Quantitation of amyloid beta peptides Aβ1-38, Aβ1-40, and Aβ1-42 in human cerebrospinal fluid by ultra-performance liquid chromatography-tandem mass spectrometry
Quantitation of amyloid beta peptides Aβ1-38, Aβ1-40, and Aβ1-42 in human cerebrospinal fluid by ultra-performance liquid chromatography-tandem mass spectrometry
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DOI：
10.1016/j.ab.2011.08.010
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发表时间：
2011-12-15
影响因子：
2.9
通讯作者：
Blatnik, Matthew
中科院分区：
文献类型：
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作者：
Lame, Mary E.;Chambers, Erin E.;Blatnik, Matthew
阿尔茨海默病（AD）中的关键事件涉及淀粉样β（A β）肽从大脑的产生和清除之间的不平衡。目前的A β定量方法严重依赖于基于免疫的技术。然而，这些测定需要高度特异性的抗体和试剂，其开发耗时且昂贵。基于免疫的测定的特征还在于差的动态范围、交叉反应性、基质干扰和稀释线性问题。特别地，非商业免疫测定尤其经受高的测定内和测定间变异性，因为它们不经受更严格的制造控制。这些因素的组合使得免疫测定更加劳动密集型，并且通常难以验证以支持临床研究。在这里，我们描述了一种混合模式的固相萃取方法和超高效液相色谱串联质谱（SPE UPLC-MS/MS）测定同时定量A β（1-38），A β（1-40）和A β（1-42）从人脑脊液（CSF）。使用其相应的多反应监测（MRM）转换比较负离子与正离子物质，负离子的强度约为1.6倍，但在基质中缺乏选择性。阳离子MRM测定足以定量内源性All肽。在含有5%大鼠血浆的人工CSF中制备β标准品，并在三种合并CSF来源中制备质控样品。所有三种肽的提取效率均大于80%，并且所有物种在分析期间的变异系数均小于15%。三个CSF样本池中A β物质的平均基础水平分别为：A β（1-38）1.64、2.17和1.26 ng/ml; A β（1-40）3.24、3.63和2.55 ng/ml; A β（1-42）0.50、0.63和0.46 ng/ml。(C)2011 Elsevier Inc. All rights reserved.
Critical events in Alzheimer's disease (AD) involve an imbalance between the production and clearance of amyloid beta (A beta) peptides from the brain. Current methods for A beta quantitation rely heavily on immuno-based techniques. However, these assays require highly specific antibodies and reagents that are time-consuming and expensive to develop. Immuno-based assays are also characterized by poor dynamic ranges, cross-reactivity, matrix interferences, and dilution linearity problems. In particular, noncommercial immunoassays are especially subject to high intra- and interassay variability because they are not subject to more stringent manufacturing controls. Combinations of these factors make immunoassays more labor-intensive and often challenging to validate in support of clinical studies. Here we describe a mixed-mode solid-phase extraction method and an ultra-performance liquid chromatography tandem mass spectrometry (SPE UPLC-MS/MS) assay for the simultaneous quantitation of A beta(1-38), A beta(1-40), and A beta(1-42) from human cerebrospinal fluid (CSF). Negative ion versus positive ion species were compared using their corresponding multiple reaction monitoring (MRM) transitions, and negative ions were approximately 1.6-fold greater in intensity but lacked selectivity in matrix. The positive ion MRM assay was more than sufficient to quantify endogenous All peptides. A beta standards were prepared in artificial CSF containing 5% rat plasma, and quality control samples were prepared in three pooled CSF sources. Extraction efficiency was greater than 80% for all three peptides, and the coefficient of variation during analysis was less than 15% for all species. Mean basal levels of A beta species from three CSF pools were 1.64, 2.17, and 1.26 ng/ml for A beta(1-38); 3.24, 3.63, and 2.55 ng/ml for A beta(1-40); and 0.50, 0.63, and 0.46 ng/ml for A beta(1-42). (C) 2011 Elsevier Inc. All rights reserved.