ACE2, TMPRSS2 AND FURIN GENE EXPRESSION IN THE AIRWAYS OF PEOPLE WITH ASTHMA - IMPLICATIONS FOR COVID-19.

To-date, there has not been a clear signal suggesting that asthma or treatment with inhaled steroids are a risk factor for severe COVID-19 disease. We have therefore explored ACE2 receptor mRNA expression, and co-factors for Sars-CoV-2 infectivity (TMPRSS2 and furin) in bronchial brushes and biopsies from people with asthma and healthy controls, and looked for relationships between asthma severity, Th2- and IL-17 dependent gene signatures, and clinical demographics (age, sex). We have looked at a cohort of 356 research participants from previously described studies. The only significant association was a positive correlation between ACE2 and IL-17-dependent gene expression, and an inverse correlation between ACE2 and Th2-cytokine-dependent gene expression. These data suggest that differences in ACE2, TMPRSS2 and furin epithelial and airway gene expression are unlikely to confer enhanced COVID-19 pneumonia risk in patients with asthma across all treatment intensities and severity

Fungal sensitization and its relationship to mepolizumab response in patients with severe eosinophilic asthma

Letter to the Editor: In asthma, sensitization to fungal, perennial or seasonal allergens increases the risk of uncontrolled symptoms, exacerbations and poor disease outcomes.1 In severe asthma, typically 20%-29% of patients show sensitization to ≥1 fungal allergen, with Aspergillus being one of the most common.2-4 These patients have worse lung function, increased risk of oral corticosteroid use, hospitalization and a greater degree of airflow obstruction than patients non-sensitized to fungal allergens. [opening paragraph

Airway Elastin is increased in severe asthma and relates to proximal wall area: histological and computed tomography findings from the U-BIOPRED severe asthma study

Background: Airway remodelling, which may include goblet cell hyperplasia / hypertrophy, changes in epithelial integrity, accumulation of extracellular matrix components, smooth muscle hypertrophy and thickening of the lamina reticularis, is a feature of severe asthma and contributes to the clinical phenotype. Objective: Within the U-BIOPRED severe asthma study, we have assessed histological elements of airway remodelling and their relationship to computed tomography (CT) measures of proximal airway dimensions. Methods: Bronchial biopsies were collected from two severe asthma groups, one non-smoker (SAn, n = 28) and one current/ex-smoker (SAs/ex, n = 13), and a mild-moderate asthma group (MMA, n = 28) classified and treated according to GINA guidelines, plus a healthy control group (HC, n = 33). Movat's pentachrome technique was used to identify mucin, elastin and total collagen in these biopsies. The number of goblet cells (mucin+) was counted as a percentage of the total number of epithelial cells and the percentage mucin epithelial area measured. The percentage area of elastic fibres and total collagen within the submucosa was also measured, and the morphology of the elastic fibres classified. Participants in the asthma groups also had a CT scan to assess large airway morphometry. Results: The submucosal tissue elastin percentage was higher in both severe asthma groups (16.1% SAn, 18.9% SAs/ex) compared with the HC (9.7%) but did not differ between asthma groups. There was a positive relationship between elastin and airway wall area measured by CT (n = 18–20, rho=0.544, p = 0.024), which also related to an increase in elastic fibres with a thickened lamellar morphological appearance. Mucin epithelial area and total collagen were not different between the four groups. Due to small numbers of suitable CT scans, it was not feasible to compare airway morphometry between the asthma groups. Conclusion: These findings identify a link between extent of elastin deposition and airway wall thickening in severe asthma

Airway remodelling rather than cellular infiltration characterizes both type2 cytokine biomarker‐high and ‐low severe asthma

BACKGROUND The most recognizable phenotype of severe asthma comprises people who are blood eosinophil and FeNO-high, driven by type-2 (T2) cytokine biology which responds to targeted biological therapies. However, in many people with severe asthma, these T2 biomarkers are suppressed but poorly controlled asthma persists. The mechanisms driving asthma in the absence of T2 biology are poorly understood. OBJECTIVES To explore airway pathology in T2 biomarker-high and -low severe asthma. METHODS T2 biomarker-high severe asthma (T2-high, n=17) was compared to biomarker-intermediate (T2-intermediate, n=21) and biomarker-low (T2-low, n=20) severe asthma, and healthy controls (n=28). Bronchoscopy samples were processed for immunohistochemistry, and sputum for cytokines, PGD and LTE measurements. RESULTS Tissue eosinophil, neutrophil and mast cell counts were similar across severe asthma phenotypes and not increased when compared to healthy controls. In contrast, the remodeling features of airway smooth muscle mass and MUC5AC expression were increased in all asthma groups compared to health, but similar across asthma subgroups. Submucosal glands were increased in T2-intermediate and T2-low asthma. In spite of similar tissue cellular inflammation, sputum IL-4, IL-5, and CCL26 were increased in T2-high versus T2-low asthma, and several further T2-associated cytokines, PGD and LTE , were increased in T2-high and T2-intermediate asthma compared to healthy controls. CONCLUSIONS Eosinophilic tissue inflammation within proximal airways is suppressed in T2 biomarker-high and T2-low severe asthma, but inflammatory and structural cell activation is present, with sputum T2-associated cytokines highest in T2 biomarker-high patients. Airway remodeling persists, and may be important for residual disease expression beyond eosinophilic exacerbations

