Daily Respiratory Research Analysis

Allergic asthma arises from complex genetic and environmental interactions. Analysis of a population-wide registry revealed that infants hospitalized for human respiratory syncytial virus (RSV) bronchiolitis who are born to asthmatic parents have a markedly increased risk of developing asthma. To model this interaction, neonatal mice infected with pneumonia virus of mice (PVM), an RSV analog, before house dust mite (HDM) exposure developed amplified type 2 inflammation and asthma-like pathology. Maternal, but not paternal, HDM allergy intensified disease, implicating vertical transmission of an immune risk factor. Mechanistically, neonatal viral infection up-regulated Fc receptors (FcRs) and promoted maturation of type 2 conventional dendritic cells (cDC2s). Maternal allergen-specific immunoglobulin G (IgG), transferred via neonatal Fc receptor (FcRn), enhanced Fc gamma receptor (FcγR)-mediated allergen uptake and T helper 2 (T

BACKGROUND: Acute respiratory distress syndrome (ARDS) is a life-threatening condition with significant heterogeneity in pathophysiology. The integration of pulmonary edema indices, respiratory mechanics, and gas exchange parameters to define subphenotypes in mechanically ventilated patients with ARDS has not yet been investigated. METHODS: We conducted a post hoc analysis of a prospective observational study with a derivation cohort (n = 111). We applied K-means clustering to identify distinct subphenotypes based on key physiological parameters: pulmonary edema indices, respiratory mechanics, and gas exchange variables. The primary outcome was 28-day mortality. Between-group differences in 28-day mortality were analyzed using the chi-square test. Survival analysis was performed with Kaplan-Meier curves (compared by log-rank test) and multivariable Cox regression to adjust for covariates. Furthermore, we compared the differential responses to prone positioning ventilation among the identified subphenotypes to evaluate its potential interaction effect on mortality. An independent validation cohort (n = 55) was used to confirm the subphenotype classifications and their relationships with clinical outcomes. RESULTS: Unsupervised clustering revealed two distinct subphenotypes. Subphenotype 2, characterized by elevated pulmonary vascular permeability index (PVPI) and ventilation ratio (VR), demonstrated significantly higher 28-day mortality compared to Subphenotype 1 (50.0% vs. 28.2%, p = 0.021). This survival disadvantage was confirmed by Kaplan-Meier analysis (log-rank p = 0.016) and a multivariable Cox regression model (adjusted hazard ratio [HR] 2.263, 95% confidence interval [CI] 1.206-4.245; p = 0.011). Furthermore, a statistically significant interaction was observed between subphenotypes and response to prone positioning for 28-day mortality (p-for-interaction = 0.015). Crucially, the prognostic distinction between subphenotypes and their differential treatment response were consistently replicated in an independent validation cohort. CONCLUSIONS: Using unsupervised machine learning, this study identified two distinct ARDS subphenotypes characterized by divergent profiles in pulmonary edema, respiratory mechanics, and gas exchange. These subphenotypes were associated with significantly different clinical outcomes and exhibited a differential response to prone positioning therapy. Future research should prioritize the execution of large-scale, multicenter, randomized controlled trials to validate these findings and advance the clinical implementation of precision medicine in the management of ARDS.

UNLABELLED: Mucosal immunity plays a crucial role in protection against respiratory viruses. However, the mechanisms underlying mucosal responses and their impact on COVID-19 outcomes are not well understood, as mucosal immunity is compartmentalized and not always reflected in the bloodstream. This study examined primary immune responses in 584 mucosal and blood specimens collected over a month from previously naïve adults and children with COVID-19. Various laboratory techniques were utilized to quantify and characterize viral RNA, antigens, antibodies, and cytokines in the samples, including PCR, sequencing, ELISA, and Luminex. Comprehensive system analysis uncovered distinctive characteristics associated with mild COVID-19 disease progression, including markedly early and elevated induction of mucosal IFN-α and IP-10, followed by increased levels of IL-1RA and IgG. Individuals experiencing mild COVID-19 demonstrated synchronized mucosal and systemic immune responses, with a gradual increase in antibody production that resulted in enhanced neutralization potency, potentially conferring greater protection against future infection. In contrast, individuals with moderate and severe COVID-19 exhibited diminished IFN-α and IP-10 responses and dysregulated mucosal and systemic immune responses marked by rapid and robust yet less effective humoral immunity, potentially driven by high antigen and cytokine levels in both compartments. Collectively, these findings underscore that early mucosal immune responses may play a pivotal role in attenuating COVID-19 disease severity. Additionally, they suggest that primary mucosal immune responses to novel viruses influence clinical outcomes, providing critical insights necessary for developing prognostic indicators, treatments, and mucosal vaccines that confer protection against SARS-CoV-2 and emerging respiratory pathogens. IMPORTANCE: This research is crucial for understanding the intricate interplay between mucosal immunity and SARS-CoV-2 infection. By examining the distinct systemic and mucosal immune responses during COVID-19, this study addresses the critical gap in our knowledge of how the body defends itself at the primary site of infection: the respiratory mucosa. The findings shed light on the specific characteristics of the mucosal immune response, including the roles of different antibody isotypes, immune cells, and local factors in controlling viral entry and replication. Furthermore, because this study focuses on