Celiac Disease: What Kind of Disease It Is, Symptoms and Diagnosis

Celiac disease is not a "wheat allergy": it is an autoimmune disease in which the immune system attacks the body's own tissues of the small intestine when gluten is ingested. Damage to the intestinal surface impairs the absorption of vitamins, minerals, and other nutrients. Below: the mechanism, forms, and diagnosis, with figures and caveats about the quality of evidence.

What celiac disease and gluten-sensitive enteropathy are

Celiac disease, also known as gluten-sensitive enteropathy (the old name is Gee-Herter-Heubner disease), is a genetically predisposed intolerance to gliadin and gluten, an autoimmune disease localized predominantly in the small intestine. The immune system mistakes fragments of gluten for a threat and damages the surface of the small intestine, so that nutrients stop being absorbed. Gluten is a protein of wheat, barley, and rye; oats do not contain gluten but can trigger a reaction if they are produced near these grains, and a small proportion of patients react even to pure oats.

Why celiac disease occurs

The exact cause is unknown; researchers point to a combination of genetics and environmental factors. More than 95% of patients carry HLA-DQ2 or HLA-DQ8 variants: such receptors bind gliadin proteins more strongly and activate T lymphocytes more readily. Carriage alone is not a disease: the predisposing gene is common, while by 2000 the diagnosis was made in approximately 0.5–1% of the population.

Prevalence in Western populations is 0.5–2%, in the UK at least 1 person in 100; some cases are undetected or attributed to irritable bowel syndrome. Registered cases are more common in women, and the disease can manifest at any age. The risk is higher with type 1 diabetes, autoimmune thyroid diseases, Down and Turner syndromes, and in first-degree relatives.

Typical and atypical forms of the disease

The classic form with severe malabsorption — diarrhea, wasting, anemia, developmental delay — is rare today. Mass serological screening followed by biopsy has shown that silent and subclinical variants occur about an order of magnitude more often than typical celiac disease. Intestinal symptoms are more common in children; in adults the picture is often blurred.

• intestinal — bloating, abdominal pain, chronic diarrhea or fatty, foul-smelling stool, constipation, nausea, lactose intolerance;
• general — fatigue, weight loss in adults and poor weight gain in children, delayed growth and puberty;
• extraintestinal — dermatitis herpetiformis, bone and joint pain, depression and anxiety, aphthous ulcers;
• neurological and reproductive — peripheral neuropathy, ataxia, infertility.

Atypical celiac disease in adults: what to look for

In the vast majority of patients, diarrhea and malabsorption symptoms are absent, but extraintestinal manifestations are detected: iron deficiency anemia, aphthous stomatitis, dermatitis herpetiformis, osteoporosis, short stature, delayed sexual development, infertility, type 1 diabetes. The disease may run a blurred course and be mistaken for another condition. Screening of patients with insulin-dependent diabetes revealed asymptomatic celiac disease in 6.4%.

How celiac disease is diagnosed

There is no routine screening: testing is offered when there are symptoms or an increased risk, and to first-degree relatives on the basis of kinship. The first step is serology. Antibodies to tissue transglutaminase (tTG): sensitivity 95–98%, specificity 94–95%. IgA endomysial antibodies are specific but difficult to perform. The final diagnosis is confirmed histologically: during upper endoscopy the physician examines the mucosa of the esophagus, stomach, and duodenum and takes a tissue sample. Serology without biopsy is not used as a basis for diagnosis.

Complications and when to see a doctor

Complications affect those who continue to eat gluten or have not yet received a diagnosis: osteoporosis, iron deficiency anemia, vitamin B12 or folate deficiency. Less commonly — certain cancers, including bowel cancer, and problems during pregnancy.

Celiac disease itself is not an emergency and is not a reason to call an ambulance. 103 or 112 — if signs of a life-threatening condition appear, such as symptoms of stroke or heart attack, or severe trauma.

People see a gastroenterologist for chronic diarrhea, weight loss, anemia of unknown origin, itching with a rash; first-degree relatives discuss testing even without complaints. This material is for reference and is not a recommendation: it does not replace a doctor's consultation.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer