Biomarkers in Trypanosoma cruzi-infected and uninfected individuals with varying severity of cardiomyopathy in Santa Cruz, Bolivia

A Trypanosoma cruzi Trans-Sialidase Peptide Demonstrates High Serological Prevalence Among Infected Populations Across Endemic Regions of Latin America

Infection by Trypanosoma cruzi, the agent of Chagas disease, can irreparably damage the cardiac and gastrointestinal systems during decades of parasite persistence and related inflammation in these tissues. Diagnosis of chronic disease requires confirmation by multiple serological assays due to the imperfect performance of existing clinical tests. Current serology tests utilize antigens discovered over three decades ago with small specimen sets predominantly from South America, and lower test performance has been observed in patients who acquired T. cruzi infection in Central America and Mexico. Here, we attempt to address this gap by evaluating antibody responses against the entire T. cruzi proteome with phage display immunoprecipitation sequencing comprised of 228,127 47-amino acid peptides. We utilized diverse specimen sets from Mexico, Central America and South America, as well as different stages of cardiac disease severity, from 185 cases and 143 controls. We identified over 1,300 antigenic T. cruzi peptides derived from 961 proteins between specimen sets. A total of 67 peptides were reactive in 70% of samples across all regions, and 3 peptide epitopes were enriched in ≥90% of seropositive samples. Of these three, only one antigen, belonging to the trans-sialidase family, has not previously been described as a diagnostic target. Orthogonal validation of this peptide demonstrated increased antibody reactivity for infections originating from Central America. Overall, this study provides proteome-wide identification of seroreactive T. cruzi peptides across a large cohort spanning multiple endemic areas and identified a novel trans-sialidase peptide antigen (TS-2.23) with significant potential for translation into diagnostic serological assays.

Small molecule biomarkers predictive of Chagas disease progression

Chagas disease (CD) is a neglected tropical disease caused by the parasitic protozoan Trypanosoma cruzi. However, only 20% to 30% of infected individuals will progress to severe symptomatic cardiac manifestations. Current treatments are benznidazole and nifurtimox, which are poorly tolerated regimens. Developing a biomarker to determine the likelihood of patient progression would be helpful for doctors to optimize patient treatment strategies. Such a biomarker would also benefit drug discovery efforts and clinical trials. In this study, we combined untargeted and targeted metabolomics to compare serum samples from T. cruzi-infected individuals who progressed to severe cardiac disease, versus infected individuals who remained at the same disease stage (non-progressors). We identified four unannotated biomarker candidates, which were validated in an independent cohort using both untargeted and targeted analysis techniques. Overall, our findings demonstrate that serum small molecules can predict CD progression, offering potential for clinical monitoring.

Persistent Biofluid Small-Molecule Alterations Induced by Trypanosoma cruzi Infection Are Not Restored by Parasite Elimination

Chagas disease (CD), caused by Trypanosoma cruzi (T. cruzi) protozoa, is a complicated parasitic illness with inadequate medical measures for diagnosing infection and monitoring treatment success. To address this gap, we analyzed changes in the metabolome of T. cruzi-infected mice via liquid chromatography tandem mass spectrometry of clinically accessible biofluids: saliva, urine, and plasma. Urine was the most indicative of infection status across mouse and parasite genotypes. Metabolites perturbed by infection in urine include kynurenate, acylcarnitines, and threonylcarbamoyladenosine. Based on these results, we sought to implement urine as a tool for the assessment of CD treatment success. Strikingly, it was found that mice with parasite clearance following benznidazole antiparasitic treatment had an overall urine metabolome comparable to that of mice that failed to clear parasites. These results provide a complementary hypothesis to explain clinical trial data in which benznidazole treatment did not improve patient outcomes in late-stage disease, even in patients with successful parasite clearance. Overall, this study provides insights into new small-molecule-based CD diagnostic methods and a new approach to assess functional responses to treatment.

Persistent biofluid small molecule alterations induced by Trypanosoma cruzi infection are not restored by antiparasitic treatment

Chagas Disease (CD), caused by Trypanosoma cruzi (T. cruzi) protozoa, is a complicated parasitic illness with inadequate medical measures for diagnosing infection and monitoring treatment success. To address this gap, we analyzed changes in the metabolome of T. cruzi-infected mice via liquid chromatography tandem mass spectrometry analysis of clinically-accessible biofluids: saliva, urine, and plasma. Urine was the most indicative of infection status, across mouse and parasite genotypes. Metabolites perturbed by infection in the urine include kynurenate, acylcarnitines, and threonylcarbamoyladenosine. Based on these results, we sought to implement urine as a tool for assessment of CD treatment success. Strikingly, it was found that mice with parasite clearance following benznidazole antiparasitic treatment had comparable overall urine metabolome to mice that failed to clear parasites. These results match with clinical trial data in which benznidazole treatment did not improve patient outcomes in late-stage disease. Overall, this study provides insights into new small molecule-based CD diagnostic methods and a new approach to assess functional treatment response.

