Normalisation of antibody levels with gluten-free diet introduction for Celiac Disease

Dear Ask The Doctor: A number of months back I was informed that going on a gluten free died would make my uncontrollable hyperthyroidism disapear. Without consulting my doctor I went and did it. It was the best choice I ever did, I felt 100 times better, and I had stopped taking my thyroid meds. To make sure I did have Celiac disease I asked my doctor to test for it. Which he did, he also tested for my T4 levels. When he called me back to tell me the results, he told me that I did not have Celiac disease but that my hyperthyroidism was in remission. Did it not show up that I had Celiac Disease because I had stopped eating gluten a number of months back or was it a placebo effect?

Dear Giuliana: Diagnosis of celiac disease is based on relevant clinical symptoms and positive laboratory investigations. These laboratory investigations usually include Immunoglobulin A (IgA) antitissue transglutaminase antibodies and IgA antiendomysial antibodies, which are highly sensitive and specific in diagnosing celiac disease. The presence of circulating celiac-disease-associated antibodies at the time of diagnosis and their normalization after a gluten-free diet support a diagnosis of celiac disease. Therefore if your investigations were completed after you had commenced a gluten-free diet for a number of months, they may be normal, even though you have Celiac disease. It is important to inform your family physician that you had already commenced a gluten-free diet at the time of testing.