Type 1 diabetes and celiac disease: Clinical overlap and new insights into disease pathogenesis

Type 1 diabetes (T1D) and celiac disease (CD) are autoimmune diseases with clinical and pathogenic overlap. The mean prevalence of CD in patients with T1D is about 8 %. Classic intestinal symptoms of CD may not be present in T1D leading to the recommendation for active case finding in this higher risk group. Screening is done with sensitive and specific serologies including tissue transglutaminase (tTG) IgA and deaminated gliadin peptide (DGP) IgA and IgG. Positive serologies are confirmed by the presence of villous atrophy and increased intraepithelial lymphocytes on duodenal biopsy. A strict gluten free diet is recommended, although this can pose challenges for T1D patients who already have dietary restrictions. In aggregate, it appears as if the gluten free diet may help T1D management. T1D and CD have overlapping genetic and environmental risk factors. Among these, non-HLA genetic factors and the gut microbiome are among recent developments that will be discussed in this review.