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Objective: Bronchial thermoplasty is an effective intervention to improve respiratory symptoms and to reduce the rate of exacerbations in uncontrolled severe asthma. A reduction in airway smooth muscle is arguably the most widely discussed mechanisms accounting for these clinical benefits. Yet, this smooth muscle reduction should also translate into an impaired response to bronchodilator drugs. A pilot study was designed to address this question. Hypothesis: Thermoplasty decreases the response to a bronchodilator. Methods: Lung functions measured by spirometry and respiratory mechanics measured by oscillometry (tremoFlo, Thorasys) were examined pre- and post-bronchodilator (salbutamol, 400 μg) before and after at least 1 year of thermoplasty in 8 patients (7 women) with uncontrolled severe asthma. For each readout, a two-way ANOVA was used to assess the effect of thermoplasty, salbutamol, and their interaction. All procedures were approved by the IUCPQ Ethics Committee. Data: Consistent with previous studies, thermoplasty yielded no benefits in terms of baseline lung function and respiratory mechanics, despite improving symptoms based on two questionnaires assessing the level of asthma control (Asthma Control Questionnaire – ACQ-5, and Asthma Control Test – ACT-5). The response to salbutamol was not affected by thermoplasty based on spirometric readouts, including forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and FEV1/FVC ratio. However, a significant interaction was observed between thermoplasty and salbutamol for two oscillometric readouts. The reactance of the respiratory system at 5 Hz (Xrs5) increased from -3.2 ±2.6 to -1.9 ± 1.9 cmH2O ·s/L in response to salbutamol pre-thermoplasty, versus from -2.8 ± 2.3 to -2.2 ± 1.9 cmH2O·s/L post-thermoplasty (interaction, p=0.04). Similarly, the reactance area (Ax) decreased from 32.6 ± 29.0 to 12.8 ±18.2 cmH2O/L in response to salbutamol pre-thermoplasty, versus 27.2 ± 29.4 to 15.7 ± 20.1 cmH2O/L post-thermoplasty (interaction, p=0.02). The salbutamol-induced changes in resistance at 5 Hz (Rrs5), resistance at 19 Hz (Rrs19), Rrs5 minus Rrs19, and resonant frequency were not significantly affected by thermoplasty. Summary of results: While spirometry was unable to detect changes in the response to salbutamol caused by thermoplasty, two oscillometric readouts, namely Xrs5 and Ax, confirmed that the bronchodilator response is attenuated post-thermoplasty. Conclusion: Despite its small size, this study demonstrates that thermoplasty attenuates the response to a bronchodilator. We argue that this result is a physiological proof of therapeutic efficacy, consistent with the well-described effect of thermoplasty in reducing the amount of airway smooth muscle. FQSR (Fondation Quebecoise en Sante Respiratoire); Canadian Institutes of Health Research (PJT-387910); FRQS (Fonds de recherche du Quebec - Sante); and Boston Scientific Inc This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Background Bronchial thermoplasty is a device-based treatment for subjects ≥18 years with severe asthma poorly controlled with inhaled corticosteroids and long-acting beta-agonists. The Post-FDA Approval Clinical Trial Evaluating Bronchial Thermoplasty in Severe Persistent Asthma (PAS2) study collected data on severe asthmatics undergoing this procedure. Research Question What are the 5-year efficacy and safety results in severe asthmatics who have undergone bronchial thermoplasty? Study Design and Methods This was a prospective, open-label, observational, multi-center study conducted in the United States and Canada. Subjects aged 18-65, taking inhaled corticosteroids ≥1000μg/day (beclomethasone or equivalent) and long-acting β-agonists ≥80μg/day (salmeterol or equivalent) were included. Severe exacerbations, hospitalization, emergency department visits, and medication usage were evaluated for the 12 months prior to and at years 1-5 post-treatment. Spirometry was evaluated at baseline and at years 1-5 post-treatment. Results 284 subjects were enrolled at 27 centers; 227 subjects (80%) completed 5 years of follow-up. By year 5 post-treatment, the proportion of subjects with severe exacerbations, emergency department visits, and hospitalizations was 42.7%, 7.9%, and 4.8%, respectively, compared to 77.8%, 29.4%, and 16.1% in the 12 months prior to treatment. The proportion of subjects on maintenance oral corticosteroids decreased from 19.4% at baseline to 9.7% at 5 years. Analyses of subgroups based on baseline clinical and biomarker characteristics revealed a statistically significant clinical improvement among all subgroups. Interpretation Five years after treatment, subjects experienced decreases in severe exacerbations, hospitalizations, emergency department visits and corticosteroid exposure. All subgroups demonstrated clinically significant improvement, suggesting that bronchial thermoplasty improves asthma control in different asthma phenotypes.

