Real-Life Response to Biologics in Severe Asthma with Nasal Polyposis: Insights from the Belgian Severe Asthma Registry.

BACKGROUND: Nasal polyposis (NP) is a comorbidity of type 2 severe asthma (SA) which could influence response to SA biologics. METHODS: We evaluated (super-) response in SA patients with (NP +) and without NP (NP-) enrolled in the Belgian Severe Asthma Registry (BSAR). RESULTS: 914 patients, of whom 31% NP + , were included. At enrollment, NP + patients had higher annual exacerbation rates, higher number of emergency room visits and more elevated type 2 biomarkers. In the longitudinal subanalysis of 104 patients, both groups had significant and similar asthma responses to asthma biologics, except for a greater increase in FEV1 in the NP + group. Super-response was achieved in 33 patients (32%), irrespective of NP status or type of biologic. CONCLUSION: In conclusion, both NP + and NP - patients had positive treatment responses, with some able to achieve super-response. In SA patients with NP, a greater FEV1 improvement as compared to SA patients without NP was observed.

Disruption of GCN2 Pathway Aggravates Vascular and Parenchymal Remodeling during Pulmonary Fibrosis.

Pulmonary fibrosis (PF) and pulmonary hypertension (PH) are chronic diseases of the pulmonary parenchyma and circulation, respectively, which may coexist, but underlying mechanisms remain elusive. Mutations in the GCN2 (general control nonderepressible 2) gene (EIF2AK4 [eukaryotic translation initiation factor 2 alpha kinase 4]) were recently associated with pulmonary veno-occlusive disease. The aim of this study is to explore the involvement of the GCN2/eIF2α (eukaryotic initiation factor 2α) pathway in the development of PH during PF, in both human disease and in a laboratory animal model. Lung tissue from patients with PF with or without PH was collected at the time of lung transplantation, and control tissue was obtained from tumor resection surgery. Experimental lung disease was induced in either male wild-type or EIF2AK4-mutated Sprague-Dawley rats, randomly receiving a single intratracheal instillation of bleomycin or saline. Hemodynamic studies and organ collection were performed 3 weeks after instillation. Only significant results (P < 0.05) are presented. In PF lung tissue, GCN2 protein expression was decreased compared with control tissue. GCN2 expression was reduced in CD31+ endothelial cells. In line with human data, GCN2 protein expression was decreased in the lung of bleomycin rats compared with saline. EIF2AK4-mutated rats treated with bleomycin showed increased parenchymal fibrosis (hydroxyproline concentrations) and vascular remodeling (media wall thickness) as well as increased right ventricular systolic pressure compared with wild-type animals. Our data show that GCN2 is dysregulated in both humans and in an animal model of combined PF and PH. The possibility of a causative implication of GCN2 dysregulation in PF and/or PH development should be further studied.

Development of Core Outcome Measures sets for paediatric and adult Severe Asthma (COMSA).

BACKGROUND: Effectiveness studies with biological therapies for asthma lack standardised outcome measures. The COMSA (Core Outcome Measures sets for paediatric and adult Severe Asthma) Working Group sought to develop Core Outcome Measures (COM) sets to facilitate better synthesis of data and appraisal of biologics in paediatric and adult asthma clinical studies. METHODS: COMSA utilised a multi-stakeholder consensus process among patients with severe asthma, adult and paediatric clinicians, pharmaceutical representatives, and health regulators from across Europe. Evidence included a systematic review of development, validity and reliability of selected outcome measures plus a narrative review and a pan-European survey to better understand patients' and carers' views about outcome measures. It was discussed using a modified GRADE (Grading of Recommendations Assessment, Development and Evaluation) Evidence to Decision framework. Anonymous voting was conducted using predefined consensus criteria. RESULTS: Both adult and paediatric COM sets include forced expiratory volume in 1 s (FEV1) as z-scores, annual frequency of severe exacerbations and maintenance oral corticosteroid use. Additionally, the paediatric COM set includes the Paediatric Asthma Quality of Life Questionnaire and Asthma Control Test or Childhood Asthma Control Test, while the adult COM set includes the Severe Asthma Questionnaire and Asthma Control Questionnaire-6 (symptoms and rescue medication use reported separately). CONCLUSIONS: This patient-centred collaboration has produced two COM sets for paediatric and adult severe asthma. It is expected that they will inform the methodology of future clinical trials, enhance comparability of efficacy and effectiveness of biological therapies, and help assess their socioeconomic value. COMSA will inform definitions of non-response and response to biological therapy for severe asthma.

