Project description:Precise reasons for severe manifestation of SARS-CoV-2 remain unanswered, and efforts have been focused on respiratory system management. Demonstration of unequivocal presence of SARS-CoV-2 in vital body organs by cadaver autopsy was the only way to prove multi-organ involvement. Hence, the primary objective of the study was to determine presence of the SARS-CoV-2 in various organs of patients succumbing to SARS-CoV-2 infection. A total of 246 samples from different organs of 21 patients who died due to severe COVID-19 illness were investigated by qRT-PCR, and SARS-CoV-2 was detected in 181 (73.57%) samples and highest positivity of SARS-CoV-2 being (expectedly) found in nasopharynx (90.4%) followed by bilateral lungs (87.30%), peritoneal fluid (80%), pancreas (72.72%), bilateral kidneys (68.42%), liver (65%) and even in brain (47.2%). The deceased patients were categorized to three subgroups based upon the extent of organs in which SARS-CoV-2 was detected by qRT-PCR (high intensity ≥80%, intermediate intensity = 65–80% and low intensity ≤65% organs involvement). It was conclusively established that SARS-CoV-2 has the property of invasion beyond lungs and even crosses the blood–brain barrier, resulting in multi-system disease; this is probably the reason behind cytokine storm, though it is not clear whether organ damage is due to direct injury caused by the virus or result of inflammatory assault. Significant inverse correlation was found between the Ct value of lung samples and number of organs involved, implying that higher viral load in lungs is directly proportionate to involvement of extrapulmonary organs and patients with higher viral load in respiratory secretions should be monitored more closely for any warning signs and the treatment strategies should also address involvement of other organs for better outcome, because lungs, though the primary site of infection, are not the only organ system responsible for pathogenesis of systemic illness.
Project description:BackgroundDespite the expanding literature that discusses insights into the clinical picture and mechanisms by which the SARS-CoV-2 virus invades the nervous system, data on the neuropathologic findings of patients who died following SARS-CoV-2 infection is limited.MethodsA broad literature search was done for published articles that reported on histopathological findings of the brain in patients with COVID-19 in PubMed by MEDLINE, Embase, CENTRAL by the Cochrane Library, and SCOPUS from December 31, 2019 to October 31, 2020.ResultsThe systematic literature search strategy used resulted in a total of 1608 articles of which 14 were included in the analysis (PROSPERO registration number: CRD42020221022). There were ten case series, two case reports, one retrospective cohort, and one prospective cohort. The age of the patients ranged between 38 and 90 years old, most of them older than 65 years old (n=66, 45.2%) and males (n=79, 54.1%). Most tested negative in SARS-CoV-2 immunohistochemistry (n=70, 47.9%). The striking pathologic changes included diffuse edema (n=25, 17.1%), gliosis with diffuse activation of microglia and astrocytes (n=52, 35.6%), infarctions involving cortical and subcortical areas of the brain (n=4, 2.7%), intracranial bleed (subarachnoid hemorrhage and punctate hemorrhages) (n=18, 12.4%), arteriosclerosis (n=43, 29.5%), hypoxic-ischemic injury (n=41, 28.1%), and signs of inflammation (n=52, 35.6%). The cause of death was attributed to the cardiorespiratory system (n=66, 45.2%).ConclusionsThe neuropathologic changes observed likely represent direct cytopathic effects and indirect effects secondary to host-specific inflammatory response induced by the viral infection. Further studies however are required to better elucidate the pathologic mechanism.
Project description:Mounting clinical evidence indicates severe pathological consequences from COVID-19 in the heart. Here we examine cardiac susceptibility and response to SARS-CoV-2 using human induced pluripotent stem cell-derived cardiomyocytes, cardiac fibroblasts, and endothelial cells. Of these cell types, SARS-CoV-2 can only productively infect cardiomyocytes, and does so via an endolysosomal mechanism. Transcriptomic profiling of infected cells revealed changes in protein homeostasis and cardiomyocyte contractility, and activation of innate immune response pathways. In addition, we observed a striking pattern of myofibrillar fragmentation, with specific cleavage at the M-line. Numerous cardiomyocytes also lacked nuclear DNA in tissue culture experiments and COVID-19 autopsy specimens. These novel cardiac pathologies induced by SARS-CoV-2 strongly motivate the development of targeted cardioprotective strategies to prevent acute and long-term heart failure in COVID-19 patients.
Project description:Dexamethasone improves the survival of COVID-19 patients in need of supplemental oxygen therapy. Hospitalized COVID-19 patients eligible for dexamethasone therapy were recruited from the general care ward in several centers in Greece and the Netherlands and whole blood transcriptomic analysis was performed before and after starting dexamethasone treatment. Peripheral blood mononuclear cells (PBMCs) were isolated from healthy individuals and COVID-19 patients and stimulated with inactivated SARS-CoV-2 ex vivo in the presence or absence of dexamethasone and their transcriptome was assessed.
Project description:The molecular properties of CD8+ T cells that respond to SARS-CoV-2 infection are not fully known. Here, we report on the single-cell transcriptomes of >80,000 virus-reactive CD8+ T cells, obtained using a modified Antigen-Reactive T cell Enrichment (ARTE) assay, from 39 COVID-19 patients and 10 healthy subjects. COVID-19 patients segregated into two groups based on whether the dominant CD8+ T cell response to SARS-CoV-2 was ‘exhausted’ or not. SARS-CoV-2-reactive cells in the exhausted subset were increased in frequency and displayed lesser cytotoxicity and inflammatory features in COVID-19 patients with mild compared to severe illness. In contrast, SARS-CoV-2-reactive cells in the dominant non-exhausted subset from patients with severe disease showed enrichment of transcripts linked to co-stimulation, pro-survival NF-κB signaling, and anti-apoptotic pathways, suggesting the generation of robust CD8+ T cell memory responses in patients with severe COVID-19 illness. CD8+ T cells reactive to influenza and respiratory syncytial virus from healthy subjects displayed polyfunctional features and enhanced glycolysis. Cells with such features were largely absent in SARS-CoV-2-reactive cells from both COVID-19 patients and healthy controls non-exposed to SARS-CoV-2. Overall, our single-cell analysis revealed substantial diversity in the nature of CD8+ T cells responding to SARS-CoV-2.