CD, Gluten enteropathy, Gluten sensitive enteropathy
Celiac disease (CD) is a chronic intestinal autoimmune disease caused by intolerance to gluten, which are various proteins found in wheat and in other grains such as barley, and rye.
Upon exposure to ingested gluten, an abnormal immune response may lead to the production of several different autoantibodies that can affect a number of different organs. In the small bowel, this causes an inflammatory reaction (Pic. 1), which damages the mucosal lining of the intestine and may lead to structural changes, such as shortening of the villi and even flattening of the folds in the wall of the small intestine (Pic. 2). This affects the absorption of nutrients, frequently leading to anaemia (decreased amounts of hemoglobin in blood).
The disorder has a multifactorial etiology (many causative factors are involved in varying proportions) in which the triggering environmental factor, the gluten, and the main genetic factors, Human Leukocyte Antigen (cellular proteins that can trigger an immune system response) HLA-DQA1 and HLA-DQB1, are well known.
Diagnosis is typically made by a combination of blood antibody tests and intestinal biopsies, helped by specific genetic testing. Celiac disease diagnosis can be established by serological tests, searching for anti-tissue transglutaminase (anti-TG2) and anti-endomysium (EMA) auto-antibodies (which are both serological markers for an active gluten-sensitive enteropathy), but confirmation of the intestinal damage relies on the small bowel biopsy and histological analysis. Making the diagnosis is not always straightforward. Frequently, the autoantibodies in the blood are negative and many people have only minor intestinal changes with normal villi.
Celiac disease may present with typical symptoms such as diarrhea, steatorrhea (voluminous, fatty and foul-smelling stool), weight loss, and growth failure or non-typical symptoms not involving the gastrointestinal tract. The classic presentation of celiac disease is more common in young children, consisting primarily of gastrointestinal symptoms. In adults, the presentation of celiac disease is often more subtle and can be mistaken for irritable bowel syndrome. Some patients lack any evident gastrointestinal symptoms and instead present with nutritional deficiencies (most commonly iron deficiency) or extra-intestinal symptoms, or are asymptomatic.
A life-long gluten-free diet is the only available and effective therapy, which leads to normalization of histological and serological parameters and to complete remission of all clinical signs.
Fully developed symptoms such as malabsorption, steatorrhea and anemia are usually only seen in infants and young children. Adults more frequently present with atypic and less pronounced symptoms, commonly extraintestinal (affecting other systems than the gastrointestinal tract) or mimicking common issues such as dyspepsia (abdominal dyscomfort or pain) or irritable bowel syndrome.
The diarrhea that is characteristic of coeliac disease is (chronic) pale, voluminous, and abnormally malodorous. Abdominal pain and cramping, bloatedness with abdominal distension (thought to be due to fermentative production of bowel gas), and mouth ulcers may be present. As the bowel becomes more damaged, a degree of lactose intolerance (means the body cannot easily digest lactose, a type of natural sugar found in milk and dairy products) may develop.
Coeliac disease leads to an increased risk of both adenocarcinoma (a malignant tumour originating in glandular tissue) and lymphoma (a tumour composed of lymphocytes), termed enteropathy-associated T-cell lymphoma, or EATL, of the small bowel. This risk is also higher in first-degree relatives such as siblings, parents, and children. Whether or not a gluten-free diet brings this risk back to baseline is not clear.
Long-standing and untreated disease may lead to other complications, such as ulcerative jejunitis (ulcer formation of the small bowel) and stricturing (narrowing as a result of scarring with obstruction of the bowel).
The changes in the bowel make it less able to absorb nutrients, minerals, and the fat-soluble vitamins A, D, E, and K.
Malnutrition and its derived symptoms most commonly present in undiagnosed females with celiac disease. This symptom can directly compromise the potential and ability to conceive due to a negative energy balance and the decreased ability to maintain fat storage in afflicted females. Those with undiagnosed celiac disease and who do not follow a gluten-free diet may intensify unfavorable conditions for conception within the body and, more specifically, within the reproductive system.
Due to celiac disease, women have deficiency of folic acid, iron, zinc and selenium, which is neccassary for a healthy reproductive life. All of them are essential for hormone production, and with lower levels of hormones, the ability of ovulation is decreased. Without ovulation, it is not possible to concieve a child.
Also women with celiac disease may start their periiods later and have earlier menopause, which leads to shorter period of fertility.
Men also suffer from infertility stemming from undiagnosed celiac disease. Affected males show a phenomenon of tissue resistance (insensitivity) to androgens (especially testosterone), which are neccessary for sperm development. The increased levels of follicle-stimulating hormone (FSH) and prolactin, which control the levels of androgens and thus also the sperm production, may indicate an imbalance at hypothalamus-pituitary (the highest regulatory centers of endocrine functions) level. Hypogonadism (diminished functional activity of the gonads—the testes in males) is a known factor in male infertility and has been found in 7% of celiac males in one survey.
Depending on the extent of the celiac disease at the time of diagnosis and also extent of complications and diet complication, the prognosis may vary. However, the prognosis is generally regarded as good. People with celiac disease are at higher risk of mortality than the general population. Although people with celiac disease had an increased risk of gastrointestinal and lymphoproliferative malignancies compared with the general population, it has been shown that they are in a lower risk of breast or lung cancer. The presence of gastrointestinal malignancies is associated with a particularly poor prognosis among patients with celiac disease.