老年性痴呆患者血浆中β淀粉样蛋白Aβ_(1-42)和Aβ_(1-40)水平与对照组的对比研究

目的　研究老年性痴呆 (Alzheimer’sdisease ,AD)患者血浆中 β淀粉样蛋白 (amyloid betapeptide ,Aβ)Aβ1 4 2 、Aβ1 4 0 对临床诊断的意义。方法　分层选择了轻度AD组患者 2 3例 19≤简易智力状态检查表 (MMSE)≤ 2 6分 ,临床痴呆程度量表 (CDR) =1分 ],中度及中度以上AD组患者 35例 (MMSE <19分 ,CDR≥ 2分及年龄性别相匹配的健康对照 (HC)组 30例。所采集标本需EDTA抗凝管收集新鲜处理 ,低温离心取上清液、加苯磺酸 2h内置低温冰箱保存。应用酶联免疫吸附测定法对所有检测对象同批检测Aβ1 4 2 、β1 4 0 。结果　轻度AD患者Aβ1 4 2 血浆浓度较HC组显著升高 (P <0 .0 0 1) ,中度及中度以上AD患者Aβ1 4 2 血浆浓度随病情的加重而下降 ,与HC组比较差异无显著性意义 (P >0 .0 5 ) ,AD各组患者Aβ1 4 0 血浆浓度与HC组比较差异无显著性意义 (P >0 .0 5 )。结论　分层检测AD患者血浆中Aβ1 4 2 的浓度 ,有可能成为辅助诊断轻度AD的生物指标。

Study of plasma levels of Aβ1-42 and Aβ1-40 in patients with Alzheimer disease

Objective To study the plasma β-amyloid Aβ 1-42 and Aβ 1-40 for diagnosing AD.Methods Twenty-three patients with mild AD(19≤MMSE≤26,CDR=1),35 with moderate and severe AD(MMSE<19, CDR≥2) and 30 age-matched healthy controls (HC) were included in this study. Blood was collected from the subjects into tubes containing Na-EDTA, centrifugalized at 4℃ to separate plasma fraction,which was put into refrigerator for less than 2 h and measured for Aβ 1-42 and Aβ 1-40 using ELISA.Results Levels of Aβ 1-42 were higher in the mild AD group than in HC group, P<0.001, and were similar between patients in the moderate group and HC(P>0.05). AD patients had elevated plasma Aβ 1-40 , but no statistically significant difference as compared with HC(P>0.05). Conclusion The data indicate that plasma Aβ 1-42 is increased in mild AD, and with improvement of laboratory techniques, it may be a helpful biochemical tool for diagnosis of AD.