Severe Asthma Group Research Articles

Fatigue in severe pediatric asthma patients: Results of the PANDA study.

Fatigue is a commonly reported clinical symptom, yet research on fatigue in children with severe asthma is missing. We aimed to explore the extent of fatigue in severe pediatric asthma and identify associated factors. This study was conducted within the Pediatric Asthma Non-Invasive Diagnostic Approaches (PANDA), an observational cohort of 6- to 17-year-old Dutch children with severe asthma. The Pediatric Quality of Life Inventory Multidimensional Fatigue Scale (PedsQL™-MFS) was used to measure self-reported fatigue. Fatigue levels were compared with a general pediatric Dutch population using linear regression, and quantifying the prevalence of "fatigued" (-2 < Standard deviations [SD] ≤ -1) and "severely fatigued" (SD ≤ -2) children. Secondly, we performed linear regression analyses to explore whether fatigue levels were independently associated with asthma attacks, comorbidities, medication, pulmonary function, symptom control, and asthma-related quality of life (QoL). Severe pediatric asthma patients (n = 78, mean age 11.8 ± 3.1 years) reported significantly more fatigue than Dutch peers (n = 328, mean age 11.8 ± 3.2 years) mean difference in z-score: -0.68; 95%CI -0.96, -0.40. In the severe asthma group, 28.2% scored as "fatigued" and 15.4% as "severely fatigued," compared with 14.0% and 3.4% in the general population. In pediatric asthma patients, asthma-related QoL (β = 0.77, p < .01, ΔR2 = .43), symptom control (β = 0.56, p < .01, ΔR2 = .24) and a dysfunctional breathing pattern (β = -0.36, p < .01, ΔR2 = .12) were most strongly associated with fatigue scores. Fatigue is a common symptom in children with severe asthma and is associated with multiple clinical factors and patient-reported outcomes. It should be considered as an important treatment target.

Effect of biologic therapies on quality of life in severe asthma: Findings from the PRISM study

BackgroundAnti-type 2 (T2) biologic therapies (biologics) improve exacerbation rates, lung function, and asthma-related quality of life (QoL) in patients with severe T2 asthma. However, studies comparing different biologics are lacking. We evaluated the QoL in patients with severe asthma comprehensively and compare the efficacy of different T2-directed biologics using QoL questionnaires. MethodsWe compared the QoL between severe and mild-to-moderate asthma and between severe asthma with and without biologics treatment. Data of mild-to-moderate were extracted from the Cohort for Reality and Evolution of Adult Asthma in Korea, and data of severe asthma were collected from the Precision Medicine Intervention in Severe Asthma. We included 183 patients with severe asthma treated with T2 biologics or conventional therapy between April 2020 and May 2021 and assessed QoL of them using the Questionnaire for Adult Korean Asthmatics (QLQAKA), Severe Asthma Questionnaire (SAQ), and EuroQoL-5Dimensions (EQ-5D) at baseline and 6 months. ResultsThe EQ-5D index (0.803) of severe asthma was lower than that of other chronic diseases representing a worse QoL. The scores for all questions of QLQAKA, except “cough,” were lower (less control) in the severe asthma group than in the mild-to-moderate asthma group at baseline and 6 months (P < 0.05). The total scores and subscores of all domains of the QLQAKA, SAQ, and EQ-5D improved significantly 6 months after biologic therapy but not after conventional therapy. The total QLQAKA, SAQ, and EQ-5D scores improved after 6 months in the anti-IL-5 (P < 0.05) and anti-IL-4/IL-13 (P < 0.05) treatment groups with no significant difference between groups (P > 0.05). ConclusionQoL was worse in severe asthma than in mild-to-moderate asthma and other chronic diseases. T2 biologics equally improved QoL in patients with severe asthma.

Comparison of the symptom networks of long-COVID and chronic fatigue syndrome: From modularity to connectionism.

