title: Serological diagnosis of Chagas disease: evaluation and characterisation of a low cost antigen with high sensitivity and specificity.
abstract: In spite of evident progress in the serology of Chagas disease, the requirement for new diagnostic antigens persists. We have evaluated different antigens obtained from Trypanosoma cruzi grown in medium rich in nutrients or under nutrient stress, autoclaved or sonicated and fractionated by differential centrifugation. The resulting antigens were evaluated for diagnosis of Chagas disease using ELISA. Immunofluorescence of the parasites demonstrated that nutrient stress induced changes in the distribution and density of antigens recognised by a pool of sera from experimentally infected mice. When evaluated using ELISA, it was evident that most fractions had good sensitivity but poor specificity. Surprisingly, the best specificity and sensitivity was observed with parasites cultured under nutrient stress and autoclaved. Furthermore this antigen had low cross reactivity with sera from other parasitic diseases, Leishmaniasis in particular. Western blot analysis demonstrated that autoclaving seems to non-specifically eliminate cross-reactive antigens. In conclusion, autoclaving epimastigotes of T. cruzi, after nutrient stress, allowed us to obtain an antigen that could be used in the serological diagnosis of Chagas disease.
authors.affiliation: Laboratorio de Fisiopatología (Nodo I LANPIP), Instituto de Biomedicina, Facultad de Medicina, Universidad Central de Venezuela, Caracas, Venezuela.
authors.forename: Yelitza
authors.initials: Y
authors.lastname: Campos
authors.forename: Luis
authors.initials: L
authors.lastname: Briceño
authors.forename: Kate
authors.initials: K
authors.lastname: Reina
authors.forename: Katherine
authors.initials: K
authors.lastname: Figarella
authors.forename: José Luis
authors.initials: JL
authors.lastname: Pérez
authors.forename: Walter
authors.initials: W
authors.lastname: Mosca
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood / Q000276:immunology*; D000953:Antigens, Protozoan; D015153:Blotting, Western; D014355:Chagas Disease / Q000175:diagnosis*; D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay; D005455:Fluorescent Antibody Technique; D006801:Humans; D051379:Mice; D012680:Sensitivity and Specificity; D014349:Trypanosoma cruzi / Q000276:immunology*
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan