Matrix metalloproteinases 2 and 9 are differentially expressed in patients with indeterminate and cardiac clinical forms of Chagas disease.

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.

Combined parasitological and molecular-based diagnostic tools improve the detection of Trypanosoma cruzi in single peripheral blood samples from patients with Chagas disease.

INTRODUCTION: In order to detect Trypanosoma cruzi and determine the genetic profiles of the parasite during the chronic phase of Chagas disease (ChD), parasitological and molecular diagnostic methods were used to assess the blood of 91 patients without specific prior treatment. METHODS: Blood samples were collected from 68 patients with cardiac ChD and 23 patients with an indeterminate form of ChD, followed by evaluation using blood culture and polymerase chain reaction. T . cruzi isolates were genotyped using three different genetic markers. RESULTS:: Blood culture was positive in 54.9% of all patients, among which 60.3% had the cardiac form of ChD, and 39.1% the indeterminate form of ChD. There were no significant differences in blood culture positivity among patients with cardiac and indeterminate forms. Additionally, patient age and clinical forms did not influence blood culture results. Polymerase chain reaction (PCR) was positive in 98.9% of patients, although comparisons between blood culture and PCR results showed that the two techniques did not agree. Forty-two T . cruzi stocks were isolated, and TcII was detected in 95.2% of isolates. Additionally, one isolate corresponded to TcIII or TcIV, and another corresponded to TcV or TcVI. CONCLUSIONS: Blood culture and PCR were both effective for identifying T. cruzi using a single blood sample, and their association did not improve parasite detection. However, we were not able to establish an association between the clinical form of ChD and the genetic profile of the parasite.

Health-related quality of life in patients with Chagas disease: a review of the evidence.

Chagas disease (ChD), a neglected tropical disease caused by infection with the parasite Trypanosoma cruzi (T. cruzi), remains a serious public health issue in Latin America and is an emerging disease in several non-endemic countries, where knowledge of the condition and experience with its clinical management are limited. Regionally, the disease is the major cause of disability secondary to tropical diseases in young adults. Health-related quality of life (HRQoL) impairment is common in patients with ChD, especially in those with Chagas dilated cardiomyopathy, the most severe manifestation of the disease, which frequently leads to heart failure. The aim of this review was to conduct a literature search for studies that have evaluated the determining factors of HRQoL in ChD patients. We included cross-sectional, case-control, cohort, and experimental studies, as well as clinical trials that evaluated the HRQoL in ChD patients aged 18 to 60 years and are presenting an explicit description of statistical analysis. Using a combination of keywords based on Descriptors in Health Sciences (DeCS) and Medical Subject Headings (MeSH) for searches in PubMed and the Scientific Electronic Library Online (SciELO), 148 studies were found. After exclusions, 12 studies were selected for analysis. Three main findings were extracted from these studies: 1) cardiac involvement is associated with a worse HRQoL in ChD patients; 2) HRQoL is associated with the patients' functional capacity; and 3) simple and inexpensive therapeutic measures are effective for improving HRQoL in ChD patients. Hence, ChD patients' functional capacity, the effectiveness of non-surgical conservative treatment, and cardiac involvement are important determining factors for the HRQoL in ChD patients.

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.

Prevalence and risk factors of embolic cerebrovascular events associated with Chagas heart disease.

BACKGROUND: Patients with Chagas disease are at increased risk for stroke that may result in major clinical disability and death. Identification of risk factors involved in the genesis of thromboembolic events related to this disease may lead to improved therapeutic decision making and outcomes. OBJECTIVES: This study sought to assess the prevalence of ischemic cerebrovascular events (ICE) among patients with Chagas heart disease and to identify the risk factors associated with cardioembolism in this population. METHODS: This study involved 330 patients, 193 were men (58%), with a mean age of 49 ± 12 years with Chagas disease classified in the chronic cardiac form of the disease. Comprehensive echocardiography was performed to search a substrate for cardioembolic events, especially apical aneurysm and intracavitary thrombus. RESULTS: Most of the patients were classified as New York Heart Association classes I or II (75%) with mean left ventricular (LV) ejection fraction of 39 ± 14%. Sixty-seven patients had a previous ICE with the overall prevalence of 20%. Apical aneurysms were detected in 128 patients (39%), whereas LV mural thrombi were found in 48 patients (15%). In multivariate analysis including the potential predictors of ICE, apical aneurysm (adjusted odds ratio [OR]: 2.19, 95% confidence interval [CI]: 1.11 to 4.34; p = 0.024) and LV thrombus (adjusted OR: 2.43, 95% CI: 1.09 to 5.42; p = 0.030) emerged as important determinants of ICE, after adjusting for anticoagulation therapy. CONCLUSIONS: In a selected population referred to a tertiary center for Chagas disease that included patients with different severities of cardiac involvement, the prevalence of ICE was 20%. The presence of apical aneurysm and intracavitary thrombus were independently associated with ICE, after adjustment for other risk factors for stroke.

