A recombinant chimeric antigen constructed with B-cell epitopes from Mycobacterium leprae hypothetical proteins is effective for the diagnosis of leprosy.

The diagnosis if leprosy is difficult, as it requires clinical expertise and sensitive laboratory tests. In this study, we develop a serological test for leprosy by using bioinformatics tools to identify specific B-cell epitopes from Mycobacterium leprae hypothetical proteins, which were used to construct a recombinant chimeric protein, M1. The synthetic peptides were obtained and showed good reactivity to detect leprosy patients, although the M1 chimera have showed sensitivity (Se) and specificity (Sp) values higher than 90.0% to diagnose both paucibacillary (PB) and multibacillary (MB) leprosy patients, but not those developing tegumentary or visceral leishmaniasis, tuberculosis, Chagas disease, malaria, histoplasmosis and aspergillosis, in ELISA experiments. Using sera from household contacts, values for Se and Sp were 100% and 65.3%, respectively. In conclusion, our proof-of-concept study has generated data that suggest that a new recombinant protein could be developed into a diagnostic antigen for leprosy.

Influence of polymorphisms in CYP2C9, VKORC1, MDR1 and APOE genes on the warfarin maintenance dose in Brazilian patients.

Background: Polymorphisms in the CYP2C9, VKORC1, MDR1 and APOE genes may impact warfarin dose. Aim: To investigate the influence of sociodemographic, clinical factors and polymorphisms *1, *2 and *3 for CYP2C9, -1639G>A for VKORC1, 3435C>T for MDR1, and ϵ2, ϵ3 and ϵ4 for APOE genes on the mean weekly warfarin maintenance dose in adults. Methods: This cross-sectional study recruited a calculated sample of 315 patients in three anticoagulation clinics in Brazil. A model containing the variables significantly associated with warfarin dose was estimated. Results: The mean age of patients was 64.1 ± 13.1 years, with 173 (54.9%) women. Age, use of amiodarone, genotype VKORC1 GA, genotype VKORC1 AA, genotypes CYP2C9*1/*2 or *1/*3 and genotypes CYP2C9*2/*2 or *2/*3 or *3/*3 were associated with a reduced warfarin dose. Conclusion: This study pointed out factors that could impact the management of oral anticoagulation.

Functional predictors of poor outcomes in Chagas cardiomyopathy: The value of end-tidal carbon dioxide at peak exercise.

BACKGROUND: Functional impairment can be detected from the onset of heart disease in patients with Chagas cardiomyopathy (ChC) and the prognostic value of the end-tidal carbon dioxide at peak exercise (PETCO2 peak) should be investigated. OBJECTIVE: To verify the prognostic value of PETCO2 peak in patients with ChC. METHODS: Seventy-six patients with ChC (49.2 ± 9.8 years, NYHA I-III) were evaluated by echocardiography and Cardiopulmonary Exercise Testing. Patients were followed up to four years and the end-point was defined as cardiovascular death, stroke, or cardiac transplantation. RESULTS: At the end of the follow-up period (29.0 ± 16.0 months), 16 patients (21%) had experienced adverse events. The area under the receiver operating characteristic (ROC) curve to identify the risk of adverse events by PETCO2 peak in patients with ChC was 0.83 (95% CI: 0.69 to 0.97), and the value of 32 mmHg was the optimal cut point (70% of sensitivity and 85% of specificity). In the Kaplan-Meier diagram, there was a significant difference (p<0.001) between patients with reduced (≤ 32 mmHg) and preserved PETCO2 peak (>32 mmHg). In the final Cox multivariate model, only reduced PETCO2 peak (HR 4.435; 95% CI: 1.228 to 16.016, p = 0.023) and VO2peak (HR 0.869; 95% CI: 0.778 to 0.971, p = 0.013) remained as independent predictors of poor outcome in ChC patients. CONCLUSION: Reduced PETCO2 peak and VO2peak demonstrated valuable prognostic value in patients with ChC. The cutoff points for both functional variables can be used during risk stratification and may help in the development of therapeutic strategies in ChC patients.

Intestinal permeability evaluation in patients with chronic Chagas heart failure.

