<<Disclaimer: Verify this information before applying it to your situation.>> RAST testing is indicated in situations where one is allergic and the reactions are prompted soon after intake of the allergen. In your situation, the doctor is thinking that your son may have an allergic response to gluten. The type of antibody in allergic reactions is IgG. The other possibility in your situation is that your son may have gluten sensitive enteropathy (celiac disease). This disease is manifested by the presence of anti-gliadin, anti-endomysial, and anti-reticulin antibodies. I do not understnad why the latter group of tests are inconclusive. If I can get the results, I might be able to provide further information. You may want these tests repeated in another laboratory that specializes in this such tests. Vijay Kumar, Ph.D. Research Associate Professor