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BackgroundIdiopathic pulmonary fibrosis (IPF) is a rare lung disease of unknown origin leading rapidly to death. This paper addresses the issue of whether sputum induction is a suitable tool to study respiratory tract inflammation and potential biomarkers in IPF compared to COPD, a fibrosing airway wall disease.MethodsIn a cross-sectional analysis, 15 IPF patients, 32 COPD and 30 healthy subjects underwent sputum induction. Total sputum cell counts and the amount of TGF- β, IGF-1, IGF-2, IGFBP-1, IGFBP-2, IGFBP-3, IL-8, IL-13, MMP-7, MMP-9, YKL-40, TNF-α and KL-6 in sputum supernatant were analysed. We also profiled gene expression of cells in the induced sputum for TGF-β, MMP-7, YKL-40, IGFBP-2, IL-6, IL-8 and TNF-α.ResultsIPF patients, like COPD, had increased sputum absolute number of neutrophils, eosinophils, macrophages and epithelial cells compared to HS. IPF sputum supernatants had increased concentrations of IGFBP-2, IL-8, TGF-β, MMP-7, MMP-9 and KL-6 (pConclusionOur data show clear increase in expression and production of IGFBP-2, IL-8 and MMP-7 in sputum from patients with IPF that may contribute to the disease.

Abstract Background Idiopathic pulmonary fibrosis (IPF) is a progressive, fatal lung disorder of unknown origin with a highly variable and unpredictable clinical course. Polymorphisms and environmentally induced epigenetic variations seem to determine individual susceptibility to the development of lung fibrosis. Methods We have studied circulating epitopes on cell-free nucleosomes (cfnucleosomes) in 50 IPF patients. We have compared untreated IPF (n = 23) with IPF receiving antifibrotic therapy (n = 27) and healthy subjects (HS) (n = 27). We analyzed serum levels of five cfnucleosomes including bound HMGB1 (nucleosomes adducted to high-mobility growth protein B1), mH2A1.1 (nucleosomes containing the histone variant mH2A1.1), 5mC (nucleosomes associated with methylated DNA), and H3K9Ac and H3K27Ac (nucleosomes associated with histone H3 acetylated at lysine 9 or 27 residue). Results Our findings showed that serum levels of bound HMGB1, mH2A1.1, 5mC, H3K9Ac, and H3K27Ac were significantly lower in IPF patients than in HS (p

Abstract Systemic sclerosis (SSc) is a potentially serious and disabling connective tissue disease specially in case of interstitial lung disease (SSc-ILD). The aim of our study was to evaluate the potential utility of dosing in the induced sputum (IS) and to compare their levels in SSc-ILD and SSc-nonILD patients, as well as in healthy volunteers (HV). IS and sera values were also compared. In a prospective cross-sectional analysis, we studied the IS and serum provided from 25 SSc patients, 15 SSc-nonILD and 10 SSc-ILD, compared to 25 HV. We analyzed sputum cell composition and quantified in the supernatant and corresponding serum by commercially available immunoassays: IGFBP-1, IGFBP-2, IGFBP-3, TGF-β, IL-8, TNF-α, YKL-40, MMP-7 and MMP-9. Lung function was studied by the determination of FEV-1 (%), FVC (%), DLCO (%) and KCO (%). The IS of SSc patients had a lower weight than HV (p

Background: There is a pressing need to identify early biomarkers of lung involvement in systemic sclerosis (SSc) to start as soon as possible antifibrotic therapy. We aimed to identify extracellular vesicle-derived microRNAs (EV-miRNAs) that are differentially expressed between SSc patients with and without interstitial lung disease (ILD), explore their diagnostic value and investigate their functional properties., Methods: Small EVs (sEVs) derived from plasma were isolated from 91 well-characterised SSc patients with ILD (SSc-ILD, n=45), without ILD (SSc-no ILD, n=46) and 43 matched healthy subjects (HS). Small RNA sequencing followed by quantitative RT-PCR were used to identify and validate sEV-miRNAs associated to SSc-ILD. Correlations between SSc-ILD-associated miRNAs and clinical parameters were assessed, as well as the impact of related miRNAs/sEVs on fibrosis., Results: We identified a 4-miRNA signature associated with ILD in SSc context (miR-584-5p, miR-744-5p, miR-1307-3p and miR-10b-5p) (ROC AUC=0.85, 95% CI 0.76-0.94, p<0.0001). Deeper analysis revealed a correlation of these candidates with pulmonary function tests (DLCO and FVC), highlighting their capacity to monitor lung fibrosis progression in SSc patients. Furthermore, SSc-ILD-associated sEV miRNAs are positively correlated and enriched in circulating lymphocytes, suggesting that these immune cells are their cellular source. Finally, functional studies highlighted an alteration of functional properties of sEVs in SSc-ILD context mainly due to the transfer of profibrotic miR-584-5p in lung fibroblasts., Conclusions: Our sEV-based biomarker approach enabled to identify a promising 4-miRNA signature characteristic of ILD in SSc patients. Furthermore, the profibrotic properties of SSc-ILD-associated sEVs suggest a prominent role of these vesicles on SSc severity., (Copyright ©The authors 2025.)

Background: Mucociliary clearance (MCC) impairment can be due to mucus abnormalities or to a ciliary dysfunction, which can be innate, or secondary to infection and/or inflammation. In cystic fibrosis (CF), it is well documented that MCC is impaired due to mucus abnormalities, but little is known concerning ciliary beating. This study aimed to confirm that ciliary dyskinesia is present in CF, and if this might be innate or secondary to the chronic infection and/or inflammation., Methods: Ciliated epithelial samples were obtained by nasal brushing from 51 CF patients, and from 30 healthy subjects. Ciliary beating was evaluated using digital high-speed videomicroscopy at 37 °C, allowing to evaluate ciliary beat frequency (CBF) and the percentage of abnormal beat pattern (CBP); this was repeated after air-liquid interface (ALI) cell culture., Results: Ciliary dyskinesia was higher in CF patients than in healthy subjects, with a lower CBF and a higher percentage of abnormal CBP. Ciliary dyskinesia, already present in childhood, normalized after ALI cell culture. A chronic airway colonization did not worsen ciliary dyskinesia., Conclusions: We showed that, in CF, a ciliary dyskinesia, present from childhood, might contribute to the impaired MCC. Our results also found that the abnormal ciliary beating was not associated with a chronic infection, and resolved after ALI cell culture, suggesting that ciliary dyskinesia in CF is not innate, and might be secondary to chronic inflammation., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Anne-Lise Poirrier reports a relationship with GSK that includes: consulting or advisory and speaking and lecture fees. Anne-Lise Poirrier reports a relationship with Sanofi that includes: consulting or advisory and speaking and lecture fees. Renaud Louis reports a relationship with GSK that includes: consulting or advisory, funding grants, and speaking and lecture fees. Renaud Louis reports a relationship with AstraZeneca that includes: consulting or advisory, funding grants, and speaking and lecture fees. Renaud Louis reports a relationship with Chiesi that includes: funding grants and speaking and lecture fees. Florence Schleich reports a relationship with GSK that includes: consulting or advisory, funding grants. Florence Schleich reports a relationship with AstraZeneca that includes: consulting or advisory, funding grants. Florence Schleich reports a relationship with ALK that includes: consulting or advisory. Florence Schleich reports a relationship with Novartis that includes: consulting or advisory. Celine Kempeneers reports a relationship with Sanofi that includes: consulting or advisory., (Copyright © 2024. Published by Elsevier B.V.)

