Diabetes and Viral Infection

Abstract

Type 1 diabetes (T1D) results from the autoantibody destruction of insulinproducing β-cells in the pancreas, particularly in early childhood. In addition to, immunological and genetic factors, the environmental factors such as viruses are believed to contribute to the type 1 diabete development. Various studies have detected certian viruses in the the pancreas of type 1 diabetic patients and found link between these viruses and T1D development using different techniques. Based on the epidemiological studies the enteroviruses, especially the coxsackievirus B, are the most common viruses found in type 1 diabetic patients. Virus infection might target β-cells and induce strong inflammation in the pancreatic β -cells, causing the initial step in autoimmunity induction. This review summarize the role of some viruses in the development of type 1 diabetes. Copyright: ©2017 Shaheen between respiratory infections during the early life (first year) of children and islet autoimmunity [27,28]. In Swedish study, the developing islet autoantibodies can be increased in the pregnant woman who infected with enterovirus in early pregnancy [29].In contrast, two studies of Finnish and Norwegian children at genetic risk of T1D did not find association between influenza A and Saffold viruses and the development of risk for islet autoimmunity [30,31]. Certain gut microbes (e.g. hepatitis A virus and Helicobacter pylori) are associated with development of lower risk of T1D [32].In the opposite direction, some authors reported that the enterovirus infections can induce protection against autoimmune disease [33,34]. This idea (Hygiene Hypothesis) hypothesis that fewer infections could increase the risk of autoimmune diseases, than people who get recurrent infection in their early childhood. In animal models, fewer infections showed increase in the development of autoimmune disease, while more infections at an early age protected the mice against diabetes (interestingly, infections in some animal models are not necessarily in protection against autoimmune disease) [33]. However, Beyerlein et al. [27] reported that the recurrent infection with respiratory virus in the first yrar of life were associated with an increased risk of T1D by age 8.Tracy et al. [34] suggested that induction or protection of viruses against T1D depends on several factors such as an individual's genetics, the type of virus and its dose, the age of the individual, and whether the individual has previous immunity to that virus. However, one study found the living of children (0-3 years but not in later life) in crowded houses was associated with an increased risk factors of developing T1D [35]. In study of all babies born in Southeast Sweden (1997)(1998)(1999) find a weak link between previous gastrointestinal infections and development of T1D [36]. Virtanen et al. [37] did not find link between the microbial exposure in the first year of life of children without an indoor dog exposure and T1D, while the exposure of children during early life to an indoor dog ...