What is Celiac Disease?
Celiac Disease is a common health disorder affecting more people than autism, breast cancer or Type 1 diabetes, but is greatly underdiagnosed.1 One person in a hundred is estimated to have celiac disease, but less than 5% of these people are being diagnosed. The other 95% are being harmed on a daily basis by eating common food like bread and pizza.
Celiac Disease is serious and the personal cost can be great. If left untreated, Celiac Disease can cause health problems ranging from inconvenience to debilitation and even death. It can affect work and relationships. The good news is that many health problems can be avoided by early diagnosis and eating a gluten-free diet.
The Name: Celiac Disease
"Celiac Disease" was the name given to this disorder because it was thought to primarily cause digestive symptoms. "Celiac" means bowel. Other names for celiac disease are Gluten Sensitive Enteropathy, Celiac-Sprue, and Non-Tropical Sprue.
The term, Celiac Disease, is used worldwide. Medical coding systems use it for billing purposes and as a tracking tool. The International Classification of Diseases (ICD-9-CM) code for Celiac Disease is "579.0 celiac disease." This is the code your doctor will use for your medical records.
Celiac Disease Explained
Celiac Disease is a common, inherited lifelong sensitivity to gluten, a protein in the grains of wheat, barley, rye, and oats. When activated by gluten, it becomes a digestive disorder that results in malabsorption of food nutrients with or without digestive symptoms like pain, bloating, diarrhea or constipation.
Active Celiac Disease involves a specific auto-immune response in the small intestine that inflames and damages the vital tissues of the lining. Resulting health problems are called multi-systemic because they may involve any body system. Symptoms may be few and mild or mind boggling in number and severity.
Figure 1.1 Small intestine in gray.2 Image is courtesy of the National Institutes of Health
Celiac Disease is a complex health disorder that has six characteristics:
- Genetic - runs in families,
- Chronic - cannot go away,
- Digestive - inflames and damages our small bowel,
- Autoimmune - produces self-destructive antibodies,
- Malabsorptive - interferes with nutrient absorption, and
- Multi-systemic - may harm any part of our body.3
People who have inherited susceptibility genes for Celiac Disease have the "potential" to develop "active" Celiac Disease. Potential means there can be no response without first eating food that is made with wheat, barley, rye, or oats. The gluten protein precipitates development of symptoms.
Once developed, active Celiac Disease is self-perpetuating and progressive as long as we continue to eat gluten. Damage stops when we stop eating gluten-containing food. However, we will always be susceptible to future harm from gluten because it is part of our genetic make-up. ((Murray, J., "The widening spectrum of celiac disease." American Journal of Clinical Nutrition. Mar 1999;69(3):354-365.))
All health problems in Celiac Disease begin when gluten contacts the surface of our small intestinal lining. Harm arises from interaction with partially digested segments of this protein called peptide fractions. These peptide fractions, also called prolamines, are 'gliadin' in wheat, 'hordein' in barley, 'secalin' in rye, and 'avenin' in oats. Research studying antibodies in children at diagnosis found that avenin antibodies follow the same pattern as gliadin antibodies but the magnitude was slightly lower. ((Hollen E, Hogberg L, Stenhammar L, Faith-Magnusson K, Magnusson KE. "Antibodies to oat prolamines (avenins) in children with celiac disease." Scandanavian Journal of Gastroenterology. 2003;7:742-746.))
Celiac Disease produces a destructive, auto-immune response in our small intestine at the site where gluten is being digested. Once the immune reaction is triggered, inflammation and damage occurs. Inflammation causes intestinal swelling and disorder, resulting in progressive loss of the natural folding of the lining and shape of the the intestine. A misshapen bowel can twist on itself or telescope one section into another. Either condition would require emergency surgery.
Damage occurs to the villi and crypts in varying degrees that interferes with nutrient absorption. Villi are minute structures that have the function of absorbing nutrients from the food we eat. They are multitudinous projections on our intestinal surface that wave in the liquid mix of nutrients passing through them. Crypts are valley-like formations between villi. Progressive inflammation leads to collapse of villi and thickening of the crypts, resulting in loss of function to absorb nutrients. ((Murray, J., "The widening spectrum of celiac disease." American Journal of Clinical Nutrition. Mar 1999;69(3):354-365.)) Read more...Digestion Guide.
Figure 1.2 Close-up illustration of a small section of the small intestine with flap cut away to reveal inner wall. The inset shows the microscopic finger-like structures, called villi, on the inner surface of the small intestine. ((“Celiac Disease.” National Digestive Diseases Information Clearinghouse, 1998. Retrieved from http://digestive.niddk.nih.gov.)) Image is courtesy of the National Institutes of Health.
