To the Editor We read with interest the article by the Environmental Determinants of Diabetes in the Young (TEDDY) Study Group about evidence of antibiotic use influencing the risk of type 1 diabetes or celiac disease (CD)–related autoimmunity in the first 4 years of life in a genetically at-risk population.1
However, CD autoimmunity was screened by testing only for tissue transglutaminase (TTG) autoantibodies in children between ages 12 months and 48 months, omitting the growing utility of deamidated gliadin peptide (DGP) testing, especially in the setting of a negative TTG IgA test result.