Risk Factors for Progression to Chronic Chagas Cardiomyopathy: A Systematic Review and Meta-Analysis

Approximately one-third of people with chronic Trypanosoma cruzi infection develop Chagas cardiomyopathy, which carries a poor prognosis. Accurate prediction of which individuals will go on to develop Chagas cardiomyopathy remains elusive. We performed a systematic review of literature comparing characteristics of individuals with chronic Chagas disease with or without evidence of cardiomyopathy. Studies were not excluded on the basis of language or publication date. Our review yielded a total of 311 relevant publications. We further examined the subset of 170 studies with data regarding individual age, sex, or parasite load. A meta-analysis of 106 eligible studies indicated that male sex was associated with having Chagas cardiomyopathy (Hedge's g: 1.56, 95% CI: 1.07-2.04), and a meta-analysis of 91 eligible studies indicated that older age was associated with having Chagas cardiomyopathy (Hedge's g: 0.66, 95% CI: 0.41-0.91). A meta-analysis of four eligible studies did not find an association between parasite load and disease state. This study provides the first systematic review to assess whether age, sex, and parasite load are associated with Chagas cardiomyopathy. Our findings suggest that older and male patients with Chagas disease are more likely to have cardiomyopathy, although we are unable to identify causal relationships due to the high heterogeneity and predominantly retrospective study designs in the current literature. Prospective, multidecade studies are needed to better characterize the clinical course of Chagas disease and identify risk factors for progression to Chagas cardiomyopathy.

Cytokine Networks as Targets for Preventing and Controlling Chagas Heart Disease

Chagas disease, a neglected disease caused by the protozoan Trypanosoma cruzi, is endemic in 21 Latin American countries, affecting 6-8 million people. Increasing numbers of Chagas disease cases have also been reported in non-endemic countries due to migration, contamination via blood transfusions or organ transplantation, characterizing Chagas as an emerging disease in such regions. While most individuals in the chronic phase of Chagas disease remain in an asymptomatic clinical form named indeterminate, approximately 30% of the patients develop a cardiomyopathy that is amongst the deadliest cardiopathies known. The clinical distinctions between the indeterminate and the cardiac clinical forms are associated with different immune responses mediated by innate and adaptive cells. In this review, we present a collection of studies focusing on the human disease, discussing several aspects that demonstrate the association between chemokines, cytokines, and cytotoxic molecules with the distinct clinical outcomes of human infection with Trypanosoma cruzi. In addition, we discuss the role of gene polymorphisms in the transcriptional control of these immunoregulatory molecules. Finally, we discuss the potential application of cytokine expression and gene polymorphisms as markers of susceptibility to developing the severe form of Chagas disease, and as targets for disease control.

Call for Consensus in the Evaluation of Circulating Matrix Metalloproteinases in Chagas Disease

Infection with the Trypanosoma cruzi parasite is endemic in parts of America. Approximately 30% of people infected develop Chagas cardiomyopathy, the most common cause of heart failure in these regions. No suitable biomarker that reflects the evolution of the disease has been widely accepted as of yet. There is substantial evidence, however, of a strong inflammatory reaction following infection with T. cruzi that could activate matrix metalloproteinases (MMPs). Emerging research suggests the involvement of MMPs in Chagas cardiomyopathy and there is a growing interest in measuring the blood levels of MMPs as diagnostic and/or prognostic indicators of heart damage in Chagas patients. This perspective discusses the lack of consensus on the best method for MMP evaluation. Some studies are based on MMP concentrations and activities in serum whereas others use plasma. We believe that these different methods of evaluation have led to incongruent and poorly comparable data on the blood levels of MMPs in Chagas patients. A standard for the preparation of blood samples needs to be adopted for the study of MMPs as markers of Chagas cardiomyopathy to ensure better comparability of research results.

Prognosis of chronic Chagas heart disease and other pending clinical challenges

In this chapter, the main prognostic markers of Chagas heart disease are addressed, with an emphasis on the most recent findings and questions, establishing the basis for a broad discussion of recommendations and new approaches to managing Chagas cardiopathy. The main biological and genetic markers and the contribution of the electrocardiogram, echocardiogram and cardiac magnetic resonance are presented. We also discuss the most recent therapeutic proposals for heart failure, thromboembolism and arrhythmias, as well as current experience in heart transplantation in patients suffering from severe Chagas cardiomyopathy. The clinical and epidemiological challenges introduced by acute Chagas disease due to oral contamination are discussed. In addition, we highlight the importance of ageing and comorbidities in influencing the outcome of chronic Chagas heart disease. Finally, we discuss the importance of public policies, the vital role of funding agencies, universities, the scientific community and health professionals, and the application of new technologies in finding solutions for better management of Chagas heart disease.

Cardiovascular Biomarkers and Diastolic Dysfunction in Patients With Chronic Chagas Cardiomyopathy

Background: Chronic Chagas Cardiomyopathy is a unique form of cardiomyopathy, with a significantly higher mortality risk than other heart failure etiologies. Diastolic dysfunction (DD) plays an important role in the prognosis of CCM; however, the value of serum biomarkers in identifying and stratifying DD has been poorly studied in this context. We aimed to analyze the correlation of six biochemical markers with diastolic function echocardiographic markers and DD diagnosis in patients with CCM.

Methods: Cross-sectional study of 100 adults with different stages of CCM. Serum concentrations of amino-terminal pro-B type natriuretic peptide (NT-proBNP), galectin-3 (Gal-3), neutrophil gelatinase-associated lipocalin (NGAL), high-sensitivity troponin T (hs-cTnT), soluble (sST2), and cystatin-C (Cys-c) were measured. Tissue Doppler imaging was used to measure echocardiographic parameters indicating DD. Multivariate logistic regression models adjusted by age, sex, BMI, and NYHA classification were used to evaluate the association between the biomarkers and DD.

