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: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:Background: Outcomes in patients with severe SARS-CoV-2 infection (COVID-19) are conditioned by viral control and regulation of inflammation. Variants in IFIH1, a gene coding the cytoplasmatic RNA sensor MDA5, regulate the response to viral infections. Methods: Patients admitted to an intensive care unit (ICU) with documented COVID-19 were prospectively included and IFIH1 rs1990760 genotypes determined. Peripheral blood gene expression, cell populations and immune mediators were measured during the first day after ICU admission before steroid therapy. Peripheral blood mononuclear cells from healthy volunteers were exposed ex-vivo to an MDA5 agonist and dexamethasone, and changes in gene expression assessed. ICU discharge and hospital death were modelled using rs1990760 variants and dexamethasone therapy as factors. Findings: 237 patients were studied. Patients with the IFIH1 rs1990760 TT variant showed a decrease in expression of inflammation-related pathways, an anti-inflammatory cell profile and a decrease in pro-inflammatory mediators. Cells with TT variant exposed to an MDA5 agonist ex-vivo showed an increase in FOXO3 and IL6 when dexamethasone was added. All patients with the TT variant not treated with steroids (n=14) survived their ICU stay (HR 2.49 95% confidence interval 1.29 – 4.79). Dexamethasone therapy in this subgroup (N=50) delayed ICU discharge and increased hospital mortality (HR 2.19, 95% confidence interval 1.01 – 4.87) and serum IL-6 concentrations. Interpretation: COVID-19 ICU patients with the IFIH1 rs1990760 TT variant show an ameliorated inflammatory response that results in better outcomes than CC/CT variants. Dexamethasone can reverse this anti-inflammatory phenotype, worsening the outcome. Funding: Instituto de Salud Carlos III.
Project description:In this study, we aim to evaluate the relation between COVID-19 and bacterial secondary superinfections. We assessed the functional responses of neutrophils and monocytes isolated from acute and recovery COVID-19 patients upon bacterial infection using Flow-cytometry and proteomics based assays. Both neutrophils and monocytes showed impared intracellular microbicidal capacity along with a decreased functional response. Determination of plasma cytokines levels showed a significant association of certain cytokines towards secondary bacterial infection.
Project description:BackgroundMicrovascular, arterial and venous thrombotic events have been largely described during severe coronavirus disease 19 (COVID-19). However, mechanisms underlying hemostasis dysregulation remain unclear.MethodsWe explored two independent cross-sectional cohorts to identify soluble markers and gene-expression signatures that discriminated COVID-19 severity and outcomes.ResultsWe found that elevated soluble (s)P-selectin at admission was associated with disease severity. Elevated sP-selectin was predictive of intubation and death (ROC AUC = 0.67, p = 0.028 and AUC = 0.74, p = 0.0047, respectively). An optimal cutoff value was predictive of intubation with 66% negative predictive value (NPV) and 61% positive predictive value (PPV), and of death with 90% NPV and 55% PPV. An unbiased gene set enrichment analysis revealed that critically ill patients had increased expression of genes related to platelet activation. Hierarchical clustering identified ITG2AB, GP1BB, PPBP and SELPLG to be upregulated in a grade-dependent manner. ROC curve analysis for the prediction of intubation was significant for SELPLG and PPBP (AUC = 0.8, p = 0.046 for both). An optimal cutoff value for PBPP was predictive of intubation with 100% NPV and 45% PPV, and for SELPLG with 100% NPV and 50% PPV.ConclusionWe provide evidence that platelets contribute to COVID-19 severity. Plasma sP-selectin level was associated with severity and in-hospital mortality. Transcriptional analysis identified PPBP/CXCL7 and SELPLG as biomarkers for intubation. These findings provide additional evidence for platelet activation in driving critical COVID-19. Specific studies evaluating the performance of these biomarkers are required.
Project description:BackgroundCritically ill coronavirus disease 2019 (COVID-19) patients present with a hypercoagulable state with high rates of macrovascular and microvascular thrombosis, for which hypofibrinolysis might be an important contributing factor.MethodsWe retrospectively analysed 20 critically ill COVID-19 patients at Innsbruck Medical University Hospital whose coagulation function was tested with ClotPro® and compared with that of 60 healthy individuals at Augsburg University Clinic. ClotPro is a viscoelastic whole blood coagulation testing device. It includes the TPA test, which uses tissue factor (TF)-activated whole blood with added recombinant tissue-derived plasminogen activator (r-tPA) to induce fibrinolysis. For this purpose, the lysis time (LT) is measured as the time from when maximum clot firmness (MCF) is reached until MCF falls by 50%. We compared COVID-19 patients with prolonged LT in the TPA test and those with normal LT.ResultsCritically ill COVID-19 patients showed hypercoagulability in ClotPro assays. MCF was higher in the EX test (TF-activated assay), IN test (ellagic acid-activated assay), and FIB test (functional fibrinogen assay) with decreased maximum lysis (ML) in the EX test (hypofibrinolysis) and highly prolonged TPA test LT (decreased fibrinolytic response), as compared with healthy persons. COVID-19 patients with decreased fibrinolytic response showed higher fibrinogen levels, higher thrombocyte count, higher C-reactive protein levels, and decreased ML in the EX test and IN test.ConclusionCritically ill COVID-19 patients have impaired fibrinolysis. This hypofibrinolytic state could be at least partially dependent on a decreased fibrinolytic response.
Project description:BackgroundSevere coronavirus disease-2019 (COVID-19) can progress to an acute respiratory distress syndrome (ARDS), which involves alveolar infiltration by activated neutrophils. The beta-blocker metoprolol has been shown to ameliorate exacerbated inflammation in the myocardial infarction setting.ObjectivesThe purpose of this study was to evaluate the effects of metoprolol on alveolar inflammation and on respiratory function in patients with COVID-19-associated ARDS.MethodsA total of 20 COVID-19 patients with ARDS on invasive mechanical ventilation were randomized to metoprolol (15 mg daily for 3 days) or control (no treatment). All patients underwent bronchoalveolar lavage (BAL) before and after metoprolol/control. The safety of metoprolol administration was evaluated by invasive hemodynamic and electrocardiogram monitoring and echocardiography.ResultsMetoprolol administration was without side effects. At baseline, neutrophil content in BAL did not differ between groups. Conversely, patients randomized to metoprolol had significantly fewer neutrophils in BAL on day 4 (median: 14.3 neutrophils/µl [Q1, Q3: 4.63, 265 neutrophils/µl] vs median: 397 neutrophils/µl [Q1, Q3: 222, 1,346 neutrophils/µl] in the metoprolol and control groups, respectively; P = 0.016). Metoprolol also reduced neutrophil extracellular traps content and other markers of lung inflammation. Oxygenation (PaO2:FiO2) significantly improved after 3 days of metoprolol treatment (median: 130 [Q1, Q3: 110, 162] vs median: 267 [Q1, Q3: 199, 298] at baseline and day 4, respectively; P = 0.003), whereas it remained unchanged in control subjects. Metoprolol-treated patients spent fewer days on invasive mechanical ventilation than those in the control group (15.5 ± 7.6 vs 21.9 ± 12.6 days; P = 0.17).ConclusionsIn this pilot trial, intravenous metoprolol administration to patients with COVID-19-associated ARDS was safe, reduced exacerbated lung inflammation, and improved oxygenation. Repurposing metoprolol for COVID-19-associated ARDS appears to be a safe and inexpensive strategy that can alleviate the burden of the COVID-19 pandemic.