The small intestine is a vital organ where digestion and absorption of nutrients take place. The length of the small intestine is about 4 meters (3-4.5 meters), and 40% of it is formed by the duodenum and jejunum, and 60% by the small intestine called the ilium. The absorption surface of the small intestine is approximately 200-400 m2. This width in the area of the absorption surface is created by the folds of mucus lining the inner surface of the intestines and millions of projections called villi and microvilli that can be seen under the microscope. Villi are extensions that protrude into the cavity of the small intestine, while microvilli are about 1 micron in length and 0.1 µm in diameter and are extensions of intestinal cells called enterocytes (a micron is a thousandth of a millimeter) that can only be seen with a microscope. In the small intestine, absorption occurs in the villi.
What is celiac disease and how does it occur?
Celiac disease (Celiac disease, Celiac sprue, nontropical sprue), also known as gluten enteropathy, is a disease that causes disruption of digestion and absorption of nutrients in the intestines. People with celiac disease are sensitive to ‘gluten’, a protein also found in wheat, barley, rye and to a lesser extent oats. When these people are fed with gluten-containing foods, as a result of the immunological reactions that occur in the part called the mucosa, which is formed from the cells that cover the inner surface of the small intestine, destruction occurs in the absorbent cells in this region (Immunological reaction = a kind of inflammatory reaction created by the body’s immune system). Since the digestion and absorption of nutrients necessary for the body will be impaired after this destruction, diarrhea and a deficiency of these substances in the body over time begin. For this reason, Celiac disease is classified between malabsorption and intestinal diseases. When people with celiac disease are fed a gluten-free diet, the damage to their intestines improves, but if they start consuming gluten-containing foods again, the symptoms of the disease reappear.
Celiac disease is a genetic disease, the genes that cause this disease can be passed on in families. Up to 10% of celiac patients have other family members with celiac disease. Surgical interventions, pregnancy, childbirth, some viral infections and severe mental distress may cause the disease to occur. It is less common in blacks and people of Asian descent. Although it can occur at any age, it is more common in children aged 8-12 months and between the ages of 30-40.
The true incidence of celiac disease is unknown. The increasing frequency of the disease and the widespread use of diagnostic tests may be responsible for the fact that the disease is more common than before. The disease is most common in people living in western Europe and North America. One out of every 300 people living in these areas has celiac disease. The incidence of celiac disease across the United States is around 1/3000. However, serological studies on blood in the blood bank suggest that this disease may be found in one out of every 300 people.
What is the cause of celiac disease?
Celiac disease occurs as a result of the combination of environmental (gluten) and genetic factors that trigger the immunological response in the body. In other words, contact with gluten, which is both a genetic predisposition and an environmental factor, is necessary for the formation of celiac disease.
Immunological reactions:
The interaction of ‘gliadin’, the active ingredient of ‘gluten’, a substance found in wheat, barley, oats and rye, with the absorbent cells lining the inner surface of the small intestine, plays a role in the formation of celiac disease. It is one of the most important mechanisms. When a person with celiac disease is fed with a food containing gluten (gliadin), as a result of the immune system accepting this substance as a foreign substance (a type of allergy), the body’s immune system begins to produce some substances called antibodies against this substance (anti-gliadin antibodies). as). Since the immunologic reaction that occurs as a result of the encounter of these antibodies with gliadin is mainly in the small intestine mucosa, damage occurs in the small intestine mucosa resulting in malabsorption after this reaction.
People with celiac disease find two other types of antibodies in their blood besides the anti-gliadin antibody. Unlike anti-gliadin antibodies, these antibodies are antibodies formed against the person’s own tissues. One of them is ‘anti-endomysial antibodies’, which are formed against a substance in the structure of absorbent cells lining the inner surface of the small intestine, and the other is ‘anti-transglutaminase antibodies’, which are formed against an enzyme in the cell. The presence of these antibodies shows that autoimmunity plays a role in the formation of celiac disease (Autoimmunity: The immune system in the body tries to damage or destroy the formations in the body’s own structure – a kind of self-recognition defect).
What are the signs and symptoms of celiac disease?
Celiac disease manifests itself with different symptoms in children and adults. Developmental and growth retardation in children may be an early sign of celiac disease. Abdominal pain, nausea, vomiting, diarrhea, moodiness, behavioral disorders and failure in school are other symptoms that can be seen. It can take years for symptoms to appear and become severe. Generally, there is a partial decrease in the severity of the symptoms during adolescence.
Celiac disease usually occurs in adults around the age of 30-40, although it can also be seen in older ages. Diarrhea, abdominal gas and discomfort, abdominal pain, inability to gain weight despite a good appetite, or weight loss and fatigue are the main findings of celiac disease that occurs in adulthood, especially after the intake of fatty foods. Some celiac patients may have no symptoms other than intermittent diarrhea and indigestion for years. Menstrual disorders and inability to get pregnant in women, and decreased sexual power in men are other symptoms that can be seen rarely in celiac disease.
