Celiac disease is an autoimmune disease where the body has an immune response to gluten, a protein found in wheat products as well as in rye and barley. Celiac disease causes damage to the intestinal villi. This means that the hair-like lining of the intestines, which functions for absorption of nutrients, are flattened. This then leads to malabsorption. Celiac disease should not be confused with gluten sensitivity as this is not an autoimmune disease.
Screening for celiac disease is recommended for various individuals. Children older than 3 years of age and adults that experience any celiac symptoms should get tested. Those individuals with a direct family member (parents, sibling and even child) that has celiac disease should also strongly consider getting tested. If any other autoimmune disease is present such as autoimmune thyroid disease, type 1 diabetes, Downs Syndrome etc. then these individuals should also consider getting tested.
When someone suffers from celiac disease, a multitude of symptoms could be experienced. Some of the gastrointestinal symptoms include: abdominal pain, abdominal distension, blood in stool, flatulence and vomiting. Other symptoms include iron-deficiency anemia, fatigue, weight loss, easy bleeding, and joint pain. There are many more symptoms too which often makes it difficult to identify.
Screening – The First Test
The first test that is recommended to screen for celiac disease is the tissue Transglutaminase antibody test for IgA (anit-tTG-IgA). This is a simple blood test that is done and it is currently the most sensitive and specific test for screening for celiac disease. When someone goes for this test, it is important that they be on a gluten-containing diet – otherwise results may not be accurate. When gluten is eliminated from the diet completely then the antibody levels will go down.
There are a variety of other tests that can also be done to screen for celiac disease but these are not as specific or sensitive and some are not as easy to do or interpret as the anti-tTG-IgA test. These other tests include Quantitative Immunoglobulin A (IgA), Deaminated Gliadin Peptide (DGP IgA and IgG), Anti-Endomysial Antibodies (EMA) and Anti-Reticulin Antibody (ARA).
Quantitative Immunoglobulin A (IgA):
Some people may be deficient in immunoglobulin A (IgA). The dietitian may order the Quantitative Immunoglobulin A (IgA) test either before, after or with the anti-tTG-IgA test to determine whether or not an individual has an IgA deficiency. Having this deficiency can cause the anti-tTG-IgA test results to have a false negative (stating that you do not have celiac disease when in fact it is due to the deficiency in IgA). If there is a deficiency in IgA, then the IgG form of the antibody tTG test can be ordered.
Deaminated Gliadin Peptide (DGP):
This test can be useful in some individuals because if anti-tTG-IgA results come up as being negative for celiac disease, the results of this test can show up as positive. This is likely for children that are younger than 2 years of age.
For the individuals that have a low IgA, the DGP test is recommended along with the anti-tTG-IgG test because if the results of the DGP show positive then it will be necessary to monitor for celiac disease.
The EMA and ARA tests are not used very often. The EMA test is difficult to perform and the results are difficult to interpret. The ARA test results are not as accurate in screening for celiac as the anti-tTG-IgA test.
Diagnosis and Treatment
After receiving positive screening results, the diagnosis of celiac disease will be confirmed by undergoing a biopsy of the small intestine. Biopsies are very expensive and therefore many people do not go for a biopsy. If the anti-tTG-IgA test is found to be positive then many will eliminate gluten from the diet and show much improvement in symptoms. Treatment of celiac disease is the total elimination of gluten from the diet for life. It is important to make sure to read labels because gluten can be found in unexpected places.
Our celiac profile includes testing of: Anti-tissue transglutaminase IgA, Immunoglobulin A (IgA) and Deamidated Gliadin IgA to reliably diagnose or rule out celiac disease.
Please call us on 04 243 4166 to book your appointment for a celiac screening.