Autoantibodies in Type 1 Diabetes

DESCRIPTION

• 4 autoantibodies are markers of beta cell autoimmunity in type 1 diabetes: islet cell antibodies (ICA, against cytoplasmic proteins in the beta cell), antibodies to glutamic acid decarboxylase (GAD-65), insulin autoantibodies (IAA), and IA-2A, to protein tyrosine phosphatase[2].
• Autoantibodies against GAD 65 are found in 80% of patients with type 1 diabetes at clinical presentation[3].
• Presence of ICA and IA-2A at diagnosis for type 1 diabetes range from 69-90% and 54-75%, respectively[11].
• IAA prevalence correlates inversely with age at onset of diabetes; it is usually the first marker in young children at risk for diabetes [17] and found in approximately 70% of young children at time of diagnosis[1].
• In the Diabetes Autoantibody Standardization Program 2000 workshop, the ELISA for the insulin autoantibody (IAA) assay ranged in sensitivity of 4-42%; the standardization of the insulin antibody assay continues to be more challenging than for GAD or IA-2A antibodies[16].