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BackgroundEffective regulation of complement activation may be crucial to preserving complement function during ARDS. Factor H (FH) is the primary negative regulator of the alternative pathway (AP) of complement. We hypothesized that preserved FH levels are associated with decreased complement activation and reduced mortality during ARDS.MethodsTotal AP function was measured by serum hemolytic assay (AH50) using available samples from the ARDSnet LARMA trial (N=218). Factor B (FB) and FH levels were quantified by ELISA using samples from the ARDSnet LARMA and SAILS (N=224) trials. Meta-analyses included previously quantified AH50, FB, and FH values from an observational registry (ALIR). Complement C3, and complement activation products C3a and Ba plasma levels were measured in SAILS.ResultsAH50>median was associated with reduced mortality in meta-analysis of LARMA and ALIR [hazard ratio (HR)=0.66, 95% confidence interval (CI) 0.45–0.96]. In contrast, patients in the lowest AH50 quartile demonstrated relative deficiency of both FB and FH. Relative deficiency of FB [HR 1.99, CI 1.44–2.75], or FH [HR 1.52, CI 1.09–2.11], were associated with increased mortality in meta-analysis of LARMA, SAILS, and ALIR. Relative FH deficiency was associated with increased factor consumption as evidenced by lower FB and C3 levels and higher Ba:FB and C3a:C3 ratios. Higher FH levels associated with lower inflammatory markers.ConclusionsRelative FH deficiency, higher Ba:FB and C3a:C3 ratios, and lower FB and C3 levels suggest a subset of ARDS with complement factor exhaustion, impaired AP function, and increased mortality that may be amenable to therapeutic targeting.

Background The advent of culture-independent, next-generation DNA sequencing has led to the discovery of distinct lung bacterial communities. Studies of lung microbiome taxonomy often reveal only subtle differences between health and disease, but host recognition and response may distinguish the members of similar bacterial communities in different populations. Magnetic-activated cell sorting has been applied to the gut microbiome to identify the numbers and types of bacteria eliciting a humoral response. We adapted this technique to examine the populations of immunoglobulin-bound bacteria in the lung. Methods Sixty-four individuals underwent bronchoalveolar lavage (BAL). We separated immunoglobulin G-bound bacteria using magnetic-activated cell sorting and sequenced the 16S rRNA gene on the Illumina MiSeq platform. We compared microbial sequencing data in IgG-bound bacterial communities compared to raw BAL then examined the differences in individuals with and without HIV as a representative disease state. Results Immunoglobulin G-bound bacteria were identified in all individuals. The community structure differed when compared to raw BAL, and there was a greater abundance of Pseudomonas and fewer oral bacteria in IgG-bound BAL. Examination of IgG-bound communities in individuals with HIV demonstrated the differences in Ig-bound bacteria by HIV status that were not seen in a comparison of raw BAL, and greater numbers of immunoglobulin-bound bacteria were associated with higher pulmonary cytokine levels. Conclusions We report a novel application of magnetic-activated cell sorting to identify immunoglobulin G-bound bacteria in the lung. This technique identified distinct bacterial communities which differed in composition from raw bronchoalveolar lavage, revealing the differences not detected by traditional analyses. Cytokine response was also associated with differential immunoglobulin binding of lung bacteria, suggesting the functional importance of these communities.

Background Fatty acid oxidation (FAO) defects have been implicated in experimental models of acute lung injury and associated with poor outcomes in critical illness. In this study, we examined acylcarnitine profiles and 3-methylhistidine as markers of FAO defects and skeletal muscle catabolism, respectively, in patients with acute respiratory failure. We determined whether these metabolites were associated with host-response ARDS subphenotypes, inflammatory biomarkers, and clinical outcomes in acute respiratory failure. Methods In a nested case–control cohort study, we performed targeted analysis of serum metabolites of patients intubated for airway protection (airway controls), Class 1 (hypoinflammatory), and Class 2 (hyperinflammatory) ARDS patients (N = 50 per group) during early initiation of mechanical ventilation. Relative amounts were quantified by liquid chromatography high resolution mass spectrometry using isotope-labeled standards and analyzed with plasma biomarkers and clinical data. Results Of the acylcarnitines analyzed, octanoylcarnitine levels were twofold increased in Class 2 ARDS relative to Class 1 ARDS or airway controls (P = 0.0004 and P = 0.004). In addition, acetylcarnitine and 3-methylhistidine were increased in Class 2 relative to Class 1 and positively correlated with inflammatory biomarkers. In all patients within the study with acute respiratory failure, increased 3-methylhistidine was observed in non-survivors at 30 days (P = 0.0018), while octanoylcarnitine was increased in patients requiring vasopressor support but not in non-survivors (P = 0.0001 and P = 0.28, respectively). Conclusions This study demonstrates that increased levels of acetylcarnitine, octanoylcarnitine, and 3-methylhistidine distinguish Class 2 from Class 1 ARDS patients and airway controls. Octanoylcarnitine and 3-methylhistidine were associated with poor outcomes in patients with acute respiratory failure across the cohort independent of etiology or host-response subphenotype. These findings suggest a role for serum metabolites as biomarkers in ARDS and poor outcomes in critically ill patients early in the clinical course.

Critical illness myopathy (CIM) and critical illness polyneuropathy (CIP) are common disorders associated with substantial morbidity. Electrodiagnostic studies (EDx) are effective in diagnosing CIM/CIP and identifying mimicking conditions. We surveyed intensive care unit (ICU) providers to better understand their approach to ICU-acquired weakness (ICU-AW) and the perceived utility of EDx.This was a single health system, Web-based survey of ICU providers.Survey responses were received from 52 providers with a response rate of 22.1%. Most providers were somewhat familiar with CIM/CIP and median perceived prevalence was 30-49%. The majority (92.3%) of providers had no standard evaluation approach for ICU-AW. Electrodiagnostic testing was commonly considered, but many providers obtained it infrequently in presumed CIM/CIP cases. Electrodiagnostic studies were used to rule out other causes of weakness or to confirm the diagnosis of CIM/CIP. Many providers ordered EDx within 1 wk of identifying weakness. Finally, EDx were overshadowed by personal experience as the most helpful management tool for ICU-AW.Overall, ICU providers perceive that CIM/CIP are commonly encountered, but they may not have a standard approach to evaluation. Clinical experience increased familiarity of ICU-AW and is central to management. EDx results are usually thought to be helpful, albeit not often ordered, and more study is needed to determine when implementation is of most assistance. Increasing education and developing institutional standards may lead to increased awareness and improved evaluation of CIM/CIP, but more study is needed to determine if algorithmic approaches would change patient outcomes.

Background Excessive complement activation has been implicated in the pathogenesis of coronavirus disease 2019 (COVID-19), but the mechanisms leading to this response remain unclear. Methods We measured plasma levels of key complement markers, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA and antibodies against SARS-CoV-2 and seasonal human common cold coronaviruses (CCCs) in hospitalized patients with COVID-19 of moderate (n = 18) and critical severity (n = 37) and in healthy controls (n = 10). Results We confirmed that complement activation is systemically increased in patients with COVID-19 and is associated with a worse disease outcome. We showed that plasma levels of C1q and circulating immune complexes were markedly increased in patients with severe COVID-19 and correlated with higher immunoglobulin (Ig) G titers, greater complement activation, and higher disease severity score. Additional analyses showed that the classical pathway was the main arm responsible for augmented complement activation in severe patients. In addition, we demonstrated that a rapid IgG response to SARS-CoV-2 and an anamnestic IgG response to the nucleoprotein of the CCCs were strongly correlated with circulating immune complex levels, complement activation, and disease severity. Conclusions These findings indicate that early, nonneutralizing IgG responses may play a key role in complement overactivation in severe COVID-19. Our work underscores the urgent need to develop therapeutic strategies to modify complement overactivation in patients with COVID-19.

