ZnT8 Autoantibodies Complement GAD and IA-2 Autoantibodies in the Identification and Characterization of Japanese Type 1 Diabetes.

AIM/INTRODUCTION: This study aimed to investigate the significance of zinc transporter 8 autoantibodies (ZnT8A) in identifying and characterizing autoimmune-mediated type 1 diabetes (T1D) in Japanese subjects. METHODS: ZnT8A were determined in 324 patients with T1D, 191 phenotypic type 2 diabetes (T2D), and 288 healthy control subjects using bridging-type enzyme-linked immunosorbent assay (ELISA) in addition to autoantibodies to glutamic acid decarboxylase (GADA) and insulinoma-associated antigen-2 (IA-2A). RESULTS: We set a cut-off value of 10.0U/mL, and twenty-five percent of the T1D patients had ZnT8A levels exceeding this level. The prevalence of ZnT8A was significantly higher in patients with acute-onset T1D than in those with slowly-progressive and fulminant T1D (P /=5 years (P 10 years (11.7% vs. 3.6%, P<0.05). Multivariate analysis revealed that ZnT8A positivity was independently associated with age at sampling and IA-2A positivity. CONCLUSION: These results suggest that the bridging-type ZnT8A ELISA may provide a valuable additional marker for Japanese patients with T1D, which could, in turn, allow for an increase in the number of identifiable cases and differentiate clinical phenotypes.