Cytokine Signature in Infective Endocarditis.

Infective endocarditis (IE) is a severe disease with high mortality rate. Cytokines participate in its pathogenesis and may contribute to early diagnosis improving the outcome. This study aimed to evaluate the cytokine profile in IE. Serum concentrations of interleukin (IL)-1ß, IL-6, IL-8, IL-10, IL-12 and tumor necrosis factor (TNF)-α were measured by cytometric bead array (CBA) at diagnosis in 81 IE patients, and compared with 34 healthy subjects and 30 patients with non-IE infections, matched to the IE patients by age and gender. Mean age of the IE patients was 47±17 years (range, 15-80 years), and 40 (50%) were male. The IE patients had significantly higher serum concentrations of IL-1ß, IL-6, IL-8, IL-10 and TNF-α as compared to the healthy individuals. The median levels of IL-1ß, TNF-α and IL-12 were higher in the IE than in the non-IE infections group. TNF-α and IL-12 levels were higher in staphylococcal IE than in the non-staphylococcal IE subgroup. There was a higher proportion of both low IL-10 producers and high producers of IL-1ß, TNF-α and IL-12 in the staphylococcal IE than in the non-staphylococcal IE subgroup. This study reinforces a relationship between the expression of proinflammatory cytokines, especially IL-1ß, IL-12 and TNF-α, and the pathogenesis of IE. A lower production of IL-10 and impairment in cytokine network may reflect the severity of IE and may be useful for risk stratification.

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-1ß), 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.

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.

Low levels of vasoactive intestinal peptide are associated with Chagas disease cardiomyopathy.

The interconnection between immune and neuroendocrine systems influences regulation of inflammatory responses. The possible relevance that this integrative response may have during the course of Chagas disease remains poorly characterized. In this context, our study was designed to determine the expression of vasoactive intestinal peptide (VIP), a neuropeptide with anti-inflammatory properties, in blood from the indeterminate and cardiac polarized forms of Chagas disease. Moreover, we determined whether the differential expression of VIP is associated with the development of cardiomyopathy in individuals infected with Trypanosoma cruzi. Finally, we analyzed gene polymorphisms of VIP receptors, VPAC1 and VPAC2, and performed correlation analysis of these polymorphisms with the different clinical forms of Chagas disease. Our results demonstrated that low plasma levels of VIP were associated with the cardiac morbidity in Chagas disease. Accordingly, correlation analysis showed that low plasma levels of VIP were associated with worse cardiac function, as determined by left ventricular ejection fraction and left ventricular diastolic diameter values. Polymorphism analysis showed a significant association between VPAC1 and the indeterminate form of Chagas disease development. Our data indicate that VIP expression and its receptors' polymorphism may be important in determining susceptibility to progression from mild to severe forms of Chagas disease.

Combined parasitological and molecular-based diagnostic tools improve the detection of Trypanosoma cruzi in single peripheral blood samples from patients with Chagas disease

Abstract INTRODUCTION In order to detect Trypanosoma cruzi and determine the genetic profiles of the parasite during the chronic phase of Chagas disease (ChD), parasitological and molecular diagnostic methods were used to assess the blood of 91 patients without specific prior treatment. METHODS Blood samples were collected from 68 patients with cardiac ChD and 23 patients with an indeterminate form of ChD, followed by evaluation using blood culture and polymerase chain reaction. T . cruzi isolates were genotyped using three different genetic markers. RESULTS: Blood culture was positive in 54.9% of all patients, among which 60.3% had the cardiac form of ChD, and 39.1% the indeterminate form of ChD. There were no significant differences in blood culture positivity among patients with cardiac and indeterminate forms. Additionally, patient age and clinical forms did not influence blood culture results. Polymerase chain reaction (PCR) was positive in 98.9% of patients, although comparisons between blood culture and PCR results showed that the two techniques did not agree. Forty-two T . cruzi stocks were isolated, and TcII was detected in 95.2% of isolates. Additionally, one isolate corresponded to TcIII or TcIV, and another corresponded to TcV or TcVI. CONCLUSIONS Blood culture and PCR were both effective for identifying T. cruzi using a single blood sample, and their association did not improve parasite detection. However, we were not able to establish an association between the clinical form of ChD and the genetic profile of the parasite.

