Identification of insulin autoantibodies of IgA isotype that preferentially target non-human insulin

Clin Immunol. 2007 Jul;124(1):77-82. doi: 10.1016/j.clim.2007.03.545. Epub 2007 May 23.


Insulin autoantibodies (IAA) precede clinical type 1 diabetes in children. Immunization events leading to IAA are unknown. The aim of this study was to determine whether some IAA result from mucosal immunization. IgA-IAA and binding of IAA to non-human insulin were examined in selected high and low affinity IAA-positive samples and in first IAA-positive samples from children aged <2 years. High affinity IAA (>10(9)L/mol) bound strongly to human insulin and poorly to chicken insulin. In contrast, 12/13 lower affinity IAA were chicken insulin-reactive, binding equally to human and chicken insulin (n=4), or preferentially binding chicken insulin (n=8). IgA-IAA were found in association with chicken insulin-reactive IAA, and included cases where IgA-IAA predominated over IgG-IAA. Among 20 IAA-positive children aged <2 years, one had early IgA-chicken insulin-reactive IAA that were replaced by high affinity IgG-IAA. The findings suggest that some IAA can result from immunization against molecules other than human insulin at mucosal sites.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Animals
  • Antibody Specificity
  • Autoantibodies / blood*
  • Binding, Competitive
  • Chickens
  • Child
  • Child, Preschool
  • Cohort Studies
  • Cross Reactions / immunology
  • Diabetes Mellitus, Type 1 / epidemiology
  • Diabetes Mellitus, Type 1 / genetics
  • Diabetes Mellitus, Type 1 / immunology*
  • Humans
  • Immunoglobulin A / blood*
  • Immunoglobulin G / blood
  • Infant
  • Insulin / chemistry
  • Insulin / immunology*
  • Insulin Antibodies / analysis*
  • Insulin Antibodies / metabolism
  • Prospective Studies


  • Autoantibodies
  • Immunoglobulin A
  • Immunoglobulin G
  • Insulin
  • Insulin Antibodies