Results: From the total patients included (55% male with a median age of 62 years), 38% had a preserved LVEF, but only 14% had a normal global longitudinal strain. Moreover, 64% had a diagnosis of diastolic dysfunction, with most of the patients showing a restrictive pattern (n = 28). The median levels of all biomarkers (except for sST2) were significantly higher in the group of patients with DD. Higher levels of natural log-transformed NTproBNP (per 1-unit increase, OR = 3.41, p < 0.001), Hs-cTnT (per 1-unit increase, OR = 3.24, p = 0.001), NGAL (per 1-unit increase, OR = 5.24, p =0.003), and Cys-C (per 1-unit increase, OR = 22.26, p = 0.008) were associated with increased odds of having diastolic dysfunction in the multivariate analyses. Finally, NT-proBNP had the highest AUC value (88.54) for discriminating DD presence.

Conclusion: Cardiovascular biomarkers represent valuable tools for diastolic dysfunction assessment in the context of CCM. Additional studies focusing mainly on patients with HFpEF are required to validate the performance of these cardiovascular biomarkers in CCM, allowing for an optimal assessment of this unique population.

Circulating DHEA-S levels and major cardiovascular outcomes in chronic Chagas cardiomyopathy: A prospective cohort study

OBJECTIVE

To analyze the association of circulating dehydroepiandrosterone sulfate (DHEA-S) levels with cardiovascular outcomes in patients with chronic Chagas cardiomyopathy (CCM) diagnosis.

BACKGROUND

DHEA-S is among the main endogenous steroid hormones. Some studies have suggested a relevant role of this hormone in infections and the setting of CCM. Nevertheless, no study has evaluated the prognostic role of DHEA-S in CCM patients.

METHODS

Prospective cohort study. Patients with CCM and reduced ejection fraction were included. We explored the association of DHEA-S levels with NT-proBNP levels and echocardiographic variables using linear regression models. Next, by using Cox Proportional Hazard models, we examined whether levels of DHEA-S could predict a composite outcome (CO) including all-cause mortality, cardiac transplantation, and implantation of a left ventricular assist device (LVAD).

RESULTS

Seventy-four patients were included (59% males, median age: 64 years). After adjustment for confounding factors, high DHEA-S levels were associated with better LVEF, lower left atrium volume, end-systolic volume of the left ventricle and lower NT-proBNP levels. 43% of patients experienced the CO during a median follow-up of 40 months. Increased levels of DHEA-S were associated with a lower risk of developing the CO (HR 0.43; 95%CI 0.21-0.86). Finally, adding DHEA-S to the multivariate model did not improve the prediction of the CO, but substituting NT-proBNP in the model with DHEA-S showed similar performance.

CONCLUSIONS

In patients with CCM, higher DHEA-S levels were associated with lower mortality, heart transplantation, and LVAD implantation. Further larger studies are required to confirm our results and assess causality.

Cardiovascular biomarkers as predictors of adverse outcomes in chronic Chagas cardiomyopathy

BACKGROUND

Chronic Chagas Cardiomyopathy (CCM) is a unique form of cardiomyopathy compared to other etiologies of heart failure. In CCM, risk prediction based on biomarkers has not been well-studied. We assessed the prognostic value of a biomarker panel to predict a composite outcome (CO), including the need for heart transplantation, use of left ventricular assist devices, and mortality.

METHODS

Prospective cohort study of 100 adults with different stages of CCM. Serum concentrations of amino-terminal pro-B type natriuretic peptide (NT-proBNP), galectin-3 (Gal-3), neutrophil gelatinase-associated lipocalin (NGAL), high sensitivity troponin T (hs-cTnT), soluble (sST2), and cystatin-C (Cys-c) were measured. Survival analyses were performed using Cox proportional hazard models.

RESULTS

During a median follow-up of 52 months, the mortality rate was 20%, while the CO was observed in 25% of the patients. Four biomarkers (NT-proBNP, hs-cTnT, sST2, and Cys-C) were associated with the CO; concentrations of NT-proBNP and hs-cTnT were associated with the highest AUC (85.1 and 85.8, respectively). Combining these two biomarkers above their selected cut-off values significantly increased risk for the CO (HR 3.18; 95%CI 1.31-7.79). No events were reported in the patients in whom the two biomarkers were under the cut-off values, and when both levels were above cut-off values, the CO was observed in 60.71%.

CONCLUSION

The combination of NT-proBNP and hs-TnT above their selected cut-off values is associated with a 3-fold increase in the risk of the composite outcome among CCM patients. The use of cardiac biomarkers may improve prognostic evaluation of patients with CCM.

Chagas Cardiomyopathy: From Romaña Sign to Heart Failure and Sudden Cardiac Death

Despite nearly a century of research and accounting for the highest disease burden of any parasitic disease in the Western Hemisphere, Chagas disease (CD) is still a challenging diagnosis, primarily due to its poor recognition outside of Latin America. Although initially considered endemic to Central and South America, globalization, urbanization, and increased migration have spread the disease worldwide in the last few years, making it a significant public health threat. The international medical community's apparent lack of interest in this disease that was previously thought to be geographically restricted has delayed research on the complex host-parasite relationship that determines myocardial involvement and its differential behavior from other forms of cardiomyopathy, particularly regarding treatment strategies. Multiple cellular and molecular mechanisms that contribute to degenerative, inflammatory, and fibrotic myocardial responses have been identified and warrant further research to expand the therapeutic arsenal and impact the high burden attributed to CD. Altogether, cardiac dysautonomia, microvascular disturbances, parasite-mediated myocardial damage, and chronic immune-mediated injury are responsible for the disease's clinical manifestations, ranging from asymptomatic disease to severe cardiac and gastrointestinal involvement. It is crucial for healthcare workers to better understand CD transmission and disease dynamics, including its behavior on both its acute and chronic phases, to make adequate and evidence-based decisions regarding the disease. This review aims to summarize the most recent information on the epidemiology, pathogenesis, clinical presentation, diagnosis, screening, and treatment of CD, emphasizing on Chagasic cardiomyopathy's (Ch-CMP) clinical presentation and pathobiological mechanisms leading to sudden cardiac death.

