Increased Muc5AC and Decreased Ciliated Cells in Severe Asthma Partially Restored by Inhibition of IL-4Rα Receptor.

BACKGROUND: The role of IL-13 on the airway epithelium in severe asthma leading to airway remodeling remains poorly understood. OBJECTIVE: To study IL-13 induced airway remodeling on goblet cells and cilia in the airway epithelium in severe asthma and the impact of an anti-IL4Rα antibody, dupilumab, in vitro. METHODS: Quantitative CT (qCT) lungs and endobronchial biopsies and brushings were obtained in 51 participants (22 severe, 11 non-severe asthma and 18 healthy participants) in the Severe Asthma Research Program (SARPIII) and measured for mucin and cilia related proteins. Epithelial cells were differentiated in air-liquid interphase (ALI) with IL-13 +/-dupilumab and assessed for mucin, cilia, cilia beat frequency (CBF) and epithelial integrity (transepithelial electrical resistance, TEER). RESULTS: Increased Muc5AC (Δ+263.2±92.7 lums/EpiArea) and decreased ciliated cells (Δ-0.07±0.03 Foxj1+cells/EpiArea) were observed in biopsies from severe asthma when compared to healthy (p<0.01 and p=0.047 respectively). RNAseq of epithelial cell brushes confirmed a Muc5AC increase with a decrease in a 5-gene cilia-related mean in severe asthma compared to healthy (all p<0.05). IL-13 (5 ng/mL) differentiated ALI cultures of healthy and asthmatic (severe and non-severe participants) increased Muc5AC, decreased cilia (α-acytl-tubulin) in healthy (Δ+6.5±1.5%, Δ-14.1±2.7%; all p<0.001 respectively) and asthma (Δ+4.4±2.5%, Δ-13.1±2.7%; p=0.084, p<0.001 respectively); decreased epithelial integrity (TEER) in healthy (-140.9±21.3 [ohms], p<0.001) while decreasing CBF in asthma (Δ-4.4±1.7 [Hz], p<0.01). When dupilumab was added to ALI with IL-13, there was no significant decrease in Mu5AC but there was restoration of cilia in healthy and asthma participants (absolute increase of 67.5% and 32.5% cilia, all p<0.05 respectively) while CBF increased (Δ+3.6±1.1 [Hz], p<0.001) and TEER decreased (only in asthma Δ-37.8±16.2 [ohms] p<0.05). CONCLUSIONS: IL-13 drives features of airway remodeling in severe asthma which are partially reversed by inhibiting IL-4Rα receptor in vitro.

Discovery and Validation of a Volatile Signature of Eosinophilic Airway Inflammation in Asthma.

RATIONALE: Volatile organic compounds (VOCs) in asthmatic breath may be associated with sputum eosinophilia. We developed a volatile biomarker-signature to predict sputum eosinophilia in asthma. METHODS: VOCs emitted into the space above sputum samples (headspace) from severe asthmatics (n=36) were collected onto sorbent tubes and analysed using thermal desorption gas chromatography-mass spectrometry (TD-GC-MS). Elastic net regression identified stable VOCs associated with sputum eosinophilia ≥3% and generated a volatile biomarker signature. This VOC signature was validated in breath samples from: (I) acute asthmatics according to blood eosinophilia ≥0.3x109cells/L or sputum eosinophilia of ≥ 3% in the UK EMBER consortium (n=65) and U-BIOPRED-IMI consortium (n=42). Breath samples were collected onto sorbent tubes (EMBER) or Tedlar bags (U-BIOPRED) and analysed by gas-chromatography-mass spectrometry (GC×GC-MS -EMBER or GC-MS -U-BIOPRED). MAIN RESULTS: The in vitro headspace identified 19 VOCs associated with sputum eosinophilia and the derived VOC signature yielded good diagnostic accuracy for sputum eosinophilia ≥ 3% in headspace (AUROC (95% CI) 0.90(0.80-0.99), p<0.0001), correlated inversely with sputum eosinophil % (rs= -0.71, p<0.0001) and outperformed FeNO (AUROC (95% CI) 0.61(0.35-0.86). Analysis of exhaled breath in replication cohorts yielded a VOC signature AUROC (95% CI) for acute asthma exacerbations of 0.89(0.76-1.0) (EMBER cohort) with sputum eosinophilia and 0.90(0.75-1.0) in U-BIOPRED - again outperforming FeNO in U-BIOPRED 0.62 (0.33-0.90). CONCLUSIONS: We have discovered and provided early-stage clinical validation of a volatile biomarker signature associated with eosinophilic airway inflammation. Further work is needed to translate our discovery using point of care clinical sensors.

