Susceptibility to chronic obstructive pulmonary disease (COPD) beyond cigarette smoking is incompletely understood, although several genetic variants associated with COPD are known to regulate airway branch development. We demonstrate that in vivo central airway branch variants are present in 26.5% of the general population, are unchanged over 10 y, and exhibit strong familial aggregation. The most common airway branch variant is associated with COPD in two cohorts ( = 5,054), with greater central airway bifurcation density, and with emphysema throughout the lung. The second most common airway branch variant is associated with COPD among smokers, with narrower airway lumens in all lobes, and with genetic polymorphisms within the gene. We conclude that central airway branch variation, readily detected by computed tomography, is a biomarker of widely altered lung structure with a genetic basis and represents a COPD susceptibility factor.

Patients with multimorbidity and complex health care needs are usually vulnerable elders with several concomitant advanced chronic diseases. Our research aim was to evaluate differences in patterns of multimorbidity by gender in this population and their possible prognostic implications, measured as in-hospital mortality, 1-month readmissions, and 1-year mortality. We focused on a cohort of elderly patients with well-established multimorbidity criteria admitted to a specific unit for chronic complex-care patients. Multimorbidity criteria, the Charlson, PROFUND and Barthel indexes, and the Pfeiffer test were collected prospectively during their stays. A total of 843 patients (49.2% men) were included, with a median age of 84 [interquartile range (IQR) 79-89] years. The women were older, with greater functional dependence [Barthel index: 40 (IQR:10-65) vs. 60 (IQR: 25-90)], showed more cognitive deterioration [Pfeiffer test: 5 (IQR:1-9) vs. 1 (0-6)], and had worse scores on the PROFUND index [15 (IQR:9-18) vs. 11.5 (IQR: 6-15)], all p <0.0001, while men had greater comorbidity measured with the Charlson index [5 (IQR: 3-7) vs. 4 (IQR: 3-6); p = 0.002]. In the multimorbidity criteria scale, heart failure, autoimmune diseases, dementia, and osteoarticular diseases were more frequent in women, while ischemic heart disease, chronic respiratory diseases, and neoplasms predominated in men. In the analysis of grouped patterns, neurological and osteoarticular diseases were more frequent in females, while respiratory and cancer predominated in males. We did not find gender differences for in-hospital mortality, 1-month readmissions, or 1-year mortality. In the multivariate analysis age, the Charlson, Barthel and PROFUND indexes, along with previous admissions, were independent predictors of 1-year mortality, while gender was non-significant. The Charlson and PROFUND indexes predicted mortality during follow-up more accurately in men than in women (AUC 0.70 vs. 0.57 and 0.74 vs. 0.62, respectively), with both p<0.001. In conclusion, our study shows differing patterns of multimorbidity by gender, with greater functional impairment in women and more comorbidity in men, although without differences in the prognosis. Moreover, some of these prognostic indicators had differing accuracy for the genders in predicting mortality.

Emphysema, a component of chronic obstructive pulmonary disease (COPD), is characterized by irreversible alveolar destruction that results in a progressive decline in lung function. This alveolar destruction is caused by cigarette smoke, the most important risk factor for COPD. Only 15%‐20% of smokers develop COPD, suggesting that unknown factors contribute to disease pathogenesis. We postulate that the aryl hydrocarbon receptor (AHR), a receptor/transcription factor highly expressed in the lungs, may be a new susceptibility factor whose expression protects against COPD. Here, we report that Ahr‐deficient mice chronically exposed to cigarette smoke develop airspace enlargement concomitant with a decline in lung function. Chronic cigarette smoke exposure also increased cleaved caspase‐3, lowered SOD2 expression, and altered MMP9 and TIMP‐1 levels in Ahr‐deficient mice. We also show that people with COPD have reduced expression of pulmonary and systemic AHR, with systemic AHR mRNA levels positively correlating with lung function. Systemic AHR was also lower in never‐smokers with COPD. Thus, AHR expression protects against the development of COPD by controlling interrelated mechanisms involved in the pathogenesis of this disease. This study identifies the AHR as a new, central player in the homeostatic maintenance of lung health, providing a foundation for the AHR as a novel therapeutic target and/or predictive biomarker in chronic lung disease.

