(23) No difference in thyroid or celiac disease prevalence in children with antibody positive and negative type 1 diabetes

Background: Type 1 Diabetes Mellitus (T1D) results from an autoimmune destruction of pancreatic β-cells, leading to absolute insulin deficiency. Individuals with T1D are at increased risk for other autoimmune disorders, such as autoimmune thyroid disease (ATD) and celiac disease (CD). While most T1D patients have β-cell autoantibodies, approximately 5-10% do not, classifying them as idiopathic T1D. It is unknown whether the rates of other autoimmune diseases is different between the two types of T1D.

Objectives: To compare the prevalence and distribution of autoimmune diseases association (celiac disease or hypo- or hyperthyroidism) with idiopathic T1D compared with T1D with circulating islet autoantibodies.

Design/Methods: We retrospectively reviewed medical charts of children aged 6 months to 18 years diagnosed with T1D between January 2010 and June 2023 with subsequent long term insulin requirement. The cohort was divided into two groups based on the presence (AB+) or absence (AB-) of islet cell antigen, insulin, GAD-65, or Zinc transporter 8 autoantibodies at diagnosis. For each AB- patiente we included two age- and sex-matched AB+ patients, diagnosed within 2 years as controls.

Results: Of the 149 cases with AB- T1D, 9 had CD and/or ATD, while among 298 patients with AB+, 26 had one or both conditions (p=0.319). Additionally, 5 of 149 AB- and 15 of 298 AB+ patients had CD. (p = 0.419). ATD was present in, 4 of 149 AB- children, and 13 of 298 children with AB+, (p=0.382).

Conclusion: This study demonstrates no significant difference in the prevalence of autoimmune diseases between patients with idiopathic T1D and those with β-cell autoantibodies positive T1D. These findings imply that idiopathic T1D is likely still autoimmune in nature. Therefore, surveillance methods for autoimmune diseases should not differ between idiopathic T1D and antibody positive T1D.