The objective was to compare the symptom networks of long-COVID and chronic fatigue syndrome (CFS) in conjunction with other theoretically relevant diagnoses in order to provide insight into the etiology of medically unexplained symptoms (MUS). This was a cross-sectional comparison of questionnaire items between six groups identified by clinical diagnosis. All participants completed a 65-item psychological and somatic symptom questionnaire (GSQ065). Diagnostically labelled groups were long-COVID (N = 107), CFS (N = 254), irritable bowel syndrome (IBS, N = 369), fibromyalgia (N = 1,127), severe asthma (N = 100) and healthy group (N = 207). The 22 symptoms that best discriminated between the six groups were selected for network analysis. Connectivity, fragmentation and number of symptom clusters (statistically related symptoms) were assessed. Compared to long-COVID, the symptom networks of CFS, IBS and fibromyalgia had significantly lower connectivity, greater fragmentation and more symptom clusters. The number of clusters varied between 9 for CFS and 3 for severe asthma, and the content of clusters varied across all groups. Of the 33 symptom clusters identified over the six groups 30 clusters were unique. Although the symptom networks of long-COVID and CFS differ, the variation of cluster content across the six groups is inconsistent with a modular causal structure but consistent with a connectionist (network, parallel distributed processing) biological basis of MUS. A connectionist structure would explain why symptoms overlap and merge between different functional somatic syndromes, the failure to discover a biological diagnostic test and how psychological and behavioral interventions are therapeutic.

Understanding Breathlessness Burden and Psychophysiological Correlates in Asthma

BackgroundBreathlessness is a disabling symptom, with complexity that is often under recognised and under treated in asthma. ObjectiveTo highlight the burden of breathlessness in people with severe compared with mild-to-moderate asthma and identify psychophysiological correlates of breathlessness. MethodsThis was a cross-sectional study of people with mild-to-severe asthma, who attended two in-person visits to complete a multidimensional assessment. The proportion of people with mild-to-moderate versus severe asthma who reported physically limiting breathlessness (modified Medical Research Council [mMRC] dyspnoea score ≥2) was compared. Psychophysiological factors associated with breathlessness in people with asthma were identified via a directed acyclic graph and explored with multivariate logistic regression to predict breathlessness. Results144 participants were included, of which, 74 (51%) had mild-to-moderate asthma and 70 (49%) severe asthma. Participants were predominantly female (n=103, 72%) with a median (quartile 1, quartile 3) age of 63.4 (50.5,69.5) years and body mass index (BMI) of 31.3 (26.2, 36.0) kg/m2. The proportion of people reporting mMRC ≥2 was significantly higher in those with severe- (n=37, 53%) compared with mild-to-moderate (n=21, 31%) asthma (p=0.013). Dyspnoea-12 Total (8.00 [4.75, 17.00] versus 5.00 [2.00, 11.00], p=0.037) score was also significantly higher in the severe asthma group. Significant predictors of physically limiting breathlessness were: BMI, asthma control, exercise capacity, and hyperventilation symptoms. Airflow limitation and type-2 inflammation were poor breathlessness predictors. ConclusionOver half of people with severe asthma experience physically limiting breathlessness despite treatment. Targeting psychophysiological factors, or traits, associated with breathlessness may help relieve this distressing symptom, which is of high priority to people with asthma.

The role of 14-3-3β in acute asthma in children and analysis of the risk factors for asthma exacerbation