Activation of immune cell proteasomes in peripheral blood of smokers and COPD patients: implications for therapy.

BACKGROUND: Immune cells contain a specialised type of proteasome, i.e. the immunoproteasome, which is required for intracellular protein degradation. Immunoproteasomes are key regulators of immune cell differentiation, inflammatory activation and autoimmunity. Immunoproteasome function in peripheral immune cells might be altered by smoking and in chronic obstructive pulmonary disease (COPD), thereby affecting immune cell responses. METHODS: We analysed the expression and activity of proteasome complexes in peripheral blood mononuclear cells (PBMCs) isolated from healthy male young smokers as well as from patients with severe COPD and compared them with matching controls. RESULTS: Proteasome expression was upregulated in COPD patients as assessed by quantitative reverse transcriptase-PCR and mass spectrometry-based proteomic analysis. Proteasome activity was quantified using activity-based probes and native gel analysis. We observed distinct activation of immunoproteasomes in the peripheral blood cells of young male smokers and severely ill COPD patients. Native gel analysis and linear regression modelling confirmed robust activation and elevated assembly of 20S proteasomes, which correlated significantly with reduced lung function parameters in COPD patients. The immunoproteasome was distinctly activated in COPD patients upon inflammatory cytokine stimulation of PBMCs in vitro. Inhibition of the immunoproteasome reduced pro-inflammatory cytokine expression in COPD-derived blood immune cells. CONCLUSIONS: Given the crucial role of chronic inflammatory signalling and the emerging involvement of autoimmune responses in COPD, therapeutic targeting of the immunoproteasome might represent a novel therapeutic concept for COPD.

Effects of repeated infections with non-typeable Haemophilus influenzae on lung in vitamin D deficient and smoking mice.

BACKGROUND: In chronic obstructive pulmonary disease (COPD), exacerbations cause acute inflammatory flare-ups and increase the risk for hospitalization and mortality. Exacerbations are common in all disease stages and are often caused by bacterial infections e.g., non-typeable Heamophilus influenzae (NTHi). Accumulating evidence also associates vitamin D deficiency with the severity of COPD and exacerbation frequency. However, it is still unclear whether vitamin D deficiency when combined with cigarette smoking would worsen and prolong exacerbations caused by repeated infections with the same bacterial strain. METHODS: Vitamin D sufficient (VDS) and deficient (VDD) mice were exposed to nose-only cigarette smoke (CS) for 14 weeks and oropharyngeally instilled with NTHi at week 6, 10 and 14. Three days after the last instillation, mice were assessed for lung function, tissue remodeling, inflammation and immunity. The impact of VDD and CS on inflammatory cells and immunoglobulin (Ig) production was also assessed in non-infected animals while serum Ig production against NTHi and dsDNA was measured in COPD patients before and 1 year after supplementation with Vitamin D3. RESULTS: VDD enhanced NTHi eradication, independently of CS and complete eradication was reflected by decreased anti-NTHi Ig's within the lung. In addition, VDD led to an increase in total lung capacity (TLC), lung compliance (Cchord), MMP12/TIMP1 ratio with a rise in serum Ig titers and anti-dsDNA Ig's. Interestingly, in non-infected animals, VDD exacerbated the CS-induced anti-NTHi Ig's, anti-dsDNA Ig's and inflammatory cells within the lung. In COPD patients, serum Ig production was not affected by vitamin D status but anti-NTHi IgG increased after vitamin D3 supplementation in patients who were Vitamin D insufficient before treatment. CONCLUSION: During repeated infections, VDD facilitated NTHi eradication and resolution of local lung inflammation through production of anti-NTHi Ig, independently of CS whilst it also promoted autoantibodies. In COPD patients, vitamin D supplementation could be protective against NTHi infections in vitamin D insufficient patients. Future research is needed to decipher the determinants of dual effects of VDD on adaptive immunity. TRAIL REGISTRATION: ClinicalTrials, NCT00666367. Registered 23 April 2008, https://www.clinicaltrials.gov/ct2/show/study/NCT00666367 .

