ACG Clinical Guidelines: Diagnosis and Management of Celiac Disease

Abstract

This guideline presents recommendations for the diagnosis and management of patients with celiac disease. Celiac disease is an immune-based reaction to dietary gluten (storage protein for wheat, barley and rye) that primarily affects the small intestine in those with a genetic predisposition and resolves with exclusion of gluten from the diet. There has been a substantial increase in the prevalence of celiac disease over the last 50 years and an increase in the rate of diagnosis in the last 10 years. Celiac disease can present with many symptoms, including typical gastrointestinal symptoms (e.g. diarrhea, steatorrhea, weight loss, bloating, flatulence, abdominal pain) and also non-gastrointestinal abnormalities (e.g. abnormal liver function tests, iron deficiency anemia, bone disease, skin disorders, and many other protean manifestations). Indeed, many individuals with celiac disease may have no symptoms at all. Celiac disease is usually detected by serologic testing of celiac-specific antibodies. The diagnosis is confirmed by duodenal mucosal biopsies. Both serology and biopsy should be performed on a gluten-containing diet. The treatment for celiac disease is primarily a gluten-free diet (GFD), which requires significant patient education, motivation, and follow-up. Non-responsive celiac disease occurs frequently, particularly in those diagnosed in adulthood. Persistent or recurring symptoms should lead to a review of the patient’s original diagnosis to exclude alternative diagnoses, a review of the GFD to ensure there is no obvious gluten contamination, and serologic testing to confirm adherence with the GFD. In addition, evaluation for disorders associated with celiac disease that could cause persistent symptoms, such as microscopic colitis, pancreatic exocrine dysfunction, and complications of celiac disease, such as enteropathy-associated lymphoma or refractory celiac disease, should be entertained. Newer therapeutic modalities are being studied in clinical trials, but are not yet approved for use in practice. Given the incomplete response of many patients to a GFD free diet as well as the difficulty of adherence to the GFD over the long term, development of new effective therapies for symptom control and reversal of inflammation and organ damage are needed. The prevalence of celiac disease is increasing worldwide and many patients with celiac disease remain undiagnosed, highlighting the need for improved strategies in the future for the optimal detection of patients.

Diagnostic challenges in celiac disease

“…3,5 In IgA deficient patients, an IgG based test (anti-deamidatedgliadin peptide [DGP] IgG antibodies or TTG IgG antibodies) should be performed. 3 The most effective combination of immunoassays is TTG IgA and DGP IgG. 4 The antibody titers correspond with the degree of villous atrophy and in less destructive lesions are often lowlevel or negative.…”

“…5 False negative results may be associated with IgA deficiency, which is more common in CD patients than in the general population, since 2-3% of the patients are affected. 3 To ensure all patients with IgA deficiency are properly tested for CD it is recommended to either measure serum IgA level in all patients or include both IgA and IgG based testing. 3,5 In IgA deficient patients, an IgG based test (anti-deamidatedgliadin peptide [DGP] IgG antibodies or TTG IgG antibodies) should be performed.…”

“…3 To ensure all patients with IgA deficiency are properly tested for CD it is recommended to either measure serum IgA level in all patients or include both IgA and IgG based testing. 3,5 In IgA deficient patients, an IgG based test (anti-deamidatedgliadin peptide [DGP] IgG antibodies or TTG IgG antibodies) should be performed. 3 The most effective combination of immunoassays is TTG IgA and DGP IgG.…”

“…3,4 Another commonly used test is IgA anti-endomysial antibody (EMA), which is the most specific of all assays. 4 However, the latter test is technically more difficult, as it requires an immunofluorescence technique, which is a qualitative method; therefore, it is observer dependent and less objective.…”

Another Step Towards Celiac Screening

“…Currently, screening is recommended for individual patients who present with a symptom that could be a manifestation of celiac disease, or when indicated by family history or coincident medical conditions like type-1 diabetes mellitus or Down syndrome. 3 Ultimately, screening lies at the discretion of a clinician. Although screening with anti-tissue transglutaminase immunoglobulin A is considered both sensitive and specific, it is not the gold standard test, and being seropositive does not absolutely implicate mucosal disease; in this study, 16% of seropositive children who underwent endoscopy did not have celiac disease.…”