Consistent dietary adherence in children and adolescents with celiac disease reflected in anti-tissue transglutaminase IgA and IgG: through diagnostic advancements and epidemiological challenges

BACKGROUND AND PURPOSE: Recent ESPGHAN guidelines permit the omission of duodenal biopsies in the diagnosis of celiac disease (CeD) in children with tTG-IgA≥10× upper limit of normal, regardless of clinical symptoms. This non-invasive approach may compromise dietary adherence through underestimating disease severity and questioning the diagnosis by families. We monitored serologic response in biopsy-based vs. no-biopsy cohorts using both tTG-IgA and tTG-IgG. A second aim was to investigate subjective and objective factors associated with dietary adherence, including during the period of the COVID restrictions. METHODS: Between 2020-2025, 190 children and adolescents with CeD were followed according to ESPGHAN guidelines. Biopsy-based and no-biopsy cohorts were compared in terms of clinical and demographic factors, laboratory results and dietary adherence. A targeted COVID-19 questionnaire was completed by 159 families. RESULTS: tTG-IgA levels normalized within 6 months in 55% of patients and after 12 months in 89%. tTG-IgG titers showed similar dynamics, with slightly faster early decline (74% normalized at 6 months), and were indispensable in 4 children (2.1%) with IgA deficiency. Antibody decline was comparable for the biopsy and no-biopsy groups. Only 13% of children exhibited nonadherence, mostly as a single episode. The no-biopsy group had a statistically higher incidence of anemia. The COVID-19 disease course was predominantly mild (94%), with gastrointestinal complications in 3 cases. The perceived impact of COVID-19-related lockdown on dietary adherence was self-reported as neutral in 65% and positive in 26% of families. CONCLUSIONS: The no-biopsy approach sustained excellent antibody normalization rates, as measured by both tTG-IgA and tTG-IgG. Nonadherence was rare and mostly associated with adolescence, peer influence, challenged family/social structure, limited parental supervision, poor choice of school meals, and comorbidities. The importance of targeted educational interventions and follow-up is emphasized.