A team of researchers from the University of Pittsburgh and University of Chicago conducted a study that found a specific type of virus could trigger the immune system to overreact to gluten and lead to celiac disease. The findings provide a genuine explanation for why some, but not all people develop celiac disease.
“This is the first study to show that a virus can change the way our diet is seen by the immune system,” said lead author, Dr. Bana Jabri of the University of Chicago Celiac Disease Center. The virus turns off the body’s “peacekeeper” response to gluten, tricking the immune system into thinking gluten is a harmful invader that needs to be attacked.
The research team induced mice with reoviruses (orthoreoviruses), nonenveloped, RNA viruses that typically does not make people sick. The infected mice experienced a supercharged immune response when they were fed gluten, leading to the development of the inflammation related to celiac disease. The mice that were not induced with reoviruses developed a much milder response to gluten.
Jabri says these results were similar in human patients. Blood samples obtained from individuals with celiac disease revealed more antibodies to reoviruses compared to healthy people. These people were also found to have more of the celiac disease inflammation than healthy people.
Jabri said, “whether a person was infected with reoviruses at some point in the past could explain why they develop celiac at a certain age or had worse symptoms compared to others, who were not infected”.
According to the director of the Celiac Center at New York-Presbyterian/Columbia University Medical Center, Dr. Peter Green, nearly 40 percent of the population has the HLA-DQA1 and HLA-DQB1 genes that are linked to celiac disease and even though 95 percent of people eat gluten regularly, only 1 percent will end up developing celiac disease.
“This study demonstrates the mechanism that a viral infection can cause a switch in the immune system that results in the development of food intolerance,” said Green. He says further study might show that other organisms such as bacteria do the same.
An estimated 3 million Americans have celiac diseases, but only 3 percent have been diagnosed, according to the Centers for Disease Control and Prevention (CDC).
Celiac disease is classified as an autoimmune disease, in which an abnormal immune response to gluten causes irritation in the small intestine, leading to nutrient malabsorption and tissue inflammation. Symptoms of celiac disease include, but not limited to: diarrhea, constipation, heartburn, fatigue, iron-deficiency anemia, headaches and mood problems.
The director of the Celiac Disease Clinic at Johns Hopkins School of Medicine told NBC, the reovirus link to an autoimmune response in the gastrointestinal system makes sense.
“We have more viruses in our gut than bacteria and we know very little about what they do as this point,” said Mullin.
The findings were published on April 7 in the journal Science.