When celiac disease is not treated, deficiency of vitamins, minerals and other nutrients in the body occurs over time due to malabsorption in the small intestines. Among these, anemia (anemia), which can be of varying severity as a result of especially iron, folic acid and vitamin B12 deficiency, is one of the most common findings. In addition, as a result of impaired absorption of vitamin D and calcium, calcium levels decrease, osteoporosis and fractures, visual disorders and skin problems due to vitamin A deficiency, nervous system problems such as balance disorder and sensation defects due to deficiency of vitamin B derivatives, coagulation disorders due to vitamin K deficiency. and bleeding, muscle weakness due to deficiency of substances such as sodium, potassium and magnesium, leg edema due to protein (albumin and other proteins) deficiency and weakening of the immune system are other findings that may occur as a result of malabsorption in the intestines. Another discomfort that can be seen in celiac disease is a skin disease called dermatitis herpetiformis, which has a similar appearance to chickenpox, mostly presenting with itchy, rash and blistering lesions on the back, lower and upper extremities and buttocks. In addition, some rheumatic diseases, thyroid gland and adrenal gland diseases can also be found together with celiac disease.
How is celiac disease diagnosed?
When celiac disease is suspected, your doctor will ask you for some blood and stool tests after a thorough physical examination. In addition to measuring the blood levels of certain substances that may be deficient in this disease, such as calcium, magnesium, potassium, protein (albumin, immune globulins and coagulation factors), cholesterol, vitamin B12, vitamin A, folic acid and iron, performing a complete blood count and controlling inflammation markers. Some serological tests used in the diagnosis of celiac disease also need to be done. Anti-endomysial, anti-transglutaminase, anti-gliadin, and anti-reticulin antibodies are currently serological tests that are helpful in diagnosing celiac disease. The values of these serological tests in the diagnosis of the disease are high (55-95%). These tests may be false-negative in individuals with IgA deficiency.
Another examination that must be done in the diagnosis of celiac disease is to take a tissue sample from the small intestine mucosa with the help of an endoscope. The intervention for this procedure is not different from normal gastroscopy (See Endoscopy). It is also possible to see structural changes in the small intestine mucosa during endoscopy. After the tissue sample is stained with special methods, it is examined under a microscope to see the findings that may belong to this disease, and it is absolutely necessary for both the definitive diagnosis of celiac disease and the differentiation of other diseases such as lymphoma that may be confused with this disease.
Other methods that can be used in diagnosis are small bowel film with barium and imaging of the small intestine with capsule endoscopy or enteroscopy. Especially in patients with significant weight loss, abdominal pain, anemia, night sweats and bleeding, one or more of these examinations may need to be performed and other imaging methods such as computed tomography of the abdomen may be required when necessary.
When and how should celiac disease be treated?
Celiac disease can lead to serious problems if not diagnosed early. Those with complaints similar to the findings described above and/or those with a family history of celiac disease should consult a gastroenterologist. Since celiac disease shows familial transmission, it would be appropriate to examine the relatives of the patients at least with serological tests. Up to 10% of those with celiac disease can also have the same disease in their mother, father, sibling or children. Women with severe anemia during pregnancy should be investigated for celiac disease.
The basis of treatment in celiac disease is a strict gluten-free diet. For this purpose, foodstuffs made using gluten-containing grain products (wheat, barley and rye) should definitely not be eaten. Oats should also not be eaten, at least in the early stages of the disease, as they may contain wheat particles. Products made from rice, corn, potato and soy flour are edible. Instead of regular flour, rice flour or corn flour and pastries made from them should be preferred. Corn syrup sauce etc. It can be used as a thickener in production.
It is okay to eat fruit, vegetables, eggs and meat products, but wheat flour should not be used in the preparation of sauces. Alcoholic beverages and fruit juices can be drunk provided that they are not overdone. Small amounts of beer and whiskey may be tolerated, but should not be drunk if it triggers complaints. Following a gluten-free diet can be more expensive, difficult, and tedious than a regular diet. For this reason, it is not recommended to apply such a diet without a definitive diagnosis.
Today, various food products prepared for celiac patients can be easily obtained from large markets. The labels of the foods taken should be read carefully and should not be given to a celiac patient without investigating whether it contains a gluten-containing food item. Gluten can be found in many products (salad dressings, instant puddings, etc.) that are sold in the market and that are thought to be gluten-free. This is especially important since a celiac patient following a strict diet may encounter gluten again one day, which can lead to serious situations. Since these patients may also have lactase deficiency (lactose intolerance), it should be recommended not to take milk and dairy foods initially.
Symptoms begin to decrease days after starting a gluten-free diet. Although the symptoms disappear completely, it may take as long as 2 years for the intestinal mucosa to heal completely, but recovery in the intestinal mucosa usually takes place within 3-6 months.
There is no drug treatment for celiac disease. Corticosteroid therapy may be tried in patients who do not respond to a gluten-free diet. Patients who follow a strict gluten-free diet generally have a good course. In untreated patients, the above-described findings will continue due to the continuation of intestinal malabsorption. In cases that do not respond to treatment, other diseases of the small intestine such as lymphoma should be investigated. A serious disease that can occur in the long term in untreated cases is a type of small bowel cancer called Non-Hodgkin lymphoma (NHL). The incidence of NHL in patients with celiac disease is three times higher than in normal individuals. Transformation into cancer can be prevented in cases where a strict diet is applied.