Background:There is a paucity of information on patient characteristics associated with enrolment under voluntary programs (e.g. incentive payments) implemented within fee-for-service systems. We explored patient characteristics associated with enrolment under these programs in British Columbia and Quebec. Methods:We used linked administrative data and a cross-sectional design to compare people aged 40 years or more enrolled under voluntary programs to those who were eligible but not enrolled. We examined 2 programs in Quebec (enrolment of vulnerable patients with qualifying conditions [implemented in 2003] and enrolment of the general population [2009]) and 3 in BC (Chronic disease incentive [2003], Complex care incentive [2007] and enrolment of the general population [A GP for Me, 2013]). We used logistic regression to estimate the odds of enrolment by neighbourhood income, rural versus urban residence, previous treatment for mental illness, previous treatment for substance use disorder and use of health care services before program implementation, controlling for characteristics linked to program eligibility. Results:In Quebec, we identified 1 569 010 people eligible for the vulnerable enrolment program (of whom 505 869 [32.2%] were enrolled within the first 2 yr of program implementation) and 2 394 923 for the general enrolment program (of whom 352 380 [14.7%] were enrolled within the first 2 yr). In BC, we identified 133 589 people eligible for the Chronic disease incentive, 47 619 for the Complex care incentive and 1 349 428 for A GP for Me; of these, 60 764 (45.5%), 28 273 (59.4%) and 1 066 714 (79.0%), respectively, were enrolled within the first 2 years. The odds of enrolment were higher in higher-income neighbourhoods for programs without enrolment criteria (adjusted odds ratio [OR] comparing highest to lowest quintiles 1.21 [95% confidence interval (CI) 1.20-1.23] in Quebec and 1.67 [95% CI 1.64-1.69] in BC) but were similar across neighbourhood income quintiles for programs with health-related eligibility criteria. The odds of enrolment by urban versus rural location varied by program. People treated for substance use disorders had lower odds of enrolment in all programs (adjusted OR 0.60-0.72). Compared to people eligible but not enrolled, those enrolled had similar or higher numbers of primary care visits and longitudinal continuity of care in the year before enrolment.Interpretation: People living in lower-income neighbourhoods and those treated for substance use disorders were less likely than people in higher-income neighbourhoods and those not treated for such disorders to be enrolled in programs without health-related eligibility criteria. Other strategies are needed to promote equitable access to primary care.

Membrane-associated RING-CH-1 (March1) is a member of the March family of E3 ubiquitin ligases. March1 downregulates cell surface expression of MHC II and CD86 by targeting them to lysosomal degradation. Given the key roles of MHC class II and CD86 in T cell activation and to get further insights into the development of allergic inflammation, we asked whether March1 deficiency exacerbates or attenuates features of allergic asthma in mice. Herein, we used an acute model of allergy to compare the asthmatic phenotype of March1-deficient and -sufficient mice immunized with ovalbumin (OVA) and later challenged by intranasal instillation of OVA in the lungs. We found that eosinophilic inflammation in airways and lung tissue was similar between WT and March1−/− allergic mice, whereas neutrophilic inflammation was significant only in March1−/− mice. Airway hyperresponsiveness as well as levels of IFN-γ, IL-13, IL-6, and IL-10 was lower in the lungs of asthmatic March1−/− mice compared to WT, whereas lung levels of TNF-α, IL-4, and IL-5 were not significantly different. Interestingly, in the serum, levels of total and ova-specific IgE were reduced in March1-deficient mice as compared to WT mice. Taken together, our results demonstrate a role of March1 E3 ubiquitin ligase in modulating allergic responses.

