Project description:Infections caused by SARS-CoV-2 may cause a severe disease, termed COVID-19, with significant mortality. Host responses to this infection, mainly in terms of systemic inflammation, have emerged as key pathogenetic mechanisms, and their modulation is the only therapeutic strategy that has shown a mortality benefit. Herein, we used peripheral blood transcriptomes of critically-ill COVID-19 patients obtained at admission in an Intensive Care Unit, to identify two clusters that, in spite of no major clinical differences, have different gene expression profiles that reveal different underlying pathogenetic mechanisms and ultimately have different ICU outcome. A transcriptomic signature was used to identify these clusters in an external validation cohort, yielding a similar result. These results illustrate the potential of transcriptomic profiles to identify patient endotypes and point to relevant pathogenetic mechanisms in COVID-19.
Project description:Infections caused by SARS-CoV-2 may cause a severe disease, termed COVID-19, with significant mortality. Host responses to this infection, mainly in terms of systemic inflammation, have emerged as key pathogenetic mechanisms, and their modulation is the only therapeutic strategy that has shown a mortality benefit. Herein, we used peripheral blood transcriptomes of critically-ill COVID-19 patients obtained at admission in an Intensive Care Unit, to identify two clusters that, in spite of no major clinical differences, have different gene expression profiles that reveal different underlying pathogenetic mechanisms and ultimately have different ICU outcome. A transcriptomic signature was used to identify these clusters in an external validation cohort, yielding a similar result. These results illustrate the potential of transcriptomic profiles to identify patient endotypes and point to relevant pathogenetic mechanisms in COVID-19.
Project description:Infections caused by SARS-CoV-2 may cause a severe disease, termed COVID-19, with significant mortality. Host responses to this infection, mainly in terms of systemic inflammation, have emerged as key pathogenetic mechanisms, and their modulation is the only therapeutic strategy that has shown a mortality benefit. Herein, we used peripheral blood transcriptomes of critically-ill COVID-19 patients obtained at admission in an Intensive Care Unit, to identify two clusters that, in spite of no major clinical differences, have different gene expression profiles that reveal different underlying pathogenetic mechanisms and ultimately have different ICU outcome. A transcriptomic signature was used to identify these clusters in an external validation cohort, yielding a similar result. These results illustrate the potential of transcriptomic profiles to identify patient endotypes and point to relevant pathogenetic mechanisms in COVID-19.
Project description:Peripheral blood gene expression analysis of IFIH1 rs1990760 variants in critically-ill COVID-19 patients with and without corticosteroids treatment
Project description:There remains an urgent need to delinate immune cell states that contribute to mortality in critially ill COVID-19 patients. To better understand determinants of mortality, we performed high dimensional profiling of blood and respiratory samples from critially ill COVID-19 patients. Single-cell RNAseq based characterization of peripheral immune states reveal distinct expression profiles that were predictive of COVID-19 mortality. Temporal analysis revealed a that persistently elevated levels of inflammatory monocyte signatures and persistent interferon signaling preceeded concerted upregulation of inflammatory cytokines. Interrogation of lower respiratory tract saples revelaed that infected myeliod cells upregulated CXCL10, and elevated levels of CXCL10 in plasma were associated with a high risk of death. Overall, our data suggest a pivotal role for myeloid cell states in severe COVID-19 and may faciliate discovery of new diagnostics and therapeutics.
Project description:Single-cell RNA-sequencing reveals a shift from focused IFN alpha-driven signals in COVID-19 ICU patients who survive to broad pro-inflammatory responses in fatal COVID-19 – a feature not observed in severe influenza. We conclude that fatal COVID-19 infection is driven by uncoordinated inflammatory responses that drive a hierarchy of T cell activation, elements of which can serve as prognostic indicators and potential targets for immune intervention.
Project description:It is known that about 60% of all human messenger RNAs (mRNAs) regulated by microRNAs, the role of mRNAs and microRNAs in the critically ill patients with Coronavirus Infection 2019 (COVID-19) is unknown. To evaluate mRNA and microRNA in whole blood of the critically ill patients with COVID-19 and to elucidate the pathogenesis of COVID-19 including the subsequent proteins profile following mRNA and microRNA integration analysis. RNA was extracted from the whole blood in 5 healthy controls and 10 critically ill patients with COVID-19 at the time of admission. mRNA and miRNA were measured by RNA sequence, and gene expression variation and pathway analysis were performed. As the IFNs proteins profile cohort, IFN-α2, IFN-β, IFN-γ, IL-27 and IFN-λ1 were measured on the day of admission (day 1, 181 critical and 22 non-critical patients) and day 6-8 (168 critical patients) in COVID19 patients and 19 healthy controls. Compared to healthy controls, 3488 mRNA and 31 miRNA genes were identified in the differentially expressed genes in the critically ill patients with COVID-19 (p-value<0.05, Log 2 fold change> |2|). In the canonical pathway analysis using Ingenuity Pathway Analysis (IPA), interferon signaling pathway was the most activated. In plasma interferon levels, IFN-β was elevated along with the increase of severity compared to healthy controls. IFN-λ1 was elevated in moderate disease compared to healthy controls, and conversely, IFN-λ1 was lower in severe disease than in moderate disease. Integration of mRNA and microRNA analysis showed activated interferon signaling. The plasma interferon proteins profile revealed that IFN-β (type I) and IFN-λ1 (type III) played an important role in the disease progression of COVID-19.