Autoimmune thyroid disease correlates to islet autoimmunity on zinc transporter 8 autoantibody

Abstract

bjective: The most common coexisting organ-specific autoimmune disease in patients with type 1 diabetes mellitus (T1DM) is autoimmune thyroid dise ase (AITD). However, there have been few clinical reports based on a large populatio n about the prevalence of zinc transporter 8 autoantibody (ZnT8A) and other islet auto antibodies in AITD patients. We aimed to explore the presence of islet autoantibod ies, ZnT8A, glutamic acid decarboxylase autoantibodies (GADA) and insulinoma-associated antigen 2 autoantibodies (IA-2A) compared with thyroid autoantibodies, thyroid peroxidase autoantibodies (TPOAb) and thyroglobulin autoantibodies (TGAb) and thyrotropin receptor autoantibodies (TRAb) in patients with Graves’ disease (GD), Hashimoto’s thyroiditis (HT) and T1DM patients with AITD. Methods: Totally, 389 patients with GD, 334 patients with HT, 108 T1DM patients with AITD and 115 healthy controls (HC) were recruited in the study. Islet autoantibodies (ZnT8A, GADA and IA-2A) were detected by radioligand binding as say. Thyroid autoantibodies, TPOAb and TGAb were detected by chemiluminescen ce assay, and TRAb was detected by RIA. Results: The prevalence of ZnT8A, GADA and IA-2A was higher in GD and H T patients than that of HC (ZnT8A: GD 8.48%, HT 10.8% vs HC 1.74%; GADA: GD 7.4 6%, HT 7.74% vs HC 0.870%; IA-2A: GD 4.88%, HT 3.59% vs HC 0%; All P < 0.05) but lower than that of T1DM subjects with AITD (ZnT8A: 42.6%; IA-2A: 44.4%; GADA: 74.1%; al l P < 0.0001). Conclusions: An increased prevalence of ZnT8A as well as GADA and IA-2A was found in both GD and HT patients, indicating that there is a potentia l link between thyroid autoimmunity and islet autoimmunity.

Keywords

• autoimmune thyroid disease
• type 1 diabetes mellitus
• zinc transporter 8 autoantibody
• thyroid peroxidase autoantibodies