Purpose Three continuous dosing strategies of cisatracurium (CIS) for acute respiratory distress syndrome (ARDS) have been described in the literature. After implementation of a ventilator synchrony protocol (VSP), we sought to determine which continuous CIS dosing strategy utilized the least amount of drug without compromising efficacy. Methods We retrospectively reviewed patients with ARDS receiving continuous CIS from January 1, 2013 to December 31, 2018. We categorized patients into one of three dosing strategies: fixed dose (FD), titration based solely on train-of-four (TOF), or the VSP. We documented drug consumption and determined efficacy by comparing the change in PaO2/FiO2 ratio (P/F) and oxygenation index (OI) from baseline up to 48 h. Results A total of 1047 patients were screened, and 189 met inclusion criteria (VSP = 69, TOF = 99, FD = 21). Drug consumption (mg) was significantly lower in the VSP arm: 415 [IQR 318–528] compared to both the TOF: 665 [IQR 472–927] and the FD arms: 1730 [IQR 1695–1800], p < 0.001 for each. The change in P/F and OI from baseline were statistically equivalent at all time points. Conclusion Without impacting efficacy of gas exchange, a protocol using ventilator synchrony for CIS titration required significantly less drug compared to TOF-based titration and a fixed dosing regimen.

PurposeEnhanced understanding of the dynamic changes in the dysregulated inflammatory response in COVID-19 may help improve patient selection and timing for immunomodulatory therapies.MethodsWe enrolled 323 COVID-19 inpatients on different levels of baseline respiratory support: i) Low Flow Oxygen (37%), ii) Non-Invasive Ventilation or High Flow Oxygen (NIV_HFO, 29%), iii) Invasive Mechanical Ventilation (IMV, 27%), and iv) Extracorporeal Membrane Oxygenation (ECMO, 7%). We collected plasma samples upon enrollment and days 5 and 10 to measure host-response biomarkers. We classified subjects into inflammatory subphenotypes using two validated predictive models. We examined clinical, biomarker and subphenotype trajectories and outcomes during hospitalization.ResultsIL-6, procalcitonin, and Angiopoietin-2 were persistently elevated in patients at higher levels of respiratory support, whereas sRAGE displayed the inverse pattern. Patients on NIV_HFO at baseline had the most dynamic clinical trajectory, with 26% eventually requiring intubation and exhibiting worse 60-day mortality than IMV patients at baseline (67% vs. 35%, pConclusionsLongitudinal study of systemic host responses in COVID-19 revealed substantial and predictive inter-individual variability, influenced by baseline levels of respiratory support and concurrent immunomodulatory therapies.

Lung epithelial cell death is a prominent feature of acute lung injury and acute respiratory distress syndrome (ALI/ARDS), which results from severe pulmonary infection leading to respiratory failure. Multiple mechanisms are believed to contribute to the death of epithelia; however, limited data propose a role for epigenetic modifiers. In this study, we report that a chromatin modulator protein arginine N-methyltransferase 4/coactivator-associated arginine methyltransferase 1 (PRMT4/CARM1) is elevated in human lung tissues with pneumonia and in experimental lung injury models. Here PRMT4 is normally targeted for its degradation by an E3 ubiquitin ligase, SCFFBXO9, that interacts with PRMT4 via a phosphodegron to ubiquitinate the chromatin modulator at K228 leading to its proteasomal degradation. Bacterial-derived endotoxin reduced levels of SCFFBXO9 thus increasing PRMT4 cellular concentrations linked to epithelial cell death. Elevated PRMT4 protein caused substantial epithelial cell death via caspase 3-mediated cell death signaling, and depletion of PRMT4 abolished LPS-mediated epithelial cell death both in cellular and murine injury models. These findings implicate a unique molecular interaction between SCFFBXO9 and PRMT4 and its regulation by endotoxin that impacts the life span of lung epithelia, which may play a key role in the pathobiology of tissue injury observed during critical respiratory illness.

Acute kidney injury (AKI) is common in patients hospitalized for COVID-19, complicating their clinical course and contributing to worse outcomes. Animal studies show that adenosine, inosine and guanosine protect the kidney against some types of AKI. However, until now there was no evidence in patients supporting the possibility that abnormally low kidney levels of adenosine, inosine and guanosine contribute to AKI. Here, we addressed the question as to whether these renoprotective purines are altered in the urine of COVID-19 patients with AKI. Purines were measured by employing ultra-high-performance liquid chromatography-tandem mass spectrometry with stable-isotope-labeled internal standards for each purine of interest. Compared with COVID-19 patients without AKI (n = 23), COVID-19 patients with AKI (n = 20) had significantly lower urine levels of adenosine (P P = 0.0008), and guanosine (P = 0.0008) (medians reduced by 85%, 48% and 61%, respectively) and lower levels (P = 0.0003; median reduced by 67%) of the 2nd messenger for A2A and A2B adenosine receptors, i.e., 3’,5’-cAMP. Moreover, in COVID-19 patients with AKI, urine levels of 8-aminoguanine (endogenous inhibitor of inosine and guanosine metabolism) were nearly abolished (P

BackgroundSecondary infection (SI) diagnosis in COVID-19 is challenging, due to overlapping clinical presentations, practical limitations in obtaining samples from the lower respiratory tract (LRT), and low sensitivity of microbiologic cultures.Research QuestionCan metagenomic sequencing of plasma microbial cell-free DNA (mcfDNA-Seq) help diagnose SIs complicating COVID-19?Study Design and MethodsWe enrolled 42 inpatients with COVID-19 classified as microbiologically-confirmed SI (Micro-SI, n=8), clinically-diagnosed SI (Clinical-SI, n=13, i.e. empiric antimicrobials), or no clinical suspicion for SI (No-Suspected-SI, n=21) at time of enrollment. From baseline and follow-up plasma samples (days 5 and 10 post-enrollment), we quantified mcfDNA for all detected microbes by mcfDNA sequencing and measured nine host-response biomarkers. From LRT samples among intubated subjects, we quantified bacterial burden with 16S rRNA gene quantitative PCR.ResultsWe performed mcfDNA-Seq in 82 plasma samples. Sequencing was successful in 60/82 (73.2%) samples, which had significantly lower levels of human cfDNA than failed samples (p10 mcfDNA, p=0.03).InterpretationHigh circulating levels of mcfDNA in a substantial proportion of patients with COVID-19 without clinical suspicion for SI suggest that SIs may often remain undiagnosed. McfDNA-Seq, when clinically available, can offer a non-invasive diagnostic tool for pathogen identification, with prognostic value on host inflammatory response and clinical outcomes.

Intensive care unit (ICU) delirium is associated with a proinflammatory state and poor outcomes. An epigenetic mechanism may modify inflammation.To identify inflammatory gene methylation trajectory groups and explore their clinical and demographic variability.Patients were at least 18 years old; received mechanical ventilation for at least 24 hours; had no brain disorder/injury, preexisting dementia, or positive toxicology screen; and were admitted to a medical or surgical/trauma ICU. Delirium was assessed (Confusion Assessment Method for the ICU) and blood samples were collected daily for up to 10 days. Methylation of 3 genes in the inflammatory pathway was quantified. Latent class analysis identified gene methylation trajectories, and variables (including delirium) were compared between trajectory groups.Of 68 patients (53% female, 88% White), 65% developed delirium. Of 3 methylation trajectories for IL6ST, the group with low initial methylation increasing over time included younger male patients who were less likely to have delirium, and the group with high initial methylation decreasing over time included older (P = .01) female (P = .05) patients who more often had delirium (P = .05). IL17C had 2 methylation trajectories without significant differences in delirium, age, or sex. IL13RA1 had 2 methylation trajectories without differences in delirium or age; the group with sustained high methylation had more female patients (P = .003).Temporal variability in inflammatory gene methylation occurs after ICU admission. Delirium, female sex, and older age were more common with higher IL6ST methylation that decreased over time. Larger studies are needed to further elucidate these relationships.

