Giovane Rodrigo Sousa

Plasma cytokine expression is associated with cardiac morbidity in chagas disease.

The expression of immune response appears to be associated with morbidity in Chagas disease. However, the studies in this field have usually employed small samples of patients and statistical analyses that do not consider the wide dispersion of cytokine production observed in these patients. The aim of this study was to evaluate the plasma cytokine levels in well-defined clinical polar groups of chagasic patients divided into categories that better reflect the wide cytokine profile and its relationship with morbidity. Patients infected with Trypanosoma cruzi (T. cruzi) were grouped as indeterminate (IND) and cardiac (CARD) forms ranging from 23 to 69 years of age (mean of 45.6±11.25). The IND group included 82 individuals, ranging from 24 to 66 years of age (mean of 39.6±10.3). The CARD group included 94 patients ranging from 23 to 69 years of age (mean of 48±12.52) presenting dilated cardiomyopathy. None of the patients have undergone chemotherapeutic treatment, nor had been previously treated for T. cruzi infection. Healthy non-chagasic individuals, ranging from 29 to 55 years of age (mean of 42.6±8.8) were included as a control group (NI). IND patients have a higher intensity of interleukin 10 (IL-10) expression when compared with individuals in the other groups. By contrast, inflammatory cytokine expression, such as interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), and interleukin 1 beta (IL-1β), proved to be the highest in the CARD group. Correlation analysis showed that higher IL-10 expression was associated with better cardiac function, as determined by left ventricular ejection fraction and left ventricular diastolic diameter values. Altogether, these findings reinforce the concept that a fine balance between regulatory and inflammatory cytokines represents a key element in the establishment of distinct forms of chronic Chagas disease.

Matrix Metalloproteinases 2 and 9 Are Differentially Expressed in Patients with Indeterminate and Cardiac Clinical Forms of Chagas Disease

ABSTRACT Dilated chronic cardiomyopathy (DCC) from Chagas disease is associated with myocardial remodeling and interstitial fibrosis, resulting in extracellular matrix (ECM) changes. In this study, we characterized for the first time the serum matrix metalloproteinase 2 (MMP-2) and MMP-9 levels, as well as their main cell sources in peripheral blood mononuclear cells from patients presenting with the indeterminate (IND) or cardiac (CARD) clinical form of Chagas disease. Our results showed that serum levels of MMP-9 are associated with the severity of Chagas disease. The analysis of MMP production by T lymphocytes showed that CD8+ T cells are the main mononuclear leukocyte source of both MMP-2 and MMP-9 molecules. Using a new 3-dimensional model of fibrosis, we observed that sera from patients with Chagas disease induced an increase in the extracellular matrix components in cardiac spheroids. Furthermore, MMP-2 and MMP-9 showed different correlations with matrix proteins and inflammatory cytokines in patients with Chagas disease. Our results suggest that MMP-2 and MMP-9 show distinct activities in Chagas disease pathogenesis. While MMP-9 seems to be involved in the inflammation and cardiac remodeling of Chagas disease, MMP-2 does not correlate with inflammatory molecules.

Differential Expression of Matrix Metalloproteinases 2, 9 and Cytokines by Neutrophils and Monocytes in the Clinical Forms of Chagas Disease.

Dilated cardiomyopathy, the most severe manifestation in chronic phase of Chagas disease, affects about 30% of patients and is characterized by myocardial dysfunction and interstitial fibrosis due to extracellular matrix (ECM) remodeling. ECM remodeling is regulated by proteolytic enzymes such as matrix metalloproteinases (MMPs) and cytokines produced by immune cells, including phagocytes. We evaluated by flow cytometry the expression of MMP-2, MMP-9, IL-1β, TNF-α, TGF-β and IL-10 by neutrophils and monocytes from patients with indeterminate (IND) and cardiac (CARD) clinical forms of Chagas disease and non-infected individuals (NI), before and after in vitro stimulation with Trypanosoma cruzi antigens. Our results showed an important contribution of neutrophils for MMPs production, while monocytes seemed to be involved in cytokine production. The results showed that neutrophils and monocytes from IND and CARD patients had higher intracellular levels of MMP-2 and MMP-9 than NI individuals. On the other hand, T. cruzi derived-antigens promote a differential expression of MMP-2 and MMP-9 in patients with Chagas disease and may regulate MMPs expression in neutrophils and monocytes, mainly when a cardiac alteration is not present. Our data also showed that in the presence of T. cruzi derived-antigens the production of cytokines by neutrophils and monocytes, but mainly by monocytes, may be intensified. Correlation analysis demonstrated that MMP-2 had a positive correlation with IL-10 and a negative correlation with IL-1β, whereas MMP-9 showed a negative correlation with IL-10. We also observed that IND patients presented a greater percentage of high producer cells of regulatory molecules when compared to CARD patients, indicating a different pattern in the immune response. Our data suggest that MMPs and cytokines produced by neutrophils and monocytes are important contributors for cardiac remodeling and may be an interesting target for new biomarker research.

