血浆磷酸化-tau-苏氨酸181(p-tau181)是预测阿尔茨海默病(AD)和轻度认知障碍(MCI)的有前景的生物标志物。这是AD的症状性痴呆前阶段。迄今为止,目前对MCI和AD两个分期的诊断和分类存在局限性,在临床实践中仍然是一个两难的问题。在这项研究中,我们旨在区分和诊断MCI,AD,健康的参与者基于准确的,无标签,使用我们开发的基于电化学阻抗的生物传感器对人类临床血浆样品中的p-tau181水平进行超灵敏检测,这允许在0.92fgmL-1的极低浓度下检测p-tau181。收集20例AD患者的血浆样本,20名MCI患者和20名健康对照者。记录了由血浆样品中捕获p-tau181引起的开发的基于阻抗的生物传感器的电荷转移电阻的变化,以评估人类临床样品中血浆p-tau181水平的测定,以区分和诊断AD。MCI和健康对照者,分别。接收机工作特性(ROC)曲线,根据血浆p-tau181的估计水平判断我们的生物传感器平台的临床诊断能力的标准分析,得出的灵敏度为95%,特异性为85%,ROC曲线下面积(AUC)值为0.94的鉴别AD患者与健康对照的准确性;灵敏度为70%,特异性为70%,0.75的AUC区分MCI患者与健康对照。统计分析(单向方差分析(ANOVA))用于比较临床样品中估计的血浆p-tau181水平,表明健康对照的AD患者显着升高(***p≤0.001),AD合并MCI患者(***p≤0.001),和健康对照的MCI患者(*p≤0.05),分别。此外,我们将我们的传感器与全球认知功能量表进行了比较,发现它在诊断AD分期方面显着改善。这些结果证明了我们开发的基于电化学阻抗的生物传感器在临床疾病分期识别中的良好应用。此外,在这项研究中,首先确定了0.533pM的小解离常数(KD),以评估p-tau181生物标志物及其抗体之间的高结合亲和力,为p-tau181生物标志物和AD的未来研究提供参考参数。
Plasma phosphorylated-tau threonine 181 (p-tau181) is a promising biomarker for predicting Alzheimer\'s disease (AD) and mild cognitive impairment (MCI), which is the symptomatic pre-dementia stage of AD. To date, there are limitations in the current diagnosis and classification of the two stages of MCI and AD in clinical practice remain a dilemma. In this study, we aimed to discriminate and diagnose patients with MCI, AD, and healthy participants based on the accurate, label-free, and ultrasensitive detection of p-tau181 levels in human clinical plasma samples using our developed electrochemical impedance-based biosensor, which allows to detect p-tau181 at a very low concentration of 0.92 fg mL-1. Human plasma samples were collected from 20 patients with AD, 20 patients with MCI, and 20 individuals with healthy control. The change in charge-transfer resistance of the developed impedance-based biosensor caused by capturing p-tau181 in plasma samples was recorded to evaluate the determination of plasma p-tau181 levels in human clinical samples for discrimination and diagnosis of AD, MCI, and healthy control individuals, respectively. Receiver operating characteristic (ROC) curve, a standard analysis to judge the clinically diagnostic capability of our biosensor platform based on the estimated levels of plasma p-tau181, resulted a sensitivity of 95%, a specificity of 85%, the area under the ROC curve (AUC) value of 0.94 of the accuracy for discriminating AD patients from healthy controls; a sensitivity of 70%, a specificity of 70%, the AUC of 0.75 to discriminate MCI patients from healthy controls. Statistical analysis (one-way analysis of variance (ANOVA)) was used to compare the estimated plasma p-tau181 levels in clinical samples, indicated significantly higher for AD patients with healthy controls (***p ≤ 0.001), AD with MCI patients (***p ≤ 0.001), and MCI patients with healthy controls (*p ≤ 0.05), respectively. In addition, we compared our sensor to the global cognitive function scales and discovered that it performed noticeably improvement in diagnosing the stages of AD. These results demonstrated the good application of our developed electrochemical impedance-based biosensor in the identification of clinical disease stages. Moreover, in this study, a small dissociation constant (KD) of 0.533 pM was first determined to evaluate the high binding affinity between the p-tau181 biomarker and its antibody, providing a reference parameter for future studies of the p-tau181 biomarker and AD.