The Role of Gluten in Coeliac Disease
Gluten is found in wheat, rye and barley and is made of 2 proteins Gliadin and Glutenin which are both conjoined to starch. People who suffer with Coeliac Disease are sensitive to these proteins, which is caused either by having a reaction to the Gluten when the enzyme Tissue transglutaminase (TG2 or tTG), modifies the protein and only partly converts it. Causing the immune system to create specific B-cell responses that result in Anti-transglutaminase antibodies (ATA). These react with the small bowel tissue which causes an inflammatory response, leading to the flattening of the small intestines, known as Villious Atrophy. This prevents the absorption of the fat-soluble vitamins A, D, E and K, and minerals from food. Because of the decreased bowel surface and reduced production of Lactase will result in being Lactose intolerant.
Another way in which people can suffer with Coeliac Disease is when the body produces Anti-gliadin antibodies (AGA) which are produced in response to the Gliadin protein in Gluten. Anti-gliadin antibodies (AGA) and Anti-transglutaminase antibodies (ATA) are both frequently found in people with Coeliac Disease. It is important to know which proteins have been found when tests are performed to detect Coeliac Disease.
The Anti-gliadin antibodies (AGA) is found in ~ 80% of people with Coeliac Disease [1] [2]. It is also found in people who are not enteropathic, when people do not have intestinal problems. A proportion of these may have neuropathies which will respond to a gluten free diet. This is referred to as gluten-sensitive idiopathic neuropathy [3].
If you have Anti-gliadin antibodies (AGA) which are measured for by ELISA or radio immunoassay blood tests [2]. A standard level should be 10 with an ideal value of 3 to be expected, levels of above 10 indicate Coeliac Disease with many people having in excess of 200. People who switch to a gluten free diet would expect a drop of antibodies and symptoms, however the half life of the AGA antibodies is typically 120 days. People with very high levels can take up to 2 years for the antibodies to return to the normal range.
references:
[1] ^ Volta U, Cassani F, De Franchis R, et al. (1984). “Antibodies to gliadin in adult coeliac disease and dermatitis herpetiformis”. Digestion 30 (4): 263-70. doi:10.1159/000199118. PMID 6391982.
[2] ^ Volta U, Lenzi M, Lazzari R, et al. (1985). “Antibodies to gliadin detected by immunofluorescence and a micro-ELISA method: markers of active childhood and adult coeliac disease”. Gut 26 (7): 667-71. doi:10.1136/gut.26.7.667. PMID 3894169.
[3] ^ Hadjivassiliou M, Gibson A, Davies-Jones GA, Lobo AJ, Stephenson TJ, Milford-Ward A (1996). “Does cryptic gluten sensitivity play a part in neurological illness?”. Lancet 347 (8998): 369-71. doi:10.1016/S0140-6736(96)90540-1. PMID 8598704.
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