I have a patient who may be gluten intolerant. What should I do?
What test do I order to screen for celiac disease?
- Tissue transglutaminase IgA antibody
- Total IgA (quantitative level)
A “celiac panel” is NOT recommended. An anti-endomysial antibody test could be ordered instead of tissue transglutaminase.
How do I interpret a positive test for anti-gliadin antibodies?
These tests are not well standardized, so interpreting the results may be difficult. A positive IgG anti-gliadin antibody is found in about 30% or more of normal individuals, and indicates gliadin in the diet. It is also positive in individuals with celiac disease. It is sensitive, but not specific. A positive IgA anti-gliadin is more sensitive and specific for celiac disease, but tissue transglutaminase is clearly better.
Is a biopsy mandatory for making a diagnosis of celiac disease?
We still recommend a biopsy to confirm the diagnosis of celiac disease. We will NOT make the diagnosis without biopsy confirmation. It is important to know that the biopsy excludes other causes for the signs or symptoms. In fact, about 5% of cases in which the patient and the physician feel celiac disease is present, actually have other explanations for the signs or symptoms. Celiac disease may be present in some of these patients, but asymptomatic. In addition, false positive screening tests (especially with anti-gliadin antibody tests) are common, so the biopsy is needed for disease confirmation and starting a life-long gluten free diet.
What follow-up is needed after the diagnosis?
- Annual follow-up with PCP and dietician, and every 2-3 years with celiac specialist is recommended.
- Growth, nutritional status, adherence to diet should be monitored.
- Assess for improvement in anemia, specific nutrient deficiencies.
- Monitor adherence with tissue transglutaminase antibody at least yearly.
- If adherence to diet is poor, review bone density and malignancy risks with the family and patient.
- Once patient reaches adolescence, consider a bone mineral density assessment (DEXA scan).
Should family members be screened?
First-degree family members should be screened once for Tissue Transglutaminase IgA and total IgA. If repeatedly positive, an intestinal biopsy should be performed before starting the relative on a gluten-free diet. If negative, re-screening should be done if symptoms develop during childhood or during adulthood.