Causes of Coeliac Disease
Causes of coeliac disease involve a mix of genetic predisposition, gluten exposure, and abnormal immune system reactions. While the precise origin of coeliac disease is still under investigation, extensive research has confirmed that individuals must have specific genetic markers and be exposed to gluten to develop the condition. Environmental and immune-related factors then interact to trigger the disease.
The primary genetic link to coeliac disease lies in the HLA-DQ2 and HLA-DQ8 genes. Over 95% of people diagnosed with coeliac disease carry the HLA-DQ2 variant, while most of the remaining cases carry HLA-DQ8. These genes are involved in presenting gluten-derived peptides to immune cells. However, having these genes is not enough to cause the disease — they simply increase the risk. Around 30% of the population has these genes, yet only a small proportion ever develop coeliac disease.
Causes of Coeliac Disease
Gluten consumption is the essential environmental factor. For those genetically predisposed, gluten exposure can lead to an inappropriate immune response that damages the small intestinal lining. The body produces autoantibodies, especially against tissue transglutaminase (tTG), an enzyme involved in digesting gluten. These antibodies attack the villi in the small intestine, flattening them and reducing the ability to absorb nutrients effectively.
Environmental triggers are believed to play a role in activating the disease in genetically susceptible individuals. Factors such as early childhood infections, changes in gut microbiota, pregnancy, surgery, or significant emotional stress can disturb immune balance and promote disease onset. Studies also suggest that timing and quantity of gluten introduction in infancy may influence disease development, although evidence remains inconclusive.
First-degree relatives of those with coeliac disease have a 10–15% risk of developing the condition. Therefore, family history plays a significant role in identifying at-risk individuals. Twin studies also support a strong genetic component, with identical twins having up to a 75% concordance rate.
Causes of Coeliac Disease
Additionally, coeliac disease often coexists with other autoimmune conditions, such as type 1 diabetes, autoimmune thyroid disease, and rheumatoid arthritis. This clustering further highlights its immune-mediated nature.
To summarise, the causes of coeliac disease are multi-factorial, involving genetic susceptibility, exposure to gluten, and immune dysfunction. Understanding these causes helps identify at-risk individuals and promotes early screening, which is crucial for reducing long-term complications and improving outcomes.
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