Downregulation of otulin induces inflammasome activation in neutrophilic asthma.

BACKGROUND: Neutrophilic asthma (NA) is a severe asthma phenotype associated with steroid resistance and IL-1ß overproduction; however, the exact mechanism remains unclear. Moreover, the dysfunction of TNF-α signaling pathway, a regulator of IL-1ß production, was associated with the deficiency of ovarian tumor protease deubiquitinase with linear linkage specificity (otulin) in autoimmune patients. OBJECTIVE: We hypothesized that otulin downregulation in macrophages (Mφ) could trigger Mφ activation via the nucleotide-binding domain, leucine-rich repeat, and pyrin domain-containing protein 3 (NLRP3) inflammasome signaling pathway. METHODS: We assessed the expressions of otulin in blood monocyte subsets from NA patients and in alveolar Mφ from NA mice. Additionally, we evaluated the functional consequences of otulin deficiency in bone marrow-derived Mφ. The effects of inhibiting receptor-interacting protein kinase (RIPK)-1 and RIPK-3 on neutrophils and group 3 innate lymphoid cells (ILC3s) were assessed in vitro and in vivo. RESULTS: When comparing nonclassical monocytes, a significant downregulation of otulin in the intracellular components was observed in NA patients compared to healthy controls (P = .005). Moreover, isolated alveolar Mφ from the NA mice exhibited lower otulin expression compared to those from control mice. After otulin knockdown in bone marrow-derived Mφ, we observed spontaneous IL-1ß production depending on NLRP3 inflammasome. Moreover, the infiltrated neutrophils and ILC3s were significantly decreased by combined treatment of RIPK-1 and RIPK-3 inhibitors through blocking IL-1ß release in NA. CONCLUSIONS: IL-1ß overproduction caused by a deficiency of otulin, an upstream triggering factor, could be a promising diagnostic and therapeutic target for NA.

Anti-IL-4R versus Anti-IL-5/5R after Anti-IL-5/5R failure in asthma: an emulated target trial.

BACKGROUND: Switching biologics is now common practice in severe eosinophilic asthma. After insufficient response to anti-interleukin 5 or 5 receptor (anti-IL-5/5R), the optimal switch between an anti-IL-4R monoclonal antibody (mAb) (inter-class) or another anti-IL-5/5R drug (intra-class) remains unknown. OBJECTIVE: We compared the effectiveness of these two strategies on asthma control in patients with severe eosinophilic asthma and insufficient response to an anti-IL-5/5R mAb. METHODS: We emulated a target randomized trial using observational data from the RAMSES Cohort. Eligible patients were switched to an anti-IL-4R mAb or another anti-IL-5/5R drug after insufficient response to an anti-IL-5/5R mAb. The primary outcome was the change in Asthma Control Test (ACT) score at 6 months. RESULTS: Among the 2046 patients in the cohort, 151 were included in the study: 103 switched to an anti-IL-4R mAb and 48 to another anti-IL-5/5R. At 6 months, the difference in ACT score improvement was not statistically significant (mean difference groups, 0.82 [-0.47,2.10], p=0.213). The inter-class group exhibited greater cumulative reduction in oral corticosteroids dose (Pinter-intra -1.05g [-1.76, -0.34], p=0.041). The inter-class group had a better effect, although not significantly, on reducing exacerbations (Δinter-intra -0.37 [-0.77, 0.02], p=0.124) and increasing lung function (FEV1) (126.8 ml [-12.7, 266.4], p=0.124). CONCLUSION: After anti-IL-5/5R mAb insufficient response, switching to dupilumab demonstrated similar improvement in ACT scores compared to intra-class switching. However, it appeared more effective in reducing oral corticosteroid use. Larger studies are warranted to confirm these results.

Airway wall extracellular matrix changes induced by bronchial thermoplasty in severe asthma.

BACKGROUND: Airway remodeling is a prominent feature of asthma, which involves increased airway smooth muscle mass and altered extracellular matrix composition. Bronchial thermoplasty (BT), a bronchoscopic treatment for severe asthma, targets airway remodeling. OBJECTIVE: We sought to investigate the effect of BT on extracellular matrix composition and its association with clinical outcomes. METHODS: This is a substudy of the TASMA trial. Thirty patients with severe asthma were BT-treated, of whom 13 patients were treated for 6 months with standard therapy (control group) before BT. Demographic data, clinical data including pulmonary function, and bronchial biopsies were collected. Biopsies at BT-treated and nontreated locations were analyzed by histological and immunohistochemical staining. Associations between histology and clinical outcomes were explored. RESULTS: Six months after treatment, it was found that the reticular basement membrane thickness was reduced from 7.28 µm to 5.74 µm (21% relative reduction) and the percentage area of tissue positive for collagen increased from 26.3% to 29.8% (13% relative increase). Collagen structure analysis revealed a reduction in the curvature frequency of fibers. The percentage area positive for fibulin-1 and fibronectin increased by 2.5% and 5.9%, respectively (relative increase of 124% and 15%). No changes were found for elastin. The changes in collagen and fibulin-1 negatively associated with changes in FEV1 reversibility. CONCLUSIONS: Besides reduction of airway smooth muscle mass, BT has an impact on reticular basement membrane thickness and the extracellular matrix arrangement characterized by an increase in tissue area occupied by collagen with a less dense fiber organization. Both collagen and fibulin-1 are negatively associated with the change in FEV1 reversibility.

A novel syndrome of silent rhinovirus-associated bronchoalveolitis in children with recurrent wheeze.

BACKGROUND: Rhinovirus (RV) infections trigger wheeze episodes in children. Thus, understanding of the lung inflammatory response to RV in children with wheeze is important. OBJECTIVES: This study sought to examine the associations of RV on bronchoalveolar lavage (BAL) granulocyte patterns and biomarkers of inflammation with age in children with treatment-refractory, recurrent wheeze (n = 616). METHODS: Children underwent BAL to examine viral nucleic acid sequences, bacterial cultures, granulocyte counts, and phlebotomy for both general and type-2 inflammatory markers. RESULTS: Despite the absence of cold symptoms, RV was the most common pathogen detected (30%), and when present, was accompanied by BAL granulocytosis in 75% of children. Compared to children with no BAL pathogens (n = 341), those with RV alone (n = 127) had greater (P < .05) isolated neutrophilia (43% vs 16%), mixed eosinophils and neutrophils (26% vs 11%), and less pauci-granulocytic (27% vs 61%) BAL. Children with RV alone furthermore had biomarkers of active infection with higher total blood neutrophils and serum C-reactive protein, but no differences in blood eosinophils or total IgE. With advancing age, the log odds of BAL RV alone were lower, 0.82 (5th-95th percentile CI: 0.76-0.88; P < .001), but higher, 1.58 (5th-95th percentile CI: 1.01-2.51; P = .04), with high-dose daily corticosteroid treatment. CONCLUSIONS: Children with severe recurrent wheeze often (22%) have a silent syndrome of lung RV infection with granulocytic bronchoalveolitis and elevated systemic markers of inflammation. The syndrome is less prevalent by school age and is not informed by markers of type-2 inflammation. The investigators speculate that dysregulated mucosal innate antiviral immunity is a responsible mechanism.

Investigation of lactotransferrin messenger RNA expression levels as an anti-type 2 asthma biomarker.

BACKGROUND: Lactotransferrin (LTF) has an immunomodulatory function, and its expression levels are associated with asthma susceptibility. OBJECTIVES: We sought to investigate LTF messenger RNA (mRNA) expression levels in human bronchial epithelial cells (BECs) as an anti-type 2 (T2) asthma biomarker. METHODS: Association analyses between LTF mRNA expression levels in BECs and asthma-related phenotypes were performed in the Severe Asthma Research Program (SARP) cross-sectional (n = 155) and longitudinal (n = 156) cohorts using a generalized linear model. Correlation analyses of mRNA expression levels between LTF and all other genes were performed by Spearman correlation. RESULTS: Low LTF mRNA expression levels were associated with asthma susceptibility and severity (P < .025), retrospective and prospective asthma exacerbations, and low lung function (P < 8.3 × 10-3). Low LTF mRNA expression levels were associated with high airway T2 inflammation biomarkers (sputum eosinophils and fractional exhaled nitric oxide; P < 8.3 × 10-3) but were not associated with blood eosinophils or total serum IgE. LTF mRNA expression levels were negatively correlated with expression levels of TH2 or asthma-associated genes (POSTN, NOS2, and MUC5AC) and eosinophil-related genes (IL1RL1, CCL26, and IKZF2) and positively correlated with expression levels of TH1 and inflammation genes (IL12A, MUC5B, and CC16) and TH17-driven cytokines or chemokines for neutrophils (CXCL1, CXCL6, and CSF3) (P < 3.5 × 10-6). CONCLUSIONS: Low LTF mRNA expression levels in BECs are associated with asthma susceptibility, severity, and exacerbations through upregulation of airway T2 inflammation. LTF is a potential anti-T2 biomarker, and its expression levels may help determine the balance of eosinophilic and neutrophilic asthma.

Protein-Protein interactive networks identified in bronchoalveolar lavage of severe compared to nonsevere asthma.

INTRODUCTION: Previous bronchoalveolar lavage fluid (BALF) proteomic analysis has evaluated limited numbers of subjects for only a few proteins of interest, which may differ between asthma and normal controls. Our objective was to examine a more comprehensive inflammatory biomarker panel in quantitative proteomic analysis for a large asthma cohort to identify molecular phenotypes distinguishing severe from nonsevere asthma. METHODS: Bronchoalveolar lavage fluid from 48 severe and 77 nonsevere adult asthma subjects were assessed for 75 inflammatory proteins, normalized to BALF total protein concentration. Validation of BALF differences was sought through equivalent protein analysis of autologous sputum. Subjects' data, stratified by asthma severity, were analysed by standard statistical tests, principal component analysis and 5 machine learning algorithms. RESULTS: The severe group had lower lung function and greater health care utilization. Significantly increased BALF proteins for severe asthma compared to nonsevere asthma were fibroblast growth factor 2 (FGF2), TGFα, IL1Ra, IL2, IL4, CCL8, CCL13 and CXCL7 and significantly decreased were platelet-derived growth factor a-a dimer (PDGFaa), vascular endothelial growth factor (VEGF), interleukin 5 (IL5), CCL17, CCL22, CXCL9 and CXCL10. Four protein differences were replicated in sputum. FGF2, PDGFaa and CXCL7 were independently identified by 5 machine learning algorithms as the most important variables for discriminating severe and nonsevere asthma. Increased and decreased proteins identified for the severe cluster showed significant protein-protein interactions for chemokine and cytokine signalling, growth factor activity, and eosinophil and neutrophil chemotaxis differing between subjects with severe and nonsevere asthma. CONCLUSION: These inflammatory protein results confirm altered airway remodelling and cytokine/chemokine activity recruiting leukocytes into the airways of severe compared to nonsevere asthma as important processes even in stable status.

Immunoglobulin free light chains in severe asthma patient: Could they be a new biomarker?

BACKGROUND: Increasing evidence is available about the presence of increased serum concentration of immunoglobulin (Ig) free light chains (FLCs) in both atopic and non-atopic inflammatory diseases, including severe asthma, providing a possible new biomarker of disease. METHODS: We analyzed clinical and laboratory data, including FLCs, obtained from a cohort of 79 asthmatic subjects, clinically classified into different GINA steps. A control group of 40 age-matched healthy donors (HD) was considered. Particularly, HD have been selected according to the absence of monoclonal components (in order to exclude paraproteinemias), were tested for total IgE (that were in the normal ranges) and were negative for aeroallergens specific IgE. Moreover, no abnormality of common inflammatory markers (i.e., erythrocyte sedimentation rate and C-reactive protein) was detectable. RESULTS: FLC-k levels were significantly increased in the asthmatic population, compared to the control group. Despite the absence of statistically significant differences in FLC-λ levels, the FLC-k/FLC-λ ratio displayed remarkable differences between the two groups. A positive correlation between FLC-κ and FLC-λ levels was found. FLC- λ level displayed a significant negative correlation with the FEV1 value. Moreover, the FLC-κ /FLC- λ ratio was negatively correlated with the SNOT-22 score and a positive correlation was observed between FLCs and Staphylococcus Aureus IgE enterotoxins sensitization. CONCLUSIONS: Our findings confirmed the role of FLCs in asthma as a potential biomarker in an inflammatory disease characterized by different endotypes and phenotypes. In particular, FLC-κ and FLC-k/FLC-λ ratio could be a qualitative indicator for asthma, while FLC-λ levels could be a quantitative indicator for clinical severity parameters.

Real-world biologics response and super-response in the International Severe Asthma Registry cohort.

