Vol. 9 Issue 11
Making the Connection
Underdiagnosed in the U.S., celiac disease can be identified and treated if the condition is understood
Celiac disease is a common food sensitivity that can be the underlying source of hundreds of health problems mistakenly attributed to other causes. This insidious disorder has the potential to disfigure, disable and destroy lives at any age. Yet, of the 3 million affected Americans, only 3 percent are diagnosed and treated.1Prevalence rates are higher in certain populations, such as blood relatives of a person with celiac disease and those with autoimmune disorders.
Unfortunately, people in the U.S. with this condition actively seeking help for their symptoms can go a lifetime without diagnosis and proper treatment. Typically, worldwide diagnosis is faster.
Genetic Susceptibility & Gluten
Celiac disease is also called celiac sprue, nontropical sprue, gluten-sensitive enteropathy or simply celiac by the public.
This immune-mediated disorder stems from an inherited lifelong intolerance to the gluten protein found in wheat, barley, rye and oats. When ingested, gluten resists the breakdown action of normal digestive enzymes into harmless amino acids. Undigested peptides precipitate hyperpermeability of the small intestinal lining (so-called "leaky gut") to breach the intestinal barrier defense system. In this way, gluten unnaturally gains entrance to the lamina propria.
Within the lamina propria, gluten peptides encounter the enzyme transglutaminase and the local immune system. Transglutaminase deamidates, or breaks off, the rich glutamine residues in gluten. This deamidation creates the toxic molecular compounds, or epitopes, the immune system identifies as foreign.
These epitopes trigger autoimmune antibodies in genetically susceptible individuals. Ensuing inflammation swells affected portions of the small intestinal lining and damages its delicate structures, interfering with its function to finish digestion and absorb nutrients.
While gluten itself is the environmental cause for antibody development, some stressors that can trigger active disease include gluten overload, pregnancy, viral gastrointestinal infection, surgery and severe stress.
Recognizing Celiac Disease
Despite dramatic advancements in knowledge and testing procedures, recognition of this multifaceted disorder is lacking.1Celiac disease often is undiagnosed due to ignorance of the following:
Pathophysiology The traditional description of celiac disease as an intestinal disorder with malabsorption as the primary defect is a shadow of the real condition.
Prevalence In contrast to the historic belief celiac disease affected just one in 5,000 individuals, antibody testing demonstrated prevalence of one in 100.
Diagnostic tests Healthcare providers are unfamiliar with new and improved testing methods.
Manifestations Many patients do not have diarrhea and wasting symptoms of classic celiac disease. Extraintestinal symptoms predominate in people with atypical symptoms.
How It's Diagnosed
Diagnosis of celiac disease is made by a positive serologic antibody study and confirmed by histological findings of small-bowel biopsy specimens obtained by endoscopy and improved clinical response following a gluten-free diet.
The single most important step in diagnosing celiac disease is to recognize its myriad clinical features. No single test can definitively diagnose or exclude celiac disease in every individual; there also is a continuum of laboratory and histopathologic results.1
Positive anti-endomysium antibodies and positive anti-tissue transglutaminase antibodies show celiac disease. Positive antigliadin antibodies demonstrate sensitivity to gliadin itself, the gluten in wheat.
Not all patients have positive antibodies at presentation. When symptoms are present but test results are negative, further testing is warranted, including selective immunoglobin A deficiency. In the event the patient started a gluten-free diet prior to testing, suggest a gluten challenge of 3 months or longer in the expectation of antibody development.
Positive small intestinal biopsy shows the degree of villous atrophy, yet this is not foolproof either. The gastroenterologist must be skilled in taking accurate specimens from multiple sites, and the pathologist must be skilled in examining them properly. In addition, damage may be submicroscopic, returning a level not yet detectable by histological examination.
Additional studies include sonogram and genetic testing. Sonogram shows edema and abnormal appearance of the bowel wall. This is especially helpful for children or those who cannot undergo an endoscopy.
More than 97 percent of people with celiac disease share the same genetic human leukocyte antigen (HLA) haplotype markers, HLA-DQ2 and HLA-DQ8. While HLA genotyping is not specific for celiac disease, it has a very high negative predictive value. If the markers are not present, genetic testing essentially rules out the disease.
Annual follow-up testing is warranted for patients with negative test results who continue to show symptoms.
There are no typical symptoms of celiac disease, although the most common clinical presentation is unexplained iron-deficiency anemia with or without gastrointestinal symptoms.
Celiac disease, by way of malnutrition, immunity or the direct toxic effect of gluten on cellular structures, has the potential to produce a broad range of symptoms, associated disorders and complications that may affect any organ or body system. Manifestations vary and may appear at any age.
Nutrient deficits are responsible for many seemingly unrelated conditions, such as depression, inability to concentrate, anxiety, insomnia, defective tooth enamel, coagulopathies, hypertension, obesity, anorexia and excessive thirst.
Associated autoimmune disorders may affect any body tissue, including type I diabetes mellitus, hypothyroidism and Grave's disease, to name a few. Further, severe complications include various cancers such as B-cell non-Hodgkin lymphoma, cryptic intestinal T cell lymphoma and enteropathy-associated T cell lymphoma.
Chronic diarrhea in childhood should provoke screening. Pediatric presentation for celiac disease could involve hypotonia, failure to thrive, growth retardation, short stature, convulsions, poor bone and tooth development, thymic atrophy and delayed puberty.
Treatment is a gluten-free diet. Excluding gluten usually results in rapid healing of the small intestinal mucosa, resolution or improvement of nutritional deficiencies, and disappearance of many manifestations of celiac disease.
The gluten-free diet is challenging due to the plethora of gluten-containing foods in the standard American diet. To succeed, patients need detailed diet instruction, including how to read food labels and identify hidden sources of gluten, such as in medications and supplements. Refer patients to a qualified dietitian if possible; otherwise, nurses can teach appropriate information.
Inform patients about community help such as celiac support groups, which offer practical advice on how to shop and cook, and where to dine. Many support groups hold their meetings at local hospitals.
Clinical outcome depends on duration of exposure to gluten. The longer gluten is consumed, the more the body is damaged, and the greater the likelihood of health disorders and complications developing.
Intestinal permeability improves within 2 months of starting a gluten-free diet. Despite a good clinical response, abnormal endoscopic and histologic appearances persist in the majority of patients.2Patients who receive adequate education about celiac disease and treatment with the gluten-free diet are better able to prevent intestinal damage and improve their health by dietary self-management. Clearly, nursing intervention that uncovers hidden celiac disease, provides nutritional education and promotes regular follow-up will considerably improve prognosis. n
References for this article can be accessed at www.advanceweb.com/nurses. Click on Education, then References.
Cleo Libonati is author of Recognizing Celiac Disease, and co-founder, president and CEO of Gluten Free Works Inc., Ambler, PA.