PDF file - 589K, Probe sets significantly associated with smoking in the discovery set

PDF file - 242K, Table S2. Clinical characteristics of patients in the first replication set (UBC). Table S3. Clinical characteristics of patients in the second replication set (Groningen). Figure S1. Volcano plots showing the impact of smoking, COPD, and lung cancer on gene expression in the lung. Figure S2. Comparison of gene expression recovery following smoking cessation between the discovery set (Laval) and UBC. Figure S3. Comparison of gene expression recovery following smoking cessation between the discovery set (Laval) and Groningen. Figure S4. Expression of SERPIND1 in lung parenchyma of smoker and never-smoker by immunochemistry. Figure S5. Enrichment plot for slowly reversible gene in UBC. Figure S6. Enrichment plot for slowly reversible gene in Groningen

Methods BT10+ was an international, multicentre, follow-up study of participants who were previously enrolled in the AIR, RISA, and AIR2 trials and who had 10 or more years of follow-up since bronchial thermoplasty treatment. Data on patient demographics, quality of life, lung function, CT scans (AIR2 participants only), severe exacerbations, and health-care use during the previous year were collected at the BT10+ 10-year outcomes study visit. The primary effectiveness endpoint was durability of the thermoplasty treatment effect, determined by comparing the proportion of participants who had severe exacerbations during the first and fifth years after bronchial thermoplasty treatment with the proportion of participants who had severe exacerbations during the 12-month period before the BT10+ visit. The primary safety endpoint was the absence of clinically significant post-treatment respiratory image changes after bronchial thermoplasty, defined as bronchiectasis or bronchial stenosis as confirmed by pulmonary volumetric highresolution CT scan at the BT10+ visit (AIR2 participants only). All analyses were done on an intention-to-treat basis. The trial is registered with ClinicalTrials.gov, NCT03243292. The last patient was enrolled on Dec 11, 2018. The last patient completed follow-up on Jan 10, 2019.Findings The BT10+ study enrolled 192 (45%) of the 429 participants who were enrolled in the AIR, RISA, and AIR2 trials. The BT10+ participants comprised 136 who received bronchial thermoplasty (52% of the 260 participants who received bronchial thermoplasty in the original trials), and 56 sham or control participants (33% of 169 from the original trials). 18 (32%) sham or control participants received bronchial thermoplasty after the previous trials concluded. The participants included in BT10+ were followed for 10?8?15?6 years (median 12?1 years) post-treatment. Baseline characteristics were similar between participants enrolled in BT10+ and those not enrolled. Participants treated with bronchial thermoplasty had similar proportions of severe exacerbations at the BT10+ visit (34 [25%] of 136 participants) compared with 1 year (33 [24%] of 135 participants; difference 0?6%, 95% CI ?9?7 to 10?8) and 5 years (28 [22%] of 130 participants; difference 3?5%, ?6?7% to 13?6) after treatment. Quality of life measurements and spirometry were similar between year 1, year 5, and the BT10+ visit. At the BT10+ study visit, pulmonary high-resolution CT scans from AIR2 participants treated with bronchial thermoplasty showed that 13 (13%) of 97 participants had bronchiectasis. When compared with baseline high-resolution CT scans, six (7%) of 89 participants treated with bronchial thermoplasty who did not have bronchiectasis at baseline had developed bronchiectasis after treatment (5 classified as mild, 1 classified as moderate). Participants treated with bronchial thermoplasty after the original study and participants in the sham or control group also had reductions in severe exacerbations at the BT10+ visit compared with baseline.Summary Background Bronchial thermoplasty is an endoscopic treatment for uncontrolled asthma. Previous randomised clinical trials have shown that bronchial thermoplasty reduces severe exacerbations in people with asthma. However, the long-term efficacy and safety of bronchial thermoplasty beyond 5 years is unknown. The BT10+ study aimed to investigate the efficacy and safety of bronchial thermoplasty after 10 or more years of follow-up. Methods BT10+ was an international, multicentre, follow-up study of participants who were previously enrolled in the AIR, RISA, and AIR2 trials and who had 10 or more years of follow-up since bronchial thermoplasty treatment. Data on patient demographics, quality of life, lung function, CT scans (AIR2 participants only), severe exacerbations, and health-care use during the previous year were collected at the BT10+ 10-year outcomes study visit. The primary effectiveness endpoint was durability of the thermoplasty treatment effect, determined by comparing the proportion of participants who had severe exacerbations during the first and fifth years after bronchial thermoplasty treatment with the proportion of participants who had severe exacerbations during the 12-month period before the BT10+ visit. The primary safety endpoint was the absence of clinically significant post-treatment respiratory image changes after bronchial thermoplasty, defined as bronchiectasis or bronchial stenosis as confirmed by pulmonary volumetric high resolution CT scan at the BT10+ visit (AIR2 participants only). All analyses were done on an intention-to-treat basis. The trial is registered with ClinicalTrials.gov, NCT03243292. The last patient was enrolled on Dec 11, 2018. The last patient completed follow-up on Jan 10, 2019. Findings The BT10+ study enrolled 192 (45%) of the 429 participants who were enrolled in the AIR, RISA, and AIR2 trials. The BT10+ participants comprised 136 who received bronchial thermoplasty (52% of the 260 participants who received bronchial thermoplasty in the original trials), and 56 sham or control participants (33% of 169 from the original trials). 18 (32%) sham or control participants received bronchial thermoplasty after the previous trials concluded. The participants included in BT10+ were followed for 10middot8-15middot6 years (median 12middot1 years) post-treatment. Baseline characteristics were similar between participants enrolled in BT10+ and those not enrolled. Participants treated with bronchial thermoplasty had similar proportions of severe exacerbations at the BT10+ visit (34 [25%] of 136 participants) compared with 1 year (33 [24%] of 135 participants; difference 0middot6%, 95% CI -9middot7 to 10middot8) and 5 years (28 [22%] of 130 participants; difference 3middot5%, -6middot7% to 13middot6) after treatment. Quality of life measurements and spirometry were similar between year 1, year 5, and the BT10+ visit. At the BT10+ study visit, pulmonary high-resolution CT scans from AIR2 participants treated with bronchial thermoplasty showed that 13 (13%) of 97 participants had bronchiectasis. When compared with baseline high-resolution CT scans, six (7%) of 89 participants treated with bronchial thermoplasty who did not have bronchiectasis at baseline had developed bronchiectasis after treatment (5 classified as mild, 1 classified as moderate). Participants treated with bronchial thermoplasty after the original study and participants in the sham or control group also had reductions in severe exacerbations at the BT10+ visit compared with baseline.Interpretation Our findings suggest that efficacy of bronchial thermoplasty is sustained for 10 years or more, with an acceptable safety profile. Therefore, bronchial thermoplasty is a long-acting therapeutic option for patients with asthma that remains uncontrolled despite optimised medical treatment. Funding Boston Scientific. Copyright (c) 2021 Elsevier Ltd. All rights reserved.