Objective To investigate the role of 14-3-3β in acute asthma exacerbations in children and analyze the risk factors for asthma exacerbations. Methods This study recruited 101 children with acute asthma exacerbations, 101 children with stable asthma, and 65 healthy children. Serum 14-3-3β was compared among the three groups. Factors such as asthma family history, skin prick test, serum-specific IgE test, coinfections, and clinical indicators (FeNO, FEV1, white blood cells, eosinophils, and serum IgE level) were compared between the asthma groups. Risk factors associated with acute asthma exacerbations were identified using multivariate logistic regression models. ROC curve was drawn to determine the diagnostic sensitivity and specificity of 14-3-3β. Results Serum 14-3-3β was significantly greater in the acute asthma group than in the stable asthma and control groups. Serum 14-3-3β was higher in severe acute asthma group than in mild-moderate asthma group. There were no significant differences in serum 14-3-3β levels between stable asthma and control groups (p > .05). Multivariate logistic regression analysis revealed that serum 14-3-3β level, FeNO, coinfection, and FEV1 z-score significantly increased the odds of acute asthma exacerbations in children. The optimal 14-3-3β cutoff value (39.79 ng/mL), had a sensitivity of 69.3% and specificity of 94.1% for predicting acute asthma exacerbations. Conclusions 14-3-3β is elevated in children with acute exacerbations of asthma, and increases with exacerbation severity. 14-3-3β, FeNO, FEV1, and coinfection could be independent risk factors for predicting asthma exacerbations. The optimal 14-3-3β cutoff value for predicting asthma exacerbations was 39.79 ng/mL.

Prevalence, T2 Biomarkers, and Cost of Severe Asthma in the Era of Biologics: The BRAVO-1 Study.

Background: The last decade has seen new classifications of the pathophysiology of asthma that have changed the treatment options available. Objectives: To update data on the prevalence of T2 asthma, comorbidities, biomarker characterization, and costs of severe asthma in patients aged ≥12 years, taking into account new classifications and treatment options. Retrospective, observational, nationwide study using a top-down approach. Data were obtained from BIG-PAC®, an electronic medical record database of 1.7 million patients in Spain. The study population comprised patients aged ≥12 years who had received medical care during the period 2016-2017 and been diagnosed with asthma at least 1 year prior to the index date. Patients were followed for 1 year. The prevalence of asthma was 5.5%. Asthma was severe in 3031 of these patients (7.7%), 81.2% of whom presented T2 asthma. Among patients with severe asthma, 64.1% had uncontrolled disease, 31.2% were oral corticosteroid-dependent (37% in the uncontrolled severe asthma group), and only 3.8% were receiving biologics. The most common T2 comorbidities were allergic rhinitis (66.1%), atopic dermatitis (29.1%), and chronic rhinosinusitis with nasal polyps (14.6%). Mortality rates in the total population and uncontrolled severe asthma groups were 4.2% and 5.5%, respectively. The total annual costs per patient with severe asthma were €5890 (uncontrolled) and €2841 (controlled). In the era of biologics, most severe asthma patients present T2 asthma. Despite the availability of new treatments, rates of oral corticosteroid-dependent patients with uncontrolled severe asthma remain high, although biologics continue to be underused. The costs of uncontrolled severe asthma are twice as high as those of controlled severe asthma.

Predictor of recurrent exacerbations in pediatric asthma

BACKGROUND Asthma imposes a heavy morbidity burden during childhood. Severe persistent asthma significantly increases patients’ risk of exacerbations, hospital admissions, and mortality and often substantially impairs their quality of life. This study aimed to identify high-risk patients for exacerbation recurrence using spirometric parameters. METHODS A prospective cohort study involving patients with asthma aged 6–15 years was conducted at the principal children’s hospital in Mekong Delta, Vietnam, from June 2020 to June 2022. Demographic, clinical, and lung function characteristics of the patients were collected. Spirometry measurement parameters were utilized as predictive factors for the short-term asthma exacerbation recurrence. RESULTS Among all patients (mean age of 9.5 years old), 10.4% experienced recurrent exacerbations. FEV1, FVC, FEV1/FVC, FEF25–75, FEF25–75/FVC, and PEF, gradually decreased with increasing exacerbation severity (p&lt;0.01). All patients showed a positive bronchodilator responsiveness (BDR), with a mean value of 16.85 (3.00)%, which was significantly different between the severe and non-severe asthma groups (20.53 [2.83] versus 16.00 [2.35], p&lt;0.001). After adjusting in multivariable logistic regression, a BDR ≥20% was identified as the sole independent factor associated with an increased risk of asthma exacerbation recurrence (aOR 6.95, 95% CI 1.08–44.75, p = 0.041). CONCLUSIONS A high BDR can serve as a predictor of acute asthma exacerbation recurrence.

