Respiratory failure in the acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic is hypothesized to be driven by an overreacting innate immune response, where the complement system is a key ...player. In this prospective cohort study of 39 hospitalized coronavirus disease COVID-19 patients, we describe systemic complement activation and its association with development of respiratory failure. Clinical data and biological samples were obtained at admission, days 3 to 5, and days 7 to 10. Respiratory failure was defined as PO₂/FiO₂ ratio of ≤40 kPa. Complement activation products covering the classical/lectin (C4d), alternative (C3bBbP) and common pathway (C3bc, C5a, and sC5b-9), the lectin pathway recognition molecule MBL, and antibody serology were analyzed by enzyme-immunoassays; viral load by PCR. Controls comprised healthy blood donors. Consistently increased systemic complement activation was observed in the majority of COVID-19 patients during hospital stay. At admission, sC5b-9 and C4d were significantly higher in patients with than without respiratory failure (P = 0.008 and P = 0.034). Logistic regression showed increasing odds of respiratory failure with sC5b-9 (odds ratio 31.9, 95% CI 1.4 to 746, P = 0.03) and need for oxygen therapy with C4d (11.7, 1.1 to 130, P = 0.045). Admission sC5b-9 and C4d correlated significantly to ferritin (r = 0.64, P < 0.001; r = 0.69, P < 0.001). C4d, sC5b-9, and C5a correlated with antiviral antibodies, but not with viral load. Systemic complement activation is associated with respiratory failure in COVID-19 patients and provides a rationale for investigating complement inhibitors in future clinical trials.
Gut microbiota alterations have been reported in hospitalized COVID-19 patients, with reduced alpha diversity and altered microbiota composition related to respiratory failure. However, data ...regarding gut microbiota and mortality are scarce.
Rectal swabs for gut microbiota analyses were collected within 48 h after hospital admission (baseline; n = 123) and three-month post-admission (n = 50) in a subset of patients included in the Norwegian SARS-CoV2 cohort study. Samples were analysed by sequencing the 16S rRNA gene. Gut microbiota diversity and composition at baseline were assessed in relation to need for intensive care unit (ICU) admission during hospitalization. The primary objective was to investigate whether the ICU-related gut microbiota was associated with 60-day mortality.
Gut microbiota diversity (Shannon index) at baseline was lower in COVID-19 patients requiring ICU admission during hospitalization than in those managed in general wards. A dysbiosis index representing a balance of enriched and reduced taxa in ICU compared with ward patients, including decreased abundance of butyrate-producing microbes and enrichment of a partly oral bacterial flora, was associated with need of ICU admission independent of antibiotic use, dexamethasone use, chronic pulmonary disease, PO
/FiO
ratio, C-reactive protein, neutrophil counts or creatinine levels (adjusted p < 0.001). The ICU-related dysbiosis index at baseline correlated with systemic inflammation and was associated with 60-day mortality in univariate analyses (Hazard ratio 3.70 2.00-8.6, p < 0.001), as well as after separate adjustment for covariates. At the three-month follow-up, the dysbiosis index remained elevated in ICU patients compared with ward patients (adjusted p = 0.007).
Although our data should be regarded as exploratory due to low number of clinical end points, they suggest that gut microbiota alterations during hospitalization could be related to poor prognosis after severe COVID-19. Larger studies of gut involvement during COVID-19 in relation to long-term clinical outcome are warranted. Trial registration NCT04381819 . Retrospectively registered May 11, 2020.
Prediction models should be externally validated to assess their performance before implementation. Several prediction models for coronavirus disease-19 (COVID-19) have been published. This ...observational cohort study aimed to validate published models of severity for hospitalized patients with COVID-19 using clinical and laboratory predictors.
Prediction models fitting relevant inclusion criteria were chosen for validation. The outcome was either mortality or a composite outcome of mortality and ICU admission (severe disease). 1295 patients admitted with symptoms of COVID-19 at Kings Cross Hospital (KCH) in London, United Kingdom, and 307 patients at Oslo University Hospital (OUH) in Oslo, Norway were included. The performance of the models was assessed in terms of discrimination and calibration.
