"Celiac disease (CD) is a genetic, autoimmune disorder that occurs in reaction to the ingestion of gluten. To develop celiac disease a person must inherit the genetic predisposition, be consuming gluten, and have the disease activated. Activation triggers may include stress, trauma (surgeries, etc.) and possibly viral infections. The reaction to gluten causes villous atrophy or flattening of the cells lining the small intestine, which can lead to malabsorption of nutrients and related health issues. There are over 200 identified symptoms of CD, which include those listed above as well as anemia, behavioral changes, stunted growth and infertility. Dermatitis herpetiformis is celiac disease that manifests as a skin rash. The rate of CD is higher among relatives of those who are diagnosed, but anyone with the genetic predisposition can develop celiac disease at any age. Currently it is estimated that about 1% of the population has celiac disease, although 83% of those people are still undiagnosed. While research continues to work towards pharmaceutical or other treatments, at this time the only treatment for celiac disease is to maintain a gluten-free diet for life."

"Non-Celiac Gluten Sensitivity (NCGS), also referred to as gluten sensitivity (GS) or non-celiac wheat sensitivity (NCWS), is not well defined. It is not an immunoglobulin E (IgE) (as with wheat allergy, see below) nor autoimmune reaction (as with CD, see above). NCGS may have an innate immune component, but this has not been firmly established. There are no tests or biomarkers to identify NCGS. Since NCGS is not well understood it is still not clear whether other components of gluten-containing grains may be involved in causing symptoms, at least in some cases. In order for gluten sensitivity to be diagnosed, it is first necessary to rule out CD, wheat allergy or other possible causes of symptoms. Then, if improvement is seen when following a gluten-free diet, gluten sensitivity may be diagnosed. Adherence to a gluten-free diet is the only treatment for NCGS at this time."

"Wheat allergy is an immune reaction to any of the hundreds of proteins in wheat. When a person has a wheat allergy, one type of white blood cells, called B-cells, send out immunoglobulin E (IgE) antibodies to “attack” the wheat. At the same time, local tissues in the body send out natural chemical messengers to alert the rest of the body that there is a problem. This reaction happens very fast (within minutes to a few hours) and can involve a range of symptoms from nausea, abdominal pain, itching, swelling of the lips and tongue, to trouble breathing, or anaphylaxis (a life-threatening reaction). A person with a wheat allergy must avoid eating any form of wheat, but does not have trouble tolerating gluten from non-wheat sources. (It is possible for a person to be both allergic to wheat and have CD or NCGS.) In the United States, wheat is one of the eight most common foods to which people are allergic. Children who are allergic to wheat may out-grow the allergy, but adults with an allergy to wheat usually have it for life. The only treatment is a wheat-free diet."

"In non-celiac gluten sensitivity (NCGS), a person has gastrointestinal symptoms from gluten exposure but does not have significant rise in tTG level (the blood test for CD) or any damage to the small intestine. NCGS is not believed to be triggered by a T- cell mediated immune response to gluten, as is the case with CD. In CD, gluten activates one’s immune system to attack the cells of the small intestine and cause damage. That is why tTG or other celiac-specific markers rise. 

"Often, it is not easy to distinguish between these two entities based on the clinical picture alone. Genetic testing, blood work and endoscopy might be needed. However, our group at BIDMC recently found that people who report symptoms with gluten exposure and who have negative blood markers, no family history of CD, no personal history of autoimmune diseases (such as type I diabetes), and no diarrhea associated with weight loss are extremely unlikely to have CD and do not need endoscopy. Visit Non-Celiac Gluten Sensitivity on www.celiacnow.org."

"Non-celiac gluten sensitivity (NCGS) does not cause visible damage of the small intestine in endoscopy. But occasionally, the biopsy may show some inflammatory cells only. The presence of normal villous architecture is the characteristic feature of NCGS, unlike in celiac disease."

"Current knowledge about NCGS is still very limited. So far, most research has failed to prove a common biology in both conditions. People with NCGS often have symptoms that may be more similar to Irritable Bowel Syndrome (IBS) than with CD but there is considerable overlap in symptoms. Some research has shown that patients with diarrhea-predominant Irritable Bowel Syndrome (IBS-D) may have gluten sensitivity. Also, according to guidelines, all patients with IBS-D should get screened for CD. The true relationship between CD, NCGS and IBS remains unknown. At this point, we believe that the risk of NCGS progressing to CD is very low. We await further studies of this issue."