2-Arachidonoyl-glycerol (2-AG) is an endocannabinoid with anti-inflammatory properties. Blocking 2-AG hydrolysis to enhance CB2 signaling has proven effective in mouse models of inflammation. However, the expression of 2-AG lipases has never been thoroughly investigated in human leukocytes. Herein, we investigated the expression of seven 2-AG hydrolases by human blood leukocytes and alveolar macrophages (AMs) and found the following protein expression pattern: monoacylglycerol (MAG lipase; eosinophils, AMs, monocytes), carboxylesterase (CES1; monocytes, AMs), palmitoyl-protein thioesterase (PPT1; AMs), α/β-hydrolase domain (ABHD6; mainly AMs), ABHD12 (all), ABHD16A (all), and LYPLA2 (lysophospholipase 2; monocytes, lymphocytes, AMs). We next found that all leukocytes could hydrolyze 2-AG and its metabolites derived from cyclooxygenase-2 (prostaglandin E2-glycerol [PGE2-G]) and the 15-lipoxygenase (15-hydroxy-eicosatetraenoyl-glycerol [15-HETE-G]). Neutrophils and eosinophils were consistently better at hydrolyzing 2-AG and its metabolites than monocytes and lymphocytes. Moreover, the efficacy of leukocytes to hydrolyze 2-AG and its metabolites was 2-AG ≥ 15-HETE-G >> PGE2-G for each leukocyte. Using the inhibitors methylarachidonoyl-fluorophosphonate (MAFP), 4-nitrophenyl-4-(dibenzo[d][1,3]dioxol-5-yl(hydroxy)methyl)piperidine-1-carboxylate (JZL184), Palmostatin B, 4′-carbamoylbiphenyl-4-yl methyl(3-(pyridin-4-yl)benzyl)carbamate, N-methyl-N-[[3-(4-pyridinyl)phenyl]methyl]-4′-(aminocarbonyl)[1,1′-biphenyl]-4-yl ester carbamic acid (WWL70), 4′-[[[methyl[[3-(4-pyridinyl)phenyl]methyl]amino]carbonyl]oxy]-[1,1′-biphenyl]-4-carboxylic acid, ethyl ester (WWL113), tetrahydrolipstatin, and ML349, we could not pinpoint a specific hydrolase responsible for the hydrolysis of 2-AG, PGE2-G, and 15-HETE-G by these leukocytes. Furthermore, JZL184, a selective MAG lipase inhibitor, blocked the hydrolysis of 2-AG, PGE2-G, and 15-HETE-G by neutrophils and the hydrolysis of PGE2-G and 15-HETE-G by lymphocytes, two cell types with limited/no MAG lipase. Using an activity-based protein profiling (ABPP) probe to label hydrolases in leukocytes, we found that they express many MAFP-sensitive hydrolases and an unknown JZL184-sensitive hydrolase of ∼52 kDa. Altogether, our results indicate that human leukocytes are experts at hydrolyzing 2-AG and its metabolites via multiple lipases and probably via a yet-to-be characterized 52 kDa hydrolase. Blocking 2-AG hydrolysis in humans will likely abrogate the ability of human leukocytes to degrade 2-AG and its metabolites and increase their anti-inflammatory effects in vivo.

