Type 1 diabetes mellitus is an autoimmune disease in which patients with a genetic predisposition develop antibodies against pancreatic islet β-cells under certain conditions, resulting in the loss of insulin production. Genetic, infective, dietary, and humoral factors are potential predictors associated with the risk of β-cell destruction. The coexistence of another autoimmune disease can be found in up to 29% of patients with type 1 diabetes. The most common disorders are autoimmune thyroid disease, coeliac disease, autoimmune gastritis, pernicious anaemia, and vitiligo. Other conditions that can coexist with type 1 diabetes are rheumatoid arthritis, autoimmune hepatitis, alopecia, and psoriasis. This coexistence is often present in autoimmune polyendocrine syndromes. The likelihood of developing an autoimmune disease increases with age, and it is higher in the female population. Concomitant autoimmune diseases can negatively affect the patient’s quality of life and metabolic control of diabetes, potentially increasing the risk of micro- or macrovascular complications and the frequency of hypoglycaemic episodes. Determining organ-specific antibodies is useful in the active search for autoimmune diseases in type 1 diabetes patients to identify individuals at increased risk for the disease. This article aims to summarise the most recent research on type 1 diabetes-associated autoimmune disorders, including screening, diagnosis, and treatment principles.

autoimmune thyroid diseases, type 1 diabetes mellitus, autoimmune disorders, coeliac disease