The use of IgG antibodies in conventional and non-conventional immunodiagnostic tests for early prognosis after treatment of Chagas disease.

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.

Trypanosoma cruzi: desferrioxamine decreases mortality and parasitemia in infected mice through a trypanostatic effect.

Desferrioxamine (DFO) is a potent iron chelator that is also known to modulate inflammation and act as an efficient antioxidant under normal conditions and under oxidative stress. Many in vitro and in vivo studies have shown the efficacy of DFO in the treatment of viral, bacterial and protozoan infections. DFO is known to reduce the intensity of Trypanosoma cruzi infections in mice even during a course of therapy that is not effective in maintaining anaemia or low iron levels.

Influence of clinical status and parasite load on erythropoiesis and leucopoiesis in dogs naturally infected with leishmania (Leishmania) chagasi.

Background: The bone marrow is considered to be an important storage of parasites in Leishmania-infected dogs, although little is known about cellular genesis in this organ during canine visceral leishmaniasis (CVL).

Methodology/principal Findings: The aim of the present study was to evaluate changes in erythropoiesis and leucopoiesis in bone marrow aspirates from dogs naturally infected with Leishmania chagasi and presenting different clinical statuses and bone marrow parasite densities. The evolution of CVL from asymptomatic to symptomatic status was accompanied by increasing parasite density in the bone marrow.

Applicability of an optimized non-conventional flow cytometry method to detect anti-Trypanosoma cruzi immunoglobulin G for the serological diagnosis and cure assessment following chemotherapeutic treatment of Chagas disease.

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.

Understanding of the immunological heterogeneity of canine mammary carcinomas to provide immunophenotypic features of circulating leukocytes as clinically relevant prognostic biomarkers.

We have evaluated the phenotypic features of peripheral blood leukocytes as putative novel biomarkers with prognostic values to monitor canine mammary carcinomas. Female dogs were categorized into distinct groups, referred as mammary carcinoma in benign mixed tumor-MC-BMT and mammary carcinoma-MC. Our findings demonstrate that decreased percentage of B-cells along with increased frequency of NK-cells, CD8(+)T-cells, and CD8(+)CD5(Low+)T-cells beside higher T/B-cells and lower CD4(+)/CD8(+) ratio were the hallmarks of MC-BMT.

Immunological changes in canine peripheral blood leukocytes triggered by immunization with first or second generation vaccines against canine visceral leishmaniasis.

In this study, we summarized the major phenotypic/functional aspects of circulating leukocytes following canine immunization with Leishvaccine and Leishmune®. Our findings showed that Leishvaccine triggered early changes in the innate immunity (neutrophils and eosinophils) with late alterations on monocytes. Conversely, Leishmune(®) induced early phenotypic changes in both, neutrophils and monocytes.

Cytokine and transcription factor profiles in the skin of dogs naturally infected by Leishmania (Leishmania) chagasi presenting distinct cutaneous parasite density and clinical status.

The immune response in the skin of dogs infected with Leishmania chagasi and its association with distinct levels of tissue parasitism and clinical progression of canine visceral leishmaniasis (CVL) are poorly understood and limited studies are available. A detailed analysis of the profiles of cytokines (IFN-γ, IL-4, IL-5, IL-10, IL-12, IL-13, TGF-β1 and TNF-α) and transcription factors (T-bet, GATA-3 and FOXP3) in the skin of 35 naturally infected dogs was carried out using real-time PCR alongside determinations of skin parasite density and the clinical status of CVL. A mixed cytokine profile with high levels of expression of IFN-γ, TNF-α and IL-13 was determined in asymptomatic dogs.

Augmented plasma microparticles during acute Plasmodium vivax infection.

Background: In the last few years, the study of microparticles (MPs)--submicron vesicles released from cells upon activation or apoptosis--has gained growing interest in the field of inflammation and in infectious diseases. Their role in the human malaria parasite Plasmodium vivax remains unexplored. Because acute vivax malaria has been related to pro-inflammatory responses, the main hypothesis investigated in this study was that Plasmodium vivax infection is associated with elevated levels of circulating MPs, which may play a role during acute disease in non-immune patients.

Coinfection with different Trypanosoma cruzi strains interferes with the host immune response to infection.

