Triple chimeric islet autoantigen IA2-ZnT8WR to facilitate islet autoantibody determination

J Immunol Methods. 2010 Feb 28;353(1-2):20-3. doi: 10.1016/j.jim.2009.12.004. Epub 2009 Dec 24.


Type 1A diabetes is strongly associated with the presence of islet autoantibodies. Large scale population screening of islet autoantibodies is essential for many different national and international studies related to defining subtypes of diabetes, the natural history of the disease, and for trials of prevention. Testing for relevant autoantibodies has become more difficult as the number of important autoantibodies/epitopes increases. In the present study, we created a chimeric protein, IA2-ZnT8WR, with two major islet autoantigens, IA-2 and the recent Zinc transporter 8 (ZnT8). The chimeric molecule included both common polymorphisms of the ZnT8 molecule, arginine or tryptophan at position 325. Serum samples from 284 patients with newly diagnosed diabetes, 10 prediabetics, and 110 age-matched normal controls were analyzed for islet autoantibodies reacting with the IA2-ZnT8WR molecule. Autoantibodies to the chimeric molecule were compared to reactivity with individual assays detecting autoantibodies reacting with the separate molecules (IA-2, ZnT8-R and ZnT8-W). With this chimeric protein antigen, IA2-ZnT8WR, one radioassay is able to detect autoantibodies to IA-2 and to both major forms of ZnT8 (100% sensitivity, 100% unchanged specificity, relative to individual molecules). The chimeric assay provides an efficient and economical technique to screen for islet autoantibodies reacting with IA-2 and ZnT8.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adolescent
  • Autoantibodies / blood*
  • Autoantigens / genetics
  • Autoantigens / immunology*
  • Case-Control Studies
  • Cation Transport Proteins / genetics
  • Cation Transport Proteins / immunology*
  • Child
  • Child, Preschool
  • Diabetes Mellitus, Type 1 / immunology*
  • Humans
  • Infant
  • Islets of Langerhans / immunology*
  • Polymorphism, Genetic
  • Prediabetic State / immunology*
  • Predictive Value of Tests
  • Radioimmunoassay
  • Receptor-Like Protein Tyrosine Phosphatases, Class 8 / immunology*
  • Recombinant Fusion Proteins / immunology
  • Sensitivity and Specificity
  • Young Adult
  • Zinc Transporter 8


  • Autoantibodies
  • Autoantigens
  • Cation Transport Proteins
  • Recombinant Fusion Proteins
  • SLC30A8 protein, human
  • Zinc Transporter 8
  • PTPRN protein, human
  • Receptor-Like Protein Tyrosine Phosphatases, Class 8