Type 1 diabetes and associated autoimmune diseases

BACKGROUND: Common autoimmune diseases (AID) tend to occur together in the same individual and families. Type 1 diabetes (T1D) is caused by an autoimmune-induced inflammatory destruction of the pancreatic tissue and clusters with several other AID. AIM: To compare the demographic, clinical, and serological features of patients with single T1D vs those with T1D and associated AID. METHODS: From October 1999 to February 2020, a total of 665 patients with T1D and their first-degree relatives were evaluated. RESULTS: Compared to patients with isolated T1D, those with T1D + AID were older and had a higher female: male ratio. Average patient age and age at disease onset were higher in T1D + AID vs T1D only. The average time interval between T1D onset and the onset of a second glandular AID was markedly shorter than the time interval between T1D and the occurrence of a non-endocrine AID. T1D-specific autoantibodies were more frequent in patients with T1D + AID and relatives vs those with T1D only. However, the prevalence of AID and autoantibodies against various tissues were found to be higher in relatives of patients with T1D only compared to relatives of patients with T1D + AID. CONCLUSION: Annual serological and subsequent functional screening for AID in patients with T1D and their first-degree relatives is recommended.