AIMS: We analysed intestinal permeability in patients with chronic Chagas cardiomyopathy (CCC) and evaluated its association with clinical manifestations, haemodynamic parameters measured by echocardiogram, and disease outcome. Intestinal permeability was compared between CCC patients and a group of healthy controls. BACKGROUND: Intestinal dysfunction may contribute to a more severe disease presentation with worse outcome in patients with CCC and heart failure. METHODS: Fifty patients with CCC and left ventricular ejection fraction (LVEF) of less than 55% were prospectively selected and followed for a mean period of 18 ± 8 months. A group of 27 healthy volunteers were also investigated. One patient was excluded from the analysis since he died before completing the intestinal permeability test. Intestinal permeability was evaluated with the sugar probe drink test. It consists in the urinary recovery of previously ingested sugar probes: mannitol, a monosaccharide, and lactulose, a disaccharide. RESULTS: Patient's mean age was 53.4 ± 10.4 years, and 31(63%) were male. Differential urinary excretion of lactulose/mannitol ratio did not differ significantly between healthy controls and CCC patients, regardless of clinical signs of venous congestion, haemodynamic parameters, and severity of presentation and outcome. CONCLUSIONS: The present study could not show a disturbance of the intestinal barrier in CCC patients with LVEF <55%, measured by lactulose/mannitol urinary excretion ratio. Further investigations are needed to verify if in patients with LVEF <40% intestinal permeability is increased.

Chagasic cardiomyopathy is marked by a unique signature of activated CD4+ T cells.

Chagas disease is a neglected tropical disease in Latin America and an imported emerging disease worldwide. Chronic Chagas disease cardiomyopathy (CCC) is the most prominent clinical form and can lead to heart failure, thromboembolism, and sudden death. While previous reports have supported a role for CD4+ T lymphocytes in the pathogenesis of CCC a comprehensive analysis of these cells during different clinical forms is lacking. Here, we used high-dimensional flow cytometry to assess the diversity of circulating CD4+ T cells in patients with distinct clinical forms. We found increased frequencies of CD4+CD69+ T cells in patients compared to controls. CD39+ regulatory T cells, represented by mesocluster 6 were reduced in mild CCC patients compared to controls. Cytotoxic CD4+ T cells co-expressing granzyme B and perforin were expanded in patients with Chagas disease and were higher in patients with mild CCC compared to controls. Furthermore, patients with mild CCC displayed higher frequencies of multifunctional effector memory CD4+ T cells. Our results demonstrate an expansion in activated CD4+ T cells and a decrease in a functional subset of regulatory T cells associated with the onset of Chagas cardiomyopathy, suggesting their role in the establishment of cardiac lesions and as potential biomarkers for disease aggravation.

Development of an immunogen containing CD4+/CD8+ T-cell epitopes for the prophylaxis of tegumentary leishmaniasis.

Tegumentary leishmaniasis (TL) is a disease of high severity and incidence in Brazil, and Leishmania braziliensis is its main etiological agent. The inefficiency of control measures, such as high toxicity and costs of current treatments and the lack of effective immunoprophylactic strategies, makes the development of vaccines indispensable and imminent. In this light, the present work developed a gene encoding multiple T-cell (CD4+/CD8+) epitope, derived from conserved proteins found in Leishmania species and associated with TL, to generate a chimeric protein (rMEP/TL) and compose a vaccine formulation. For this, six T-cell epitopes were selected by immunoinformatics approaches from proteins present in the amastigote stage and associated with host-parasite interactions. The following formulations were then tested in an L. braziliensis murine infection model: rMEP/TL in saline or associated with MPLA-PHAD®. Our data revealed that, after immunization (three doses; 14-day intervals) and subsequent challenging, rMEP/TL and rMEP/TL + MPLA-vaccinated mice showed an increased production of key immunological biomarkers of protection, such as IgG2a, IgG2a/IgG1, NO, CD4+, and CD8+ T-cells with IFN-γ and TNF-α production, associated with a reduction in CD4+IL-10+ and CD8+IL-10+ T-cells. Vaccines also induced the development of central (CD44highCD62Lhigh) and effector (CD44highCD62Llow) memory of CD4+ and CD8+ T-cells. These findings, associated with the observation of lower rates of parasite burdens in the vaccinated groups, when compared to the control groups, suggest that immunization with rMEP/TL and, preferably, associated with an adjuvant, may be considered an effective tool to prevent TL. KEY POINTS: • Rational design approaches for vaccine development. • Central and effector memory of CD4+ and CD8+ T-cells. • Vaccine comprised of rMEP/TL plus MPLA as an effective tool to prevent TL.