Background Bronchial thermoplasty (BT) is a novel technique used in the treatment of subjects with severe refractory asthma. Radiofrequency is provided to airway walls during bronchoscopy in order to reduce airway remodeling. Several clinical studies have reported an improvement in subjects’ symptoms following BT. However, how BT affects the airway architectures and inflammatory mediators in the airways has not been yet fully elucidated. Methods Fourteen subjects with severe asthma were recruited in this study according to the criteria of ATS severe asthma definition. The study subjects undertook bronchial biopsy during the bronchoscopy procedure at baseline and 6 weeks after the initial BT treatment. The obtained samples were stained with antibodies for α-smooth muscle actin (α-SMA); protein gene product (PGP) 9.5, a specific nerve marker; von Willebrand factor (vWF), a marker for blood vessels; interleukin-17A (IL-17A) and transforming growth factor-β1 (TGF-β1). Results The expression of α-SMA and PGP9.5 were significantly reduced post-BT. There was no significant difference in the number of blood vessels between baseline and post-BT. In addition, BT did not affect the production of IL-17A and TGF-β1 in the airways. The changes in the expression of α-SMA and PGP9.5 had no significant correlation with the improvement of pulmonary function. Conclusion and Clinical Relevance: This study suggests that BT reduces airway smooth muscle mass and the airway innervation without affecting vasculature and the production of inflammatory mediators in the airways of subjects with severe asthma.

Leukotriene B4 (LTB4) plays a prominent role in innate immunity as it induces phagocyte recruitment, the release of antimicrobial effectors, and as it potentiates the ingestion and killing of pathogens. In humans, LTB4 has a short half-life and is rapidly metabolized by leukocytes, notably into 20-OH- and 20-COOH-LTB4 by neutrophils. Although these LTB4 metabolites bind to the BLT1 receptor with high affinity, they activate neutrophils to a much lower extent than LTB4. We thus postulated that LTB4 metabolites could dampen BLT1-mediated responses, therefore limiting the impact of LTB4 on human neutrophil functions. We found that 20-OH-LTB4 and 20-COOH-LTB4 inhibited all of the LTB4-mediated neutrophil responses we tested (migration, degranulation, leukotriene biosynthesis). The potencies of the different compounds at inhibiting LTB4-mediated responses were 20-OH-LTB4 = CP 105,696 (BLT1 antagonist) > > 20-COOH-LTB4 ≥ resolvin E1 (RVE1). In contrast, the fMLP- and IL-8-mediated responses we tested were not affected by the LTB4 metabolites or RVE1. 20-OH-LTB4 and 20-COOH-LTB4 also inhibited the LTB4-mediated migration of human eosinophils but not that induced by 5-KETE. Moreover, using 20-COOH-LTB4, LTB4, and LTB4-alkyne, we show that LTB4 is a chemotactic, rather than a chemokinetic factor for both human neutrophils and eosinophils. In conclusion, our data indicate that LTB4 metabolites and RVE1 act as natural inhibitors of LTB4-mediated responses. Thus, preventing LTB4 ω-oxidation might result in increased innate immunity and granulocyte functions.

