El-Badry Ayman A
Department of Parasitology, Faculty of Medicine, Cairo University, Egypt.
J Egypt Soc Parasitol. 2009 Dec;39(3):757-68.
In order to overcome the false negative diagnosis of strongyloidiasis in the absence of rhabditiform larvae in stools, an ELISA-based Strongyloides stercoralis-specific coproantigen detection assay in stools of infected patients was evaluated. In a sandwich ELISA, a rabbit hyperimmune serum against S. stercoralis ES (excretory/secretory) adult antigen succeeded in capturing S. stercoralis coproantigen from infected patients and did not react with coproantigens prepared from the stool samples of patients infected with Schistosoma mansoni, Fasciola gigantica and Capillaria philippenensis. Coproantigen was able to detect anti-S. stercoralis IgG antibodies in sera of infected patients at the same OD level as produced with S. stercoralis E/S worm antigen using an indirect ELISA did not cross-react with sera from patients with S. mansoni, F. gigantica and C. philippenensis. S. stercoralis coproantigen detection proved a sensitive, simple, reliable and inexpensive ELISA-based, and an alternative to coproscopical methods in copropositive (with larvae in stool) and copronegative (without larvae in stool) stool samples. Fecal ELISA showed a positive relationship between copro-Ag and worm burdens, and considered a starting point for the development of species-specific copro-immunological diagnostic assays using monoclonal antibodies and dipstick technology.
为克服在粪便中无杆状蚴时粪类圆线虫病的假阴性诊断，对基于酶联免疫吸附测定（ELISA）的检测感染患者粪便中粪类圆线虫特异性粪抗原的方法进行了评估。在夹心ELISA中，一种针对粪类圆线虫排泄/分泌（ES）成虫抗原的兔超免疫血清成功捕获了感染患者粪便中的粪类圆线虫粪抗原，且不与感染曼氏血吸虫、巨片形吸虫和菲律宾毛细线虫患者粪便样本制备的粪抗原发生反应。粪抗原能够在与使用间接ELISA的粪类圆线虫ES/虫体抗原产生的相同光密度（OD）水平下检测感染患者血清中的抗粪类圆线虫IgG抗体，且不与曼氏血吸虫、巨片形吸虫和菲律宾毛细线虫患者的血清发生交叉反应。粪类圆线虫粪抗原检测证明是一种基于ELISA的灵敏、简单、可靠且廉价的方法，是粪检阳性（粪便中有幼虫）和粪检阴性（粪便中无幼虫）粪便样本中粪检方法的替代方法。粪便ELISA显示粪抗原与虫负荷之间呈正相关，并被视为使用单克隆抗体和试纸技术开发种特异性粪免疫诊断检测方法的起点。
