Distinct Microbial Communities in Dilated Cardiomyopathy Explanted Hearts Are Associated With Different Myocardial Rejection Outcomes.

Background: Idiopathic dilated cardiomyopathy (IDCM) myocardial inflammation may be associated with external triggering factors such as infectious agents. Here, we searched if moderate/severe heart transplantation rejection is related to the presence of myocardial inflammation in IDCM explanted hearts, associated with microbial communities. Method: Receptor myocardial samples from 18 explanted hearts were separated into groups according to post-transplant outcome: persistent moderate rejection (PMR; n = 6), moderate rejection (MR; n = 7) that regressed after pulse therapy, and no rejection (NR; n = 5)/light intensity rejection. Inflammation was quantified through immunohistochemistry (IHC), and infectious agents were evaluated by IHC, molecular biology, in situ hybridization technique, and transmission electron microscopy (TEM). Results: NR presented lower numbers of macrophages, as well as B cells (p = 0.0001), and higher HLA class II expression (p ≤ 0.0001). PMR and MR showed higher levels of Mycoplasma pneumoniae (p = 0.003) and hepatitis B core (p = 0.0009) antigens. NR presented higher levels of parvovirus B19 (PVB19) and human herpes virus 6 (HHV6) and a positive correlation between Borrelia burgdorferi (Bb) and enterovirus genes. Molecular biology demonstrated the presence of M. pneumoniae, Bb, HHV6, and PVB19 genes in all studied groups. TEM revealed structures compatible with the cited microorganisms. Conclusions: This initial study investigating on infectious agents and inflammation in the IDCM explanted hearts showed that the association between M. pneumoniae and hepatitis B core was associated with a worse outcome after HT, represented by MR and PMR, suggesting that different IDCM microbial communities may be contributing to post-transplant myocardial rejection.

Morphomolecular Characterization of Serum Nanovesicles From Microbiomes Differentiates Stable and Infarcted Atherosclerotic Patients.

Microbial communities are considered decisive for maintaining a healthy situation or for determining diseases. Acute myocardial infarction (AMI) is an important complication of atherosclerosis caused by the rupture of atheroma plaques containing proinflammatory cytokines, reactive oxygen species, oxidized low-density lipoproteins (oxLDL), damaged proteins, lipids, and DNA, a microenvironment compatible with a pathogenic microbial community. Previously, we found that archaeal DNA-positive infectious microvesicles (iMVs) were detected in vulnerable plaques and in the sera of Chagas disease patients with heart failure. Now, we characterize and quantify the levels of serum microbiome extracellular vesicles through their size and content using morphomolecular techniques to differentiate clinical outcomes in coronary artery disease (CAD). We detected increased numbers of large iMVs (0.8-1.34 nm) with highly negative surface charge that were positive for archaeal DNA, Mycoplasma pneumoniae antigens and MMP9 in the sera of severe AMI patients, strongly favoring our hypothesis that pathogenic archaea may play a role in the worst outcomes of atherosclerosis. The highest numbers of EVs <100 nm (exosomes) and MVs from 100 to 200 nm in the stable atherosclerotic and control healthy groups compared with the AMI groups were indicative that these EVs are protective, entrapping and degrading infectious antigens and active MMP9 and protect against the development of plaque rupture. Conclusion: A microbiome with pathogenic archaea is associated with high numbers of serum iMVs in AMI with the worst prognosis. This pioneering work demonstrates that the morphomolecular characterization and quantification of iEVs in serum may constitute a promising serum prognostic biomarker in CAD.