Activated non-neuronal cholinergic system correlates with non-type 2 inflammation and exacerbations in severe asthma

BackgroundNon-neuronal cholinergic system (NNCS) contributes to various inflammatory airway diseases. However, the role of NNCS in severe asthma (SA) remains largely unexplored. ObjectiveTo explore airway NNCS in SA. MethodsIn this prospective cohort study based on the Australasian Severe Asthma Network in a real-world setting, patients with SA (n = 52) and non-SA (n = 104) underwent clinical assessment and sputum induction. The messenger RNA (mRNA) levels of NNCS components and proinflammatory cytokines in the sputum were detected using real-time quantitative polymerase chain reaction, and the concentrations of acetylcholine (Ach)-related metabolites were evaluated using liquid chromatography coupled with tandem mass spectrometry. Asthma exacerbations were prospectively investigated during the next 12 months. The association between NNCS and future asthma exacerbations was also analyzed. ResultsPatients with SA were less controlled and had worse airway obstruction, a lower bronchodilator response, higher doses of inhaled corticosteroids, and more add-on treatments. The sputum mRNA levels of NNCS components, such as muscarinic receptors M1R-M5R, OCT3, VACHT, and ACHE; proinflammatory cytokines; and Ach concentration in the SA group were significantly higher than those in the non-SA group. Furthermore, most NNCS components positively correlated with non-type (T) 2 inflammatory profiles, such as sputum neutrophils, IL8, and IL1B. In addition, the mRNA levels of sputum M2R, M3R, M4R, M5R, and VACHT were independently associated with an increased risk of moderate-to-severe asthma exacerbations. ConclusionThis study indicated that the NNCS was significantly activated in SA, leading to elevated Ach and was associated with clinical features, non-T2 inflammation, and future exacerbations of asthma, highlighting the potential role of the NNCS in the pathogenesis of SA. Clinical Trial RegistrationChiCTR-OOC-16009529 (http://www.chictr.org.cn).

Evaluation of Healthy Eating Index and Children's Diet Inflammatory Index according to asthma severity group

BackgroundDiet may contribute to better asthma control in children by impacting the immune and inflammatory pathophysiology. Therefore, this study aimed to investigate differences in nutrient intake, Children’s Dietary Inflammatory Index (C-DII), and dietary quality according to asthma severity.Materials and methodsAsthma severity, dietary inflammatory status, and diet quality were assessed in a sample of 202 children with asthma (55.6% males, aged 5–18 years) attending a pediatric allergy outpatient clinic. Asthma severity was evaluated according to the Global Initiative for Asthma criteria and categorized as mild, moderate, or severe. The Children’s Dietary Inflammatory Index (C-DII) and Healthy Eating Index (HEI-2010) were calculated based on information collected by the 24-h dietary recall method. Dietary quality was categorized as poor, moderate, or good diet according to HEI-2010.ResultsThe mean age of the participants was 9.6 ± 3.2 years. Children with severe asthma were younger on average (p < 0.05). Children with mild asthma had significantly higher fiber and iron intake than those with moderate asthma (p < 0.05). C-DII values did not differ significantly according to asthma severity (p > 0.05). Dietary quality was evaluated as moderate in 89.1% of the participants and also showed no difference based on asthma severity.ConclusionsThese findings suggest that inflammatory status and diet quality may not affect asthma severity in children, highlighting the influence of various genetic and environmental factors on the association between diet and asthma severity. More comprehensive and longitudinal studies are needed to investigate the mechanisms linking diet and asthma.

