阿尔茨海默病与血管性痴呆血浆和脑脊液β淀粉样蛋白肽比较研究

目的探讨β淀粉样蛋白肽Aβ1-40和Aβ1-42水平在阿尔茨海默病（AD）与血管性痴呆（VD）鉴别诊断中的作用及与认知功能损害的关系。比较AD患者血浆和脑脊液中Aβ1-40与Aβ1-42含量的异同。方法收集AD、VD患者各20例,分别测定血浆Aβ1-40、Aβ1-42含量并进行比较。其中10例AD患者同时检测血浆及脑脊液Aβ1-40、Aβ1-42含量并进行比较。采用简明精神状态量表（MMSE）评定认知功能损害。结果 （1）AD组血浆Aβ1-40含量（69.56±14.15）pg/ml,VD组血浆Aβ1-40含量（78.34±17.24）pg/ml,二者差异无统计学意义（P〉0.05）;AD组血浆Aβ1-42含量（17.61±12.70）pg/ml,VD组血浆Aβ1-42含量（20.23±9.57）pg/ml,二者比较,差异无统计学意义（P〉0.05）。AD组血浆Aβ1-40是Aβ1-42的（5.21±2.64）倍,VD组血浆Aβ1-40是Aβ1-42的（4.56±1.81）倍,两组Aβ1-40/Aβ1-42比值差异无统计学意义（P〉0.05）。（2）AD组脑脊液Aβ1-40、Aβ1-42含量显著高于血浆,两者比较差异有统计学意义（P〈0.01）。（3）相关性分析显示,AD、VD组血浆Aβ1-40、Aβ1-42含量与认知功能损害、性别、文化程度、病程均无显著相关性（P〉0.05）,AD组Aβ1-40含量与年龄呈显著正相关（r=0.724,P=0.000）,VD组Aβ1-42含量与年龄呈显著负相关（r=-0.606,P=0.005）,与Aβ1-40之间有显著正相关性（r=0.567,P=0.009）。结论外周血中Aβ1-40和Aβ1-42水平不能作为临床诊断AD及与VD鉴别的敏感性和特异性指标,血浆中Aβ1-40的检测灵敏度比Aβ1-42更高。血浆Aβ1-40和Aβ1-42水平与AD、VD发病年龄呈显著相关。     

血浆和脑脊液Aβ42、tau水平对阿尔茨海默病患者的早期诊断价值

目的研究血浆和脑脊液生物标志物β淀粉样蛋白(Aβ)42和tau蛋白对阿尔茨海默病早期诊断的价值。方法选取该院接受治疗的阿尔茨海默病患者(AD组)、轻度认知障碍患者(MCI组)和无痴呆健康老人(NC组)共计86例,比较各组血浆和脑脊液Aβ42和tau蛋白水平,并分析其相关性。结果 AD组血浆tau蛋白、脑脊液tau蛋白水平高于NC组,血浆Aβ42、脑脊液Aβ42水平低于NC组,差异均有统计学意义(P0.05)。MCI组血浆tau蛋白高于NC组,脑脊液Aβ42水平低于NC组,差异均有统计学意义(P0.05)。AD组血浆tau蛋白、脑脊液tau蛋白水平高于MCI组,脑脊液Aβ42蛋白水平低于MCI组,差异均有统计学意义(P0.05)。脑脊液tau蛋白水平与Aβ42蛋白水平呈负相关(r=-0.405,P0.05)。结论阿尔茨海默病的发生与发展可能与血浆、脑脊液的tau蛋白、Aβ42蛋白水平异常有关,通过检测上述生物标志物,可有效预测阿尔茨海默病的发生与进展情况。     