Rationale: There is an urgent need for improved understanding of the mechanisms and clinical characteristics of acute respiratory distress syndrome (ARDS) due to coronavirus disease (COVID-19). Objectives: To compare key demographic and physiologic parameters, biomarkers, and clinical outcomes of COVID-19 ARDS and ARDS secondary to direct lung injury from other etiologies of pneumonia. Methods: We enrolled 27 patients with COVID-19 ARDS in a prospective, observational cohort study and compared them with a historical, pre–COVID-19 cohort of patients with viral ARDS (n = 14), bacterial ARDS (n = 21), and ARDS due to culture-negative pneumonia (n = 30). We recorded clinical demographics; measured respiratory mechanical parameters; collected serial peripheral blood specimens for measurement of plasma interleukin (IL)-6, IL-8, and IL-10; and followed patients prospectively for patient-centered outcomes. We conducted between-group comparisons with nonparametric tests and analyzed time-to-event outcomes with Kaplan-Meier and Cox proportional hazards models. Results: Patients with COVID-19 ARDS had higher body mass index and were more likely to be Black, or residents of skilled nursing facilities, compared with those with non–COVID-19 ARDS (P < 0.05). Patients with COVID-19 had lower delivered minute ventilation compared with bacterial and culture-negative ARDS (post hoc P < 0.01) but not compared with viral ARDS. We found no differences in static compliance, hypoxemic indices, or carbon dioxide clearance between groups. Patients with COVID-19 had lower IL-6 levels compared with bacterial and culture-negative ARDS at early time points after intubation but no differences in IL-6 levels compared with viral ARDS. Patients with COVID-19 had longer duration of mechanical ventilation but similar 60-day mortality in both unadjusted and adjusted analyses. Conclusions: COVID-19 ARDS bears several similarities to viral ARDS but demonstrates lower minute ventilation and lower systemic levels of IL-6 compared with bacterial and culture-negative ARDS. COVID-19 ARDS was associated with longer dependence on mechanical ventilation compared with non–COVID-19 ARDS. Such detectable differences of COVID-19 do not merit deviation from evidence-based management of ARDS but suggest priorities for clinical research to better characterize and treat this new clinical entity.

INTRODUCTIONChest imaging is necessary for diagnosis of COVID-19 pneumonia, but current risk stratification tools do not consider radiographic severity. We quantified radiographic heterogeneity among inpatients with COVID-19 with the Radiographic Assessment of Lung Edema (RALE) score on Chest X-rays (CXRs).METHODSWe performed independent RALE scoring by ≥2 reviewers on baseline CXRs from 425 inpatients with COVID-19 (discovery dataset), we recorded clinical variables and outcomes, and measured plasma host-response biomarkers and SARS-CoV-2 RNA load from subjects with available biospecimens.RESULTSWe found excellent inter-rater agreement for RALE scores (intraclass correlation co-efficient=0.93). The required level of respiratory support at the time of baseline CXRs (supplemental oxygen or non-invasive ventilation [n=178]; invasive-mechanical ventilation [n=234], extracorporeal membrane oxygenation [n=13]) was significantly associated with RALE scores (median [interquartile range]: 20.0[14.1-26.7], 26.0[20.5-34.0] and 44.5[34.5-48.0], respectively, pCONCLUSIONReproducible assessment of radiographic severity revealed significant associations with clinical and physiologic severity, host-response biomarkers and clinical outcome in COVID-19 pneumonia. Incorporation of radiographic severity assessments may provide prognostic and treatment allocation guidance in patients hospitalized with COVID-19.

Determine the role of surfactant protein D (SPD) in sepsis.Murine in vivo study.Research laboratory at an academic medical center.SPD knockout (SPDSPDSPDEnteral SPD exacerbates mortality after CLP by facilitating colonization of the mouse gut with

Purpose To study the efficacy of lopinavir-ritonavir and hydroxychloroquine in critically ill patients with coronavirus disease 2019 (COVID-19). Methods Critically ill adults with COVID-19 were randomized to receive lopinavir-ritonavir, hydroxychloroquine, combination therapy of lopinavir-ritonavir and hydroxychloroquine or no antiviral therapy (control). The primary endpoint was an ordinal scale of organ support-free days. Analyses used a Bayesian cumulative logistic model and expressed treatment effects as an adjusted odds ratio (OR) where an OR > 1 is favorable. Results We randomized 694 patients to receive lopinavir-ritonavir (n = 255), hydroxychloroquine (n = 50), combination therapy (n = 27) or control (n = 362). The median organ support-free days among patients in lopinavir-ritonavir, hydroxychloroquine, and combination therapy groups was 4 (– 1 to 15), 0 (– 1 to 9) and—1 (– 1 to 7), respectively, compared to 6 (– 1 to 16) in the control group with in-hospital mortality of 88/249 (35%), 17/49 (35%), 13/26 (50%), respectively, compared to 106/353 (30%) in the control group. The three interventions decreased organ support-free days compared to control (OR [95% credible interval]: 0.73 [0.55, 0.99], 0.57 [0.35, 0.83] 0.41 [0.24, 0.72]), yielding posterior probabilities that reached the threshold futility (≥ 99.0%), and high probabilities of harm (98.0%, 99.9% and > 99.9%, respectively). The three interventions reduced hospital survival compared with control (OR [95% CrI]: 0.65 [0.45, 0.95], 0.56 [0.30, 0.89], and 0.36 [0.17, 0.73]), yielding high probabilities of harm (98.5% and 99.4% and 99.8%, respectively). Conclusion Among critically ill patients with COVID-19, lopinavir-ritonavir, hydroxychloroquine, or combination therapy worsened outcomes compared to no antiviral therapy. Supplementary Information The online version contains supplementary material available at 10.1007/s00134-021-06448-5.

Rationale: Host inflammatory responses have been strongly associated with adverse outcomes in critically ill patients, but the biologic underpinnings of such heterogeneous responses have not been d...

Utilizing publicly available ribonucleic acid sequencing data, we identified SCUBE1 as a BMPR2-related gene differentially expressed between induced pluripotent stem cell-endothelial cells derived from pulmonary arterial hypertension (PAH) patients carrying pathogenic BMPR2 mutations and control patients without mutations. Endothelial SCUBE1 expression was decreased by known triggers of PAH, and its down-regulation recapitulated known BMPR2-associated endothelial pathophenotypes in vitro. Meanwhile, SCUBE1 concentrations were reduced in plasma obtained from PAH rodent models and patients with PAH, whereas plasma concentrations were tightly correlated with hemodynamic markers of disease severity. Taken together, these data implicate SCUBE1 as a novel contributor to PAH pathogenesis with potential therapeutic, diagnostic, and prognostic applications.

Rationale: Complement is crucial for host defense but may also drive dysregulated inflammation. There is limited understanding of alternative complement function, which can amplify all complement a...

TLR8 (Toll-like receptor 8) is an intracellular pattern recognition receptor that senses RNA in endosomes to initiate innate immune signaling through NF-κB, and mechanisms regulating TLR8 protein abundance are not completely understood. Protein degradation is a cellular process controlling protein concentrations, accomplished largely through ubiquitin transfer directed by E3 ligase proteins to substrates. In the present study, we show that TLR8 has a short half-life in THP-1 monocytes (∼1 h) and that TLR8 is ubiquitinated and degraded in the proteasome. Treatment with the TLR8 agonist R848 causes rapid depletion of TLR8 concentrations at early time points, an effect blocked by proteasomal inhibition. We show a novel role for RNF216 (ring finger protein 216), an E3 ligase that targets TLR8 for ubiquitination and degradation. RNF216 overexpression reduces TLR8 concentrations, whereas RNF216 knockdown stabilizes TLR8. We describe a potential role for TLR8 activation by circulating RNA ligands in humans with acute respiratory distress syndrome (ARDS): Plasma and extracted RNA fractions from subjects with ARDS activated TLR8 in vitro. MicroRNA (miRNA) expression profiling revealed several circulating miRNAs from subjects with ARDS. miRNA mimics promoted TLR8 proteasomal degradation in THP-1 cells. These data show that TLR8 proteasomal disposal through RNF216 in response to RNA ligands regulates TLR8 cellular concentrations and may have implications for innate immune signaling. In addition, TLR8 activation by circulating RNA ligands may be a previously underrecognized stimulus contributing to excessive innate immune signaling characteristic of ARDS.

