Prevalence of Autoantibodies Against Pancreatic Beta Cells in Children with Type 1 Diabetes Mellitus

Zinc transporter autoantibody 8 (ZnT8A) was recently identified as a novel antibody antigen in type 1 diabetes mellitus, and its positivity is associated with early onset of the disease. So the present study was conducted to determine the prevalence of autoantibodies related to type 1 diabetes mellitus, especially ZnT8A as a newer antibody in children from 1 to 18 years of age referred to Amirkola Children's Hospital.

In this descriptive and analytical study, 80 children under 18 years of age with type 1 diabetes referred to Amirkola Children's Hospital, Babol, Iran during the years 2013 to 2021 were included in the study. Pediatric diabetes was diagnosed based on the criteria of the American Diabetes Association and with a visit to a pediatric endocrinologist. Antibodies related to type 1 diabetes including 65 glutamic decarboxylase (anti-GAD), protein tyrosine phosphatase (IA-2A), anti-islet cell autoantibodies (ICA), insulin autoantibodies (IAA), and zinc transporter 8 (ZnT8A) was measured from their blood samples at the time of disease diagnosis by ELISA method. Data were analyzed using t-test, chi-square, and Fisher's exact test. The significance level in this study was considered as p<0.05.

Samples were 80 children with an average age of 7.9±3.6 years (57% girls and 43% boys). The level of GADA in the studied samples was 65.2%, IA-2A 58.8%, ZnT8A 56.3%, ICA 47.5%, and IAA 6.3%.

93.8% of diabetic patients were autoantibody positive, which shows that by measuring the level of pancreatic antibodies, type 1 diabetes is confirmed in more than 90% of patients. Also, by measuring newer antibodies such as ZnT8A, the percentage of idiopathic type 1 diabetes cases also decreases.