Bronchial thermoplasty is a device-based treatment for subjects ≥ 18 years of age with severe asthma poorly controlled with inhaled corticosteroids and long-acting beta-agonists. The Post-FDA Approval Clinical Trial Evaluating Bronchial Thermoplasty in Severe Persistent Asthma (PAS2) study collected data on patients with severe asthma undergoing this procedure.What are the 5-year efficacy and safety results in patients with severe asthma who have undergone bronchial thermoplasty?This was a prospective, open-label, observational, multicenter study conducted in the United States and Canada. Subjects 18 to 65 years of age who were taking inhaled corticosteroids ≥ 1,000 μg/d (beclomethasone or equivalent) and long-acting beta-agonists ≥ 80 μg/d (salmeterol or equivalent) were included. Severe exacerbations, hospitalization, ED visits, and medication usage were evaluated for the 12 months prior to and at years 1 through 5 posttreatment. Spirometry was evaluated at baseline and at years 1 through 5 posttreatment.A total of 284 subjects were enrolled at 27 centers; 227 subjects (80%) completed 5 years of follow-up. By year 5 posttreatment, the proportion of subjects with severe exacerbations, ED visits, and hospitalizations was 42.7%, 7.9%, and 4.8%, respectively, compared with 77.8%, 29.4%, and 16.1% in the 12 months prior to treatment. The proportion of subjects on maintenance oral corticosteroids decreased from 19.4% at baseline to 9.7% at 5 years. Analyses of subgroups based on baseline clinical and biomarker characteristics revealed a statistically significant clinical improvement among all subgroups.Five years after treatment, subjects experienced decreases in severe exacerbations, hospitalizations, ED visits, and corticosteroid exposure. All subgroups demonstrated clinically significant improvement, suggesting that bronchial thermoplasty improves asthma control in different asthma phenotypes.ClinicalTrials.gov; No.: NCT01350336; URL: www.gov.

Severe acute respiratory syndrome coronavirus 2 is responsible for coronavirus disease 2019 (COVID‐19). While COVID‐19 is often benign, a subset of patients develops severe multilobar pneumonia that can progress to an acute respiratory distress syndrome. There is no cure for severe COVID‐19 and few treatments significantly improved clinical outcome. Dexamethasone and possibly aspirin, which directly/indirectly target the biosynthesis/effects of numerous lipid mediators are among those options. Our objective was to define if severe COVID‐19 patients were characterized by increased bioactive lipids modulating lung inflammation. A targeted lipidomic analysis of bronchoalveolar lavages (BALs) by tandem mass spectrometry was done on 25 healthy controls and 33 COVID‐19 patients requiring mechanical ventilation. BALs from severe COVID‐19 patients were characterized by increased fatty acids and inflammatory lipid mediators. There was a predominance of thromboxane and prostaglandins. Leukotrienes were also increased, notably LTB4, LTE4, and eoxin E4. Monohydroxylated 15‐lipoxygenase metabolites derived from linoleate, arachidonate, eicosapentaenoate, and docosahexaenoate were also increased. Finally yet importantly, specialized pro‐resolving mediators, notably lipoxin A4 and the D‐series resolvins, were also increased, underscoring that the lipid mediator storm occurring in severe COVID‐19 involves pro‐ and anti‐inflammatory lipids. Our data unmask the lipid mediator storm occurring in the lungs of patients afflicted with severe COVID‐19. We discuss which clinically available drugs could be helpful at modulating the lipidome we observed in the hope of minimizing the deleterious effects of pro‐inflammatory lipids and enhancing the effects of anti‐inflammatory and/or pro‐resolving lipid mediators.

BACKGROUNDSevere Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) is the infectious agent responsible for Coronavirus disease 2019 (COVID-19). While SARS-CoV-2 infections are often benign, there are also severe COVID-19 cases, characterized by severe bilobar pneumonia that can decompensate to an acute respiratory distress syndrome, notably characterized by increased inflammation and a cytokine storm. While there is no cure against severe COVID-19 cases, some treatments significantly decrease the severity of the disease, notably aspirin and dexamethasone, which both directly or indirectly target the biosynthesis (and effects) of numerous bioactive lipids.OBJECTIVEOur working hypothesis was that severe COVID-19 cases necessitating mechanical ventilation were characterized by increased bioactive lipid levels modulating lung inflammation. We thus quantitated several lung bioactive lipids using liquid chromatography combined to tandem mass spectrometry.RESULTSWe performed an exhaustive assessment of the lipid content of bronchoalveolar lavages from 25 healthy controls and 33 COVID-19 patients necessitating mechanical ventilation. Severe COVID-19 patients were characterized by increased fatty acid levels as well as an accompanying inflammatory lipid storm. As such, most quantified bioactive lipids were heavily increased. There was a predominance of cyclooxygenase metabolites, notably TXB2 >> PGE2 ∼ 12-HHTrE > PGD2. Leukotrienes were also increased, notably LTB4, 20-COOH-LTB4, LTE4, and eoxin E4. 15-lipoxygenase metabolites derived from linoleic, arachidonic, eicosapentaenoic and docosahexaenoic acids were also increased. Finally, yet importantly, specialized pro-resolving mediators, notably lipoxin A4 and the D-series resolvins, were also found at important levels, underscoring that the lipid storm occurring in severe SARS-CoV-2 infections involves pro- and anti-inflammatory lipids.CONCLUSIONSOur data unmask the important lipid storm occurring in the lungs of patients afflicted with severe COVID-19. We discuss which clinically available drugs could be helpful at modulating the lipidome we observed in the hope of minimizing the deleterious effects of pro-inflammatory lipids and enhancing the effects of anti-inflammatory and/or pro-resolving lipids.