Accuracy of health-related quality of life in identifying systolic dysfunction in patients with Chagas cardiomyopathy.

OBJECTIVE: Systolic dysfunction is a well-established marker of mortality in patients with Chagas cardiomyopathy (CC). However, its diagnosis is expensive and useful tools for screening these patients are required. The evaluation of the health-related quality of life (HRQoL) detects the patient's perception of the disease's impact. However, its accuracy in identifying patients with CC and systolic dysfunction is unknown. The study aimed to verify the sensitivity, specificity and predictive values of the physical and mental components related to HRQoL in identifying patients with CC and systolic dysfunction. METHODS: 75 patients with CC, aged 49 (95% confidence interval: 47-51) years, were evaluated by echocardiography and Short-Form of Health Survey (SF-36) questionnaire. Systolic dysfunction was defined by left ventricular ejection fraction <52% for men and <54% for women and left ventricular diastolic diameter >55 mm. RESULTS: Most patients (73%) had systolic dysfunction, with lower HRQoL values in the physical functioning, physical role functioning and general health perceptions domains and in the physical component summary. The accuracy of identifying patients with systolic dysfunction by the scores of physical components was 73% and 62% of mental components. The optimal cut-off point was 46 for physical and 54 for mental components, with respective positive predictive values of 91% and 80%. CONCLUSION: The evaluation of the HRQoL by the SF-36, a low-cost instrument, can be useful in identifying patients with systolic dysfunction, assisting in the screening and risk stratification of patients.

Hypovitaminosis D and reduced cathelicidin are strongly correlated during the multidrug therapy against leprosy.

Mycobacterium leprae infection depends on the competence of the host immune defense to induce effective protection against this intracellular pathogen. The present study investigated the serum levels of vitamin D and the antimicrobial peptide cathelicidin, to determine the statistical correlation between them in leprosy patients before and post-six months of multidrug therapy (MDT), household contacts, and healthy individuals. Previous studies associated these molecules with high risks to develop mycobacterial diseases, such as tuberculosis and leprosy. A total of 34 leprosy patients [paucibacillary (n = 14), multibacillary (n = 20)], and 25 household contacts were recruited. Eighteen healthy adults were selected as a control group. Serum concentrations of vitamin D (25(OH)VD3) and cathelicidin were measured using high-performance liquid chromatography (HPLC), and an enzyme-linked immunosorbent assay (ELISA) kit, respectively. There were no significant differences in serum levels of 25(OH)VD3 between all groups, and the overall prevalence rate of vitamin D deficiency was 67.1%. Cathelicidin levels were significantly lower in both untreated and treated patients when compared to controls and household contacts (p < 0.05). Strong correlations between hypovitaminosis D and reduced cathelicidin in untreated (r = 0.86) and post-six months of MDT (r = 0.79) leprosy patients were observed. These results suggest that vitamin D status and cathelicidin levels are strongly correlated during multidrug therapy for leprosy and nutritional supplementation from the beginning of treatment could strengthen the immune response against leprosy.

Algorithm for predicting low maintenance doses of warfarin using age and polymorphisms in genes CYP2C9 and VKORC1 in Brazilian subjects.