Biomarkers assessment in patients with Chagas disease and systemic arterial hypertension

Chagas disease (ChD) and systemic arterial hypertension (SAH) are two severe comorbidities that lead to mortality and a reduction in people's quality of life, with an impact on public health. The aim of this study was to quantify the biomarkers of cardiac injury in patients with ChD and SAH. Eighty patients were divided into four groups: 20 hypertensive patients, 20 ChD-hypertensive patients, 20 ChD patients, and 20 normotensive volunteers; all of them came from outpatient's public health services. Among the evaluated markers for cardiac lesions (creatine kinase, creatine kinase-MB isoform, myoglobin, high-sensitive cardiac troponin T[hs-cTnT], B-type natriuretic peptide [BNP], and C-reactive protein), hs-cTnT and BNP were the most appropriate. Importantly, our results showed that the cut off point for hs-cTnT could be < 0.007 ng/mL, which could lead to the early detection of myocardial lesions. The BNP and hs-cTnT levels were high only in the ChD and ChD-hypertensive patient groups, suggesting that Chagas' disease may play an important role in the increase of these biomarkers. ChD patients, hypertensive or not, with cardiac or cardiodigestive involvement presented significantly higher values of hs-cTnT (p < 0.001) and BNP (p = 0.001) than ChD patients with indeterminate and digestive forms, which strengthens the validation of these markers for the follow-up of clinical cardiac form of ChD. This study suggests that the BNP and hs-cTnT can be used as possible indirect biomarkers of cardiac damage. In addition, the reference values of these biomarkers in Chagas and hypertensive cardiomyopathies should be better understood with further studies.

State-of-the-art in host-derived biomarkers of Chagas disease prognosis and early evaluation of anti-Trypanosoma cruzi treatment response

Chagas disease is caused by infection with the parasite Trypanosoma cruzi, which might lead to a chronic disease state and drive to irreversible damage to the heart and/or digestive tract tissues. Endemic in 21 countries in the Americas, it is the neglected disease with a highest burden in the region. Current estimates point at ~6 million people infected, of which ~30% will progress onto the symptomatic tissue disruptive stage. There is no vaccine but there are two anti-parasitic drugs available: benznidazole and nifurtimox. However, their efficacy is variable at the chronic symptomatic stage and both have frequent adverse effects. Since there are no prognosis markers, drugs should be administered to all T. cruzi-infected individuals in the indeterminate and early symptomatic stages. Nowadays, there are no tests-of-cure either, which greatly undermines patients follow-up and the search of safer and more efficacious drugs. Therefore, the identification and validation of biomarkers of disease progression and/or treatment response on which to develop tests of prognosis and/or cure is a major research priority. Both parasite- and host-derived markers have been investigated. In the present manuscript we present an updated outlook of the latter.

Echocardiographic parameters, speckle tracking, and brain natriuretic peptide levels as indicators of progression of indeterminate stage to Chagas cardiomyopathy

BACKGROUND

Chronic Chagas cardiomyopathy (CCM) is characterized by a unique type of cardiac involvement. Few studies have characterized echocardiographic (Echo) transitions from the indeterminate Chagas disease (ChD) form to CCM. The objective of this study was to identify the best cutoffs in multiple Echo parameters, speckle tracking, and N-terminal pro B-type natriuretic peptide (NT-proBNP) to distinguish patients without CCM (stage A) vs patients with myocardial involvement (stages B, C, or D).

METHODS

Cross-sectional study conducted in 273 consecutive patients with different CCM stages. Echo parameters, NT-proBNP, and other clinical variables were measured. Logistic regression models (dichotomized in stage A versus B, C, and D) adjusted for age, sex, body mass index, and NT-proBNP were performed.

RESULTS

Left ventricular global longitudinal strain (LV-GLS), mitral flow E velocity, LV mass index, and NT-proBNP identified early changes that differentiated stages A vs B, C, and D. The LV-GLS with a cutoff -20.5% showed the highest performance (AUC 92.99%; accuracy 84.56% and negative predictive value (NPV) 88.82%), which improved when it was additionally adjusted by NT-proBNP with a cutoff -20.0% (AUC 94.30%; accuracy 88.42% and NPV 93.55%).

CONCLUSIONS

Our findings suggest that Echo parameters and NT-proBNP may be used as diagnostic variables in detecting the onset of myocardial alterations in patients with the indeterminate stage of ChD. LV-GLS was the more accurate measurement regarding stage A differentiation from the stages B, C, and D. Prospective longitudinal studies are needed to validate these findings.