To identify susceptibility loci and candidate causal genes of asthma, we performed a genome-wide association study (GWAS) in UK Biobank on a broad asthma definition (n = 56,167 asthma cases and 352,255 controls). We then carried out functional mapping through transcriptome-wide association studies (TWAS) and Mendelian randomization in lung (n = 1,038) and blood (n = 31,684) tissues. The GWAS revealed 72 asthma-associated loci from 116 independent significant variants (PGWAS 20) including a stop-gain mutation in the filaggrin (FLG) gene. The top lung TWAS gene on 17q12-q21 was GSDMB (PTWAS=1.42E-54). Other TWAS genes of interest include TSLP on 5q22, RERE on 1p36, CLEC16A on 16p13, and IL4R on 16p12, which all replicated in GTEx lung (n = 515). A novel risk locus was also revealed by the lung asthma TWAS on 1q23.3 with the putative gene encoding the gamma chain of the high-affinity IgE receptor (FCER1G, PTWAS=2.13E-6), which was also replicated in GTEx lung (PTWAS=3.71E-7). By testing a comprehensive set of cells and tissues, we then demonstrated that the largest fold enrichment of regulatory and functional annotations among asthma-associated variants was in the blood. We mapped 485 eQTL-regulated genes associated with asthma in the blood and 50 of them were shown to be causally associated with asthma by Mendelian randomization. Prioritization of druggable genes revealed known (IL4R, TSLP, IL6, TNFSF4) and potentially new therapeutic targets for asthma.

To identify candidate causal genes of asthma, we performed a genome-wide association study (GWAS) in UK Biobank on a broad asthma definition (n = 56,167 asthma cases and 352,255 controls). We then carried out functional mapping through transcriptome-wide association studies (TWAS) and Mendelian randomization in lung (n = 1,038) and blood (n = 31,684) tissues. The GWAS reveals 72 asthma-associated loci from 116 independent significant variants (PGWAS, Kim Valette et al. perform a genomic study on asthma integrating genome-wide association study, functional mapping using lung and blood transcriptome-wide profiles, as well as Mendelian randomization. They show candidate causal genes expressed in lung and blood tissues that are putative therapeutic targets for asthma.

Aim: This study aimed to characterize DNA methylation (DNA-me) in promoter region of IL33, IL1RL1 and CCL26 in asthma and their impacts on transcriptional activity in bronchial epithelial cells (BECs). Patients & methods: We performed bis-pyrosequencing, quantitative real-time PCR and sequencing in BECs from ten asthmatic and ten control individuals. Results: We detected lower DNA-me levels of IL33 and CCL26 in asthmatic than control BECs. No correlation was found between methylation and expression levels. Interestingly, carriers of a mutative allele in a haplotype within the promoter of IL33 had a lower IL33 DNA-me level and CCL26 gene expression correlated with eosinophil count. Conclusion: These findings highlight the importance of investigating both epigenetic and genetic mechanisms in understanding the epithelial immune response in asthma.