Increased Angiotensin-Converting Enzyme 2 and Loss of Alveolar Type II Cells in COVID-19-related Acute Respiratory Distress Syndrome.

Rationale: ACE2 (angiotensin-converting enzyme 2), the entry receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is expressed in type 2 alveolar epithelial cells (AT2) that may play key roles in postinjury repair. An imbalance between ACE2 and ACE has also been hypothesized to contribute to lung injury. Objectives: To characterize the expression and distribution of ACE2 and ACE and to compare AT2 with endothelial cell expression in coronavirus disease (COVID-19)-related or -unrelated acute respiratory distress syndrome (ARDS) and controls. Methods: Lung tissue stainings (using multiplex immunofluorescence) and serum concentrations of ACEs were determined retrospectively in two different cohorts of patients. AT2 and endothelial cells were stained in lung tissue for ProSPC (pro-surfactant protein C) and CD31, respectively. Measurements and Main Results: Pulmonary ACE2 expression was increased in patients with COVID-19-related and -unrelated ARDS (0.06% of tissue area and 0.12% vs. 0.006% for control subjects; P = 0.013 and P < 0.0001, respectively). ACE2 was upregulated in endothelial cells (0.32% and 0.53% vs. 0.01%; P = 0.009 and P < 0.0001) but not in AT2 cells (0.13% and 0.08% vs. 0.03%; P = 0.94 and P = 0.44). Pulmonary expression of ACE was decreased in both COVID-19-related and -unrelated ARDS (P = 0.057 and P = 0.032). Similar increases in ACE2 and decreases in ACE were observed in sera of COVID-19 (P = 0.0054 and P < 0.0001) and non-COVID-19 ARDS (P < 0.0001 and P = 0.016). In addition, AT2 cells were decreased in patients with COVID-19-related ARDS compared with COVID-19-unrelated ARDS (1.395% vs. 2.94%, P = 0.0033). Conclusions: ACE2 is upregulated in lung tissue and serum of both COVID-19-related and -unrelated ARDS, whereas a loss of AT2 cells is selectively observed in COVID-19-related ARDS.

Determinants of IgG antibodies kinetics after severe and critical COVID-19.

The kinetics of IgG antibodies after coronavirus disease 2019 (COVID-19) remain poorly understood. We investigated factors influencing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG antibody levels and time to seronegativation during the follow-up of severe and critically ill patients. We retrospectively reviewed serological evaluations drawn during the follow-up of severe or critical laboratory-proven COVID-19 patients hospitalized at a large academic hospital. Specific IgG titers were measured using a chemiluminescent assay targeting anti-spike and anti-nucleocapsid protein IgG. The influence of time, demographic factors, clinical and paraclinical characteristics, and COVID-19 therapeutics on IgG levels were assessed through linear regression using a mixed-effect model, and delay until IgG negativation through a Weibull regression model. The cohort included 116 patients with a total of 154 IgG measurements drawn at a median of 79 days after diagnosis. IgG antibodies were increased with age (p = 0.005) and decreased significantly over time (p = 0.0002). Using elapsed time and age as covariates, we demonstrated higher IgG levels in patients with a higher body mass index (BMI) (p = 0.0026) and lower IgG levels in immunocompromised patients (p = 0.032). A high BMI was further found to delay and immunodeficiency to hasten significantly seronegativation, whereas no significant effect was observed with corticosteroids. These data highlight the waning over time of IgG antibodies after severe or critical COVID-19. Age, BMI, and immunosuppression also appear to influence the IgG kinetics, while short-term corticotherapy does not. Those data improve the understanding of SARS-CoV-2 serology while further research should determine the determinants of long-term seroprotection.

Severe asthma: oral corticosteroid alternatives and the need for optimal referral pathways.