Diet Alters Serum Metabolomic Profiling in the Mouse Model of Chronic Chagas Cardiomyopathy

Chagas disease is caused by Trypanosoma cruzi which is endemic in Latin America. T. cruzi infection results in a latent infection with approximately a third of latently infected patients developing chronic Chagas cardiomyopathy (CCM). CCM is a common cause of cardiomyopathy in endemic regions and has a poor prognosis compared to other cardiomyopathies. The factors responsible for the transition from the asymptomatic indeterminate latent stage of infection to CCM are poorly understood. Our previous studies demonstrated that lipid metabolism and diet are important determinants of disease progression. In the present study, we analyzed various serum metabolomic biomarkers such as acylcarnitines, amino acids, biogenic amines, glycerophospholipids, and sphingolipids in murine models of CCM, where the mice specifically develop either left or right ventricular cardiomyopathy based on the diets fed during the indeterminate stage in a murine model of Chagas disease. Our data provide new insights into the metabolic changes that may predispose patients to CCM and biomarkers that may help predict the risk of developing cardiomyopathy from T. cruzi infection. Author Summary. Chronic Chagas cardiomyopathy (CCM) is a parasitic disease prevalent in Latin America. Currently, no effective drugs or vaccines are available to prevent or cure CCM. The factors involved in the disease severity and progression are poorly understood to design new therapeutic interventions. In order to rapidly identify Chagas patients with a higher risk to develop CCM, a new set of biomarkers specific to Chagas disease is needed. We performed serum metabolomic analyses in chronic T. cruzi-infected mice fed on different diets and identified cardiac ventricular-specific metabolite biomarkers that could define CCM severity. In this paper, we present the results of serum metabolomic analyses and discuss its correlations to the diet-induced metabolic regulations in the pathogenesis of CCM in a murine model of Chagas disease.

Severity of Chagasic Cardiomyopathy Is Associated With Response to a Novel Rapid Diagnostic Test for Trypanosoma cruzi TcII/V/VI

Background

Trypanosoma cruzi causes Chagas disease in the Americas. The outcome of infection ranges from lifelong asymptomatic status to severe disease. Relationship between T. cruzi lineage (TcI-TcVI) infection history and prognosis is not understood. We previously described peptide-based lineage-specific enzyme-linked immunosorbent assay (ELISA) with trypomastigote small surface antigen (TSSA).

Methods

A novel rapid diagnostic test (RDT; Chagas Sero K-SeT) that incorporates a peptide that corresponds to the TSSA II/V/VI common epitope was developed and validated by comparison with ELISA. Patients from Bolivia and Peru, including individuals with varying cardiac pathology, and matched mothers and neonates, were then tested using Chagas Sero K-SeT.

Results

Chagas Sero K-SeT and ELISA results, with a Bolivian subset of cardiac patients, mothers, and neonates, were in accord. In adult chronic infections (n = 121), comparison of severity class A (no evidence of Chagas cardiomyopathy) with class B (electrocardiogram suggestive of Chagas cardiomyopathy) and class C/D (decreased left ventricular ejection fraction; moderate/severe Chagas cardiomyopathy) revealed a statistically significant increase in Chagas Sero K-SeT reactivity with increasing severity (χ2 for trend, 7.39; P = .007). In Peru, Chagas Sero K-SeT detected the sporadic TcII/V/VI infections.

Conclusions

We developed a low cost RDT that can replace ELISA for identification of TSSA II/V/VI immunoglobulin G. Most importantly, we show that response to this RDT is associated with severity of Chagas cardiomyopathy and thus may have prognostic value. Repeated challenge with T. cruzi infection may both exacerbate disease progression and boost the immune response to the TSSApep-II/V/VI epitope.

MMP-2 and MMP-9 plasma levels are potential biomarkers for indeterminate and cardiac clinical forms progression in chronic Chagas disease

One of the major challenges in chronic Chagas disease is to understand the mechanisms that predict the clinical evolution from asymptomatic to severe cardiac clinical forms. Our cohort consisted of twenty-eight Chagas disease patients followed for twenty years. Plasma levels of MMP-2 and MMP-9 gelatinases and TIMPs were evaluated by multiplexed immunoassay at two points in time with an average interval of six years. MMP-2 plasma levels, but not MMP-9, increased in cardiac patients over time. TIMP-1 levels diminished in cardiac patients, while TIMP-3 dropped in asymptomatic patients in the course of the evaluated interval. An inversion of time lines was observed relative to the clinical asymptomatic and cardiac forms for MMP-2. Receiver Operating Characteristic (ROC) curve analysis identified MMP-2 as a biomarker to distinguish asymptomatic from cardiac clinical forms, while MMP-9 is a biomarker that segregates infected from non-infected patients. We have pointed out that MMP-2 and MMP-9 together can predict clinical evolution in Chagas disease. MMP-2 was suggested as a biomarker for fibrosis replacement in early remodeling and a sensitive predictor for initial changes in asymptomatic patients that may evolve into the cardiac clinical form. MMP-9 seems to be a biomarker for late fibrosis and severe cardiac remodeling in cardiac patients.

Host-Derived Molecules as Novel Chagas Disease Biomarkers: Hypercoagulability Markers in Plasma

The most severe clinical symptomatology of Chagas disease affects ~30% of those chronically infected with the Trypanosoma cruzi parasite. The pathogenic mechanisms that lead to life-threatening heart and gut tissue disruptions occur "silently" for a longtime in a majority of cases. As a result, despite there are several serological and molecular methods available to diagnose the infection in its acute and chronic stages, diagnosis is often achieved only after the onset of clinical symptoms in the chronic phase of the disease. Furthermore, although there are two drugs to treat it, the assessment of their performance is impractical with current parasite-derived diagnostics, and therapeutic efficacy cannot be acknowledged in a timely manner.In this chapter we present two procedures to measure host-derived molecules as surrogates of therapeutic response against chronic T. cruzi infection. Their outputs relate to the generation and activity of thrombin, a major component of the blood coagulation cascade. This is due to the fact that a hypercoagulability state has been described to occur in chronic Chagas disease patients and revert after treatment with benznidazole.