BACKGROUND: Biologic asthma therapies reduce exacerbations and long-term oral corticosteroids (LTOCS) use in randomized controlled trials (RCTs); however, there are limited data on outcomes among patients ineligible for RCTs. Hence, we investigated responsiveness to biologics in a real-world population of adults with severe asthma. METHODS: Adults in the International Severe Asthma Registry (ISAR) with ≥24 weeks of follow-up were grouped into those who did, or did not, initiate biologics (anti-IgE, anti-IL5/IL5R, anti-IL4/13). Treatment responses were examined across four domains: forced expiratory volume in 1 second (FEV1) increase by ≥100 mL, improved asthma control, annualized exacerbation rate (AER) reduction ≥50%, and any LTOCS dose reduction. Super-response criteria were: FEV1 increase by ≥500 mL, new well-controlled asthma, no exacerbations, and LTOCS cessation or tapering to ≤5 mg/day. RESULTS: 5.3% of ISAR patients met basic RCT inclusion criteria; 2116/8451 started biologics. Biologic initiators had worse baseline impairment than non-initiators, despite having similar biomarker levels. Half or more of initiators had treatment responses: 59% AER reduction, 54% FEV1 increase, 49% improved control, 49% reduced LTOCS, of which 32%, 19%, 30%, and 39%, respectively, were super-responses. Responses/super-responses were more frequent in biologic initiators than in non-initiators; nevertheless, ~40-50% of initiators did not meet response criteria. CONCLUSIONS: Most patients with severe asthma are ineligible for RCTs of biologic therapies. Biologics are initiated in patients who have worse baseline impairments than non-initiators despite similar biomarker levels. Although biologic initiators exhibited clinical responses and super-responses in all outcome domains, 40-50% did not meet the response criteria.

Exploring the Autoimmune Pathogenesis in Severe Asthma.

INTRODUCTION: Severe asthma has a poor response to hormone therapy and a poor level of control, so the discovery of new pathogenetic mechanisms is important for diagnosing and treating severe asthma. IL-35 may play a protective role in autoimmune diseases by directly or indirectly inhibiting the secretion of IL-17, which is an important proinflammatory factor involved in the occurrence and development of autoimmune diseases. The autologous serum skin test (ASST) is a good sensitivity and specificity screening test for autoimmune functional autoantibodies. We compared the levels of IL-35 and IL-17 in serum samples, the positive rate of ASST, the level of exhaled nitric oxide (FeNO), and the atopic constitution in patients with severe asthma to those with mild-to-moderate asthma so as to explore the possible autoimmune pathogenesis of severe asthma. METHODS: Patients with mild-to-moderate and severe asthma were enrolled. Their age, gender, smoking history, family history of asthma, history of allergic rhinitis, positive allergen results, serum total IgE (TlgE), allergen-specific IgE (slgE), routine blood, ASST results, and FeNO test results were compared and analyzed. The IL-35 and IL-17 levels in serum samples from both groups were measured by enzyme-linked immunosorbent assay for comparison and analysis. The SPSS 22.0 software package was used for statistical analysis. RESULTS: A total of 50 patients with mild-to-moderate asthma and 31 patients with severe asthma were included in this study. The proportion of patients with a history of smoking and a family history of asthma was significantly higher in the severe asthma group compared to the mild-to-moderate asthma group (all p < 0.05); the number of positive allergen tests was significantly lower in patients with severe asthma compared to those with mild-to-moderate asthma (p < 0.001). The rate of positive ASST was significantly higher in patients with severe asthma than in patients with mild-to-moderate asthma (p < 0.05). Serum IL-17 levels were significantly higher in patients with severe asthma than in patients with mild-to-moderate asthma (p < 0.05), but serum IL-35 level between the two group was not significantly different (p = 0.113). ASST-positive patients had a statistically significant increase in the risk of developing severe asthma, while patients with allergen positive were less likely to develop severe asthma (positive ASST: OR = 5.277, p = 0.024; allergen positivity: OR = 0.123, p = 0.001). CONCLUSIONS: IL-35 has a weaker inhibitory effect on high IL-17 expression in patients with severe asthma, and the rate of positive ASST was significantly higher in patients with severe asthma, which all suggested the possibility of autoimmune pathogenesis in patients with severe asthma.

Prediction of Clinical Response to Dupilumab in Patients with Severe Asthma Using Fractional Exhaled Nitric Oxide Combined with Pulmonary Function Testing.