Monoclonal antibodies (mAb) that neutralize SARS-CoV-2 decrease hospitalization and death compared to placebo in patients with mild to moderate COVID-19; however, comparative effectiveness is unknown. We report the comparative effectiveness of bamlanivimab, bamlanivimab-etesevimab, and casirivimab-imdevimab.A learning health system platform trial in a U.S. health system enrolled patients meeting mAb Emergency Use Authorization criteria. An electronic health record-embedded application linked local mAb inventory to patient encounters and provided random mAb allocation. Primary outcome was hospital-free days to day 28. Primary analysis was a Bayesian model adjusting for treatment location, age, sex, and time. Inferiority was defined as 99% posterior probability of an odds ratio 1. Equivalence was defined as 95% posterior probability the odds ratio is within a given bound.Between March 10 and June 25, 2021, 1935 patients received treatment. Median hospital-free days were 28 (IQR 28, 28) for each mAb. Mortality was 0.8% (1/128), 0.8% (7/885), and 0.7% (6/922) for bamlanivimab, bamlanivimab-etesevimab, and casirivimab-imdevimab, respectively. Relative to casirivimab-imdevimab (n = 922), median adjusted odds ratios were 0.58 (95% credible interval [CI] 0.30-1.16) and 0.94 (95% CI 0.72-1.24) for bamlanivimab (n = 128) and bamlanivimab-etesevimab (n = 885), respectively. These odds ratios yielded 91% and 94% probabilities of inferiority of bamlanivimab versus bamlanivimab-etesevimab and casirivimab-imdevimab, and an 86% probability of equivalence between bamlanivimab-etesevimab and casirivimab-imdevimab.Among patients with mild to moderate COVID-19, bamlanivimab-etesevimab or casirivimab-imdevimab treatment resulted in 86% probability of equivalence. No treatment met prespecified criteria for statistical equivalence. Median hospital-free days to day 28 were 28 (IQR 28, 28) for each mAb.This work received no external funding. The U.S. government provided the reported mAb. This trial is registered at ClinicalTrials.gov, NCT04790786.

Rapid, continuous implementation of credible scientific findings and regulatory approvals is often slow in large, diverse health systems. The coronavirus disease 2019 (COVID-19) pandemic created a new threat to this common "slow to learn and adapt" model in healthcare. We describe how the University of Pittsburgh Medical Center (UPMC) committed to a rapid learning health system (LHS) model to respond to the COVID-19 pandemic.A treatment cohort study was conducted among 11 429 hospitalized patients (pediatric/adult) from 22 hospitals (PA, NY) with a primary diagnosis of COVID-19 infection (March 19, 2020 - June 6, 2021). Sociodemographic and clinical data were captured from UPMC electronic medical record (EMR) systems. Patients were grouped into four time-defined patient "waves" based on nadir of daily hospital admissions, with wave 3 (September 20, 2020 - March 10, 2021) split at its zenith due to high volume with steep acceleration and deceleration. Outcomes included changes in clinical practice (eg, use of corticosteroids, antivirals, and other therapies) in relation to timing of internal system analyses, scientific publications, and regulatory approvals, along with 30-day rate of mortality over time.The mean (SD) daily number of admissions across hospitals was 26 (29) with a maximum 7-day moving average of 107 patients. System-wide implementation of the use of dexamethasone, remdesivir, and tocilizumab occurred within days of release of corresponding seminal publications and regulatory actions. After adjustment for differences in patient clinical profiles over time, each month of hospital admission was associated with an estimated 5% lower odds of 30-day mortality (adjusted odds ratio [OR] = 0.95, 95% confidence interval: 0.93-0.97,In our large LHS, near real-time changes in clinical management of COVID-19 patients happened promptly as scientific publications and regulatory approvals occurred throughout the pandemic. Alongside these changes, patients with COVID-19 experienced lower adjusted 30-day mortality following hospital admission over time.

Plasma SARS-CoV-2 viral RNA (vRNA) levels are predictive of COVID-19 outcomes in hospitalized patients, but whether plasma vRNA reflects lower respiratory tract (LRT) vRNA levels is unclear. We compared plasma and LRT vRNA levels in serially collected samples from mechanically ventilated patients with COVID-19. LRT and plasma vRNA levels were strongly correlated at first sampling (n = 33, r = 0.83, P < 10−9) and then declined in parallel in available serial samples except in nonsurvivors who exhibited delayed vRNA clearance in LRT samples. Plasma vRNA measurement may offer a practical surrogate of LRT vRNA burden in critically ill patients, especially early after ICU admission.

RATIONALE: Lymphopenia is common in severe coronavirus disease (COVID-19), yet the immune mechanisms are poorly understood. As inflammatory cytokines are increased in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, we hypothesized a role in contributing to reduced T-cell numbers. OBJECTIVES: We sought to characterize the functional SARS-CoV-2 T-cell responses in patients with severe versus recovered, mild COVID-19 to determine whether differences were detectable. METHODS: Using flow cytometry and single-cell RNA sequence analyses, we assessed SARS-CoV-2-specific responses in our cohort. MEASUREMENTS AND MAIN RESULTS: In 148 patients with severe COVID-19, we found lymphopenia was associated with worse survival. CD4(+) lymphopenia predominated, with lower CD4(+)/CD8(+) ratios in severe COVID-19 compared with patients with mild disease (P < 0.0001). In severe disease, immunodominant CD4(+) T-cell responses to Spike-1 (S1) produced increased in vitro TNF-alpha (tumor necrosis factor-alpha) but demonstrated impaired S1-specific proliferation and increased susceptibility to activation-induced cell death after antigen exposure. CD4(+) TNF-alpha(+) T-cell responses inversely correlated with absolute CD4(+) counts from patients with severe COVID-19 (n = 76; R = - 0.797; P < 0.0001). In vitro TNF-alpha blockade, including infliximab or anti-TNF receptor 1 antibodies, strikingly rescued S1-specific CD4 (+) T-cell proliferation and abrogated S1-specific activation-induced cell death in peripheral blood mononuclear cells from patients with severe COVID-19 (P < 0.001). Single-cell RNA sequencing demonstrated marked downregulation of type-1 cytokines and NFKB signaling in S1-stimulated CD4(+) cells with infliximab treatment. We also evaluated BAL and lung explant CD4(+) T cells recovered from patients with severe COVID-19 and observed that lung T cells produced higher TNF-alpha compared with peripheral blood mononuclear cells. CONCLUSIONS: Together, our findings show CD4(+) dysfunction in severe COVID-19 is TNF-alpha/TNF receptor 1-dependent through immune mechanisms that may contribute to lymphopenia. TNF-alpha blockade may be beneficial in severe COVID-19.

