Detection of IgG Anti- < i > Leishmania < /i > Antigen by Flow Cytometry as a Diagnostic Test for Cutaneous Leishmaniasis

by Geraldo Pedral-Sampaio, Jess é S. Alves, Albert Schriefer, Andréa Magalhães, Roberto Meyer, Marshall J. Glesby, Edgar M. Carvalho, Lucas P. Carvalho 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, oft en 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 mainLeishmania killing mechanism is through cell-mediated immune response, antibodies againstLeishmania antigens are found in infected individuals. Here our goal was to develop a new serological technique using polystyrene microspheres sensitized with solubleLeishmania 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 theLeishmania 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 c...
Source: PLoS One - Category: Biomedical Science Authors: Source Type: research