Coeliac disease is an autoimmune condition where the small intestine is chronically inflamed, and nutrients from food may not be absorbed properly. This is due to a permanent allergy to gluten in the diet (present in wheat, barley and rye), which activates an abnormal mucosal immune response. Coeliac disease is treated effectively in the majority of patients by sticking to a 100% gluten-free diet indefinitely. Although a gluten-free diet is an effective treatment in most patients, a significant minority develop persistent or recurrent symptoms. Difficulties sticking to such a diet have led to the development of non-dietary therapies, several of which are undergoing trials in human beings.
Coeliac disease is common: in the UK, 1 in 100 people have it, and numbers are rising. It is more common in individuals with a first-degree relative (ie a parent or sibling) with the condition and in people from or with close relatives from Ireland and Finland. Patients with conditions such as type 1 diabetes, microscopic colitis, autoimmune thyroid disease, Down’s syndrome and Turner syndrome are at a higher risk of having coeliac disease.
The diagnosis may be considered in people with iron deficiency anaemia, low folate or vitamin D, chronic fatigue, in pre-menopausal women with osteoporosis, or in those with recurrent abdominal bloating, loose stools, constipation or weight loss.
In patients with symptoms suggestive of coeliac disease a blood sample may be taken to look for special proteins or antibodies (anti-transglutaminase) that develop in patients with untreated coeliac disease. These are accurate in most cases (about 90%) but the “gold standard” diagnosis requires taking small samples (biopsies) from the small intestine at upper gi endoscopy and looking at these under a microscope to look for the characteristic signs of villous atrophy and an excess of inflammatory cells (lymphocytes). This test may be needed in patients who do respond to a gluten-free diet.
Coeliac disease is not to be confused with non-coeliac gluten sensitivity, which may present with similar symptoms but in the presence of normal blood tests and small intestine, and may improve on a gluten-free diet. Interestingly, a recent study found a subset of individuals with chronic fatigue syndrome may have sensitivity to wheat and related cereals in the absence of coeliac disease and may respond to dietary restrictions. There is still research to be done.
Advice on gluten free diet and what alternative foods can be eaten to maintain a balanced diet is best obtained from a state-registered dietician with experience in coeliac disease. Your GP (or a consultant gastroenterologist) will be able to make a referral for this advice if required.
For more information, please contact Dr Adam Harris.