Infections Increase Type 1 Diabetes Risk

Infections in the first months of life predispose to the later presence of autoantibodies, which are responsible for the development of type 1 diabetes. In particular, respiratory diseases in the first year of life, especially an acute common cold (nasopharyngitis) appear to play an important role.

Islet autoimmunity refers to the presence of autoantibodies against insulin-producing beta cells of the pancreas. It is characteristic of type 1 diabetes and most commonly appears between the ages of six months to three years. Scientists at the Institute of Diabetes Research have investigated whether in this phase of life infectious agents might be considered a potential trigger for the dysregulation of the immune system. They analyzed the data of children of the BABYDIET study who have relatives with type 1 diabetes and thus an increased risk for islet autoimmunity. The parents kept a log of the infections occurring in the first three years of life of the children – differentiated according to respiratory tract, gastrointestinal tract and other infections. Fever and medication were also recorded and the blood of the children was regularly analyzed for autoantibodies.

In the first year of life an association between respiratory infections and the presence of islet autoantibodies was observed – especially with infections of the upper respiratory tract such as nasopharyngitis (the common cold). Children with islet autoantibodies were infected at least twice in the first year, mainly with pathogens of the respiratory tract. Children who had more than five respiratory infections in the first year had the highest risk of islet autoimmunity.

The scientists suspect, however, that the increase in autoimmune risk is not caused by a specific virus but rather by the sum of infections and the thus released inflammatory cytokines. According to the principal investigator of the study, Anette-Gabriele Ziegler, and her colleagues, frequent respiratory infections in the first year of life represent a possible risk factor for type 1 diabetes. In genetically disposed risk children, multiple episodes of colds in early childhood should be avoided if at all possible, and vaccinations or anti-inflammatory therapies should be taken into consideration as preventive measures against type 1 diabetes.

In islet autoimmunity the immune system is mistakenly directed against endogenous components, namely against various proteins of the insulin-producing beta cells of the pancreas. These cells are gradually destroyed and insulin production is stopped – the outcome is the development of type 1 diabetes.