Airway remodelling rather than cellular infiltration characterises both type2 cytokine biomarker-high and -low severe asthma

The most recognizable phenotype of severe asthma comprises people who are blood eosinophil and FeNO-high, driven by type-2 (T2) cytokine biology which responds to targeted biological therapies. However, in many people with severe asthma, these T2 biomarkers are suppressed but poorly controlled asthma persists. The mechanisms driving asthma in the absence of T2 biology are poorly understood. To explore airway pathology in T2 biomarker-high and -low severe asthma. T2 biomarker-high severe asthma (T2-high, n=17) was compared to biomarker-intermediate (T2-intermediate, n=21) and biomarker-low (T2-low, n=20) severe asthma, and healthy controls (n=28). Bronchoscopy samples were processed for immunohistochemistry, and sputum for cytokines, PGD2 and LTE4 measurements. Tissue eosinophil, neutrophil and mast cell counts were similar across severe asthma phenotypes and not increased when compared to healthy controls. In contrast, the remodeling features of airway smooth muscle mass and MUC5AC expression were increased in all asthma groups compared to health, but similar across asthma subgroups. Submucosal glands were increased in T2-intermediate and T2-low asthma. In spite of similar tissue cellular inflammation, sputum IL-4, IL-5, and CCL26 were increased in T2-high versus T2-low asthma, and several further T2-associated cytokines, PGD2 and LTE4 , were increased in T2-high and T2-intermediate asthma compared to healthy controls. Eosinophilic tissue inflammation within proximal airways is suppressed in T2 biomarker-high and T2-low severe asthma, but inflammatory and structural cell activation is present, with sputum T2-associated cytokines highest in T2 biomarker-high patients. Airway remodeling persists, and may be important for residual disease expression beyond eosinophilic exacerbations.</p

Factors affecting adherence with treatment advice in a clinical trial of patients with severe asthma.

Understanding why patients with severe asthma do not follow healthcare provider (HCP) advice to adjust treatment is critical to achieving personalised disease management.We reviewed patient choice to follow HCP advice to adjust asthma treatment in a randomised, controlled, single-blind (study participant), multi-centre, parallel group 48-week clinical study comparing biomarker directed treatment adjustment to standard care in severe asthma.Of 1572 treatment advisories (301 participants), instructions were followed in 1377 cases (87.6%). Patients were more likely to follow advice to remain on treatment (96.7%) than to either reduce (70.3%) or increase (67.1%) their treatment, with 64% of patients following all treatment advice. Multivariate analysis associated belonging to an ethnic minority group (OR: 3.10; 95% CI: 1.68, 5.73) and prior study medication changes (≥2 OR: 2.77, 95% CI: 1.51, 5.10) with failure to follow treatment advice. In contrast, emergency room attendance in the prior year (OR: 0.54, 95% CI: 0.32, 0.92) was associated with following treatment advice. The largest effect was seen with transition onto or off oral corticosteroids (OR: 29.28; 95% CI: 16.07, 53.36) when compared to those requested to maintain treatment. Centre was also an important determinant regarding the likelihood of patients to follow treatment advice.Belonging to an ethnic minority group and multiple prior treatment adjustments were associated with not following HCP treatment advice. Patients also responded differently to HCP advice across UK specialist centres. These findings have implications for generalisability for models of care in severe asthma and require further focussed studies. Conclusions</h4

Biomarker Predictors of Clinical Efficacy of the Anti-IgE Biologic, Omalizumab, in Severe Asthma in Adults: Results of the SoMOSA Study

The anti-IgE monoclonal, omalizumab, is widely used for severe asthma. This study aimed to identify biomarkers that predict clinical improvement during one year of omalizumab treatment.1-year, open-label, Study of Mechanisms of action of Omalizumab in Severe Asthma (SoMOSA) involving 216 severe (GINA step 4/5) uncontrolled atopic asthmatics (≥2 severe exacerbations in previous year) on high-dose inhaled corticosteroids, long-acting β-agonists, ± mOCS. It had two phases: 0-16 weeks, to assess early clinical improvement by Global Evaluation of Therapeutic Effectiveness (GETE), and 16-52 weeks, to assess late responses by ≥50% reduction in exacerbations or dose of maintenance oral corticosteroids (mOCS). All participants provided samples (exhaled breath, blood, sputum, urine) before and after 16 weeks of omalizumab treatment.191 patients completed phase 1; 63% had early improvement. Of 173 who completed phase 2, 69% had reduced exacerbations by ≥50%, while 57% (37/65) on mOCS reduced their dose by ≥50%. The primary outcome 2, 3-dinor-11-β-PGF2α, GETE and standard clinical biomarkers (blood and sputum eosinophils, exhaled nitric oxide, serum IgE) did not predict either clinical response. Five breathomics (GC-MS) and 5 plasma lipid biomarkers strongly predicted the ≥50% reduction in exacerbations (receiver operating characteristic area under the curve (AUC): 0.780 and 0.922, respectively) and early responses (AUC:0.835 and 0.949, respectively). In independent cohorts, the GC-MS biomarkers differentiated between severe and mild asthma. Conclusions This is the first discovery of omics biomarkers that predict improvement to a biologic for asthma. Their prospective validation and development for clinical use is justified. Background Methods Results</p