Non-conventional flow cytometry approaches to detect anti-Trypanosoma cruzi immunoglobulin G in the clinical laboratory.
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.
Vitelli-Avelar
Danielle Marquete
DM
Laboratório de Doença de Chagas, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz, Brazil. vitelli@cpqrr.fiocruz.br
Sathler-Avelar
Renato
R
Wendling
Ana Paula Barbosa
AP
Rocha
Roberta Dias Rodrigues
RD
Teixeira-Carvalho
Andréa
A
Martins
Natália Evelin
NE
Dias
João Carlos Pinto
JC
Rassi
Anis
A
Luquetti
Alejandro Ostemayer
AO
Elói-Santos
Silvana Maria
SM
Martins-Filho
Olindo Assis
OA
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*
D000913:Antibodies, Protozoan; D007074:Immunoglobulin G; D011108:Polymers; D005557:Formaldehyde; C003043:paraform