Effects of low-dose energy spectrum scanning combined with adaptive statistical iterative reconstruction on the quality of imaging in Budd-Chiari syndrome

OBJECTIVE

To assess the quality and diagnostic accuracy of monochromatic images combined with adaptive statistical iterative reconstruction (ASIR) performed via spectral computed tomography (CT) in patients with Budd-Chiari syndrome (BCS).

METHODS

Sixty-two patients with BCS underwent pectral CT with upper abdominal two-phase contrast-enhanced scanning to generate a 60keV monochromatic energy level combined with ASIR (ranging from 0% -100%) during the portal venous phase (PVP) and the hepatic venous phase (HVP). One-way ANOVA was used to compare vessel-to-liver contrast-to-noise ratio (CNR) for the portal vein (PV), hepatic vein (HV), and inferior vena cava (IVC). Subjective evaluations of the images in the three groups were conducted by image quality assessors and compared via Kruskal-Wallis H test.

RESULTS

The CNR values of the PV trunk, HV, IVC, liver parenchyma and pancreas were within ASIR (ranging from 0% - 100%) weight, and the difference were statistically significant (p <0.05). The highest overall image score was distributed at 50% ASIR weight value. Higher CNR values of HV, hepatic parenchyma and pancreas were obtained in the IVC type than in mixed and HV types (respective p values = 0.035, 0.019 and 0.042). Higher CNR values of the IVC were obtained in the HV type than in mixed and IVC types (p = 0.032). The CNR value of the IVC in the mixed type was less than that of the HV type (p = 0.028). The CNR values of the HV and liver parenchyma in mixed type were lower than those of the IVC type (p = 0.016 and 0.038, respectively). The CNR value of pancreas in IVC type was higher than that of the HV type (p = 0.037). The diagnostic value of CNR in patients with the IVC type was higher than that in patients with mixed and HV type, while the diagnostic value of CNR was found to be the lowest for the HV type (p = 0.043).

CONCLUSION

A monochromatic energy level of 60 keV with 50% ASIR can significantly improve image quality in cases of BCS.

Chagas Cardiomyopathy: An Update of Current Clinical Knowledge and Management: A Scientific Statement From the American Heart Association

Background:

Chagas disease, resulting from the protozoan Trypanosoma cruzi , is an important cause of heart failure, stroke, arrhythmia, and sudden death. Traditionally regarded as a tropical disease found only in Central America and South America, Chagas disease now affects at least 300 000 residents of the United States and is growing in prevalence in other traditionally nonendemic areas. Healthcare providers and health systems outside of Latin America need to be equipped to recognize, diagnose, and treat Chagas disease and to prevent further disease transmission.

Methods and Results:

The American Heart Association and the Inter-American Society of Cardiology commissioned this statement to increase global awareness among providers who may encounter patients with Chagas disease outside of traditionally endemic environments. In this document, we summarize the most updated information on diagnosis, screening, and treatment of T cruzi infection, focusing primarily on its cardiovascular aspects. This document also provides quick reference tables, highlighting salient considerations for a patient with suspected or confirmed Chagas disease.

Conclusions:

This statement provides a broad summary of current knowledge and practice in the diagnosis and management of Chagas cardiomyopathy. It is our intent that this document will serve to increase the recognition of Chagas cardiomyopathy in low-prevalence areas and to improve care for patients with Chagas heart disease around the world.

Chagas disease

Chagas disease is an anthropozoonosis from the American continent that has spread from its original boundaries through migration. It is caused by the protozoan Trypanosoma cruzi, which was identified in the first decade of the 20th century. Once acute infection resolves, patients can develop chronic disease, which in up to 30-40% of cases is characterised by cardiomyopathy, arrhythmias, megaviscera, and, more rarely, polyneuropathy and stroke. Even after more than a century, many challenges remain unresolved, since epidemiological control and diagnostic, therapeutic, and prognostic methods must be improved. In particular, the efficacy and tolerability profile of therapeutic agents is far from ideal. Furthermore, the population affected is older and more complex (eg, immunosuppressed patients and patients with cancer). Nevertheless, in recent years, our knowledge of Chagas disease has expanded, and the international networking needed to change the course of this deadly disease during the 21st century has begun.

Association of caspase-1 polymorphisms with Chagas cardiomyopathy among individuals in Santa Cruz, Bolivia

INTRODUCTION:

Trypanosoma cruzi (Tc) infection is usually acquired in childhood in endemic areas, leading to Chagas disease, which progresses to Chagas cardiomyopathy in 20-30% of infected individuals over decades. The pathogenesis of Chagas cardiomyopathy involves the host inflammatory response to T. cruzi, in which upstream caspase-1 activation prompts the cascade of inflammatory chemokines/cytokines, cardiac remodeling, and myocardial dysfunction. The aim of the present study was to examine the association of two caspase-1 single nucleotide polymorphisms (SNPs) with cardiomyopathy.

METHODS:

We recruited infected (Tc+, n = 149) and uninfected (Tc-, n = 87) participants in a hospital in Santa Cruz, Bolivia. Cardiac status was classified (I, II, III, IV) based on Chagas cardiomyopathy-associated electrocardiogram findings and ejection fractions on echocardiogram. Genotypes were determined using Taqman probes via reverse transcription-polymerase chain reaction of peripheral blood DNA. Genotype frequencies were analyzed according to three inheritance patterns (dominant, recessive, additive) using logistic regression adjusted for age and sex.

