Benznidazole: Hero or villain of cellular immune response in chronic Chagas disease patients?

Although the treatment of chronic Chagas disease (CCD) patients with Benznidazole (Bz) is still controversial, its use may prevent or delay the progression of the disease to the most severe forms. One of the main factors that can influence the effectiveness of the treatment is the possible cooperation between drug effect and the host immune response. Herein, we evaluated the immune response of peripheral blood mononuclear cells (PBMCs) infected with Trypanosoma cruzi and submitted to Bz treatment. Blood samples of CCD patients (n = 7) and non-infected individuals (n = 6) were drawn to obtain PBMCs. After cell culture, the supernatants were harvested and stored, and the cell analyzed by flow cytometer. The results showed that Bz positively regulated the molecular process of cell activation (CD80) and antigen presentation (HLA-DR), increased phagocytosis receptor and macrophage activation (CD64), and did not induce an exacerbated immune response. In conclusion, these results highlight the relevance of using Bz that, despite not being a true hero, it is also not a villain, as it presents a wide range of pharmacological/immunological response interactions, important for the immune balance in the clinical progression of CCD.

Cytokine production in allergic and Trichuris trichiura-infected children from an urban region of the Brazilian northeast.

The relationship between the cellular immune response during Trichuris trichiura infection and asthma has not yet been established. In this study, the cytokines interleukin (IL)-2, IL-4, IL-6, IL-10, TNF-α, IFN-γ and IL-17A were evaluated in asthmatic children harboring T. trichiura. For this assessment, asthmatic and non-asthmatic children (ISAAC questionnaire) were submitted to parasitological tests and blood samples were cultured (mitogen stimulation) for cytokine measurements in the supernatant. Asthma frequencies were similar in infected and uninfected children, but IL-4, IL-6, TNF-α and IL-10 levels were high in the infected asthmatic children. Additionally, infected non-asthmatic children exhibited high levels of these cytokines in relation to uninfected non-asthmatic children; however, cytokine levels were lower when compared with infected and asthmatic children. Therefore, T. trichiura infection positively modulated the pro- and anti-inflammatory cytokines in asthmatic children, but a background of asthma seemed to narrow the production of cytokines induced by this helminth.

Evaluation of the immunomodulatory effect against splenocytes of Balb/c mice of biflorin obtained from Capraria biflora by a new isolation method

Abstract Biflorin (6,9-dimethyl-3-(4-methylpent-3-en-1-yl) benzo[de]chromene-7,8-dione) is a promising substance that has been increasingly studied in the past decades due to its diverse pharmacological properties (i.e. antitumor, antioxidant, antiinflamatory, antimicrobial activity etc.). Aiming the comprehension of its antitumoral activity we investigated the cell proliferation and cytotoxicity habilities of biflorin against mice splenocytes Balb/c. Biflorin was able to stimulate mice splenocytes Balb/c in 48 h of incubation at a concentration of 20.2 µM. Its immunostimulation promoted the production of cytokines such as: TNF-α, IFN-γ, IL-2, IL-6 and IL-17, inducing the immune profile toward a Th1 response. Moreover, an original method which led to an excellent yield with less processing time compared to the methods described in the literature was developed to obtain biflorin, from sawdust of Capraria biflora L., Scrophulariaceae. This method shows a great potential of increasing the production of this pharmacological active compound.

Immunomodulatory Effects of the Water-soluble Lectin from Moringa oleifera Seeds (WSMoL) on Human Peripheral Blood Mononuclear Cells (PBMC).

BACKGROUND: Moringa oleifera is used in traditional medicine as well as in food, cosmetic, and pharmaceutical industries. Water-soluble M. oleifera lectin (WSMoL) is an anionic protein isolated from the seeds of this tree. Until now, immune responses promoted by this lectin in human PBMC have not been investigated. OBJECTIVE: The main objective of this study was to investigate the immunomodulatory effects of WSMoL on human PBMC through measurement of lymphocytes subsets, cytokine and nitric oxide levels. METHODS: Human peripheral blood mononuclear cells (PBMC) were isolated through Ficoll technique, were incubated with WSMoL (10 µg/mL) for 24, 48 and 72 hours, and was performed immunophenotyping assay of lymphocytes and monocytes. Culture supernatants were used to determined cytokine and nitric oxide levels. Assays with cells subsets and cytokine production were performed through cytometry. Nitric oxide release assay was determinate by spectrophotometry. RESULTS: WSMoL induced the release of the cytokines TNF-α, IL-2, IL-6, IL-10 as well as nitric oxide. Incubation of PBMC with this lectin also led to activation of CD8+ T lymphocytes. CONCLUSION: WSMoL promotes immunomodulation in human PBMC inducing a potential wound healing profile and, in future in vivo assays, can be evaluated as adjuvant in immunosuppressive diseases and wound repair.

