April 2013 Issue
Celiac Disease and Gluten Sensitivity — Learn About the Differences Plus Counseling Strategies for Patients
By Marlisa Brown, MS, RD, CDE, CDN
Vol. 15 No. 4 P. 12
Jessica, 52, suffered from bloating, gas, diarrhea, and other gastrointestinal (GI) problems. She recently was diagnosed with irritable bowel syndrome (IBS) and hypothyroidism. Results from her blood work and an endoscopy procedure were negative for celiac disease. However, Jessica still decided to begin eating a gluten-free diet and felt better almost immediately.
After telling her physician her GI symptoms disappeared once she started following a gluten-free diet, Jessica was told something might have been missed during testing, and that she should reintroduce gluten for six weeks to repeat the tests. The moment Jessica started eating gluten, she became ill, but she continued consuming gluten during the six-week period. She was retested for celiac disease and told once again her results were negative, that IBS was causing her symptoms, and that she didn’t need to follow a gluten-free diet. Nevertheless, Jessica began eating a gluten-free diet again and her symptoms vanished.
This scenario is typical in that many patients suffering from celiac disease symptoms don’t have celiac disease. Instead, they have what’s called gluten sensitivity, which often goes undiagnosed.
This article will define celiac disease and gluten sensitivity and discuss the differences between each condition, the proper protocol for an accurate diagnosis, and tips for counseling patients from RDs at the forefront of the latest research.
Defining the Differences
Celiac disease is an autoimmune disorder characterized by a permanent intolerance to the protein gluten, which is found in wheat, rye, barley, and other grains. When people who have celiac disease consume gluten, their immune system responds by damaging the fingerlike villi in the small intestine, preventing them from absorbing vital nutrients such as iron, folate, calcium, and vitamin D.
If celiac disease is left untreated, it can result in the development of GI and non-GI symptoms, such as diarrhea, bloating, gas, constipation, fatigue, and complications such as headache and joint pain, nutritional imbalances, and diseases such as Hashimoto’s thyroiditis, autoimmune hepatitis, type 1 diabetes and, in rare cases, intestinal cancer. The only known treatment for celiac disease is to follow a gluten-free diet for life. Even the smallest amount of gluten can trigger an immune response.
Approximately 1% of the US population, or 3 million people, has celiac disease.1 There has been a four- to fivefold increase in the prevalence of celiac disease in the past 50 years, according to a study published in the July 2009 issue of Gastroenterology.
Gluten sensitivity is a term used to describe individuals who can’t tolerate gluten but who don’t have celiac disease. After eating gluten-containing foods, people with gluten sensitivity generally experience GI symptoms but not intestinal damage.2 In recent years, the term gluten sensitivity has been recognized and described by several sources.3,4
Dietitians may ask why patients without celiac disease experience symptoms of the condition. “Gluten is a combination of several proteins that are complex and not easily digested by humans,” says Alessio Fasano, MD, director of the Center for Celiac Research and the Mucosal Immunology and Biology Research Center at MassGeneral Hospital for Children in Boston. “For most people, this incomplete breakdown of gluten peptides doesn’t cause a problem, and the gluten fragments pass without trouble through the digestive tract. For certain people with the genetic susceptibility to gluten-related disorders, the undigested gluten can create problems.”
Moreover, when gluten is ingested and reaches the small intestine, it can trigger an immune response leading to increased intestinal permeability and, ultimately, inflammation in genetically susceptible individuals, Fasano says. Early research suggests that gluten sensitivity may not trigger an autoimmune response like that of celiac disease. Much research is under way in this area, so the healthcare community can expect more information on these issues in the near future, he adds.
It’s currently unknown whether gluten sensitivity has long-term health consequences. Symptom severity, the amount of gluten tolerated, and whether following a gluten-free diet for life is necessary can differ from person to person.
To date, no diagnostic tests are available to diagnose gluten sensitivity. The manner in which it’s diagnosed involves a process of elimination: rule out a wheat allergy and celiac disease, and if a patient responds favorably to a gluten-free diet, he or she is diagnosed with gluten sensitivity.5,6
Gold Standard for Diagnosing Celiac
Top researchers say that approximately 85% of those who have celiac disease remain undiagnosed because of a lack of awareness of the latest diagnostic tools. To date, many of the blood panels physicians request don’t always include the recommended tests, and the number of biopsy samples taken often is inadequate and misinterpreted.
Researchers say the gold standard for diagnosing celiac disease should be an endoscopy with a duodenal biopsy. The biopsy should involve taking samples of the duodenum located in the small intestine. A pathologist should interpret the results using Marsh standards to measure the degree of villous atrophy, a condition in which the villi that line the small intestine are flattened, preventing them from absorbing vital nutrients. This flattening usually is found in patches throughout the intestine; one area of the intestine may be flattened, yet another may appear normal. Marsh ratings are interpreted with a numeric value as follows: 0, normal; 1, usually not celiac disease but more likely another disorder; 2, uncommon with celiac disease; 3a, 3b, and 3c, celiac disease.