OBJECTIVE: Patients with severe asthma require high-dose inhaled corticosteroids, with or without add-on treatments, to maintain asthma control. Because symptom control remains unsatisfactory in some patients despite these therapies, maintenance therapy with oral corticosteroids (OCS) remains considered a treatment option by physicians. Besides physician-diagnosed exacerbations, many patients intermittently self-medicate with OCS during episodes of worsening symptoms or as a prevention of such episodes. However, long-term OCS use is associated with several comorbidities that may decrease health-related quality of life, worsen prognosis, and should ideally require monitoring and management. In this review, we discuss the adverse effects of OCS use, the OCS-sparing effect of biologics in severe asthma, and the need for optimal referral pathways to ensure the best outcomes for those at-risk asthma patients. DATA SOURCES: PubMed. STUDY SELECTION: Studies with results on the OCS-sparing effect of biologics in adult severe asthma were selected. RESULTS: Chronic and intermittent OCS use in asthma is associated with considerable adverse effects in asthma. Omalizumab, mepolizumab, benralizumab, and dupilumab reduce the need for OCS in severe asthma, while also reducing the exacerbation rate and improving several patient-related outcomes. CONCLUSION: Targeted biologic therapies have revolutionized the treatment of uncontrolled severe asthma by reducing or even eliminating the need for OCS and improving other major outcomes. Novel agents are now rapidly increasing the therapeutic armamentarium, but additional efforts are needed to optimize referral pathways in order to ensure sustainable access to these therapies.

Key role of the epithelium in chronic upper airways diseases.

The respiratory epithelium of the upper airways is a first-line defence against inhaled irritants, pathogens and allergens. It ensures a physical barrier provided by apical junctions and mucociliary clearance to avoid excessive activation of the immune system. The epithelium also forms a chemical and immunological barrier, extensively equipped to protect the airways against external aggressions before the adaptive immune system is required. Under normal circumstances, the epithelium is capable of recovering rapidly after damage. This manuscript reviews these main properties of the upper airway epithelium as well as its reported impairments in chronic inflammatory diseases. The knowledge on normal epithelial functions and their dysregulation in upper airway diseases should help to design new epithelial-targeted treatments.

Real-Life Study of Mepolizumab in Idiopathic Chronic Eosinophilic Pneumonia.

INTRODUCTION: Idiopathic chronic eosinophilic pneumonia (ICEP) is an orphan lung disease characterized by concomitant systemic and local eosinophilia, along with bilateral lung infiltrates. Symptoms include dyspnea of subacute/chronic onset, cough, and general systemic signs. Although all patients do respond to oral corticosteroids, relapse rate is very high, which highlights the need for alternative therapies in case of relapsing ICEP. Mepolizumab is a fully humanized antibody directed against interleukin 5, a key growth factor of eosinophils. In the present study, we retrospectively studied the effect of off-label use of mepolizumab for relapsing ICEP. MATERIALS AND METHODS: All data from patients treated with mepolizumab for relapsing ICEP were included in our database and diagnoses were reviewed. We analyzed the effect of treatment on relapse rate, oral corticosteroids (OCS) use, and lung lesions on high-resolution computed tomography (HRCT). RESULTS: We included ten patients in the final analysis, with a median follow-up of 9 months after initiation of mepolizumab. Beside its expected effect on circulating eosinophils, treatment with mepolizumab was associated with a significant reduction of annual rate of exacerbations and a reduced consumption of corticosteroids. We also observed a remission of lung lesions on follow-up HRCT. CONCLUSIONS: In this open-label retrospective study, treatment of ICEP with mepolizumab was associated with a reduction of relapses, OCS use, and the disappearance of lung infiltrates.

Increased IgA Expression in Lung Lymphoid Follicles in Severe Chronic Obstructive Pulmonary Disease.

RATIONALE: Accumulation of B cells and lymphoid follicles (LFs) has been described in chronic obstructive pulmonary disease (COPD) airways, but the functional status of lung B cells remains poorly known. OBJECTIVES: To characterize LFs for expression of IgA, the main mucosal antibody. METHODS: The presence of B cells and LFs, including intrafollicular IgA expression, were determined in the lung from patients with COPD (n = 37) versus control subjects (n = 34) by immunohistochemistry. We also evaluated follicular IgA responses in the lungs from mice infected with Pseudomonas aeruginosa (PAO1) (n = 10 per group) and in smoking mice. MEASUREMENTS AND MAIN RESULTS: Whereas in smokers B-cell numbers slightly increased, robust increases in B-cell and LF numbers (mainly in distal airways) were only observed in severe COPD. Most follicular B cells were IgM+ (70-80%), but IgA+ (and not IgG+) B-cell numbers were increased in LFs from severe COPD compared with control subjects (twofold, 44.7% vs. 25.2%), and this was significant in distal but not proximal airways. Follicular IgA response was also observed in PAO1-infected mouse lungs, but not after smoke exposure. Moreover, follicular IgA expression associated with expression of IL-21, which was very potent to activate immunoglobulin production in vitro. CONCLUSIONS: This study shows that IgA production occurs in peribronchiolar LFs from severe COPD, where IL-21-producing T cells are present, and presumably represents a feature of exacerbated mucosal adaptive immune responses against microbial and/or self-antigens.

