Publications by authors named "Danielle Marquete Vitelli-Avelar"

We performed a detailed analysis of immunophenotypic features of circulating leukocytes and spleen cells from cynomolgus macaques that had been naturally infected with , identifying their unique and shared characteristics in relation to cardiac histopathological lesion status. infected macaques were categorized into three groups: asymptomatic [CCC(-)], with mild chronic chagasic cardiopathy [CCC(+)], or with moderate chronic chagasic cardiopathy [CCC(++)]. Our findings demonstrated significant differences in innate and adaptive immunity cells of the peripheral blood and spleen compartments, by comparison with non-infected controls.

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Background: Non-human primates have been shown to be useful models for Chagas disease. We previously reported that natural T. cruzi infection of cynomolgus macaques triggers clinical features and immunophenotypic changes of peripheral blood leukocytes resembling those observed in human Chagas disease.

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Background: Cynomolgus macaques (Macaca fascicularis) represent a feasible model for research on Chagas disease since natural T. cruzi infection in these primates leads to clinical outcomes similar to those observed in humans. However, it is still unknown whether these clinical similarities are accompanied by equivalent immunological characteristics in the two species.

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Differential serological diagnosis of Chagas disease and leishmaniasis is difficult owing to cross-reactivity resulting from the fact that the parasites that cause these pathologies share antigenic epitopes. Even with optimized serological assays that use parasite-specific recombinant antigens, inconclusive test results continue to be a problem. Therefore, new serological tests with high sensitivity and specificity are needed.

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Background: Preeclampsia (PE) is associated with platelet activation, which may be involved in its pathogenesis promoting coagulation and mediating inflammation. We investigated whether the platelet activation status together with the frequency of platelet-leukocyte aggregates/PLA and monocyte tissue factor/TF expression could be used as laboratorial biomarkers for PE diagnosis and prognosis.

Methods: Ninety-seven women were evaluated including severe PE/sPE (N=15), mild PE/mPE (N=20), normotensive pregnant/NP (N=31) and non-pregnant women/nonP (N=31).

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Background: Benznidazole (Bz)-chemotherapy is recommended to prevent Chagas disease progression, despite its limited efficacy during chronic disease. However, the host mechanisms underlying these benefits still remain to be elucidated.

Methods: In this study, we have used short-term whole blood cultures to describe the cytokine profile of Bz-treated Indeterminate Chagas disease patients-(INDt) as compared to untreated patients-(IND).

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CD25(High) CD4+ regulatory T cells (Treg cells) have been described as key players in immune regulation, preventing infection-induced immune pathology and limiting collateral tissue damage caused by vigorous anti-parasite immune response. In this review, we summarize data obtained by the investigation of Treg cells in different clinical forms of Chagas' disease. Ex vivo immunophenotyping of whole blood, as well as after stimulation with Trypanosoma cruzi antigens, demonstrated that individuals in the indeterminate (IND) clinical form of the disease have a higher frequency of Treg cells, suggesting that an expansion of those cells could be beneficial, possibly by limiting strong cytotoxic activity and tissue damage.

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Treatment success of chronically infected Chagas disease patients is laborious and a positive prognosis often is made only after repetitive serological and/or parasitological examinations with continuous negative results. Recently, we have developed a non-conventional flow-cytometric method in order to detect immunoglobulin G antibodies against live trypomastigote forms of Trypanosoma cruzi and showed its usefulness in the prognosis of treatment success. In the present study, we investigated the performance of flow-cytometric anti-live trypomastigote IgG antibodies (FC-ALTA) and flow-cytometric anti-fixed epimastigote IgG antibodies (FC-AFEA), as well as conventional serological methods, for early monitoring of benznidazole treated Chagas disease patients, e.

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One of the challenges on immunodiagnostic of Chagas disease in endemic areas has been the search for more practical and safe antigenic preparation that provides tests with higher sensitivity and specificity, with low cross-reactivity. A new approach using fixed Trypanosoma cruzi epimastigotes to detect IgG reactivity was investigated previously. In order to continue this investigation, this study aimed at optimizing the flow cytometry-based method to the diagnosis of Chagas disease patients after specific chemotherapy.

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There is a general consensus that during chronic Trypanosoma cruzi infection, the host immune system induces complex processes to ensure the control of parasite growth while preserving the potential to mount and maintain a life-long controlled humoral and cellular immune response against the invading pathogen. This review summarises evidence in an attempt to elucidate 'what must be understood' to further clarify the role of innate immunity in the development/maintenance of clinical Chagas disease and the impact of etiological treatment on host immunity, highlighting the contributions of the innate immunity and regulatory T (Treg) cells. Recently, increasing focus on innate immunity suggest that chronic T.

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Immunological alterations associated with aging (immunosenescence) do not represent a simple unidirectional decline in all functions but develop as a complex remodeling of the immune system, involving multiple reorganization and developmentally regulated changes. In general, most data available about aging were obtained at particular age intervals and most of them come from Caucasian individuals from either Europe or the United States. Here, we report the frequencies of major lymphocyte subsets in healthy Brazilian individuals from 2 distinct geographic regions (Southeast and South) at several age intervals spanning a lifetime period (0-86 years).

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Pro-inflammatory immune response is usually associated with Chagas disease pathogenesis, but is also relevant to treatment effectiveness. Cross-sectional studies have suggested that this activated state may persist for years after therapeutic intervention. However, short-term longitudinal investigation has suggested that the Benznidazole treatment (Bz-treatment) leads to decreased immunological activation.

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We have recently developed a flow cytometric approach to detect anti-live trypomastigote and anti-fixed epimastigote IgG antibodies (FC-ALTA and FC-AFEA) in sera from individuals infected by Trypanosoma cruzi. Here, we present the first evaluation of the applicability of FC-AFEA-IgG as a diagnostic tool for Chagas disease. Performance analysis demonstrated that FC-AFEA-IgG has a sensitivity of 82% and a specificity of 100%.

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