serologic diagnosis

Celiac disease is an autoimmune disease that can occur through the lifespan and is characterized by immune-mediated enteropathy in response to dietary gluten.1 Celiac disease affects at least 1% of the global population. Important risk factors are a first-degree relative with celiac disease, carrying specific genetic variants, presence of other autoimmune conditions (eg, type 1 diabetes, Hashimoto thyroiditis), and certain chromosomal disorders (eg, Down syndrome, Turner syndrome, Williams syndrome).

Typical gastrointestinal symptoms include diarrhea (38%), abdominal discomfort (34%), and weight loss from malabsorption (16%).2 Subjective improvement in symptoms with a gluten-free diet has a poor positive predictive value (PPV) for celiac disease (36%), making objective testing essential. Diagnostic guidelines (Table) recommend performing serologic testing in individuals with symptoms and/or signs suggestive of celiac disease while they are consuming a diet containing gluten, which is present in wheat, barley, and rye. Gluten reduction or removal from the diet impairs the diagnostic accuracy of screening.3-7 For patients already following a gluten-free diet, gluten consumption must be resumed prior to screening. However, there is no consensus for the dose or duration of gluten consumption that should be maintained through second confirmatory tests. Of the 2 most recent guidelines, one does not specify a dose or duration4 and one suggests at least 3 g per day for at least 6 weeks.3