Yes, it’s possible to get a false negative during a celiac blood test. There are two major reasons for this. Patients with a deficiency of one type of antibody, IgA will have low endomysial antibodies and anti-tissue transglutaminase antibodies can show false negative tests. Similarly, those who’ve refrained from including gluten in their diet and have followed a gluten-free diet for more than a week will show a negative celiac blood test.