Celiac disease

Celiac diseaseCeliac disease is an immune-mediated disease of the small intestine which occurs as a result of the consumption of gluten in genetically predisposed individuals. Celiac disease usually initially presents with diarrhoea in childhood years. It can also appear in adulthood and present with diarrhoea and crampy abdominal pain. Today it is still diagnosed by a biopsy of intestinal mucosa. Immunologic tests have an important diagnostic value by detecting disease-specific antibodies. The new diagnostic criteria, however, also take genetic analysis into consideration since celiac disease has a genetic component.

Why should you have your DNA analysed for predisposition to celiac disease?

Although it is an immune disorder, we can determine your predisposition for this disease by checking your genome. According to the European and USA estimates, 1 in 100 people have this disease. This means that celiac disease is one of the most common chronic diseases.

How is celiac disease prevented or treated?

The disease is managed with a strict diet. All gluten-containing wheat must be excluded from the food. However, care must be taken when consuming other processed foods as they often contain gluten. If you have gluten sensitivity, read always the product label. Food without gluten is marked "gluten-free"!

More detailed description about celiac disease

Celiac disease is an autoimmune disorder of the small intestine that occurs in genetically predisposed people, and is the result of the consumption of gluten. Gluten is a protein that is found in many cereals, especially in wheat, rye and barley. Symptoms of the disease include chronic diarrhoea and flatulence. The result of diarrhoea is poor absorption of food and failure to thrive. However, the disease can also develop in adulthood, when it causes not only intestinal symptoms, but also a number of other health problems.

The prevalence of the disease in Europe and the U.S. is now estimated to be 1 of 100 to 1 of 200 inhabitants. This means that celiac disease is one of the most prevalent chronic diseases in general. Celiac disease is not just a disease that occurs in children, but in different clinical forms affects people of all ages.

The disease is caused by the damaging effect of gluten, a protein that is found in a number of cereals, mainly wheat, rye and barley. Gluten triggers an immune response in the bowel, leading to inflammation of the intestinal mucous membrane and the resulting long-term diarrhoea.

Celiac disease most often begins with diarrhoea in childhood, resulting in stunted growth. The disease can also occur in adulthood, when usually extra intestinal signs of the disease occur. Inadequately treated celiac disease can cause complications with many other parts of body. The most common is anaemia due to a lack of iron, folic acid or vitamin B12. Another unpleasant problem is osteoporosis, which typically occurs with adults. There are also other problems connected with the disease, such as inflammation of the joints, enamel defect and inflammation of the skin. It may also affect the reproductive system. Puberty delays have been shown in girls and boys with untreated celiac disease, while there are also other frequent problems, particularly infertility, irregular menstruation and abortions. Liver is often impaired in elderly patients with celiac disease, but it can be treated with the proper diet. It has been known for a long time now that in patients with untreated celiac disease neurological complications are more prevalent, such as balance disorder and epileptic seizures. The most serious complication caused by the disease is undoubtedly the development of various malignancies, especially the small bowel malignant lymphoma.

Disease diagnosis

Today, the diagnosis is still based on the intestinal mucous membrane biopsy. However, immunological examinations also have an important role in setting the diagnosis, by establishing the presence of antibodies in the blood (AMA, EMA, t-TG). Common feature in all patients with the celiac disease is their genetic tendency for the development of the disease. Therefore, recent diagnostic criteria also include the use of genetic tests, mostly defining the presence of HLA-DQ2 or HLA-DQ8 serotype. HLA is short for “Human Leukocyte Antigen”, and the HLA genes are located at 6th chromosome. Genetic code for HLA-DQ2 or HLA-DQ8 is present in more than 30% of white population in Europe and USA. Presence of these alleles is not connected with celiac disease, but their absence is strongly associated with disease absence. Celiac disease patients that do not carry HLA-DQ2 or HLA-DQ8 are found extremely rare.

Genes have bigger influence than environment

Family research and research on twins have shown that there is a genetic tendency for development of the celiac disease. Based on these studies it has become apparent that the incidence of disease among family members and twins is too significant to explain the causes of the disease solely with environmental factors. Therefore genetic factors play an important role. More detailed genetic analyses have shown that the tendency for the development of the celiac disease includes several genes on different chromosomes. It is a complex genetic background, which includes in particular genes that are involved in the inflammatory response. Most studied so far have found the connection between the disease and HLA system.

Prevention

The patient must exclude all gluten-containing foods from their diet. The gluten-free diet should be life-long. This diet allows the mucosa and the villi of the small intestine to recover, and the body can absorb and use the nutrients and regain the lost weight. The diet, however, does not prevent the appearance of certain celiac disease-associated autoimmune diseases such as the autoimmune thyroiditis.

One should not eat cereals and food products made of wheat, rye, barley and oats. Celiac patients should not eat flour, semolina, bread, breadcrumbs, biscuits, pasta, noodles (containing wheat, barley or rye), cakes and similar foods. Patients must take great care regarding the ingredients of other food products as well for they may contain supplements of wheat origin (various emulsifiers, stabilizers and preservatives). Special gluten-free flour, gluten-free bread, pasta and other gluten-free products exist as a substitute for wheat flour. When shopping, one must necessarily look at the product labels to study all the ingredients. The product label should inform about the exact ingredients of the product. Identifying gluten-free products is nowadays easier due to the EU regulations that require manufacturers to declare the possible presence of gluten. In some products there is a possibility of gluten contamination during the production process (dried meat products, soya sauces, sweets, ice-cream, meat preparations and other processed foods). Thus, patients should not consume such type of food unless they are absolutely certain that they are gluten-free.

Gluten-free products can be bought in specialized grocery stores, in diet sections of the supermarkets partly also in pharmacies. The products for patients can easily be identified by a crossed-out ear of wheat logo on the package, a symbol that guarantees the absence of gluten.

Exclusion of all cereal based food products can result in a reduced intake of plant fibers. This can be avoided by regular consumption of fruits and vegetables. Patients should also consume enough vitamins, especially the B-complex vitamins, as well as foods containing calcium and iron.

Gluten-free food products allowed in the diet of celiac patients are: cereals (rice, corn, buckwheat, millets), potato, chestnut, vegetables, fruits, milk, eggs, meat, fish, honey, sugar, vegetable oils.

Therapy

The disease cannot be cured with medications. The only effective therapy is the gluten-free diet. Some patients have a resistant disease type, meaning that their condition does not improve on gluten-free diet alone. A reason for that may be that the disease has been present for so long that intestinal recovery is no longer possible. In this case, one may resort to medications such as corticosteroids and immunosuppressants.

Various experimental drugs are in the development phase but they are not expected to become available for general use in the near future. With the use of genetic engineering, minimally-immunogenic wheat types may be developed. In addition, by employing a combination of enzymes (propyl endopeptidase and glutamine-specific cysteine endopeptidase), gluten breakdown in duodenum could be facilitated. In this way, celiac patients would be able to consume gluten-containing food as well. Furthermore, it is being researched how to reduce the influence of gluten on the immune system by inhibiting zonulin, which is an intestinal signalling protein, connected with an altered intestinal wall permeability.

The aim of the treatment is to enable patients to shake off the burden of the gluten-free diet, but the mentioned treatment modalities are still in the trial phase. To be useful to patients, any new treatment option will have to satisfy the requirements of reliability, safety and efficacy; this, however, is not expected in the next few years. A strict gluten-free diet thus remains the core of prevention and therapy.