants born by Caesarean Section have lower serum concentrations of IFN-ɣ and IL-8.•Infants born by Caesarean Section have a weaker CD4+ T cell response to tetanus.

Children born by Caesarean Section have a higher risk for type 1 diabetes. We aimed to investigate whether Caesarean Section leads to alterations of the immune response in children with familial risk for type 1 diabetes. We examined measures of innate and adaptive immune responses in 94 prospectively followed children, including 40 born by Caesarean Section. Proinflammatory serum cytokine concentrations were determined at age 6 months. As a measure of vaccine response, IgG1, IgG2, and IgG4 tetanus antibody titers and CD4+ T cell proliferation against tetanus toxoid were quantified. Compared to infants born by vaginal delivery, infants born by Caesarean Section had lower concentrations of the cytokines IFN-ɣ (p = 0.014) and IL-8 (p = 0.005), and weaker CD4+ T cell responses to tetanus measured in the first (p = 0.007) and second year (p = 0.047) of life. Overall, our findings provide evidence that the mode of delivery influences the immune status and responsiveness during childhood.