RESULTS:

The AA allele for the caspase-1 SNP rs501192 was more frequent in Tc+ cardiomyopathy (classes II, III, IV) patients compared to those with a normal cardiac status (class I) [odds ratio (OR) = -2.18, p = 0.117]. This trend approached statistical significant considering only Tc+ patients in class I and II (OR = -2.64, p = 0.064).

CONCLUSIONS:

Caspase-1 polymorphisms may play a role in Chagas cardiomyopathy development and could serve as markers to identify individuals at higher risk for priority treatment.

Chronic Chagas Heart Disease Management: From Etiology to Cardiomyopathy Treatment

Trypanosoma cruzi (T. cruzi) infection is endemic in Latin America and is becoming a worldwide health burden. It may lead to heterogeneous phenotypes. Early diagnosis of T. cruzi infection is crucial. Several biomarkers have been reported in Chagas heart disease (ChHD), but most are nonspecific for T. cruzi infection. Prognosis of ChHD patients is worse compared with other etiologies, with sudden cardiac death as an important mode of death. Most ChHD patients display diffuse myocarditis with fibrosis and hypertrophy. The remodeling process seems to be associated with etiopathogenic mechanisms and neurohormonal activation. Pharmacological treatment and antiarrhythmic therapy for ChHD is mostly based on results for other etiologies. Heart transplantation is an established, valuable therapeutic option in refractory ChHD. Implantable cardioverter-defibrillators are indicated for prevention of secondary sudden cardiac death. Specific etiological treatments should be revisited and reserved for select patients. Understanding and management of ChHD need improvement, including development of randomized trials.

Endogenous osteopontin induces myocardial CCL5 and MMP-2 activation that contributes to inflammation and cardiac remodeling in a mouse model of chronic Chagas heart disease

Cardiac dysfunction with progressive inflammation and fibrosis is a hallmark of Chagas disease caused by persistent Trypanosoma cruzi infection. Osteopontin (OPN) is a pro-inflammatory cytokine that orchestrates mechanisms controlling cell recruitment and cardiac architecture. Our main goal was to study the role of endogenous OPN as a modulator of myocardial CCL5 chemokine and MMP-2 metalloproteinase, and its pathological impact in a murine model of Chagas heart disease. Wild-type (WT) and OPN-deficient (spp1 -/-) mice were parasite-infected (Brazil strain) for 100days. Both groups developed chronic myocarditis with similar parasite burden and survival rates. However, spp1 -/- infection showed lower heart-to-body ratio (P<0.01) as well as reduced inflammatory pathology (P<0.05), CCL5 expression (P<0.05), myocyte size (P<0.05) and fibrosis (P<0.01) in cardiac tissues. Intense OPN labeling was observed in inflammatory cells recruited to infected heart (P<0.05). Plasma concentration of MMP-2 was higher (P<0.05) in infected WT than in spp1 -/- mice. Coincidently, specific immunostaining revealed increased gelatinase expression (P<0.01) and activity (P<0.05) in the inflamed hearts from T. cruzi WT mice, but not in their spp1 -/- littermates. CCL5 and MMP-2 induction occurred preferentially (P<0.01) in WT heart-invading CD8⁺ T cells and was mediated via phospho-JNK MAPK signaling. Heart levels of OPN, CCL5 and MMP-2 correlated (P<0.01) with collagen accumulation in the infected WT group only. Endogenous OPN emerges as a key player in the pathogenesis of chronic Chagas heart disease, through the upregulation of myocardial CCL5/MMP-2 expression and activities resulting in pro-inflammatory and pro-hypertrophic events, cardiac remodeling and interstitial fibrosis.

Synergic and antagonistic relationship between MMP-2 and MMP-9 with fibrosis and inflammation in Chagas' cardiomyopathy

Cardiomyopathy is the most important clinical manifestation in the chronic phase of Chagas' disease because of its frequency, severity and impact on morbidity and mortality. The extracellular matrix degradation during cardiac remodeling in Trypanosoma cruzi infection is driven by matrix metalloproteinases (MMPs), primarily the MMP-2 and MMP-9 gelatinases. MMPs also regulate some molecules related to inflammation, such as growth factors, cytokines and chemokines. The involvement of MMP-2 and MMP-9 is not yet fully understood in Chagas' disease. It has been proposed that the gelatinases may have opposite effect on inflammation/regulation and cardiac remodeling. MMP-2 would participate in regulation, offering a protective role for cardiac damage in asymptomatic patients and would be a good marker for the initiation of changes in the heart. On the other hand, MMP-9 can be used as a marker for serious changes on the heart and would be associated with inflammation and fibrosis. Here, we consolidate all characteristics involving MMP-2 and MMP-9 in Chagas' disease based on current studies to clarify their participation on the inflammation/regulation and fibrosis, and the synergistic or antagonistic role between them.

Electrocardiographic and echocardiographic abnormalities in Chagas disease: findings in residents of rural Bolivian communities hyperendemic for Chagas disease

BACKGROUND

Chagas disease is a neglected and preventable tropical disease that causes significant cardiac morbidity and mortality in Latin America.

OBJECTIVES

This study sought to describe cardiac findings among inhabitants of rural communities of the Bolivian Chaco.

METHODS

The cardiac study drew participants from an epidemiologic study in 7 indigenous Guarani communities. All infected participants 10 years or older were asked to undergo a brief physical examination and 12-lead electrocardiogram (ECG). A subset had echocardiograms. ECG and echocardiograms were read by 1 or more cardiologists.