Eventually, our intestinal surface can become flattened, losing both its folding and its villous structures. Its capacity can diminish from the size of a tennis court to that of a table top. ((“Celiac Disease.” National Digestive Diseases Information Clearinghouse, 1998. Retrieved from http://digestive.niddk.nih.gov.))
Loss of absorption results in malnutrition because damaged villi cannot properly finish digestion, absorb or transfer the full amounts of nutrients into our bloodstream as required for health. If we become deficient in one or more nutrients (malnutrition), our bodies cannot work well and problems develop. Malabsorption causes malnutrition, malfunction, and poor health.
Any part of our body can develop problems either from the effects of malnutrition or from toxic gluten peptides that abnormally enter our bloodstream. Once in our bloodstream, toxic peptides can directly harm any of our body tissues, causing disorders such as non-alcoholic fatty liver disease and arthritis. Complications can be serious, disabling, or deadly such as cancer and hardening of the arteries, which can lead to stroke or heart attack.
How Active Celiac Disease Develops
Health problems cannot begin until we actually eat gluten and become sensitized. For example, infants do not develop problems until they are introduced to food that contains gluten, such as a teething biscuit or baby cereal made of wheat, barley, rye, oats, or mixed grains. Or, they may themselves find a piece of pretzel inadvertantly dropped on the floor. Unfortunately, our society eats gluten in large quantities so that the risk of developing health problems can be great.
The process that leads to active Celiac Disease is not fully known but is under intense investigation. The onset of symptoms requires both genes and a trigger. The mechanism involves antibody production and increased intestinal permeability of the small intestinal lining, "leaky gut syndrome."
Celiac Disease affects one in about 100 persons of the general population, an epidemic proportion.But, if one member of a family has Celiac Disease, the odds are 1 in 10 that other close family members (parents, children, and siblings) have also inherited the susceptibility genes.4 Family members should definitely be tested.
Specifically, Celiac Disease is associated with both HLA genes and non-HLA genes. HLA is short for human leukocyte antigen. Leukocytes are simply white blood cells. The genetic markers for Celiac Disease are certain HLA molecules known as HLA-DQ2 and/or HLA-DQ8.HLA molecules mark cells as 'antigens', meaning they are detected as "non-self." Unfortunately, in Celiac Disease, HLA is marking our own tissues as objects for attack by antibodies. About 90 to 95% of celiacs have HLA-DQ2 and 5 to 10% have HLA-DQ8. Some people, however, with Celiac Disease do not show either of these HLA molecules.5
Protein does not normally provoke an immune response when we eat it. And gluten protein does not always provoke an immune response in susceptible people who eat it. However, known triggers are:
- environmental - eating a diet overloaded with gluten.
- pathological - an intestinal infection (virus, parasite, yeast, or bacteria).
- physical - an operation, pregnancy, or strenuous exercise.
- situational - unusual stress (emotional, mental, or psychological).
3. Antibody production: hallmark of active Celiac Disease
The antibody response causes intense inflammation of our duodenum (small intestine closest to the stomach where most nutrients are actively absorbed) and decreases further along toward the large intestine. Diarrhea usually indicates extensive damage.
Antibodies are protective proteins produced by our immune system in response to specific substances (antigens) that our body perceives to be threatening. Auto-antibodies are proteins that react against our body's own molecules or tissues as if they are threatening substances and their target is called an auto-antigen. In the case of Celiac Disease, the two classes of specific antibodies/ auto-antibodies mainly involved are immunoglobulin-A (IgA) and immunoglobulin-G (IgG). IgA antibodies are short-lived, lasting about 2 weeks while IgG antibodies are long-lived, lasting about 6 months.
Immunoglobulins link with antigens at specific sites on the antigen's surface. This linkage creates an antibody-antigen reaction. After linkage, natural killer cells bind with the antibodies to destroy the linked antigen. Antibodies that target our own cells or substances are called auto-antibodies. In Celiac Disease, auto-antigens are endomysium cells (EMA) and tissue transglutaminase (tTG), a common enzyme in tissue.
The immune response begins within 2 to 4 hours of eating gluten.6
Blood tests for Celiac Disease look for auto-antibodies to tissue transglutaminase and endomysium, if they have been produced. Read more...Diagnosis/ Testing
4. Increased intestinal permeability appears early in Celiac Disease
Increased Intestinal Permeability is also called Hyperpermeability and Leaky Gut Syndrome. Increased Intestinal Permeability involves the abnormal passage of substances from inside our small intestine to our bloodstream and lymph system.