IMPORTANCEThe effectiveness of monoclonal antibodies (mAbs), casirivimab and imdevimab, and sotrovimab, for patients with mild to moderate COVID-19 from the Delta variant is unknown.OBJECTIVETo evaluate the effectiveness of mAbs for the Delta variant compared to no treatment, and the comparative effectiveness between mAbs.DESIGN, SETTING, AND PARTICIPANTSTwo parallel studies among patients who met Emergency Use Authorization criteria for mAbs from July 14, 2021 to September 29, 2021: i.) prospective observational cohort study comparing mAb treatment to no mAb treatment and, ii.) Bayesian adaptive randomized trial comparing the effectiveness of casirivimab-imdevimab versus sotrovimab. In the observational study, we compared eligible patients who received mAb at an outpatient infusion center at UPMC, to nontreated patients with a positive SARS-CoV-2 test. In the comparative effectiveness trial, we randomly allocated casirivimab-imdevimab or sotrovimab to patients presenting to infusion centers and emergency departments, per system therapeutic interchange policy.EXPOSUREIntravenous mAb per their EUA criteria.MAIN OUTCOMES AND MEASURESFor the observational study, risk ratio estimates for hospitalization or death by 28 days were compared between mAb treatment to no mAb treatment using propensity matched models. For the comparative effectiveness trial, the primary outcome was hospital-free days (days alive and free of hospital) within 28 days, where patients who died were assigned -1 day) in a Bayesian cumulative logistic model, adjusted for treatment location, age, sex, and time. Inferiority was defined as a 99% posterior probability of an odds ratio RESULTSAmong 3,558 patients receiving mAb, the mean age was 54 (SD 18 years), 1,511 (43%) were treated in an infusion center, and 450 (13%) were hospitalized or died by day 28. In propensity matched models, mAb treatment was associated with reduced risk of hospitalization or death compared to no treatment (risk ratio (RR)=0.40, 95% CI: 0.28–0.57). Both casirivimab and imdevimab (RR=0.31, 95% CI: 0.20–0.50), and sotrovimab (RR=0.60, 95% CI: 0.37–1.00) reduced hospitalization or death compared to no mAb treatment. Among patients allocated randomly to casirivimab and imdevimab (n=2,454) or sotrovimab (n=1,104), the median hospital-free days were 28 (IQR 28–28) for both groups, 28-day mortality was 0.5% (n=12) and 0.6% (n=7), and hospitalization by day 28 was 12% (n=291) and 12% (n=140), respectively. Compared to casirivimab and imdevimab, the median adjusted odds ratio for hospital-free days was 0.88 (95% credible interval, 0.70–1.11) for sotrovimab. This odds ratio yielded 86% probability of inferiority of sotrovimab versus casirivimab and imdevimab, and 79% probability of equivalence.CONCLUSIONS AND RELEVANCEIn non-hospitalized patients with mild to moderate COVID-19 due to the Delta variant, casirivimab and imdevimab and sotrovimab were both associated with a reduced risk of hospitalization or death. The comparative effectiveness of mAbs appeared similar, though prespecified criteria for statistical inferiority or equivalence were not met.TRIAL REGISTRATIONClinicalTrials.gov: NCT04790786Key PointsQuestionIn non-hospitalized patients with mild to moderate COVID-19 due to the Delta variant, what is the effectiveness of monoclonal antibodies (mAb) compared to no treatment, and what is the comparative effectiveness between mAb?FindingsAmong 3,069 patients, mAb treatment (casirivimab and imdevimab or sotrovimab) was associated with reduced risk of hospitalization or death by 28 days compared to no treatment (risk ratio=0.40, 95% CI: 0.28–0.57). In a Bayesian randomized comparative effectiveness trial of casirivimab and imdevimab vs. sotrovimab in 3,558 patients, the median hospital–free days were 28 days for both groups. Compared to casirivimab-imdevimab, the median adjusted odds ratio for hospital-free days was 0.88 (95% credible interval, 0.70–1.11) for sotrovimab, an 86% probability of inferiority of sotrovimab versus casirivimab and imdevimab, and 79% probability of equivalence.MeaningIn non-hospitalized patients with mild to moderate COVID-19 due to the Delta variant, casirivimab and imdevimab and sotrovimab were associated with reduced risk of hospitalization or death compared to no treatment. The comparative effectiveness of mAbs appeared similar, though prespecified criteria for statistical inferiority or equivalence were not met.

While there have been extensive analyses characterizing cellular and humoral responses across the severity spectrum in COVID-19, predictors of outcomes within severe COVID-19 remain to be comprehensively elucidated. Recently, we identified divergent monocyte states as predictors of outcomes within severe COVID-19, but corresponding humoral profiles of risk have not been delineated. Furthermore, the nature of antibodies (Abs) directed against viral antigens beyond the spike protein or endemic coronavirus antigens and their associations with disease severity and outcomes remain poorly defined. We performed deep molecular profiling of Abs directed against a wide range of antigenic specificities in severe COVID-19 patients admitted to the ICU. The profiles consisted of canonical (S, RBD, N) and non-canonical (orf3a, orf8, nsp3, nps13 and M) antigenic specificities. Notably, multivariate machine learning (ML) models, generated using profiles of Abs directed against canonical or non-canonical antigens, were equally discriminative of recovery and mortality COVID-19 outcomes. In both ML models, survivors were associated with increased virus-specific IgA and IgG3 antibodies and with higher antigen-specific antibody galactosylation. Intriguingly, pre-pandemic healthy controls had cross-reactive Abs directed against nsp13 which is a conserved protein in other alpha and beta coronaviruses. Notably, higher levels of nsp13-specific IgA antibodies were associated with recovery in severe COVID-19. In keeping with these findings, a model built on Ab profiles for endemic coronavirus antigens was also predictive of COVID-19 outcome bifurcation, with higher levels of IgA and IgG3 antibodies against OC43 S and NL63 S being associated with survival. Our results suggest the importance of Abs targeting non-canonical SARS-CoV-2 antigens as well as those directed against endemic coronaviruses in favorable outcomes of severe COVID-19.