RESULTS

Of 1,137 residents 10 years or older, 753 (66.2%) had Trypanosoma cruzi infection. Cardiac evaluations were performed for 398 infected participants 10 years or older. Fifty-five participants (13.8%) had 1 or more ECG abnormalities suggestive of Chagas cardiomyopathy. The most frequent abnormalities were bundle branch blocks in 42 (11.3%), followed by rhythm disturbances or ventricular ectopy in 13 (3.3%), and atrioventricular blocks (AVB) in 10 participants (2.6%). The prevalence of any abnormality rose from 1.1% among those 10 to 19 years old to 14.2%, 17.3%, and 26.4% among those 20 to 39, 40 to 59, and older than 60 years, respectively. First-degree AVB was seen most frequently in participants 60 years or older, but the 4 patients with third-degree AVB were all under 50 years old. Eighteen and 2 participants had a left ventricular ejection fraction of 40% to 54% and <40%, respectively. An increasing number of ECG abnormalities was associated with progressively larger left ventricular end-diastolic dimensions and lower left ventricular ejection fraction.

CONCLUSIONS

We found a high prevalence of ECG abnormalities and substantial evidence of Chagas cardiomyopathy. Programs to improve access to basic cardiac care (annual ECG, antiarrhythmics, pacemakers) could have an immediate impact on morbidity and mortality in these highly endemic communities.

Biomarkers and mortality in severe Chagas cardiomyopathy

BACKGROUND

Chagas cardiomyopathy is a chronic sequela of infection by the parasite, Trypanosoma cruzi. Advanced cardiomyopathy is associated with a high mortality rate, and clinical characteristics have been used to predict mortality risk. Though multiple biomarkers have been associated with Chagas cardiomyopathy, it is unknown how these are related to survival.

OBJECTIVES

This study aimed to identify biomarkers associated with mortality in individuals with severe Chagas cardiomyopathy in an urban Bolivian hospital.

METHODS

The population included individuals with and without T. cruzi infection recruited in an urban hospital in Santa Cruz, Bolivia. Baseline characteristics, electrocardiogram findings, medications, and serum cardiac biomarker levels (B-type natriuretic peptide [BNP], N-terminal pro-B-type natriuretic peptide [NT-proBNP], creatine kinase-myocardial band [CK-MB], troponin I, matrix metalloproteinase [MMP]-2, MMP-9, tissue inhibitor of metalloproteinases [TIMP] 1 and 2, transforming growth factor [TGF] beta 1 and 2) were ascertained. Echocardiograms were performed on those with cardiac symptoms or electrocardiogram abnormalities at baseline. Participants were contacted approximately 1 year after initial evaluation; deaths were reported by family members. Receiver-operating characteristic curves (ROC) were used to optimize cutoff values for each marker. For markers with area under the curve (AUC) >0.55, Cox proportional hazards models were performed to determine the hazards ratio (HR) and 95% confidence interval (CI) for the association of each marker with mortality.

RESULTS

The median follow-up time was 14.1 months (interquartile range 12.5, 16.7). Of 254 individuals with complete cardiac data, 220 (87%) had follow-up data. Of 50 patients with severe Chagas cardiomyopathy at baseline, 20 (40%) had died. Higher baseline levels of BNP (HR: 3.1, 95% CI: 1.2 to 8.4), NT-proBNP (HR: 4.4, 95% CI: 1.8 to 11.0), CK-MB (HR: 3.3, 95% CI: 1.3 to 8.0), and MMP-2 (HR: 4.2, 95% CI: 1.5 to 11.8) were significantly associated with subsequent mortality.

CONCLUSIONS

Severe Chagas cardiomyopathy is associated with high short-term mortality. BNP, NT-proBNP, CK-MB, and MMP-2 have added predictive value for mortality, even in the presence of decreased ejection fraction and other clinical signs of congestive heart failure.

Inflammatory and cardiac biomarkers are differentially expressed in clinical stages of Chagas disease

BACKGROUND

Chagas disease has a long clinically silent period following Trypanosoma cruzi infection and before development of overt clinical pathology; detectable biomarkers of infection and pathogenesis are urgently needed. We tested 22 biomarkers known to be associated with cardiomyopathy to evaluate if a biomarker signature could successfully classify T. cruzi seropositive subjects into clinical Chagas disease stage groups.

METHODS

This cross-sectional retrospective case-control study enrolled T. cruzi seropositive blood donors (BD) who were further characterized as having chronic Chagas cardiomyopathy (CC-BD) or not (nonCC-BD) and seronegative (SN) control donors; we also included clinically diagnosed Chagas cardiomyopathy patients (CC-P). All subjects underwent a health history questionnaire, medical examination, electro- and echocardiograms (ECG and Echo) and phlebotomy. Biomarkers were measured on blinded samples by luminex bead array and Ortho VITROS.

RESULTS

A clear biomarker pattern was observed only in more severe cardiac disease; this pattern included significantly elevated levels of inflammatory cytokines IFN-γ, IL-6, IL-10 and TNF-α and soluble cardiovascular disease biomarkers CK-MB, troponin, myoglobin, VCAM and NTproBNP while there were lower levels of MPO, PAI-1, and MCP-1. The markers determined to be the most predictive of disease by ROC curve analysis were NTproBNP and T. cruzi PCR status.

CONCLUSIONS

Although many biomarkers demonstrated increased or decreased concentrations among the clinical forms of Chagas disease, NTproBNP and T. cruzi PCR were the only tests that would independently be of clinical value for disease staging, in concert with ECG, Echo and clinical assessments.