“Increased cell death was apparent after 8 hours” announce French researchers.
In France, type 1 diabetes affects around 10% of diabetes cases, or 300,000 people. This chronic metabolic disease occurs in half of cases before the age of 20 and is characterized by a dysfunction of the pancreas which does not produce enough insulin, the hormone essential to regulate blood sugar levels. Thus the blood sugar level rises to hyperglycemia. Type 1 diabetes is considered an “autoimmune” disease because the body destroys the cells in the pancreas that are responsible for secreting insulin. The origin of this pancreatic dysfunction remains uncertain. Genetic predisposition is mentioned as well as environmental factors, but not only that.
Recently, French researchers made a major discovery : type 1 diabetes could be linked to a virus, in this case the Coxsackie B virus, according to an international study published in the journal Science Advances and led by the team of diabetologist Roberto Mallone from Cochin hospital (Paris). This virus has been in the sights of researchers for a very long time, in particular because it has often been found in young children at risk of diabetes due to family history. Among children infected with this virus, some of them develop the disease.
To demonstrate the link between this virus and type 1 diabetes, researchers analyzed in the laboratory (in vitro) how the Coxsackie B virus behaved in the body. They were able to show that this virus was capable of specifically killing the cells of the pancreas responsible for producing insulin (the β cells of the islets of Langerhans). “Increased β-cell death was apparent after 8 hours“, specify the researchers in their results. This massive destruction would lead to “latent” inflammation of the tissues and would release proteins wrongly recognized by the cells of the immune system of people genetically predisposed to diabetes. “Scrambled”, the immune system would get into a second step to produce autoantibodies which would attack the individual’s own cells. This is the very principle of autoimmune diseases such as type 1 diabetes.
A virus that does not give symptoms…
Part of the Picornaviridae family and the Enterovirus genus, the Coxsackie B virus is well known to scientists and is widespread throughout the world. Coxsackie B virus infections are mostly asymptomatic and resolve spontaneously. However, they can also progress to a variety of rare conditions such as sepsis, meningoencephalitis, myocarditis or pneumonia. They can affect all age groups, but they are more “common during childhood”, they specify. The virus enters the body through the mouth through fecal-oral transmission (the person becomes infected by putting fingers, objects, drinks or food contaminated by feces into the mouth). It can also be contracted through secretions from infected mucous membranes.
After the discovery of these researchers, the challenge is to detect the disease as early as possible to be able to stabilize it as best as possible. In the longer term, a vaccine could be developed to prevent Coxsackie B infections, a serum which does not yet exist today.