Clinical and biologic profiles of patients with acute respiratory distress syndrome by prevalence of chronic obstructive pulmonary disease or emphysema; a cohort study.

Introduction: Acute respiratory distress syndrome (ARDS) is characterized by diffuse lung injury. The impact of pre-existing chronic obstructive pulmonary disease (COPD) or emphysema on ARDS pathogenesis is not well characterized.

Methods: Secondary analysis of ARDS patients enrolled in the Acute Lung Injury Registry and Biospecimen Repository at the University of Pittsburgh between June 2012 and September 2021.

Impact of variable titer COVID-19 convalescent plasma and recipient SARS-CoV2-specific humoral immunity on survival in hospitalized patients.

COVID-19 convalescent plasma (CCP) was one of the first therapies to receive emergency use authorization for management of COVID-19. We assessed the effectiveness of CCP in a propensity-matched analysis, and whether the presence of antibodies in the recipient at the time of treatment or the titer of antibodies in the administered CCP influenced clinical effectiveness. In an inpatient population within a single large health system, a total of 290 CCP patients were matched to 290 controls.

Antibiotic use during influenza infection augments lung eosinophils that impair immunity against secondary bacterial pneumonia.

A leading cause of mortality after influenza infection is the development of a secondary bacterial pneumonia. In the absence of a bacterial superinfection, prescribing antibacterial therapies is not indicated but has become a common clinical practice for those presenting with a respiratory viral illness. In a murine model, we found that antibiotic use during influenza infection impaired the lung innate immunologic defenses toward a secondary challenge with methicillin-resistant Staphylococcus aureus (MRSA).

Emergence of high-level aztreonam-avibactam and cefiderocol resistance following treatment of an NDM-producing bloodstream isolate exhibiting reduced susceptibility to both agents at baseline.

Background: Cefiderocol (FDC) or ceftazidime-avibactam with aztreonam (CZA-ATM) are frontline agents for New Delhi metallo-β-lactamase (NDM)-producing Enterobacterales; however, clinical data are scarce, and mechanisms of treatment-emergent resistance are ill-defined. Our objectives were to characterize serial isolates and stool microbiota from a liver transplant recipient with NDM-producing bacteraemia.

Methods: Isolates collected pre- and post-CZA-ATM treatment underwent broth microdilution susceptibility testing and whole-genome sequencing.

Subphenotypes of self-reported symptoms and outcomes in long COVID: a prospective cohort study with latent class analysis.

Objective: To characterise subphenotypes of self-reported symptoms and outcomes (SRSOs) in postacute sequelae of COVID-19 (PASC).

Design: Prospective, observational cohort study of subjects with PASC.

Setting: Academic tertiary centre from five clinical referral sources.

Glucocorticoid use in acute respiratory failure from pulmonary causes and association with early changes in the systemic host immune response.

Background: Glucocorticoids are commonly used in patients with or at-risk for acute respiratory distress syndrome (ARDS), but optimal use remains unclear despite well-conducted clinical trials. We performed a secondary analysis in patients previously enrolled in the Acute Lung Injury and Biospecimen Repository at the University of Pittsburgh. The primary aim of our study was to investigate early changes in host response biomarkers in response to real-world use of glucocorticoids in patients with acute respiratory failure due to ARDS or at-risk due to a pulmonary insult.

Lung Epithelium Releases Growth Differentiation Factor 15 in Response to Pathogen-mediated Injury.

GDF15 (growth differentiation factor 15) is a stress cytokine with several proposed roles, including support of stress erythropoiesis. Higher circulating GDF15 levels are prognostic of mortality during acute respiratory distress syndrome, but the cellular sources and downstream effects of GDF15 during pathogen-mediated lung injury are unclear. We quantified GDF15 in lower respiratory tract biospecimens and plasma from patients with acute respiratory failure.

Trajectories of Host-Response Subphenotypes in Patients With COVID-19 Across the Spectrum of Respiratory Support.

Background: Hospitalized patients with severe COVID-19 follow heterogeneous clinical trajectories, requiring different levels of respiratory support and experiencing diverse clinical outcomes. Differences in host immune responses to SARS-CoV-2 infection may account for the heterogeneous clinical course, but we have limited data on the dynamic evolution of systemic biomarkers and related subphenotypes. Improved understanding of the dynamic transitions of host subphenotypes in COVID-19 may allow for improved patient selection for targeted therapies.

