The Gliadin Antibody IgM test is a blood test that measures the level of IgM antibodies in response to gliadin, a protein found in gluten. Gliadin is found in wheat, barley, and rye, and can cause an immune response in people with celiac disease or gluten sensitivity. The Gliadin Antibody IgM test is used to help diagnose celiac disease and monitor the effectiveness of treatment. IgM antibodies are the first antibodies to be produced in response to an antigen, and elevated levels of IgM antibodies to gliadin may indicate an active immune response to gluten. The test is done by drawing a blood sample from a vein and is a simple and relatively non-invasive procedure. A positive Gliadin Antibody IgM test, along with other diagnostic criteria, may require further testing or evaluation by a healthcare provider.