Type 1 diabetes is an autoimmune disease– that is, a disease resulting from the immune system attacking the body. In the case of type 1 diabetes, the immune system mistakenly attacks the beta cells in the pancreas that produce insulin, and without insulin-producing beta cell function, one develops type 1 diabetes, and quickly. Researchers still are not 100% sure what causes type 1 diabetes, but many believe that a virus can “trigger” the body into attacking itself, resulting in disease.
Why does this happen? When a virus invades the body, the immune system starts to produce a response to fight the infection. T-cells are central to recognizing and fighting off the virus. However, if the virus has some of the same antigens as the pancreatic beta cells (in the case of type 1 diabetes), the T cells sometimes actually start attacking the body’s own beta cells. Once all of the body’s beta cells have been destroyed, type 1 diabetes is developed and diagnosed.
It can take more than a year for the body’s T-cells to destroy the majority of the beta cells, but that original viral infection is hypothesized to be a trigger in the development of type 1 diabetes.
A recent study showed that kids exposed to enteroviruses are more likely to develop type 1 diabetes. Enteroviruses are a group of viruses that usually cause mild symptoms, similar to that of the common cold. Certain strains, such as the poliovirus or hand, foot, and mouth disease, can cause more serious complications.
Researchers in Finland tested more than 1,600 stool samples from 129 children who had recently developed type 1 diabetes and 282 children without diabetes for enterovirus RNA (a marker of previous exposure to infection). They found a significant difference: 60% of the control group showed signs of prior infection (without diabetes), versus 80% of the group with type 1 diabetes.
The results also showed that children who developed type 1 diabetes were exposed to the enterovirus more than a year before their diabetes diagnosis; taking this lag time into account, the researchers proved that children with diabetes are exposed to three times more enteroviruses than children without diabetes.
Researchers are hopeful about current trials, showing vaccines against enteroviruses could potentially prevent 30-50% of new cases of type 1 diabetes, but not all infections can be prevented.
Jessica Dunne, PhD, director of discovery research at JDRF, is excited by the current research. “Enteroviruses are not the only trigger for diabetes, so it’s important to note that even if we prevented all enterovirus infections we probably wouldn’t be able to prevent all cases of type 1 diabetes. I think it would go a long way,” Dunne said.
Clearly, other genetic and environmental facts are at play in the development of type 1 diabetes, but a growing amount of research is pointing to a virus as a common trigger. Other studies have shown that pregnant mothers with antibodies from enteroviruses go on to have children who develop type 1 diabetes.
Not every virus can trigger this reaction ending in disease. The virus must have antigens that are similar enough to the antigens in beta cells (and thus could easily be confused by the immune system); those viruses include:
- B4 strain of the coxsackie B virus
- German measles
There is even new, mounting evidence that the current COVID-19 (SARS-CoV-2 virus) pandemic could be triggering a new wave of type 1 diabetes diagnoses now and into the future.
There is still much debate in the medical community over the exact cause of type 1 diabetes, and most researchers believe it to be a mix of genetics and environmental factors, but the theory of enterovirus-triggered diabetes is gaining support from physicians and researchers alike. There is still much to be explored in the development of type 1 diabetes, but research like this is promising for the eventual development of a vaccine to help prevent new type 1 cases worldwide. Understanding viruses and their connection to the immune system can help unravel the medical mystery of type 1 diabetes without an apparent cause.
What was your experience when you were diagnosed with type 1 diabetes? Were you extremely sick with a viral illness, several months or even years before diagnosis? Do you think a virus could have triggered your diabetes? Share this post and comment with your story, below! We love hearing from our readers.
Read more about beta cells, enterovirus, insulin, Intensive management, JDRF, type 1 diabetes study, vaccination, virus.