Patogênese da Doença de Chagas na era atual - microrganismos e micropartículas / The present-day pathogenesis of Chagas Disease - microorganisms and microparticles

A presente revisão descreve os principais achados anatomopatológicos que caracterizam a cardiopatia chagásica crônica, discute a teoria autoimune e parassimpaticopriva que dominaram a explicação patogenética nas ultimas décadas e propõe novos caminhos a partir de achados mais recentes. Esses achados se relacionam com a presença de outros microrganismos que talvez tenham sejam levados até o miocárdio por estarem em simbiose com o T. cruzi, como micoplasmas, clamídias e arqueias. As arqueias têm como característica aumentar a inflamação por apresentarem antígenos aos linfócitos T CD8+. A inflamação exacerbada pode levar à vasodilatação da microcirculação e à falha na distribuição de sangue no miocárdio, ocasionando áreas de isquemia em regiões distais de dupla irrigação. Isto explicaria as regiões de afilamento e dilatação aneurismática ventricular, bem como a fibrose e infiltração gordurosa do sistema de condução (feixe de His, nó sinoatrial e atrioventricular). Esses microrganismos no interior da fibra cardíaca podem induzir uma resposta imunológica com fibrose ao redor dos cardiomiócitos, os quais se tornam extremamente hipertróficos por não entrarem em apoptose. A simbiose entre esses microrganismos pode levar à produção de micropartículas infecciosas que circulam e fazem parte da patogenia da descompensação cardíaca. Assim, a ação terapêutica na doença de Chagas deveria incluir a eliminação simultânea desses diferentes microrganismos e não somente do T. cruzi

This review describes the main anatomopathological findings that characterize chronic Chagasic cardiomyopathy, discusses the autoimmune and parasympathetic dysautonomia theories that have dominated the pathogenic explanation in recent decades, and proposes new routes based on the most recent findings. These findings relate to the presence of other microorganisms, such as micoplasmas, chlamydias and archaea, that are perhaps carried to the myocardium as they are in symbiosis with T. cruzi. A characteristic of archaea is that they increase inflammation by presenting T CD8+ lymphocyte antigens. Exacerbated inflammation may lead to vasodilation of the microcirculation and failure of blood distribution in the myocardium, leading to areas of ischemia in distal regions of double irrigation. This would explain the regions of thinning and dilation of the ventricular aneurysm, as well as the fibrosis and fatty infiltration of the conduction system (His bundle, sinoatrial node and atrioventricular node). These microorganisms in the interior of the heart fiber may lead to an immunological response with fibrosis around the cardiomyocytes, which become extremely hypertrophic, as they do not enter apoptosis. The symbiosis between these microorganisms can lead to the production of infectious microparticles that circulate and form part of the pathogenesis of decompensated heart failure. The therapeutic conduct in Chagas disease should therefore include the simultaneous elimination of these different microorganisms, and not only of T. cruzi

Infectious agents and inflammation in donated hearts and dilated cardiomyopathies related to cardiovascular diseases, Chagas' heart disease, primary and secondary dilated cardiomyopathies.

BACKGROUND: Clinical and experimental conflicting data have questioned the relationship between infectious agents, inflammation and dilated cardiomyopathy (DCM). OBJECTIVES: The aim of this study was to determine the frequency of infectious agents and inflammation in endomyocardial biopsy (EMB) specimens from patients with idiopathic DCM, explanted hearts from different etiologies, including Chagas' disease, compared to donated hearts. METHODS: From 2008 to 2011, myocardial samples from 29 heart donors and 55 patients with DCMs from different etiologies were studied (32 idiopathic, 9 chagasic, 6 ischemic and 8 other specific etiologies). Inflammation was investigated by immunohistochemistry and infectious agents by immunohistochemistry, molecular biology, in situ hybridization and electron microscopy. RESULTS: There were no differences regarding the presence of macrophages, expression of HLA class II and ICAM-I in donors and DCM. Inflammation in Chagas' disease was predominant. By immunohistochemistry, in donors, there was a higher expression of antigens of enterovirus and Borrelia, hepatitis B and C in DCMs. By molecular biology, in all groups, the positivity was elevated to microorganisms, including co-infections, with a higher positivity to adenovirus and HHV6 in donors towards DCMs. This study was the first to demonstrate the presence of virus in the heart tissue of chagasic DCM. CONCLUSIONS: The presence of inflammation and infectious agents is frequent in donated hearts, in the myocardium of patients with idiopathic DCM, myocardial dysfunction related to cardiovascular diseases, and primary and secondary cardiomyopathies, including Chagas' disease. The role of co-infection in Chagas' heart disease physiopathology deserves to be investigated in future studies.