yes it is possible. endomysial antibodies and anti-tissue transglutaminase antibodies (blood tests for diagnosing celiac disease) are highly reliable in diagnosing celiac disease. an individual with abnormally elevated endomysial and anti-tissue transglutaminase antibodies has a greater than 95% chance of having celiac disease. anti-gliadin antibodies are less reliable and have a higher rate of false positive tests. there are two recognized reasons for false negative blood tests for celiac disease: patients with deficiency of one type of antibody iga (they are born that way) will have low endomysial antibodies and anti-tissue transglutaminase antibodies since they are iga-type antibodies. patients who have self-treated themselves with a gluten-free diet for weeks to months before having these tests done can have abnormal blood tests revert to normal.
is it possible to have a false negative blood test for celiac disease?