Two studies conducted in March at the Peninsula Medical School in the South West of England, the University of Brighton and the Department of Pathology at Glasgow Royal Infirmary provide evidence that common viruses may cause childhood Diabetes, paving the way for potential vaccines against the the disease, researchers said.
One team showed that enteroviruses — which normally cause colds, vomiting or diarrhea — were found frequently in the pancreases of young people who had recently died from type 1 diabetes, sometimes called juvenile diabetes, but not in healthy samples. This was a detailed study of a unique collection of pancreases from 72 young people who died less than a year after the diagnosis of type 1 diabetes.
This suggests a virus could trigger the disease in children genetically predisposed to the condition, which affects an estimated 440,000 people worldwide, said Alan Foulis of the Royal Infirmary in Glasgow, who worked on one of the studies.
Type 1 diabetes usually starts in young children and results from the destruction of the insulin-producing beta cells in the pancreas. Patients who develop type 1 diabetes have to take several daily injections of insulin for the rest of their lives. The condition affects around 300,000 people in the UK , including 20,000 children under the age of 15. There are a further estimated 440,000 cases of type 1 diabetes in children worldwide, with more than a fifth living in Europe.
It is thought that children who develop type 1 diabetes inherit a genetic susceptibility to the disease, but studies of identical twins have shown that when one twin has the disease, the other twin will only have approximately a 40 percent chance of developing diabetes – suggesting that other factors are involved.
By contrast, the researchers hardly ever saw infected beta cells in tissue samples taken from 50 children without diabetes, they reported in the journal Diabetologia.
The researchers also found a large proportion of these infected cells in adults with the more common type 2 diabetes, suggesting that viruses may also trigger this form of the disease in some people as well.
A second study from Cambridge University researchers found that rare genetic mutations in a gene involved with the body’s response to viruses reduce the risk of juvenile diabetes.
They looked at 480 young people with type 1 diabetes and another 480 healthy people to identify the gene and the variants involved.
“We have pinpointed a specific gene, which acts as a warning report for virus infection,” John Todd, a Cambridge University researcher, who worked on a study published in the journal Science. “Not only have we found a specific gene but this gene also has an intriguing function in dealing with virus infection.”
While Todd stated that many environmental factors besides viruses could be contributing to type 1 diabetes, Foulis and his team said they wanted to whittle down the some 100 enteroviruses to find which ones played the main roles.
Doing this, and better understanding of how cells respond to viral infection, are steps toward a vaccine that could one day protect children against diabetes, Foulis said.
“The aim would be for a vaccine that would prevent many cases of type 1 diabetes,” he added.