The primary blood test for celiac disease is the tTG-IgA test, explains Celiac Disease Foundation. Patients may also undergo total serum IgA, deamidated gliadin peptide or IgA endomysial antibody testing to verify the results.
The tTG-IgA test, or tissue transglutaminase antibodies test, measures immunoglobulin A antibodies, also known as IgA, explains University of Rochester Medical Center. People with celiac disease often have an excess of immunoglobulin A antibodies.
However, some people with celiac disease have a natural deficiency of IgA, so they may need the total serum IgA test to verify the presence of celiac, says Celiac Disease Foundation. The deamidated gliadin peptide test, or DGP IgA and IgG test, is an additional way to detect the celiac disease in people who have antibody deficiencies. If patients prove difficult to diagnose with the other three tests, doctors may order the IgA endomysial antibody test.