Introduction: Physical inactivity due to shortness of breath is common among patients with uncontrolled asthma. We evaluated the body mass composition and exercise capacity of patients with poorly controlled asthma, despite maximal inhalation therapy., Methods:  We recruited 56 patients from the Asthma Clinic of the University Hospital of Liège between September 2020 and December 2023, and 14 healthy subjects. Patients with asthma underwent detailed investigations, including induced sputum, exercise testing, and Dual-Energy X-ray Absorptiometry (DXA), to determine overall body fat mass and fat-free mass, while healthy subjects only underwent DXA. This study was approved by the Ethics Committee (2019/362)., Results:  The mean age of patients with asthma was 45 years ± 12; 58% were female, 10% were active smokers, and mean post-BD Forced Expiratory Volume in one second was 85.7% predicted. Compared to healthy subjects, asthmatics had a higher BMI (28.5±5.1 kg/m2 vs 22.5 ±2.8 kg/m2, p<0.0001) and fat mass index (FMI; 10.3 ± 3.7 vs 5.9 ± 2.8 kg/m2, p=0.0005), lower lean and bone mass (62% vs 71%, p=0.0012), and greater android fat distribution (1.00 ± 0.22 vs 0.80 ± 0.13, p<0.0001). Eosinophilic asthma (sputum eosinophil count of ≥3%) was characterized by a better VO 2 max compared to non-eosinophilic asthma (20.7 [17.8-24.3] vs 17.3 [14.0-18.9], p=0.04). Higher lean mass was correlated with better asthma control and lower depression scores. Lean mass and bone mineral content correlated with maximal expiratory, inspiratory, and maximal aerobic power., Conclusion:  Our study confirmed that patients with uncontrolled asthma were overweight and had decreased exercise capacity., Competing Interests: Prof. Dr. Florence Schleich reports grants from Gsk, grants from Chiesi, grants from AstraZeneca, outside the submitted work. The authors report no other conflicts of interest in this work., (© 2024 Schleich et al.)

Background: Asthma is associated with accelerated rate of FEV 1 decline., Objective: To determine predictive factors associated with accelerated FEV 1 decline in adult asthma and evaluate sputum cytokines as potential biomarkers for airflow decline., Methods: We recruited 125 asthmatics evaluated at the asthma clinic of Liège and reevaluated them at least 5 years later. Clinical, functional and inflammatory characteristics were compared between patients with accelerated decline (FEV 1 decline > 0.85% pred.y -1 ) and others. Predictive factors were highlighted with linear regression analysis. Sputum EGF, VEGF, FGF, IL5, IL8, TGF-β, and IgE levels were measured in 58 of these patients at both visits by Human XL cytokine Luminex Performance assay and Elisa., Results: Post-BD FEV 1 decline was 0.06 ± 2.44% pred.y -1 in the overall population. Median (IQR) time between visits was 66 (62 - 86) months. The multivariable analysis showed that an increase in blood eosinophils over time (Δ BEC) (Reg. Coef. (95%CI): 0.002 (0.001 to 0.004), p = 0.005)) and onset of asthma (0.04 (0.003 to 0.07), p = 0.036) were independently associated with FEV 1 decline. IL8 levels measured at baseline were higher (499 (408-603) pg/ml, p = 0.0040) in patients with accelerated decline compared to others (143 (88-308) pg/ml)., Conclusion: In this study, we have confirmed that an increase in blood eosinophil counts over a follow-up of at least 5 years and later onset of asthma are associated with accelerated annual FEV 1 decline. Moreover, high sputum IL8 levels could be a risk factor for accelerated decline in asthma patients., Competing Interests: Declarations. Conflict of interests: Graff S, Moermans C, Gerday S, Henket M, Paulus P, and Guissard F have nothing to disclose. Prof. LOUIS reports grants and personal fees from GSK, grants and personal fees from AZ, grants and personal fees from Novartis, grants from Chiesi, outside the submitted work. Prof. Schleich reports grants and personal fees from GSK, grants from AZ, grants and personal fees from Chiesi, outside the submitted work. Ethical Approval: CHU Liège: 2008/181. Informed Consent: Informed consent was obtained from all individual participants included in the study. Consent for Publication: Not applicable., (© 2024. The Author(s).)

Here we present pharmacological and clinical properties of a new biological targeting TSLP (Thymic Stromal LymphoPoietin). Tezspire® is the name of this targeted treatment which contains 210 mg tezepelumab administered subcutaneously once a month. As compared to placebo, tezepelumab reduced exacerbations whatever the baseline blood eosinophil counts, exhaled nitric oxide (FeNO) level and atopic status. The response was higher in patients exhibiting the highest levels of blood eosinophils and FeNO. Tezepelumab also improved pre- bronchodilatation forced expiratory volume in one second, symptomatic control of asthma and quality of life. Tezepelumab proved a broad anti-inflammatory effect by blocking IL-4, IL-13 and IL-5 pathways, inducing a significant reduction in serum total IgE levels, FeNO, blood and sub-mucosal eosinophils, without affecting neutrophil level. Tezepelumab also reduced bronchial hyperresponsiveness and mucus plugs.

