曼氏裂头蚴可溶性抗原DIGFA法快速检测特异性抗体的潜在诊断价值

The potential of rapid detection for specific antibodies in diagnosing sparganosis using plerocercoid soluble antigen

目的探索曼氏裂头蚴可溶性抗原金标免疫渗滤法快速检测曼氏裂头蚴特异性抗体的免疫诊断价值。方法从自然感染的青蛙中分离出曼氏裂头蚴,经口感染小鼠;于感染后第7周剖杀小鼠,收集鼠血清和虫体并计数。以曼氏裂头蚴可溶性抗原(PSA)为探针建立PSA-DIGFA,分别检测曼氏裂头蚴感染小鼠、健康小鼠、健康人群及其他寄生虫感染者血清中特异性抗体,并与常规ELISA法进行平行检测和比较。结果DIGFA法检测感染小鼠血清中特异性抗体的敏感性为100%(49/49)、特异性为100%(30/30),与ELISA法检测结果相同;不同虫荷数感染鼠间抗体水平差异无显著性(P>0.05),感染鼠与正常鼠之间抗体水平差异有显著性(P<0.01)。PSA-DIGFA检测健康人群血清100人份均为阴性,检测囊虫、包虫、旋毛虫、肺吸虫、华支睾吸虫病病人血清的阳性率分别为42.5%(17/40)、10.0%(2/20)、20.0%(5/25),80.0%(8/10)、8.0%(2/25)。结论用曼氏裂头蚴粗抗原检测感染动物血清中特异性抗体具有较好的敏感性和特异性,但与其他蠕虫感染存在较高的交叉反应。不同虫荷数感染鼠均产生较高水平抗体,组间差异无显著性。DIGFA法与ELISA法检测的敏感性和特异性相同,但前者更为简便、快速,无需特殊仪器设备,可单份检测,适合寄生虫病的临床检验和流行病学调查。若能进一步纯化检测用抗原,减少与其他蠕虫间的交叉反应,有潜在的应用价值。

Objective To evaluate the potential of rapid detection for antibodies using plerocercoid soluble antigen/ （PSA） in diagnosing sparganosis. Methods Plerocercoids mansoni was collected from naturally infected frogs. Each＇ mouse was fed five living pleroeereoids and sacrificed on seven weeks post-infection. Sera and pleroeereoids were eolleeted and count. Dot immunogold filtration assay （DIGFA） was developed using pleroeereoid soluble antigen （PSA） as probe. Specific antibodies in sera from infected mice, healthy mice, healthy people and other parasitic patients were detected by PSA-DIGFA, respectively. PSA-ELISA was carried out in parallel with DIGFA. Results Both of DIGFA and ELISA showed sensitivity with 100% in 49 infected mice and specificity with 100%in 30 normal mice. There was no significant difference among antibody levels of infected mice with different burden of pleroeereoid（P〉0.05）. The levels of antibodies in sera of infected mice were much higher than that of healthy mice（P〈0.01）. All 100 healthy persons showed negative while 42.5%（17/40） cases of eystieereosis, 10.0% （2/20） cases of eehinoeoeeosis, 20.0% （5/25） cases of trichinosis, 80.0%（8/10） cases of paragonimiasis, and 8.0%（2/25） cases of elonorehiasis were positive, respectively. Conclusion PSA-DIGFA showed high sensitivity and specificity in detecting specific antibodies in sera from infected mice. However, there were high cross-reactions with antibodies in sera from other patients. One worm burden could induce high levels of antibodies. The results of DIGFA were similar to those of routine ELISA, but the former was more handy and rapid without any specific instrumentation. DIGFA is a potential field-applicable immunoassay for diagnosis and epidemiologieal investigation of sparganosis if PSA could be purified to reduce the cross-reaction.