The role of interleukin 17-mediated immune response in Chagas disease: High level is correlated with better left ventricular function

Interleukin 17A (IL-17A) has been associated with protective rather than pathogenic response in Chagas disease (ChD). However, it is not established whether or not IL-17A-mediated immune response is correlated with patient’s left ventricular (LV) function in ChD. To address this question we have gathered cardiac functional parameters from ChD patients and analysed the possible relationship between their plasma IL-17A levels and LV function. Plasma IL-17A levels were measured by BD Cytometric Bead Array (CBA) in 240 patients with positive specific serology for Trypanosoma cruzi (T. cruzi) grouped as indeterminate (IND) and Chagas cardiomyopathy (CARD) forms. The levels of IL-17A in ChD patients were compared with 32 healthy individuals, mean age of 39 years, 50% male, that were also included as a control group (non-infected [NI]). The overall mean age of ChD patients was 46 years and 52% were male. The IND group included 95 asymptomatic patients, with ages ranging from 27 to 69 years (mean of 43 years), and 42.1% of them were male. The CARD group included 145 patients, which 58.6% were male, with ages ranging from 23 to 67 years (mean of 49). The IND group presented substantially higher levels of IL-17A, median of 26.16 (3.66–48.33) as compared to both the CARD group, median of 13.89 (3.87–34.54) (P <0.0001), and the NI group, median of 10.78 (6.23–22.26) (P <0.0001). The data analysis demonstrated that the IND group comprises a significantly greater proportion (P <0.001) of high IL-17A producers (52.6%, 50 of 95 subjects) than do the other groups. A significant direct correlation was verified between IL-17A levels and cardiac function expressed by LV ejection fraction (LVEF), LV diastolic diameter (LVDd), and body surface area (BSA)-indexed LVDd as well as ratio of the early diastolic transmitral flow velocity to early diastolic mitral annular velocity (E/e’) in both groups. We demonstrated that plasma IL-17A levels has an accurate sensitivity and specificity to predict heart failure in serology-positive patients and might be a useful parameter to distinguish patients with or without cardiac impairment. This study indicates a consistent relationship between high expression of IL-17A and better LV in human chronic ChD. Our data raise the possibility that IL-17A plays an important immunomodulatory role in the chronic phase of ChD and might be involved in protection against myocardial damage.

Exercise-induced ventricular arrhythmias and vagal dysfunction in Chagas disease patients with no apparent cardiac involvement

INTRODUCTION Exercise-induced ventricular arrhythmia (EIVA) and autonomic imbalance are considered as early markers of heart disease in Chagas disease (ChD) patients. The objective of the present study was to verify the differences in the occurrence of EIVA and autonomic maneuver indexes between healthy individuals and ChD patients with no apparent cardiac involvement. METHODS A total of 75 ChD patients with no apparent cardiac involvement, aged 44.7 (8.5) years, and 38 healthy individuals, aged 44.0 (9.2) years, were evaluated using echocardiography, symptom-limited treadmill exercise testing and autonomic function tests. RESULTS The occurrence of EIVA was higher in the chagasic group (48%) than in the control group (23.7%) during both the effort and the recovery phases. Frequent ventricular contractions occurred only in the patient group. Additionally, the respiratory sinus arrhythmia index was significantly lower in the chagasic individuals compared with the control group. CONCLUSIONS ChD patients with no apparent cardiac involvement had a higher frequency of EIVA as well as more vagal dysfunction by respiratory sinus arrhythmia. These results suggest that even when asymptomatic, ChD patients possess important arrhythmogenic substrates and subclinical disease.

Prediction of peak oxygen uptake in patients with Chagas heart disease: Value of the Six-minute Walk Test

Chagas disease, an infection caused by the protozoan Trypanosoma cruzi, affects about 10 million people worldwide and another 100 million are at risk of becoming infected [1]. In recent decades, changes in the epidemiological profile of Chagas disease has been observed leading to urbanization and globalization of the infection with increasing prevalence in North America and Europe [2]. Heart disease is the most severe clinical form of the Chagas disease [3] leading to exercise intolerance, especially in advanced stages of the disease. In clinical practice, peak oxygen uptake (VO2peak) is considered the best index of functional capacity (FC), exercise tolerance and cardiorespiratory function [4]. However, maximal exercise testing may not be available in endemic areas for Chagas disease, where usually have poor infrastructure and limited technological resources. An alternative approach is the Six-minute Walk Test (6MWT), a simple, inexpensive and effective tool in assessing FC in cardiac patients [5]. In patients with Chagas heart disease (CHD), the 6MWT was associated with echocardiographic variables [6], demonstrated the effectiveness of exercise-based intervention [7] and correlatedwith VO2peak [8]. However, compared to the VO2peak, the distance walked during the test provides limited information about the functional status of the patient

Heart rate recovery in asymptomatic patients with Chagas disease.

