title: Development of Ss-NIE-1 recombinant antigen based assays for immunodiagnosis of strongyloidiasis.
abstract: Strongyloides stercoralis is a widely distributed parasite that infects 30 to 100 million people worldwide. In the United States strongyloidiasis is recognized as an important infection in immigrants and refugees. Public health and commercial reference laboratories need a simple and reliable method for diagnosis of strongyloidiasis to identify and treat cases and to prevent transmission. The recognized laboratory test of choice for diagnosis of strongyloidiasis is detection of disease specific antibodies, most commonly using a crude parasite extract for detection of IgG antibodies. Recently, a luciferase tagged recombinant protein of S. stercoralis, Ss-NIE-1, has been used in a luciferase immunoprecipitation system (LIPS) to detect IgG and IgG4 specific antibodies. To promote wider adoption of immunoassays for strongyloidiasis, we used the Ss-NIE-1 recombinant antigen without the luciferase tag and developed ELISA and fluorescent bead (Luminex) assays to detect S. stercoralis specific IgG4. We evaluated the assays using well-characterized sera from persons with or without presumed strongyloidiasis. The sensitivity and specificity of Ss-NIE-1 IgG4 ELISA were 95% and 93%, respectively. For the IgG4 Luminex assay, the sensitivity and specificity were 93% and 95%, respectively. Specific IgG4 antibody decreased after treatment in a manner that was similar to the decrease of specific IgG measured in the crude IgG ELISA. The sensitivities of the Ss-NIE-1 IgG4 ELISA and Luminex assays were comparable to the crude IgG ELISA but with improved specificities. However, the Ss-NIE-1 based assays are not dependent on native parasite materials and can be performed using widely available laboratory equipment. In conclusion, these newly developed Ss-NIE-1 based immunoassays can be readily adopted by public health and commercial reference laboratories for routine screening and clinical diagnosis of S. stercoralis infection in refugees and immigrants in the United States.
authors: Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors: Lisa N
authors: LN
authors: Rascoe
authors: Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors: Courtney
authors: C
authors: Price
authors: Emory College, Emory University, Atlanta, Georgia, United States of America.
authors: Sun Hee
authors: SH
authors: Shin
authors: Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors: Isabel
authors: I
authors: McAuliffe
authors: Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Controls and Prevention, Atlanta, Georgia, United States of America.
authors: Jeffrey W
authors: JW
authors: Priest
authors: Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors: Sukwan
authors: S
authors: Handali
mesh_terms: D000818:Animals; D000909:Antibodies, Helminth / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D015801:Helminth Proteins / Q000302:isolation & purification*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007159:Immunologic Tests; D047468:Immunoprecipitation; D008156:Luciferases; D011994:Recombinant Proteins; D012680:Sensitivity and Specificity; D017171:Strongyloides stercoralis / Q000302:isolation & purification*; D013322:Strongyloidiasis / Q000175:diagnosis*
chemical_list: D000909:Antibodies, Helminth; D015801:Helminth Proteins; D007074:Immunoglobulin G; D011994:Recombinant Proteins; D008156:Luciferases