INTRODUCTION: This study aimed to assess the effectiveness of fractional exhaled nitric oxide (FeNO) combined with pulmonary function testing (PFT) for predicting the treatment outcome of patients with severe asthma receiving dupilumab. METHODS: A total of 31 patients with severe asthma visiting our hospital from January 2022 to June 2023 were included in this study, with 28 patients completing a 16-week course of dupilumab treatment. Baseline clinical data, including demographic information, blood eosinophil counts, serum IgE levels, FeNO, asthma control test (ACT), asthma control questionnaire (ACQ), and other parameters, were collected. A predictive model using a generalized linear model was established. RESULTS: Following the 16-week course of dupilumab treatment, 22 patients showed effective response based on GETE scores, while 6 patients were nonresponders. Notably, significant improvements were observed in clinical parameters such as blood eosinophil counts, serum IgE levels, FeNO, FEV1, FEV1%, ACT, and ACQ in both response groups (p < 0.05). FeNO and pulmonary function tests demonstrated AUC values of 0.530, 0.561, and 0.765, respectively, in predicting the clinical efficacy of dupilumab, which were lower than when FeNO was combined with FEV1%. The combination of FeNO and FEV1% had a sensitivity of 1.000 and specificity of 0.591 in predicting treatment response. CONCLUSION: The combined assessment of FeNO and FEV1% provides improved accuracy for predicting the clinical efficacy of dupilumab in managing severe asthma. However, further larger scale clinical studies with comprehensive follow-up data are needed to validate the therapeutic efficacy and applicability across diverse patient populations.

Neutrophilia in severe asthma is reduced in Ormdl3 overexpressing mice.

Genome-wide association studies have linked the ORM (yeast)-like protein isoform 3 (ORMDL3) to asthma severity. Although ORMDL3 is a member of a family that negatively regulates serine palmitoyltransferase (SPT) and thus biosynthesis of sphingolipids, it is still unclear whether ORMDL3 and altered sphingolipid synthesis are causally related to non-Th2 severe asthma associated with a predominant neutrophil inflammation and high interleukin-17 (IL-17) levels. Here, we examined the effects of ORMDL3 overexpression in a preclinical mouse model of allergic lung inflammation that is predominantly neutrophilic and recapitulates many of the clinical features of severe human asthma. ORMDL3 overexpression reduced lung and circulating levels of dihydrosphingosine, the product of SPT. However, the most prominent effect on sphingolipid levels was reduction of circulating S1P. The LPS/OVA challenge increased markers of Th17 inflammation with a predominant infiltration of neutrophils into the lung. A significant decrease of neutrophil infiltration was observed in the Ormdl3 transgenic mice challenged with LPS/OVA compared to the wild type and concomitant decrease in IL-17, that plays a key role in the pathogenesis of neutrophilic asthma. LPS decreased survival of murine neutrophils, which was prevented by co-treatment with S1P. Moreover, S1P potentiated LPS-induced chemotaxis of neutrophil, suggesting that S1P can regulate neutrophil survival and recruitment following LPS airway inflammation. Our findings reveal a novel connection between ORMDL3 overexpression, circulating levels of S1P, IL-17 and neutrophil recruitment into the lung, and questions the potential involvement of ORMDL3 in the pathology, leading to development of severe neutrophilic asthma.

Blockade of MIF biological activity ameliorates house dust mite-induced allergic airway inflammation in humanized MIF mice.

Macrophage migration inhibitory factor (MIF) expression is controlled by a functional promoter polymorphism, where the number of tetranucleotide repeats (CATTn ) corresponds to the level of MIF expression. To examine the role of this polymorphism in a pre-clinical model of allergic asthma, novel humanized MIF mice with increasing CATT repeats (CATT5 and CATT7 ) were used to generate a physiologically relevant scale of airway inflammation following house dust mite (HDM) challenge. CATT7 mice expressing high levels of human MIF developed an aggressive asthma phenotype following HDM challenge with significantly elevated levels of immune cell infiltration, production of inflammatory mediators, goblet cell hyperplasia, subepithelial collagen deposition, and airway resistance compared to wild-type controls. Importantly the potent MIF inhibitor SCD-19 significantly mitigated the pathophysiology observed in CATT7 mice after HDM challenge, demonstrating the fundamental role of endogenous human MIF expression in the severity of airway inflammation in vivo. Up to now, there are limited reproducible in vivo models of asthma airway remodeling. Current asthma medications are focused on reducing the acute inflammatory response but have limited effects on airway remodeling. Here, we present a reproducible pre-clinical model that capitulates asthma airway remodeling and suggests that in addition to having pro-inflammatory effects MIF may play a role in driving airway remodeling.

COBRAPed cohort: Do sensitization patterns differentiate children with severe asthma from those with a milder disease?