Bronchial Epithelial IgA Secretion Is Impaired in Asthma. Role of IL-4/IL-13.

RATIONALE: Asthma is associated with increased lung IgE production, but whether the secretory IgA system is affected in this disease remains unknown. OBJECTIVES: We explored mucosal IgA transport in human asthma and its potential regulation by T-helper cell type 2 inflammation. METHODS: Bronchial biopsies from asthma and control subjects were assayed for bronchial epithelial polymeric immunoglobulin receptor (pIgR) expression and correlated to T-helper cell type 2 biomarkers. Bronchial epithelium reconstituted in vitro from these subjects, on culture in air-liquid interface, was assayed for pIgR expression and regulation by IL-4/IL-13. MEASUREMENTS AND MAIN RESULTS: Downregulation of pIgR protein was observed in the bronchial epithelium from patients with asthma (P = 0.0002 vs. control subjects). This epithelial defect was not observed ex vivo in the cultured epithelium from patients with asthma. Exogenous IL-13 and IL-4 could inhibit pIgR expression and IgA transcytosis. Mechanistic experiments showed that autocrine transforming growth factor-ß mediates the IL-4/IL-13 effect on the pIgR, with a partial contribution of upregulated transforming growth factor-α/epidermal growth factor receptor. CONCLUSIONS: This study shows impaired bronchial epithelial pIgR expression in asthma, presumably affecting secretory IgA-mediated frontline defense as a result of type 2 immune activation of the transforming growth factor pathway.

Aberrant epithelial differentiation by cigarette smoke dysregulates respiratory host defence.

It is currently unknown how cigarette smoke-induced airway remodelling affects highly expressed respiratory epithelial defence proteins and thereby mucosal host defence.Localisation of a selected set of highly expressed respiratory epithelial host defence proteins was assessed in well-differentiated primary bronchial epithelial cell (PBEC) cultures. Next, PBEC were cultured at the air-liquid interface, and during differentiation for 2-3 weeks exposed daily to whole cigarette smoke. Gene expression, protein levels and epithelial cell markers were subsequently assessed. In addition, functional activities and persistence of the cigarette smoke-induced effects upon cessation were determined.Expression of the polymeric immunoglobulin receptor, secretory leukocyte protease inhibitor and long and short PLUNC (palate, lung and nasal epithelium clone protein) was restricted to luminal cells and exposure of differentiating PBECs to cigarette smoke resulted in a selective reduction of the expression of these luminal cell-restricted respiratory host defence proteins compared to controls. This reduced expression was a consequence of cigarette smoke-impaired end-stage differentiation of epithelial cells, and accompanied by a significant decreased transepithelial transport of IgA and bacterial killing.These findings shed new light on the importance of airway epithelial cell differentiation in respiratory host defence and could provide an additional explanation for the increased susceptibility of smokers and patients with chronic obstructive pulmonary disease to respiratory infections.

Airway Epithelium Dysfunction in Cystic Fibrosis and COPD.

Cystic fibrosis is a genetic disease caused by mutations in the CFTR gene, whereas chronic obstructive pulmonary disease (COPD) is mainly caused by environmental factors (mostly cigarette smoking) on a genetically susceptible background. Although the etiology and pathogenesis of these diseases are different, both are associated with progressive airflow obstruction, airway neutrophilic inflammation, and recurrent exacerbations, suggesting common mechanisms. The airway epithelium plays a crucial role in maintaining normal airway functions. Major molecular and morphologic changes occur in the airway epithelium in both CF and COPD, and growing evidence suggests that airway epithelial dysfunction is involved in disease initiation and progression in both diseases. Structural and functional abnormalities in both airway and alveolar epithelium have a relevant impact on alteration of host defences, immune/inflammatory response, and the repair process leading to progressive lung damage and impaired lung function. In this review, we address the evidence for a critical role of dysfunctional airway epithelial cells in chronic airway inflammation and remodelling in CF and COPD, highlighting the common mechanisms involved in the epithelial dysfunction as well as the similarities and differences of the two diseases.

