Celiac Disease

May is Celiac Disease Awareness Month. As you are aware, the world of gluten-induced symptoms is confusing and patient awareness is increasing. We will provide an overview of celiac disease as well as discuss nonceliac gluten sensitivity (aka gluten intolerance).

Celiac disease, also known as celiac sprue, nontropical sprue, and gluten-sensitive enteropathy, is an inherited autoimmune disorder that affects the small intestine. When an individual with celiac disease ingests gluten, a protein found in wheat, rye and barley, the immune system responds by attacking the small intestine which then limits or inhibits the absorption of important nutrients.

Gluten is a protein that cannot be fully digested. Early humans likely did not eat grains and, therefore, did not evolve the ability to digest gluten. Today, farmers and consumers prefer protein-rich varieties of grains that produce greater yields. Higher gluten content improves texture and makes for denser pretzels and pizza crusts.

Currently, celiac disease affects 1.7 million Americans with a prevalence of 1 in 141 or 0.71%. In the U.S., celiac disease primarily affects White Non-Hispanics with a prevalence of 1.01%, but can affect African-, Hispanic-, and Asian-Americans. Only 1 in 6 patients with celiac disease are diagnosed! There is no gender difference in prevalence. It is estimated that 1.6 million Americans who do not have celiac disease are on a gluten-free diet.

The clinical presentation can be divided into 4 clinical subcategories: classic disease, atypical disease, asymptomatic disease, and latent disease. Classic disease presents with diarrhea and malabsorption, weight loss, and vitamin or other nutrient deficiencies. The atypical presentation is much more common and signs/symptoms may include fatigue, anemia, arthritis, dental enamel defects, abnormal liver tests, osteoporosis, or infertility. Asymptomatic patients are recognized based on positive serology. Patients with latent disease manifest gluten-induced symptoms later in life.

Celiac disease has been associated with GI disorders including refractory reflux disease, eosinophilic esophagitis, recurrent pancreatitis, nonspecific transaminitis, irritable bowel syndrome, ulcerative colitis, and Crohn’s disease. Non-GI disorders associated with celiac disease include iron deficiency anemia, metabolic bone disease, peripheral neuropathy, and male and female infertility. The risk of small-bowel lymphoma is modestly increased in celiac disease.

Celiac disease is diagnosed by serological testing. Serological testing should be done while the patient is consuming a gluten-rich diet. Testing of patients on a gluten-free diet can result in false negative serology results. The most sensitive and specific tests are the tissue transglutaminase antibody (IgA) and anti-endomysial antibody (IgA). Anti-gliadin antibodies are no longer recommended. Measuring total IgA levels is important to exclude IgA deficiency which occurs with a higher incidence among patients with celiac disease. HLA genotyping can be helpful for patients in whom the diagnosis is equivocal. Ninety-nine (99%) percent of celiac patients have either the HLA-DQ2 and/or –DQ8 haplotype.

Serological Tests

• tissue transglutaminase [tTG] (IgA) OR
• anti-endomysial antibody (IgA)

AND

• total IgA

For equivocal cases:

• HLA-DQ2 and -DQ8

Patients with clinical features of celiac disease and/or patients with positive serology are recommended to undergo endoscopic biopsy to confirm the diagnosis. A low threshold for endoscopic referral is appropriate, even if serologic study results are negative because 10% of patients with celiac disease have negative serologic results.

Treatment for Celiac Disease is Lifelong Adherence to a Gluten-free Diet

Consultation with a dietician well-schooled in advising celiac patients is imperative. Fortunately, gluten-free foods are increasingly more common and good information resources are available.
For more information, visit celiac.org or contact us today.