Coeliac disease is caused by permanent gluten intolerance. Gluten is a storage protein found in cereal grains; it makes dough sticky. For a patient with coeliac disease, gluten from wheat (called gliadin), gluten from barley (hordein), rye (sekalin) and oat (avenin) are harmful. Coeliac disease is a lifelong disease; it can appear at any age – from toddler to very old age.
Basis of Coeliac Disease
The basis of coeliac disease is autoimmune inflammation of small intestine mucosa triggered by gluten in food. This inflammation leads to thinning (atrophy) of the small intestine mucosa and it is connected to small intestine dysfunction, i.e. nutrient, mineral and vitamin malabsorption, and compromised intestinal barrier and immunity. Also the spectrum of coeliac symptoms is very varied: the typical coeliac disease in early childhood manifests itself by emergence of diarrhoea at the time gluten is being introduced into the child’s diet.
In older children and adults the symptoms of coeliac disease are often atypical, there is no diarrhoea, but there are other symptoms resulting from nutrition malabsorption in the small intestine (weight loss, growth retardation in children, chronic fatigue, several kinds of digestive issues – bloating, loss of appetite, abdominal cramping, even constipation, also iron deficiency and anaemia, osteoporosis…) or symptoms connected to compromised immune function of the small intestine (so called autoimmune diseases: e.g. thyroid disease, diabetes mellitus type 1, dysfunction of other endocrine glands, skin and mucosal diseases, rheumatic, bone and nerve diseases, etc.).
Causes of Coeliac Disease
Coeliac disease is genetically linked. The main genetic risk factor is the presence of the gene HLA DQ2 or HLA DQ8. These are the genes encoding the so called class II HLA antigens (HLA stands for Human Leukocyte Antigen, which are protein structures on the surface of human white blood cells, which take part in immunity, in recognition of extraneous substances in the body). And it is the HLA DQ2 and HLA DQ8 subtype which is a risk factor for coeliac disease development. At the present time, it is possible to test for the genetic risk of coeliac disease; however, the presence of the stated risk genes does not automatically give the diagnosis of coeliac disease. The given risk genes are actually very common in the European population and it is estimated that only 2-3 % of the gene bearers contract coeliac disease. For the coeliac disease to develop, consumption of gluten is necessary as well as the presence of other triggering factors (for instance the absence of breast-feeding, infection, stress).
Coeliac Disease Diagnosis
Diagnosis of coeliac disease is confirmed by the presence of both specific coeliac autoantibodies (antibodies against tissue transglutaminase, antibodies against endomysium, antibodies against deamidated gliadin peptides) in the patient’s blood and small intestine mucosa damage (so called villous atrophy), when the small intestine sample is obtained though biopsy most often performed during a gastroscopic examination. Both diagnostic procedures, i.e. test for autoantibodies in blood and small intestine biopsy, must be performed at the time the patient still consumes gluten. Otherwise the result can be false-negative. With children, a diagnostic approach omitting the small intestine biopsy has been used, if the autoantibodies (antibodies against tissue transglutaminase) are increased 10× over the upper normal limit and if there is a proven genetic risk. The number of coeliac patients has been rising in the recent years, which is certainly caused by better medical and social knowledge of coeliac disease and better diagnostic possibilities. Above that, however, there is also a general trend of increase in coeliac disease (similarly to other autoimmune diseases).
Possible Treatment of Coeliac Disease
The only possible treatment of coeliac disease is lifelong gluten-free diet enriched with vitamins, minerals and dietary fibre (naturally gluten-free whole-grain food). Patients with coeliac disease are under lifelong medical supervision aimed not only to control the symptoms, check adherence to the gluten-free diet, but also to detect potential vitamin and mineral deficit or associated illnesses. Screening (examination) is recommended for first degree relatives (i.e. parents, siblings and children of the coeliac patient), for individuals with suspicious symptoms and ailments including autoimmune diseases, which often accompany coeliac disease.