Here we found that the flow cytometry test was better able to discern between active infection and positive DTH alone than the ELISA test (specificity of 88

Here we found that the flow cytometry test was better able to discern between active infection and positive DTH alone than the ELISA test (specificity of 88.46% and 30.77%, respectively). CL is an endemic disease in more than 80 countries and to date there is no gold standard technique for the diagnosis of this disease. 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 genus. We observed that this flow cytometry technique was more sensitive than the ELISA, but, less specific. Our results show that this flow cytometry serologic test can be used to confirm CL cases in transmission areas, however, presence of Chagas disease has to be ruled out in these individuals. Introduction Cutaneous leishmaniasis (CL) caused by is characterized by the presence of one or more well-delineated ulcerated lesions that is mainly composed of lymphocytes, mononuclear phagocytes and plasma cells [1, 2]. In CL patients the immune response is usually predominantly mediated by mononuclear cells, which involve mechanisms associated with delayed type hypersensitivity with production of IFN-gamma and TNF [3C5]. This kind of response mediates parasite killing through activation of macrophages and also leads to tissue damage observed in these individuals [5]. The diagnosis of CL is mainly based on clinical observations and skin test; histopathologic or PCR techniques are usually used as confirmatory assessments [6C9]. However, due to the Rabbit Polyclonal to ICK low frequency of parasites in lesions of have been detected in CL patients, mainly due to differences in parasitic load, species involved, time since contamination and intrinsic (24S)-24,25-Dihydroxyvitamin D3 host factors [15C18]. Methods to evaluate the humoral immune response are mainly based on serologic surveys using soluble antigens, recombinant antigens and fixed parasites, such as indirect immunofluorescence, indirect hemaglutination and ELISA. Problems with the analysis of antibody titers by conventional serologic methods to detect contamination include cross-reactivity with other species of the Trypanosomatidae family, low sensitivity and lack of association with the presence of active contamination [19, 20]. Serological studies based (24S)-24,25-Dihydroxyvitamin D3 on flow cytometry using polystyrene microspheres coated with soluble antigens constitute a field with growth potential due to the increased sensitivity of this method [21, 22]. In the present study we have developed a serological technique using polystyrene microspheres sensitized with soluble antigen (SLA) for the detection of IgG antibodies in the serum of CL patients by flow cytometry and have compared this with an ELISA test. We show that this flow cytometry-based test has greater sensitivity compared to the ELISA test, though neither test has the capacity to distinguish between samples from and infected individuals. Materials and Methods Patients Participants of this study were from the Corte de Pedra endemic area in Northeastern Brazil, a transmission area where more than 1000 cases are diagnosed per year. The study populace consisted of 27 CL (24S)-24,25-Dihydroxyvitamin D3 patients, 26 household contacts of CL patients, with evidence of exposure to but without disease, (24S)-24,25-Dihydroxyvitamin D3 9 individuals with Chagas disease and 10 healthy subjects living in a non-endemic area. Leishmaniasis patients were diagnosed based on clinical presentation compatible with cutaneous leishmaniasis, positive Montenegro skin test and parasite isolation. Chagas disease patients were diagnosed by a serologic test to detect IgG to (Diagnostic Automation, INC, CA, USA). Individuals with evidence of exposure to but without disease were identified by positive delayed type hypersensitivity (DTHMontenegro skin test), IFN-gamma production to SLA and absence of lesions or history of leishmaniasis. All blood samples were collected before treatment of CL or Chagas disease had been started. To determine sensitivity, specificity, positive and negative predictive value we used 2 by 2 contingency tables containing: true positive; false positive; true negative; false unfavorable (Tables ?(Tables1,1, ?,22 (24S)-24,25-Dihydroxyvitamin D3 and ?and3).3). The number of true positive, false positive, true unfavorable and false unfavorable individuals from each group analysed are.