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

Abstract

Objective To explore the distribution characteristics of islet autoantibodies and other organ-specific autoantibodies in type 1 diabetes mellitus (T1DM) patients, and the correlation between organ-specific autoantibodies and clinical features. Methods A total of 205 newly diagnosed T1DM patients and 170 healthy controls were recruited in this study from the Second Xiangya Hospital of Central South University between Jan. 2015 and Dec. 2017. Glutamic acid decarboxylase antibody (GADA), insulinoma antigen 2 antibody (IA-2A), zinc transporter 8 antibody (ZnT8A) and other organ-specific autoantibodies, including thyroid peroxidase antibody (TPOA), thyroglobulin antibody (TGA), tissue transglutaminase antibody (tTGA) and 21-hydroxylase antibody (21-OHA) were detected by radioligand assay. In antibody-positive patients the function of thyroid and adrenal cortex was further examined; the coexistence of islet antibodies with other organ-specific autoantibodies, and the correlation between organ-specific antibodies and clinical characteristics were analyzed. Chi-square test, one-way analysis of variance and non-parametric test were used for statistical analysis. Results (1) The positive rates of GADA, IA-2A and ZnT8A in patients with T1DM were significantly higher than those in healthy controls [70.2% (144/205) vs 0.6%(1/170), 42.9%(88/205) vs 0 and 30.7%(63/205) vs 0 (0/170), χ2=190.131, 95.357, 62.792, respectively, all P 0.05). (3) In T1DM patients the detections of combining various islet autoantibodies (GADA+IA-2A+ZnT8A) could increase the positive rate to 82.9%. (4) T1DM patients with positive GADA and IA-2A were more likely to have positive TPOA and TGA antibodies, patients with positive IA-2A were more likely to have positive tTGA antibodies, and patients with two or more islet autoantibodies were more likely to have positive TPOA and TGA antibodies. (5) The proportion of T1DM patients with Graves′ disease was higher than that of healthy controls (4.4% vs 0.6%, P<0.05). Conclusions T1DM patients are prone to merge other organ-specific autoantibodies. It is of great clinical significance to screen other organ specific autoantibodies, especially in T1DM patients with positive polyantibodies. Key words: Diabetes mellitus, type 1; Islet autoantibody; Organ-specific autoantibody