Coeliac disease (brief)

Question 1

Who does is affect?

Answer 1

Patients mostly are in severe pain with their abdomen feeling rigid or board-like when touched.

Question 2

What causes it?

Answer 2

A strong association exists between coeliac disease and two HLA class 2 molecules, HLA DQ2 and DQ8. The peptide alpha-glidan is the toxic, insoluble part of gluten. It’s resistant to proteases in the small intestinal lumen and passes through a damaged (because of infection or possibly glidan itself) epithelial barrier of the small intestine where it is deaminated by tissue transglutaminase so increasing its immunogenicity. Glidan then interacts with antigen presenting cells in the lamina propria via HLA DQ2 and DQ8 and activates gluten sensitive T cells. The result is an inflammatory cascade and release of mediators contribute to villous atrophy and crypt hyperplasia that are typical histological features of coeliac disease. There is an ↑ in intraepithelial lymphocytes but the pathogenic role of these lymphocytes is not fully known.

Question 3

Risk factors?

Answer 3

HLA-DQ2 and HLA-DQ8 Genes
FHx
Certain other autoimmune conditions

Question 4

How does it present?

Answer 4

Tiredness and malaise, or other symptoms of small intestine disease.

Question 5

Signs on examination?

Answer 5

Usually few and non-specific, and related to anaemia and nutritional deficiency. There is an increased incidence of atopy an autoimmune disease. Dermatitis herpetiformis, itchy symmetrical eruption of vesicles and crusts over the extensor surfaces of the body, with deposition of granular immunoglobulin IgA at the dermoepidermal junction of the skin including areas not involved with the rash.

Question 6

Investigations?

Answer 6

Serum antibodies, IgA tissue transglutaminase (tTG) antibodies have a very high specificity and sensitivity.

Distal duodenal biopsies are required for a definitive diagnosis, as histological changes will be seen.

FBC: mild anaemia found in 50% of cases.

Small bowel radiology or capsule endoscopy, as well as bone densitometry.

Question 7

Treatment?

Answer 7

Gluten free diet and correction of any vitamin deficiencies.

Question 8

DDx?

Answer 8

Bacterial Gastroenteritis

Bacterial Overgrowth Syndrome

Collagenous and Lymphocytic Colitis

Crohn Disease

Cytomegalovirus (CMV)

Cytomegalovirus Colitis

Enteropathy-Type T-Cell Lymphoma

Eosinophilic Gastroenteritis

Giardiasis

Hypoalbuminemia

Hypocalcemia

Hypokalemia

Hypomagnesemia

Hypothyroidism

Immunoglobulin A Deficiency

Inflammatory Bowel Disease

Iron Deficiency Anemia

Irritable Bowel Syndrome

Jejunoileitis

Malabsorption

Non-Hodgkin Lymphoma

Protein-Losing Enteropathy

Viral Gastroenteritis