Laboratory of Analytical Chemistry and Biopolymer Structure Analysis, Department of Chemistry, University of Konstanz, Konstanz, Germany.
PLoS One. 2012;7(9):e44516. doi: 10.1371/journal.pone.0044516. Epub 2012 Sep 4.
Physiological β-amyloid autoantibodies (Aβ-autoantibodies) are currently investigated as potential diagnostic and therapeutic tools for Alzheimer's disease (AD). In previous studies, their determination in serum and cerebrospinal fluid (CSF) using indirect ELISA has provided controversial results, which may be due to the presence of preformed Aβ antigen-antibody immune complexes. Based on the epitope specificity of the Aβ-autoantibodies, recently elucidated in our laboratory, we developed (a) a sandwich ELISA for the determination of circulating Aβ-IgG immune complexes and (b) an indirect ELISA for the determination of free Aβ-autoantibodies. This methodology was applied to the analysis of serum samples from healthy individuals within the age range of 18 to 89 years. Neuropsychological examination of the participants in this study indicated non-pathological, age-related cognitive decline, revealed especially by tests of visual memory and executive function, as well as speed-related tasks. The ELISA serum determinations showed significantly higher levels of Aβ-IgG immune complexes compared to free Aβ-autoantibodies, while no correlation with age or cognitive performance of the participants was found.
生理β-淀粉样蛋白自身抗体（Aβ-autoantibodies）目前被作为阿尔茨海默病（AD）的潜在诊断和治疗工具进行研究。在之前的研究中，使用间接 ELISA 在血清和脑脊液（CSF）中测定其结果存在争议，这可能是由于存在预先形成的 Aβ 抗原-抗体免疫复合物。基于我们实验室最近阐明的 Aβ-autoantibodies 的表位特异性，我们开发了（a）用于测定循环 Aβ-IgG 免疫复合物的夹心 ELISA 和（b）用于测定游离 Aβ-autoantibodies 的间接 ELISA。该方法应用于分析年龄在 18 至 89 岁之间的健康个体的血清样本。该研究参与者的神经心理学检查表明存在非病理性、与年龄相关的认知能力下降，尤其是在视觉记忆和执行功能以及与速度相关的任务方面。ELISA 血清测定显示 Aβ-IgG 免疫复合物的水平明显高于游离 Aβ-autoantibodies，而与参与者的年龄或认知表现没有相关性。
