用免疫磁珠法检测抗白念珠菌烯醇化酶抗体  

Establishment of an immunomagnetic bead assay for the detection of IgG antibody to Candida albicans enolase

作　　者：胡毓安[1,2] 史利宁[1,2] 李芳秋[1,2] 年娜[1,2] 马春芳[1,2] 孔小祥[1,2] 

机构地区：[1]南方医科大学南京临床医学院 [2]南京军区南京总医院临床中心实验科,南京210002

出　　处：《临床检验杂志》2013年第12期894-897,共4页Chinese Journal of Clinical Laboratory Science

基　　金：江苏省科技支撑计划-社会发展项目(BE2009673);南京军区医学科技创新重点课题(10Z027);国家自然科学基金青年科学基金项目(81302536)

摘　　要：目的建立检测人血清抗白念珠菌烯醇化酶(Eno)IgG类抗体的免疫磁珠法,并评估其在念珠菌血症诊断中的价值。方法将Eno重组蛋白耦联至磁性微珠上,以辣根过氧化物酶(HRP)标记的羊抗人IgG为二抗,优化免疫磁珠法的反应条件,考察其精密度和特异性。收集经血培养确诊的念珠菌血症患者(n=113)、念珠菌定植者(n=50)、细菌菌血症患者(n=30)和健康人对照者(n=100)血清,用免疫磁珠法测定抗Eno抗体,并与ELISA法结果进行比较。结果免疫磁珠法测定抗Eno抗体的批内、批间变异系数(CV)分别为8.2%和14.2%,重组Eno抗原对相应抗体的阻断率为91.6%。以吸光度(A)值0.29为cut off值时,诊断念珠菌血症的敏感性、特异性、阳性预测值和阴性预测值分别为80.5%、92.3%、90.1%和84.5%。免疫磁珠法的敏感性和特异性与ELISA法比较无统计学差异,但检测流程从37℃2.5 h缩短至常温1 h。结论免疫磁珠法检测抗Eno IgG类抗体简便、快捷、可靠,在侵袭性念珠菌感染研究中具有潜在的应用价值。Objective：To establish an immunomagnetic bead （IMB） assay for the detection of human serum specific IgG antibody to the enolase of Candida albicans, and evaluate its value in the diagnosis of candidemia. Methods：The immunomagnetic beads conjugated with recombinant enolase of Candida albicans were served as the solid phase, and HRP labeled goat anti human IgG as the second antibody. Then, the reaction conditions were optimized, and the accuracy and specificity of the established IMB assay evaluated. Serum samples from the patients with invasive candidemia（n=113）, Candidaspp. colonization（n=50）, bacteremia （n=30） and the health controls （n=100） were collected, and the IgG antibody to enolase in these samples was determined by the IMB assay and ELISA, respectively, and their results compared. Results：The intra- and inter-assay coefficients of variation of the IMB assay were 8.2% and 14.2%, respectively. There was 91.6% of antibody to enolase in sera blocked by recombinant enolase. With the absorbance value of 0.29 as the cut off, the sensitivity, specificity, positive predictive value and negative predictive value for diagnosing candidemia were 80.5%, 92.3%, 90.1% and 84.5%, respectively. There was no significant difference in diagnostic performance between the IMB assay and ELISA. However, the entire duration in the IMB assay （1 hour at room temperature） was shorter than that in ELISA （2.5 h at 37 ℃）. Conclusion：The established IMB assay is simple, rapid and reliable for the detection of IgG antibody to Candida albicans enolase, which has the potential application value in the research of invasive candidiasis.

关 键 词：自念珠茵 烯醇化酶 抗体 免疫磁珠法 念珠菌血症 

分 类 号：R446.5[医药卫生—诊断学]