Upgrading the flow-cytometric analysis of anti-Leishmania immunoglobulins for the diagnosis of American tegumentary leishmaniasis.
We have previously described a flow cytometry-based assay to detect anti-live Leishmania (Viania) braziliensis promastigote antibodies (FC-ALPA) with prominent performance of FC-ALPA to diagnosis American tegumentary leishmaniasis (ATL). However, the laboriousness to work with live parasites represented the major drawback for using FC-ALPA in routine clinical laboratory. Herein, we have presented an upgraded technology using fixed Leishmania (Leishmania) amazonensis promastigotes as antigen (FC-AFPA). Our data demonstrated that FC-AFPA-IgG displays outstanding performance for ATL diagnosis with high sensitivity (99%) and specificity (100%). Moreover, Likelihood Ratio indicated that positive results (LR+) has an infinite times more chance to come from ATL than from non-infected individuals (NI). Despite the high frequency of cross-reactivity with putative ATL co-endemic diseases, including visceral leishmaniasis, Chagas disease and malaria, FC-AFPA-IgG showed remarkable potential for differential diagnosis with other dermatological illnesses such as leprosy and sporotrichosis. FC-AFPA-IgG subclasses analysis revealed that LTA is characterized by IgG1>IgG3>IgG2 = IgG4 anti-L. amazonensis profiling, electing FC-AFPA-IgG1 and IgG3 with better performances to diagnosis ATL diagnosis. Additionally, FC-AFPA-IgG3 showed to be a better diagnostic tool in endemic areas for malarial disease. Despite the substantial advance to work with fixed promastigotes that contributes to its higher sensitivity, the lower specificity of FC-AFPA represented the major flaws as compared to FC-ALPA, suggesting that further improvement is still required to minimize the cross-reactivity with trypanosomatidae infections. Perspectives for using a flow cytometry multiplex based methodology to simultaneously assess anti-L. amazonensis, anti-L. chagasi and anti-Trypanosoma cruzi IgG reactivity is currently under investigation.
Laboratório de Leishmanioses, Núcleo de Doenças Infecciosas, Universidade Federal do Espírito Santo, Vitória, ES, Brazil.
Jauber Fornaciari
JF
Pissinate
Izabelle Teixeira
IT
Gomes
Vanessa
V
Peruhype-Magalhães
Reynaldo
R
Dietze
Olindo Assis
OA
Martins-Filho
Elenice Moreira
EM
Lemos
D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D003429:Cross Reactions; D003937:Diagnosis, Differential; D019353:Endemic Diseases; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007894:Leishmania mexicana / Q000276:immunology*; D016773:Leishmaniasis, Cutaneous / Q000175:diagnosis* / Q000276:immunology; D008288:Malaria / Q000453:epidemiology; D012680:Sensitivity and Specificity
D000913:Antibodies, Protozoan; D007074:Immunoglobulin G