This collaborative meta-analysis was supported by the Swiss National Science Foundation and the Laura and John Arnold Foundation (grant supporting the post-doctoral fellowship at the Meta-Research Innovation Center at Stanford (METRICS), Stanford University). The funders had no role in the design of this collaborative meta-analysis; in the collection, analysis, and interpretation of data; or in the report writing., We would like to express our warm gratitude to all participating patients and convalescent plasma donors. We thank Katja Suter and Sina Ullrich, University of Basel, for their administrative assistance. For their helpful contribution to individual trials, we thank Erica Wood, Iain Gosbell, Richard Charlewood, Thomas Hills, Veronica Hoad, Kristina Kairaitis, Aikaj Jindal, John Gerrard, Hong Foo, Adam Stewart, and Nanette Trask (ASCOT trial); Amalia Bravo-Lindoro, Ral Carrillo-Esper, Karla Maldonado-Silva, Catalina Casillas-Suárez, Orlando Carrillo-Torres, Sandra Murrieta, Elizabeth Diaz-Padilla, Eli Omar Zavaleta, Yadira Bejar-Ramirez, and Evelyn Cortina-de la Rosa (CPC-SARS trial); Sheri Renaud, Roel Rolando-Almario, and Jacqueline Day (NCT04385199 trial); Sandra Tingsgrd, MD, Karen Brorup Heje Pedersen, MD, Michaela Tinggaard, MD, Louise Thorlacius-Ussing, MD, Clara Lundetoft Clausen, MD, Nichlas Hovmand, MD, Simone Bastrup Israelsen, MD, Cecilie Leding, MD, Katrine Iversen, MD, Maria Engel Miller, MD, Hkon Sandholdt, MSc biostatistician (CCAP-2 trial). On behalf of the IRCT20200310046736N1 trial, we thank the Khuzestan Blood Transfusion Organization for specialized assistance in the preparation and maintenance of plasma samples. On behalf of the NCT04332835 trial, we thank all the members of the "PC-COVID-19 Group" at the Clinica del Occidente and Hospital Universitario Mayor Mederi in Bogota, and Clinica CES in Medellin. On behalf of the NCT04403477 trial, we thank Miles Carroll for his support regarding the antibody testing in Bangladesh. The Co-CLARITY team would like to extend their gratitude to the Department of Science and Technology Philippine Council for Health Research and Development and the UP-Philippine General Hospital for all their support in the setting up and conduct of the trial. For helpfully communicating details of their trial, we thank members of the PlasmAr trial, NCT04359810 trial (Max O´Donnell), NCT04468009 trial, and CTRI/2020/05/025299 trial. Support for title page creation and format was provided by AuthorArranger, a tool developed at the National Cancer Institute (https://www.cancer.gov/)., During the conduct of the study, the following is reported: Dr. Berry reports being employee with ownership role at Berry Consultants (receives payments for statistical modeling and design of REMAP-CAP). Dr. Castillo reports grants from DOST PCHRD. Dr. Daly reports grants from Medical Research Future Fund (Australian Govt) and RBWH. Dr. Denkinger reports grants from German Ministry for Education and Research. Dr. Dumagay reports grants from Philippine Council for Health Research and Development. Dr. Dunachie reports grants from UK Department of Health and Social Care, grants from UK National Institute of Health Research. Dr. Gauiran reports grants from Department of Science and Technology—Philippine Council for Health Research and Development. Dr. Gordon reports grants from NIHR, grants from NIHR Research Professorship (RP-2015-06-18), and non-financial support from NIHR Clinical Research Network. Dr. Higgins reports grants from NHMRC and from the Minderoo Foundation. Dr. Hills reports grants from Health Research Council of New Zealand. Dr. Holm reports grants from Swedish Government Funds for Clinical Research (ALF). Dr. Janssen and Dr. Müller-Tidow report grants from the Federal Ministry of Education and Research in Germany (BMBF) to the RECOVER clinical trial. Dr. Krapp reports grants from Department of Foreign Affairs, Trade, and Development of Canada, grants from Fundación Telefónica del Perú. Dr. J. Lim reports grants from the Department of Science and Technology, Philippine Council for Health Research and Development. Dr. Lucero reports grants from Philippine Council for Health Research and Development. Dr Manrique reports economic support from Grupo ISA Intercolombia for the project development of trial NCT04332835. Drs. McQuilten and Wood report grants from Medical Research Future Fund. Dr. McVerry reports grants from The Pittsburgh Foundation, Translational Breast Cancer Research Consortium, and from UPMC Learning While Doing Program. Mr. Mouncey reports grants from National Institute for Health Research and from the European Union FP7: PREPARE. Dr. Najdovski reports payment from KUL Leuven to Belgian Red Cross for supply of convalescent plasma. Dr. Nichol reports grants from Health Research Board of Ireland. Dr. D. Roberts reports grants from the National Institute for Health (UKRIDHSC COVID-19 Rapid Response Rolling Call—Grant Reference Number COV19-RECPLAS) and the European Commission (SUPPORT-E #101015756). Dr. Rowan reports grants from the European Commission and from the UK National Institute for Health Research. Dr. Shankar-Hari reports grants from National Institute for Health Research UK, grants from UKRI-National Institute for Health Research UK. Dr. Turgeon reports grants from Canadian Institutes of Health Research. Dr. Venkatesh reports grants from Baxter. Dr. Webb reports grants from National Health and Medical Research Council, grants from Minderoo Foundation. Dr. Zacharowski reports grants from EU Horizon 2020. The ASCOT trial team (Drs Bowen, Daly, Davis, Denholm, Hammond, Jha, L. Lim, McQuilten, Molton, Morpeth, O’Sullivan, Paterson, Perry, Price, Rees, Roberts, Rogers, Sasadeusz, Snelling, Tong, Venkatesh, Wood) is funded by grants from from Royal Brisbane and Women’s Hospital Foundation, Pratt Foundation, Minderoo Foundation, BHP Foundation, Hospital Research Foundation, Macquarie Group Foundation, Health Research Council of New Zealand, Australian Partnership for Preparedness Research on Infectious Disease Emergencies (APPRISE), and the collection and supply of convalescent plasma was conducted within Lifeblood’s funding arrangements. The CONFIDENT trial is funded by the Belgian KCE (blood establishments received payment for the convalescent plasma supplied in the clinical trial). REMAP-CAP was supported in part by funding from UKRIDHSC COVID-19 Rapid Response Rolling Call (Grant Reference Number COV19-RECPLAS). Collection of convalescent plasma for REMAP-CAP was funded by the Department of Health and Social Care, UK. The IRCT20200310046736N1 trial was supported by the Ahvaz Jundishapur University of Medical Sciences (Grant No. R.AJUMS.REC.1399.003, Dr. Pouladzadeh). The PC-COVID-19 Group is supported by the Universidad del Rosario, IDCBIS, ISA Group and Suramericana (Colombia). Outside the submitted work, the following is reported: Dr. Axfors reports postdoctoral grants from the Knut and Alice Wallenberg Foundation, Uppsala University, the Swedish Society of Medicine, the Blanceflor Foundation, and the Sweden-America Foundation. Dr. Aomar reports personal fees from SOBI, GEDEON RICHTER, and GSK. Dr. Benfield reports grants from Novo Nordisk Foundation, Simonsen Foundation, Lundbeck Foundation, Kai Hansen Foundation, Erik and Susanna Olesen’s Charitable Fund; grants and personal fees from GSK, Pfizer, Gilead; and personal fees from Boehringer Ingelheim, MSD, and Pentabase ApS. Dr. Estcourt reports being an investigator on the RECOVERY trial. Dr. Gordon reports personal fees from GlaxoSmithKline, Bristol Myers Squibb, and 30 Respiratory. Dr. Jha reports grants and personal fees from Baxter Healthcare, personal fees from Astra Zeneca, grants from NephroPlus. Dr. Laterre reports personal fees from Adrenomed. Dr. McVerry reports grants from NIH/NHLBI and Bayer Pharmaceuticals, Inc. Dr. Mondragon reports financial activities outside the submitted work (employment at Johnson & Johnson). Dr. Perry reports partner being employed at CSL and owning shares in CSL. Dr. Paterson reports involvement with ALLIANCE trial of COVID-19 treatments. Dr. J. Roberts reports other COVID-19 related trials (in different patient groups): tocilizumab in ICU patients; hydroxychloroquine dosing in ICU patients; planned study of remdesivir pharmacokinetics in patients during expanded access program; and in silico evaluation of ivermectin dosing. Dr Sasadeusz reports grants from various Pharma companies including Gilead Sciences, Abvvie, Merck, and Takeda. Dr. Zacharowski reports personal fees from Biotest AG, CSL Behring, GE Heathcare, and is President of the ESAIC., Background: Convalescent plasma has been widely used to treat COVID-19 and is under investigation in numerous randomized clinical trials, but results are publicly available only for a small number of trials. The objective of this study was to assess the benefits of convalescent plasma treatment compared to placebo or no treatment and all-cause mortality in patients with COVID-19, using data from all available randomized clinical trials, including unpublished and ongoing trials (Open Science Framework, https://doi.org/10.17605/OSF.IO/GEHFX). Methods: In this collaborative systematic review and meta-analysis, clinical trial registries (ClinicalTrials.gov, WHO International Clinical Trials Registry Platform), the Cochrane COVID-19 register, the LOVE database, and PubMed were searched until April 8, 2021. Investigators of trials registered by March 1, 2021, without published results were contacted via email. Eligible were ongoing, discontinued and completed randomized clinical trials that compared convalescent plasma with placebo or no treatment in COVID-19 patients, regardless of setting or treatment schedule. Aggregated mortality data were extracted from publications or provided by investigators of unpublished trials and combined using the Hartung–Knapp–Sidik–Jonkman random effects model. We investigated the contribution of unpublished trials to the overall evidence. Results: A total of 16,477 patients were included in 33 trials (20 unpublished with 3190 patients, 13 published with 13,287 patients). 32 trials enrolled only hospitalized patients (including 3 with only intensive care unit patients). Risk of bias was low for 29/33 trials. Of 8495 patients who received convalescent plasma, 1997 died (23%), and of 7982 control patients, 1952 died (24%). The combined risk ratio for all-cause mortality was 0.97 (95% confidence interval: 0.92; 1.02) with between-study heterogeneity not beyond chance (I2 = 0%). The RECOVERY trial had 69.8% and the unpublished evidence 25.3% of the weight in the meta-analysis. Conclusions: Convalescent plasma treatment of patients with COVID-19 did not reduce all-cause mortality. These results provide strong evidence that convalescent plasma treatment for patients with COVID-19 should not be used outside of randomized trials. Evidence synthesis from collaborations among trial investigators can inform both evidence generation and evidence application in patient care., Amalia Bravo-Lindoro, BHP Foundation, Blanceflor Foundation, Department of Foreign Affairs, Trade, and Development of Canada, Eli Omar Zavaleta, Erik and Susanna Olesen’s Charitable Fund, Federal Ministry of Education and Research in Germany, Fundación Telefónica del Perú, IDCBIS, ISA Group and Suramericana, Kai Hansen Foundation, Katja Suter and Sina Ullrich, Khuzestan Blood Transfusion Organization, Macquarie Group Foundation, Medical Research Future Fund, NephroPlus, RBWH, Roel Rolando-Almario NCT04385199, Royal Brisbane, Sheri Renaud, Simonsen Foundation, UKRI-National Institute for Health Research UK, UKRIDHSC COV19-RECPLAS, UP-Philippine General Hospital CTRI/2020/05/025299, NCT04359810, NCT04468009, Women’s Hospital Foundation, National Institutes of Health, National Heart, Lung, and Blood Institute, Pittsburgh Foundation, Pfizer, Baxter International, Stanford University, Gilead Sciences, National Institute on Handicapped Research RP-2015-06-18, Meso Scale Diagnostics, Universität Basel, Laura and John Arnold Foundation, Health Research Board, Pratt Foundation, Canadian Institutes of Health Research, National Institute for Health Research, Department of Health and Social Care, European Commission 101015756, National Health and Medical Research Council, Department of Science and Technology, Ministry of Science and Technology, India, Health Research Council of New Zealand, Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, Sweden-America Foundation, Bundesministerium für Bildung und Forschung, Lundbeckfonden, Knut och Alice Wallenbergs Stiftelse, Seventh Framework Programme, Ahvaz Jundishapur University of Medical Sciences, Université Pierre et Marie Curie, Uppsala Universitet, Horizon 2020, Svenska Läkaresällskapet, Universidad del Rosario, Pharmaceuticals Bayer, Novo Nordisk Fonden, Department of Science and Technology, Philippines, Philippine Council for Health Research and Development, Minderoo Foundation

