Increased Natural Killer (NK)-cell cytotoxicity and Trypanosoma cruzi-specific memory B cells in subjects with discordant serology for Chagas disease.

The presence of memory T cell specific for Trypanosoma cruzi in subjects with discordant serology for Chagas disease supports a cleared infection in these subjects. Using high-dimensional flow cytometry, ELISPOT assays and quantitative PCR, antibody-secreting cells and memory B cells specific for T. cruzi, total B-cell phenotypes, innate immune responses and parasite DNA were evaluated in serodiscordant, seropositive and seronegative subjects for T. cruzi infection. T. cruzi-specific memory B cells but no antibody-secreting cells specific for T. cruzi, increased proportion of nonclassical monocytes and increased levels of polyfunctional NK cells were found in serodiscordant compared with seropositive subjects. None of the serodiscordant subjects evaluated showed detectable parasite DNA, most of them did not show cardiac abnormalities and a group of them had had confirmed positive serology for Chagas disease. The unique immune profiles in serodiscordant subjects support that T. cruzi infection was cleared or profoundly controlled in these subjects.

Resultados oncológicos del manejo neoadyuvante con quimiorradioterapia seguido de cirugía en cáncer de recto localmente avanzado: en el Instituto Oncológico Nacional de Panamá

Antecedentes y objetivos: Se reportan 720 000 nuevos casos cada año de cáncer de recto. En la etapa localmente avanzada (LARC), la terapia multimodal seguido de cirugía con escisión total del mesorrecto (TME) es el estándar de tratamiento con potenciales beneficios en toxicidad aguda, valoración de respuesta y resecabilidad. El objetivo es describir las características clínico-patológicas y resultados oncológicos en pacientes tratados con quimiorradioterapia neoadyuvante seguido de cirugía radical. Materiales y métodos: Estudio descriptivo, no experimental, transversal y retrospectivo en donde se analizaron 141 pacientes con diagnóstico de LARC definido como cT3T4N0 o cTXN+M0 programados para tratamiento con quimiorradioterapia neoadyuvante en el Instituto Oncológico Nacional durante el período de enero 2014 a diciembre 2019. Resultados: Un total de 119 pacientes completaron quimiorradioterapia neoadyuvante seguido de cirugía radical resultando en una resecabilidad de 90.1%. La tasa global de complicaciones posoperatorias fue de 17.4%. La tasa de pCR (La respuesta patológica completa) y desvalorización fue 19.6% y 70.6% respectivamente. La categoría N preoperatoria fue la única variable con un impacto estadísticamente significativo con respecto a la pCR vs no pCR (p = 0.04). La mediana de seguimiento fue de 39 meses, obteniendo una supervivencia global a 5 años de 69% y una supervivencia libre de enfermedad a 5 años de 74.4%.   Conclusiones: En el Instituto Oncológico Nacional de Panamá, el tratamiento del LARC con curso largo de quimiorradioterapia seguido de cirugía radical demostró una alta adherencia al tratamiento con una tasa de respuesta patológica completa y control local en concordancia con lo reportado a nivel internacional. (provisto por Infomedic International)

Background and objectives: 720,000 new cases of rectal cancer are reported each year. In the locally advanced stage (LARC), multimodal therapy followed by surgery with total mesorectal excision (TME) is the standard of care with potential benefits in acute toxicity, response assessment and resectability. The objective is to describe the clinicopathological characteristics and oncological results in patients treated with neoadjuvant chemoradiation therapy followed by radical surgery. Methods: A descriptive, non-experimental, cross-sectional and retrospective study in which the clinical records of 141 patients diagnosed with LARC defined as cT3T4N0 or cTXN+M0 scheduled for treatment with neoadjuvant chemoradiation therapy at the National Oncology Institute during the period from January 2014 to December 2019 were analyzed. Results: A total of 119 patients completed neoadjuvant chemoradiotherapy followed by radical surgery, resulting in a resectability of 90.1%. The overall rate of postoperative complications was 17.4%. The pCR and downstaging rate was 19.6% and 70.6%, respectively. Preoperative N category was the only variable with a statistically significant impact regarding pCR vs no pCR (p = 0.04). The median follow-up was 39 months, obtaining a 5-year overall survival of 69% and a 5-year disease-free survival of 74.4%. Conclusion: At the National Oncology Institute of Panama, the treatment of LARC with a long course of chemoradiation therapy followed by surgery with curative intent demonstrated high adherence to treatment with a rate of complete pathological response and local control in accordance with international reports. (provided by Infomedic International)

Mixed T Helper1/T Helper2/T Cytotoxic Profile in Subjects with Chronic Chagas Disease with Hypersensitivity Reactions to Benznidazole.

