Shoji Mikio
Department of Neurology, Division of Neuroscience, Biophysical Science, Okayama University Graduate School of Medicine and Dentistry, 2-5-1 Shikata-cho, Okayama, 700-8558 Japan.
Front Biosci. 2002 Apr 1;7:d997-1006. doi: 10.2741/A826.
Amyloid beta protein 40 (Abeta40) and 42 Abeta42, major components of senile plaque amyloids, are physiological peptides present in the brain, cerebrospinal fluid (CSF) and plasma. The levels of CSF Abeta40 and Abeta42(43) show a U-shaped natural course in normal aging. The increase of Abeta42(43) over 60 years of age is inhibited in Alzheimer's disease (AD). This specific alteration of CSF Abeta42(43) correlates with Abeta deposits in the AD brain providing a biological basis for a biomarker of AD. In the GTT2 study, assays of the CSF Abeta ratio ((Abeta40/ Abeta42(43)) showed a diagnostic sensitivity (59%) and specificity (88%) compared with non-AD type dementia and controls. The levels of the Abeta ratio increased from early to late stages of AD. Combination assays of CSF tau and Abeta ratio provided further efficient diagnostic sensitivity (81%) and specificity (87%). The reliability of the assay may prompt worldwide usage of these CSF biomarkers for Alzheimer's patients.
淀粉样β蛋白40（Aβ40）和42（Aβ42）是老年斑淀粉样蛋白的主要成分，是存在于大脑、脑脊液（CSF）和血浆中的生理肽。在正常衰老过程中，脑脊液Aβ40和Aβ42（43）水平呈U形自然变化过程。在阿尔茨海默病（AD）中，60岁以上人群Aβ42（43）的增加受到抑制。脑脊液Aβ42（43）的这种特定变化与AD大脑中的Aβ沉积相关，为AD生物标志物提供了生物学基础。在GTT2研究中，与非AD型痴呆和对照组相比，脑脊液Aβ比值（Aβ40/Aβ42（43））检测显示出诊断敏感性（59%）和特异性（88%）。Aβ比值水平从AD早期到晚期升高。脑脊液tau蛋白和Aβ比值联合检测提供了更高的诊断敏感性（81%）和特异性（87%）。该检测的可靠性可能促使这些脑脊液生物标志物在全球范围内用于阿尔茨海默病患者。