Background: Randomised controlled trials have shown that benralizumab, an anti-interleukin-5 receptor monoclonal antibody, reduces exacerbations and oral corticosteroid dose and improves asthma control and lung function in severe eosinophilic asthma. The aim of this study was to confirm results of randomised controlled trials in real life in a population of 73 patients with severe eosinophilic asthma treated with benralizumab for at least 12 months., Methods: Patients underwent careful monitoring of asthma exacerbations, exhaled nitric oxide fraction, lung function, asthma control and quality of life questionnaire responses and sputum induction, and gave a blood sample at baseline, after 6 months and then every year., Results: We found significant reductions in exacerbations (by 92%, p<0.0001) and oral corticosteroid dose (by 83%, p<0.001) after 6 months that were maintained over time, with 78% of patients able to stop oral corticosteroid therapy. Patients improved their Asthma Control Test (ACT) score (from 11.7±5.1 to 16.9±5.35, p<0.0001), Asthma Control Questionnaire (ACQ) score (from 2.88±1.26 to 1.77±1.32, p<0.0001) and Asthma Quality of Life Questionnaire score (+1.04, p<0.0001) at 6 months and this was maintained during follow-up. Only 35% and 43% of patients reached asthma control according to an ACT score ≥20 and ACQ score <1.5, respectively. We observed stable post-bronchodilation lung function over time and a significant reduction in sputum eosinophil count, with 85% of patients exhibiting sputum eosinophil counts <3% after 6 months (p<0.01) with no effect on exhaled nitric oxide fraction., Conclusion: In our real-life study, we confirm the results published in randomised controlled trials showing a sharp reduction in exacerbations and oral corticosteroid therapy, an improvement in asthma control and quality of life, and a dramatic reduction in sputum eosinophil count., Competing Interests: Conflict of interest: F. Schleich reports grants or contracts from GSK, AstraZeneca, Chiesi and Novartis, outside the submitted work; consulting fees from GSK, AstraZeneca, Chiesi and Novartis, outside the submitted work; and lectures for GSK, AstraZeneca, Chiesi and Novartis, outside the submitted work. Conflict of interest: A-L. Poirrier reports a speaker honorarium from GlaxoSmithKline Pharmaceuticals SA outside the submitted work; and advisory board honoraria from GlaxoSmithKline Pharmaceuticals SA and Sanofi Aventis Belgium SA, outside the submitted work. Conflict of interest: R. Louis reports grants or contracts from GSK, AstraZeneca and Chiesi, outside the submitted work; payment or honoraria for lectures, presentations, speakers’ bureaus, manuscript writing or educational events from GSK, AstraZeneca, Chiesi and TEVA, outside the submitted work; and participation on a data safety monitoring or advisory board for GSK and AstraZeneca, outside the submitted work. Conflict of interest: The remaining authors have nothing to disclose., (Copyright ©The authors 2023.)

Several clinical trials have demonstrated that anti-IL-5(R) biologics were able to improve lung function, asthma control and chronic oral corticosteroid exposure and reduce exacerbations among eosinophilic asthmatic patients. However, a certain variability in clinical responses to anti-IL-5(R) biologics was brought to light. Our study aimed at evaluating the role of baseline sputum eosinophils in identifying super-responders to mepolizumab and benralizumab. Our study reinforces the importance to examine sputum eosinophils in patients suffering from severe asthma before starting a biologic as it is associated with the intensity of response to mepolizumab and benralizumab., Competing Interests: Competing interests: GERDAY Sara, GRAFF Sophie, MOERMANS Catherine, GUISSARD Françoise, PAULUS Virginie and HENKET Monique declare no competing interests. LOUIS Renaud reports grants from GSK, Astrazeneca, Chiesi; royalties from patent AU2016328384, CA2997506, EP 3337393, US2020345266; consulting fees from Astrazeneca; lecture payments from GSK, Chiesi; participation on a data safety monitoring board or advisory board for Astrazeneca ANDHI in practice study and leadership or fiduciary role in other board, society, committee or advocacy group for ERS task force on guidelines on asthma diagnosis, outside the submitted work. SCHLEICH Florence reports grants from GSK, Astrazeneca, Chiesi; consulting fees from GSK, Astrazeneca, Sanofi; lecture payments from GSK, Astrazeneca, Teva, Chiesi and Amgen and support for attending meetings/travel from Chiesi, outside the submitted work., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Chronic mucus hypersecretion (CMH) is linked to increased asthma severity. Ciliary dyskinesia is present in severe asthma but CMH was not associated with a worse ciliary dysfunction, suggesting another mechanism to explain chronic cough and phlegm. https://bit.ly/3JNUgGr., Competing Interests: Conflict of interest: C. Kempeneers has received consulting fees from Sanofi (international advisory board). R. Louis and F. Schleich have received educational and research grants from GSK, AstraZeneca and Chiesi; consulting fees from GSK and AstraZeneca (national and international advisory boards); and lecture fees from GSK, AstraZeneca and Chiesi. F. Schleich has received lecture fees from TEVA. R. Bonhiver, N. Bricmont, M. Pirotte, S. Engelskirchen, L. Benchimol, D. Calmes, F. Guissard, C. Moermans and M-C. Seghaye have no conflicts to declare., (Copyright ©The authors 2023.)

Background: Staphylococcus aureus enterotoxins (SE) may act as superantigens and induce an intense T-cell activation, causing local production of polyclonal IgE and resultant eosinophil activation., Objective: To assess whether asthma with sensitization to SE but not to common aeroallergens (AAs) displays different inflammatory characteristics., Methods: We conducted a prospective study on a series of 110 consecutive patients with asthma recruited from the University Asthma Clinic of Liège. We compared clinical, functional, and inflammatory characteristics of this general population of patients with asthma categorized into 4 groups according to sensitization to AAs and/or SE. We also compared sputum supernatant cytokines in patients sensitized to SE or not., Results: Patients with asthma sensitized only to AAs represented 30%, while 29% were sensitized to both AAs and SE. One-fifth of the population had no specific IgE. Sensitization to SE but not to AA (21%) was associated with later onset of disease, higher rate of exacerbations, nasal polyps, and more severe airway obstruction. As for airway type 2 biomarkers, patients presenting with specific IgE against SE displayed higher fractional exhaled nitric oxide, sputum IgE, and sputum IL-5 levels but not IL-4. We confirm that the presence of specific IgE against SE is associated with elevated serum IgE to levels well above those observed in patients sensitized only to AAs., Conclusions: Our study suggests that asthma specialists should measure specific IgE against SE during the phenotyping process because it may allow the identification of a subgroup of patients with more asthma exacerbations, more nasal polyposis and chronic sinusitis, lower lung function, and more intense type 2 inflammation., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Primary ciliary dyskinesia is a heterogeneous, inherited motile ciliopathy in which respiratory cilia beat abnormally, and some ultrastructural ciliary defects and specific genetic mutations have been associated with particular ciliary beating alterations. Ciliary beating can be evaluated using digital high-speed videomicroscopy (DHSV). However, normal reference values, essential to assess ciliary beating in patients referred for a PCD diagnostic, vary between centres, as minor variations in protocols might influence ciliary beating. Consequently, establishment of normal values is essential for each PCD diagnostic centre. We aimed to evaluate whether delay after sampling, and temperature for conservation of respiratory ciliated samples, might modify assessments of ciliary beating. In total, 37 healthy nasal brushing samples of respiratory ciliated epithelia were collected. Video sequences were recorded at 37 °C immediately using DHSV. Then, the samples were divided and conserved at 4 °C or at room temperature (RT). Ciliated beating edges were then recorded at 37 °C, at 3 h and at 9 h post sampling. In six samples, recordings were continued up to 72 h after sampling. Ciliary beating was assessed manually by ciliary beat frequency (CBF M ) and ciliary beat pattern (CBP). A semi-automatic software was used for quantitative analysis. Both CBF and CBP evaluated manually and by a semi-automated method were stable 9 h after sampling. CBF M was higher when evaluated using samples stored at RT than at 4 °C. CBP and the semi-automated evaluation of ciliary beating were not affected by storage temperature. When establishing normal references values, ciliary beating can be evaluated at 37 °C up to 9 h after nasal brushing, but the storage temperature modifies ciliary beating and needs to be controlled.

