Understanding coeliac disease

Explore the various facets of coeliac disease, an autoimmune condition triggered by gluten. In his latest online article, Dr Simon Smale covers genetic factors, environmental triggers, immune system changes, clinical presentations, and treatment methods.

What is coeliac disease?

Coeliac Disease arises from an autoimmune response triggered by gluten, a specific protein in wheat. This reaction occurs in individuals with a genetic predisposition upon exposure to gluten and environmental factors.

Genetic factors and immune response coordination

Genetic factors associated with coeliac disease involve specific genes related to immune response coordination, known as Human Leukocyte Antigens (HLAs). Those susceptible typically carry HLA DQ2 or DQ8, present in 10-20% of the population. However, only a fraction of these individuals with these proteins develop the disease.

Environmental triggers: Unveiling the role of gluten exposure

Exposure to gluten, found in wheat products, is a crucial factor in coeliac disease development. Individuals with HLA DQ2 or DQ8 usually remain disease-free unless exposed to environmental triggers like rota-viruses and enteroviruses. These viruses may infect the gut, potentially increasing gut lining permeability and triggering irreversible changes in the immune system.

Path to inflammation: Immune system alterations and bowel lining impact

The altered immune system leads to inflammation in the lining of the bowel. In classical coeliac disease, the finger-like villi in the gut, optimising absorptive surface, undergo atrophy, and crypts deepen. The severity of these changes is classified using the Marsh classification, ranging from zero (normal) to four (complete flattening of the villi with significant inflammatory cell infiltration).

Clinical presentation: Symptoms and diagnosis

Patients with coeliac disease may present with gut symptoms, abdominal pain, bloating, diarrhoea or constipation, failure to thrive, weight loss, or anaemia. Some individuals remain asymptomatic and are diagnosed during investigations for other conditions.

Treatment: Gluten exclusion and mucosal healing

The primary treatment for coeliac disease involves a strict gluten-free diet. This approach promotes mucosal healing and normalisation of the immune response, provided there is no accidental gluten ingestion. In cases where patients do not respond to gluten exclusion, it may be due to unintentional gluten intake (resistant Coeliac disease - Type 1).

Special considerations:

In uncommon instances known as Resistant coeliac disease - Type 2, some patients exhibit persistent immune responses despite a strict gluten-free diet. These cases may require specific drug therapy due to the risk of small bowel T-cell lymphoma (Resistant Coeliac disease - Type 2).

Dr Simon Smale is an esteemed gastroenterologist with over 25 years of experience. You can schedule an appointment with Dr Smale on his Top Doctors profile.