Article
Anti-fixed Leishmania chagasi promastigotes IgG antibodies detected by flow cytometry (FC-AFPA-IgG) as a tool for serodiagnosis and for post-therapeutic cure assessment in American visceral leishmaniasis
Registro en:
GARCIA, Lúcia Maria et al. Anti-fixed Leishmania chagasi promastigotes IgG antibodies detected by flow cytometry (FC-AFPA-IgG) as a tool for serodiagnosis and for post-therapeutic cure assessment in American visceral leishmaniasis. Journal of Immunological Methods, v. 350, n. 1–2, p. 36-45, 2009. doi.org/10.1016/j.jim.2009.07.004
1872-7905
10.1016/j.jim.2009.07.004
Autor
Garcia, Lucia Maria
Reis, Jordana Grazziela Alves Coelho dos
Magalhães, Vanessa Peruhype
Carvalho, Andréa Teixeira de
Rocha, Roberta Dias Rodrigues
Araújo, Márcio Sobreira Silva
Gomes, Izabelle Teixeira
Carvalho, Sílvio Fernando Guimarães
Dietze, Reynaldo
Lemos, Elenice Moreira
Andrade, Mariléia Chaves
Martins Filho, Olindo Assis
Resumen
Visceral leishmaniasis (VL) is a systemic infection, caused by an intracellular protozoan parasite belonging to the Leishmania donovani complex. The diagnosis of VL is complex because most clinical features are shared with other commonly occurring febrile hepatosplenic diseases that can be endemic along with VL A number of serological devices are available but still require improvement mainly due to residual post-therapeutic serology and the cross-reactivity with other Trypanosomatidae protozooses. This study intended to describe and evaluate the performance of an indirect immunofluorescence assay referred as flow cytometry anti-fixed Leishmania chagasi promastigote IgG antibodies (FC-AFPA-IgG) for serodiagnosis of VL and assessment of post-therapeutic cure. The sera reactivity is reported as the percentage of positive fluorescent parasite (PPFP) along the titration curve. The analysis of sera titration curve indicated the sera dilution 1/32,000 and the PPFP = 25% as the cut-off to segregate positive and negative results. Using these parameters, the FC-AFPA-IgG displayed outstanding sensitivity and specificity for diagnosis and post-therapeutic cure assessment purposes. The inter-test reproducibility of FC-AFPA-IgG was also verified, considering two independent Analysts and validated the results obtained by FC-AFPA-IgG. Moreover, the comparison between FC-AFPA-IgG and the conventional serologic test (ELISA) showed that besides the statistically analogous results with strong positive correlation the FC-AFPA-IgG displayed higher performance indexes. Further analysis demonstrated that while cross-reactivity was observed in 8% of samples tested by ELISA. no cross-reactivity was detected by FC-AFPA-IgG. Together, the findings presented in this study showed the potential of FC-AFPA-IgG in both diagnosis and post-therapeutic cure assessment of VL (C). 2099-12-31