A review of 5 years of studies shows that celiac disease and gluten sensitivity are distinct, with diagnosis directly impacting long-term treatment
By Amy Ratner, Beyond Celiac Medical and Science News Analyst
It’s important for physicians to distinguish between celiac disease and non-celiac gluten sensitivity because of the impact correct diagnosis has on long-term treatment, researchers concluded after reviewing more than five years of studies on both conditions.
In an article published in the Journal of the American Medical Association (JAMA) experts from the Center for Celiac Research and Treatment at Mass General Hospital for Children also called for close follow-up for celiac disease patients to monitor how well they are following the diet, whether they have nutritional deficiencies and whether they are developing comorbidities.
Comorbidity: Two disorders or illnesses occur in the same person, simultaneously or sequentially. Comorbidity also implies interactions between the illnesses that affect the course and prognosis of both.
Strict adherence to the diet is critical, with the article noting that trace amounts of gluten, typically from cross-contact, can be as harmful as not following the diet.
Celiac disease experts recognize the danger of exposure to minimal amounts of gluten and are researching treatments that would be used in addition to the diet to better protect celiac disease patients. Beyond Celiac just launched Go Beyond Celiac, a digital community designed to accelerate treatment options by collecting critical data about celiac disease that’s not otherwise being tracked and by connecting patients and researchers for clinical trials.
The JAMA article also concludes there is no scientific evidence to suggest that a gluten-free diet is part of a healthier diet or helpful in treating obesity.
Alessio Fasano, M.D., director of the celiac center and an author of the article, said facts about the gluten-free diet are needed more than ever.
“With the rapid rise of the gluten-free diet in popularity and the rise of gluten-related disorders in general, it is even more critical to provide accurate information to practitioners and individuals about the possible role of gluten in health disorders,” he said. “Our goal was to provide a comprehensive picture for diagnosis and treatment of celiac disease and non-celiac gluten sensitivity.”
The researchers’ evidence-based update on the pathophysiology, diagnosis, treatment and implications of celiac disease and gluten sensitivity noted the following points related to celiac disease:
- Celiac disease occurs in about 1 percent of the general population, with some regional differences.
- Improved tests to diagnose celiac disease have resulted in more accurate measurement of its prevalence and helped establish it as a systemic autoimmune disease that can occur at any age, with intestinal and other symptoms, including 23 outlined in the study.
- Iron-deficiency anemia is the second most common clinical symptom of celiac disease in adults. Diarrhea is the first. In children, poor growth, delayed puberty and tooth enamel defects can be symptoms of celiac disease.
- The IgA tTG test should be done first when celiac disease is suspected. Evidence shows it is an “excellent” screening tool. A biopsy of the small intestine that shows blunting of the villi confirms the diagnosis.
- Celiac disease occurs more frequently in at-risk groups, including those with Type 1 diabetes, autoimmune thyroid disease, Down, Turner and Williams syndromes, IgA deficiency and nephropathy and juvenile idiopathic arthritis.
- First-degree family members have a 15- to 25-fold higher frequency of developing celiac disease. Adult and pediatric gastroenterology groups in the United States recommend screening of first degree relatives, whether they have symptoms or not. If initial blood tests are negative, repeated testing is recommended throughout the relatives’ lives. But the researchers note that the US Preventative Services Task Force recently concluded there is not enough evidence to justify screening of those without symptoms, including first degree family members. The task force said evidence on benefits and risks of screening is inadequate.
- Testing for HLA-DQ2 and HLA-DQ8 genes can be helpful in determining whether high-risk groups need to be tested for celiac disease. Absence of the genes rules out celiac disease. Presence of the genes alone does not indicate celiac disease, since 40 percent of the general population has them. Celiac disease antibody testing is still needed for diagnosis.
- When someone has celiac disease, an inflammatory process begins when the immune surveillance system mistakenly recognizes gluten as a pathogen.
- Innate immunity plays a critical role in initiating celiac disease and possibly gluten sensitivity.
- In celiac disease, adaptive immunity comes into play when selected gluten peptides activate T-cells which multiply, causing damage to intestinal epithelial cells. Fingerlike projections in the small intestine are blunted and the grooves between the villi deepen.
Antigen: Any substance that causes your immune system to produce antibodies against it.
Intestinal epithelial cells: Cells that define the boundary between tissues of the intestine and the external environment. They receive and interpret assaults from the intestinal lumen and signal to the tissues whether inflammation will occur.
Innate immunity: Nonspecific defense mechanisms that come into play immediately or within hours of an antigen's appearance in the body. These mechanisms include physical barriers such as skin, chemicals in the blood, and immune system cells that attack foreign cells in the body. The innate immune response is activated by chemical properties of the antigen.
Adaptive immunity: An antigen-specific immune response. The adaptive immune response is more complex than the innate. The antigen first must be processed and recognized. Once an antigen has been recognized, the adaptive immune system creates an army of immune cells specifically designed to attack that antigen. Adaptive immunity also includes a "memory" that makes future responses against a specific antigen more efficient.
- The gluten-free diet is currently the only treatment for both celiac disease and gluten sensitivity. Celiac disease patients have to follow the diet for life.
- Both celiac disease and gluten sensitivity patients need to be monitored by a gastroenterologist and dietitian knowledgeable about the gluten-free diet because of the challenges the diet presents and the harm that even trace amounts of gluten presents.
- For celiac disease patients, nutritional markers should be evaluated at diagnosis and abnormal findings reassessed after the patient has been on the gluten-free diet for one year. Celiac disease antibodies should be measured every 6 to 12 months after diagnosis until they normalize, which is interpreted as a sign that the intestine has healed. A recent Beyond Celiac study found that one in four patients diagnosed in the past five years do not get the needed follow up with their doctor or dietitian.
- Although antibody tests are used to monitor if a celiac disease patient is following the gluten-free diet and intestinal healing is taking place, the tests have not been validated for this purpose. A recent study showed that the sensitivity of the tTG test in identifying persistent celiac disease after a patient has started a gluten-free diet ranges from 43 to 83 percent.
- Since current blood tests may be inadequate in predicting intestinal recovery in celiac disease patients who follow a gluten-free diet, a follow-up endoscopy to measure recovery is recommended in some celiac disease centers.
- The gluten-free elimination diet, which allows only fresh fruits, vegetables, meat and limited condiments, is a treatment option for celiac disease patients who have persistent damage to the intestinal villi despite following a typical gluten-free diet. Use of immunosuppressants is another option. Monitoring by a gastroenterologist with expertise in celiac disease is needed in both cases.
- The cumulative risk of developing other autoimmune diseases is reduced in celiac disease patients following a gluten-free diet compared to patients not following the diet for at least 10 years.
- The recent review of data from multiple studies, called meta-analysis, suggested that overall malignancy risk in celiac disease patients was not elevated compared with the risk in general population controls. However, individual cancers such as lymphoproliferation and gastrointestinal cancers may still be positively associated with celiac disease.
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