In health, the cells lining our intestines (enterocytes) adhere tightly side-by-side to each other, forming tight junctions. Tight intercellular junctions are part of a complex "barrier" system that determines what substances and how much may be allowed to cross from the intestine to the bloodstream. Enterocytes selectively permit molecules to permeate or pass through their normal tight junctions under very specific and controlled circumstances. The interplay between genes and gluten that leads to the intestinal damage is normally prevented by competent tight intercellular junctions. ((Clemente MG, De Virgiliis S, Kanh JS, et al. “Early effects of gliadin on enterocyte intracellular signalling involved in intestinal barrier function.” Gut. Feb 2003;52(2):218-223.))
In Celiac Disease, the early steps that allow toxic molecules to cross the intestinal barrier lead to a rapid increase in intestinal permeability. ((Clemente MG, De Virgiliis S, Kanh JS, et al. “Early effects of gliadin on enterocyte intracellular signalling involved in intestinal barrier function.” Gut. Feb 2003;52(2):218-223.)) Both gastric (stomach) and small intestine permeability are disrupted in people with Celiac Disease. ((Fahardi A, Banan A, Fields J, Keshavarzian A. “Intestinal barrier: an interface between health and disease.” Journal of Gastroenterology and Hepatology. 2003;18:479-497.))
The Symptoms of Celiac Disease
Each case of Celiac Disease is unique. Symptoms of untreated Celiac Disease not only vary between individuals but also vary even in the same individual at different times. Although there are hundreds of possible symptoms, we may only have one or we could have many.
Early on, undamaged areas of intestine compensate for malabsorption that occurs in damaged areas. We may simply feel tired or irritable. Many people experience forgetfulness or apathy, which is the lack of interest in or care about things we should. Eating gluten every day makes it difficult to associate symptoms with gluten-containing foods. Feeling dragged down or lousy makes it even harder to get a handle on symptoms.
As damage progresses, we may become more tired, depressed and stressed whether or not we have digestive problems. However, digestive problems may be dramatic, such as heartburn/ gastric reflux, abdominal pain, bloating, diarrhea or constipation. At some point, we may develop any of a huge array of problems, including hair loss, muscle cramps, skin conditions, vision changes, clotting disorders, and auto-immune diseases. Untreated Celiac Disease increases the rate of cancer 2 to 3 times the average rate. ((Green, P. “Celiac Disease, an Emerging Epidemic.” Presentation by Dr. Peter Green, M.D. Clinical Professor of Medicine and Director of The Center for Celiac Disease Research at Columbia University as given at the Center. Sep 2005.)) Read more...Symptom Guide.
How Celiac Disease Sypmtoms Present
There are two popular techniques to describe how people can show symptoms. One is an illustration of an iceberg and the other involves a classification chart for grouping patients. Both are shown below.
The iceberg diagram below depicts the relationship of villous atrophy to patient symptoms in people who are producing antibodies. In this we can see how few people show symptoms despite damage that can be significant.
Figure 1.5 Relationship between intestinal damage and symptoms in people with antibody production.
There is an existing classification of patients with commonly accepted features.7 This classification is a uniform method of depicting the relationship between symptoms and blood/ biopsy findings in patients. It was developed to group how people can present (appear to their doctor). The groups are:
1) Classical Celiac Disease, 2) Celiac Disease with Atypical Symptoms, 3) Silent Celiac Disease, and 4) Latent Celiac Disease.
- Classical Celiac Disease is dominated by symptoms and sequelae of gastrointestinal malabsorption. The diagnosis is established by serological testing, biopsy evidence of villous atrophy, and improvement of symptoms on a gluten-free diet.
- Celiac Disease with Atypical Symptoms is characterized by few or no gastrointestinal symptoms, and extraintestinal manifestations predominate. Recognition of typical features of Celiac Disease is responsible for much of the increased prevalence. As recognition improves, atypical symptoms may become the most common presentations. As with Classical Celiac Disease, the diagnosis is established by serological testing, biopsy evidence of villous atrophy, and improvement of symptoms on a gluten-free diet
- Silent Celiac Disease refers to individuals who are asymptomatic but have a positive serologic test and villous atrophy on biopsy. These individuals are usually detected via screening of high-risk individuals, or detection of illlous atrophy by endoscopy and biopsy conducted for another reason
- Latent Celiac Disease is defined by a positive serology but no villous atrophy on biopsy. These individuals are asymptomatic, but later may develop symptoms and/or histologic changes.
How Can I Tell If I Have Celiac Disease?