Background: Biotherapies targeting IL-5 allow a tangible improvement of asthma. However, all patients do not respond the same way to these treatments. Even if high blood eosinophil counts seem to be associated with a reduction in exacerbations with treatment targeting IL-5, we lack biomarkers for the prediction of remission after these very expensive treatments., Research Question: Are there biomarkers of remission after therapy targeting IL-5 in the sputum of patients with severe eosinophilic asthma?, Study Design and Methods: This observational study included 52 patients with severe asthma initiated with anti-IL-5 therapy and recruited from the asthma clinic of the Centre Hospitalier Universitaire of Liege, Belgium. Remission was defined as patients who combined the following at 1 year after therapy: no chronic treatment with oral corticosteroids; no exacerbation; asthma control questionnaire score < 1.5, asthma control test score > 19, or both; FEV 1 of ≥ 80% predicted, improvement of FEV 1 of ≥ 10%, or both; and a blood eosinophil count < 300 cells/μL. Eosinophil peroxidase (EPX), IgE, IL-3, IL-4, IL-5, IL-13, IL-25, IL-33, granulocyte-macrophage colony-stimulating factor, thymic stromal lymphopoietin (TSLP), and eotaxin-1 levels were measured in the sputum of these patients before anti-IL-5 treatment., Results: Among the 52 patients, 11 were classified as being in remission. These patients were characterized by higher sputum eosinophil, macrophage, and lymphocyte counts, whereas the sputum neutrophil percentage was lower than in the nonremission group. In addition, the sputum eotaxin-1, TSLP, IL-5, EPX, and IgE protein levels were higher at baseline in the remission group compared with the nonremission group. Univariate regression analysis revealed that male vs female sex, sputum neutrophil percentage, eotaxin-1, IL-5, and EPX were potential predictors of remission., Interpretation: Sputum type 2 markers seemed to be potentially predictive of remission after anti-IL-5 therapy in a cohort of patients with severe eosinophilic asthma. These results need validation on a larger cohort., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Asthma affects over 300 million people worldwide and its prevalence is increasing. COPD is the third leading cause of death globally. Asthma and COPD are complex inflammatory diseases of the airways in which impaired host defences lead to increased susceptibility to pathogens, pollutants and allergens. There is a constant interplay between host and the environment. Environmental exposures can alter the lung microbiome and influence the development of sensitisation by disrupting normal immunoregulation. The underlying airway inflammation in severe asthma is heterogeneous, with upregulation of type 2 cytokines in most cases but increased neutrophilic inflammation and activated T-helper 17 mediated immunity in others. COPD may also comprise several different phentoypes that are driven by different molecular mechanisms or endotypes. This disease heterogeneity is affected by comorbidities, treatments and environmental exposures. Recent intervention trials have shed light on the pathways beyond type 2 inflammation that can lead to beneficial outcomes versus potentially deleterious effects. We have made a great deal of progress over the last 10 years in terms of immunology and the pathophysiology of asthma and this has led to the development of novel treatments and major improvements in severe asthma outcomes. In COPD, however, no targeted treatments have demonstrated great improvements. This article reviews the mechanism of action and efficacy of the available biologics in asthma and COPD., Competing Interests: Conflict of interest: F. Schleich has received grants or contracts from GSK, AstraZeneca and Chiesi; payment or honoraria for lectures, presentations, speakers’ bureaus, manuscript writing or educational events from GSK, AstraZeneca, Chiesi and TEVA; and has participated on a Data Safety Monitoring Board or Advisory Board for GSK and AstraZeneca. Conflict of interest: N. Bougard has nothing to disclose. Conflict of interest: C. Moermans has nothing to disclose. Conflict of interest: M. Sabbe has nothing to disclose. Conflict of interest: R. Louis has received grants or contracts from GSK, AstraZeneca and Chiesi; payment or honoraria for lectures, presentations, speakers’ bureaus, manuscript writing or educational events from GSK, AstraZeneca, Chiesi and TEVA; and has participated on a Data Safety Monitoring Board or Advisory Board for GSK and AstraZeneca., (Copyright ©The authors 2023.)

Background: Pulmonary fibrosis is an emerging complication of SARS-CoV-2 infection. In this study, we speculate that patients with COVID-19 and idiopathic pulmonary fibrosis (IPF) may share aberrant expressed microRNAs (miRNAs) associated to the progression of lung fibrosis., Objective: To identify miRNAs presenting similar alteration in COVID-19 and IPF, and describe their impact on fibrogenesis., Methods: A systematic review of the literature published between 2010 and January 2022 (PROSPERO, CRD42022341016) was conducted using the key words (COVID-19 OR SARS-CoV-2) AND (microRNA OR miRNA) or (idiopathic pulmonary fibrosis OR IPF) AND (microRNA OR miRNA) in Title/Abstract., Results: Of the 1988 references considered, 70 original articles were appropriate for data extraction: 27 studies focused on miRNAs in COVID-19, and 43 on miRNAs in IPF. 34 miRNAs were overlapping in COVID-19 and IPF, 7 miRNAs presenting an upregulation (miR-19a-3p, miR-200c-3p, miR-21-5p, miR-145-5p, miR-199a-5p, miR-23b and miR-424) and 9 miRNAs a downregulation (miR-17-5p, miR-20a-5p, miR-92a-3p, miR-141-3p, miR-16-5p, miR-142-5p, miR-486-5p, miR-708-3p and miR-150-5p)., Conclusion: Several studies reported elevated levels of profibrotic miRNAs in COVID-19 context. In addition, the balance of antifibrotic miRNAs responsible of the modulation of fibrotic processes is impaired in COVID-19. This evidence suggests that the deregulation of fibrotic-related miRNAs participates in the development of fibrotic lesions in the lung of post-COVID-19 patients., (© 2023. The Author(s).)