The Equivocal Role of Th17 Cells and Neutrophils on Immunopathogenesis of Leishmaniasis.

Advances in the understanding of leishmaniasis progression indicate that cellular interactions more complex than the Th1/Th2 paradigm define the course of infection. Th17 cells are a crucial modulator of adaptive immunity against Leishmania parasites acting mainly on neutrophil recruitment and playing a dual role at the site of infection. This review describes the roles of both these cell types in linking innate defense responses to the establishment of specific immunity. We focus on the Th17-neutrophil interaction as a crucial component of anti-Leishmania immunity, and the clinical evolution of cutaneous or visceral leishmaniasis. To date, information obtained through experimental models and patient evaluations suggests that the influence of the presence of interleukin (IL)-17 (the main cytokine produced by Th17 cells) and neutrophils during Leishmania infections is strictly dependent on the tissue (skin or liver/spleen) and parasite species. Also, the time at which neutrophils are recruited, and the persistence of IL-17 in the infection microenvironment, may also be significant. A clearer understanding of these interactions will enable better measurement of the influence of IL-17 and its regulators, and contribute to the identification of disease/resistance biomarkers.

IL17A Polymorphism Is Not Associated with Human T-Lymphotropic Virus 1-Associated Myelopathy/Tropical Spastic Paraparesis.

The human T-lymphotropic virus 1 (HTLV-1) is the causative agent of HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The present study investigated the association between the rs2275913 polymorphism in the IL17A gene and the development of HAM/TSP. Peripheral blood samples were collected from 116 patients (29 symptomatic patients with HAM/TSP and 87 asymptomatic) with a positive diagnosis of HTLV-1. The single nucleotide polymorphism genotyping was carried out by real time PCR using TaqMan probes. In addition, serum levels of IL-2, IFN-γ, TNF-α, IL-4, IL-6, IL-10, and IL-17 were measured in 64 infected individuals from the study (47 asymptomatic and 17 HAM/TSP), using cytometric bead array technique. No significant differences were found in genotypic and allelic frequencies between the groups. Analysis of cytokine levels showed highest concentrations of IFN-γ and TNF-α in HAM/TSP patients. The results of the present study, therefore, suggest a lack of association between the rs2275913 polymorphism in the IL17A gene and the presence of HAM/TSP.

Diagnosis of Chagas disease: what has been achieved? What remains to be done with regard to diagnosis and follow up studies?

In the acute phase and in the chronic forms of Chagas disease, the etiological diagnosis may be performed by detection of the parasite using direct or indirect parasitological methods and by the presence of antibodies in the serum by way of serological tests. Several techniques are easily available, ranging from the simplest wet smear preparation to immuno-enzymatic assays with recombinant antigens that will meet most diagnostic needs. Other tests under evaluation include a molecular test using polymerase chain reaction, which has shown promising results and may be used as a confirmatory test both in the acute and chronic phases of the disease. Better rapid tests are needed for diagnosis, some of which are already under evaluation. Additionally, there is a need for tools that can identify patients cured shortly after specific treatment. Other needs include a marker for prognosis and early diagnosis of congenital transmission.

Diagnosis of Chagas disease: what has been achieved? What remains to be done with regard to diagnosis and follow up studies?

In the acute phase and in the chronic forms of Chagas disease, the etiological diagnosis may be performed by detection of the parasite using direct or indirect parasitological methods and by the presence of antibodies in the serum by way of serological tests. Several techniques are easily available, ranging from the simplest wet smear preparation to immuno-enzymatic assays with recombinant antigens that will meet most diagnostic needs. Other tests under evaluation include a molecular test using polymerase chain reaction, which has shown promising results and may be used as a confirmatory test both in the acute and chronic phases of the disease. Better rapid tests are needed for diagnosis, some of which are already under evaluation. Additionally, there is a need for tools that can identify patients cured shortly after specific treatment. Other needs include a marker for prognosis and early diagnosis of congenital transmission.

Prevalência de infecção chagásica em doadores de sangue no estado de Pernambuco, Brasil / The prevalence of chagasic infection among blood donors in the State of Pernambuco, Brazil

