Algorithm for diagnosis of celiac disease in children

tTG-IgA: IgA antibodies to tissue transglutaminase; IgA: immunoglobulin A; DGP: deamidated gliadin peptide; IgG: immunoglobulin G; HLA: human leukocyte antigen; ULN: upper limit of normal; EMA: anti-endomysial antibodies.

* Gastrointestinal symptoms that raise the possibility of celiac disease include persistent diarrhea, poor weight gain, abdominal pain, constipation, and/or vomiting. Extraintestinal symptoms include neurologic and behavioral symptoms, arthritis, abnormal liver biochemical tests, and/or a dermatitis herpetiformis-like rash. For details, refer to UpToDate content on celiac disease in children.

¶ The following groups are at increased risk for celiac disease and warrant screening: children with first-degree relatives with celiac disease and children with autoimmune thyroiditis, type 1 diabetes, autoimmune liver disease, juvenile chronic arthritis, Down syndrome, Turner syndrome, Williams syndrome, or selective IgA deficiency.

Δ The most valuable test is tTG-IgA, which is highly sensitive, specific, and more cost-effective than other antibody tests. For patients with IgA deficiency, we suggest measurement of tTG-IgG and DGP-IgG.

◊ Antibody testing should be performed while on a gluten-containing diet (ideally at least 10 g gluten/day for 8 to 12 weeks). Serologies may become negative within weeks of beginning a gluten-free diet but may persist for more than 1 year. For patients who are already on a gluten-free diet, a negative result of an antibody test cannot exclude celiac disease.

§ The decision to use biopsy versus a serologic approach for patients with high tTG-IgA titers should be individualized to the patient's and family's values and preferences, informed by the provider's clinical suspicion for celiac disease and coexisting gastrointestinal pathology. Details and specific considerations are outlined in the UpToDate content on diagnosis of celiac disease in children.

¥ HLA testing has very limited value in an evaluation for celiac disease. Although virtually all individuals with celiac disease have either HLA-DQ2 or DQ8 haplotypes, this is also the case for approximately 40% of the general population. Moreover, these HLA types are particularly common among members of groups at high risk for celiac disease (eg, first-degree relatives of patients with celiac disease or patients with autoimmune diseases). Thus, the presence of HLA-DQ2 or DQ8 is not informative, while the absence of these haplotypes virtually excludes celiac disease. HLA testing is no longer required for a nonbiopsy diagnosis.