What is a coeliac screen?

An overview

IgA antibodies to one or more antigens are indicative of undiagnosed coeliac disease. The preferred celiac disease test currently is IgA anti-tissue transglutaminase antibody. IgA anti-endomysial antibodies are then evaluated in all clinical specimens. There is a strong association between the two.

The extensive use of certain tests has made it clear that celiac disease affects people of all ages, including the elderly, and that its symptoms might vary. Coeliac disease is brought on by an immunological reaction to tissue transglutaminase or its by-products.

 The majority of uncontrolled coeliacs will have endomysial and IgA anti-tTg antibodies. Prior to anti-endomysial and occasionally before observable symptoms, IgA anti-tTg is more common. IgA anti-tTg typically vanishes following IgA anti-endomysial on a gluten-free diet. Return of antibody positive is frequently correlated with recurrence or poor adherence to a gluten-free diet.

 Keep in mind that IgA deficiency is frequently linked to celiac disease. In all individuals with presumed celiac disease, IgA levels are measured. IgG anti-tTg and IgG anti-endomysial antibodies are evaluated in IgA-deficient people with possible celiac disease.

The detection of IgG antibodies is normally required in order to identify IgA deficiency, which is typically detected by the IgA anti-TTg test.

Anti-reticulin autoantibodies are rarely encountered during routine autoantibody screening, and they may indicate celiac disease. In such circumstances, IgA anti-TTg will be examined in the serum.

 IgA anti-TTg and endomysial antibody-positive samples almost definitely come from celiac disease or dermatitis herpetiformis individuals. IgA anti-TTg positivity alone in samples may be an indicator of celiac disease progression. The most frequent factor contributing to "false positive" IgA anti-tTg results is elevated total IgA linked to liver cirrhosis. 

What is coeliac disease?

Coeliac disease is an autoimmune disorder in which an immunological response to Gluten occurs, a protein found in wheat, barley and rye.

Eating gluten sets off an immunological reaction in your small bowel if you have celiac disease. With time, this response wears down the membrane of your small intestine and prevents some nutrients from being absorbed (malabsorption).

Intestinal damage frequently results in diarrhoea, abdominal pain, exhaustion, weight loss, cramping, and anaemia and can have catastrophic consequences.

A strict gluten-free diet can help control symptoms and encourage intestinal recovery.

Causes of celiac disease

The exact aetiology of celiac disease is unknown. However, it may be influenced by your genetics, eating gluten-containing foods, and other factors. Methods used when feeding babies, gastrointestinal illnesses, and gut flora may also be involved. Celiac disease can occasionally become aggressive following surgery, pregnancy, childbirth, turner syndrome, autoimmune thyroid disease, viral infection, or significant mental stress.

The minuscule, hair-like protrusion (villi) that cover the small intestine are damaged when the body's immune system reacts badly to gluten in the diet. Villi are organs that take up vitamins, minerals, and other nutrients from food. Regardless of how much you consume, damaged villi prevent you from absorbing sufficient minerals.

Screening tests to diagnose coeliac disease

1.     tTG-IgA Tests and total IGA measurement

The best technique to screen for celiac disease in most adolescents and adults is using the Tissue Transglutaminase IgA antibody (tTG-IgA), together with an IgA antibody to ensure the patient produces enough of this antibody to make the suspected coeliac disease screening reliable. Some factors can suggest coeliac disease.

Deamidated gliadin IgA and IgG antibodies should also be included for infants and young children (about 2 years of age or younger).

For the accuracy of a simple blood test for celiac disease, you must follow a gluten-containing diet. In over 93% of celiac disease patients who consume gluten, the tTG-IgA test will be positive.

This is a reference to the test's sensitivity, which assesses how effectively it detects individuals with the condition. Approximately 96% of normal persons lacking celiac disease will have the same test results and bring it back negative.

Intestinal biopsy is the only means to diagnose celiac disease due to the possibility of misleading antibody test findings, while other antibody tests are possible to double-check for either false positives or false negatives.

2. IgA Endomysial antibody (EMA)

Although it is less sensitive than the tTG-IgA test, the EMA test has a specificity of about 100%, ranking it the most accurate test for celiac disease. Approximately 5–10% of celiac disease patients do not get a positive EMA result.

In comparison to tTG-IgA, it is likewise quite costly and demands the use of the person or primate amniotic sac. It is typically saved for individuals with challenging diagnoses. This test for coeliac disease can confirm the diagnosis.

3. Total Serum IgA

The purpose of this test is to detect IgA deficiency, a condition linked to celiac disease that can result in a false-negative tTG-IgA or EMA result. Your healthcare professional may request a tTG-IgG test if you have an IgA deficiency.

4. IgG deamidated gliadin peptide (DGP)

Those with IgA deficiency might utilize this test to further check for celiac disease. IgA deficiency in a patient may be a sign of various conditions, including giardiasis, SIBO, or common variable immunodeficiency that can lead to villus shrinkage.

Negative findings from an antibody test are conceivable in celiac disease patients. However, this is quite uncommon. If your tests came back negative, but you still have symptoms, contact your doctor and get expert advice for other tests.

5. Video capsule endoscopy (VCE)

VCE has a sensitivity of 89% and a specificity of 95% for diagnosing celiac disease. In comparison to routine upper endoscopy, this testing procedure is more effective at detecting morphological atrophies. The VCE is helpful in identifying celiac disease-related problems.

6. Intestinal fatty acid binding protein (I-FABP): 

This intracellular protein, which may be a sign of accidental gluten consumption, is released into the bloodstream when cellular problems happen.

7. Radiology for diagnosis of coeliac disease:

Some radiographic abnormalities, such as small-bowel dilatation, wall thickening, vascular alterations, and others, may point to the existence of celiac disease.

View the Welzo store for other health tests.

Read the 7 ways to tell if you have a food intolerance and who should use a gluten intolerance test.