Which blood tests show high concordance for detecting Celiac disease autoantibodies?
When screening for celiac disease, doctors often use blood tests that look for specific autoantibodies. Two tests — anti-tissue transglutaminase (tTG) IgA and anti-endomysial antibody (EMA) IgA — are considered highly reliable. Studies show that these two tests agree with each other in the vast majority of cases, making them a strong combination for diagnosis.
What the research says
A study in a Tunisian cohort found that an indirect immunofluorescence test (IIFT) detected anti-endomysium IgA antibodies in 100% of celiac patients, while ELISA for tTG IgA and deamidated gliadin peptide (DGP) antibodies also showed 100% positivity in the same group 6. This suggests near-perfect concordance between these methods in that population.
Another study in Indian children reported that tTG antibody testing had 94% sensitivity and 97% specificity, with a 95% concordance with EMA in celiac cases and 97.5% in controls 10. This high agreement supports using tTG as a reliable first-line test.
A population-based screening study (UNISCREEN) used a novel luciferase immunoprecipitation system (LIPS) assay for tTG IgA and found it feasible for large-scale screening, with capillary blood samples showing good concordance with confirmatory venous samples 8. This indicates that newer assay formats also maintain high agreement with established methods.
Earlier research also showed that EMA and anti-gliadin antibody tests had high efficiency, with concordant results in 220 of 259 samples (85%) 9. While anti-gliadin tests are less specific, the combination of tTG and EMA remains the most concordant pair.
What to ask your doctor
- Should I have both tTG IgA and EMA tests, or is one sufficient for screening?
- If my tTG IgA is positive, do I still need an EMA test to confirm?
- Are there any situations where these tests might not agree, such as in IgA deficiency?
- How do newer blood test methods (like LIPS) compare with standard ELISA for accuracy?
- If my blood tests are positive, what is the next step — do I need a biopsy?
This question is drawn from common patient questions about Hematology and answered using cited medical research. We do not provide individualized advice.