ObjectivesTo reliably quantify the radiographic severity of COVID-19 pneumonia with the Radiographic Assessment of Lung Edema (RALE) score on clinical chest X-rays among inpatients and examine the prognostic value of baseline RALE scores on COVID-19 clinical outcomes.SettingHospitalised patients with COVID-19 in dedicated wards and intensive care units from two different hospital systems.Participants425 patients with COVID-19 in a discovery data set and 415 patients in a validation data set.Primary and secondary outcomesWe measured inter-rater reliability for RALE score annotations by different reviewers and examined for associations of consensus RALE scores with the level of respiratory support, demographics, physiologic variables, applied therapies, plasma host–response biomarkers, SARS-CoV-2 RNA load and clinical outcomes.ResultsInter-rater agreement for RALE scores improved from fair to excellent following reviewer training and feedback (intraclass correlation coefficient of 0.85 vs 0.93, respectively). In the discovery cohort, the required level of respiratory support at the time of CXR acquisition (supplemental oxygen or non-invasive ventilation (n=178); invasive-mechanical ventilation (n=234), extracorporeal membrane oxygenation (n=13)) was significantly associated with RALE scores (median (IQR): 20.0 (14.1–26.7), 26.0 (20.5–34.0) and 44.5 (34.5–48.0), respectively, pConclusionsWith a reproducible method to measure radiographic severity in COVID-19, we found significant associations with clinical and physiologic severity, host inflammation and clinical outcomes. The incorporation of radiographic severity assessments in clinical decision-making may provide important guidance for prognostication and treatment allocation in COVID-19.

Background: Influenza is a global cause of morbidity and mortality and a significant risk for a future pandemic infection. Host hyperinflammation, similar to that seen in COVID-19, may occur in response to influenza virus pneumonia, with Janus kinase (JAK) signalling and proinflammatory cytokines Interleukin (IL)-1 and IL-6 involved. Immune modulation treatment of hospitalised and critically ill COVID-19 patients, including with IL-6 and JAK inhibitors, has been found to be beneficial. Significant interest exists in the use of immunomodulatory agents targeting these pathways in the treatment of severe influenza pneumonia. Methods: We conducted a review with both systematic and narrative methods to assess whether, in patients with severe influenza pneumonia, treatment with immunomodulatory agents targeting IL-1, IL-6 or JAK signalling, in comparison to no immune modulation, is beneficial and improves clinical outcomes. Results: Our systematic search screened 5409 records and found no randomised controlled trials of IL-1, IL-6 or JAK immunomodulatory agents in patients with severe influenza pneumonia. To support this systematic search, we provide a narrative review of the biological rationale, previous use of these agents, including in hospitalised patients with COVID-19, and an overview of their safety profiles. Conclusions: Although immune modulation has proven successful in treating hospitalised and critically ill patients with COVID-19 and a biological rationale exists for testing these agents in influenza, no agents targeting IL-1, IL-6 or JAK signalling have been assessed in randomised controlled trials of patients with severe influenza pneumonia. This highlights a significant evidence gap.

Background: The advent of culture-independent, next-generation DNA sequencing has led to discovery of distinct lung bacterial communities. Studies of lung microbiome taxonomy often reveal only subtle differences between health and disease, but microbial host response may distinguish members of similar communities in different populations. Magnetic-activated cell sorting has been applied to the gut microbiome to identify numbers and types of bacteria eliciting a humoral response. We adapted this technique to examine populations of immunoglobulin-bound bacteria and investigate the lung microbiota in Human Immunodeficiency Virus (HIV) as a representative disease.Methods: 42 people living with HIV and 22 HIV-uninfected individuals underwent bronchoalveolar lavage. We separated immunoglobulin G-bound bacteria using magnetic-activated cell sorting and sequenced the 16S rRNA gene on the Illumina MiSeq platform. We analyzed microbial sequencing data and quantified cytokines and bacterial rRNA copy numbers from bronchoalveolar lavage. Results: Immunoglobulin G-bound bacteria were detectable in the healthy lung microbiota. Comparison of raw bronchoalveolar lavage by HIV status showed no significant taxonomic differences, but the immunoglobulin-bound lung microbiota differed by HIV status with greater abundance of Pseudomonas in people living with HIV. Lung cytokine levels were also higher in people living with HIV, which correlated with increased quantity of immunoglobulin G-bound bacteria. Conclusions: We report a novel application of magnetic-activated cell sorting to identify immunoglobulin G-bound bacteria in the lung. This technique identified distinct bacterial communities which differed in composition from raw bronchoalveolar lavage, revealing differences in health and disease not detected by traditional analyses. Cytokine response was also associated with differential immunoglobulin binding of lung bacteria, suggesting functional importance of these communities.

