Plasma levels of soluble TNF receptors are associated with cardiac function in patients with Chagas heart disease

TNF blockers alone and associated with Benznidazole impact in vitro cytokine dynamics in chronic Chagas disease

Studies involving the immune response in Chagas disease suggest an imbalance in the immune response of symptomatic patients, with an inflammatory profile dominating in Chagas heart disease, mainly by tumour necrosis factor (TNF). TNF is considered a key cytokine in immunopathology in chronic carriers in several processes during the immune response. Our work aimed to evaluate regulatory (interleukin [IL]-4 and IL-10) and inflammatory (TNF, interferon-gamma [IFN-γ], IL-2 and IL-6) cytokines in peripheral blood mononuclear cells culture supernatants. of affected patients with undetermined clinical forms-IND (n = 13) mild heart form-CARD1 (n = 13) and severe cardiac form-CARD2 (n = 16), treated in vitro with two TNF blockers, Adalimumab (ADA) and Etanercept (ETA) alone or in association with Benznidazole (BZ). The results indicate that ADA was more competent in blocking TNF (compared to ETA) in all groups but with much lower levels in the CARD2 group. ETA statistically decreased TNF levels only in the CARD2 group. IFN-γ increased in the CARD2 group after treatment with ETA relative to ADA. IL-4 had its levels decreased when treated by both drugs. IL-2 was detected in cells from CARD2 carriers compared to the NEG group after treatment with both drugs. The association with BZ decreased levels of IL-2/TNF and increased IL-4. These data reinforce the participation of TNF in severe Chagas heart disease and bring perspectives on using these blockers in the immunological treatment of Chagas disease since the use of BZ is extremely limited in these patients.

Cytokine profile levels and their relationship with parasitemia and cardiomyopathy in people with Chagas disease in Spain. A prospective observational study

Immunoregulatory networks may have a role in controlling parasitemia in the chronic phase of human Chagas disease. The aim was to describe the serum cytokine profile of Trypanosoma cruzi in chronically infected patients and to evaluate its relationship with parasitemia and Chagas cardiomyopathy.This prospective observational study included adult patients with chronic Chagas disease. Demographic and clinical data were collected, and peripheral blood samples were used to perform T. cruzi real-time polymerase chain reaction (RT-PCR) and determine the serum cytokine profile.Fifty-eight patients were included; 17 (29.3%) had positive RT-PCR results. This group had a higher median concentration of TNF-α (p = 0.003), IL-6 (p = 0.021), IL-4 (p = 0.031), IL-1β (p = 0.036), and IL-17A (p = 0.043) than those with a negative RT-PCR. Patients with cardiac involvement had a higher median concentration of IL-5 (p = 0.016) than those without.These results reinforce the key role that cytokines play in Chagas disease patients with parasitemia and cardiac involvement.

Blocking activation of CD4-CD8- T cells modulates their cytotoxic potential and decreases the expression of inflammatory and chemotactic receptors

CD4-CD8- (double negative - DN) T cells represent a small fraction of circulating T lymphocytes but are a major source of pro-inflammatory cytokines in patients with infectious diseases, including chronic Chagas cardiomyopathy (CCC), one of the deadliest cardiopathies known. Chagas disease is caused by an infection with the protozoan parasite Trypanosoma cruzi and can lead to either an asymptomatic form or a high-mortality cardiac disease. While circulating DN T cells represent a major inflammatory cytokine-expressing cell population in Chagas disease, their potential to be recruited to the heart and to perform cytotoxicity has not been determined. Our previous studies showed that blocking DN T cell activation decreases the expression of IFN-gamma, a cytokine involved in the severity of CCC. Here, studying a well-characterized cohort of Chagas patients with CCC or the asymptomatic form of Chagas disease (indeterminate form, IND), we evaluated the expression of cytotoxic molecules, cytokine and chemokine receptors in γδ+ and αβ+ DN T cells by multiparameter flow cytometry, and investigated whether blocking the activation of DN T cells influences the expression of these molecules. We observed that DN T cells from CCC display a higher expression of granzyme A, perforin, inflammatory molecules, and inflammatory chemokine receptors than cells from IND. Messenger RNA coding for these molecules is also upregulated in the heart of CCC patients. Importantly, blocking the activation of DN T cells from CCC modulates their cytotoxic potential and the expression of inflammatory and of chemokine receptors, suggesting that targeting DN T cell activation may be a valid strategy to reduce recruitment to the heart, inflammation, cytotoxicity and, thereby diminish CCC progression and severity.

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.

Is a negative correlation between sTNFR1 and TNF in patients with chronic Chagas disease the key to clinical progression?

Soluble TNF receptors (sTNFR1 and sTNFR2) are natural endogenous inhibitors of TNF and are elevated in inflammatory, autoimmune, and chronic degenerative diseases. In Chagas disease, pleiotropic cytokine TNF is considered key in immunopathology. Thus, we aimed to evaluate the levels of TNF, sTNFR1, and sTNFR2 in the serum of patients with chronic Chagas disease. TNF and its soluble receptors were quantified using Cytometric Bead Array in the serum of 132 patients, of which 51 had the indeterminate form (IND), 39 the mild cardiac form (CARD 1), 42 the severe cardiac form (CARD 2), and 20 non-infected individuals (NI). The results indicate that the soluble receptors may regulate TNF in Chagas disease, as their leves were higher in T. cruzi-infected individuals when compared to non-infected individuals. We found a moderate negative correlation between sTNFR1 and TNF in individuals with the IND form, suggesting a relationship with non-progression to more severe forms, such as heart disease. sTNFR1 and sTNFR2 were increased in all clinical forms, but with a moderate positive correlation in more severe patients (r = 0.50 and p = 0.0005). TNF levels showed no statistical differences in the groups of patients. These findings suggest the importance of the endogenous balance of the levels of soluble TNF receptors in the protection and balance in patients with chronic Chagas disease, besides revealing the immunological complexity in chronic T. cruzi-infected individuals.