A new study suggests a link between a specific group of common viruses, enteroviruses, and the development of type 1 diabetes (T1D). This study, part-funded by JDRF, isn’t the first to find this link but the authors say it’s the largest and most definitive study of its kind to date.
Professor Keikki HyÖty and Dr Hanna Honkanen led this study published in Diabetologia at the University of Tampere in Finland. They found that children at high risk of T1D who then go on to develop the disease, had a higher number of enterovirus infections compared to those without the disease.
The study included 129 children who had already been identified as having an increased genetic risk of T1D, and who had at least two of the relevant autoantibodies linked to T1D development present at the start of the study. They were compared to a control group of 282 children, who had no evidence of T1D risk. The control group children were matched to the children with T1D for area of residence, gender, and date of birth, and these children also all remained autoantibody negative throughout the study. Stool samples were collected for analysis once a month starting from the age of three months up until 2-3 years old, to test for the enteroviruses.
The researchers found 108 enterovirus infections in the group of children with T1D (0.8 infections per child) vs. 169 enterovirus infections in the 282 control group children (0.6 infections per child). Altogether, 25 different enteroviruses were detected in all of the children’s samples throughout the duration of the study, however no single type of enterovirus showed a particular association with type 1 autoantibodies.
This is an important study adding to the body of evidence relating to environmental factors contributing to T1D. Importantly in this study, the researchers were able to show there was a lag time of about one year between enterovirus infection and autoantibodies appearing.
Not all people with T1D had evidence of enterovirus infections, indicating that that there are many other factors involved in the autoimmune process leading to T1D. This study was only able to show an association, but not a causal effect of enterovirus in T1D. This study was undertaken in young people in Finland, and it is known that enterovirus infections differ between populations. Further studies throughout the world are needed to see if this association is seen in different areas, and different age groups.
What does this mean for people with T1D?
It is important to understand what causes T1D before we can prevent the disease. Studies such as this continue to build a picture of the factors leading to T1D. If further studies continue to find associations between particular types of viruses and the development of T1D, then there is hope that in future a vaccine could be developed to prevent enterovirus infection in people at risk of T1D.
What’s happening in Australia in this space?
In Australia, the JDRF T1DCRN funded Environmental Determinants of Islet Autoimmunity (ENDIA) study is investigating factors during development that lead to islet autoimmunity and T1D. This is the only study of its kind worldwide investigating these factors before birth. ENDIA is following babies with a first degree relative with T1D from pregnancy through to early childhood, and measures environmental factors such as bacteria and viruses, body growth and food exposures. This study will help to give more insight into what might be causing or protecting against T1D, including the possible role of viruses.
ENDIA is recruiting at major hospital across Australia, including a regional program for those who live in rural areas. Head to the ENDIA website to find out more or watch this video. To contact the ENDIA team, use the contact form or call (08) 8161 8747.