BACKGROUND: It is unclear whether sensitization patterns differentiate children with severe recurrent wheeze (SRW)/severe asthma (SA) from those with non-severe recurrent wheeze (NSRW)/non-severe asthma (NSA). Our objective was to determine whether sensitization patterns can discriminate between children from the French COBRAPed cohort with NSRW/NSA and those with SRW/SA. METHODS: IgE to 112 components (c-sIgE) (ImmunoCAP® ISAC) were analyzed in 125 preschools (3-6 years) and 170 school-age children (7-12 years). Supervised analyses and clustering methods were applied to identify patterns of sensitization among children with positive c-sIgE. RESULTS: We observed c-sIgE sensitization in 51% of preschool and 75% of school-age children. Sensitization to house dust mite (HDM) components was more frequent among NSRW than SRW (53% vs. 24%, p < .01). Sensitization to non-specific lipid transfer protein (nsLTP) components was more frequent among SA than NSA (16% vs. 4%, p < .01) and associated with an FEV1/FVC < -1.64 z-score. Among sensitized children, seven clusters with varying patterns were identified. The two broader clusters identified in each age group were characterized by "few sensitizations, mainly to HDM." One cluster (n = 4) with "multiple sensitizations, mainly to grass pollen, HDM, PR-10, and nsLTP" was associated with SA in school-age children. CONCLUSIONS: Although children with wheeze/asthma display frequent occurrences and high levels of sensitization, sensitization patterns did not provide strong signals to discriminate children with severe disease from those with milder disease. These results suggest that the severity of wheeze/asthma may depend on both IgE- and non-IgE-mediated mechanisms.

Aerobic physical training reduces severe asthma phenotype involving kinins pathway.

INTRODUCTION: Aerobic physical training (APT) reduces eosinophilic airway inflammation, but its effects and mechanisms in severe asthma remain unknown. METHODS: An in vitro study employing key cells involved in the pathogenesis of severe asthma, such as freshly isolated human eosinophils, neutrophils, and bronchial epithelial cell lineage (BEAS-2B) and lung fibroblasts (MRC-5 cells), was conducted. Additionally, an in vivo study using male C57Bl/6 mice, including Control (Co; n = 10), Trained (Exe; n = 10), house dust mite (HDM; n = 10), and HDM + Trained (HDM + Exe; n = 10) groups, was carried out, with APT performed at moderate intensity, 5x/week, for 4 weeks. RESULTS: HDM and bradykinin, either alone or in combination, induced hyperactivation in human neutrophils, eosinophils, BEAS-2B, and MRC-5 cells. In contrast, IL-10, the primary anti-inflammatory molecule released during APT, inhibited these inflammatory effects, as evidenced by the suppression of numerous cytokines and reduced mRNA expression of the B1 receptor and ACE-2. The in vivo study demonstrated that APT decreased bronchoalveolar lavage levels of bradykinin, IL-1ß, IL-4, IL-5, IL-17, IL-33, TNF-α, and IL-13, while increasing levels of IL-10, klotho, and IL-1RA. APT reduced the accumulation of polymorphonuclear cells, lymphocytes, and macrophages in the peribronchial space, as well as collagen fiber accumulation, epithelial thickness, and mucus accumulation. Furthermore, APT lowered the expression of the B1 receptor and ACE-2 in lung tissue and reduced bradykinin levels in the lung tissue homogenate compared to the HDM group. It also improved airway resistance, tissue resistance, and tissue damping. On a systemic level, APT reduced total leukocytes, eosinophils, neutrophils, basophils, lymphocytes, and monocytes in the blood, as well as plasma levels of IL-1ß, IL-4, IL-5, IL-17, TNF-α, and IL-33, while elevating the levels of IL-10 and IL-1RA. CONCLUSION: These findings indicate that APT inhibits the severe asthma phenotype by targeting kinin signaling.

Clinical remission maintained and improved over time in patients with severe asthma treated with omalizumab.