A common single nucleotide polymorphism is associated with inflammation and critical illness outcomes.

Acute inflammation is heterogeneous in critical illness and predictive of outcome. We hypothesized that genetic variability in novel, yet common, gene variants contributes to this heterogeneity and could stratify patient outcomes. We searched algorithmically for significant differences in systemic inflammatory mediators associated with any of 551,839 SNPs in one derivation (n = 380 patients with blunt trauma) and two validation (n = 75 trauma and n = 537 non-trauma patients) cohorts.

Noninvasive diagnosis of secondary infections in COVID-19 by sequencing of plasma microbial cell-free DNA.

Secondary infection (SI) diagnosis in severe COVID-19 remains challenging. We correlated metagenomic sequencing of plasma microbial cell-free DNA (mcfDNA-Seq) with clinical SI assessment, immune response, and outcomes. We classified 42 COVID-19 inpatients as microbiologically confirmed-SI (Micro-SI, n = 8), clinically diagnosed-SI (Clinical-SI, n = 13, i.

Robust airway microbiome signatures in acute respiratory failure and hospital-acquired pneumonia.

Respiratory microbial dysbiosis is associated with acute respiratory distress syndrome (ARDS) and hospital-acquired pneumonia (HAP) in critically ill patients. However, we lack reproducible respiratory microbiome signatures that can increase our understanding of these conditions and potential treatments. Here, we analyze 16S rRNA sequencing data from 2,177 respiratory samples collected from 1,029 critically ill patients (21.

Prognostic Insights from Longitudinal Multicompartment Study of Host-Microbiota Interactions in Critically Ill Patients.

Critical illness can disrupt the composition and function of the microbiome, yet comprehensive longitudinal studies are lacking. We conducted a longitudinal analysis of oral, lung, and gut microbiota in a large cohort of 479 mechanically ventilated patients with acute respiratory failure. Progressive dysbiosis emerged in all three body compartments, characterized by reduced alpha diversity, depletion of obligate anaerobe bacteria, and pathogen enrichment.

Factor H preserves alternative complement function during ARDS, linked to improved survival.

Background: Effective regulation of complement activation may be crucial to preserving complement function during acute respiratory distress syndrome (ARDS). Factor H is the primary negative regulator of the alternative pathway of complement. We hypothesised that preserved factor H levels are associated with decreased complement activation and reduced mortality during ARDS.

Respiratory Fungal Communities are Associated with Systemic Inflammation and Predict Survival in Patients with Acute Respiratory Failure.

Rationale: Disruption of respiratory bacterial communities predicts poor clinical outcomes in critical illness; however, the role of respiratory fungal communities (mycobiome) is poorly understood.

Objectives: We investigated whether mycobiota variation in the respiratory tract is associated with host-response and clinical outcomes in critically ill patients.

Methods: To characterize the upper and lower respiratory tract mycobiota, we performed rRNA gene sequencing (internal transcribed spacer) of oral swabs and endotracheal aspirates (ETA) from 316 mechanically-ventilated patients.

Distinct profiles of host responses between plasma and lower respiratory tract during acute respiratory failure.

https://bit.ly/40kTdDG.

The upper and lower respiratory tract microbiome in severe aspiration pneumonia.

Uncertainty persists whether anaerobic bacteria represent important pathogens in aspiration pneumonia. In a nested case-control study of mechanically ventilated patients classified as macro-aspiration pneumonia (MAsP, n = 56), non-macro-aspiration pneumonia (NonMAsP, n = 91), and uninfected controls (n = 11), we profiled upper (URT) and lower respiratory tract (LRT) microbiota with bacterial 16S rRNA gene sequencing, measured plasma host-response biomarkers, analyzed bacterial communities by diversity and oxygen requirements, and performed unsupervised clustering with Dirichlet Multinomial Models (DMM). MAsP and NonMAsP patients had indistinguishable microbiota profiles by alpha diversity and oxygen requirements with similar host-response profiles and 60-day survival.