Dermatitis is the most common adverse event during treatment with benznidazole in chronic Chagas disease and is probably mediated by T cells. A set of molecules representative of the different type IV hypersensitivity reactions was evaluated in the circulation and skin biopsies of Trypanosoma cruzi-infected subjects presenting dermatitis during benznidazole administration. Through cytometric bead assays and enzyme-linked immunosorbent assay capture techniques, the serum levels of cytokines, chemokines, proapoptotic molecules, and mediators of the activation and migration of eosinophils and T cells were measured in subjects infected with Trypanosoma cruzi who exhibited skin adverse events (n = 22) and compared with those without adverse events (n = 37) during benznidazole therapy. Serum levels of interleukin- 5 (IL-5), soluble Fas cell surface death receptor ligand (FAS-L), and interferon γ-induced protein (IP-10) significantly increased at 7 to 30 days posttreatment with benznidazole and decreased thereafter in subjects with dermatitis but not in those without dermatitis. Circulating eotaxin levels were lower in subjects with dermatitis than in those without. Two patterns emerged in the skin biopsies: a T helper 1/T cytotoxic profile and a T helper 2/T cytotoxic profile with the presence of CD4+ and CD8+ T cells. Increased low-density lipoprotein (LDL), glutamic-oxaloacetic transaminase (GOT), uremia, and T cell activation emerged as risk factors for the development of dermatitis during benznidazole administration. These results support a delayed-type hypersensitivity reaction to benznidazole, involving CD4+ and CD8+ T cells and eosinophils, and a mixed cytokine profile. This study provides new insights for better management of adverse drug reactions to benznidazole. IMPORTANCE This study identified the risk factors for the development of adverse reactions to benznidazole and identified a set molecule to monitor the appearance of these reactions. This knowledge might improve the safety of benznidazole administration.

Role of the Complement System in the Modulation of T-Cell Responses in Chronic Chagas Disease.

Chagas disease, caused by the intracellular pathogen Trypanosoma cruzi, is the parasitic disease with the greatest impact in Latin America and the most common cause of infectious myocarditis in the world. The immune system plays a central role in the control of T. cruzi infection but at the same time needs to be controlled to prevent the development of pathology in the host. It has been shown that persistent infection with T. cruzi induces exhaustion of parasite-specific T cell responses in subjects with chronic Chagas disease. The continuous inflammatory reaction due to parasite persistence in the heart also leads to necrosis and fibrosis. The complement system is a key element of the innate immune system, but recent findings have also shown that the interaction between its components and immune cell receptors might modulate several functions of the adaptive immune system. Moreover, the findings that most of immune cells can produce complement proteins and express their receptors have led to the notion that the complement system also has non canonical functions in the T cell. During human infection by T. cruzi, complement activation might play a dual role in the acute and chronic phases of Chagas disease; it is initially crucial in controlling parasitemia and might later contributes to the development of symptomatic forms of Chagas disease due to its role in T-cell regulation. Herein, we will discuss the putative role of effector complement molecules on T-cell immune exhaustion during chronic human T. cruzi infection.

Immune exhaustion in chronic Chagas disease: Pro-inflammatory and immunomodulatory action of IL-27 in vitro.

In chronic Chagas disease, Trypanosoma cruzi-specific T-cell function decreases over time, and alterations in the homeostatic IL-7/IL-7R axis are evident, consistent with a process of immune exhaustion. IL-27 is an important immunoregulatory cytokine that shares T-cell signaling with IL-7 and other cytokines of the IL-12 family and might be involved in the transcriptional regulation of T-cell function. Here, we evaluated the expression and function of IL-27R in antigen-experienced T cells from subjects with chronic Chagas disease and assessed whether in vitro treatment with IL-27 and IL-7 might improve T. cruzi-specific polyfunctional T-cell responses. In vitro exposure of PBMCs to T. cruzi induced a downregulation of IL-27R in CD4+ T cells and an upregulation in CD8+ T cells in subjects without heart disease, while IL-27R expression remained unaltered in subjects with more severe clinical stages. The modulation of IL-27R was associated with functional signaling through STAT3 and STAT5 and induction of the downstream genes TBX21, EOMES and CXCL9 in response to IL-27. In vitro treatment of PBMCs with IL-27 and IL-7 improved monofunctional and polyfunctional Th1 responses, accompanied by the induction of IL-10 and Bcl-2 expression in subjects without heart disease but did not improve those in subjects with cardiomyopathy. Our findings support the process of desensitization of the IL-27/IL-27R pathway along with disease severity and that the pro-inflammatory and immunomodulatory mechanisms of IL-27 might be interconnected.

