Everything you need to know about coeliac disease

This guide contains everything you need to know about coeliac disease including what it is, how it’s treated, available testing for the condition, and how coeliac disease is passed down in families.

What is coeliac disease?

Coeliac disease is an autoimmune disease that develops over time because of a sensitivity to gluten; a protein found in certain cereal grains including wheat, rye, and barley, and commonly used in food products such as cereal, bread, and pasta.

When a person with coeliac disease eats gluten, this causes the body’s immune system to attack its own tissue, causing damage to the gut lining and preventing the body from adequately absorbing nutrients from food.

If left untreated, it can lead to severe complications, which can negatively impact on a person’s quality of life.

Coeliac disease affects around 1 in 100 people in the UK, but only 30% of these people are diagnosed, leading experts to believe that there are many more people suffering with it. This is because milder cases can go undiagnosed or be misdiagnosed as irritable bowel syndrome (IBS).

Is coeliac disease serious?

Coeliac disease can range from mild to severe depending on the person.

Even if the symptoms are mild initially, they can get worse over time if the condition remains undiagnosed or untreated and the person continues to consume foods containing gluten.

Severe complications from undiagnosed/untreated coeliac disease can include osteoporosis, anaemia, certain neurological diseases (affecting the brain and nerves) and, in rare cases, intestinal lymphoma and bowel cancer.

However, with early diagnosis, the disease can be easily managed with a lifelong gluten-free diet.

What are the symptoms of coeliac disease?

Some of the most common symptoms of coeliac disease include:

• An itchy rash (dermatitis herpetiformis)
• Anaemia
• Bloating and flatulence
• Constipation or hard stools
• Diarrhoea or loose stools
• Disorders that affect co-ordination, balance, and speech (ataxia)
• Indigestion
• Nausea, feeling sick and vomiting
• Nerve damage (peripheral neuropathy)
• Stomach aches and cramping
• Tiredness (fatigue) due to not getting enough nutrients from food (malnutrition)
• Unintentional weight loss

What causes coeliac disease?

Coeliac disease is caused by an adverse reaction of the immune system to gluten, a protein found in certain cereals including wheat, barley, and rye.

Research into the condition has shown that coeliac disease runs in families, and those who have a first-degree relative with the condition (i.e. parent, sibling, child) have a higher risk of developing coeliac disease in the future.

Expert geneticists have found that the HLA-DQ2 and HLA-DQ8 genes are the most common genes observed in coeliac disease patients, making genetic testing an effective method for determining the likelihood of developing coeliac disease in the future.

Is coeliac disease genetic?

Coeliac disease can be inherited and often runs in families. Around 1 in 10 people diagnosed with coeliac disease have a first-degree relative (i.e. parent, sibling, child) with the condition.

People with the disease typically have the Human Leukocyte Antigen (HLA) DQ2 and DQ8 genes.

Human Leukocyte Antigen (HLA) generates a protein in the body that binds to any foreign material on the surface of a cell. When people have defective HLA genes, their bodies see gluten peptides as foreign, resulting in an autoimmune reaction.

The HLA-DQ2 and/or HLA-DQ8 genes are always found in people who have been diagnosed with coeliac disease.

However, they are also found in around 25-30% of the UK population, so simply having one or both genes does not mean that an individual currently has or will develop coeliac disease: rather that they are at a higher risk of developing the condition at some point in the future.

Is coeliac disease the same as an allergy?

No, coeliac disease is not the same as a wheat allergy or gluten intolerance/sensitivity.

Coeliac disease is a serious autoimmune condition that develops over time, typically runs in families, and can only be treated by adhering to a strict gluten-free diet.

A wheat allergy occurs when your body produces antibodies to the proteins found in wheat, causing a different kind of immune system reaction. In severe cases, it can lead to anaphylaxis.

A gluten sensitivity or intolerance may cause symptoms similar to those experienced by people with coeliac disease, but it is not clear how the immune system might be involved, no antibodies are produced, and there is seemingly no damage to the gut lining. 

Can you develop coeliac disease over time?

Yes, coeliac disease develops over time and symptoms can start at any age. It is most common among adults aged between 50 and 70.

Women are also three times more likely to develop the disease than men. 

How is coeliac disease diagnosed? Can you test for coeliac disease?

Diagnostic testing for coeliac disease usually includes blood testing for antibodies and, depending on the results of the blood test, a gut biopsy to assess any damage to the gut lining.

However, before undergoing any unnecessary invasive testing, a genetic test for coeliac disease can be a helpful option for determining whether an individual is at risk of having or developing coeliac disease in the future.

A Genetic Coeliac Disease Test uses Human Leukocyte Antigen (HLA) typing to confirm or rule out the potential of developing coeliac disease by analysing six DNA markers for the HLA-DQ2 and HLA-DQ8 genes.

If the test results show that an individual has one or both genes (HLA-DQ2 and/or HLA-DQ8), this indicates that they could be at risk of developing coeliac disease in the future.

The test results will show either a negative result or that the person is at very low, low, moderate, or high risk of developing coeliac disease, depending on which genes they have. This information can then be shared with medical professionals, which can be useful when trying to secure a diagnosis more quickly.

However, it’s important to remember that having these genes does not guarantee that a person will develop coeliac disease or indicate that they are currently suffering from it.

If the test results show that neither of these genes are present, this means that the individual is unlikely to develop coeliac disease in the future.

How can coeliac disease be treated?

Coeliac disease can only be controlled by adhering to a lifelong gluten-free diet.

This means that any foods containing gluten should be avoided including (but not limited to) bread, pasta, cereals, biscuits, and cakes.

If you have been diagnosed with coeliac disease, it is especially important to check the labels on any food you buy, as many foods (particularly processed foods) include additives and flavourings that contain gluten.

Once a person with coeliac disease removes gluten from their diet, they will typically start to see a significant improvement in their health.

Gluten can also be found in some non-food products including cosmetics and certain medications.