血浆Aβ、Aβ1-40、Aβ1-42水平及其比值对阿尔兹海默病诊断价值的研究

目的 基于于四川大学华西医院诊断为阿尔兹海默病(AD)的89例患者及89例健康对照人群,研究血β-淀粉样蛋白(Aβ)、Aβ1-40、Aβ1-42及其比值在两组人群中表达水平的差异及各指标对AD的诊断效能。方法 根据临床诊断将研究对象分为AD组和健康对照组,各89例。血清Aβ、Aβ1-40、Aβ1-42检测均采用双抗体夹心酶联免疫吸附试验。建立受试者工作特征曲线计算各指标诊断效能,采用逐步回归分析AD发生的危险风险。结果 AD组中位Aβ1-40(94.586 pg/mL)、Aβ1-40/Aβ(0.825)高于健康对照组中位Aβ1-40(73.419 pg/mL)、Aβ1-40/Aβ(0.609),差异有统计学意义(Z=-9.506,-9.704,P<0.001)。AD组中位Aβ1-42(56.536 pg/mL)、Aβ1-42/Aβ1-40(0.588)、Aβ1-42/Aβ(0.491)低于健康对照组中位Aβ1-42(82.653 pg/mL)、Aβ1-42/Aβ1-40(1.141)、Aβ1-42/Aβ(0.680),差异有统计学意义(Z=-9.968,-10.507,-10.9...     

轻度认知功能障碍患者Aβ1-42、Tau蛋白、Lp-PLA2水平变化及其与脑电图的关系

目的 探讨轻度认知功能障碍（MCI）患者血清β-淀粉样多肽（1-42）(Aβ1-42)、Tau蛋白、脂蛋白相关磷脂酶A2(Lp-PLA2)水平的变化及其与脑电图参数的相关性。方法 选取老年MCI患者80例（MCI组）、阿尔茨海默病（AD）患者80例（AD组）、健康体检者80名（正常对照组）,收集所有对象的一般资料,检测其血清Aβ1-42、Tau蛋白、Lp-PLA2水平,并行脑电图检查。比较各组各项检测、检查结果的差异。采用Pearson相关分析评估各项指标之间的相关性。结果 AD组、MCI组、正常对照组血清Aβ1-42水平依次升高（P<0.05）,血清Tau蛋白和Lp-PLA2水平依次降低（P<0.05）。MCI组、AD组α1波、δ波、θ波脑电功率均高于正常对照组（P<0.05）;AD组δ波、θ波脑电功率均高于MCI组（P<0.05）;3个组α2波、β1波、β2波脑电功率差异均无统计学意义（P>0.05）。Pearson相关分析结果显示,MCI患者δ波、θ波脑电功率与Aβ1-42水平呈负相关（r值分别为-0.447、-0.482,P值分别为0.001、&l...     

阿尔茨海默病患者空腹血糖、真胰岛素、C肽及β淀粉样蛋白的水平

目的探讨阿尔茨海默病（AD）患者胰岛素及β淀粉样蛋白（Aβ）的异常代谢。方法随机选取70名正常人（对照组）、55例AD患者,检验其空腹血糖、真胰岛素、C肽、Aβ40、Aβ42水平。将AD患者按痴呆轻、中重度分组后与对照组进行比较。结果对照组比较,AD患者各组空腹血糖无显著性差异（P〉0.05）,中重度组真胰岛素和C肽升高（P〈0.05）,中重度组Aβ40升高（P〈0.05）,轻度组Aβ42明显升高（P〈0.01）。结论AD患者体内存在胰岛素及β淀粉样蛋白代谢异常,其特征与痴呆的严重程度有关。     

人血浆β淀粉样蛋白42ELISA的建立及其临床初步应用

目的建立人血浆中β淀粉样蛋白42（Aβ42）酶联免疫吸附试验（ELISA）,并初步观察其对诊断阿尔茨海默病（AD）的应用价值。方法用鼠抗Aβ42片段（1～28氨基酸残基）单克隆抗体包被微孔板,用生物素标记的兔抗Aβ42片段（40～42氨基酸残基）为标记抗体,应用生物素-亲和素系统（ABS）进行放大,采用棋盘滴定方法确定最佳实验条件,用Aβ42标准品建立ELISA标准曲线,分别检测不同痴呆程度AD患者及健康人血浆中Aβ水平。结果本研究建立的方法测定范围为20—500pg／mL,最低检出量20pg／mL,批内和批间变异系数（c叻分别为3．8％和7．9％。轻度AD患者血浆中AB42水平为（146．4±9．7）pg／mL,明显高于健康对照组[（95．I±7．2）pg／mL],中晚期AD患者血浆Aβ42浓度明显下降[（99．4±17．6）pg／mL],其水平降至与健康对照组差异无统计学意义。结论建立的人血浆Aβ42ELISA可作为AD早期诊断的有效方法,可在临床推广应用。     

