is a blood test necessary for celiac disease
1 Anti-tTG, IgA is the most sensitive and specific blood test for celiac disease. 2  The IgG class of anti-tTG may be ordered for people who have a deficiency of IgA. 3  Quantitative immunoglobulin A (IgA) : measures the total level of IgA in the blood to determine if someone is deficient in the IgA class of antibodies.