A doença de Chagas é uma infecção sistêmica de evolução crônica cujo agente etiológico é o parasita Trypanosoma cruzi. O último relato encontrado sobre a soroprevalência da doença em doadores de sangue realizado na capital pernambucana, Recife, data de 1970, onde foi encontrada uma prevalência de 4,4 por cento em doadores de um hospital local. Devido à falta de informações divulgadas sobre a infecção por T. cruzi e sendo Pernambuco uma região endêmica para esta enfermidade, o presente estudo se propôs a analisar o perfil dos doadores de sangue do Hemocentro de Pernambuco (Hemope), que apresentaram reatividade para doença de Chagas, no período de 2002 a 2007. O perfil dos doadores inaptos foi avaliado de acordo com gênero, idade e procedência segundo as mesorregiões de Pernambuco. Foi encontrada uma prevalência de 0,17 por cento para doença de Chagas e 6,89 por cento das bolsas descartadas deveram-se a essa reatividade. Em relação ao gênero dos doadores, foi significativamente maior a contribuição dos homens (p<0,0001). A faixa etária de 18-30 anos apresentou menor quantidade de sorologias reativas (20,21 por cento). Foi verificado também que, na Região Metropolitana do Recife, a quantidade de reações inconclusivas foi estatisticamente maior que a quantidade de sorologias reagentes (p=0,0440). Desta forma, estudos epidemiológicos fornecem dados importantes no sentido de se avaliar diretamente o risco de transmissão de uma doença por transfusão sanguínea e permitem que também em regiões endêmicas se avalie a eficácia das medidas para o controle vetorial.

Chagas disease is a systemic infection with a chronic onset transmitted by Trypanosoma cruzi. The last study conducted in Recife, capital of Pernambuco state, was carried out during 1970. At that time a prevalence of 4.4 percent was found among blood donors of a local hospital. Due to the lack of epidemiology data on T. cruzi infection and as Pernambuco is an endemic region, the present study describes the profile of blood donors who presented reactivity for Chagas disease during the period of 2002 to 2007 in the state's blood bank (Hemope). The profile of unsuitable donors was evaluated according to gender, age and according to the meso-regions of Pernambuco. A prevalence of 0.17 percent was found for Chagas disease, whereas 6.89 percent of the rejected blood bags were due to this reactivity. As far as gender is concerned, the reactivity of men was higher than that of women (p<0.0001). Additionally, the age group between 18-30 years was less infected (20.21 percent). On analyzing the reactivity in each one of the meso-regions of the state, it was found that, in the Metropolitan Region of Recife, the number of inconclusive reaction cases was statistically higher than the number of reactive serology cases (p=0.0440). Thus, epidemiological studies provide important data to indirectly evaluate the risk of blood-borne diseases and allow indirect evaluation of the effectiveness of vectorial control measures in endemic regions.

Cellular immune response from Chagasic patients to CRA or FRA recombinant antigens of Trypanosoma cruzi.

We propose to analyze the relation between the cellular immune response of Chagas' disease patients after in vitro stimulation of peripheral blood mononuclear cells (PBMC) with recombinant antigens cytoplasmatic repetitive antigen (CRA) or flagellar repetitive antigen (FRA) of T. cruzi and the chronic clinical forms of disease. Cells were stimulated using phytohemagglutinin, CRA, FRA, or a soluble antigen of Epimastigota (Ag-Epi) for 24 hr, 72 hr, or 6 days. The proliferation of cells was evaluated after 6 days of culture by quantification of incorporated 3H-thymidine. Cytokines were measured in the supernatants obtained after 24 hr (tumor necrosis factor [TNF]-alpha and interleukin [IL]-4), 72 hr (IL-10), and 6 days (interferon [IFN]-gamma) using enzyme-linked immunosorbent assay (ELISA). Cells of the Chagas patients stimulated with the recombinant antigens exhibited higher proliferation responses compared with that of non-Chagas (NC) individuals. However, when proliferation was compared between patients with the cardiac form (CF) or indeterminate form (IF), it was not possible to establish a difference in the response. So far as the cytokines secreted in the culture supernatants after stimulation in vitro with T. cruzi antigens were concerned, the results showed that CRA, as well as Epi-Ag, were able to stimulate the production of TNF-alpha and IFN-gamma in Chagas patients as compared with NC individuals. However, the cytokine levels after stimulation with the T. cruzi antigens were not different between the patients with CF and IF. CRA was capable of inducing a T helper type 1 (Th1) immune response, with elevated production of TNF-alpha and IFN-gamma in Chagas patients that are carriers of CF and IF clinical forms.

Screening of diseases transmissible by blood in recipients prior to transfusion at a university hospital in the northeast of Brazil / Triagem de doenças transmissíveis por sangue em receptores de um hospital universitário no nordeste do Brasil, antes da transfusão

The Brazilian Ministry of Health has made tests for HIV1 and HIV2, HTLV I and HTLV II, HCV, HBV, T. cruzi, T. pallidum and Plasmodium in endemic areas, mandatory for all blood collection bags used in the country. However, blood-borne infectious diseases are not investigated in blood recipients before transfusion. For this study, a serological evaluation of recipients before transfusion was carried out. Prior to transfusion, serum samples from 159 blood recipients were analyzed using the same tests used in the serological screening of blood donors. The blood recipients were divided into three groups: Group 1 (G1), patients who had never received blood, Group 2 (G2), patients who had received multiple transfusions and Group 3 (G3) one-off recipients. SPSS v.8 was used for statistical analysis. Values of p<0.05 were taken to be significant. The results showed that 62 blood recipients tested positively for one or more blood-borne infectious diseases. In addition, several recipients were unaware of their serological status before the transfusion. The identification of blood-borne infectious diseases in recipients before transfusion could avoid the State being held responsible by recipients who were unaware that they were carriers of such diseases and only found out about their contamination after transfusion.

