Celiac disease (synonyms: celiac disease; coeliac disease; indigenous sprue; gluten allergy; gluten-induced enteropathy; gluten-sensitive enteropathy; gluten intolerance; Heubner-Herter disease; intestinal infantilism; nontropical sprue; sprue, indigenous; ICD-10 K90. 0: celiac disease) is a chronic disease of the mucosa of the small intestine (small bowel mucosa; enteropathy) due to hypersensitivity to the cereal protein gluten* in genetically predisposed individuals. Celiac disease is an immunologically determined systemic/autoimmune disease. Special forms of celiac disease:
- Atypical celiac disease: extraintestinal symptoms (outside the intestinal system) are prominent. Celiac serology is positive. Few changes can be detected in the mucosa of the small intestine. No signs of malabsorption are present.
- Potential celiac disease: transglutaminase TG2-IgA and EMA-IgA titers (endomysium IgA titers) increased, with concomitant normal villous structure (type 0 or 1 according to Marsh) in at least 5 duodenal biopsy samples/tissue collection from the duodenum (bulb and pars descendens).
- Silent celiac disease: when positive antibody titers, a positive HLA constellation (see below laboratory diagnostics) and histological changes in the small intestine with absent clinical symptoms are present.
- Latent celiac disease: when a predisposing HLA status is present. Symptoms and antibody abnormalities may be absent.
Refractory celiac disease is said to occur when clinical and histological improvement is not achieved despite a strict gluten-free diet (GFD) for 12 months, after the diagnosis of celiac disease has been confirmed. So far only described in adult patients.Refractory celiac disease type I has an autoimmune character and type II a prelymphoma character (for further details see below under “Course and prognosis”). Because of the wide spectrum of intra- and extraintestinal manifestations (inside and outside the intestinal system), celiac disease is considered the chameleon of diseases and is still frequently overlooked. The diagnostic latency (time between the onset of first symptoms and the definitive diagnosis of the disease) is about 4 years! Sex ratio: Women are more frequently affected than men. Frequency peak: the disease occurs in infancy/primarily school age and in the 4th decade of life. At the time of diagnosis, women are on average between 40 and 45 years old; in men there are two age peaks – between 10 and 15 and between 35 and 40 years. Note: Individuals identified by screening may be completely asymptomatic despite marked villous atrophy! The prevalence (disease incidence) is 0.5-1% (in Germany); 0.3-3% (population studies). In Europe and North America, the prevalence is 1-2 %. In Africa and Asia, the disease is poorly known. In a Swedish study, more than 10,000 sixth-grade (12-year-old) children were screened for celiac disease using serological markers: 2.7% of the children showed positive serological findings, and the diagnosis could be confirmed histologically in 2.1%. The incidence (frequency of new cases) of celiac disease based on prospective screening studies is highest between the ages of 2 and 5 years.The cumulative incidence of refractory celiac disease is approximately 1.5%. Course and prognosis:If untreated, the disease leads to weight loss, until cachexia (emaciation; severe emaciation). In children, untreated celiac disease usually leads to a deficiency of vitamins and trace elements as well as iron deficiency anemia (anemia due to iron deficiency). This has a negative effect on growth and bone quality.Under a strict gluten-free diet (GFD), the symptoms usually improve within a few weeks. In contrast, the mucosa of the small intestine (small intestinal mucosa) regenerates within months and in individual cases within years. Tests for celiac disease-specific autoantibodies are negative. In rare cases, despite a strict gluten-free diet, the patient continues to suffer from a malabsorption syndrome with persistence (“persistence”) of the celiac-typical intestinal (“intestinal-related”) villous atrophy. If this is refractory celiac disease type I, the patient is usually treated immunosuppressively (“suppressing the normal function of the immune system“) if symptoms are present. In the presence of refractory celiac disease type II, there is an increased risk of developing enteropathy-associated T-cell lymphoma (ETZL).In these cases, extensive further diagnostics (bone marrow puncture, if necessary) are required. The lethality (mortality in relation to the total number of patients with the disease) of patients with celiac disease is increased. Based on data from ESPRESSO (“Epidemiology Strengthened by histoPathology Reports in Sweden”) with the Swedish mortality registers, it was found that the mortality (death rate) of 9.7 deaths per 1,000 person-years was significantly higher than in a comparison group of 246,426 Swedes of the same age and sex, where there were 8.6 deaths per 1,000 person-years. Comorbidities: The disease is associated with an increased risk of non-Hodgkin’s lymphoma (a cancer of the lymph nodes), lymphoma of the small intestine, and carcinoma of the gastrointestinal tract. Celiac patients are 2.5 times more likely to develop neuropathy (a collective term for many diseases of the peripheral nervous system). The highest risk for this diagnosis was in the first year after celiac disease was diagnosed.Another comorbidity is epilepsy (seizure disorder; HR 1.42 in children and 1.58 in adolescents (age < 20 years)). * Gluten (storage proteins of wheat) is also called gluten because it is crucial for the baking ability of wheat flours and improves the baking properties. Gluten accounts for about 80% of the total protein in wheat and consists of several fractions, including the proteins gliadin and glutenin.