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

Study of the diagnostic values of plasma Aβ,Aβ1-40,Aβ1-42 levels and their ratios to Alzheimer′s disease

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,-10.958,P<0.001)。Aβ1-42/Aβ曲线下面积为0.9775,最佳截断值为0.58。回归模型显示Aβ1-42/Aβ和Aβ1-40/Aβ是AD发生的重要危险因素。结论血浆Aβ1-42/Aβ和Aβ1-40/Aβ比值对AD有着良好的诊断效能,为人群中广泛筛查AD和实现AD的早期诊断提供了依据。

Objective To evaluate the diagnostic efficacy of the plasma amyloidβ-protein(Aβ),Aβ1-42,Aβ1-40 and their ratios and differences in expression levels in Alzheimer’s disease(AD)based on 89 AD patients diagnosed in West China Hospital of Sichuan University and 89 healthy control people.Methods According to clinical diagnosis,the study subjects were divided into an AD group and a healthy control group,with 89 cases each.Serum Aβ,Aβ1-40,Aβ1-42 both tests were performed using dual antibody sandwich enzyme-linked immunosorbent assay.Establish a receiver operating characteristic(ROC)curve to calculate the diagnostic efficacy of each indicator,and use stepwise regression analysis to analyze the risk of AD occurrence.Results The median levels of Aβ1-40(94.586 vs.73.419 pg/mL)and Aβ1-40/Aβ(0.825 vs.0.609)in AD patients were higher than those in healthy people(Z=-9.506,-9.704,P<0.001).The median levels Aβ1-42(56.536 vs.82.653 pg/mL),Aβ1-42/Aβ1-40(0.588 vs.1.141),Aβ1-42/Aβ(0.491 vs.0.680)were lower than those in healthy people(Z=-9.968,-10.507,-10.958,P<0.001).The area under curve of Aβ1-42/Aβwas the biggest(0.9775),and the best cut-off value of Aβ1-42/Aβwas 0.58.Regression model showed that Aβ1-42/Aβand Aβ1-40/Aβwere important risk factors for AD occurrence.Conclusion The plasma Aβ1-42/Aβand Aβ1-40/Aβratios have excellent diagnostic efficacy for AD,providing the basis for extensive screening of AD and achieving an early diagnosis of AD in the population.