Journal of Diabetes Investigation (Apr 2021)

Different interaction of onset age and duration of type 1 diabetes on the dynamics of autoantibodies to insulinoma‐associated antigen‐2 and zinc transporter 8

  • Eiji Kawasaki,
  • Yoichi Oikawa,
  • Akira Okada,
  • Norio Kanatsuna,
  • Tomoyuki Kawamura,
  • Tadashi Kikuchi,
  • Jungo Terasaki,
  • Junnosuke Miura,
  • Yoshihisa Itoh,
  • Toshiaki Hanafusa

DOI
https://doi.org/10.1111/jdi.13370
Journal volume & issue
Vol. 12, no. 4
pp. 510 – 515

Abstract

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Abstract Aims/Introduction This study aimed to investigate the dynamics associated with autoantibodies to insulinoma‐associated antigen‐2 (IA‐2A) and zinc transporter 8 (ZnT8A) relating to the onset age and disease duration in patients with type 1 diabetes. Methods Using bridging‐type enzyme‐linked immunosorbent assay, IA‐2A, ZnT8A and glutamic acid decarboxylase autoantibodies were evaluated in 269 patients with type 1 diabetes (median onset age 18.2 years, range 0.8–86 years; median diabetes duration 7 years, range 0–58 years). We then compared the prevalence of these autoantibodies among the different age groups, along with the duration of diabetes using the Cochran–Armitage trend test and multivariate logistic regression analysis. Results The prevalence of IA‐2A, ZnT8A and glutamic acid decarboxylase autoantibodies in patients with duration of ≤3 years was 41.1, 36.7 and 72.2%, respectively, with 80.0% expressing one or more of these autoantibodies. This prevalence declined according to the disease duration (P < 0.005). Both IA‐2A and ZnT8A were more frequently observed in younger patients, whereas glutamic acid decarboxylase autoantibodies was more common in older patients. Multivariate logistic regression analysis showed that there was a significant interaction between the onset age and duration of diabetes in patients diagnosed when aged ≤10 years regarding all anti‐islet autoantibodies (P < 0.05). However, for patients diagnosed in the middle tertile (aged 11–30 years), the interaction was significant only for ZnT8A, and for those with late‐onset diabetes (aged ≥31 years) only for IA‐2A. Conclusions The current study showed that the rate of disappearance of anti‐islet autoantibodies is faster in patients aged ≤10 years, and that even though both proteins are localized in the insulin granule membrane, humoral autoimmunity to IA‐2 and ZnT8 differs according to the age of onset.

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