Asthma is the most prevalent chronic inflammatory airway disease worldwide. The gut microbiota possesses an important link with the development of the immunity in youth and a dysregulation of the gut flora was implicated in the asthmatic disease emergence. Moreover, a dysregulation of the intestinal microbiota exists in asthmatic individual. Probiotics are micro-organisms that can regulate our microbiome conferring potential beneficial effects on health. Thereby, their use in asthma prevention and treatment is attractive and could lead to new therapeutic perspectives. Indeed, they are well tolerated and safe and possess anti-inflammatory and immunoregulatory properties. This article is intended to update the current state of knowledge regarding the use of probiotics in the context of asthma.

Asthma is a chronic inflammatory disease of the airways. Classification of asthma in different phenotypes has therapeutic implications and may lead to personalized medicine. Induced sputum is the gold standard for asthma phenotyping but is complex, time-consuming and not widely available. The combination of different biomarkers such as exhaled nitric oxide, blood eosinophils and total serum IgE levels allows the prediction of inflammatory phenotype in 58% of asthmatic patients when sputum is not available. We recently demonstrated the interest of measuring volatile organic compounds in exhaled breath to phenotype asthma. These compounds could play an important role in the future to predict the response to expensive biologicals available in severe asthma to reduce exacerbations and the use of systemic corticosteroids.

Chronic Obstructive Pulmonary Disease (COPD) is a disease caused by a chronic inflammatory response induced by the inhalation of cigarette smoke or toxic particles/gases in the airways. However, we actually know that COPD is a disease that does not only induce inflammation in lung parenchyma and bronchi, but also provokes systemic inflammation which plays a role in multiple comorbidities. Thereby, treatment of COPD should not only focus on the bronchi to relieve symptoms, improve respiratory function and reduce the rate of exacerbations, but must also be extended to the systemic effects of the disease.

Background: Patients suffering from combined obstructive and interstitial lung disease (O-ILD) represent a pathological entity which still has to be well clinically described. The aim of this descriptive and explorative study was to describe the phenotype and functional characteristics of a cohort of patients suffering from functional obstruction in a population of ILD patients in order to raise the need of dedicated prospective observational studies and the evaluation of the impact of anti-fibrotic therapies., Methods: The current authors conducted a retrospective study including 557 ILD patients, with either obstructive (O-ILD, n = 82) or non-obstructive (non O-ILD, n = 475) pattern. Patients included were mainly males (54%) with a mean age of 62 years., Results: Patients with O-ILD exhibited a characteristic functional profile with reduced percent predicted forced expired volume in 1 s (FEV1) [65% (53-77) vs 83% (71-96), p < 0.00001], small airway involvement assessed by maximum expiratory flow (MEF) 25/75 [29% (20-41) vs 81% (64-108), p < 0.00001], reduced sGaw [60% (42-75) vs 87% (59-119), p < 0.01] and sub-normal functional residual capacity (FRC) [113% (93-134) vs 92% (75-109), p < 0.00001] with no impaired of carbon monoxide diffusing capacity of the lung (DLCO) compared to those without obstruction. Total lung capacity (TLC) was increased in O-ILD patients [93% (82-107) vs 79% (69-91), p < 0.00001]. Of interest, DLCO sharply dropped in O-ILD patients over a 5-year follow-up. We did not identify a significant increase in mortality in patients with O-ILD. Interestingly, the global mortality was increased in the specific sub-group of patients with O-ILD and no progressive fibrosing ILD phenotype and in those with connective tissue disease associated ILD especially in case of rheumatoid arthritis., Conclusions: The authors individualized a specific functional-based pattern of ILD patients with obstructive lung disease, who are at risk of increased mortality and rapid DLCO decline over time. As classically those patients are excluded from clinical trials, a dedicated prospective study would be of interest in order to define more precisely treatment response of those patients., (© 2022. The Author(s).)

Acute respiratory distress syndrome (ARDS) is a diffuse, acute, inflammatory lung disease characterized by a severe respiratory failure. Recognizing and promptly treating ARDS is critical to combat the high mortality associated with the disease. Despite a significant progress in the treatment of ARDS, our ability to identify early patients and predict outcomes remains limited. The development of novel biomarkers is crucial. In this study, we profiled microRNA (miRNA) expression of plasma-derived exosomes in ARDS disease by small RNA sequencing. Sequencing of 8 ARDS patients and 10 healthy subjects (HSs) allowed to identify 12 differentially expressed exosomal miRNAs (adjusted p < 0.05). Pathway analysis of their predicted targets revealed enrichment in several biological processes in agreement with ARDS pathophysiology, such as inflammation, immune cell activation, and fibrosis. By quantitative RT-PCR, we validated the alteration of nine exosomal miRNAs in an independent cohort of 15 ARDS patients and 20 HSs, among which seven present high capability in discriminating ARDS patients from HSs (area under the curve > 0.8) (miR-130a-3p, miR-221-3p, miR-24-3p, miR-98-3p, Let-7d-3p, miR-1273a, and miR-193a-5p). These findings highlight exosomal miRNA dysregulation in the plasma of ARDS patients which provide promising diagnostic biomarkers and open new perspectives for the development of therapeutics., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Parzibut, Henket, Moermans, Struman, Louis, Malaise, Louis, Misset, Njock and Guiot.)

Systemic sclerosis (SSc) is a rare connective tissue disease associated with rapid evolving interstitial lung disease (ILD), driving its mortality. Specific biomarkers associated with the progression of this lung disease are highly needed. We aimed to identify specific biomarkers of SSc-ILD to predict the evolution of the disease. For this, we compared prospectively serum levels of several biomarkers associated with lung fibrosis in SSc patients (n = 102), among which SSc-no ILD (n = 63) and SSc-ILD (n = 39), compared to healthy subjects (HS) (n = 39). We also performed a longitudinal study in a subgroup of 28 patients analyzing biomarkers variations and pulmonary function tests over a period of 2 years. Serum level of IGFBP-2 was significantly increased in SSc patients compared to HS, and negatively correlated with pulmonary function (assessed by carbon monoxide transfer coefficient (KCO)) (r = - 0.29, p < 0.01). Two-year longitudinal analysis in a subgroup of 28 SSc patients determined that IGFBP-2 variation was positively correlated with KCO at 2-year follow-up (r = 0.6, p < 0.001). SSc patients with a lower variation of IGFBP-2 (less than 22%) presented significant deterioration of pulmonary function at 2-year follow-up (p < 0.01). ROC curve analysis enabled us to identify that baseline IGFBP-2 > 105 ng/ml was associated with a poor outcome (KCO < 70% predicted) at 2-year follow-up (AUC = 0.75, p < 0.05). We showed for the first time that serum levels of IGFBP-2 might be a prognostic factor of the development of SSc-ILD.