Warfarin exhibits a wide variation in dose requirements. We sought to evaluate the association of polymorphisms CYP2C9*2 (rs1799853), CYP2C9*3 (rs1075910), and VKORC1-G1639A (rs9923231) and nongenetic factors with maintenance doses of warfarin <17.5 mg/week and to create an algorithm to predict drug sensitivity. This is a retrospective cohort study including 312 patients assisted at an anticoagulation clinic in Brazil. The mean age of participants was 60.4 ± 13.5 years and 59.9% were female. The logistic regression model included: age [odds ratio (OR) 1.03, 95% confidence interval (CI) 1.01-1.06], genotype VKORC1 AA (OR 31.61, 95% CI 11.20-100.15) and genotype CYP2C9 2/2, 2/3 or 3/3 (OR 16.48, 95% CI 3.37-81.79). The creation of our algorithm involved warfarin-experienced patients on stable doses, identifying factors associated with drug sensitivity. The validation of this algorithm allows its use in future populations to determine the initial dose distinguishing patients with dose requirements <17.5 mg and reducing time to achieve stable doses.

Speckle tracking echocardiographic deformation indices in Chagas and idiopathic dilated cardiomyopathy: Incremental prognostic value of longitudinal strain.

BACKGROUND: Chagas cardiomyopathy (CDC) is associated with a poor prognosis compared to other cardiomyopathies. Speckle tracking echocardiography (STE), which provides direct assessment of myocardial fiber deformation, may be useful in predicting prognosis. OBJECTIVE: This study assessed STE in CDC and compared with idiopathic cardiomyopathy (IDC), and also examined the incremental prognostic information of STE over left ventricular ejection fraction (LVEF) in these patients. METHODS: We enrolled 112 patients, age of 56.7 ± 11.8 years, 81 with CDC and 31 with IDC. STE indices were obtained at baseline in all patients. The endpoint was a composite of death, hospitalization for heart failure, or need for heart transplantation. RESULTS: Patients with IDC had worse LV systolic function compared to CDC, with LVEF of 34.5% vs 41.3%, p = 0.004, respectively. After adjustment for LVEF, there were no differences in STE values between CDC and IDC. During a median follow-up of 18.2 months (range, 11 to 22), 26 patients met the composite end point (24%). LV longitudinal strain was a strong predictor of adverse events, incremental to LVEF and E/e' ratio (HR 1.463, 95% CI 1.130-1.894; p = 0.004). The risk of cardiac events increased significantly in patients with GLS > - 12% (log-rank p = 0.035). CONCLUSIONS: STE indices were abnormal in patients with dilated cardiomyopathy, without differences between CDC and IDC. LV longitudinal strain was a powerful predictor of outcome, adding prognostic information beyond that provided by LVEF and E/e' ratio.

The prognostic value of health-related quality of life in patients with Chagas heart disease.

PURPOSE: To verify the prognostic value of health-related quality of life (HRQoL) and the differences in HRQoL and clinical variables between groups of Chagas heart disease (CHD) patients with and without cardiovascular adverse events. METHODS: Seventy-five CHD patients were evaluated by echocardiography, maximal exercise testing, and Short-form of Health Survey (SF-36) Questionnaire. Patients were followed during 6 years. In the statistical analysis, uni- and multivariate Cox regression were performed to verify the accuracy of the HRQoL in predicting cardiovascular events. RESULTS: After the follow-up period (41 ± 12 months), 20 patients (27%) had adverse events. Those with poor outcome had lower left ventricular ejection fraction (LVEF) (p = 0.002), higher left ventricular end-diastolic diameter (LVDd) (p = 0.019), and worse scores in general health perceptions (p = 0.047), social role functioning (p = 0.026), and mental component summary (p = 0.043) of SF-36. Patients with lower LVEF (p = 0.003), higher LVDd (p = 0.022), worse HRQoL in the general heath perceptions domain (p = 0.022), and mental component summary (p = 0.031) were associated with worse prognosis. In the multivariate Cox regression, LVEF (HR 0.94, 95% CI from 0.90 to 0.98, p = 0.007) and mental component summary (HR 0.98, 95% CI from 0.94 to 1.00, p = 0.047) remained as independent predictors of adverse events in CHD patients. CONCLUSION: The assessment of HRQoL, especially the mental component, should be taken into account to provide an accurate prognosis in addition to other well-established predictors of poor outcomes in CHD patients.

Six-minute walk test and incremental shuttle walk test in the evaluation of functional capacity in Chagas heart disease.