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Background Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection can lead to a variety of clinical outcomes ranging from the absence of symptoms to severe acute respiratory disease and ultimately death. A feature of patients with severe Coronavirus disease 19 (COVID-19) is the abundance of inflammatory cytokines in the blood. Elevated levels of cytokine are predictive of infection severity and clinical outcome. In contrast, studies aimed at defining the driving forces behind the inflammation in lungs of severed COVID-19 subjects remain scarce. Objective To analyze and compare the plasma and bronchoalveolar lavages (BALs) of patients with severe COVID-19 (n=45) for the presence of cytokines and lipid mediators of inflammation (LMI). Methods Cytokines were measured using Luminex multiplex assay and LMI measured using LC-MS/MS. Results We reveal high concentrations of numerous cytokines/chemokines/LMI in BALs of patients with severe COVID-19. Among the 13 most abundant mediators in BALs, 11 were chemokines with CXCL1 and CXCL8 being 200 times more abundant than IL-6 and TNF-α. Eicosanoids were also elevated in lungs of severe COVID-19 subjects. Consistent with the presence chemotactic molecules, BALs were enriched for neutrophils, lymphocytes and eosinophils. Inflammatory cytokines/LMI in plasma showed limited correlations with those present in BALs, arguing that circulating inflammatory molecules may not be a reliable proxy of the inflammation occurring in the lungs of severe COVID-19 patients. Conclusions Our findings indicate that lungs hyperinflammation of severe COVID-19 patients is fueled by excessive production of chemokines and eicosanoids. Therapeutic strategies to dampen inflammation in COVID-19 patients should be tailored accordingly., Graphical abstract

Background The Airways Disease Endotyping for Personalized Therapeutics (ADEPT) study profiled patients with mild, moderate, and severe asthma and nonatopic healthy control subjects. Objective We explored this data set to define type 2 inflammation based on airway mucosal IL-13–driven gene expression and how this related to clinically accessible biomarkers. Methods IL-13–driven gene expression was evaluated in several human cell lines. We then defined type 2 status in 25 healthy subjects, 28 patients with mild asthma, 29 patients with moderate asthma, and 26 patients with severe asthma based on airway mucosal expression of (1) CCL26 (the most differentially expressed gene), (2) periostin, or (3) a multigene IL-13 in vitro signature (IVS). Clinically accessible biomarkers included fraction of exhaled nitric oxide (Feno) values, blood eosinophil (bEOS) counts, serum CCL26 expression, and serum CCL17 expression. Results Expression of airway mucosal CCL26, periostin, and IL-13–IVS all facilitated segregation of subjects into type 2–high and type 2–low asthmatic groups, but in the ADEPT study population CCL26 expression was optimal. All subjects with high airway mucosal CCL26 expression and moderate-to-severe asthma had Feno values (≥35 ppb) and/or high bEOS counts (≥300 cells/mm 3 ) compared with a minority (36%) of subjects with low airway mucosal CCL26 expression. A combination of Feno values, bEOS counts, and serum CCL17 and CCL26 expression had 100% positive predictive value and 87% negative predictive value for airway mucosal CCL26–high status. Clinical variables did not differ between subjects with type 2–high and type 2–low status. Eosinophilic inflammation was associated with but not limited to airway mucosal type 2 gene expression. Conclusion A panel of clinical biomarkers accurately classified type 2 status based on airway mucosal CCL26, periostin, or IL-13–IVS gene expression. Use of Feno values, bEOS counts, and serum marker levels (eg, CCL26 and CCL17) in combination might allow patient selection for novel type 2 therapeutics.

The endocannabinoids 2-arachidonoyl-glycerol and N-arachidonoyl-ethanolamine mediate an array of pro- and anti-inflammatory effects. These effects are related, in part, to their metabolism by eicosanoid biosynthetic enzymes. For example, N-arachidonoyl-ethanolamine and 2-arachidonoyl-glycerol can be metabolized by cyclooxygenase-2 into PG-ethanolamide (PG-EA) and PG-glycerol (PG-G), respectively. Although PGE2 is a recognized suppressor of neutrophil functions, the impact of cyclooxygenase-derived endocannabinoids such as PGE2-EA or PGE2-G on neutrophils is unknown. This study’s aim was to define the effects of these mediators on neutrophil functions and the underlying cellular mechanisms involved. We show that PGE2-G, but not PGE2-EA, inhibits leukotriene B4 biosynthesis, superoxide production, migration, and antimicrobial peptide release. The effects of PGE2-G were prevented by EP1/EP2 receptor antagonist AH-6809 but not the EP4 antagonist ONO-AE2-227. The effects of PGE2-G required its hydrolysis into PGE2, were not observed with the non-hydrolyzable PGE2-serinol amide, and were completely prevented by methyl-arachidonoyl-fluorophosphate and palmostatin B, and partially prevented by JZL184 and WWL113. Although we could detect six of the documented PG-G hydrolases in neutrophils by quantitative PCR, only ABHD12 and ABHD16A were detected by immunoblot. Our pharmacological data, combined with our protein expression data, did not allow us to pinpoint one PGE2-G lipase, and rather support the involvement of an uncharacterized lipase and/or of multiple hydrolases. In conclusion, we show that PGE2-G inhibits human neutrophil functions through its hydrolysis into PGE2, and by activating the EP2 receptor. This also indicates that neutrophils could regulate inflammation by altering the balance between PG-G and PG levels in vivo.