Reduced Trypanosoma cruzi-specific humoral response and enhanced T cell immunity after treatment interruption with benznidazole in chronic Chagas disease.

BACKGROUND: Interruption of benznidazole therapy due to the appearance of adverse effects, which is presumed to lead to treatment failure, is a major drawback in the treatment of chronic Chagas disease. METHODS: Trypanosoma cruzi-specific humoral and T cell responses, T cell phenotype and parasite load were measured to compare the outcome in 33 subjects with chronic Chagas disease treated with an incomplete benznidazole regimen and 58 subjects treated with the complete regimen, during a median follow-up period of 48 months. RESULTS: Both treatment regimens induced a reduction in the T. cruzi-specific antibody levels and similar rates of treatment failure when evaluated using quantitative PCR. Regardless of the regimen, polyfunctional CD4+ T cells increased in the subjects, with successful treatment outcome defined as a decrease of T. cruzi-specific antibodies. Regardless of the serological outcome, naive and central memory T cells increased after both regimens. A decrease in CD4+ HLA-DR+ T cells was associated with successful treatment in both regimens. The cytokine profiles of subjects with successful treatment showed fewer inflammatory mediators than those of the untreated T. cruzi-infected subjects. High levels of T cells expressing IL-7 receptor and low levels of CD8+ T cells expressing the programmed cell death protein 1 at baseline were associated with successful treatment following benznidazole interruption. CONCLUSIONS: These findings challenge the notion that treatment failure is the sole potential outcome of an incomplete benznidazole regimen and support the need for further assessment of the treatment protocols for chronic Chagas disease.

Impaired frequencies and function of platelets and tissue remodeling in chronic Chagas disease.

Chronic inflammation, as a consequence of the persistent infection with Trypanosoma cruzi, leads to continuous activation of the immune system in patients with chronic Chagas disease. We have previously shown that increased sera levels of soluble P-selectin are associated with the severity of the cardiomyopathy distinctive of chronic Chagas disease. In this study, we explored the expression of biomarkers of platelet and endothelial activation, tissue remodeling, and mediators of the coagulation cascade in patients at different clinical stages of chronic Chagas heart disease. The frequencies of activated platelets, measured by the expression of CD41a and CD62P were decreased in patients with chronic Chagas disease compared with those in uninfected subjects, with an inverse association with disease severity. Platelet activation in response to adenosine diphosphate was also decreased in T. cruzi-infected subjects. A major proportion of T. cruzi infected subjects showed increased serum levels of fibrinogen. Patients with severe cardiac dysfunction showed increased levels of endothelin-1 and normal values of procollagen I. In conclusion, chronic infection with T. cruzi induced hemostatic alterations, even in those patients who do not yet present cardiac symptoms.

Trypanosoma cruzi-Specific T-Cell Responses to Monitor Treatment Efficacy in Chronic Chagas Disease.

Chagas disease is the highest impact parasitic disease in Latin America. In recent years, the use of immune-related biomarkers to predict diagnostic and treatment efficacy or to monitor diseases has been considered a promising tool. Our group has worked for the past 20 years on the characterization of different immunological aspects of the T-cell responses to T. cruzi antigens. We have shown that monitoring of appropriate immunological responses can provide earlier and robust measures of treatment.The Enzyme-Linked ImmunoSPOT (ELISPOT) assays are powerful tools to evaluate antigen-specific immune responses at the single-cell level. Herein, we describe uses of the ELISPOT assay to determine the T. cruzi-specific T-cell populations in PBMCs from chronic chagasic subjects.

Correction: Trypanosoma cruzi-specific IFN-γ-producing cells in chronic Chagas disease associate with a functional IL-7/IL-7R axis.

