Does a virus trigger the development of type 1 diabetes?
What is the problem and what is known about it so far?
No one knows what causes type 1 diabetes, but researchers believe it is some combination of genetic and environmental factors. One theory is that, given the right genetic background, viral infections can trigger the immune system to incorrectly target the pancreatic cells that make insulin as though they were foreign invaders. This theory suggests that it may be possible to make a vaccine for type 1 diabetes if the offending virus can be identified. Past studies have linked a class of viruses called enteroviruses with the development of type 1 diabetes.
Why did the researchers do this particular study?
Not all studies have found an association between enteroviruses and diabetes, leading researchers to wonder if only particular members of this class of viruses increase the risk for type 1 diabetes. The researchers in this study hoped to identify specific enteroviruses with connections to diabetes.
Who was studied?
The study included 183 children either with type 1 diabetes or at high risk for developing type 1 diabetes as indicated by blood tests that check for autoantibodies. These molecules suggest that the immune system is actively targeting the insulin-producing cells of the pancreas. The study also included 366 children without autoantibodies and at low risk for developing type 1 diabetes.
How was the study done?
The researchers originally enrolled participants when they were first born, selecting children with genes that increase the risk for type 1 diabetes. They then collected blood samples from the participants—as well as a group of children without the diabetes genes for comparison—at the ages of 3, 6, 12, 18 and 24 months, then once a year after that. The researchers tested the children's blood for diabetes autoantibodies as well as for virus-related proteins that they used to identify and distinguish between infections from 44 strains of enterovirus.
What did the researchers find?
A virus called coxsackievirus B1 was associated with an increased risk of developing type 1 diabetes, while two other coxsackieviruses, B3 and B6, were associated with a lower risk.
What were the limitations of the study?
The study only included people from Finland and looked at a limited 10-year period.
What are the implications of the study?
This study suggests that developing a vaccine for coxsackievirus B1 may prevent some cases of type 1 diabetes, but more research is needed to confirm that this virus causes type 1 diabetes.