Sputum macrophage diversity and activation in asthma: role of severity and inflammatory phenotype

BACKGROUND:Macrophages control innate and acquired immunity, but their role in severe asthma remains ill-defined. We investigated gene signatures of macrophage subtypes in the sputum of 104 asthmatics and 16 healthy volunteers from the U-BIOPRED cohort. METHODS:Forty-nine gene signatures (modules) for differentially stimulated macrophages, one to assess lung tissue-resident cells (TR-Mφ) and two for their polarization (classically and alternatively activated macrophages: M1 and M2, respectively) were studied using gene set variation analysis. We calculated enrichment scores (ES) across severity and previously identified asthma transcriptome-associated clusters (TACs). RESULTS:Macrophage numbers were significantly decreased in severe asthma compared to mild-moderate asthma and healthy volunteers. The ES for most modules were also significantly reduced in severe asthma except for 3 associated with inflammatory responses driven by TNF and Toll-like receptors via NF-κB, eicosanoid biosynthesis via the lipoxygenase pathway and IL-2 biosynthesis (all P < .01). Sputum macrophage number and the ES for most macrophage signatures were higher in the TAC3 group compared to TAC1 and TAC2 asthmatics. However, a high enrichment was found in TAC1 for 3 modules showing inflammatory pathways linked to Toll-like and TNF receptor activation and arachidonic acid metabolism (P < .001) and in TAC2 for the inflammasome and interferon signalling pathways (P < .001). Data were validated in the ADEPT cohort. Module analysis provides additional information compared to conventional M1 and M2 classification. TR-Mφ were enriched in TAC3 and associated with mitochondrial function. CONCLUSIONS:Macrophage activation is attenuated in severe granulocytic asthma highlighting defective innate immunity except for specific subsets characterized by distinct inflammatory pathways

Beliefs and preferences regarding biological treatments for severe asthma

Background: Severe asthma is a serious condition with a significant burden on patients' morbidity, mortality, and quality of life. Some biological therapies targeting the IgE and interleukin-5 (IL5) mediated pathways are now available. Due to the lack of direct comparison studies, the choice of which medication to use varies. We aimed to explore the beliefs and practices in the use of biological therapies in severe asthma, hypothesizing that differences will occur depending on the prescribers’ specialty and experience. Methods: We conducted an online survey composed of 35 questions in English. The survey was circulated via the INterasma Scientific Network (INESNET) platform as well as through social media. Responses from allergists and pulmonologists, both those with experience of prescribing omalizumab with (OMA/IL5) and without (OMA) experience with anti-IL5 drugs, were compared. Results: Two hundred eighty-five (285) valid questionnaires from 37 countries were analyzed. Seventy-on percent (71%) of respondents prescribed biologics instead of oral glucocorticoids and believed that their side effects are inferior to those of Prednisone 5 mg daily. Agreement with ATS/ERS guidelines for identifying severe asthma patients was less than 50%. Specifically, significant differences were found comparing responses between allergists and pulmonologists (Chi-square test, p &lt; 0.05) and between OMA/IL5 and OMA groups (p &lt; 0.05). Conclusions: Uncertainties and inconsistencies regarding the use of biological medications have been shown. The accuracy of prescribers to correctly identify asthma severity, according to guidelines criteria, is quite poor. Although a substantial majority of prescribers believe that biological drugs are safer than low dose long-term treatment with oral steroids, and that they must be used instead of oral steroids, every effort should be made to further increase awareness. Efficacy as disease modifiers, biomarkers for selecting responsive patients, timing for outcomes evaluation, and checks need to be addressed by further research. Practices and beliefs regarding the use of asthma biologics differ between the prescriber's specialty and experience; however, the latter seems more significant in determining beliefs and behavior. Tailored educational measures are needed to ensure research results are better integrated in daily practice

Severe Asthma Standard-of-Care Background Medication Reduction With Benralizumab: ANDHI in Practice Substudy