Introduction: Alarmins ((IL-25, IL-33 and thymic stromal lymphopoietin (TSLP)) are known to promote Th2 inflammation and could be associated with eosinophilic airway infiltration. They may also play a role in airway remodeling in chronic airway obstructive diseases such as asthma and chronic obstructive pulmonary disease (COPD). IL-23 and IL-36 were shown to mediate the neutrophilic airway inflammation as seen in chronic airway obstructive diseases., Objectives: The purpose of this project was to determine the expression and the production of these cytokines from induced sputum (IS) in patients with chronic airway obstructive diseases including asthmatics and COPD. The relationship of the mediators with sputum inflammatory cellular profile and the severity of airway obstruction was assessed., Methods: The alarmins (IL-25, IL-33 and TSLP) as well as IL-23 and IL-36 concentrations were measured in IS from 24 asthmatics and 20 COPD patients compared to 25 healthy volunteers. The cytokines were assessed by ELISA in the IS supernatant and by RT-qPCR in the IS cells., Results: At protein level, no difference was observed between controls and patients suffering from airway obstructive diseases regarding the different mediators. IL-36 protein level was negatively correlated with sputum eosinophil and appeared significantly decreased in patients with an eosinophilic airway inflammation compared to those with a neutrophilic profile and controls. At gene level, only IL-36, IL-23 and TSLP were measurable but none differed between controls and patients with airway obstructive diseases. IL-36 and IL-23 were significantly increased in patients with an neutrophilic inflammatory profile compared to those with an eosinophilic inflammation and were correlated with sputum neutrophil proportions. None of the mediators were linked to airway obstruction., Conclusions: The main finding of our study is that patients with eosinophilic airway inflammation exhibited a reduced IL-36 level which could make them more susceptible to airway infections as IL-36 is implicated in antimicrobial defense. This study showed also an implication of IL-36 and IL-23 in airway neutrophilic inflammation in chronic airway obstructive diseases., (Copyright © 2021 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Pulmonary fibrosis is a pathological entity still too little understood today, burdened with significant morbidity and mortality. Idiopathic pulmonary fibrosis is a complex diagnostic disease requiring a multidisciplinary approach and in some cases the performance of a lung biopsy. In addition, the early identification of the pathology remains the key in order to preserve lung function as much as possible. In this context and in view of the diagnostic difficulty, it seems essential to identify new biomarkers to help with the differential diagnosis, the evaluation of the prognosis and the response to treatment. In addition, the evolution of the pathology remaining inexorable despite anti-fibrotic treatments, it appears critical to be able to identify new potential therapeutic routes.

Background: Chlamydia pneumoniae and Mycoplasma pneumoniae have been implicated in the pathogenesis of asthma and are responsible for chronic inflammation when host immune system fails to eradicate the bacteria., Method: We performed a prospective study on 410 patients who underwent a visit at the asthma clinic of CHU of Liege between June 2016 and June 2018 with serology testing for C. pneumoniae and M. pneumoniae., Results: 65% of our asthmatic population had serum IgA and/or IgG towards C. pneumoniae, while only 12.6% had IgM and/or IgG against M. pneumoniae. Compared to seronegative asthmatics, asthmatics with IgA+ and IgG+ against C. pneumoniae were more often male and older with a higher proportion of patients with smoking history. They received higher doses of inhaled corticosteroids (ICS) and displayed lower FEV 1 /FVC ratio, higher RV/TLC ratio and lower conductance. They had higher levels of fibrinogen, though in the normal range and had lower sputum eosinophil counts. Patients with IgA- and IgG+ against C. pneumoniae were older and had higher blood monocyte counts and alpha-1-antitrypsin levels as compared to seronegative patients. Patients with IgM and/or IgG towards M. pneumoniae were more often males than seronegative asthmatics. In a subpopulation of 14 neutrophilic asthmatics with Chlamydia pneumoniae IgA + /IgG + treated with macrolides, we found a significant decrease in blood neutrophils and normalization of sputum neutrophil count but no effect on asthma quality of life and exacerbations., Conclusion: Positive Chlamydia serologic test is more common than positive Mycoplasma serology. Asthmatics with IgA and IgG against C. pneumoniae have more severe disease with increased airway obstruction, higher doses of ICS, more signs of air trapping and less type-2 inflammation.

Competing Interests: Prof. Dr Renaud Louis reports grants and/or personal fees from GSK, AZ, Novartis, Chiesi, and Sanofi, outside the submitted work. The authors report no other conflict of interest with this work.

