Barbara Davis Center for Childhood Diabetes, University of Colorado Denver, Aurora, CO, United States.
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.
1 型糖尿病与胰岛自身抗体的存在密切相关。对胰岛自身抗体进行大规模人群筛查对于许多与糖尿病亚型定义、疾病自然史以及预防试验相关的不同国家和国际研究至关重要。随着重要的自身抗体/表位数量的增加，检测相关自身抗体变得更加困难。在本研究中，我们创建了一种嵌合蛋白 IA2-ZnT8WR，它包含两个主要的胰岛自身抗原，IA-2 和最近的锌转运体 8（ZnT8）。该嵌合分子包含 ZnT8 分子的两个常见多态性，即第 325 位的精氨酸或色氨酸。分析了 284 名新诊断为糖尿病的患者、10 名糖尿病前期患者和 110 名年龄匹配的正常对照者的血清样本中与 IA2-ZnT8WR 分子反应的胰岛自身抗体。将针对嵌合分子的自身抗体与单独检测与单独分子（IA-2、ZnT8-R 和 ZnT8-W）反应的自身抗体的反应性进行比较。使用这种嵌合蛋白抗原 IA2-ZnT8WR，一种放射免疫分析法能够检测到与 IA-2 和两种主要形式的 ZnT8 反应的自身抗体（100%的敏感性，100%不变的特异性，与单独的分子相比）。该嵌合检测法提供了一种高效且经济的技术来筛选与 IA-2 和 ZnT8 反应的胰岛自身抗体。