We identified two models for prediction of mortality (referred to as Xie and Zhang1) and two models for prediction of severe disease (Allenbach and Zhang2). The performance of the models was variable. For prediction of mortality Xie had good discrimination at OUH with an area under the receiver-operating characteristic (AUROC) 0.87 95% confidence interval (CI) 0.79-0.95 and acceptable discrimination at KCH, AUROC 0.79 0.76-0.82. In prediction of severe disease, Allenbach had acceptable discrimination (OUH AUROC 0.81 0.74-0.88 and KCH AUROC 0.72 0.68-0.75). The Zhang models had moderate to poor discrimination. Initial calibration was poor for all models but improved with recalibration.
The performance of the four prediction models was variable. The Xie model had the best discrimination for mortality, while the Allenbach model had acceptable results for prediction of severe disease.
The pathogenesis of coronavirus disease 2019 (COVID-19) is still incompletely understood, but it seems to involve immune activation and immune dysregulation.
We examined the parameters of activation ...of different leukocyte subsets in COVID-19–infected patients in relation to disease severity.
We analyzed plasma levels of myeloperoxidase (a marker of neutrophil activation), soluble (s) CD25 (sCD25) and soluble T-cell immunoglobulin mucin domain-3 (sTIM-3) (markers of T-cell activation and exhaustion), and sCD14 and sCD163 (markers of monocyte/macrophage activation) in 39 COVID-19–infected patients at hospital admission and 2 additional times during the first 10 days in relation to their need for intensive care unit (ICU) treatment.
Our major findings were as follows: (1) severe clinical outcome (ICU treatment) was associated with high plasma levels of sTIM-3 and myeloperoxidase, suggesting activated and potentially exhausted T cells and activated neutrophils, respectively; (2) in contrast, sCD14 and sCD163 showed no association with need for ICU treatment; and (3) levels of sCD25, sTIM-3, and myeloperoxidase were inversely correlated with degree of respiratory failure, as assessed by the ratio of Pao2 to fraction of inspired oxygen, and were positively correlated with the cardiac marker N-terminal pro-B–type natriuretic peptide.
Our findings suggest that neutrophil activation and, in particular, activated T cells may play an important role in the pathogenesis of COVID-19 infection, suggesting that T-cell–targeted treatment options and downregulation of neutrophil activation could be of importance in this disorder.
OBJECTIVES:
Increase of nucleated RBCs in peripheral blood has been shown to be predictive of mortality in ICU patients. The aim of this study was to explore the prognostic value of nucleated RBCs in ...the first blood sample taken at admission to the emergency department from patients with suspected sepsis.
DESIGN:
Single-center prospective cohort study.
SETTING:
Emergency department.
PATIENTS:
One-thousand two-hundred thirty-one consecutive adult patients with suspected sepsis were included in a prospective quality register-based cohort study. Inclusion criteria were as follows: patients received in rapid response team with blood cultures taken and immediate antibiotics given in the emergency department.
Intervention:
Not applicable.
MEASUREMENT AND MAIN RESULTS:
Nucleated RBCs, Sequential Organ Failure Assessment score, Quick Sequential Organ Failure Assessment, Charlson Comorbidity Index, and commonly used laboratory tests measured in the emergency department were compared with 30-day mortality. Nvaucleated RBC counts were divided into five groups, called “Nucleated RBC score,” according to nucleated RBC count levels and analyzed with logistic regression together with the Sequential Organ Failure Assessment score and Charlson Comorbidity Index. Of the 262 patients with nucleated RBCs equal to or higher than the detection limit (0.01 × 10
9
/L), 26% died within 30 days, compared with 12% of the 969 patients with nucleated RBCs below the detection limit (
p
< 0.0001). Mortality was significantly higher for each increase in Nucleated RBC score, except from score 2 to 3, and was 62% in the highest group. In multivariate logistic regression, odds ratios for 30-day mortality were as follows: Nucleated RBC score: 1.33 (95% CI, 1.13–1.56), Sequential Organ Failure Assessment score: 1.32 (1.29–1.56), and Charlson Comorbidity Index: 1.17 (1.09–1.25).
