title: Immunoagglutination test to diagnose Chagas disease: comparison of different latex-antigen complexes.
abstract: OBJECTIVE
  To evaluate the diagnostic performance of novel latex-protein complexes obtained from different antigens of Trypanosoma cruzi through immunoagglutination test using a panel of T. cruzi-positive sera, leishmaniasis-positive sera and negative sera for both parasites.
  
  
  METHODS
  Complexes' behaviour using total parasite homogenate (TPH), two simple recombinant proteins (RP1 and RP5) and two chimeric recombinant proteins (CP1 and CP2) was comparatively evaluated. The area under ROC curves was used as an index of accuracy. Sensitivity, specificity and discrimination efficiency were assessed.
  
  
  RESULTS
  All recombinant antigens showed higher specificity than TPH. The lower specificity of TPH was mainly due to cross-reacting peptides between T. cruzi and Leishmania spp. In turn, all performance indicators were higher for CP1 and CP2 than for RP1 and RP5. The carboxylated latex-CP2 (C2-CP2) complex was able to detect antibodies against T. cruzi. The values of area under ROC curve (0.96), sensitivity (92.3%, 95% CI: 79.4-100.0%) and specificity (84.0%, 95% CI: 67.6-100.0%) indicate that the assay could be used as a screening test.
  
  
  CONCLUSIONS
  The C2-CP2 complex could be an important tool to carry out sero-epidemiological studies.
authors.affiliation: INTEC (Universidad Nacional del Litoral and CONICET), Santa Fe, Argentina.
authors.forename: Valeria S
authors.initials: VS
authors.lastname: Garcia
authors.forename: Verónica D G
authors.initials: VD
authors.lastname: Gonzalez
authors.forename: Ivan S
authors.initials: IS
authors.lastname: Marcipar
authors.forename: Luis M
authors.initials: LM
authors.lastname: Gugliotta
mesh_terms: D000913:Antibodies, Protozoan / Q000097:blood*; D000953:Antigens, Protozoan / Q000097:blood*; D014355:Chagas Disease / Q000175:diagnosis* / Q000276:immunology; D003429:Cross Reactions / Q000276:immunology; D006801:Humans; D007841:Latex Fixation Tests; D007891:Leishmania / Q000276:immunology; D012372:ROC Curve; D011994:Recombinant Proteins / Q000097:blood / Q000276:immunology; D012680:Sensitivity and Specificity; D014349:Trypanosoma cruzi / Q000276:immunology*
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D011994:Recombinant Proteins
keywords: Chagas disease; complejos látex-proteína; complexes latex-protéine; enfermedad de Chagas; immunodiagnosis; immunodiagnostique; inmunodiagnóstico; latex-protein complexes; maladie de Chagas