Background: The phase IIIb, randomized, parallel-group, placebo-controlled ANDHI double-blind (DB) study extended understanding of the efficacy of benralizumab for patients with severe eosinophilic asthma. Patients from ANDHI DB could join the 56-week ANDHI in Practice (IP) single-arm, open-label extension substudy. Objective: Assess potential for standard-of-care background medication reductions while maintaining asthma control with benralizumab. Methods: Following ANDHI DB completion, eligible adults were enrolled in ANDHI IP. After an 8-week run-in with benralizumab, there were 5 visits to potentially reduce background asthma medications for patients achieving and maintaining protocol-defined asthma control with benralizumab. Main outcome measures for non-oral corticosteroid (OCS)-dependent patients were the proportions with at least 1 background medication reduction (ie, lower inhaled corticosteroid dose, background medication discontinuation) and the number of adapted Global Initiative for Asthma (GINA) step reductions at end of treatment (EOT). Main outcomes for OCS-dependent patients were reductions in daily OCS dosage and proportion achieving OCS dosage of 5 mg or lower at EOT. Results: For non-OCS-dependent patients, 53.3% (n = 208 of 390) achieved at least 1 background medication reduction, increasing to 72.6% (n = 130 of 179) for patients who maintained protocol-defined asthma control at EOT. A total of 41.9% (n = 163 of 389) achieved at least 1 adapted GINA step reduction, increasing to 61.8% (n = 110 of 178) for patients with protocol-defined EOT asthma control. At ANDHI IP baseline, OCS dosages were 5 mg or lower for 40.4% (n = 40 of 99) of OCS-dependent patients. Of OCS-dependent patients, 50.5% (n = 50 of 99) eliminated OCS and 74.7% (n = 74 of 99) achieved dosages of 5 mg or lower at EOT. Conclusions: These findings demonstrate benralizumab's ability to improve asthma control, thereby allowing background medication reduction

Urinary metabotype of severe asthma evidences decreased carnitine metabolism independent of oral corticosteroid treatment in the U-BIOPRED study

Introduction Asthma is a heterogeneous disease with poorly defined phenotypes. Patients with severe asthma often receive multiple treatments including oral corticosteroids (OCS). Treatment may modify the observed metabotype, rendering it challenging to investigate underlying disease mechanisms. Here, we aimed to identify dysregulated metabolic processes in relation to asthma severity and medication. Methods Baseline urine was collected prospectively from healthy participants (n=100), patients with mild-to-moderate asthma (n=87) and patients with severe asthma (n=418) in the cross-sectional U-BIOPRED cohort; 12–18-month longitudinal samples were collected from patients with severe asthma (n=305). Metabolomics data were acquired using high-resolution mass spectrometry and analysed using univariate and multivariate methods. Results A total of 90 metabolites were identified, with 40 significantly altered (p<0.05, false discovery rate <0.05) in severe asthma and 23 by OCS use. Multivariate modelling showed that observed metabotypes in healthy participants and patients with mild-to-moderate asthma differed significantly from those in patients with severe asthma (p=2.6×10−20), OCS-treated asthmatic patients differed significantly from non-treated patients (p=9.5×10−4), and longitudinal metabotypes demonstrated temporal stability. Carnitine levels evidenced the strongest OCS-independent decrease in severe asthma. Reduced carnitine levels were associated with mitochondrial dysfunction via decreases in pathway enrichment scores of fatty acid metabolism and reduced expression of the carnitine transporter SLC22A5 in sputum and bronchial brushings. Conclusions This is the first large-scale study to delineate disease- and OCS-associated metabolic differences in asthma. The widespread associations with different therapies upon the observed metabotypes demonstrate the need to evaluate potential modulating effects on a treatment- and metabolite-specific basis. Altered carnitine metabolism is a potentially actionable therapeutic target that is independent of OCS treatment, highlighting the role of mitochondrial dysfunction in severe asthma

Impact of comorbid conditions on asthmatic adults and children

Comorbid conditions (comorbidities) can complicate the diagnosis and management of asthma. In different age groups, comorbid conditions can present varying challenges, including diagnostic confusion due to mimicking asthma symptoms, exacerbation of asthma symptoms, therapy for comorbid conditions affecting asthma or therapy for asthma affecting these conditions. This review aims to summarise some common comorbid conditions with asthma, such as rhinitis, vocal cord dysfunction, gastro-oesophageal reflux, psychiatric disorders, obesity and obstructive sleep apnoea, and discuss their prevalence, symptoms, diagnosis and treatment, highlighting any differences in how they impact children and adults. Overall, there is a lack of data on the impact of treating comorbid conditions on asthma outcomes and further studies are needed to guide age-appropriate asthma management in the presence of these conditions.This article is freely available via Open Access. Click on the Publisher URL to access it via the publisher's site.A.K. reports personal fees from AstraZeneca, Behring, Boehringer Ingelheim, GlaxoSmithKline, Griffols, Teva, Novartis, Novo Nordisk, Paladdin, Pfizer, Purdue, Sanofi and Trudel, outside the submitted work. D.M.G.H. reports personal fees from AstraZeneca, Chiesi and Pfizer and grants and personal fees from Boehringer Ingelheim, GlaxoSmithKline and Novartis, outside the submitted work. S.J.S. reports fees from AstraZeneca, Boehringer Ingelheim, GlaxoSmithKline, Novartis, Propeller Health, Regeneron and Sanofi, outside the submitted work all paid to the University of Colorado School of Medicinepublished version, accepted version, submitted versio

