Scientists Find Molecular Trigger for Celiac Disease
People with celiac disease have an immune system response to gluten, a protein found in wheat, which damages the lining of the small intestine. Currently, the only treatment is the adoption of a strict gluten-free diet – difficult, because so many foods contain wheat flour as an ingredient.
Researchers from the Walter and Eliza Hall Institute of Medical Research in Australia believe they have identified molecular triggers of celiac disease, which could lead to the first drugs to treat the condition.
Robert Anderson, senior author of the study and head of the celiac disease research laboratory, analyzed the immune responses in the blood of more than 200 celiac disease patients after they had consumed meals containing gluten. Blood samples were screened for responses to thousands of different protein components of the gluten protein.
Gluten consists of many different protein components, called peptides, but it has been unclear which of these fragments specifically induce the immune system response seen in celiac patients. “You can’t design drugs for celiac disease until you know the parts of the gluten that are driving the condition,” said Anderson.
Ninety peptides in gluten caused some level of immune reaction, but three were found to be particularly toxic. Pinpointing these peptides has opened the door for development of a therapeutic vaccine that may help celiac patients better tolerate gluten.
Anderson’s company, Nexpep, has created one such a drug and is now conducting phase I clinical trials. The aim of the drug is to desensitize celiac patients to the offending proteins by presenting them in controlled amounts. They expect the results within the next couple of months.
The researchers also noted that most of the immune response to gluten appears tied to a single type of immune system cell, called the T cell.
The findings may not be relevant to everyone with celiac disease, since the participants in the study had a particular genetic susceptibility to the disease. Although most people with celiac show this genetic background, some do not.
About 150,000 people in the US have been diagnosed with celiac disease, but the actual number affected might be closer to 3 million. In the past 60 years, the number of people diagnosed has increased 5-fold, according to Anderson.
The results of the study are published in the July 21 issue of Science Translational Medicine.