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. 

Moderate quantities of oats, free of contamination with other gluten-containing grains, are usually tolerated but problems may depend on the type consumed. Upon exposure to 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 and may produce shortening of the villi lining the small intestine (villous atrophy; Pic. 1). This affects the absorption of nutrients, frequently leading to anaemia. 

The disorder has a multifactorial etiology 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 loci, 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. 

People may have severe symptoms and be investigated for years before a diagnosis is achieved. Increasingly, the diagnosis is being made in people without symptoms as a result of screening. 

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.


Gastrointestinal symptoms

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 and lymphoma 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). 

Malabsorption-related symptoms

The changes in the bowel make it less able to absorb nutrients, minerals, and the fat-soluble vitamins A, D, E, and K. 

  • The inability to absorb carbohydrates and fats may cause weight loss (or failure to thrive/stunted growth in children) and fatigue or lack of energy.
  • Anaemia may develop in several ways: iron malabsorption may cause iron deficiency anaemia, and folic acid and vitamin B12 malabsorption may give rise to megaloblastic anaemia (anemia caused by vitamin B12 deficiency).
  • Calcium and vitamin D malabsorption may cause osteopenia (decreased mineral content of the bone) or osteoporosis (bone weakening and risk of fragility fractures).
  • Selenium malabsorption in coeliac disease, combined with low selenium content in many gluten-free foods, confers a risk of selenium deficiency. 
  • Copper and zinc deficiencies have also been associated with coeliac disease. 
  • A small proportion have abnormal coagulation due to vitamin K deficiency and are slightly at risk for abnormal bleeding.


Coeliac disease has been linked with a number of conditions. In many cases, it is unclear whether the gluten-induced bowel disease is a causative factor or whether these conditions share a common predisposition.

  • IgA (immunoglobulin A) deficiency leads to an increased risk of infections.
  • Dermatitis herpetiformis (chronic blistering skin condition, characterised by blisters filled with a watery fluid; Pic. 2), an itchy cutaneous condition, has been linked to a transglutaminase enzyme in the skin, features small-bowel changes identical to those in coeliac disease, and may respond to gluten withdrawal even if no gastrointestinal symptoms are present.
  • Growth failure and/or pubertal delay in later childhood can occur even without obvious bowel symptoms or severe malnutrition. Evaluation of growth failure often includes coeliac screening. 
  • Pregnancy complications can occur in case of coeliac disease as an intercurrent disease in pregnancy, with significant complications including miscarriage, intrauterine growth restriction, low birthweight and preterm birth.
  • Hyposplenism (a small and underactive spleen) occurs in about a third of cases and may predispose to infection given the role of the spleen in protecting against bacteria. Abnormal liver function tests (randomly detected on blood tests) may be seen.
    It is also possible to have coeliac disease without any symptoms whatsoever. 

Associated diseases

  • autoimmune hepatitis
  • type I diabetes
  • thyroid diseases (Grave’s disease, Hashimoto’s thyroiditis)
  • dermatitis herpetiformis
  • alopecia areata (a condition in which hair is lost from some or all areas of the body)
  • gluten ataxia (a neurological condition that results from a reaction to the gluten protein)
  • Sjogren’s syndrome (a long-term autoimmune disease in which the moisture-producing glands of the body are affected)
  • systemic lupus erythematosus (an autoimmune disease in which the body's immune system mistakenly attacks healthy tissue in many parts of the body)
  • juvenile idiopathic arthritis (the most common chronic rheumatologic disease in children and is one of the most common chronic diseases of childhood )
  • dilated cardiomyopathy (a condition in which the heart becomes enlarged and cannot pump blood efficiently)
  • psoriasis (a long-lasting autoimmune disease which is characterized by patches of abnormal skin)
  • sarcoidosis (a disease involving abnormal collections of inflammatory cells that form lumps known as granulomas)
  • idiopathic thrombocytopenic purpura (type of thrombocytopenic purpura defined as isolated low platelet count )
  • thromboembolic phenomena (formation in a blood vessel of a clot (thrombus) that breaks loose and is carried by the blood stream to plug another vessel)
    microscopic colitis (an inflammation of the large intestine that causes persistent watery diarrhea)
  • anaemia
  • growth failure
  • delayed puberty



Coeliac disease is associated with an increased risk of malignancy, not only of intestinal lymphoma (a group of blood cell tumors that develop from lymphocytes located in intestine) but also of small intestinal adenocarcinoma (a type of cancerous tumor that can occur in several parts of the body) which is 82 times more common in patients with celiac disease than in the normal population. Enteropathy-associated T-cell lymphoma (EATL) is a very rare peripheral T-cell lymphoma which is mostly associated with celiac disease. 

Complications during pregnancy 

CD can induce malabsorption and deficiencies of micronutrients such as iron, folic acid and vitamin K, which are essential for organogenesis. The number of pregnancies ended in a miscarriage in celiac women has been observed to be almost twice that of healthy women, although the association in question is not statistically significant. In general, a larger number of complications have been observed in celiac women full term pregnancies compared to healthy women. In particular, the likelihood of having at least one complication during pregnancy has been estimated to be at least four times higher in celiac women than in healthy women. Moreover, a significant correlation has emerged for all the disorders under consideration (threatened abortion, gestational hypertension, placenta abruption, severe anaemia, uterine hyperkinesia, intrauterine growth restriction) and celiac disease. 

Risk factors

As for other autoimmune diseases, CD occurs more often in female than in male subjects with a gender ratio of about 2:1. Furthermore, gluten intolerance is more frequent in at-risk groups, such as first-degree relatives of patients as well as individuals with specific genetic syndromes (Down, Turner, Williams) or autoimmune diseases, mainly type 1 diabetes, thyroiditis (an inflammation of thyroid gland) and multiple sclerosis (a disease in which the insulating covers of nerve cells in the brain and spinal cord are damaged). 


At present, the only effective treatment is a lifelong gluten-free diet. No medication exists that will prevent damage or prevent the body from attacking the gut when gluten is present. Strict adherence to the diet allows the intestines to heal, leading to resolution of all symptoms in most cases and, depending on how soon the diet is begun, can also eliminate the heightened risk of osteoporosis and intestinal cancer and in some cases sterility. The diet can be cumbersome; failure to comply with the diet may cause relapse (a recurrence of a past condition).

Dietitian input is generally requested to ensure the person is aware which foods contain gluten, which foods are safe, and how to have a balanced diet despite the limitations. In many countries, gluten-free products are available on prescription and may be reimbursed by health insurance plans. Gluten-free products are usually more expensive and harder to find than common gluten-containing foods.

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 picture of tissue resistance to androgens (especially testosterone), which are neccessary for sperm development. The increases of follicle-stimulating hormone and prolactin, which are controling the levels of androgens thus also the sperm production, may indicate an imbalance at hypothalamus-pituitary 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.

In the past years, reports on the existence of a possible association between celiac disease and reproductive tract disorders have increased. As reproductive alterations are reversible, a timely diagnosis and the introduction of a gluten-free diet are of paramount importance. Thus, the use of early CD indicators, such as vitamin and/or iron deficiencies, andrologic or endocrinologic dysfunctions, should allow a prompt adoption of prevention and treatment strategies.

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