A century after the discovery of Trypanosoma cruzi in a child living in Lassance, Minas Gerais, Brazil in 1909, many uncertainties remain with respect to factors determining the pathogenesis of Chagas disease (CD). Herein, we simultaneously investigate the contribution of both host and parasite factors during acute phase of infection in BALB/c mice infected with the JG and/or CL Brener T. cruzi strains.

Characterization of main cytokine sources from the innate and adaptive immune responses following primary 17DD yellow fever vaccination in adults.

The mechanisms of immune response following yellow fever (YF-17DD) vaccination are still poorly understood. In this study, we have performed a longitudinal investigation (days 0, 7, 15 and 30) to characterize the cytokine profile of innate and adaptive immunity following YF-17DD first-time vaccination. Data from non-stimulated cultures demonstrated a prominent participation of the innate immunity with increased frequency of TNF-α(+) neutrophils and IFN-γ(+) NK-cells at day 7 besides TNF-α(+) monocytes at day 7, day 15 and day 30.

Rural tourism: a risk factor for schistosomiasis transmission in Brazil.

This paper reports an outbreak of acute schistosomiasis among 38 tourists who rented a country house in the district of Igarapé, the metropolitan region of Belo Horizonte, Brazil, during a holiday period in 2006. A total number of 32 individuals were positive for Schistosoma mansoni. Results of stool examinations revealed individual S.

Seric chemokines and chemokine receptors in eosinophils during acute human schistosomiasis mansoni.

The recruitment of circulating eosinophils by chemokines and chemokine receptors plays an important role in the inflammation process in acute human schistosomiasis. Our main focus has been on the plasma chemokines (CXCL8/CCL2/CCL3/CCL24) and chemokine receptors (CCR2/CCR3/CCR5/CXCR1/CXCR2/CXCR3/CXCR4) expressed by circulating eosinophils from acute Schistosoma mansoni infected patients (ACT). Our studies compared ACT patients and healthy individuals as a control group.

Increase of reactive oxygen species by desferrioxamine during experimental Chagas' disease.

Oxidative stress is common in inflammatory processes associated with many diseases including Chagas' disease. The aim of the present study was to evaluate, in a murine model, biomarkers of oxidative stress together with components of the antioxidant system in order to provide an overview of the mechanism of action of the iron chelator desferrioxamine (DFO). The study population comprised 48 male Swiss mice, half of which were treated daily by intraperitoneal injection of DFO over a 35-day period, while half were administered sterile water in a similar manner.

Immunophenotypic features of tumor infiltrating lymphocytes from mammary carcinomas in female dogs associated with prognostic factors and survival rates.

Background: The immune system plays an important role in the multifactorial biologic system during the development of neoplasias. However, the involvement of the inflammatory response in the promotion/control of malignant cells is still controversial, and the cell subsets and the mechanisms involved are poorly investigated. The goal of this study was to characterize the clinical-pathological status and the immunophenotyping profile of tumor infiltrating lymphocytes and their association with the animal survival rates in canine mammary carcinomas.

Diagnostic tool based on an HTLV-1-Tax expression system in eukaryotic cells using a poxvirus vector.

Human T-lymphotropic virus 1 (HTLV-1) induces an immune-mediated inflammatory disease affecting the nervous system that eventually is accompanied by ocular, rheumatic and dermatologic manifestations (HTLV-1 associated myelopathy/tropical spastic paraparesis, or HAM/TSP). Proviral load and HTLV-1 protein expression, mainly of Tax, is correlated with disease progression and induction of host-virus equilibrium breakdown that, reportedly, involves the presence of Tax-specific cytotoxic T lymphocytes (CTL), T regulatory cells and anti-Tax antibodies. Based on knowledge of anti-Tax antibodies as markers of disease progression, the objectives of this study were both to design an infection/transfection system using the Vaccinia virus and a tax-encoding plasmid for the expression of Tax protein as well as to use this cell support to evaluate anti-Tax IgG by flow cytometry.

Clinical and immunological insights on severe, adverse neurotropic and viscerotropic disease following 17D yellow fever vaccination.

