Makindo Medical Notes

Related Subjects: |Osteoporosis

Coeliac Disease

Coeliac disease is associated with an increased risk of various malignancies, including lymphomas, squamous cell carcinoma of the oropharynx and oesophagus, and small bowel adenocarcinoma. New symptoms should always be taken seriously as they may indicate complications or malignancy.

About

• Coeliac disease is a common autoimmune condition where ingestion of gluten (a protein found in wheat, rye, and barley) triggers an immune response, causing damage to the small intestine.
• It can affect people of all ages, including children, with a prevalence of about 1 in 100 in Western countries. In the UK, the incidence is around 1 in 2000, and it is most common in the west of Ireland (1 in 300).
• Coeliac disease can develop at any age, so re-testing is recommended if symptoms appear later in life.

Aetiology

• Triggered by gluten sensitivity, specifically the alpha-gliadin component of gluten.
• Results in chronic malabsorption due to subtotal villous atrophy in the small intestine.
• Immune response: T-cell-mediated chronic inflammatory response to gliadin peptides, particularly epitopes 57-75, leads to intestinal wall damage via gamma interferon.
• Genetics: Strongly associated with HLA-DQ2 or HLA-DQ8 alleles (95% of patients).
• Increased prevalence among diabetics and those with other autoimmune disorders.

Clinical Features

• Can present at any age but is most common in childhood and adolescence.
• In infants and young children:
  • Failure to thrive, abnormal stools between 8-24 months.
  • Abdominal distension, wasted buttocks, short stature.
  • Anaemia, irritability.
• Symptoms in older children and adults include abdominal pain, fatigue, arthralgia, headaches, and more severe malabsorption signs such as steatorrhoea, diarrhoea, and altered bowel habits.
• Malabsorption complications: Deficiency in fat-soluble vitamins (A, D, E, K), iron, and folate, leading to osteoporosis, osteomalacia, and anaemia.
• Dermatitis herpetiformis: Itchy blisters typically on elbows, knees, and buttocks, present in a subset of patients.

Investigations

• Blood tests:
  • Anaemia: Microcytic (iron deficiency, low ferritin) or macrocytic (folate deficiency). B12 deficiency is less common.
  • Low albumin, calcium, and phosphate: Raised alkaline phosphatase indicates vitamin D deficiency and malabsorption of calcium.
  • Prolonged PT: Due to vitamin K deficiency.
  • Howell-Jolly bodies: Indicative of hyposplenism.
• Serology: IgA anti-tissue transglutaminase (tTG) is highly sensitive and specific (95%) but may be negative in patients who have already started a gluten-free diet (GFD).
• Anti-endomysial antibodies: Useful if tTG is negative; test for total IgA as IgA deficiency is more common in coeliac patients.
• Endoscopy with biopsy: Multiple distal duodenal biopsies are needed, as villous atrophy may be patchy. Histology reveals subtotal villous atrophy, with lymphocytic and plasma cell infiltration in the lamina propria.

Differential Diagnosis

• Tropical sprue, cystic fibrosis, milk protein enteropathy.
• Infectious causes: giardiasis.
• Other conditions: chronic pancreatitis, abetalipoproteinaemia.

Management

• Strict lifelong gluten-free diet (GFD): Avoid all wheat, rye, and barley products to prevent symptoms and complications.
• Monitor antibody levels: Falling antibody levels can be a useful indicator of dietary adherence.
• Some patients may require steroids in severe cases to reduce inflammation.
• Consider re-endoscopy in some patients to assess histological improvement, particularly if symptoms persist.
• Screening of family members: Coeliac disease has a genetic component; relatives may benefit from screening.

Complications

• In children: Growth retardation, delayed puberty.
• Bone health: Osteopenia and osteoporosis due to malabsorption of vitamin D and calcium.
• Increased risk of certain cancers: Small bowel adenocarcinoma, oesophageal squamous cell carcinoma, and non-Hodgkin’s lymphoma.
• Hyposplenism (reduced splenic function).
• Possible reduced risk of breast cancer in some studies.

References

• Coeliac UK: Information and Resources