Celiac disease is also known as non-tropical sprue or gluten induced enteropathy. It is an immune mediated enteropathy, triggered by a gluten containing cereal such as wheat, rye, and barley. This results in an inflammation of the upper small bowel, which improves when gluten is withdrawn from the diet; yet, one will relapse when gluten is introduced back into the diet.
Celiac disease commonly occurs in children, although the onset in adults is not rare. According to the Celiac Support Association, 1 in 141 people has celiac disease. Moreover, according to the National Health and Nutritional Examination Survey(NHANES), approximately 80% of people are not yet diagnosed with celiac disease.
Etiology: What exactly causes celiac disease?
Celiac disease is a unique intestinal disorder because of the environmental precipitant gluten is known for.
What is gluten?
Gluten is the entire protein content found in wheat, barley, and rye. Gluten is found in flour and it is the gluten that helps to prevent the crumbling of bread and other baked products. Gluten is used in almost all bakery products, due to its unique characteristics.
Gluten is made up of gliadin proteins. Due to the high content of glutamine and proline content in the gliadin protein, it is resistant to digestion by the pepsin and chymotrypsin enzymes. Pepsin and chymotrypsin enzymes are produced by your stomach and pancreas to aid in digestion of the proteins you eat. Therefore, gliadin will remain in your bowels triggering an immune response.
These gliadin peptides induce the epithelial cells to express interleukin 15, a pro-inflammatory cytokine. Interleukin 15 prompts the activation and proliferation of intra epithelial lymphocytes that are induced to express a natural killer cell marker known as NKGD2. These lymphocytes become cytotoxic (toxic to living cells) and kill the cells lining your small intestine.
In the lining of your intestines are special cells with a replicating property to produce new intestinal cells. These special cells are called crypt cells. The crypt cells increase its activity in celiac disease to replace the destroyed intestinal cells but are unable to keep pace with the loss of cells, resulting in a progressive reduction in the height of the villi. This is known as villous atrophy. In a normal person, the villi are about three to four times the height of the crypts (villus: crypt ratio of 3-4:1); In celiac disease, this ratio decreases progressively. In severe cases of celiac disease, the villi are completely wasted with a villus: crypt ratio of 0:1.
Celiac disease is also known to be associated with other immune diseases including type 1 diabetes, thyroiditis, and Sjogren’s syndrome.
How do you get celiac disease?
Celiac disease cannot be transmitted from someone else. It is something that you are born with. Although it has been documented that mostly females are affected by the disease, celiac disease is not gender or age specific. The exact cause that triggers celiac disease is not identified; however, the following are attributes a person must have to develop celiac disease.
- Genetic predisposition — Be born with the genes that makes you susceptible to celiac disease.
- The diet — You have to consume a diet containing gluten.
- Auto-antigen enzyme — Tissue transglutaminase.
- Production of pro-inflammatory cytokines — Interleukin 15 and especially interferons.
- It is an autoimmune disorder triggered by gluten containing cereals.
- It damages the absorptive surface of the small intestine, resulting in malabsorption.
- At present, there is no cure but celiac disease is managed by a gluten free diet.