摘要
目的 建立β淀粉样肽42（β-amyloid peptide 42,Aβ42）酶联免疫吸附测定法（enzymelinked immunosorbent assay,ELISA）,并探讨其检测阿尔茨海默病（alzheimer disease,AD）患者血清Aβ42含量及其早期诊断、治疗的临床意义.方法 利用噬菌体抗体库技术制备抗Aβ42的单链抗体,用作包被抗体；并与用Aβ42免疫兔制备的抗Aβ42的多克隆抗体及辣根过氧化物酶标记的羊抗兔IgG建立检测外周血Aβ42的ELISA方法.然后,用其检测120例AD患者和120例血管性痴呆（vascular dementiao,VD）或脑梗死患者、120名健康人血清的Aβ42含量,同时通过重复性、稳定性、回收试验和与国外试剂比对分析进行方法学评价与诊断性能分析.结果 建立的Aβ42 ELISA法检测2份血清标本重复20次的批内变异系数（coefficient of varible,CV）分别为3.6％和3.5％,重复检测20 d的批间CV分别为6.8％和7.1％；回收率为97.2％～103.1％,线性范围为0.050～2μg/L;在37℃放置6d及4℃保存6个月的活性降低均＜12％.与比利时INNOTEST双抗体夹心ELISA β淀粉样肽检测试剂盒平行检测90份标本,自建方法检测Aβ42含量为（0.207±0.039）μg/L,INNOTEST试剂盒为（0.206 ±0.038） μg/L；两种方法有较好的一致性（回归方程为Y=1.011X-0.003,R2=0.979,P＜0.01）.ELISA检测AD组血清Aβ42为（0.247 ±0.032） μg/L,VD或脑梗死组为（0.173±0.028） μg/L,健康对照组为（0.172±0.032）μg/L;AD组分别高于VD或脑梗死组和健康对照组（q值分别为18.687、18.907,P均＜0.01）.用受试者操作特征（receiver operating characteristic,ROC）曲线确定Aβ42的临界值为0.212 μg/L,正常参考值范围为0～0.212 μg/L时,ELISA Aβ42诊断VD的敏感度为86.7％（104/120）,特异度为90.8％（218/240）.结论 建立的AD血清Aβ42 ELISA法的敏感度和特异度较高,重复性及稳定性较好,为AD患者的早期诊断和治疗监测提供了新的有效方法.
Objective To establish a enzyme-linked immunosorbent assay （ELISA） method for detecting the β-amyloid peptide 42 （ Aβ42 ） and explore its clinical meaning for diagnosis and treatment in the early stages of the alzheimer disease （ AD）.Methods Using the Aβ42 single chain variable fragment constructed by phage antibody library display system as coat antibody,associated with the Aβ42 polyclonal antibody acquired by Aβ42 immunized rabbit and HRP labeled goat anti rabbit IgG to establish ELISA method for detecting the Aβ42 in peripheral blood.The method was used it to test the Aβ42 in 120 vascular dementia VD） or cerebral vessel infarction patients and 120 AD patients and 120 controls.The methodology performance were evaluated.Results The inter and intra coefficient of variable （CV） of this self-established ELISA method was 3.6% and 3.5%,6.8% and 7.1% respectively.The recovery rate was 97.2% -103.1%.The linear range was 0.050 - 2 μg,/L.Its reactivity decreased 〈 12% when it was put in both 37 ℃ for 6 days and 4 ℃ for 6 months.Compared with the Belgium INNOTEST reagent by testing 90 samples simultaneously,the results of self-established method was （0.207 ± 0.039 ） μg/L,the results of INNOTEST was （0.206± 0.038 ） μg/L; the regression equation was Y =1.011X - 0.003,R2 =0.979,P 〈0.01.The Aβ42 in blood of AD group was （0.247 ± 0.032 ） μg/L,VD or cerebral vessel infarction group was （0.173 ±0.028） μg/L,control group was （0.172 ±0.032） μg/L.The Aβ42 in AD group was higher than that in the VD or cerebral vessel infarction group and control group （q =18.867,18.907respectively,P 〈 0.01 ）.The cut off value was 0.212 μg/L decided by the receiver operating characteristic （ROC） curve.The reference interval was 0 -0.212 μg/L.The sensitivity of this ELISA method was 86.7%（104/120） and specificity was 90.8% （218/240）.Conclusions The ELISA method for detecting Aβ42 in peripheral blood established by the study is sensitive and specific and has good precision and stability.It could provide a new effective criterion and support for the early diagnosis and treatment of the AD patients.
出处
《中华检验医学杂志》
CAS
CSCD
北大核心
2012年第1期42-46,共5页
Chinese Journal of Laboratory Medicine
基金
基金项目：广东省自然科学基金资助项目（8151008901000035）
广东省科技计划项目资助课题（2010A030400006）
关键词
阿尔茨海默病
淀粉样Β蛋白
肽碎片
酶联免疫吸附测定
Alzheimer disease
Amyloid beta-protein
Peptide fragments
Enzyme-linkedimmunosorbent assay