Background Chagas disease patients with right bundle-branch block (RBBB) have diverse clinical presentation and prognosis, depending on left ventricular (LV) function. Autonomic disorder can be an early marker of heart involvement. The heart rate recovery (HRR) after exercise may identify autonomic dysfunction, with impact on therapeutic strategies. This study was designed to assess the HRR after symptom-limited exercise testing in asymptomatic Chagas disease patients with RBBB without ventricular dysfunction compared to patients with indeterminate form of Chagas disease and healthy controls. Methods One hundred and forty-nine subjects divided into 3 groups were included. A control group was comprised of healthy individuals; group 1 included patients in the indeterminate form of Chagas disease; and group 2 included patients with complete RBBB with or without left anterior hemiblock, and normal ventricular systolic function. A symptom-limited exercise test was performed and heart rate (HR) response to exercise was assessed. HRR was defined as the difference between HR at peak exercise and 1 min following test termination. Results There were no differences in heart-rate profile during exercise between healthy individuals and patients in indeterminate form, whereas patients with RBBB had more prevalence of chronotropic incompetence, lower exercise capacity and lower HRR compared with patients in indeterminate form and controls. A delayed decrease in the HR after exercise was found in 17 patients (15%), 9% in indeterminate form and 24% with RBBB, associated with older age, worse functional capacity, impaired chronotropic response, and ventricular arrhythmias during both exercise and recovery. By multivariable analysis, the independent predictors of a delayed decrease in the HRR were age (odds ratio [OR] 1.11; 95% confidence interval [CI] 1.03 to 1.21; p = 0.010) and presence of RBBB (OR 3.97; 95% CI 1.05 to 15.01; p = 0.042). Conclusions A small proportion (15%) of asymptomatic Chagas patients had attenuated HRR after exercise, being more prevalent in patients with RBBB compared with patients in indeterminate form and controls.

Correction for Fares et al., Matrix Metalloproteinases 2 and 9 Are Differentially Expressed in Patients with Indeterminate and Cardiac Clinical Forms of Chagas Disease

Volume 81, no. 10, p. [3600–3608][1], 2013. Page 3605: [Figure 4][2] should appear as shown below. ![FIG 4][3] FIG 4 Evaluation of matrix protein expression in cardiac spheroids. (A) Representative bands of matrix protein expression: collagen type I, fibronectin, laminin, MMP-2, and MMP-9

Relationship between left ventricular ejection fraction and e/e' ratiowith functional capacity in chagas heart disease

Background: Left ventricular dysfunction and functional capacity (FC) are important markers of morbidity and mortality in Chagas heart disease (CHD), however, the relationship between these clinical parameters remains controversial. Objective: To verify the association between FC and systolic and diastolic functions of the left ventricle in CHD patients. Methods: Thirty-five CHD patients (47.11±8.15 years) underwent clinical evaluation, echocardiography and Cardiopulmonary Exercise Testing (CPET) and were classified into two groups: dilated group (dilated cardiomyopathy) and non-dilated group (preserved systolic function). The left ventricular ejection fraction (LVEF), E/e’ ratio and peak oxygen uptake (VO 2peak )were considered. Statistical analysis was carried outwith Pearson or Spearman correlation tests and backward multivariate linear regression analysis was performed to assess the effect of LVEF and E/e’ ratio on VO 2peak . Results: In the overall study population, there was a significant correlation between VO 2peak and LVEF (r=0.536; p=0.001) and a significant negative correlation between VO 2peak and E/e’ ratio (r=-0.399; Relationship between left ventricular ejection fraction and e /e’ ratiowith functional capacity in chagas heart disease Joice Coutinho de Alvarenga1, Pedro Damião Jansen1, Vitória Emilia Gomes Marques1, Henrique Silveira Costa2, Giovane Rodrigo de Sousa2, Aline Cristina de Souza2, Maria do Carmo Pereira Nunes2, Márcia Maria Oliveira Lima3, Manoel Otávio da Costa Rocha4 Relação entre a fração de ejeção do ventrículo esquerdo e razão e/e’ com a capacidade funcional na cardiopatia chagásica DOI: 10.5935/2238-3182.20140118