Delayed normalization of tissue transglutaminase antibodies in children with celiac disease and type 1 diabetes mellitus

OBJECTIVES: Diabetes mellitus type 1 (T1DM1) and celiac disease (CD) can coexist in a patient. The aim was to evaluate the characteristics of children with both CD and T1DM and children with CD alone and to compare normalization rates of tissue transglutaminase immunoglobulin A class antibodies (anti-tTG IgA) normalization. METHODS: This retrospective longitudinal study included children with both T1DM and CD and children with CD alone found by family screening, followed up from 2013 to 2023. Anthropometric and serologic parameters were evaluated at the time of diagnosis and during follow-up. RESULTS: Included were 18 patients in T1DM + CD group (39% girls, median age 8.9 years) and 27 patients in CD group (52% girls, median age 8.8 years). There were no statistically significant differences in gender, age, anthropometry parameters, frequency of patients with initial anti-tTG levels >10 times of upper limit of normal (78% vs. 63%, p > 0.05), frequency of follow-up visits (1.06 visits/year of follow-up vs. 0.76, p > 0.05) and follow-up period (4.3 vs. 3.89 years, p > 0.05). The only statistically significant difference was in timing of anti-tTG normalization. At 2 years after diagnosis anti-tTG normalized in 56% of patients in T1DM1 + CD versus 93% in CD alone group (p < 0.01). If only patients with high antibody titers were analyzed, the normalization was still slower in CD + T1DM group (p < 0.05). CONCLUSIONS: It takes longer to normalize anti-tTG in children with coexisting T1DM and CD than in CD alone found by family screening. We suggest monitoring these patients more closely during the first years after the diagnosis of CD.