Chagas heart disease (CHD) leads to a progressive functional impairment. Field tests, as the 6-min walk test (6MWT) and the incremental shuttle walk test (ISWT), may be inexpensive approaches in the evaluation of functional capacity of these patients. The present study was addressed to compare the 6MWT and the ISWT measures, and to determine the accuracy of these tests in the identification of functional impairment in patients with CHD. Thirty-five patients with CHD (47.1±8.2 years, NYHA I-III) were evaluated by echocardiography, cardiopulmonary exercise test (CPET), 6MWT, and ISWT. Correlations between the CPET (peak oxygen uptake [peak VO2] and the ratio between ventilation and the carbon dioxide production [VE/VCO2 slope]) and the field tests (walking distances) were also performed. The receiver operating characteristic (ROC) curve was selected to identify the best distances related to identify those patients with functional impairment. There was no difference between distances walked during the 6MWT and ISWT (P=0.694). The Bland-Altman analysis showed good agreement between the field tests. Both 6MWT and ISWT correlated with peak VO2 (r=0.577, P<0.001 and r=0.587, P<0.001, respectively) and ISWT correlated with VE/VCO2 slope (r=-0.339, P=0.003). The cutoff distances of 6MWT and ISWT to identify patients with peak VO2 less than 20 mL/kg/min were 520 m and 400 m, respectively, with no difference between the areas under ROC curves (P=0.276). Both the 6MWT and the ISWT demonstrated accuracy in identify functional impairment in patients with CHD, being useful tools for the risk stratification of these patients.

Immunogenomic screening approach to identify new antigens for the serological diagnosis of chronic Chagas' disease.

Serological tests are preferentially used for the diagnosis of Chagas' disease (CD) during the chronic phase because of the low parasitemia and high anti-Trypanosoma cruzi antibody titers. However, the current methods showed several disadvantages, as contradictory or inconclusive results, mainly related to the characteristics of the antigens used, in general, crude or whole parasites, but also due to antigen production protocol and the experimental conditions used in serological tests. Thus, better-quality serological assays are urgently needed. Here, we performed a wide immunogenomic screen strategy to identify conserved linear B-cell epitopes in the predicted proteome based on genome sequence from T. cruzi strains to will be applied as synthetic peptides in the serodiagnosis of the chronic CD. Three B-cell epitopes derived from mucin-associated surface protein (MASP) family, expressed in both infective parasite stages, trypomastigote and amastigotes, conserved in T. cruzi strains, and highly divergent as compared with Leishmania spp. proteome, were selected for this study. The results demonstrated that synthetic peptide 2 and a mixture of peptides (Mix II: peptides 2 and 3) were able to identify all chronic CD cases, indeterminate or Chagas cardiomyopathy clinical presentation, and simultaneously able to discriminate infections caused by Leishmania parasites, with high accuracy (98.37 and 100.00%, respectively) and agreement (kappa index = 0.967 and 1.000, respectively) with direct methods as compared to current diagnostic pipeline performed by reference laboratories in Brazil. This study represents an interesting strategy for the discovery of new antigens applied to serologic diagnosis of infectious diseases and for the technological development of platforms for large-scale production of diagnostic tests.

Usefulness of microvolt T-wave alternans for predicting outcome in patients with Chagas disease with implantable cardioverter defibrillators.

BACKGROUND: Chagas disease (ChD) may lead to life-threatening heart disease, including malignant ventricular arrhythmias. The use of implantable cardioverter defibrillators (ICDs) has become the main therapeutic strategy for secondary prevention of SCD in Chagas disease (ChD). Microvolt T-wave alternans (MTWA) is a direct measure of ventricular repolarization instability and has emerged as a potentially useful way of determining arrhythmia vulnerability. However, this methodology has not been evaluated in patients with ChD. OBJECTIVE: To evaluate the predictive value of MTWA testing for appropriate therapy or death in ChD patients with ICDs. METHODS: This prospective study included consecutive patients who received ICD implantations in a Brazilian tertiary referral center. RESULTS: Seventy-two patients were followed for a median time of 422 (range 294-642) days. Thirty-three patients had ChD. The MTWA was non-negative (positive or indeterminate) in 27 (81.8%) of ChD patients. The combined primary outcome (appropriate ICD therapy or death) occurred in 29 patients (40.3%); 17 out 33 ChD patients presented the primary outcome. There was a statistically significant difference in event-free survival between ChD patients with negative and non-negative MTWA results (p=0.02). Non-negative MTWA tests nearly triple the risk of appropriate ICD therapy or death (HR=2.7, 95% CI: 1.7-4.4, p=0.01) in patients with ChD and was the only variable associated with outcomes. The sensitivity and the negative predictive value was 100% in ChD patients. CONCLUSIONS: MTWA may be useful in recognizing high-risk ICD patients who may require adjunctive therapies with antiarrhythmic drugs or catheter ablation.