Yellow fever (YF) vaccines (17D-204 and 17DD) are well tolerated and cause very low rates of severe adverse events (YEL-SAE), such as serious allergic reactions, neurotropic adverse diseases (YEL-AND), and viscerotropic diseases (YEL-AVD). Viral and host factors have been postulated to explain the basis of YEL-SAE. However, the mechanisms underlying the occurrence of YEL-SAE remain unknown.

Innate immunity and regulatory T-cells in human Chagas disease: what must be understood?

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.

Profile of central and effector memory T cells in the progression of chronic human chagas disease.

Background: Chronic Chagas disease presents several different clinical manifestations ranging from asymptomatic to severe cardiac and/or digestive clinical forms. Several studies have demonstrated that immunoregulatory mechanisms are important processes for the control of the intense immune activity observed in the chronic phase. T cells play a critical role in parasite specific and non-specific immune response elicited by the host against Trypanosoma cruzi.

Anti-fixed Leishmania chagasi promastigotes IgG antibodies detected by flow cytometry (FC-AFPA-IgG) as a tool for serodiagnosis and for post-therapeutic cure assessment in American visceral leishmaniasis.

Visceral leishmaniasis (VL) is a systemic infection, caused by an intracellular protozoan parasite belonging to the Leishmania donovani complex. The diagnosis of VL is complex because most clinical features are shared with other commonly occurring febrile hepatosplenic diseases that can be endemic along with VL. A number of serological devices are available but still require improvement mainly due to residual post-therapeutic serology and the cross-reactivity with other Trypanosomatidae protozooses.

Hepatitis C virus screening and clinical monitoring of biomarkers in patients undergoing hemodialysis.

In this study, 395 volunteers were enrolled to investigate the seroprevalence of hepatitis C virus, the immunological and the alanine aminotransferase (ALT) biomarkers amongst hemodialysis patients, living in Manaus, Brazil. An overall seroprevalence of 13.9% was found in the hemodialysis patients.

T-cell-derived cytokines, nitric oxide production by peripheral blood monocytes and seric anti-Leishmania (Leishmania) chagasi IgG subclass patterns following immunization against canine visceral leishmaniasis using Leishvaccine and Leishmune.

It is generally accepted that distinct cytokine expression by the cellular immune response plays a critical role during the outcome of experimental as well as natural canine visceral Leishmaniasis (CVL). Despite the fact that immunoprophylaxis of CVL has become an important control strategy and protective immunity has been reported upon immunization with whole as well as purified Leishmania antigens, the cytokine profile of T-cells triggered by anti-CVL vaccines still remain to be determined. Herein, we have developed a cross-sectional analysis of German Shepherd dogs submitted to vaccination protocols with Leishvaccine (n=6) and Leishmune (n=6).

Systemic and compartmentalized immune response in canine visceral leishmaniasis.

Human visceral leishmaniasis (VL) and canine visceral leishmaniasis (CVL) are the most important emerging diseases with high prevalence in Latin American countries and are mainly caused by Leishmania (L.) chagasi (Syn=L. infantum).

Variation rhythms of lymphocyte subsets during healthy aging.

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).

Binding of excreted and/or secreted products of adult hookworms to human NK cells in Necator americanus-infected individuals from Brazil.

The impact of the interaction between excreted and/or secreted (ES) Necator americanus products and NK cells from Necator-infected individuals was analyzed. We investigated the binding of ES products to NK cells, the expression of NK cell receptors (CD56, CD159a/NKG2A, CD314/NKG2D, CD335/NKp46, and KLRF1/NKp80), the frequency of gamma interferon (IFN-gamma)-producing NK cells after whole-blood in vitro stimulation, and the capacity of N. americanus ES products to induce NK cell chemotaxis.

HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) inflammatory network.

HTLV-1 associated myelopathy/ tropical spastic paraparesis (HAM/TSP) is a systemic immune-mediated inflammatory disease and tissues other than nervous can be damaged, mainly ocular, rheumatic and dermatologic. Over 90% of HTLV-1-infected individuals remain lifelong asymptomatic and this retrovirus persists indefinitely in their CD4+ T-lymphocytes. The infection is maintained due to the proliferation of lymphocytes that harbor a provirus and express HTLV-1 proteins, particularly Tax, promoting an active and selective expansion of infected T cells.