CONCLUSIONS:
Most patients with suspected sepsis in emergency department had undetectable nucleated RBCs at admission to the emergency department. However, increased nucleated RBCs significantly predicted 30-day mortality. Nucleated RBCs may provide additional prognostic information to Sequential Organ Failure Assessment score and other laboratory tests.
The Sequential Organ Failure Assessment (SOFA) was chosen in the definition of sepsis due to superior validity in predicting mortality. However, few studies have assessed the contributions of acute ...versus chronic organ failures to SOFA for mortality prediction.
The main objective in this study was to assess the relative importance of chronic and acute organ failures in mortality prediction in patients with suspected sepsis at hospital admission. We also evaluated how the presence of infection influenced the ability of SOFA to predict 30-day mortality.
Single-center prospective cohort study including 1,313 adult patients with suspected sepsis in rapid response teams in the emergency department.
The main outcome was 30-day mortality. We measured the maximum total SOFA score during admission (SOFATotal), whereas preexisting chronic organ failure SOFA (SOFAChronic) score was assessed by chart review, allowing calculation of the corresponding acute SOFA (SOFAAcute) score. Likelihood of infection was determined post hoc as "No infection" or "Infection."
SOFAAcute and SOFAChronic were both associated with 30-day mortality, adjusted for age and sex (adjusted odds ratios AORs, 1.3; 95% CI, 1.3-14 and 1.3; 1.2-1.7), respectively. Presence of infection was associated with lower 30-day mortality (AOR, 0.4; 95% CI, 0.2-0.6), even when corrected for SOFA. In "No infection" patients, SOFAAcute was not associated with mortality (AOR, 1.1; 95% CI, 1.0-1.2), and in this subgroup, neither SOFAAcute greater than or equal to 2 (relative risk RR, 1.1; 95% CI, 0.6-1.8) nor SOFATotal greater than or equal to 2 (RR, 3.6; 95% CI, 0.9-14.1) was associated with higher mortality.
Chronic and acute organ failures were equally associated with 30-day mortality in suspected sepsis. A substantial part of the total SOFA score was due to chronic organ failure, calling for caution when using total SOFA in defining sepsis and as an outcome in intervention studies. SOFA's mortality prediction ability was highly dependent on actual presence of infection.
Background
T‐cell activation is associated with an adverse outcome in COVID‐19, but whether T‐cell activation and exhaustion relate to persistent respiratory dysfunction and death is unknown.
...Objectives
To investigate whether T‐cell activation and exhaustion persist and are associated with prolonged respiratory dysfunction and death after hospitalization for COVID‐19.
Methods
Plasma and serum from two Norwegian cohorts of hospitalized patients with COVID‐19 (n = 414) were analyzed for soluble (s) markers of T‐cell activation (sCD25) and exhaustion (sTim‐3) during hospitalization and follow‐up.
Results
Both markers were strongly associated with acute respiratory failure, but only sTim‐3 was independently associated with 60‐day mortality. Levels of sTim‐3 remained elevated 3 and 12 months after hospitalization and were associated with pulmonary radiological pathology after 3 months.
Conclusion
Our findings suggest prolonged T‐cell exhaustion is an important immunological sequela, potentially related to long‐term outcomes after severe COVID‐19.
Several studies have examined parameters of increased thrombogenicity in COVID-19, but studies examining their association with long-term outcome and potential effects of antiviral agents in ...hospitalized patients with COVID-19 are scarce.
To evaluate plasma levels of hemostatic proteins during hospitalization in relation to disease severity, treatment modalities, and persistent pulmonary pathology after 3 months.
