In celiac disease, what triggers an immune response in the body?

In celiac disease, the immune response is specifically triggered by gluten, which is a protein found in certain grains such as wheat, barley, and rye. When individuals with celiac disease consume gluten, their immune system mistakenly identifies it as a threat and launches an inflammatory response that damages the lining of the small intestine. This immune reaction can lead to various gastrointestinal symptoms and other systemic effects.

Gluten's role in celiac disease differentiates it from other substances such as lactose, fructose, and casein, which are not involved in the pathophysiology of this autoimmune condition. Lactose is a sugar found in milk and dairy products, fructose is a sugar found in fruits, and casein is a protein found in milk. These substances can cause digestive issues for some individuals, particularly those with lactose intolerance or fructose malabsorption, but they do not trigger the immune response associated with celiac disease. In summary, gluten is the specific substance that initiates the pathologic immune response in individuals with celiac disease.