There is no association between serum endotoxin levels and inflammation in asthma

Backround Endotoxin, in lipopolysaccharide structure (LPS), is the main component of the outer membrane of gram negative bacteria. LPS levels were associated with inflammatory disease. Asthma is a chronic inflammatory disease involving many different cell types and cellular elements. The association between LPS serum levels and the asthma is not well known. The aim of this study was to investigate the association between the LPS serum levels and the severity of asthma, demographic data and laboratory parameters. Methodology The study included 67 patients aged >18 years with a diagnosis of asthma, and 15 healthy volunteers with no history of chronic disease as a control group. The Asthma Control Test (ACT), Respiratory Function Tests (RFTs), fractional exhaled nitric oxide (FeNO), and endotoxin levels were measured and compared between the groups. The endotoxin measurements were performed using the ELISA method. Results The mild-moderate asthma group included 33 patients and the severe asthma group, 34 patients. The endotoxin level was measured as 17.78 (range 3.59 to 304.55) EU/ml in the patient group and 15 (range 4.01 to 74.06) EU/ml in the control group with no statistically significant difference determined between the groups. In the subgroups, the endotoxin level was measured as 15.21 (range 3.69 to 304.55) EU/ml in the mild-moderate group and 14.46 (range 3.59 to 278.86) EU/ml in the severe asthma group with no statistically significant difference determined between the groups. Conclusion The results of this study showed no relationship between serum endotoxin level and asthma or asthma severity.

Ventilation Heterogeneity Is a Treatable Trait in Severe Asthma

BackgroundVentilation heterogeneity is a feature of asthma and indicates small airway disease. Nuclear imaging methods assess ventilation heterogeneity which can facilitate clinical diagnosis and further our understanding of disease aetiology. ObjectiveWe sought to assess ventilation heterogeneity in severe eosinophilic asthma using ventilation/perfusion single-photon emission computed tomography (V/P SPECT), and to assess its use as an objective test of the effect of biologic treatment for ventilation defects in severe eosinophilic asthma. MethodsAdults (≥18 years) with severe asthma were recruited to participate in a cross-sectional observational study. Participants underwent a clinical assessment and V/P SPECT/CT using Technegas as the ventilation agent. Measures were repeated for a nested before-after treatment study in people with severe eosinophilic asthma commencing biologics. ResultsA total of 62 participants with severe asthma were recruited. From this, 38 participants with severe eosinophilic asthma were included in the before-after study. Ventilation heterogeneity was associated with clinical variables such as lung function impairment and significantly improved after monoclonal antibody treatment in the severe asthma group. The changes in ventilation heterogeneity correlated with change in post bronchodilator FEV1%predicted (r=-0.503, p=0.001) and post bronchodilator FEV1/FVC (r=-0.415, p=0.01). ConclusionVentilation heterogeneity is clinically significant, measurable, and treatable, which establishes ventilation heterogeneity as a treatable trait in severe asthma.

Peripheral neutrophils and oxidative stress-associated molecules for predicting the severity of asthma: a cross-sectional study based on multidimensional assessment.

This study aims to explore the relationship between the severity of asthma and neutrophils and related oxidative stress-associated molecules in peripheral blood and induced sputum. A total of 67 subjects were included in this study, namely, 25 patients with severe asthma and 42 patients with non-severe asthma. Clinical data, induced sputum and peripheral blood were collected. Lung function and molecules related to oxidative stress in induced sputum and peripheral blood of asthma patients were detected. The relationship between neutrophils and asthma severity was analyzed. HDAC2 mRNA and protein expression levels and HDAC2 activity were also analyzed. Multivariate logistic regression was performed to select statistically significant variables. The absolute value of neutrophils and percentage of neutrophils were higher in the severe asthma patients. These two values were used to predict the severity of asthma by ROC analysis, with the best cutoff values being 4.55 × 109/L (sensitivity 83.3%, specificity 64.0%) and 55.15% (sensitivity 54.8%, specificity 88.0%). The ROS concentration of neutrophils in the induced sputum samples and the 8-iso-PGF2α concentration in the peripheral blood samples were higher in the severe asthma group (P = 0.012; P = 0.044), whereas there was reduced HDAC2 protein activity in PBMCs (P < 0.001). A logistic equation and a nomogram were created to give a precise prediction of disease severity. Oxidative stress is increased in severe asthma patients. Peripheral blood neutrophils and 8-iso-PGF2α can be used as biomarkers to predict the severity of asthma. A prediction model was created for evaluating asthma severity.

