A common gastric virus may trigger diabetes, scientists have found, raising hopes that a vaccine can be developed.
Two separate teams of British researchers found strong evidence that enterovirus infection can trigger the immune reaction which leads to insulin-dependent diabetes. There was also a suggestion that viral infection may be involved in Type 2 diabetes, although how is not clear.
The virus family, which includes more than 100 different strains, can cause vomiting and diarrhoea but often produces no symptoms. By attacking insulin-producing beta cells in the pancreas, it is thought the viruses set off an immune response which spins out of control, leading to Type 1 diabetes.
The disease occurs when pancreatic beta cells are destroyed by the body's immune system. Developing a vaccine against the viruses could potentially prevent this happening, researchers believe. But more work is needed to identify which strains of enterovirus should be targeted.
Type 1 diabetes affects about 300,000 people in the UK, including 20,000 children under 15. Having lost their beta cells, patients must rely on insulin injections to regulate their blood sugar and stay alive. A further 2.2 million people are known to suffer from Type 2 diabetes, which is not an auto-immune disease and is related to lifestyle.
One team of researchers studied a unique Scottish collection of pancreases from 72 young people who died less than a year after being diagnosed with Type 1 diabetes. In 60 per cent of cases, the organs contained evidence of beta cell infection by enteroviruses.
Pancreases of 50 deceased children who had not suffered from diabetes showed virtually no sign of viral infection. It was already known that children who develop Type 1 diabetes inherit a genetic susceptibility to the disease. But studies of identical twins show that when one sibling has the condition, the other only has a 40 per cent chance of developing it. Since identical twins share the same genetic make-up, this suggests that non-genetic factors must be involved.
The research was reported yesterday in the European diabetes journal Diabetologia.