American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · Jul 2020
Effect of Lung Protective Ventilation in Organ Donors on Lung Procurement and Recipient Survival.
Rationale: Previous studies have shown that a lung-protective strategy, which aims at minimizing ventilator-induced lung injury (with low Vt/high positive end-expiratory pressure as the main pillars), in selected potential organ donors after brain death increased lung eligibility and procurement. Objectives: This prospective nationwide cohort study aimed to evaluate the impact of lung-protective ventilation (PV) in nonselected donors on lung procurement and recipient survival after lung transplantation. Methods: We included all reported donors aged 18-70 years after brain death without a lung recovery contraindication and with at least one organ recovered between January 2016 and December 2017. ⋯ One-year survival did not differ between recipients of lungs from donors with and without PV (82.7%, 95% CI 76.0-87.8% vs. 82.3%, 95% CI 78.5-85.4%; P = 0.94). Conclusions: The use of lung PV in nonselected donors may increase lung procurement. One-year survival did not differ between recipients of lungs from donors with PV or from those without PV.
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Am. J. Respir. Crit. Care Med. · Jul 2020
Assessing the Accuracy of a Deep Learning Method to Risk Stratify Indeterminate Pulmonary Nodules.
Rationale: The management of indeterminate pulmonary nodules (IPNs) remains challenging, resulting in invasive procedures and delays in diagnosis and treatment. Strategies to decrease the rate of unnecessary invasive procedures and optimize surveillance regimens are needed. Objectives: To develop and validate a deep learning method to improve the management of IPNs. ⋯ Using 5% and 65% malignancy thresholds defining low- and high-risk categories, the overall net reclassifications in the validation cohorts for cancers and benign nodules compared with the Mayo model were 0.34 (Vanderbilt) and 0.30 (Oxford) as a rule-in test, and 0.33 (Vanderbilt) and 0.58 (Oxford) as a rule-out test. Compared with traditional risk prediction models, the Lung Cancer Prediction Convolutional Neural Network was associated with improved accuracy in predicting the likelihood of disease at each threshold of management and in our external validation cohorts. Conclusions: This study demonstrates that this deep learning algorithm can correctly reclassify IPNs into low- or high-risk categories in more than a third of cancers and benign nodules when compared with conventional risk models, potentially reducing the number of unnecessary invasive procedures and delays in diagnosis.
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Am. J. Respir. Crit. Care Med. · Jul 2020
Increased Alternative Complement Pathway Function and Improved Survival During Critical Illness.
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 activity, during critical illness. Objectives: We examined the function and key components of the alternative complement pathway in a series of critically ill patients and in a mouse pneumonia model. ⋯ Conversely, depletion of AP factors, or AH50 less than median, impaired in vitro serum control of KP that was restored by adding healthy serum. Cfb-/- mice demonstrated increased extrapulmonary dissemination and serum inflammatory markers after intratracheal KP infection compared with wild type. Conclusions: Elevated AP function is associated with improved survival during critical illness, possibly because of enhanced immune capacity.
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Am. J. Respir. Crit. Care Med. · Jul 2020
Lung Function Trajectories Leading to Chronic Obstructive Pulmonary Disease as Predictors of Exacerbations and Mortality.
Rationale: Chronic obstructive pulmonary disease (COPD) can develop not only through a lung function trajectory dominated by an accelerated decline of FEV1 from normal maximally attained FEV1 in early adulthood (normal maximally attained FEV1 trajectory) but also through a trajectory with FEV1 below normal in early adulthood (low maximally attained FEV1 trajectory). Objectives: To test whether the long-term risk of exacerbations and mortality differs between these two subtypes of COPD. Methods: The cohort included 1,170 young adults enrolled in the Copenhagen City Heart Study during the 1970s and 1980s. ⋯ Measurements and Main Results: From 2001 until 2018, we observed 139 severe exacerbations of COPD and 215 deaths, of which 55 were due to nonmalignant respiratory disease. In Cox models, there was no difference with regard to risk of severe exacerbations between the two trajectories, but individuals with normal maximally attained FEV1 had an increased risk of nonmalignant respiratory disease mortality (using inverse probability of censoring weighting with adjusted hazard ratio [HR], 6.20; 95% confidence interval [CI], 2.09-18.37; P = 0.001) and all-cause mortality (adjusted HR, 1.93; 95% CI, 1.14-3.26; P = 0.01) compared with individuals with low maximally attained FEV1. Conclusions: COPD developed through normal maximally attained FEV1 trajectory is associated with an increased risk of respiratory and all-cause mortality compared with COPD developed through low maximally attained FEV1 trajectory.
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Am. J. Respir. Crit. Care Med. · Jul 2020
Expression of the SARS-CoV-2 ACE2 Receptor in the Human Airway Epithelium.
Rationale: Infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease (COVID-19), a predominantly respiratory illness. The first step in SARS-CoV-2 infection is binding of the virus to ACE2 (angiotensin-converting enzyme 2) on the airway epithelium. ⋯ Measurements and Main Results:1) ACE2 is expressed similarly in the trachea and LAE, with lower expression in the SAE; 2) in the SAE, ACE2 is expressed in basal, intermediate, club, mucus, and ciliated cells; 3) ACE2 is upregulated in the SAE by smoking, significantly in men; 4) levels of miR-1246 expression could play a role in ACE2 upregulation in the SAE of smokers; and 5) ACE2 is expressed in airway epithelium differentiated in vitro on air-liquid interface cultures from primary airway basal stem/progenitor cells; this can be replicated using LAE and SAE immortalized basal cell lines derived from healthy nonsmokers. Conclusions:ACE2, the gene encoding the receptor for SARS-CoV-2, is expressed in the human airway epithelium, with variations in expression relevant to the biology of initial steps in SARS-CoV-2 infection.