阿尔茨海默病患者脑脊液蛋白指标敏感性及特异性

目的探讨联合分析脑脊液中Tau蛋白、β淀粉样蛋白(Aβ)1-40、Aβ1-42(43)含量作为生化指标对诊断阿尔茨海默病(Alzheimer's disease,AD)的意义.方法采用夹心酶联免疫(sELISA)法测定上述生化指标,分析了21例AD,28例非AD痴呆,35例其他神经系统疾病患者,50例正常对照者脑脊液中Tau、Aβ1-40、Aβ1-42(43)水平的差异.结果Tau水平随年龄而增加,AD组Tau水平为(491.5±35.7)ng/L且与临床进程存在相关性,Aβ1-42(43)水平为(109.9±73.2)pmol/L,Aβ1-40/Aβ1-42(43)为(16.03±4.07).AD组Tau水平、Aβ1-40/Aβ1-42(43)比率显著高于其他组(P＜0.001),Aβ1-42(43)水平低于其他组.结论同时测定脑脊液中的Tau、Aβ1-40、Aβ1-42(43)的含量对于AD的诊断有良好的特异性,对于AD与其他类型的痴呆和其他神经系统疾病的鉴别诊断具有意义.     

Alzheimer病早期生化诊断指标的进展

Alzheimer病（AD）的早期诊断是其治疗和预后的限制性因素。目前从AD患者脑脊液中发现一些具有诊断意义的生化指标有tau蛋白,β－淀粉样蛋白（Aβ）,载脂蛋白E（ApoE),Aβ的前体蛋白（APP）,早老素（PS－1,PS－2）和天冬氨酸转氨酶（AST）等。其中以脑脊液中的tau蛋白,尤其是过度磷酸化tau蛋白（p-tan）有可能成为AD的早期诊断的生化指标。     

复合型AD模型鼠中硫氧还蛋白及凋亡蛋白的研究

目的：初步探讨β淀粉样蛋白1～42（Aβ1～42）及D-半乳糖（D-gal）联合构建的复合型阿尔茨海默病（AD）模型,以及模型中硫氧还蛋白与凋亡相关蛋白的研究。方法采用44只2月龄雄性SD大鼠,共分4组,腹腔注射及侧脑室注射生理盐水的假手术组,腹腔注射D-gal及侧脑室注射Aβ1～42分别建立的D-gal组和Aβ1～42组,腹腔注射D-gal联合侧脑室注射Aβ1～42建立的复合AD模型组。免疫组织化学检测脑组织中Trx,细胞色素c（Cyto-c）及Caspase-9表达。结果与对照组相比,Aβ1～42组、D-gal组和复合模型组皮质、海马中Trx的表达下降,Cyto-c和Caspase-9的表达上升。与Aβ1～42组、D-gal组相比,复合模型组皮质、海马中Trx的表达下降;Cyto-c和Caspase-9的表达上升。结论在复合AD模型中神经细胞凋亡,Trx表达下降,而Cyto-c和Caspase-9表达上升。Trx参与神经细胞的凋亡过程。     

阿尔茨海默病患者血清Aβ1-42和血小板聚集功能联合测定的临床意义

目的：探讨血清β-淀粉样蛋白（Aβ-42）、血小板聚集功能（PAgT）在阿尔茨海默病（AD）诊疗中的临床意义。方法：采用双抗体夹心酶联免疫吸附法（ELISA）检测26例AD患者和28例健康对照者血清中Aβ1-42蛋白水平,采用比浊法检测其PAsT水平。结果：AD患者Aβ1-42水平为（38．5±12．4）Pg／ml明显低于于对照组（56．6±14．2）Pg／ml（P〈0．01）,PA盯水平为为（64．2±13．5）％则明显高于对照组（53．6±7．6）％（P〈0．01）。Pearson相关分析显示简易智能状态检查量表（MMSE）评分与PAgT呈明显负相关（r=-0．439,P〈0．05）。结论：动态检测AD患者血清AB1-42、PAgT水平的变化,在AD临床诊疗中有着重要意义。     

