Coeliac disease Flashcards
What is coeliac disease?
an autoimmune disease that is characterised by gluten insensitivity.
What percent of the UK is affected by coeliac disease?
around 1 %
Are women or men more likely?
Women
What age range is mostly affected by coeliac disease?
when children are exposed to solid foods
40-50 year old
What is the aetiology of coeliac disease?
In coeliac disease, gliadin, a component of gluten, is not broken down fully and passes through the intestinal epithelial layer triggering an immune response.
Gliadin binds to HLA DQ2 or DQ8 which activates T-cells in the intestinal mucosa leading to the immune response. The immune response results in chronic inflammation within the small bowel, damaging the epithelium and ultimately resulting in malabsorption.5
Almost all patients with coeliac disease are HLA DQ2 positive and many are also DQ8 positive.
what are the risk factors for coeliac disease?
- Genetics (around 70% if monozygotic twin affected)
- Autoimmune thyroid disease
- Genetic syndromes eg Down’s and william’s syndrome
- Type 1 diabetes mellitus
- IgA deficiency
What are the symptoms of coeliac disease in children?
- Failure to thrive (stunted growth, growth chart faltering)
- Chronic diarrhoea
- Constipation (coeliac disease should be considered whenever diagnosing idiopathic constipation)
- Abdominal bloating
- Irritability
- Features of anaemia (adolescents)
Children normally present with these symptoms in the first few years of life as gluten products are introduced to their diets.
What are the typical symptoms of coeliac disease in adults?
- Long-standing diarrhoea (may be intermittent in nature)
- Nausea and vomiting
- Fatigue (patient often have underlying iron-deficiency anaemia)
- Weight loss
What other areas are important areas to cover in the history?
- Family history - coeliac disease often runs in families
- associated conditions
What is the mnemonic for conditions associated with coeliac disease?
Mnemonic: “I Don’t Take Apples, I Take Oranges”
What does the Mnemonic: “I Don’t Take Apples, I Take Oranges” stand for?
IgA deficiency
Down’s syndrome
Turner’s syndrome
Autoimmune thyroid disease and autoimmune hepatitis
IgA nephropathy
Type 1 diabetes mellitus
Other autoimmune conditions (e.g. Sjögren’s, myasthenia gravis, Addison’s disease)
What specific antigen activates the autoimmune reaction in coeliac disease?
gliadin antigen
What are the 3 antibodies produced in coeliac disease:
1) anti-tissue transglutaminase antibodies (anti-TTG)
2) anti-endomysial antibodies (anti-EMA)
3) anti-deaminated gliadin peptide antibodies (anti-DGP)
Which region of the small intestine is mainly affected by coeliac disease?
jejunum
Give 3 features of bowel inflammation seen in coeliac disease:
1) villous atrophy
2) crypt atrophy
3) increased intraepithelial lymphocytes
What clinical features may be identified in children with coeliac disease?
- Abdominal distension
- Abdominal wasting
- Muscle wasting
- Features of anaemia
What clinical features may be identified in adults with coeliac disease?
- Features of anaemia
- Mouth ulcers
- Weight loss
- Anxiety features
- Joint pain
- Abdominal pain
- Dermatitis herpetiformis
What are 8 extra-intestinal manifestations of coeliac disease?
- Arthritis
- Dermatitis herpetiformis
- Osteoporosis/ osteopenia
- Infertility
- Ataxia
- Epilepsy
- Anxiety
- Depression
What is the effect of villous atrophy on digestion and nutrition?
malabsorption of nutrients such as iron and B12/folate
Which 2 human leukocyte antigens are associated with coeliac disease?
1) HLA-DQ2
2) HLA-DQ8
What is dermatitis herpetiformis?
an itchy, blistering skin rash, typically on the abdomen caused by coeliac disease
Explain why coeliac disease can cause anaemia:
malabsorption of iron, B12 and folate
How is coeliac disease usually diagnosed?
Based on immunological investigation results and the histology of small bowel biopsies.
Give 3 (rare) neurological symptoms associated with coeliac disease:
1) peripheral neuropathy
2) cerebellar ataxia
3) epilepsy
True or false: when investigating coeliac disease, the patient must continue to eat gluten
true (the antibody level and histology may return to normal if the patient is gluten free)
What are the two first line blood tests used to investigate coeliac disease?
1) total immunoglobulin A (to exclude IgA deficiency)
2) anti-tissue transglutaminase antibodies (anti-TTG)
Why do we test for IgA deficiency when investigating coeliac disease antibodies?
coeliac antibodies are all IgA antibodies - a deficiency may lead to false negatives
What is the next step in investigating coeliac disease following positive serum antibody tests?
1) endoscopy
2) jejunal biopsy
via gastroenterologist referral
What are the 4 key changes seen on a duodenal biopsy in those with coeliac disease?
- Presence of villous atrophy leading to a flat mucosa
2.Crypt cell hyperplasia - Intraepithelial cell lymphocytosis
- Inflammatory cell infiltration of the lamina propria
What is the name of the histological classification used to grade the severity of coeliac disease?
Marsh-Oberhuber classification
Describe the histological findings of a grade 1 Marsh-Oberhuber coeliac biopsy:
increased intraepithelial lymphocytes
Describe the histological findings of a grade 2 Marsh-Oberhuber coeliac biopsy:
crypt hyperplasia
Describe the histological findings of a grade 3 Marsh-Oberhuber coeliac biopsy:
villous atrophy
Name 3 additional investigations used to rule out complications in coeliac disease:
1) FBC and blood screen (anaemia)
2) B12/folate levels
3) bone DXA scan (risk of osteoporosis)
What is the main management for coeliac disease?
life-long gluten free diet (wheat, barley, rye)
Give 8 complications associated with coeliac disease:
1) ulcerative jejunitis (fever, pain, bleeding)
2) osteoporosis
3) anaemia
4) nutritional deficiencies
5) enteropathy-associated T-cell lymphoma
6) non-Hodgkin lymphoma
7) small bowel adenocarcinoma
8) hypersplenism
What are 6 differential diagnoses for coeliac disease?
- Anorexia nervosa
- Bacterial overgrowth of the small bowl
- Crohn’s disease
- Irritable bowel syndrome
- Lactose intolerance
- Autoimmune enteropathy