BACKGROUND: Clinical remission has recently been proposed as a possible treatment goal even in severe asthma. In this real-world study, we aimed to assess the achievement rate and predictive factors of clinical remission using omalizumab in patients with severe asthma. METHODS: This retrospective observational study included patients with severe asthma initiated with omalizumab therapy and recruited from the asthma clinic of the Akdeniz University Hospital, Turkey. Clinical remission was defined as patients who received no oral corticosteroid (OCS) therapy; showed no exacerbations; showed an asthma control questionnaire score of ≤ 1, asthma control test (ACT) of ≥ 20, or both and, FEV1 of ≥ 80% predicted. RESULTS: A total of 58 patients were included in the study, with an average age of 56.4 ± 13.6 years. The mean duration of asthma was 23.5 ± 11.8 years and the mean duration of omalizumab treatment was 80.05 ± 35.04 months. Clinical remission rates were 25.9% in the first and second year, 34.0% in the third year, 34.1% in the fourth year and 47.4% in the fifth year. Pre-omalizumab ACT, FEV1 (%) and OCS use were significantly higher in patients with clinical remission at 1 year. Logistic regression analyses showed that none of the factors predicted clinical remission. CONCLUSION: Omalizumab has the potential to induce disease remission in a significant proportion of people with severe asthma, and this is maintained and improved over time.

Digitally monitored inhaled therapy: a 'smart' way to manage severe asthma?

INTRODUCTION: One of the fundamental challenges of managing patients with severe asthma is treatment adherence, particularly with inhaled corticosteroids. Adherence is difficult to measure objectively and poor adherence is associated with worse outcomes. In this study, assess the ability of a 'smart' inhaler to record adherence in severe asthma patients and measure the impact of this on asthma control. METHODS: Consecutive consenting patients meeting criteria for biologics had their existing high-dose ICS/LABA//LAMA combination inhaler/s switched to mometasone/indacaterol/glycopyrronium (114/46/136). Routine clinical data, including blood eosinophils, FeNO, and ACQ-6 scores were collected at baseline and at 4 wk. Adherence was then checked on the Propeller Health app, and good adherence was defined as >80% of prescribed usage. Participants were then followed-up at 12 months to record the proportion of patients who were initiated on biologics. RESULTS: 77 patients (mean [SD] age = 50.4 [15.7] years, 67.5% female [n = 52]) participated. 71 participants were able to use the device and 65% (n = 46) of these attained good asthma control and were not initiated on biologics at 12-month follow-up. Both groups demonstrated a significant reduction in ACQ6 score at follow-up (2.81 vs. 1.92, p < 0.001 and 3.05 vs. 2.60, p < 0.001, respectively), but there was no statistically significant difference in improvement between groups. Patients with optimal adherence also demonstrated a significant reduction in median FeNO at follow-up (47 ppb vs. 40 ppb, p = 0.003). CONCLUSIONS: In severe asthma patients, 'smart' inhalers may represent an effective management tool to improve adherence and asthma control, therefore avoiding the need for patients to commence biological therapies.

Efficacy of mepolizumab and omalizumab combination therapy in uncontrolled asthma.

OBJECTIVE: Results of biological therapies are often encouraging for severe asthma who are phenotyped as Type 2 inflammation. Unfortunately, some patients do not achieve the desired responses. In this group of patients, there are often switches between anti Ig E and anti-IL-5s and partial improvements are often is deemed sufficient. METHOD: We planned to start combination therapy with mepolizumab and omalizumab in a 52-year-old patient with uncontrolled allergic asthma whose asthma could not be controlled with omalizumab and mepolizumab treatment, respectively. After complete asthma control was achieved, we aimed to discontinue mepolizumab and continue with omalizumab because it was allergic asthma. RESULT: The combination of omalizumab 300 mg/month and mepolizumab 100 mg/month was tried and emergency admissions and oral corticosteroids were stopped. At the same time, significant improvement was observed in asthma control test, pulmonary function test and comfort of life. CONCLUSION: Combined use of Anti-Ig E (omalizumab) and Anti IL 5 (mepolizumab) with a synergistic effect by acting through both pathways, especially in patients with allergic asthma and high levels of both total Ig E and eosinophilia, was found to be effective and no side effects were observed in long-term follow-up. Combination therapy with omalizumab and mepolizumab may become a safe option in patients with severe allergic asthma with a Type 2 inflammatory phenotype who cannot be controlled with each biologic agent.

Dual biologics therapy in a patient with severe asthma and chronic urticaria: a case report and review of the literature.

INTRODUCTION: The data on the use of dual biologics are scant, but a topic of current interest. CASE STUDY: In this report, the treatment regimen of a patient with two T helper 2 pathway-related comorbidities, severe asthma, and chronic spontaneous urticaria, was presented. RESULTS: Both urticaria and asthma symptoms of the patient could not be controlled entirely with monotherapy while both diseases could be controlled after omalizumab-mepolizumab dual treatment. No adverse events were observed after 6 months of dual biologics use. CONCLUSION: This report supports other publications in the literature involving the use of dual biologics and provides a summary of the literature.