Interleukin-1α induced release of interleukin-8 by human bronchial epithelial cells in vitro: assessing mechanisms and possible treatment options.

Survival after lung transplantation is hampered by chronic lung allograft dysfunction (CLAD). Persistently elevated BAL-neutrophilia is observed in some patients despite treatment with azithromycin, which may be induced by IL-1α. Our aim is to establish an in vitro model, assess mechanistic pathways and test different therapeutic strategies of IL-1α-induced release of IL-8 by human bronchial epithelial cells. Bronchial epithelial cells (16HBE) were stimulated with IL-1α with or without azithromycin or dexamethasone. IL-8 protein was analyzed in cell supernatant. Different MAP kinases (p38, JNK, ERK1/2 , Iκß) and targets known to be involved in tumor formation (PI3K, Akt) were investigated. Finally, different treatment options were tested for their potential inhibitory effect. IL-1α induced IL-8 in bronchial epithelial cells, which was dose-dependently inhibited by dexamethasone but not by azithromycin. IL-1α induced p38 and Akt phosphorylation, but activation of these MAPK was not inhibited by dexamethasone. JNK, ERK1/2 , Iκß and PI3K were not activated. None of the tested drugs reduced the IL-1α induced IL-8 production. We established an in vitro model wherein steroids inhibit the IL-1α-induced IL-8 production, while azithromycin was ineffective. Despite using this simple in vitro model, we could not identify a new treatment option for azithromycin-resistant airway neutrophilia.

Asthma phenotypes and IgE responses.

The discovery of IgE represented a major breakthrough in allergy and asthma research, whereas the clinical interest given to IgE in asthma has been blurred until the arrival of anti-IgE biotherapy. Novel facets of the complex link between IgE and asthma have been highlighted by the effect of this treatment and by basic research. In parallel, asthma phenotyping recently evolved to the concept of endotypes, relying on identified/suspected pathobiological mechanisms to phenotype patients, but has not yet clearly positioned IgE among biomarkers of asthma.In this review, we first summarise recent knowledge about the regulation of IgE production and its main receptor, FcεRI. In addition to allergens acting as classical IgE inducers, viral infections as well as air pollution may trigger the IgE pathway, notably resetting the threshold of IgE sensitivity by regulating FcεRI expression. We then analyse the place of IgE in different asthma endo/phenotypes and discuss the potential interest of IgE among biomarkers in asthma.

Persistence of asthma following allergen avoidance is associated with proTh2 myeloid dendritic cell activation.

BACKGROUND: The natural history of asthma includes in some patients periods of disease remission, but the underlying mechanisms are unknown. OBJECTIVES: We explored whether type 1 myeloid dendritic cell (mDC) dysfunction could be involved in the persistence of asthma, studying the controlled setting of occupational asthma after allergen avoidance. METHODS: We recruited 32 patients with occupational asthma to flour or latex ascertained by specific inhalation challenge and who were no longer exposed to the causal allergen. Leukapheresis was performed in each patient to isolate and characterise blood type 1 mDCs, and their functionality was studied in coculture with allogeneic CD4(+) T cells from controls. RESULTS: At follow-up, 11/32 patients (34%) were characterised by the absence of symptoms and non-specific bronchial hyper-responsiveness to histamine and were considered to be cured. When compared with cured patients, mDCs from patients with persistent disease increased the production of interleukin (IL) 5 and IL-13 by CD4(+) T cells, and upregulated programmed death ligand 2 (PD-L2) upon allergen pulsing. In addition, IL-5 and IL-13 responses could be reversed by exogenous IL-12, as well as by PD-L2 blockade. CONCLUSIONS: This study indicates that pro-Th2 features of mDCs correlate with disease activity in asthma after cessation of exposure to the causal allergen. The findings also highlight that the Th2 programming by dendritic cells is flexible and partly mediated by PD-L2.