In many cases, pathologists who aren’t affiliated with a celiac disease research center aren’t GI pathologists and may misinterpret the samples. One study showed that misdiagnoses are more common in non–research-based settings, such as in an individual GI office.7 If a diagnosis ever is in question, patients can request copies of their slides to have a GI pathologist at a celiac disease research center review and interpret the results.
The other obstacle to obtaining an accurate celiac disease diagnosis occurs during the endoscopy procedure, since many physicians don’t take a sufficient number of biopsy samples from the duodenal region, says Peter H. R. Green, MD, director of the Celiac Disease Center at Columbia University in New York City. It’s recommended that doctors take four to six tissue samples from the duodenum. Studies have shown there’s a linear relationship between the number of samples taken and the percentage of people diagnosed with celiac disease.8
The biggest barrier to obtaining a positive celiac disease diagnosis is the lack of awareness of the latest diagnostic tools, according to Fasano. He says the field of celiac disease diagnosis, treatment, and management is continually changing, although much more is known now than 10 years ago. Many patients continue to go undiagnosed if they present with atypical celiac disease symptoms, such as canker sores, dry eyes, numbness in their hands and feet, migraine headaches, and obesity, especially if physicians aren’t using current diagnostic criteria.
In some cases, physicians can perform a capsule endoscopy to detect celiac disease when the use of a traditional endoscope is contraindicated in certain patients, for example, those suffering from hemophilia because of their risk of bleeding. Physicians also can order a capsule endoscopy to look further into areas of the small intestine that otherwise would be difficult to reach.
Of course, these test results are subject to interpretation, and inexperienced pathologists can miss a celiac diagnosis if they’re not skilled in reviewing these types of images, says Benjamin Lebwohl, MD, an assistant professor of clinical medicine and epidemiology at the Celiac Disease Center at Columbia University. Even medication use can cause a misinterpretation of test results. Recent studies have found that some medications, such as the immunosuppressant mycophenolic acid (CellCept, Myfortic) and the angiotensin II receptor antagonist olmesartan medoxomil (Benicar), can produce an enteropathy of flattened villi, which can mimic celiac disease and lead to a possible misdiagnosis.9,10
Blood Work and Genetic Testing
Before a physician performs an intestinal biopsy, blood work and genetic tests are ordered as part of the screening process. Before the blood work, the patient must eat gluten-containing foods for a certain period of time to achieve more accurate results. In general, the protocol for a gluten challenge is to have a patient eat at least two slices of bread per week for a minimum of two to six weeks. However, gluten consumption won’t affect genetic testing (eg, HLA-DQ2 and DQ8), which can be done at any time. Genetic tests simply determine whether a patient is genetically predisposed to developing celiac disease, Lebwohl says.
The blood tests considered most effective to indicate possible celiac disease include tissue transglutaminase antibody (tTG) immunoglobulin A (IgA) and total IgA. The IgA test is performed because an IgA deficiency is common in celiac patients. In addition, an IgA deficiency affects the accuracy of the tTG IgA test since the tTG IgA depends on IgA being present.
Also available is the deamidated gliadin peptide (DGP) test, which isn’t affected by an IgA deficiency and may be helpful in diagnosing young children.
Although these blood tests are useful, they’re not used to diagnose celiac disease; an intestinal biopsy is. The only other diagnostic criterion is the presence of dermatitis herpetiformis. Patients who have this condition are considered positive for celiac disease. Children sometimes can be diagnosed without the need for an intestinal biopsy when specific indications are present such as positive serology, positive genetic factors, and a positive response to following a gluten-free diet.11
Case Studies: Working With Patients
“Patients shouldn’t go gluten free without getting diagnosed first,” notes Shelley Case, BSc, RD, a consulting dietitian and the author of the Gluten-Free Diet: A Comprehensive Resource Guide. “This is so important because there are long-term consequences with celiac disease, and without a diagnosis patients may be less compliant long term. Also, other family members are less likely to be screened.”
Whenever Case sees a patient whom she suspects has celiac disease but has had negative biopsy results, she asks to see the report as well as a copy of the serology. If there were only a few samples taken, she knows celiac disease could have been missed. She checks to see whether the right blood work was ordered and asks the patient whether he or she was eating gluten until the time of testing. Overall, Case says the overarching message for physicians and RDs is to keep abreast of the emerging research on celiac disease and gluten sensitivity so they can appropriately screen, test, diagnose, and treat patients.