O Ministério da Saúde brasileiro determina a realização de testes sorológicos para HIV 1 e 2, HTLV I e II, HCV, HBV, T. cruzi, T. pallidum e Plasmodium nas áreas endêmicas, em todas as bolsas de coleta de sangue utilizadas no País. Entretanto, as doenças infecciosas transmissíveis através do sangue não são inves­tigadas nos receptores de sangue (RS) antes da transfusão. Neste estudo, realizamos uma avaliação sorológica dos RS anterior à transfusão. Amostras de soro de 159 RS foram analisadas aplicando-se os mesmos testes utilizados na triagem soro­lógica dos doadores de sangue. Os RS foram divididos em três grupos: Grupo 1 (G1), pacientes que nunca receberam sangue, Grupo 2 (G2), pacientes politransfundidos e Grupo 3 (G3) receptores eventuais. Para a análise estatística utilizou-se o pro­grama SPSS v.8. Valores de p<0,05 foram considerados signi­ficantes. Os resultados mostraram que 62 RS apresentaram positividade para uma ou mais doenças infecciosas trans­missíveis pelo sangue. Além disso, vários RS desconheciam seu estado sorológico anterior à transfusão. A identificação de doenças infecciosas transmissíveis pelo sangue em RS anterior à transfusão poderia evitar a responsabilidade do Estado pelos RS que desconheciam ser portadores de tais doenças e apenas tiveram conhecimento de sua contaminação após a transfusão.

Humoral and cellular immune responses in BALB/c and C57BL/6 mice immunized with cytoplasmic (CRA) and flagellar (FRA) recombinant repetitive antigens, in acute experimental Trypanosoma cruzi infection.

In previous studies, cytoplasmic repetitive antigen (CRA) and flagellar repetitive antigen (FRA) proteins induced specific humoral and cellular immune responses in susceptible and resistant mice in the absence of Trypanosoma cruzi infection with a significant induction of the Interferon-gamma (IFN-gamma) production in those animals. In this follow-up paper, the immunostimulatory and protective effects of these proteins were evaluated by immunizing with CRA or FRA antigens, BALB/c and C57BL/6 mice and challenging with a T. cruzi (Y strain). Both proteins induced humoral response with high levels of IgG isotypes as well as cellular immunity with high levels of IFN-gamma when compared to controls. However, the lymphocyte proliferative response was minimal. The survival rate at 30 days post-infection was significant in CRA (60%) or FRA (50%)--immunized BALB/c mice and CRA (83.3%)--immunized C57BL/6 mice. Taken as a whole these findings indicate that CRA and FRA are immunogenic and potentially important for protective immunity.

Avaliação do perfil sócio-demográfico dos receptores de sangue do Hospital Oswaldo Cruz da Universidade de Pernambuco / Evaluation of the social demographic profile from the Hospital Universitário Oswaldo Cruz (HUOC) - Brazil

O objetivo do presente trabalho foi avaliar o perfil sócio-demográfico dos receptores de sangue (RS) internados no Hospital Universitário Oswaldo Cruz (HUOC) da Universidade de Pernambuco-UPE. O estudo foi realizado nos RS (n=172) no período de fevereiro a maio de 2003, quando os pacientes foram submetidos ao instrumento de coleta de dados. O trabalho foi aprovado pela comissão de Ética do Centro de Pesquisa Aggeu Magalhães-CpqAM. O perfil sócio-demográfico do RS mostrou que a idade média foi de 32,2 anos, 46,5por cento do sexo masculino e 53,5por cento do sexo feminino, 43,0por cento casados, 37,0por cento solteiros, 20,0 por cento outros. Quanto ao grau de escolaridade, 65,3por cento tinham ensino fundamental. Apenas 22,6por cento resideiam na cidade do Recife e 49,1 eram oriundos de outros municípios e estados do Brasil, e 57,2por cento não estam exercendo atividade trabalhista. A baixa escolaridade encontrada no RS (65,3por cento com apenas o primeiro grau) e a ausência de atividade laborativa (57,2por cento) pode dificultar o entendimento da necessidade de reposição de estoques de sngue. Os dados obtidos no presente trabalho poderão ser utilizados para auxiliar no planejamento estrategico na política de captação de doadores de sangue de reposição para o HUOC