Malabsoroption (coeliac disease)

Question 1

What is coeliac disease?

Answer 1

Coeliac disease is an autoimmune condition where exposure to gluten causes an autoimmune reaction that causes inflammation in the small bowel. It usually develops in early childhood but can start at any age.

Question 2

Autoantibodies in coeliac

Answer 2

In coeliac disease auto-antibodies are created in response to exposure to gluten that target the epithelial cells of the intestine and lead to inflammation. There are two antibodies to remember: anti-tissue transglutaminase (anti-TTG) and anti-endomysial (anti-EMA). These antibodies relate to disease activity and will rise with more active disease and may disappear with effective treatment.

Question 3

Where does inflammation occur?

Answer 3

Inflammation affects the small bowel, particularly the jejunum. It causes atrophy of the intestinal villi. The intestinal cells have villi on them that help with absorbing nutrients from the food passing through the intestine. The inflammation causes malabsorption of nutrients and the symptoms of the disease.

Question 4

how does coeliac disease present?

Answer 4

Failure to thrive in young children
Diarrhoea
Fatigue
Weight loss
Mouth ulcers
Anaemia secondary to iron, B12 or folate deficiency
Dermatitis herpetiformis (an itchy blistering skin rash typically on the abdomen)
Rarely coeliac disease can present with neurological symptoms:

Peripheral neuropathy
Cerebellar ataxia
Epilepsy

Question 5

What other condition to test for?

Answer 5

we test all new cases of type 1 diabetes even if they don’t have symptoms as the conditions are often linked.

Question 6

Genetic associations

Answer 6

HLA-DQ2 gene (90%)

HLA-DQ8 gene

Question 7

What autoantibodies?

Answer 7

Tissue transglutaminase antibodies (anti-TTG)
Endomysial antibodies (EMAs)
Deaminated gliadin peptides antibodies (anti-DGPs)

Some patients have an IgA deficiency. When you test for these antibodies, it is important to test for total Immunoglobulin A levels because if total IgA is low because they have an IgA deficiency then the coeliac test will be negative even when they have coeliacs

Question 8

Investigations

Answer 8

Investigations must be carried out whilst the patient remains on a diet containing gluten otherwise it may not be possible to detect antibodies or inflammation in the bowel.

Check total immunoglobulin A levels to exclude IgA deficiency before checking for coeliac disease specific antibodies:

Raised anti-TTG antibodies (first choice)
Raised anti-endomyseal antibodies
Endoscopy and intestinal biopsy show:

“Crypt hypertrophy”
“Villous atrophy”

Question 9

Associated conditions

Answer 9

Type 1 Diabetes
Thyroid disease
Autoimmune hepatitis
Primary biliary cirrhosis
Primary sclerosing cholangitis

Question 10

Complications of untreated coeliac disease

Answer 10

Vitamin deficiency
Anaemia
Osteoporosis
Ulcerative jejunitis
Enteropathy-associated T-cell lymphoma (EATL) of the intestine
Non-Hodgkin lymphoma (NHL)
Small bowel adenocarcinoma (rare)

Question 11

Treatment

Answer 11

Lifelong gluten free diet is essentially curative. Relapse will occur on consuming gluten again. Checking coeliac antibodies can be helpful in monitoring the disease.