脑脊液CK、Aβ42、P-tau在阿尔茨海默病中的诊断价值

目的 探究脑脊液CK、Aβ42、P-tau在阿尔茨海默病中的诊断价值.方法 选取2018年5月至2020年5月本院收治的40例阿尔茨海默病患者(AD)为研究对象,另选取40例轻度认知障碍期患者(MCI),40例血管性痴呆患者(VD),40例健康体检人员为对照组.采用ELISA法测定四组脑脊液CK、Aβ42、P-tau水...     

Method comparison study of the Elecsys® β-Amyloid (1–42) CSF assay versus comparator assays and LC-MS/MS

BackgroundAlzheimer's disease (AD) biomarkers, such as cerebrospinal fluid (CSF) amyloid-β (1–42; Aβ42), can provide high diagnostic accuracy. Several immunoassays are available for Aβ42 quantitation, but standardisation across assays remains an issue. We compared the Elecsys® β-Amyloid (1–42) CSF assay with three assays and two liquid chromatography tandem mass spectrometry (LC-MS/MS) methods.MethodsThree method comparison studies evaluated the correlation between the Elecsys® β-Amyloid (1–42) CSF assay versus: INNOTEST® β-AMYLOID(1–42) (860 samples) and the Roche Diagnostics-developed LC-MS/MS method (250 samples); INNO-BIA AlzBio3 and the University of Pennsylvania (UPenn)-developed LC-MS/MS method (250 samples); and ADx-EUROIMMUN Beta-Amyloid (1–42) enzyme-linked immunosorbent assay (ELISA) (49 samples).ResultsHigh correlation was demonstrated between Elecsys® β-Amyloid (1–42) CSF and comparator assays: INNOTEST® β-AMYLOID(1–42) (Spearman's ρ, 0.954); INNO-BIA AlzBio3 (Spearman's ρ, 0.864); ADx-EUROIMMUN Beta-Amyloid (1–42) ELISA (Pearson's r, 0.925). Elecsys® assay and LC-MS/MS measurements were highly correlated: Pearson's r, 0.949 (Roche Diagnostics-developed method) and 0.943 (UPenn-developed method).ConclusionFindings from this multicentre evaluation further support use of the Elecsys® β-Amyloid (1–42) CSF assay to aid AD diagnosis. CSF-based certified reference materials should improve agreement across assays and mass spectrometry-based methods, which is essential to establish a global uniform CSF Aβ42 cut-off to detect amyloid pathology.     

胸腹主动脉夹层手术脊髓损伤标记物临床研究

目的探讨脑脊液生化指标监测对胸腹主动脉夹层术后脊髓缺血损害判断的临床意义。方法将50例胸腹主动脉夹层手术患者根据术后是否发生脊髓缺血损害并发症分成损伤组（SCI组,n=5）和无损伤组（NSCI组,n=45）。术前、术后分7个时点对脑脊液取样,对胶质纤维酸蛋白（GFAP）、S100β蛋白以及神经丝蛋白亚单位（NFL）等3个生化指标进行测定。比较分析上述3个生化指标在2组之间的变化。将无脊髓损伤患者据术式分为血管置换手术组（AR组,n=9）和腔内隔绝术组（EVGE组,n=36）,同样比较分析上述3个生化指标在2组之间的差异。结果 SCI组术后6 h各项生化指标开始升高,48-72 h各项指标明显高于NSCI组（P〈0.01）。术后6 h以后GFAP、S100β蛋白测定数值在2组之间数值无重叠。腔内隔绝术后各项指标无明显升高,血管置换术后6 h起GFAP、S100β开始升高,术后24 h达到峰值,较术前相比差异有统计学意义（P〈0.05）,同时高于腔内隔绝术后对应时点。血管置换术后（第24h4、8 h）时点NFL高于腔内隔绝术后对应时点（P〈0.05）。结论脑脊液生化指标持续监测可以预判迟发性脊髓损害。GFAP、S100β蛋白比NFL诊断脊髓损伤有更高的预测价值。     

