老年性痴呆血浆中Aβ1-42、Aβ1-40及p-tau(^(181)P)蛋白的临床诊断意义

Study of Plasma Levels of Aβ1-42,Aβ1-40 and p-tau(^(181)P) in Alzheimer Disease

目的探讨血浆中β淀粉样蛋白(Aβ)142、Aβ140及过度磷酸化微管相关蛋白p tau(181P)对老年性痴呆(AD)的诊断意义。方法采用分层法选择早期AD患者23例(19≤MMSE≤26,CDR=1),中后期AD患者35例(MMSE<19,CDR≥2)及年龄、性别相匹配的健康对照组(HC)30例。所采集血标本置EDTA抗凝管中,低温离心取上清,加酸置低温冰箱保存。应用ELISA方法检测血浆Aβ142、Aβ140及p tau(181P)蛋白水平。结果早期AD患者血浆Aβ142浓度较HC组显著升高,随着病情加重AD患者血浆Aβ142浓度明显下降,至中后期其水平与HC组差异无显著性。而AD各组患者血浆Aβ140浓度与HC组比较差异无显著性。AD患者血浆中可检测到p tau(181P)蛋白且特异性较高,中后期AD患者血浆p tau(181P)蛋白浓度较HC组显著升高。结论根据病程将AD患者进行分层并对血标本进行特殊处理,检测血浆中Aβ142、Aβ140及p tau(181P)蛋白浓度可能成为临床辅助诊断AD的生物指标。

Objective To study the early diagnostic significance of improved method for determining plasma level of Aβ1-42, Aβ1-40 and p-tau (^(181)P) in Alzheimer disease. Methods Subjects with 23mild AD (19≤MMSE≤26) and 35 moderate and severe AD(MMSE<19, CDR≥2) and age-matched healthy control (HC, n=30) were included in this study. Improved sample collection and ELISA method were adopted. Results The sensitivity of improved eetermination method was significantly increased. The levels of Aβ1-42 in mild AD group was significantly statistically (P<0.001) higher than that in HC, and level of Aβ1-42 was similar between patients in the moderate-group and HC. The plasma Aβ1-40 in total AD group was slightly but not statistically significntly higher than that in HC group. Level of p-tau(^(181)P) was statistically significantly higher (P<0.001) in the severe AD group than that in HC.Conclusions The improved method for determining plasma Aβ1-42, Aβ1-40 and p-tau(^(181)P) might be a useful biochemical tool for the diagnosis of AD.