<<Disclaimer: Verify this information before applying it to your situation.>> Hi Michael, The period that one of the GI specialists here in town requires is three months prior to an endoscopy. The antibody tests, as I understand them, measure the quantity of antibodies in a given volume of blood. Dylan's body would stop producing antibodies to gluten, if he had stopped eating gluten. I am not a health professional, but a test when Dylan had been gluten-free until one week prior to the blood being taken seems less meaningful that one taken after a substantial period of gluten ingestion. I am sure a celpro will be able to give you a clearer explanation, and I hope someone will. Best Wishes, Ron Hoggan