From the Guidelines
A celiac panel is a crucial diagnostic tool for identifying celiac disease, and it should include testing for tissue transglutaminase antibodies (tTG-IgA) and total IgA levels, with additional tests such as deamidated gliadin peptide antibodies (DGP-IgA and DGP-IgG) and endomysial antibodies (EMA-IgA) as needed, as recommended by the most recent and highest quality study 1. The celiac panel is used to screen for celiac disease, an autoimmune disorder triggered by gluten consumption.
- The panel typically includes testing for tissue transglutaminase antibodies (tTG-IgA), which is the most sensitive and specific test, along with total IgA levels to ensure the patient can produce enough IgA for accurate results.
- Additional tests may include deamidated gliadin peptide antibodies (DGP-IgA and DGP-IgG) and endomysial antibodies (EMA-IgA).
- For accurate results, patients should continue consuming gluten before testing, as eliminating gluten can lead to false negatives.
- If the panel shows positive results, a small intestine biopsy is usually recommended to confirm the diagnosis, although some guidelines suggest that biopsy-avoidance strategies may be suitable for certain patients, such as children with high tTG-IgA levels and positive EMA results 1. The test is recommended for individuals with symptoms like chronic diarrhea, abdominal pain, unexplained weight loss, or those with first-degree relatives who have celiac disease.
- Early diagnosis is important as untreated celiac disease can lead to nutritional deficiencies, osteoporosis, infertility, and increased risk of certain cancers.
- The treatment of celiac disease is a lifelong and strict gluten-free diet, which can be challenging to maintain, but is essential for managing the condition and preventing long-term complications 1.
From the Research
Celiac Panel Overview
- A celiac panel is a series of tests used to diagnose celiac disease, an immune-mediated disorder that affects genetically susceptible individuals who are exposed to gluten-containing grains 2.
- The tests included in a celiac panel may vary, but common tests include:
- Immunoglobulin A (IgA) tissue transglutaminase (tTG) antibody test
- Immunoglobulin A (IgA) endomysial antibody (EMA) test
- Immunoglobulin G (IgG) anti-gliadin antibody test
- Intestinal biopsy
Diagnostic Criteria
- The IgA tTG antibody test is the recommended initial screening for all age groups 2.
- A positive result on the IgA tTG antibody test, combined with a positive result on the IgA EMA test, has a positive predictive value of nearly 100% for celiac disease 3.
- An anti-TTG ratio ≥ 7 can identify patients with significant mucosal damage (Marsh ≥ 2) independent of age and sex, with a specificity and positive predictive value of 100% 3.
- An anti-TTG ratio >20 is more specific (99.8%) for identification of patients with villous atrophy (Marsh 3 a, b, or c) 3.
Test Characteristics
- The IgA tTG antibody test has a high sensitivity and specificity for celiac disease, but the sensitivity may decrease after dietary restriction 4.
- The IgG anti-gliadin antibody test is more sensitive than the IgA anti-gliadin antibody test, but less specific 5.
- The IgA EMA test is highly specific for celiac disease, but may not be as sensitive as the IgA tTG antibody test 5.
- Different assays for measuring tTG-IgA may have different characteristics, and normalization of antibody levels may depend on the assay used 6.
Clinical Application
- A celiac panel can be used to diagnose celiac disease in patients with symptoms such as diarrhea, weight loss, abdominal pain, and bloating 2.
- A celiac panel can also be used to monitor patients with celiac disease on a gluten-free diet, although the choice of assay may affect the results 6.
- In some cases, a duodenal biopsy may be avoided if the patient has a high pretest probability of celiac disease and a positive result on the IgA tTG antibody test and IgA EMA test 3.