BackgroundNeutralizing monoclonal antibodies (mAb) targeting SARS-CoV-2 decrease hospitalization and death in patients with mild to moderate Covid-19. Yet, their clinical use is limited, and comparative effectiveness is unknown.MethodsWe present the first results of an ongoing, learning health system adaptive platform trial to expand mAb treatment to all eligible patients and evaluate the comparative effectiveness of available mAbs. The trial launched March 10, 2021. Results are reported as of June 25, 2021 due to the U.S. federal decision to pause distribution of bamlanivimab-etesevimab; patient follow-up concluded on July 23, 2021. Patients referred for mAb who met Emergency Use Authorization criteria were provided a random mAb allocation of bamlanivimab, bamlanivimab-etesevimab, or casirivimab-imdevimab with a therapeutic interchange policy. The primary outcome was hospital-free days (days alive and free of hospital) within 28 days, where patients who died were assigned -1 day. The primary analysis was a Bayesian cumulative logistic model of all patients treated at an infusion center or emergency department, adjusting for treatment location, age, sex, and time. Inferiority was defined as a 99% posterior probability of an odds ratio < 1. Equivalence was defined as a 95% posterior probability that the odds ratio is within a given bound.ResultsPrior to trial launch, 3.1% (502) of 16,345 patients who were potentially eligible by an automated electronic health record (EHR) screen received mAb. During the trial period, 23.2% (1,201) of 5,173 EHR-screen eligible patients were treated, a 7.5-fold increase. After including additional referred patients from outside the health system, a total of 1,935 study patients received mAb therapy (128 bamlanivimab, 885 bamlanivimab-etesevimab, 922 casirivimab-imdevimab). Mean age ranged from 55 to 57 years, half were female (range, 53% to 54%), and 17% were Black (range, 12% to 19%). Median hospital–free days were 28 (IQR, 28 to 28) for each mAb group. Hospitalization varied between groups (bamlanivimab, 12.5%; bamlanivimab-etesevimab, 14.7%, casirivimab-imdevimab, 14.3%). Relative to casirivimab-imdevimab, the median adjusted odds ratios were 0.58 (95% credible interval (CI), 0.30 to 1.16) and 0.94 (95% CI, 0.72 to 1.24) for the bamlanivimab and bamlanivimab-etesevimab groups, respectively. These odds ratios yielded 91% and 94% probabilities of inferiority of bamlanivimab versus bamlanivimab-etesevimab and casirivimab-imdevimab respectively, and an 86% probability of equivalence between bamlanivimab-etesevimab and casirivimab-imdevimab, at the prespecified odds ratio bound of 0.25. Twenty-one infusion-related adverse events occurred in 0% (0/128), 1.4% (12/885), and 1.0% (9/922) of patients treated with bamlanivimab, bamlanivimab-etesevimab, and casirivimab-imdevimab, respectively.ConclusionIn non-hospitalized patients with mild to moderate Covid-19, bamlanivimab, compared to bamlanivimab-etesevimab and casirivimab-imdevimab, resulted in 91% and 94% probabilities of inferiority with regards to odds of improvement in hospital-free days within 28 days. There was an 86% probability of equivalence between bamlanivimab-etesevimab and casirivimab-imdevimab at an odds ratio bound of 0.25. However, the trial was unblinded early due to federal distribution decisions, and no mAb met prespecified criteria for statistical inferiority or equivalence. (ClinicalTrials.gov, NCT04790786).

IntroductionRapid, continuous implementation of credible scientific findings and regulatory approvals is often slow in large, diverse health systems. The COVID-19 pandemic created a new threat to this common “slow to learn and adapt” model in healthcare. We describe how UPMC committed to a rapid learning health system (LHS) model to respond to the COVID-19 pandemic.MethodsAn observational cohort study was conducted among 11,429 hospitalized patients from 22 hospitals (PA, NY) with a primary diagnosis of COVID-19 infection (March 19, 2020 – June 6, 2021). Sociodemographic and clinical data were captured from UPMC electronic medical record (EMR) systems. Patients were grouped into four time-defined patient “waves” based on nadir of daily hospital admissions, with wave 3 (September 20, 2020 – March 10, 2021) split at its zenith due to high volume with steep acceleration and deceleration. Outcomes included changes in clinical practice (e.g., use of corticosteroids, antivirals, and other therapies) in relation to timing of internal system analyses, scientific publications, and regulatory approvals, along with 30-day rate of mortality over time.ResultsMean (SD) daily number of hospital admissions was 26 (28) with a maximum 7-day moving average of 107 patients. System-wide implementation of the use of dexamethasone, remdesivir, and tocilizumab occurred within days of release of corresponding seminal publications and regulatory actions. After adjustment for differences in patient clinical profiles over time, each month of hospital admission was associated with an estimated 5% lower odds of 30-day mortality (adjusted OR = 0.95, 95% confidence interval: 0.92 – 0.97, p < .001).ConclusionsIn our large LHS, near real-time changes in clinical management of COVID-19 patients happened promptly as scientific publications and regulatory approvals occurred throughout the pandemic. Alongside these changes, patients with COVID-19 experienced lower adjusted 30-day mortality following hospital admission over time.

Background Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral RNA (vRNA) is detected in the bloodstream of some patients with coronavirus disease 2019 (COVID-19), but it is not clear whether this RNAemia reflects viremia (ie, virus particles) and how it relates to host immune responses and outcomes. Methods SARS-CoV-2 vRNA was quantified in plasma samples from observational cohorts of 51 COVID-19 patients including 9 outpatients, 19 hospitalized (non–intensive care unit [ICU]), and 23 ICU patients. vRNA levels were compared with cross-sectional indices of COVID-19 severity and prospective clinical outcomes. We used multiple imaging methods to visualize virions in plasma. Results SARS-CoV-2 vRNA was detected in plasma of 100%, 52.6%, and 11.1% of ICU, non-ICU, and outpatients, respectively. Virions were detected in plasma pellets using electron tomography and immunostaining. Plasma vRNA levels were significantly higher in ICU > non-ICU > outpatients (P 6000 copies/mL was strongly associated with mortality (hazard ratio, 10.7). Levels of vRNA were significantly associated with several inflammatory biomarkers (P Conclusions Visualization of virus particles in plasma indicates that SARS-CoV-2 RNAemia is due, at least in part, to viremia. The levels of SARS-CoV-2 RNAemia correlate strongly with disease severity, patient outcome, and specific inflammatory biomarkers but not with neutralizing antibody titers.

Supplemental Digital Content is available in the text., OBJECTIVES: Hyper- and hypoinflammatory subphenotypes discovered in patients with acute respiratory distress syndrome predict clinical outcomes and therapeutic responses. These subphenotypes may be important in broader critically ill patient populations with acute respiratory failure regardless of clinical diagnosis. We investigated subphenotyping with latent class analysis in an inclusive population of acute respiratory failure, derived a parsimonious model for subphenotypic predictions based on a small set of variables, and examined associations with clinical outcomes. DESIGN: Prospective, observational cohort study. SETTING: Single-center, academic medical ICU. PATIENTS: Mechanically ventilated patients with acute respiratory failure. MEASUREMENTS AND MAIN RESULTS: We included 498 patients with acute respiratory failure (acute respiratory distress syndrome: 143, at-risk for acute respiratory distress syndrome: 198, congestive heart failure: 37, acute on chronic respiratory failure: 23, airway protection: 61, and multifactorial: 35) in our derivation cohort and measured 10 baseline plasma biomarkers. Latent class analysis considering clinical variables and biomarkers determined that a two-class model offered optimal fit (23% hyperinflammatory subphenotype). Distribution of hyperinflammatory subphenotype varied among acute respiratory failure etiologies (acute respiratory distress syndrome: 31%, at-risk for acute respiratory distress syndrome: 27%, congestive heart failure: 22%, acute on chronic respiratory failure 0%, airway protection: 5%, and multifactorial: 14%). Hyperinflammatory patients had higher Sequential Organ Failure Assessment scores, fewer ventilator-free days, and higher 30- and 90-day mortality (all p < 0.001). We derived a parsimonious model consisting of angiopoietin-2, soluble tumor necrosis factor receptor-1, procalcitonin, and bicarbonate and classified subphenotypes in a validation cohort (n = 139). Hyperinflammatory patients (19%) demonstrated higher levels of inflammatory biomarkers not included in the model (p < 0.01) and worse outcomes. CONCLUSIONS: Host-response subphenotypes are observable in a heterogeneous population with acute respiratory failure and predict clinical outcomes. Simple, biomarker-based models can offer prognostic enrichment in patients with acute respiratory failure. The differential distribution of subphenotypes by specific etiologies of acute respiratory failure indicates that subphenotyping may be more relevant in patients with hypoxemic causes of acute respiratory failure and not in patients intubated for airway protection or acute on chronic decompensation.