title: Deglycosylation of Toxocara excretory-secretory antigens improves the specificity of the serodiagnosis for human toxocariasis.
abstract: Serodiagnosis of human toxocariasis is difficult in tropical areas where other helminthiasis are endemic. Many studies have shown that glycans from helminths may be the responsible for cross-reactions in the immunoassays. In this study, we have evaluated the deglycosylation of the Toxocara canis excretory-secretory (TES) antigens for the detection of IgG antibodies using a panel of 228 serum samples (58 patients with toxocariasis, 75 patients with other helminth infections and 95 healthy individuals) by ELISA and Western blot assays. Our results showed that the deglycosylation of TES antigens resulted in a single fraction of 26 kDa (dTES) and was able to detect IgG antibodies with a sensitivity and specificity of 100% in both above-mentioned assays. The rate of cross-reactions, observed in ELISA with TES (13·3%), was significantly reduced (5·3%) when the dTES antigens were used. Likewise, the cross-reactivity observed with the fractions of 32, 55 and 70 kDa of the TES antigens was totally eliminated when the dTES were used in the Western blot. All these results showed that the deglycosylation of the TES antigens really improves the specificity of the serodiagnosis of human toxocariasis in endemic areas for helminth infections.
authors: Laboratório de Soroepidemiologia e Imunobiologia, Instituto de Medicina Tropical de São Paulo, Universidade de São Paulo, São Paulo, SP, Brazil.|Programa de Pós-graduação em Doenças Infecciosas e Parasitárias, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.|Departamento de Microbiologia Médica, Facultad de Medicina, Universidad Nacional Mayor de San Marcos, Lima, Peru.
authors: W H
authors: WH
authors: Roldán
authors: Laboratório de Soroepidemiologia e Imunobiologia, Instituto de Medicina Tropical de São Paulo, Universidade de São Paulo, São Paulo, SP, Brazil.
authors: G R
authors: GR
authors: Elefant
authors: Laboratório de Soroepidemiologia e Imunobiologia, Instituto de Medicina Tropical de São Paulo, Universidade de São Paulo, São Paulo, SP, Brazil.
authors: A W
authors: AW
authors: Ferreira
mesh_terms: D000818:Animals; D000947:Antigens, Helminth / Q000097:blood*; D015153:Blotting, Western; D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005260:Female; D006031:Glycosylation; D015801:Helminth Proteins / Q000097:blood*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D008297:Male; D012680:Sensitivity and Specificity; D014119:Toxocara / Q000502:physiology*; D014120:Toxocariasis / Q000175:diagnosis* / Q000276:immunology
chemical_list: D000947:Antigens, Helminth; D015801:Helminth Proteins; D007074:Immunoglobulin G; C045159:TES-26 protein, Toxocara canis
keywords: ELISA; excretory-secretory antigen; immunoglobulin; serodiagnosis; toxocariasis