Islet Autoantibodies in Adult With Pituitary and Ovarian Autoimmunity: Implications for Type 1 Diabetes Screening

Purpose: Type 1 diabetes is a chronic autoimmune disease characterised by progressive pancreatic β-cell destruction and the early appearance of islet autoantibodies (islet-AAb) during the pre-symptomatic phases. Given the growing interest in screening and prevention of type 1 diabetes, this study aimed to assess the prevalence of pancreatic autoimmunity in adults with other organ-specific autoantibodies in order to identify potential target populations for screening programs. Methods: Adults previously tested for autoantibodies against specific endocrine glands and/or gastric parietal cells by indirect immunofluorescence were divided into two groups (Autoimmunity group and Control group), according to the presence of at least one organ-specific autoantibody. Stored serum samples from all participants were re-evaluated for islet-AAb and comparisons were performed between groups and, within the Autoimmunity group (Group A), across different patterns of organ-specific autoimmunity. Results: Positivity for at least one islet-AAb was significantly higher in Group A than in Control Group (40.3% vs. 21.0%; p = 0.007). Double and triple islet-AAb positivity were less common overall, but occurred more frequently in Group A. Moreover, in Group A, a significantly higher prevalence of multiple positivity (≥ 2 islet-AAb) was observed in subjects with ovarian autoimmunity and in those with combined pituitary and ovarian autoimmunity than in those with other endocrine autoimmune involvement. Conclusion: Adults with specific autoimmunity disorders, particularly those affecting ovarian and/or pituitary glands, have a higher prevalence of pancreatic autoimmunity. These subjects may benefit from targeted screening to identify the pre-symptomatic stage of T1D and potentially delay progression to clinical disease.