[This corrects the article DOI: 10.1371/journal.pntd.0006998.].

Trypanosoma cruzi-specific IFN-γ-producing cells in chronic Chagas disease associate with a functional IL-7/IL-7R axis.

BACKGROUND: The severity of cardiac disease in chronic Chagas disease patients is associated with different features of T-cell exhaustion. Here, we assessed whether the ability of T cells to secrete IFN-γ in response to T. cruzi was linked to disruption in immune homeostasis and inflammation in patients with chronic Chagas disease. METHODOLOGY/PRINCIPAL FINDINGS: PBMCs from chronic Chagas disease patients and uninfected controls were examined for frequencies of T. cruzi-responsive IFN-γ-producing cells by ELISPOT and cellular expression and function of IL-7R using flow cytometry. Serum levels of IL-7, IL-21, IL-27, soluble IL-7R, and inflammatory cytokines were also evaluated by ELISA or CBA techniques. Patients possessing T. cruzi-specific IFN-γ-producing cells (i.e. IFN-γ producers) had higher levels of memory T cells capable of modulating the alpha chain of IL-7R and an efficient response to IL-7 compared to that in patients lacking (i.e. IFN-γ nonproducers) parasite-specific T-cell responses. IFN-γ producers also showed low levels of soluble IL-7R, high basal expression of Bcl-2 in T cells and low basal frequencies of activated CD25+ T cells. Modulation of IL-7R was inversely associated with serum IL-6 levels and positively associated with serum IL-8 levels. Circulating IL-21 and IL-27 levels were not associated with the frequency of IFN-γ producing cells but were reduced in less severe clinical forms of the disease. In vitro stimulation of PBMCs with IL-7 or IL-27 enhanced IFN-γ production in IFN-γ producers but not in IFN-γ nonproducers. CONCLUSIONS/SIGNIFICANCE: Alterations of the IL-7/IL-7R axis and in the levels of inflammatory cytokines were linked to impaired T. cruzi-specific IFN-γ production. These alterations might be responsible of the process of immune exhaustion observed in chronic Chagas disease.

Distinct monocyte subset phenotypes in patients with different clinical forms of chronic Chagas disease and seronegative dilated cardiomyopathy.

BACKGROUND: Chronic infection with Trypanosoma cruzi leads to a constant stimulation of the host immune system. Monocytes, which are recruited in response to inflammatory signals, are divided into classical CD14hiCD16-, non-classical CD14loCD16+ and intermediate CD14hiCD16+ subsets. In this study, we evaluated the frequencies of monocyte subsets in the different clinical stages of chronic Chagas disease in comparison with the monocyte profile of seronegative heart failure subjects and seronegative healthy controls. The effect of the anti-parasite drug therapy benznidazole on monocyte subsets was also explored. METHODOLOGY/PRINCIPAL FINDINGS: The frequencies of the different monocyte subsets and their phenotypes were measured by flow cytometry. Trypanosoma cruzi-specific antibodies were quantified by conventional serological tests. T. cruzi-infected subjects with mild or no signs of cardiac disease and patients suffering from dilated cardiomyopathy unrelated to T. cruzi infection showed increased levels of non-classical CD14loCD16+ monocytes compared with healthy controls. In contrast, the monocyte profile in T. cruzi-infected subjects with severe cardiomyopathy was skewed towards the classical and intermediate subsets. After benznidazole treatment, non-classical monocytes CD14loCD16+ decreased while classical monocytes CD14hiCD16-increased. CONCLUSIONS/SIGNIFICANCE: The different clinical stages of chronic Chagas disease display distinct monocyte profiles that are restored after anti-parasite drug therapy. T. cruzi-infected subjects with severe cardiac disease displayed a profile of monocytes subsets suggestive of a more pronounced inflammatory environment compared with subjects suffering from heart failure not related to T. cruzi infection, supporting that parasite persistence might also alter cell components of the innate immune system.

New Fixed-Dose Combinations of Fenofibrate/Simvastatin Therapy Significantly Improve the Lipid Profile of High-Risk Patients with Mixed Dyslipidemia Versus Monotherapies.

