American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · Feb 2020
Losartan Rescues Inflammation-related Mucociliary Dysfunction in Relevant Models of Cystic Fibrosis.
Rationale: Despite therapeutic progress in treating cystic fibrosis (CF) airway disease, airway inflammation with associated mucociliary dysfunction remains largely unaddressed. Inflammation reduces the activity of apically expressed large-conductance Ca2+-activated and voltage-dependent K+ (BK) channels, critical for mucociliary function in the absence of CFTR (CF transmembrane conductance regulator). Objectives: To test losartan as an antiinflammatory therapy in CF using CF human bronchial epithelial cells and an ovine model of CF-like airway disease. ⋯ Expanding on a validated and published nongenetic, CF-like sheep model, ewes inhaled CFTRinh172 and neutrophil elastase for 3 days, which resulted in prolonged tracheal mucus velocity reduction, mucus hyperconcentration, and increased TGF-β1. Nebulized losartan rescued both mucus transport and mucus hyperconcentration and reduced TGF-β1. Conclusions: Losartan effectively reversed CF- and inflammation-associated mucociliary dysfunction, independent of its angiotensin receptor blockade.
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Am. J. Respir. Crit. Care Med. · Feb 2020
General and Organ Fat Assessed by Magnetic Resonance Imaging and Respiratory Outcomes in Childhood.
Rationale: Obesity has been implicated as a pathogenic factor in asthma, but the underlying role of general and organ fat is unclear. Objectives: We hypothesized that organ fat, rather than the total fat mass, increases the risk of asthma. Methods: In a population-based prospective cohort study among 5,421 children aged 10 years, we measured general fat including body mass index and fat mass index by dual-energy X-ray absorptiometry, and organ fat including subcutaneous fat index, visceral fat index, pericardial fat index, and liver fat fraction by magnetic resonance imaging. ⋯ Higher visceral fat index, independent of fat mass index, was associated with higher FVC (z-score difference [95% CI], 0.07 [0.03 to 0.10]), lower FEV1/FVC (z-score difference [95% CI], -0.05 [-0.09 to -0.01]), and higher risk of asthma (odds ratio, 1.20; 95% CI, 1.01 to 1.43 per SD score increase). No other organ fat measures were independently associated with lung function or asthma. Conclusions: The obesity-asthma link is driven mainly by visceral fat, independent of total fat mass; therefore, abdominal fat might contribute to asthma development.
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Am. J. Respir. Crit. Care Med. · Feb 2020
Respiratory Syncytial Virus Disease Severity Is Associated with Distinct CD8+ T-Cell Profiles.
Rationale: Respiratory syncytial virus (RSV) causes significant morbidity and mortality in infants worldwide. Although T-helper type 2 (Th2) cell pathology is implicated in severe disease, the mechanisms underlying the development of immunopathology are incompletely understood. Objectives: We aimed to identify local immune responses associated with severe RSV in infants. ⋯ Patients with greater frequencies of Tc1, CD8+ T cells expressing IL-17 (Tc17), and CD4+ T cells expressing IL-17 (Th17) had shorter durations of hospitalization. Conclusions: Severe RSV disease was associated with distinct T-cell profiles. Tc1, Tc17, and Th17 were associated with shorter hospital stay and may play a protective role, whereas Tc2 cells may play a previously underappreciated role in pathology.
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Am. J. Respir. Crit. Care Med. · Feb 2020
Systematic Literature Review of Systemic Corticosteroid Use for Asthma Management.
Systemic corticosteroid use to manage uncontrolled asthma and its associated healthcare burden may account for important health-related adverse effects. We conducted a systematic literature review to investigate the real-world extent and burden of systemic corticosteroid use in asthma. We searched MEDLINE and Embase databases to identify English-language articles published in 2010-2017, using search terms for asthma with keywords for oral corticosteroids and systemic corticosteroids. ⋯ Greater oral/systemic corticosteroid exposure was also associated with increased costs and healthcare resource use. This review provides a comprehensive overview of oral/systemic corticosteroid use and associated adverse events for patients with all degrees of asthma severity and exposure duration. We report that oral/systemic corticosteroid use is prevalent in asthma management, and the risks of acute and chronic complications increase with the cumulative oral corticosteroid dosage.