Background and Objective: Airway remodeling, as many other factors, may lead to lung function decline and irreversible airflow obstruction (IRAO) in asthma. This study was undertaken in order to highlight predictors of incomplete reversibility of airflow obstruction in adult asthmatics to identify patients with poorer prognosis and improve their care, and decrease morbidity., Methods: A retrospective study was conducted in 973 asthmatics recruited from the University Asthma Clinic of Liege. Patients with IRAO (post-BD FEV 1 /FVC<0.7 & FEV 1 <80% predicted) were compared to patients with reversible airway obstruction (RAO) (post-BD FEV 1 /FVC≥0.7 & FEV 1 ≥80% predicted). TGF-β was measured in sputum supernatant of 85 patients., Results: Seventeen percent of asthmatics presented with IRAO. These patients were significantly older, more smokers, with a lower proportion of female, a longer disease duration, were more poorly controlled with a lower quality of life. This sub-population of asthmatics also showed more often elevated blood and sputum eosinophils and neutrophils, and higher exacerbation and hospitalisation rates in the previous year. The multivariable analysis revealed male gender, longer disease duration, cigarette smoking, ACQ score, sputum eosinophils and neutrophils, ICS dose and OCS maintenance, BMI, and asthma onset as variables independently linked to IRAO. Total TGF-β levels appeared higher in patients with IRAO (n = 38) compared to patients with RAO (n = 47)., Conclusion: These data show that risk factors for IRAO are male gender, smoking, a longer disease duration, uncontrolled asthma, eosinophilic or neutrophilic airway inflammation, lower BMI, and later asthma onset. Moreover, TGF-β levels are higher in IRAO., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Introduction: Asthma in obese subjects is poorly understood. According to GINA guidelines, pulmonologists increase ICS in case of poor asthma control but lung volume restriction may also worsen respiratory symptoms in obese asthmatics leading to overtreatment in this subpopulation., Methods: We conducted a retrospective study on 1217 asthmatics recruited from University Hospital of Liege. 92 patients with a BMI ≥30 came at least two times at the asthma clinic (mean interval: 335 days). In this obese population, we identified predictors of good (decrease in ACQ ≥0.5) versus poor response (rise in ACQ ≥0.5) to ICS step-up therapy., Results: Obese asthmatics had a poorer asthma control and quality of life as compared to non-obese and exhibited reduced FVC, higher levels of blood leucocytes and markers of systemic inflammation. The proportion of asthma inflammatory phenotypes was similar to that observed in a general population of asthmatics. Among uncontrolled obese asthmatics receiving ICS step-up therapy, 53% improved their asthma control while 31% had a worsening of their asthma. Uncontrolled obese asthmatics showing a good response to increase in ICS had higher ACQ, lower CRP levels, higher sputum eosinophil counts and higher FeNO levels at visit 1. Uncontrolled obese asthmatics that worsened after increasing the dose of ICS had lower FVC, lower sputum eosinophil counts and higher sputum neutrophil counts., Conclusion: We observed poorer asthma control in obese asthmatics despite similar bronchial inflammation. Managing obese asthmatics according to ACQ alone seems to underestimate asthma control and the contribution of restriction to dyspnea. Increasing the dose of ICS in the absence of sputum eosinophilic inflammation or in the presence of restriction or bronchial neutrophilia led to poorer asthma control. In those patients, management of obesity should be the first choice., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Systemic sclerosis (SSc) is a rare connective tissue disease associated with rapid evolving interstitial lung disease (SSc-ILD), driving its mortality. Specific biomarkers associated with the evolution of the lung disease are highly needed. We aimed to identify specific biomarkers of SSc-ILD to predict the evolution of the disease. Nucleosomes are stable DNA/protein complexes that are shed into the blood stream making them ideal candidates for biomarkers., Methods: We studied circulating cell-free nucleosomes (cf-nucleosomes) in SSc patients, 31 with ILD (SSc-ILD) and 67 without ILD. We analyzed plasma levels for cf-nucleosomes and investigated whether global circulating nucleosome levels in association with or without other biomarkers of interest for systemic sclerosis or lung fibrosis (e.g., serum growth factors: IGFBP-1 and the MMP enzyme: MMP-9), could be suitable potential biomarkers for the correct identification of SSc-ILD disease., Results: We found that H3.1 nucleosome levels were significantly higher in patients with SSc-ILD compared SSc patients without ILD (p < 0.05) and levels of MMP-9 were significantly increased in patients with SSc-ILD compared to SSc patients without ILD (p < 0.05). Conversely, IGFBP-1 was significantly reduced in patients with SSc-ILD compared to SSc without ILD (p < 0.001). The combination of cf-nucleosomes H3.1 coupled to MMP-9 and IGFBP-1 increased the sensitivity for the differential detection of SSc-ILD. High levels of accuracy were reached with this combined model: its performances are strong with 68.4% of positive predictive value and 77.2% of negative predictive value for 90% of specificity. With our model, we identified a significant negative correlation with FVC % pred (r = -0.22) and TLC % pred (r = -0.31). The value of our model at T1 (baseline) has a predictive power over the Rodnan score at T2 (after 6-18 months), showed by a significant linear regression with R 2 = 19% (p = 0.013). We identified in the sole group of SSc-ILD patients a significant linear regression with a R 2 = 54.4% with the variation of DLCO between T1 and T2 (p < 0.05)., Conclusion: In our study, we identified a new blood-based model with nucleosomic biomarker in order to diagnose SSc-ILD in a SSc cohort. This model is correlated with TLC and FVC at baseline and predictive of the skin evolution and the DLCO. Further longitudinal exploration studies should be performed in order to evaluate the potential of such diagnostic and predictive model.

Background: Randomized control trials performed in selected populations of severe eosinophilic asthmatics have shown that mepolizumab, an anti-IL5 therapy, was able to reduce exacerbations and OCS maintenance dose and in some studies, to improve asthma control and lung function., Objective: The aim of this study was to confirm the results of the RCTs in real-life in a population of 116 severe eosinophilic asthmatics treated with mepolizumab and who were followed up at the asthma clinic every month for at least 18 months. Severe asthmatics underwent FENO, lung function, asthma control and quality of life questionnaires, sputum induction and gave a blood sample at baseline, after 6 months and then every year., Results: We found a significant reduction in exacerbations by 85% after 6 months (P < .0001), which was maintained over time. We also found a significant and maintained reduction by 50% in the dose of oral corticosteroids (P < .001). Patients improved their ACT (+5.31pts, p<0.0001) ACQ (-1.13pts, P < .0001) and their AQLQ score (+1.24, P < .0001) at 6 months and this was maintained during follow-up. Only 37% reached asthma control (ACQ <1.5, ACT> 20). We observed a progressive increase in post-BD FEV1 that reached significance after 18 months (190ml or 11%, P < .01). Patients improving their FEV1had higher baseline sputum eosinophils than those not improving airway caliber. We found a significant reduction in sputum eosinophil counts by 60% after 6 months (P < .01) and a maintained reduction in blood eosinophil counts by 98% (P < .0001)., Conclusion: In our real-life study, we confirm the results published in the RCTs showing a sharp reduction in exacerbation and oral corticosteroids dose and an improvement in asthma control and quality of life., Clinical Relevance: Mepolizumab is efficient in severe eosinophilic asthma in real life., (© 2020 John Wiley & Sons Ltd.)

Within the non-coding genome landscape, long non-coding RNAs (lncRNAs) and their secretion within exosomes are a window that could further explain the regulation, the sustaining, and the spread of lung diseases. We present here a compilation of the current knowledge on lncRNAs commonly found in Chronic Obstructive Pulmonary Disease (COPD), asthma, Idiopathic Pulmonary Fibrosis (IPF), or lung cancers. We built interaction networks describing the mechanisms of action for COPD, asthma, and IPF, as well as private networks for H19, MALAT1, MEG3, FENDRR, CDKN2B-AS1, TUG1, HOTAIR, and GAS5 lncRNAs in lung cancers. We identified five signaling pathways targeted by these eight lncRNAs over the lung diseases mentioned above. These lncRNAs were involved in ten treatment resistances in lung cancers, with HOTAIR being itself described in seven resistances. Besides, five of them were previously described as promising biomarkers for the diagnosis and prognosis of asthma, COPD, and lung cancers. Additionally, we describe the exosomal-based studies on H19, MALAT1, HOTAIR, GAS5, UCA1, lnc-MMP2-2, GAPLINC, TBILA, AGAP2-AS1, and SOX2-OT. This review concludes on the need for additional studies describing the lncRNA mechanisms of action and confirming their potential as biomarkers, as well as their involvement in resistance to treatment, especially in non-cancerous lung diseases.