AIMS: Guidelines propose additional therapy to statin to treat elevated triglycerides (TG) and low high-density lipoprotein cholesterol (HDLC) in dyslipidemic patients. We evaluated the effects of new fixed-dose combinations (FDC) of fenofibrate/simvastatin on plasma lipids versus simvastatin or fenofibrate monotherapies. METHODS: Subjects with mixed dyslipidemia at high or very high cardiovascular risk on stable statin therapy for at least 3 months were included in a randomized, double-blind, active-control, parallel-group study. Patients were treated with FDC fenofibrate/simvastatin 145/20 mg or 145/40 mg, simvastatin 20 mg or 40 mg, or fenofibrate 145 mg for 12 weeks. Plasma lipids, C-reactive protein, and cystatin C were measured before and after treatments. Differences in % changes were compared between FDC fenofibrate/simvastatin and monotherapies. RESULTS: Significant differences between FDC fenofibrate/simvastatin and simvastatin monotherapies were observed for the % change of TG (LS mean difference [two-sided 95% CI]: -32.2% [-38.6%, -25.8%], P < 0.001) and HDL-C (7.5% [4.7%, 10.2%], P < 0.001). A significant difference between the FDC fenofibrate/simvastatin and fenofibrate was observed for LDLC % changes (-34.7% [-40.8%, -28.5%], P < 0.001). Significant differences between FDC fenofibrate/simvastatin and their respective monotherapies were also observed for Apo B and non-HDLC % changes. The FDC were well tolerated with a similar safety profile compared with monotherapies. CONCLUSIONS: FDC fenofibrate/simvastatin are effective and well-tolerated therapies to improve the TG and HDLC profile in high-risk patients with mixed dyslipidemia.

Foot-and-mouth disease virus infection of dendritic cells triggers phosphorylation of ERK1/2 inducing class I presentation and apoptosis.

Foot-and-mouth disease (FMD) is a highly contagious viral disease of cloven-hoofed animals. This pathology is caused by foot-and-mouth disease virus (FMDV). Over time, the development of vaccines to prevent the spread of this illness became essential. Vaccines currently used contain the inactivated form of the virus. However, vaccination generates an immune response different to that induced by the infection. We investigated whether these differences are related to intracellular mechanisms on dendritic cells (DCs). As a result, we demonstrated that the internalization of infective virus triggered the phosphorylation of ERK1/2, which was involved in the activation of caspase-9, the intrinsic pathway of apoptosis and the delivery of viral peptides on MHC class I molecules. While, inactivated virus (iFMDV) did not affect this pathway or any function mediated by its activation. As described, infectious virus in DCs was also associated to autophagy LC3 protein and was associated to lysosomal protein Lamp-2; contrary to observe for the iFMDV. Strikingly, the processing of viral antigens to accommodate in class I molecules does not appear to involve the proteasome. Finally, this increased presentation promotes a specific cytotoxic response against infectious virus.

Prevalencia de hipomagnesemia en pacientes con insuficiencia cardiaca tratados con diuréticos / Hypomagnesemia prevalence in diuretic-treated patients with cardiac failure

Antecedentes. El magnesio participa en numerosas reacciones enzimáticas vitales para el organismo. Objetivo. Identificar la prevalencia de hipomagnesemia (Mg < 1.6 mg/dl), sus características clínicas y su relación con el tratamiento diurético. Material y métodos. Se evaluaron 43 pacientes adultos con diagnóstico de insuficiencia cardiaca congestiva (ICC), clase funcional I-IV, sin daño renal, que recibieran el mismo tratamiento en las cuatro semanas previas al estudio. Se midieron las concentraciones de magnesio, sodio, potasio y calcio. Se registró el tratamiento diurético que estaba recibiendo cada paciente. Resultados. Tuvieron hipomagnesemia siete pacientes (16.2 por ciento) (Mg 1.5 ñ 0.07), los restantes 36 (83.8 por ciento) fueron normales (Mg 2.1 ñ 0.58). Las manifestaciones clínicas no fueron estadísticamente diferentes en ambos grupos. Las concentraciones de potasio y calcio fueron menores en el grupo de hipomagnesemia que en el de magnesio normal. Cuando se utilizó furosemida la concentración de magnesio fue menor en ambos grupos. Conclusiones. En pacientes con insuficiencia cardiaca congestiva la hipomagnesemia es un trastorno común que debería investigarse con más frecuencia por los clínicos debido al riesgo potencial de complicaciones del ritmo cardiaco