Long-term persistence of markers of autoimmune β-cell destruction and residual C-peptide secretion in patients from a South American cohort with type 1 diabetes mellitus

Introduction . It was previously believed that markers of the autoimmune process, specifically autoantibodies ( Abs ) against β cells in patients with type 1 diabetes mellitus (DM1), persist only during the first 5 years of the disease. Contrary to established opinion, some patients with long- term T1D showed elevated levels of markers of autoimmune β-cell destruction as well as residual insulin secretory function, determined by fasting C-peptide level. According to various sources, the prevalence of this type of observations ranges between 12 and 48%.