Health-related quality of life in patients with Chagas disease: a review of the evidence

Chagas disease (ChD), a neglected tropical disease caused by infection with the parasite Trypanosoma cruzi (T. cruzi), remains a serious public health issue in Latin America and is an emerging disease in several non-endemic countries, where knowledge of the condition and experience with its clinical management are limited. Regionally, the disease is the major cause of disability secondary to tropical diseases in young adults. Health-related quality of life (HRQoL) impairment is common in patients with ChD, especially in those with Chagas dilated cardiomyopathy, the most severe manifestation of the disease, which frequently leads to heart failure. The aim of this review was to conduct a literature search for studies that have evaluated the determining factors of HRQoL in ChD patients. We included cross-sectional, case-control, cohort, and experimental studies, as well as clinical trials that evaluated the HRQoL in ChD patients aged 18 to 60 years and are presenting an explicit description of statistical analysis. Using a combination of keywords based on Descriptors in Health Sciences (DeCS) and Medical Subject Headings (MeSH) for searches in PubMed and the Scientific Electronic Library Online (SciELO), 148 studies were found. After exclusions, 12 studies were selected for analysis. Three main findings were extracted from these studies: 1) cardiac involvement is associated with a worse HRQoL in ChD patients; 2) HRQoL is associated with the patients' functional capacity; and 3) simple and inexpensive therapeutic measures are effective for improving HRQoL in ChD patients. Hence, ChD patients' functional capacity, the effectiveness of non-surgical conservative treatment, and cardiac involvement are important determining factors for the HRQoL in ChD patients.

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. .

Relação entre a fração de ejeção do ventrículo esquerdo e razão e/e' com a capacidade funcional na cardiopatia chagásica / Relationship between left ventricular ejection fraction and e /e' ratiowith functional capacity in chagas heart disease

Introdução: disfunção ventricular e capacidade funcional são importantes marcadores de morbimortalidade na cardiopatia chagásica (CCh). Objetivos: verificar a associação entre a capacidade funcional e funções sistólica e diastólica do ventrículo esquerdo na CCh. Metodologia: foram submetidos 35 pacientes com CCh (47,11±8,15 anos) a avaliação clínica, ecocardiograma e teste de esforço cardiopulmonar (TECP), sendo classificados em dois grupos: dilatado (com cardiomiopatia dilatada) e não dilatado (função sistólica preservada). Foram consideradas as variáveis fração de ejeção do ventrículo esquerdo (FEVE), razão E/e' e o pico do consumo de oxigênio (VO2pico). Na análise estatística foram realizados os testes de Pearson ou Spearman e a análise de regressão linear múltipla avaliou o efeito da FEVE e E/e' no VO2pico. Resultados: na amostra total houve correlação significativa entre o VO2pico e a FEVE (r=0,536, p=0,001) e correlação negativa e significativa entre o VO2pico e razão E/e' (r=-0,399; p=0,022). No grupo dilatado (n=16), correlação significativa foi observada entre o VO2pico com a FEVE (r=0,611, p=0,016) e a razão E/e' (r=-0,601, p=0,018). A análise multivariada das variáveis identificou a FEVE e a razão E/e' como fortes preditores do VO2pico (r=0,850; r2 =0,723).Não houve correlação significativa entre o VO2pico e a FEVE (r=0,393, p=0,107) e a razão E/e' (r=0,102, p=0,687) no grupo não dilatado (n=19). Conclusão: a capacidade funcional avaliada pelo VO2pico relaciona-se à função sistólica e diastólica em pacientes com cardiomiopatia dilatada chagásica.

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 oxygenuptake (VO2peak)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 VO2peak. Results: In the overall study population, there was a significant correlation between VO2peak and LVEF (r=0.536; p=0.001) and a significant negative correlation between VO2peak and E/e' ratio (r=-0.399;p=0.022). In the dilated group (n=16), a significant correlation was also observed between VO2peak and both LVEF(r=0.611; p=0.016) and E/e' ratio (r=-0.601; p=0.018). The multivariate analysis of these variables identified the LVEF and E/e' ratio as strong predictors of VO2peak (r=0.850; r2=0.723). In contrast, in the non-dilated group (n=19), there was no significant correlation between VO- 2peak and LVEF (r=0.393; p=0.107) and E/e' ratio (r=0.102; p=0.687). Conclusion: Functional capacity assessed by VO2peak was related to systolic and diastolic function in CHD patients with dilated cardiomyopathy.