American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · Apr 2021
Comparative StudyAirspace Macrophages and Monocytes Exist in Transcriptionally Distinct Subsets in Healthy Adults.
Rationale: Macrophages are the most abundant immune cell in the alveoli and small airways and are traditionally viewed as a homogeneous population during health. Whether distinct subsets of airspace macrophages are present in healthy humans is unknown. Single-cell RNA sequencing allows for examination of transcriptional heterogeneity between cells and between individuals. ⋯ Resident macrophages make up the largest population and include novel subsets defined by inflammatory and metal-binding profiles. Monocyte-like cells within the airspaces are transcriptionally aligned with circulating blood cells and include a rare population defined by expression of cell-matrix interaction genes. This study is the first to delineate the conserved heterogeneity of airspace immune cells during health and identifies two previously unrecognized macrophage subsets.
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Am. J. Respir. Crit. Care Med. · Apr 2021
Comparative StudyContribution of Individual and Neighborhood Factors to Racial Disparities in Respiratory Outcomes.
Rationale: Black adults have worse health outcomes compared with white adults in certain chronic diseases, including chronic obstructive pulmonary disease (COPD). Objectives: To determine to what degree disadvantage by individual and neighborhood socioeconomic status (SES) may contribute to racial disparities in COPD outcomes. Methods: Individual and neighborhood-scale sociodemographic characteristics were determined in 2,649 current or former adult smokers with and without COPD at recruitment into SPIROMICS (Subpopulations and Intermediate Outcome Measures in COPD Study). ⋯ Even after accounting for both individual and neighborhood SES factors, Black individuals continued to have increased severe exacerbation risk and persistently worse CT outcomes (emphysema, air trapping, and airway wall thickness). Conclusions: Disadvantages by individual- and neighborhood-level SES each partly explain disparities in respiratory outcomes between Black individuals and white individuals. Strategies to narrow the gap in SES disadvantages may help to reduce race-related health disparities in COPD; however, further work is needed to identify additional risk factors contributing to persistent disparities.
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Am. J. Respir. Crit. Care Med. · Apr 2021
Lung Clearance Index to Track Acute Respiratory Events in School-age Children with Cystic Fibrosis.
Rationale: The lung clearance index (LCI) is responsive to acute respiratory events in preschool children with cystic fibrosis (CF), but its utility to identify and manage these events in school-age children with CF is not well defined. Objectives: To describe changes in LCI with acute respiratory events in school-age children with CF. Methods: In a multisite prospective observational study, the LCI and FEV1 were measured quarterly and during acute respiratory events. ⋯ Neither LCI nor FEV1 recovered to baseline values at the next follow-up visit. Conclusions: In school-age children with CF, the LCI is a sensitive measure to assess lung function worsening with acute respiratory events and incomplete recovery at follow-up. In combination, the LCI and FEV1 capture a higher proportion of events with functional impairment.