Autoimmune polyglandular syndromes (APS) are conditions characterized by the association of two or more endocrine and non-endocrine autoimmune disorders. Diabetes mellitus type 1 (T1DM) is one of the most frequent components of APS and is often its first symptom. The frequency of autoimmune pathologies in patients affected by T1DM is proportional to the persistance of ICA. Even in first relatives of these patients, an increase in incidence of latent or manifest autoimmune pathology is noticed. The association of T1DM with autoimmune thyroiditis and celiac disease in a girl from a family affected by high incidence of autoimmune pathology is described. The role of gluten in the pathogenesis of T1DM and some other autoimmune conditions in genetically predisposed subjects. Infact studies are still inadequate for demostrating how a gluten-free diet could delay or mitigate the course of T1DM and of other autoimmune pathologies in genetically predisposed subjects. Nevertheless, it is suggested that gluten could represent a starting or a maintenance factor of autoimmune processes and the risk of autoimmune pathologies is proportional to the duration of the exposure to gluten. A screening for a quick singling out of autoimmune pathologies is suggested for T1DM patients, their first relatives and for subjects affected by other autoimmune diseases or celiac disease.