Severe Asthma Standard-of-Care Background Medication Reduction With Benralizumab: ANDHI in Practice Substudy

peer reviewedBackground: The phase IIIb, randomized, parallel-group, placebo-controlled ANDHI double-blind (DB) study extended understanding of the efficacy of benralizumab for patients with severe eosinophilic asthma. Patients from ANDHI DB could join the 56-week ANDHI in Practice (IP) single-arm, open-label extension substudy. Objective: Assess potential for standard-of-care background medication reductions while maintaining asthma control with benralizumab. Methods: Following ANDHI DB completion, eligible adults were enrolled in ANDHI IP. After an 8-week run-in with benralizumab, there were 5 visits to potentially reduce background asthma medications for patients achieving and maintaining protocol-defined asthma control with benralizumab. Main outcome measures for non–oral corticosteroid (OCS)-dependent patients were the proportions with at least 1 background medication reduction (ie, lower inhaled corticosteroid dose, background medication discontinuation) and the number of adapted Global Initiative for Asthma (GINA) step reductions at end of treatment (EOT). Main outcomes for OCS-dependent patients were reductions in daily OCS dosage and proportion achieving OCS dosage of 5 mg or lower at EOT. Results: For non–OCS-dependent patients, 53.3% (n = 208 of 390) achieved at least 1 background medication reduction, increasing to 72.6% (n = 130 of 179) for patients who maintained protocol-defined asthma control at EOT. A total of 41.9% (n = 163 of 389) achieved at least 1 adapted GINA step reduction, increasing to 61.8% (n = 110 of 178) for patients with protocol-defined EOT asthma control. At ANDHI IP baseline, OCS dosages were 5 mg or lower for 40.4% (n = 40 of 99) of OCS-dependent patients. Of OCS-dependent patients, 50.5% (n = 50 of 99) eliminated OCS and 74.7% (n = 74 of 99) achieved dosages of 5 mg or lower at EOT. Conclusions: These findings demonstrate benralizumab's ability to improve asthma control, thereby allowing background medication reduction. © 202

Functional analysis of the Hit1p and Bcd1p proteins involved in eukaryotic box C/D snoRNP biogenesis

Chez les eucaryotes, la biogenèse des ribosomes débute dans le nucléole par la maturation et la modification des ARN ribosomiques (ARNr), et fait intervenir des centaines de particules ribonucléoprotéiques (RNP) distinctes, comme les petites RNP nucléolaires (snoRNP) à boîtes C/D, qui portent une activité méthyl transférase ciblée sur la position 2’-OH des riboses. Leur biogenèse nécessite l’intervention transitoire de facteurs protéiques constituant une machinerie d’assemblage spécifique. Mon travail de thèse a visé à étudier le rôle fonctionnel de deux de ces facteurs chez la levure S. cerevisiae les protéines Hit1 et Bcd1. Hit1p avait été trouvée au laboratoire être impliquée dans la biogenèse des snoRNP à boîtes C/D, et il était connu que l’expression de Bcd1p est essentielle à la viabilité cellulaire et pour la stabilité des snoRNA à boîtes C/D. Lors de ce travail, nous avons retrouvé le domaine fonctionnel de Hit1p et identifié les acides aminés impliqués dans l’interaction avec Rsa1p, un autre facteur d’assemblage. Par une approche similaire, nous avons recherché les domaines nécessaires à la fonctionnalité de Bcd1p. Le mécanisme par lequel Bcd1p influence spécifiquement les taux de snoRNA à boîtes C/D reste inconnu, mais au cours de ce travail j’ai identifié un nouveau partenaire potentiel pour cette protéine - la chaperonne d’histone Rtt106p. La dernière partie de mon travail a visé à rechercher le lien fonctionnel entre Rtt106p et l’expression des snoRNA à boîtes C/DIn eukaryotes, ribosome biogenesis begins in the nucleolus, by maturation and modification of ribosomal RNAs (rRNA) and involves hundreds of distinct ribonucleoprotein particles, like box C/D small nucleolar RNPs (snoRNPs). Their assembly requires the transient intervention of protein factors constituting a specific assembly machinery. My PhD work aimed to investigate the functional role of two such factors, Bcd1p and Hit1p, in the yeast S. cerevisiae. Hit1p involvement in box C/D snoRNP biogenesis was revealed in our lab, and it was known that Bcd1p expression is essential to cell viability and box C/D snoRNA stability. During this work, we identified the functional domain of Hit1p, and the aminoacids involved in its interaction with Rsa1, another assembly factor. By a similar approach we identified the functional domains of Bcd1p. The mechanism by which Bcd1p specifically influences box C/D snoRNA levels is unknown. However, I identified a potentially new partner for this protein – the Rtt106p histone chaperone. The last part of my work aimed to search for a functional link between this histone chaperone and box C/D snoRNA expressio

