Exploring Tissue Transglutaminase Antibodies as a Confirmatory Tool for Diagnosing Coeliac Disease in Children.

Background/Objectives: The prerequisite for diagnosing celiac disease (CD) in children without duodenal biopsy is a tissue transglutaminase antibody (TGA) level exceeding 10 times the upper limit of normal levels, along with a positive confirmatory anti-endomysial antibody (EMA) test in a secondary blood sample. The aim of our study was to determine whether determination of TGA in a second blood sample could be as reliable as determination of EMA as the confirmatory test in children eligible for the no-biopsy approach. Methods: A retrospective analysis of medical data was conducted, including children under 19 years old who were diagnosed with coeliac disease at our department from January 2013 to June 2025. We examined the diagnostic process, focusing on TGA levels at the time of diagnosis. Results: Data from 185 CD patients (59.5% female, median age 8 years) were available for the analysis. 49 (26.5%) patients were diagnosed using no-biopsy approach and 46 (93.9%) of those had TGA > 10 × ULN in second blood sample as well. In the group of children diagnosed using duodenal biopsy (N = 136; 96.3% 3 Marsh), 78 (57.4%) children had initial TGA > 10 × ULN. In 34 (43.6%) of those children, secondary serology performed before introducing a diet showed that 30 (88.2%) of them had TGA > 10 × ULN. Conclusions: Our study suggests that TGA levels > 10 × ULN could serve as a reliable test for confirming the diagnosis of CD in children, eligible for the no-biopsy approach, thus making the diagnostic process more cost-effective and efficient, while maintaining accuracy.