The endocannabinoid (eCB) 2-arachidonoyl-gycerol (2-AG) modulates immune responses by activating cannabinoid receptors or through its multiple metabolites, notably eicosanoids. Thus, 2-AG hydrolysis inhibition might represent an interesting anti-inflammatory strategy that would simultaneously increase the levels of 2-AG and decrease those of eicosanoids. Accordingly, 2-AG hydrolysis inhibition increased 2-AG half-life in neutrophils. Under such setting, neutrophils, eosinophils, and monocytes synthesized large amounts of 2-AG and other monoacylglycerols (MAGs) in response to arachidonic acid (AA) and other unsaturated fatty acids (UFAs). Arachidonic acid and UFAs were ~1000-fold more potent than G protein-coupled receptor (GPCR) agonists. Triascin C and thimerosal, which, respectively, inhibit fatty acyl-CoA synthases and acyl-CoA transferases, prevented the UFA-induced MAG biosynthesis, implying glycerolipid remodeling. 2-AG and other MAG biosynthesis was preceded by that of the corresponding lysophosphatidic acid (LPA). However, we could not directly implicate LPA dephosphorylation in MAG biosynthesis. While GPCR agonists poorly induced 2-AG biosynthesis, they inhibited that induced by AA by 25%-50%, suggesting that 2-AG biosynthesis is decreased when leukocytes are surrounded by a pro-inflammatory entourage. Our data strongly indicate that human leukocytes use AA and UFAs to biosynthesize biologically significant concentrations of 2-AG and other MAGs and that hijacking the immune system with 2-AG hydrolysis inhibitors might diminish inflammation in humans.

Background: Bronchial Thermoplasty (BT) reduces exacerbations and improves asthma quality of life questionnaire (AQLQ) scores in asthma [1]. Studies have shown reductions in airway smooth muscle (ASM) mass and reticular basement membrane (RBM) thickness after BT, but are limited by small sample size. Aims: To investigate airway remodeling responses to BT, and compare these to clinical outcomes. Methods: Pre- and post-BT data was pooled for 99 patients at 7 centres. ASM mass and RBM thickness were measured on bronchial biopsies, and compared to clinical outcomes. Results: Mean (SD) age was 48.4 years (11.7) and BMI was 29.0 kg/m2 (6.4). Baseline FEV1 was 68.8% predicted (23.1) and blood eosinophils were 0.25x10-9/L (0.26). 59 of 99 patients were taking maintenance oral Prednisolone (mean dose 25.7mg). In response to BT, mean (SD) annual exacerbation rate decreased from 6.4 (5.5) to 1.1 (1.7) (p= Conclusion: ASM mass and RBM thickness reduce rapidly following BT, and effects persist beyond 1 year. The observed improvements in airway remodeling parameters are not related to improvements in clinical outcomes. Other bronchial mucosal changes or mechanisms may play a role in the clinical response to BT. Reference: 1) Castro et al, AJRCCM. 2010;181(2):116-24

Background: BT is an endoscopic treatment for uncontrolled asthma. The long-term efficacy and safety of BT beyond 5 years is not known. Objective: To evaluate the efficacy and safety of BT at 10+ years follow-up. Methods: BT10+ is an international, multi-center, ≥10yrs follow-up study on subjects who were previously enrolled in the AIR, RISA and AIR2 trials. Demographics, quality of life, lung function, severe exacerbations (SE, defined as exacerbations requiring systemic corticosteroids) and healthcare utilisation for the previous year were collected. Results: Of the 429 subjects enrolled in the previous studies, 192 subjects had a follow-up at 10.6-15.8 years (12.1 median) post-treatment at 16 centers: 137 treated with BT during a previous study, 18 control/sham treated with BT post-study, and 37 control/sham only. Rates for hospitalisations, emergency visits and SE for BT subjects from the year prior to BT to the year prior to the BT 10+ visit are shown in Figure 1. No increases in hospitalisations or ER visits were observed compared to baseline and SE were stable compared to Year 1. No deterioration in rates were shown for control/sham only and post-study BT patients. Quality of life and spirometry results were comparable between Years 1, 5, and 10+ for all groups. Conclusion: The BT10+ study suggests that efficacy of bronchial thermoplasty is sustained over 10 years. Funding: Boston Scientific