Trypanosoma cruzi parasites are only rarely identified in conventional histological sections of hearts from chronic chagasic patients. This finding suggests that T. cruzi plays no important direct role in the chronic myocarditis that accordingly has been considered mainly an autoimmune process. We reinvestigated this issue using a polyclonal anti-T. cruzi antibody serum to map immunohistochemically the T. cruzi antigen(s) in 9 different regions of 8 necropsy hearts and 24 septal fragments from 24 hearts from chronic chagasic patients. T. cruzi antigen(s) were identified in 7 (87%) of the 8 mapped hearts and in 14 (58%) of the 24 septal fragments. There was a statistically significant correlation between the presence of T. cruzi antigen(s) and moderate or severe inflammatory infiltrate (p = 0.005). When staining revealed amastigotes within intact myocardial fibers, there was no surrounding inflammatory infiltrate. However, when T. cruzi antigen(s) were found in macrophages either as amastigotes, diffusely in the macrophages cytoplasm, or free in the interstitium as round structures similar to amastigotes, there was a heavy inflammatory infiltrate. In the case in which no parasite was detected, a mild inflammatory infiltrate was present in the myocardium. Foci of fibrosis did not stain for T. cruzi antigen. These findings do not exclude a role of autoimmunity in chronic chagasic cardiopathy. However, the striking correlation between the presence of T. cruzi antigen(s) with the severity of site of the inflammatory infiltrate supports a direct role for the parasite in the perpetuation of myocardial inflammation in Chagas' disease. The destruction of microvessels and occasional endothelial cells with parasitism among dense inflammatory infiltrate favors the concept that microcirculatory injury, induced by T. cruzi, also contributes to the lesions of chronic Chagas' disease.

Download full-text PDF

Source
http://dx.doi.org/10.1016/1054-8807(93)90021-SDOI Listing

Publication Analysis

Top Keywords

inflammatory infiltrate
28
cruzi antigens
20
chronic chagasic
16
cruzi
11
trypanosoma cruzi
8
hearts chronic
8
chagasic patients
8
direct role
8
septal fragments
8
correlation presence
8

Similar Publications

A high-resolution view of the immune and stromal cell response to infection in human volunteers.

mBio

January 2025

Department of Medical and Molecular Genetics and Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, Indiana, USA.

causes the genital ulcer disease chancroid and cutaneous ulcers in children. To study its pathogenesis, we developed a human challenge model in which we infect the skin on the upper arm of human volunteers with to the pustular stage of disease. The model has been used to define lesional architecture, describe the immune infiltrate into the infected sites using flow cytometry, and explore the molecular basis of the immune response using bulk RNA-seq.

View Article and Find Full Text PDF

Ischemia-reperfusion injury (IRI) is a major obstacle in liver transplantation, especially with steatotic donor livers. Dysbiosis of the gut microbiota has been implicated in modulating IRI, and plays a pivotal role in regulating host inflammatory and immune responses, but its specific role in liver transplantation IRI remains unclear. This study explores whether can mitigate IRI and its underlying mechanisms.

View Article and Find Full Text PDF

Insufficient radio-frequency ablation (IRFA) of hepatocellular carcinoma accelerates the recurrence of residual tumor, leading to a poor prognosis. Neutrophils (NEs), as the initial leukocytes to infiltrate the IRFA-associated inflammatory area, were utilized as drug carriers due to their inherent chemotactic properties for targeted delivery of chemotherapy drugs to the inflammatory site where residual tumor persists post-IRFA. Previous research has highlighted that the immunosuppressive cytokines in the tumor microenvironment could promote the transition of NEs into a protumorigenic phenotype.

View Article and Find Full Text PDF

Intracerebral hemorrhage (ICH) is the most common subtype of hemorrhagic stroke causing significant morbidity and mortality. Previously clinical treatments for ICH have largely been based on a single pathophysiological perspective, and there remains a lack of curative interventions. Following the rupture of cerebral blood vessels, blood metabolites activate resident immune cells such as microglia and astrocytes, and infiltrate peripheral immune cells, leading to the release of a series of inflammatory mediators.

View Article and Find Full Text PDF

Introduction: Interleukin-10 (IL-10) is a potent immunomodulatory cytokine widely explored as a therapeutic agent for diseases, including myocardial infarction (MI). High-dose IL-10 treatment may not achieve expected outcomes, raising the question of whether IL-10 has dose-dependency, or even uncharted side-effects from overdosing. We hypothesized that IL-10 has dose-dependent effects on macrophage (Mφ) phenotypic transition and cardiac remodeling after MI.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!