Diagnostic accuracy of ELISA and xMAP technology for analysis of amyloid beta(42) and tau proteins

BACKGROUND: Cerebrospinal fluid (CSF) concentrations of amyloid beta(42) (Abeta(42)) peptides and tau proteins may serve as biomarkers for Alzheimer disease (AD). Recently, the xMAP technology has been introduced as an alternative to ELISA for measurement of these markers. METHODS: We used xMAP assays and ELISA to analyze CSF concentrations of Abeta(42), total tau (t-tau), and tau phosphorylated at threonine 181 (p-tau(181)) in samples from 69 patients with Alzheimer disease, 26 patients with vascular dementia, and 55 controls without neurological disorders. RESULTS: High CV values (>28%) for the ratio of xMAP:ELISA were observed for each biomarker, indicating that a constant correction factor cannot be applied to recalculate xMAP results into ELISA results. When a combination of CSF markers was used, the sensitivity, specificity, and area under the ROC curves for xMAP assays and ELISAs were not significantly different in differentiating AD patients from vascular dementia patients and controls. CONCLUSIONS: A constant conversion factor cannot be used successfully to recalculate results obtained with xMAP assays to those from the ELISAs. With the use of analysis of a combination of Abeta(42), t-tau, and p-tau in CSF, however, differentiation of clinical groups is equivalent when either xMAP technology or conventional ELISA is used.     

Advances in the detection of Alzheimer's disease-use of cerebrospinal fluid biomarkers

The diagnosis of Alzheimer's disease (AD) is still made by excluding other disorders with a similar clinical picture. In addition, an analysis of symptoms and signs, blood analyses and brain imaging are the major ingredients of the clinical diagnostic work-up. However, the sensitivity of a clinical diagnosis using these instruments is unsatisfactory and disease markers with high sensitivity and specificity for AD would be a welcome supplement. Ideally, such markers should reflect the pathophysiological mechanisms of AD, that is, according to the currently predominant hypothesis mismetabolism of beta-amyloid and neurofibrillary degeneration. Among several, we have focused on three candidates that have been suggested to fulfil the requirements for biomarkers of AD: beta-amyloid42 (Abeta42), total tau (T-tau) and tau phosphorylated at various epitopes (P-tau). The cerebrospinal fluid (CSF) levels of these proteins reflect the metabolism of these proteins in the central nervous system. Only published articles using established ELISA methods for the quantification of these markers in CSF and preferably also presenting sensitivity and specificity figures have been included in this review. The number of patients included in the different studies varies; some having included only a few patients. Furthermore, diagnostic criteria vary and clinicopathological studies are scarce. However, there are some large studies, including even minor studies, and most have found reduced CSF levels of Abeta42 and increased CSF levels of T-tau in AD. The sensitivity and specificity of these measures are high for separation of AD patients from controls, but their specificity against other dementias is moderate. It increases if P-tau is added. An increasing number of studies suggest that supplementary use of these CSF markers, preferably in combination, adds to the accuracy of an AD diagnosis.     