- If you have already been diagnosed with an itchy skin condition called Dermatitis Herpetiformis, you definitely have Celiac Disease and do not need antibody testing. Dermatitis Herpetiformis rapidly responds to a gluten-free diet.
- If a close family member has been diagnosed with Celiac Disease or Dermatitis Herpetiformis, please see your doctor to be tested.
- If you have one or more problems listed in our Symptom Guide that are not otherwise explained, please see your doctor to be tested.
- If you feel worse after eating pizza, bagels, or imitation meat (seitin which is 100% gluten) or feel better when you don't, please see your doctor to be tested.
- If you have an auto-immune disorder, especially Type 1 Diabetes Mellitis, Thyroid Disease, Liver Disease, Psoriasis, Alopecia Areata, or Sjogran's Syndrome, please see your doctor for testing.
A simple blood test for antibodies can identify a reaction that is specific for Celiac Disease. Your doctor may want to confirm the diagnosis with a biopsy of your intestinal lining. Read more... Diagnosis/Testing.
HOW MANY PEOPLE ARE AFFECTED BY CELIAC DISEASE?
Over the past two decades, advances in understanding of the multi-system nature of active Celiac Disease and the identification of sensitive blood tests have led to the recognition that Celiac Disease is much more common than previously thought. The previously maintained assumption that Celiac Disease is a rare disease was a common error that caused failure by doctors to diagnose it.8
Population-based studies suggest that up to 3,000,000 Americans are affected.2 A study of Denver children under age 5 demonstrated a prevalence of 0.9 percent, which is about 1 in 100. ((Hoffenberg EJ, MacKenzie T, Barriga KJ, et al. A prospective study of the incidence of celiac disease. Journal of Pediatrics. Sep 2003;143 (3):308-314.)) The prevalence is higher in high risk groups. For example, Celiac Disease occurs in 8% of persons with Down Syndrome and 34% of those with Anti-Phospholipid Syndrome.
IS THERE A CURE?
No. But research is intensifying and attracting talented investigators. The great strides made into understanding Celiac Disease have opened the door to understanding other auto-immune disorders like Type 1 Diabetes Mellitus. The fact remains that the clinical outcome depends on duration of exposure to gluten.9 That is, the sooner we stop eating gluten, the lower our risk will be for developing associated disease or complications and the better our health will become.
WHAT IS THE TREATMENT FOR CELIAC DISEASE?
Treatment of Celiac Disease is a strict gluten-free diet that results in rapid healing of the intestinal mucosa, improvement or resolution of most nutrient deficiencies and many health problems. Associated disorders and complication may require specific medical treatment.
Intestinal inflammation stops immediately and damage to the lining is reversed simply by not eating gluten. This way of preparing and choosing food that does not contain wheat, rye, barley, and oats is called a gluten-free diet. It is a restrictive diet because we must absolutely restrict or not eat food with gluten. Only 1/8th of a teaspoon of flour can cause intestinal damage.
Managing a gluten-free diet requires knowing which foods to strictly avoid. It is a challenge because many popular prepared foods both in grocery stores and in restaurants are made with gluten grains. Unlike weight loss diets, this diet must be maintained for life. Like all things that require substantial change, we need to understand what is involved in order to comply with this simple management.
On the bright side, there are no expensive pills to take or injections to endure. See for yourself. If you persevere for 2 weeks, you will quickly enjoy the many health and wellness advantages that result from going gluten-free. Read more...Diet Guide
"Get well, look good, and stay healthy living gluten free."™
National Institutes of Health, "National Institutes of Health Consensus Development Conference Statement, Celiac Disease," August 9, 2004;1-14. ↩
Libonati, C. Recognizing Celiac Disease. GFWorks Publishing. 2006. ↩
Fasano, A. "Where have all the American celiacs gone?" Acta Paediatrica Supplement. 1996;412:20-24. ↩
National Institutes of Health, “National Institutes of Health Consensus Development Conference Statement, Celiac Disease,” August 9, 2004;1-14. ↩
Murray, J., “The widening spectrum of celiac disease.” American Journal of Clinical Nutrition. Mar 1999;69(3):354-365. ↩
National Institutes of Health, “National Institutes of Health Consensus Development Conference Statement, Celiac Disease,” August 9, 2004;1-14. ↩
Cook M. “Common errors in diagnosing celiac disease in adults.” Physician Assistant. Mar 2001;4. ↩
Ventura A, Maguzzi G, Greco L. Duration of exposure to gluten and risk for autoimmune disorders in patients with celiac disease. Gastroenterology. Aug 1999;117(2):287-303. ↩