In 165 patients with COVID-19 recruited into the NOR-Solidarity trial (NCT04321616) and randomized to treatment with hydroxychloroquine, remdesivir, or standard of care, we analyzed plasma levels of hemostatic proteins during the first 10 days of hospitalization (n = 160) and at 3 months of follow-up (n = 100) by enzyme immunoassay.
Our main findings were as follows: (i) tissue plasminogen activator (tPA) and tissue factor pathway inhibitor (TFPI) were increased in patients with severe disease (ie, the combined endpoint of respiratory failure Po2-to-FiO2 ratio, <26.6 kPa or need for treatment at an intensive care unit) during hospitalization. Compared to patients without severe disease, tPA levels were a median of 42% (P < .001), 29% (P = .002), and 36% (P = .015) higher at baseline, 3 to 5 days, and 7 to 10 days, respectively. For TFPI, median levels were 37% (P = .003), 25% (P < .001), and 10% (P = .13) higher in patients with severe disease at these time points, respectively. No changes in thrombin-antithrombin complex; alpha 2-antiplasmin; a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13; or antithrombin were observed in relation to severe disease. (ii) Patients treated with remdesivir had lower levels of TFPI than those in patients treated with standard of care alone. (iii) TFPI levels during hospitalization, but not at 3 months of follow-up, were higher in those with persistent pathology on chest computed tomography imaging 3 months after hospital admission than in those without such pathology. No consistent changes in thrombin-antithrombin complex, alpha 2-antiplasmin, ADAMTS-13, tPA, or antithrombin were observed in relation to pulmonary pathology at 3 months of follow-up.
TFPI and tPA are associated with severe disease in hospitalized patients with COVID-19. For TFPI, high levels measured during the first 10 days of hospitalization were also associated with persistent pulmonary pathology even 3 months after hospital admittance.
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•Blood clotting laboratory tests were performed in hospital and 3 months later in severe COVID-19.•Tissue factor pathway inhibitor correlated with severity and 3-month lung pathology.•Tissue plasminogen activator correlated with disease severity.•Tissue factor pathway inhibitor and tissue plasminogen activator may be involved in the pathogenesis of severe COVID-19 disease.
Background
Prognostic markers for disease severity and identification of therapeutic targets in COVID‐19 are urgently needed. We have studied innate and adaptive immunity on protein and ...transcriptomic level in COVID‐19 patients with different disease severity at admission and longitudinally during hospitalization.
Methods
Peripheral blood mononuclear cells (PBMCs) were collected at three time points from 31 patients included in the Norwegian SARS‐CoV‐2 cohort study and analysed by flow cytometry and RNA sequencing. Patients were grouped as either mild/moderate (n = 14), severe (n = 11) or critical (n = 6) disease in accordance with WHO guidelines and compared with patients with SARS‐CoV‐2‐negative bacterial sepsis (n = 5) and healthy controls (n = 10).
Results
COVID‐19 severity was characterized by decreased interleukin 7 receptor alpha chain (CD127) expression in naïve CD4 and CD8 T cells. Activation (CD25 and HLA‐DR) and exhaustion (PD‐1) markers on T cells were increased compared with controls, but comparable between COVID‐19 severity groups. Non‐classical monocytes and monocytic HLA‐DR expression decreased whereas monocytic PD‐L1 and CD142 expression increased with COVID‐19 severity. RNA sequencing exhibited increased plasma B‐cell activity in critical COVID‐19 and yet predominantly reduced transcripts related to immune response pathways compared with milder disease.
Conclusion
Critical COVID‐19 seems to be characterized by an immune profile of activated and exhausted T cells and monocytes. This immune phenotype may influence the capacity to mount an efficient T‐cell immune response. Plasma B‐cell activity and calprotectin were higher in critical COVID‐19 while most transcripts related to immune functions were reduced, in particular affecting B cells. The potential of these cells as therapeutic targets in COVID‐19 should be further explored.
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