Organ-specific autoantibodies in Chinese patients newly diagnosed with type 1 diabetes mellitus

Abstract

This study aims to investigate the prevalence of islet autoantibodies and other organ-specific autoantibodies in type 1 diabetes mellitus (T1DM) patients and characterize their clinical features. Glutamic acid decarboxylase antibody (GADA), insulinoma antigen 2 antibody (IA-2A), zinc transporter 8 antibody (ZnT8A) and tetraspanin7 antibody (TSPAN7A) were assayed by radioligand or luciferase immunoprecipitation system assays in 205 newly diagnosed acute-onset T1DM patients and 170 healthy controls. Other organ-specific autoantibodies, including thyroid peroxidase antibody (TPOA), thyroglobulin antibody (TGA), tissue transglutaminase antibody (tTGA) and 21-hydroxylase antibody (21-OHA), were also measured. The prevalence of GADA, IA-2A, ZnT8A, TSPAN7A, TPOA, TGA and 21-OHA was higher in T1DM patients than in healthy controls. The combinational assay of various islet autoantibodies could increase the frequency of autoantibody positivity in T1DM to 85.4%. GADA+ IA-2A+ T1DM patients preferentially had TPOA and TGA, while IA-2A+ patients often had tTGA. Patients positive for two or more islet autoantibodies often had TPOA and TGA. BMI of multiple islet autoantibody-positive patients was lower than that of patients with single or no islet autoantibodies, and there were no significant differences in C-peptide and glycated hemoglobin between patients positive for islet autoantibodies combined with other organ-specific antibodies and noncombined patients. Younger female patients who were islet autoantibody positive were more likely to have TPOA and TGA. The frequency of Graves’ disease was much higher in T1DM patients than in healthy controls. T1DM usually occurs together with other organ-specific autoantibodies. Measuring of other organ-specific autoantibodies will be beneficial for T1DM patients.