Combining MRI and CSF measures for classification of Alzheimer's disease and prediction of mild cognitive impairment conversion

The suggested revision of the NINCDS-ADRDA criterion for the diagnosis of Alzheimer's disease (AD) includes at least one abnormal biomarker among magnetic resonance imaging (MRI), positron emission tomography (PET) and cerebrospinal fluid (CSF). We aimed to investigate if the combination of baseline MRI and CSF could enhance the classification of AD compared to using either alone and predict mild cognitive impairment (MCI) conversion at multiple future time points. 369 subjects from the Alzheimer's disease Neuroimaging Initiative (ADNI) were included in the study (AD=96, MCI=162 and CTL=111). Freesurfer was used to generate regional subcortical volumes and cortical thickness measures. A total of 60 variables were used for orthogonal partial least squares to latent structures (OPLS) multivariate analysis (57 MRI measures and 3 CSF measures: Aβ(42), t-tau and p-tau). Combining MRI and CSF gave the best results for distinguishing AD vs. CTL. We found an accuracy of 91.8% for the combined model at baseline compared to 81.6% for CSF measures and 87.0% for MRI measures alone. The combined model also gave the best accuracy when distinguishing between MCI vs. CTL (77.6%) at baseline. MCI subjects who converted to AD by 12 and 18month follow-up were accurately predicted at baseline using an AD vs. CTL model (82.9% and 86.4% respectively), with lower prediction accuracies for those MCI subjects converting by 24 and 36month follow up (75.4% and 68.0% respectively). The overall prediction accuracies for converters and non-converters ranged from 58.6% to 66.4% at different time points. Combining MRI and CSF measures in a multivariate model at baseline gave better accuracy for discriminating between AD and CTL, between MCI and CTL and for predicting future conversion from MCI to AD, than using either MRI or CSF separately.     

Total tau protein, phosphorylated tau (181p) protein, beta-amyloid(1-42), and beta-amyloid(1-40) in cerebrospinal fluid of patients with dementia with Lewy bodies.

The intra vitam diagnosis of different dementias is still based on clinical grounds. So far, no technical investigations have been available to support these diagnoses. For tau protein and beta-amyloid(1-42) in cerebrospinal fluid (CSF), promising results for the diagnosis of Alzheimer's disease (AD) have been reported; however, their differential diagnostic spectrum is limited, as was recently shown for dementia with Lewy bodies (DLB) and for AD. Therefore, further marker proteins have to be established to ameliorate, support, and differentiate these clinical diagnoses. We evaluated beta-amyloid(1-40) and phosphorylated tau protein (181p), in addition to total tau protein and beta-amyloid(1-42), in 20 patients with DLB, 34 AD patients, and 20 non-demented neurological controls (NDCs). All markers could differentiate between the dementia groups (AD, DLB) and the controls. AD and DLB could be differentiated only by levels of total tau protein and by the ratio total tau protein/phosphorylated tau protein. However, values still overlapped markedly. In some cases, tau protein levels in CSF may contribute to the clinical distinction between DLB and AD, but the value of the markers is still limited, especially because of mixed pathology. We conclude that more specific markers have to be established to differentiate between these diseases.     

Human kallikrein 6 as a biomarker of alzheimer's disease

Background: Alzheimer’s disease (AD) is a major cause of dementia in the elderly. It is generally difficult to diagnose accurately early AD. A few biomarkers, including τ protein and amyloid β-42, are now used as aids for diagnosis and monitoring of AD. Our aim was to examine the possible use of cerebrospinal fluid, blood and tissue, and human kallikrein 6 (hK6) concentration as a marker of AD.

Methods: We have used a highly sensitive and specific immunofluorometric procedure for measuring hK6. We measured hK6 in tissue extracts from AD brain or normal individuals, in cerebrospinal fluids of AD patients or normals and in whole blood of AD patients and normals and compared the findings. We have used ten pairs of AD/normal controls in all cases.

Results: We found that hK6 concentration is tissue extracts from AD brain were approximately twofold lower than extracts from normal controls. Further, we found that cerebrospinal fluid hK6 concentration is approximately a threefold increase, in comparison to cerebrospinal fluid controls (p = 0.001). We have also found that the whole blood hK6 concentration in AD patients is about ten times higher than hK6 concentration in normal controls (p = 0.002). We have immunohistochemically localized the expression of hK6 in epithelial cells of the chorioid plexus.

Conclusions: This is the first report describing significant elevations of cerebrospinal fluid and plasma and whole blood hK6 concentration in AD patients, in comparison to controls. These data suggest that hK6 may constitute a new biomarker for diagnosis and monitoring of AD.