金标法检测广州管圆线虫特异性IgG抗体的研究

Rapid detection of specific IgG antibody for Angiostrongylus cantonensis by dot immunogold filtration assay

目的探索简易、快速的金标免疫渗滤法检测广州管圆线虫特异性抗体的诊断价值。方法以广州管圆线虫成虫可溶性抗原点样于固相硝酸纤维素膜上,以胶体金-proteinA为标记物,采用自行设计的渗滤装置,检测病人血清中广州管圆线虫特异性IgG抗体。结果检测21人份广州管圆线虫病人血清,检出阳性19份,敏感性为90.5%(19/21);100人份健康人群血清2份阳性,假阳性率为2%(2/100);与旋毛虫病人、血吸虫病人血清交叉反应率分别为26.7%(8/30)、3.3%(1/30),未发现与肺吸虫、囊虫、华支睾吸虫、肺结核病人血清有交叉反应。结论金标免疫渗滤法快速检测血清中广州管圆线虫特异性IgG不仅操作简便、快速,结果判读容易,不需特殊仪器设备,而且敏感性高,有较好的辅助诊断价值,与旋毛虫病人血清存在交叉反应。

A simple and rapid method of immunogold filtration assay （DIGFA） was applied to detect the specific IgG antibody of Angiostrongylus cantonensis, in which crude extracts of adult worms of A. cantonensis was used as antigen and protein A was congugated with colloid gold as the detection marker. A special pad for DIGFA was designed according to the reaction procedure. It was found that the sensitivity and specificity detected by this immunoassay for the detection of the specific IgGantibody of A. cantonensis were demonstrated to be 90.5% （19/21） and 98.0% （98/100） respectively, however, there 26.7% （8/30） and 3.3 % （1/30） of cases showing cross-reactions with sera of patients with Trichinella spiralis infection and schistosomiasis respectively. No cross-reaction to sera of patinents with other infections of helminthiasis, such as cysticercosis, clonorchiasis and fasiolopsiasis as well as tuberculosis, could be found. It is apparent that this method of assay is not only rapid and simple without requirement of special instrument, but also rather sensitive and specific for the detection of the specific IgGantibody for A. cantonensis infection.