title: Non-conventional flow cytometry approaches to detect anti-Trypanosoma cruzi immunoglobulin G in the clinical laboratory.
abstract: We have recently developed a flow cytometric approach to detect anti-live trypomastigote and anti-fixed epimastigote IgG antibodies (FC-ALTA and FC-AFEA) in sera from individuals infected by Trypanosoma cruzi. Here, we present the first evaluation of the applicability of FC-AFEA-IgG as a diagnostic tool for Chagas disease. Performance analysis demonstrated that FC-AFEA-IgG has a sensitivity of 82% and a specificity of 100%. The assessment for prognosis performed by FC-ALTA-IgG1 and FC-AFEA-IgG, after classification of chagasic patients as belonging to indeterminate (IND), cardiac (CARD) or digestive (DIG) clinical forms, showed that most of IND have higher amounts of IgG than individuals' carrying CARD or DIG Chagas disease. FC-AFEA-IgG was also evaluated as a method to monitor chemotherapy efficacy in individuals classified into three distinct categories: not treated (NT), treated but not cured (TNC), and treated and cured (TC). Performance analysis demonstrated that FC-AFEA-IgG has an extraordinary capacity as a serological criterion to assess cure after therapeutic intervention in Chagas disease. These results represent a great advance in the application of serological techniques for clinical investigations on Chagas disease, and they clearly define new directions and perspectives. We intend to continue this field research focusing our attention on the influence of the degree of clinical damage on the FC-ALTA-IgG1 and FC-AFEA-IgG reactivity.
authors.affiliation: Laboratório de Doença de Chagas, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz, Brazil. vitelli@cpqrr.fiocruz.br
authors.forename: Danielle Marquete
authors.initials: DM
authors.lastname: Vitelli-Avelar
authors.forename: Renato
authors.initials: R
authors.lastname: Sathler-Avelar
authors.forename: Ana Paula Barbosa
authors.initials: AP
authors.lastname: Wendling
authors.forename: Roberta Dias Rodrigues
authors.initials: RD
authors.lastname: Rocha
authors.forename: Andréa
authors.initials: A
authors.lastname: Teixeira-Carvalho
authors.forename: Natália Evelin
authors.initials: NE
authors.lastname: Martins
authors.forename: João Carlos Pinto
authors.initials: JC
authors.lastname: Dias
authors.forename: Anis
authors.initials: A
authors.lastname: Rassi
authors.forename: Alejandro Ostemayer
authors.initials: AO
authors.lastname: Luquetti
authors.forename: Silvana Maria
authors.initials: SM
authors.lastname: Elói-Santos
authors.forename: Olindo Assis
authors.initials: OA
authors.lastname: Martins-Filho
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D014355:Chagas Disease / Q000175:diagnosis* / Q000188:drug therapy / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D003429:Cross Reactions / Q000276:immunology; D005189:False Positive Reactions; D005434:Flow Cytometry / Q000379:methods*; D005557:Formaldehyde / Q000737:chemistry; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D007223:Infant; D016013:Likelihood Functions; D008875:Middle Aged; D011108:Polymers / Q000737:chemistry; D011237:Predictive Value of Tests; D011379:Prognosis; D012372:ROC Curve; D012680:Sensitivity and Specificity; D016707:Tissue Fixation; D016896:Treatment Outcome; D014349:Trypanosoma cruzi / Q000737:chemistry / Q000276:immunology*
chemical_list: D000913:Antibodies, Protozoan; D007074:Immunoglobulin G; D011108:Polymers; D005557:Formaldehyde; C003043:paraform