ABSTRACT
Background: Cumulative research show association of neutrophils and neutrophil extracellular traps (NETs) with poor outcomes in severe COVID-19. However, to date, there is no curative intent therapy able to block neutrophil/NETs-mediated progression of multi-organ dysfunction. Because of emerging neutrophil heterogeneity, the study of subsets of circulating NET-forming neutrophils [NET + Ns] as mediators of multi-organ failure progression among patients with COVID-19 is critical to identification of therapeutic targets. Methods: We conducted a prospective observational study of circulating levels of CD11b + [NET + N] immunotyped for dual endothelin-1/signal peptide receptor (DEspR ±) expression by quantitative immunofluorescence-cytology and causal mediation analysis. In 36 consented adults hospitalized with mod-severe COVID-19, May to September 2020, we measured acute multi-organ failure via SOFA-scores and respiratory failure via SaO2/FiO2 (SF)-ratio at time points t1 (average 5.5 days from ICU/hospital admission) and t2 (the day before ICU-discharge or death), and ICU-free days at day28 (ICUFD). Circulating absolute neutrophil counts (ANC) and [NET + N] subset-specific counts were measured at t1. Spearman correlation and causal mediation analyses were conducted. Results: Spearman correlation analyses showed correlations of t1-SOFA with t2-SOFA (rho r S = 0.80) and ICUFD (r S = -0.76); circulating DEspR + [NET + Ns] with t1-SOFA (r S = 0.71), t2-SOFA (r S = 0.62), and ICUFD (r S = -0.63), and ANC with t1-SOFA (r S = 0.71), and t2-SOFA (r S = 0.61).Causal mediation analysis identified DEspR + [NET + Ns] as mediator of 44.1% [95% CI:16.5,110.6] of the causal path between t1-SOFA (exposure) and t2-SOFA (outcome), with 46.9% [15.8,124.6] eliminated when DEspR + [NET + Ns] were theoretically reduced to zero. Concordantly, DEspR + [NET + Ns] mediated 47.1% [22.0,72.3%] of the t1-SOFA to ICUFD causal path, with 51.1% [22.8,80.4%] eliminated if DEspR + [NET + Ns] were reduced to zero. In patients with t1-SOFA > 1, the indirect effect of a hypothetical treatment eliminating DEspR + [NET + Ns] projected a reduction of t2-SOFA by 0.98 [0.29,2.06] points and ICUFD by 3.0 [0.85,7.09] days. In contrast, there was no significant mediation of SF-ratio through DEspR + [NET + Ns], and no significant mediation of SOFA-score through ANC. Conclusions: Despite equivalent correlations, DEspR + [NET + Ns], but not ANC, mediated progression of multi-organ failure in acute COVID-19, and its hypothetical reduction is projected to improve ICUFD. These translational findings warrant further studies of DEspR + [NET + Ns] as potential patient-stratifier and actionable therapeutic target for multi-organ failure in COVID-19. Supplementary Information: The online version contains supplementary material available at 10.1186/s41231-023-00143-x.
ABSTRACT
Background: Cumulative research show association of neutrophils and neutrophil extracellular traps (NETs) with poor outcomes in severe COVID-19. However, to date, no curative intent therapy has been identified to block neutrophil/NETs-mediated progression of multi-organ dysfunction. Because of emerging neutrophil heterogeneity, the study of subsets of circulating neutrophil-extracellular trap (NET)-forming neutrophils [NET+Ns] as mediators of multi-organ failure progression among patients with COVID-19 is critical to identification of therapeutic targets. Methods: We conducted a prospective observational study of circulating levels of CD11b+[NET+N] immunotyped for dual endothelin-1/signal peptide receptor, (DEspR±) expression by quantitative immunofluorescence-cytology and causal mediation analysis. In 36 consented adults hospitalized with mod-severe COVID-19, May to September 2020, we measured acute multi-organ failure via SOFA-scores and respiratory failure via SaO2/FiO2 (SF)ratio at time points t1 (average 5.5 days from ICU/hospital admission) and t2 (the day before ICU-discharge or death), and ICU-free days at day28 (ICUFD). Circulating absolute neutrophil counts (ANC) and [NET+N] subset-specific counts were measured at t1. Spearman correlation and causal mediation analyses were conducted. Results: Spearman correlation analyses showed correlations of t1-SOFA with t2-SOFA (rho rS=0.80) and ICUFD (rS=-0.76); circulating DEspR+[NET+Ns] with t1-SOFA (rS= 0.71), t2-SOFA (rS =0.62), and ICUFD (rS =-0.63), and ANC with t1-SOFA (rS=0.71), and t2-SOFA (rS=0.61). Causal mediation analysis identified DEspR+[NET+Ns] as mediator of 44.1% [95% CI:16.5,110.6] of the causal path between t1-SOFA (exposure) and t2-SOFA (outcome), with 46.9% [15.8,124.6] eliminated when DEspR+[NET+Ns] were theoretically reduced to zero. Concordantly, DEspR+[NET+Ns] mediated 47.1% [22.0,72.3%] of the t1-SOFA to ICUFD causal path, with 51.1% [22.8,80.4%] eliminated if DEspR+[NET+Ns] were reduced to zero. In patients with t1-SOFA >1, the indirect effect of a hypothetical treatment eliminating DEspR+[NET+Ns] projected a reduction of t2-SOFA by 0.98 [0.29,2.06] points and ICUFD by 3.0 [0.85,7.09] days. In contrast, there was no significant mediation of SF-ratio through DEspR+[NET+Ns], and no significant mediation of SOFA-score through ANC. Conclusions: Despite equivalent correlations, DEspR+[NET+Ns], but not ANC, mediated progression of multi-organ failure in acute COVID-19, and its hypothetical reduction is projected to improve ICUFD. These translational findings warrant further studies of DEspR+[NET+Ns] as potential patient-stratifier and actionable therapeutic target for multi-organ failure in COVID-19.