Within-city ultrafine particle (UFP) concentrations vary sharply since they are influenced by various factors. We developed prediction models for short-term UFP exposures using street-level images collected by a camera installed on a vehicle rooftop, paired with air quality measurements conducted during a large-scale mobile monitoring campaign in Toronto, Canada. Convolutional neural network models were trained to extract traffic and built environment features from images. These features, along with regional air quality and meteorology data were used to predict short-term UFP concentration as a continuous and categorical variable. A gradient boost model for UFP as a continuous variable achieved R 2 = 0.66 and RMSE = 9391.8#/cm3 (mean values for 10-fold cross-validation). The model predicting categorical UFP achieved accuracies for “Low” and “High” UFP of 77 and 70%, respectively. The presence of trucks and other traffic parameters were associated with higher UFPs, and the spatial distribution of elevated short-term UFP followed the distribution of single-unit trucks. This study demonstrates that pictures captured on urban streets, associated with regional air quality and meteorology, can adequately predict short-term UFP exposure. Capturing the spatial distribution of high-frequency short-term UFP spikes in urban areas provides crucial information for the management of near-road air pollution hot spots.

CD4 T cells express the epidermal growth factor (EGF) receptor ligand, heparin-binding EGF (HB-EGF), with no defined immuno-pathophysiological function. Therefore, we wished to elucidate the function of HB-EGF synthesized by CD4 T cells in the context of allergic pulmonary inflammation and the asthma surrogate, airway hyperresponsiveness, in a murine acute model of asthma. In this study, we show how knocking out HB-EGF expression in CD4 T cells in vivo attenuates IL-5 synthesis in the lung that is accompanied by diminished eosinophilic inflammation and airway hyperresponsiveness. HB-EGF coimmunoprecipitates with the transcriptional repressor B cell lymphoma 6 (Bcl-6) in CD4 T cells. Knocking out HB-EGF in CD4 T cells resulted in increased Bcl-6 binding to the IL-5 gene and decreased IL-5 mRNA expression. Thus, these findings suggest an immunoregulatory function for intrinsic HB-EGF expressed by CD4 T cells in TH2 inflammation and airway dysfunction by modulating IL-5 expression via binding to and inhibiting the repressive function of Bcl-6.

Spirometry remains essential for the diagnosis of airway obstruction. Nevertheless, its performance in elderly hospitalized patients with multimorbidity can be difficult. The aim of this study is to assess the utility of the COPD-6 portable device in this population. We included all patients hospitalized for exacerbation of chronic diseases in a medical ward specialized in the care of multimorbidity patients, between September 2017 and May 2018. A questionnaire including sociodemographic, cognitive and functional impairment, among other variables, was completed the last day of admission. Subsequently, patients attempted to perform three valid respiratory manoeuvres with the COPD-6 device and then conventional spirometry. A total of 184 patients were included (mean age of 79.61 years, 55% men). Forty-seven (25.54%) patients were able to perform complete spirometric manoeuvres and 99 (53.8%) could perform a valid FEV1/FEV6 determination. The inability to perform a valid spirometry was related with the patient’s age, functional physical disability, cognitive impairment or the presence of delirium or dysphagia during admission. Only 9% of patients with a Mini Mental Cognitive Examination (MMEC) lower than 24 points could perform a valid spirometry. Of the patients with an MMEC < 24 points and unable to perform spirometry, 34% were able to complete the FEV1/FEV6 manoeuvres. No differences were found in the Charlson index, multimorbidity scale, number of domiciliary drugs, or length of stay between those patients able and those not able to perform respiratory manoeuvres. The agreement between the values for FEV1 measured with COPD-6 and those observed in the spirometry was good (r: 0.71; p<0.0001). Inability to perform a valid spirometry during hospitalization in elderly patients with multimorbidity is frequent and related with functional and cognitive impairment. FEV1/FEV6 determination using the COPD-6 portable device allows an important percentage of the patients with limitations to complete spirometric measurement.