Type 1 diabetes and other autoimmune diseases : epidemiology, pathophysiology and screening

Abstract

Introduction: The interplay between type 1 diabetes (T1D) and concomitant autoimmune diseases (AID) is both clinically and scientifically relevant. In this review, we delineate the epidemiological, pathophysiological and practical aspects underlying polyautoimmunity with a focus on T1D. Method: A comprehensive review of literature on T1D and associated AID was conducted, with the aim of drawing informed conclusions relevant to clinical practice. It draws on a targeted PubMed search conducted March–May 2025, emphasising recent peer-reviewed articles in English. Results: Epidemiological data consistently indicate that individuals with T1D exhibit a significantly increased prevalence of additional AID. Familial aggregation of discordant AID and the concept of polyglandular autoimmune syndromes (PAS) or autoimmune polyendocrinopathy highlight that multiple AID can cluster and occur in a sequential and overlapping fashion, with T1D frequently acting as either an early or a subsequent manifestation. Thereby, genetic susceptibility, environmental triggers and epigenetic factors are pivotal in the initiation and progression of autoimmunity. Clinically, the coexistence of T1D with other AID poses significant challenges in disease management, often necessitating adjustments in therapeutic regimens and careful monitoring to mitigate complications. Early detection via stratified autoantibody testing is important for timely intervention and improved long-term outcomes. Conclusions: Accordingly, screening for T1D-associated autoantibodies in individuals with a personal or family history of AIDs, and vice versa, should be implemented in clinical practice.