Induced sputum is a non-invasive method of collecting cells from airways. Gene expression analysis from sputum cells has been used to understand the underlying mechanisms of airway diseases such as asthma or chronic obstructive pulmonary disease (COPD). Suitable reference genes for normalisation of target mRNA levels between sputum samples have not been defined so far.The current study assessed the expression stability of nine common reference genes in sputum samples from 14 healthy volunteers, 12 asthmatics and 12 COPD patients.Using three different algorithms (geNorm, NormFinder and BestKeeper), we identified HPRT1 and GNB2L1 as the most optimal reference genes to use for normalisation of quantitative reverse transcriptase (RT) PCR data from sputum cells. The higher expression stability of HPRT1 and GNB2L1 were confirmed in a validation set of patients including nine healthy controls, five COPD patients and five asthmatic patients. In this group, the RNA extraction and RT-PCR methods differed, which attested that these genes remained the most reliable whatever the method used to extract the RNA, generate complementary DNA or amplify it.Finally, an example of relative quantification of gene expression linked to eosinophils or neutrophils provided more accurate results after normalisation with the reference genes identified as the most stable compared to the least stable and confirmed our findings., Competing Interests: Conflict of interest: C. Moermans has nothing to disclose. Conflict of interest: E. Deliege has nothing to disclose. Conflict of interest: D. Pirottin has nothing to disclose. Conflict of interest: C. Poulet has nothing to disclose. Conflict of interest: J. Guiot has nothing to disclose. Conflict of interest: M. Henket has nothing to disclose. Conflict of interest: J. da Silva has nothing to disclose. Conflict of interest: R. Louis reports grants from GSK and Chiesi, grants and personal fees from Novartis, personal fees from AstraZeneca, outside the submitted work., (Copyright ©ERS 2019.)

SSc is a rare disease of unknown origin associated with multiple organ involvement. One of the major complications that drives the mortality of SSc patients is interstitial lung disease. The course of SSc-interstitial lung disease progression has a wide spectrum. Since the treatment is based on aggressive immunosuppression it should not be given to stable or non-progressing disease. The correct identification of disease with high risk of progression remains a challenge for early therapeutic intervention, and biomarkers remain urgently needed. In fact, eight categories of biomarkers have been identified and classified according to the different biological pathways involved. The purpose of this article is to describe the main biomarkers thought to be of interest with clinical value in the diagnosis and prognosis of SSc-interstitial lung disease., (© The Author(s) 2019. Published by Oxford University Press on behalf of the British Society for Rheumatology.)

Rationale: Analysis of exhaled breath for asthma phenotyping using endogenously generated volatile organic compounds (VOCs) offers the possibility of noninvasive diagnosis and therapeutic monitoring. Induced sputum is indeed not widely available and markers of neutrophilic asthma are still lacking. Objectives: To determine whether analysis of exhaled breath using endogenously generated VOCs can be a surrogate marker for recognition of sputum inflammatory phenotypes. Methods: We conducted a prospective study on 521 patients with asthma recruited from the University Asthma Clinic of Liege. Patients underwent VOC measurement, fraction of exhaled nitric oxide (Fe NO ) spirometry, sputum induction, and gave a blood sample. Subjects with asthma were classified in three inflammatory phenotypes according to their sputum granulocytic cell count. Measurements and Main Results: In the discovery study, seven potential biomarkers were highlighted by gas chromatography-mass spectrometry in a training cohort of 276 patients with asthma. In the replication study ( n  = 245), we confirmed four VOCs of interest to discriminate among asthma inflammatory phenotypes using comprehensive two-dimensional gas chromatography coupled to high-resolution time-of-flight mass spectrometry. Hexane and 2-hexanone were identified as compounds with the highest classification performance in eosinophilic asthma with accuracy comparable to that of blood eosinophils and Fe NO . Moreover, the combination of Fe NO , blood eosinophils, and VOCs gave a very good prediction of eosinophilic asthma (area under the receiver operating characteristic curve, 0.9). For neutrophilic asthma, the combination of nonanal, 1-propanol, and hexane had a classification performance similar to Fe NO or blood eosinophils in eosinophilic asthma. Those compounds were found in higher levels in neutrophilic asthma. Conclusions: Our study is the first attempt to characterize VOCs according to sputum granulocytic profile in a large population of patients with asthma and provide surrogate markers for neutrophilic asthma.

The technique of sputum induction and processing is a recognized non-invasive method allowing the collection and analysis of cells from the airways, which is interesting in various respiratory diseases like asthma, chronic obstructive pulmonary disease (COPD), chronic cough, or idiopathic pulmonary fibrosis. This technique is well tolerated, safe and non-invasive, but is currently limited to research services and specialized centers in clinical practice because it is technically demanding, time-consuming, and requires trained staff. The success rate of sputum induction and analysis is about 80%. Here, we describe the induction and laboratory processing of sputum samples. Sputum is induced by inhalation of hypertonic or isotonic saline with salbutamol. For the processing, we use the whole sputum technique. Dithiothreitol (DTT) is used to allow mucolysis of sputum samples. The primary aim of sputum processing is to obtain a differential cell count to study the cell types present in the airway lumen. Additional analyses may also be performed on sputum supernatant and sputum cells, which may allow further investigation into inflammatory processes and immune mechanisms. Examples include studying mediators in sputum supernatant and performing a large spectrum of analysis on sputum cells such as flow cytometry, genomics, or proteomics. Finally, representative results of sputum analysis in healthy controls, asthmatics, and COPD patients are presented.

This review focuses on the role of the lung microbiome in idiopathic pulmonary fibrosis. Although historically considered sterile, bacterial communities have now been well documented in lungs both in healthy and pathological conditions. Studies in idiopathic pulmonary fibrosis (IPF) suggest that increased bacterial burden and/or abundance of potentially pathogenic bacteria may drive disease progression, acute exacerbations, and mortality. More recent work has highlighted the interaction between the lung microbiome and the innate immune system in IPF, strengthening the argument for the role of both host and environment interaction in disease pathogenesis. Existing published data suggesting that the lung microbiome may represent a therapeutic target, via antibiotic administration, immunization against pathogenic organisms, or treatment directed at gastroesophageal reflux. Taken altogether, published literature suggests that the lung microbiome might serve in the future as a prognostic biomarker, a therapeutic target, and/or provide an explanation for disease pathogenesis in IPF., Competing Interests: The authors declare no conflict of interest.