Testing for anti-human transglutaminase antibodies in saliva is not useful for diagnosis of celiac disease.

Abstract

Undetected celiac disease (CD) can cause serious complications and excessive mortality (1)(2)(3). Noninvasive tests could be useful in physicians’ offices to identify patients for intestinal biopsies (4). Serum IgA anti-endomysium (AEA) and anti-human transglutaminase (anti-htTG) antibody assays are the most widely used laboratory tests for CD (5). Autoantibody determinations have been simplified by the use of rapid testing (6)(7), but when saliva specimens were evaluated for AEA testing, they were found to be not suitable (8). To evaluate the potential utility of saliva as a sample for anti-htTG testing, we compared salivary IgA anti-htTG (measured by ELISA with a dot-blot method and an AEA test) with serum IgA anti-htTG antibodies (measured by ELISA and an AEA test) in patients with CD and in controls. Salivary IgA anti-htTG activity was analyzed for the IgA secretory chain by use of a monoclonal antibody. The recognition patterns of the saliva samples were compared with those for the serum samples and with the pattern for a gut-derived IgA monoclonal antibody to htTG from one CD patient, using two transglutaminase deletion mutants, one recognized and one not by the patients’ sera (9). We studied 47 untreated CD patients (29 females and 18 males; median age, 19 years; range, 2–52 years) diagnosed in 2002–2003 according to ESPGHAN criteria (10) and 47 patients with celiac disease (26 females and 21 males; median age, 19 years; range, 4–50 years) on a gluten-free diet (GFD) for at least 12 months. We recruited 51 healthy controls with no history of gastrointestinal or autoimmune diseases (25 females and 26 males; median age, 14 years; range, 6–50 years) and identified samples from 49 individuals suffering from various gastrointestinal diseases (18 with Crohn disease, 10 with ulcerative colitis, 10 with milk allergy, 6 with acute …