Subject(s)
Multiple Organ Failure , COVID-19 , Respiratory InsufficiencyABSTRACT
A million Canadian workers suddenly became temporarily laid off (TLO) early into the pandemic. How did this affect mental health? Guided by the Stress Process Model (SPM), we would expect that this job disruption should increase psychological distress. However, given the unique context surrounding the early period of the pandemic, we advance the forced vacation hypothesis, which argues that those who became TLO would—at least initially—report lower levels of distress. To address this puzzle, we use a mixed-methods approach combining a national longitudinal survey dataset and in-depth interviews. Our quantitative analyses reveal that individuals who were TLO had lower distress in April 2020 compared with their peers who continued working. Our interviews uncover several potential explanations for these patterns. The findings provide an elaboration to the SPM as the pandemic context altered the meaning of being TLO, making it feel like a "forced vacation”—at least initially. © The Author(s) 2022.
ABSTRACT
Neutrophil-mediated secondary tissue injury underlies acute respiratory distress syndrome (ARDS) and progression to multi-organ-failure (MOF) and death, processes linked to COVID-19-ARDS. This secondary tissue injury arises from dysregulated neutrophils and neutrophil extracellular traps (NETs) intended to kill pathogens, but instead cause cell-injury. Insufficiency of pleiotropic therapeutic approaches delineate the need for inhibitors of dysregulated neutrophil-subset(s) that induce subset-specific apoptosis critical for neutrophil function-shutdown. We hypothesized that neutrophils expressing the pro-survival dual endothelin-1/VEGF-signal peptide receptor, DEspR, are apoptosis-resistant like DEspR+ cancer-cells, hence comprise a consequential pathogenic neutrophil-subset in ARDS and COVID-19-ARDS. Here, we report the significant association of increased peripheral DEspR+CD11b+ neutrophil-counts with severity and mortality in ARDS and COVID-19-ARDS, and intravascular NET-formation, in contrast to DEspR[-] neutrophils. We detect DEspR+ neutrophils and monocytes in lung tissue patients in ARDS and COVID-19-ARDS, and increased neutrophil RNA-levels of DEspR ligands and modulators in COVID-19-ARDS scRNA-seq data-files. Unlike DEspR[-] neutrophils, DEspR+CD11b+ neutrophils exhibit delayed apoptosis, which is blocked by humanized anti-DEspR-IgG4S228P antibody, hu6g8, in ex vivo assays. Ex vivo live-cell imaging of Rhesus-derived DEspR+CD11b+ neutrophils showed hu6g8 target-engagement, internalization, and induction of apoptosis. Altogether, data identify DEspR+CD11b+ neutrophils as a targetable 'rogue' neutrophil-subset associated with severity and mortality in ARDS and COVID-19-ARDS.
Subject(s)
COVID-19 , Extracellular Traps , Respiratory Distress Syndrome , Humans , Immunophenotyping , NeutrophilsABSTRACT
Rationale: D-dimer is primarily used in the diagnosis of venous thromboembolic (VTE) disease. Recently the Ddimer test has been used as a marker of inflammation in COVID-19 pneumonia and has been shown to correlate with worse outcomes. An understanding of trajectories and relation to clot burden and outcomes of this novel use of serial measurements of D-dimer in COVID-19 ICU patients remains to be explored. Methods: We reviewed patients who were admitted to the Northwestern Hospital COVID ICUs from 3/1/20 to 7/31/20. We obtained demographics, d-dimer lab values, venous duplex studies from upper and lower extremities (UE/LE dopplers), CT-angiogram (CTA) reports, and mortality outcomes from our electronic medical record database. Reports were processed using string analysis with manual physician validation. Analysis was done in R with nonparametric numeric variables being compared by two-tailed Mann Whitney tests. Results: We had 370 patients in our cohort, with median (interquartile range (IQR)) age being 60 (49-69), 229/370 (62%) male, 128 (35%) of Hispanic ethnicity, 117 (32%) of African-American ethnicity, and 135 (36%) of Caucasian descent. 70 patients died (19%). The total number of VTE imaging tests included: 87 CTAs, 102 UE dopplers, and 232 LE dopplers. Clot was discovered in 43/102 (42%) UE dopplers, 62/232 (27%) of LE dopplers, and 25/87 (29%) of CTAs. Patients underwent a median of 2 (1-3) imaging studies, and 10 (4-20) d-dimer measurements. 79 unique patients (21%) had VTE detected. There was no statistically significant difference in age between the clot vs noclot groups: 57(45-68) vs 61(49-59) years, p=0.34, or BMI: 30.5(25.6-34.8) in clot vs 29(25.4-34.5) kg/m2 in no-clot group (p=0.55). Mortality was significantly higher at 36% in the clot group vs 15% in the group without clot (p<0.005). Hospital length of stay in the group with clot was significantly longer at 30.5(20.3-43.5) days vs no-clot 14(7.9-18.5) days (p<0.0001). The clot group had higher initial d-dimer values 2,236(752-3,654) ng/ml than the no-clot group 757(395-1,940) (p<0.0001), and also higher peak d-dimer values 9,476(3,353-16,595) vs 2,113(686-3,689) ng/ml (p<0.0001). Conclusion: Critically ill COVID-19 patients exhibit a high rate of clot formation. Here we describe a cohort of ICU patients with COVID-19 and their demographics, d-dimer trends, clot burden, and outcomes. Future studies will focus on predictors of clot presence and outcomes based on ddimer trends.