Immunoregulatory mechanisms in Chagas disease: modulation of apoptosis in T-cell mediated immune responses.

BACKGROUND: Chronic Chagas disease presents different clinical manifestations ranging from asymptomatic (namely indeterminate) to severe cardiac and/or digestive. Previous results have shown that the immune response plays an important role, although no all mechanisms are understood. Immunoregulatory mechanisms such as apoptosis are important for the control of Chagas disease, possibly affecting the morbidity in chronic clinical forms. Apoptosis has been suggested to be an important mechanism of cellular response during T. cruzi infection. We aimed to further understand the putative role of apoptosis in Chagas disease and its relation to the clinical forms of the disease. METHODS: Apoptosis of lymphocytes, under antigenic stimuli (soluble T. cruzi antigens - TcAg) where compared to that of non-stimulated cells. Apoptosis was evaluated using the expression of annexin and caspase 3(+) by T cells and the percentage of cells positive evaluated by flow cytometry. In addition activation and T cell markers were used for the identification of TCD4(+) and TCD8(+) subpopulations. The presence of intracellular and plasma cytokines were also evaluated. Analysis of the activation status of the peripheral blood cells showed that patients with Chagas disease presented higher levels of activation determined by the expression of activation markers, after TcAg stimulation. PCR array were used to evaluate the contribution of this mechanism in specific cell populations from patients with different clinical forms of human Chagas disease. RESULTS: Our results showed a reduced proliferative response associated a high expression of T CD4(+)CD62L(-) cells in CARD patients when compared with IND group and NI individuals. We also observed that both groups of patients presented a significant increase of CD4(+) and CD8(+) T cell subsets in undergoing apoptosis after in vitro stimulation with T. cruzi antigens. In CARD patients, both CD4(+) and CD8(+) T cells expressing TNF-α were highly susceptible to undergo apoptosis after in vitro stimulation. Interestingly, the in vitro TcAg stimulation increased considerably the expression of cell death TNF/TNFR superfamily and Caspase family receptors genes in CARD patients. CONCLUSIONS: Taken together, our results suggest that apoptosis may be an important mechanism for the control of morbidity in T. cruzi infection by modulating the expression of apoptosis genes, the cytokine environment and/or killing of effector cells.

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.

Inflammatory mediators from monocytes down-regulate cellular proliferation and enhance cytokines production in patients with polar clinical forms of Chagas disease.

Exposure to Trypanosoma cruzi parasites induces monocytes and macrophages to produce various endogenous mediators, including prostaglandins and cytokines. To clarify the involvement of monocytes as an important source of inflammatory mediators in Chagas disease patients, we evaluated PBMC before and after depletion of adherent cells (monocytes) from patients with indeterminate (IND) and cardiac (CARD) clinical forms and from non-infected individuals (NI). We demonstrated that after the partial depletion of adherent cells, production of PGE2 was slightly decreased in patients with Chagas disease. Inhibition of the cells by indomethacin increased the proliferation in PBMC cells from patients after antigen stimulation. Pro-inflammatory cytokines as IL-2 and IFN-γ also had a greater decrease after partial depletion of adherent cells in both clinical forms of Chagas disease. IL-10 and IL-5 levels were also reduced after partial depletion of adherent cells both in IND and CARD patients. In addition, we evaluated the APC potential of B cells and observed that the MHCII and CD80 molecules had an increased expression after partial depletion of most monocytes in all groups. Thus, inflammatory mediators produced by monocytes seem to be important to modulate immune responses in Chagas disease by regulating the processes of inflammation and antigen presentation.

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.