Detection of IgG Anti-Leishmania Antigen by Flow Cytometry as a Diagnostic Test for Cutaneous Leishmaniasis.
Diagnosis of cutaneous leishmaniasis (CL) relies on clinical presentation, parasite isolation, histopathologic evaluation and positive Montenegro skin test. However, the low amounts of parasites in the lesion of these individuals make parasite isolation and histopatologic diagnosis unreliable, often leading to false-negative results. Also, 15% of people living in endemic areas have sub-clinical infection characterized by positive Montenegro skin test, which may contribute to misdiagnosis. Although the main Leishmania killing mechanism is through cell-mediated immune response, antibodies against Leishmania antigens are found in infected individuals. Here our goal was to develop a new serological technique using polystyrene microspheres sensitized with soluble Leishmania antigens as a tool for the detection of IgG in serum from CL patients by flow cytometry. To validate the assay we carried out a comparative test (ELISA) commonly used as a diagnostic test for parasitic diseases. To determine cross-reactivity we used serum from patients with Chagas disease, caused by a trypanosome that has several proteins with high homology to those of the Leishmania genus. We observed that the flow cytometry technique was more sensitive than the ELISA, but, less specific. Our results show that the flow cytometry serologic test can be used to confirm CL cases in L. braziliensis transmission areas, however, presence of Chagas disease has to be ruled out in these individuals.
Laboratório de Imunologia, Instituto de Ciências da Saúde, Universidade Federal da Bahia, Salvador, Brazil.
Geraldo
G
Pedral-Sampaio
Serviço de Imunologia, Complexo Hospitalar Professor Edgard Santos, Universidade Federal da Bahia, Salvador, Brazil.
Jessé S
JS
Alves
Serviço de Imunologia, Complexo Hospitalar Professor Edgard Santos, Universidade Federal da Bahia, Salvador, Brazil.|Instituto Nacional de Ciências e Tecnologia - Doenças Tropicais - INCT-DT, Salvador, Brazil.
Albert
A
Schriefer
Serviço de Imunologia, Complexo Hospitalar Professor Edgard Santos, Universidade Federal da Bahia, Salvador, Brazil.
Andréa
A
Magalhães
Laboratório de Imunologia, Instituto de Ciências da Saúde, Universidade Federal da Bahia, Salvador, Brazil.
Roberto
R
Meyer
Division of Infectious Diseases, Weill Cornell Medical College, New York, United States of America.
Marshall J
MJ
Glesby
Serviço de Imunologia, Complexo Hospitalar Professor Edgard Santos, Universidade Federal da Bahia, Salvador, Brazil.|Instituto Nacional de Ciências e Tecnologia - Doenças Tropicais - INCT-DT, Salvador, Brazil.|Laboratório Avançado de Saúde Pública, Fiocruz - BA, Salvador, Brazil.
Edgar M
EM
Carvalho
Serviço de Imunologia, Complexo Hospitalar Professor Edgard Santos, Universidade Federal da Bahia, Salvador, Brazil.|Instituto Nacional de Ciências e Tecnologia - Doenças Tropicais - INCT-DT, Salvador, Brazil.|Laboratório Avançado de Saúde Pública, Fiocruz - BA, Salvador, Brazil.
Lucas P
LP
Carvalho
D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D016022:Case-Control Studies; D014355:Chagas Disease / Q000175:diagnosis / Q000276:immunology; D003429:Cross Reactions; D003951:Diagnostic Errors; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007892:Leishmania braziliensis / Q000276:immunology*; D016773:Leishmaniasis, Cutaneous / Q000175:diagnosis* / Q000276:immunology*; D012698:Serologic Tests / Q000379:methods
D000913:Antibodies, Protozoan; D007074:Immunoglobulin G