Some dietitians have participated in some of the latest research on celiac disease. Anne Lee, MSEd, RD, LD, director of nutritional services for the Dr Schär Institute, says, “Dr Schär has had the opportunity to work with the leaders in celiac disease and gluten sensitivity for many years. Our work within the area of gluten sensitivity started with the first consensus conference held in London in 2011. These findings were presented at the International Celiac Disease Symposium, a special preconference workshop in Oslo, Norway, that year. From this great event, many scientific publications have been generated as well as consumer and healthcare professional educational materials.”
Lee counseled patients suffering from gluten sensitivity when she worked at the Celiac Disease Center at Columbia University as a nutrition specialist. She had patients who responded favorably to a gluten-free diet even though they didn’t have celiac disease. Most of these patients self-diagnosed themselves before the clinical criteria of gluten sensitivity was established, but Lee knew there was something going on with these patients.
“That’s why it’s so important to make the proper diagnosis so RDs can map out a treatment plan to help patients,” she says. “With proper awareness, patients will no longer be told their symptoms are all in their heads. I believe the future is bright, and that diagnostic tools will be developed to help with this preprocess.”
Dietitians must keep in mind that diagnostic criteria for both celiac disease and gluten sensitivity aren’t always accurate. Awareness of the latest diagnostic tools and knowing what signs and symptoms to look for are the goals, especially since RDs are in the unique position to help identify patients who haven’t been previously diagnosed and provide gluten-free meal plans. Dietitians who educate themselves about the latest research become the main source of knowledge for all patients who must follow a gluten-free diet.
— Marlisa Brown, MS, RD, CDE, CDN, is president of Total Wellness Inc, a private nutrition consulting company specializing in diabetes, cardiovascular disease, gastrointestinal disorders, gluten-free diets, culinary programs, corporate wellness, and medical nutrition therapies, and author of Gluten-Free Hassle-Free and Easy Gluten-Free.
Gluten-Free Meal Ideas
Eating gluten free can be easy and delicious. The trick is to start with fresh, naturally gluten-free foods. Here’s a list of foods for breakfast, lunch, dinner, and snacks from which clients can choose:
• Gluten-free pancake mix prepared with ground flaxseeds and chopped walnuts with all-fruit spread and skim milk
• Low-fat cottage cheese layered with berries and melon in a parfait glass and topped with sliced toasted almonds
• Corn or Rice Chex (or favorite whole-grain gluten-free cereal) with blueberries and skim milk
• Plain nonfat Greek yogurt served with a sliced banana, ground flaxseeds, and a drizzle of honey
• Gluten-free instant oatmeal such as Glutenfreeda
• Chickpeas, chopped onions, carrots, garlic, and a drizzle of olive oil and lemon juice over baby spinach
• Sliced grilled chicken with grapes, pecans, and fat-free gluten-free ranch dressing served with a warm Dr Schär’s gluten-free whole grain roll
• Gluten-free sliced turkey (eg, Boar’s Head) with roasted peppers and honey mustard on an Udi’s whole grain roll
• Quesadillas made with corn tortillas, gluten-free salsa, and low-fat American cheese
• Shrimp, zucchini, onion, and tomato kebabs drizzled with low-fat Italian dressing and served over a mixed green salad
• Baked lean turkey burger topped with tomato sauce and melted low-fat mozzarella on an Udi’s whole grain burger roll with steamed broccoli
• Roasted chicken served with a marinated mixed vegetable salad or coleslaw made with fat-free Italian dressing and quinoa pilaf
• Grilled eggplant and zucchini layered with bean salad and drizzled with olive oil, minced garlic, lemon juice, and a shaving of Parmesan cheese
• Baked chicken breast topped with gluten-free barbeque sauce with a small sweet potato and steamed green beans
• Baked lean pork loin with a gluten-free spice rub served with natural applesauce, corn, and a side salad
• Sliced sirloin steak over a mixed green salad with sliced roasted potatoes and chopped vegetables with low-fat gluten-free balsamic dressing
• Baked tilapia cooked in an aluminum packet topped with sliced onions, carrots, tomatoes, garlic, cumin, and lemon served over millet
• Gluten-free bars such as KIND or LARABAR
• 1/2 peanut butter sandwich on a Dr Schär’s gluten-free multigrain roll or peanut butter on a banana
• Lite yogurt or yogurt shake
• Gluten-free meal shake such as Boost or Ensure
• JELL-O gelatin or fat-free pudding
• 1/2 cup gluten-free low-fat ice cream
• Small piece of fresh fruit or 1 cup of fruit salad
• Gluten-free fruit leather
• 1 oz unsalted nuts
• Low-fat string cheese with mini box of raisins
• Air popped popcorn
• 1 cup gluten-free soup
• Gluten-free rice cakes, plain or with almond butter
• Corn chips or bean chips with salsa
• Gluten-free light flavored soy, rice, or coconut milk
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