Analyse fonctionnelle des protéines Hit1 et Bcd1 impliquées dans la biogenèse des snoRNP à boîtes C/D eucaryotes

In eukaryotes, ribosome biogenesis begins in the nucleolus, by maturation and modification of ribosomal RNAs (rRNA) and involves hundreds of distinct ribonucleoprotein particles, like box C/D small nucleolar RNPs (snoRNPs). Their assembly requires the transient intervention of protein factors constituting a specific assembly machinery. My PhD work aimed to investigate the functional role of two such factors, Bcd1p and Hit1p, in the yeast S. cerevisiae. Hit1p involvement in box C/D snoRNP biogenesis was revealed in our lab, and it was known that Bcd1p expression is essential to cell viability and box C/D snoRNA stability. During this work, we identified the functional domain of Hit1p, and the aminoacids involved in its interaction with Rsa1, another assembly factor. By a similar approach we identified the functional domains of Bcd1p. The mechanism by which Bcd1p specifically influences box C/D snoRNA levels is unknown. However, I identified a potentially new partner for this protein – the Rtt106p histone chaperone. The last part of my work aimed to search for a functional link between this histone chaperone and box C/D snoRNA expressionChez les eucaryotes, la biogenèse des ribosomes débute dans le nucléole par la maturation et la modification des ARN ribosomiques (ARNr), et fait intervenir des centaines de particules ribonucléoprotéiques (RNP) distinctes, comme les petites RNP nucléolaires (snoRNP) à boîtes C/D, qui portent une activité méthyl transférase ciblée sur la position 2’-OH des riboses. Leur biogenèse nécessite l’intervention transitoire de facteurs protéiques constituant une machinerie d’assemblage spécifique. Mon travail de thèse a visé à étudier le rôle fonctionnel de deux de ces facteurs chez la levure S. cerevisiae les protéines Hit1 et Bcd1. Hit1p avait été trouvée au laboratoire être impliquée dans la biogenèse des snoRNP à boîtes C/D, et il était connu que l’expression de Bcd1p est essentielle à la viabilité cellulaire et pour la stabilité des snoRNA à boîtes C/D. Lors de ce travail, nous avons retrouvé le domaine fonctionnel de Hit1p et identifié les acides aminés impliqués dans l’interaction avec Rsa1p, un autre facteur d’assemblage. Par une approche similaire, nous avons recherché les domaines nécessaires à la fonctionnalité de Bcd1p. Le mécanisme par lequel Bcd1p influence spécifiquement les taux de snoRNA à boîtes C/D reste inconnu, mais au cours de ce travail j’ai identifié un nouveau partenaire potentiel pour cette protéine - la chaperonne d’histone Rtt106p. La dernière partie de mon travail a visé à rechercher le lien fonctionnel entre Rtt106p et l’expression des snoRNA à boîtes C/

AVANCEES DANS LA COMPREHENSION DE L’ASTHME: DE LA CLINIQUE A LA PHYSIOPATHOLOGIE ET LA BIOLOGIE MOLECULAIRE

Asthma is one of the most frequent obstructive airway diseases with a prevalence of 6-12% in the adult population across the world. It is a heterogeneous disease characterized by chronic airway inflammation associated with bronchial hyperresponsiveness and symptoms such as wheezing, dyspnoea, cough, and chest tightness. Despite a controller treatment according to the current guidelines (e.g. inhaled/systemic corticosteroids, leukotriene receptor antagonists), 17% of adult asthmatics have difficult-to-treat asthma with a negative impact on their quality of life and high costs for the healthcare system. These patients should be addressed in expert centers in order to optimize their management. However, despite the optimization, 4% of asthmatic patients finally have the diagnosis of severe asthma. Most of the recent research was focused on the identification of different phenotypes of severe asthma and the mechanisms driving the inflammatory reaction for each phenotype in order to find biomarkers and to better adapt the therapeutic strategy to every patient. Several phenotypes were described but not all of the mechanisms involved are identified. The present work summarises my contribution to the understanding of mechanisms driving different phenotypes of severe asthma and my future projects in order to improve the management of asthmatic patients (particularly those with severe asthma) and the applying of personalized medicine in this domain