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.

Interleukin-4 (C590T) Gene Polymorphism in Association with Asthma Severity.

A significant link between T allele of the IL-4 (C590T) gene and developing asthma in some populations was reported. However, no study discussed the link between IL-4 (C590T) gene polymorphism and asthma severity groups (mild and severe). This study investigated the link between IL-4 gene variation and asthma severity. The study included 215 asthmatic patients, of which 102 had mild asthma, and 126 participants were healthy controls. A previously published polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was used to identify various IL-4 (C590T) gene polymorphism genotypes. The T allele frequency was higher in mild asthma (p=0.002) but not in severe asthma (p=0.12) compared to controls. In mild asthma, the CT genotype and (CT+TT versus CC) increased the likelihood of asthma threefold (p<0.001, 0.001). However, no significant association with severe asthma was found in either genetic model. Stratification analysis showed that the C allele and CC genotype increased the risk of severe asthma (p=0.01). The recessive genetic model indicated a decrease in the risk of severe asthma (OR=0.5, p=0.01) in the non-adjusted regression analysis. Adjusting for age, sex, and other risk factors revealed that the IL-4 gene polymorphism did not influence the risk of severe asthma (OR=0.92, p=0.80); however, being an elderly female with a history of childhood-onset disease and associated nasal polyp (NP) increased the likelihood of severe asthma, OR=1.08, 2.01, 2.36, 8.42; p<0.001, 0.05, 0.05, <0.001, respectively. The T allele and CT genotype in the co-dominant genetic model and the (CT+TT) genotype in the recessive model were found to have a higher likelihood of developing mild asthma but not severe asthma; severe asthma was found to be higher in elderly females with a history of childhood-onset disease and associated nasal polyps.

Tumor Necrosis Factor-α (-308G>A) Gene Polymorphism and Its Association with Asthma and Atopy Status.

Asthma is one of the most prevalent chronic lung diseases that afflict genetically predisposed individuals. Certain cytokine gene polymorphisms have been associated with asthma. Tumor necrosis factor-alpha (TNF-α) is a potent inflammatory cytokine that can modulate nonspecific inflammation to influence asthma. This study aimed to define the relationship between the TNF gene polymorphism at position -308 and asthma susceptibility, as well as atopic and non-atopic asthma. Using polymerase chain reaction with sequence-specific primers, we investigated genotype frequencies and alleles of a polymorphic gene coding for TNF-α in 86 pediatric patients with asthma and 470 healthy controls of the same race. Seventy-four patients underwent a skin prick test. The homozygous AA variant (-308, rs1800629) was the most common genotype among patients, accounting for 63.3% of all cases. In contrast, homozygous GG (-308) was significantly less prevalent in the patient group compared to the control group. TNF A (-308) allele frequency was 85.5% among asthma patients and 16.6% among healthy controls. The genotype and allele frequencies of TNF (-308 A>G, rs1800629) did not differ between atopic and non-atopic asthma. In conclusion, TNF (-308) AA and AG genotypes are associated with asthma susceptibility in Iranian children, although there was no significant difference in polymorphism between atopic and non-atopic asthma and no difference in asthma severity groups.

Biomarkers associated with severity classification of asthma identified by comprehensive bioinformatics analysis

Using an integrated bioinformatics approach to find novel biomarkers that can predict asthma severity. From June 2022 to December 2022, this clinical medical study was conducted and completed in the Department of Allergy, Zhongnan Hospital of Wuhan University. The gene chip dataset GSE43696 was screened and downloaded from the high-throughput Gene Expression Omnibus (GEO) database, and the gene chip data preprocessing was completed using package "affy" in R and "rma" algorithm in turn. Use the the "edgeR" and "limma" packages to screen out the differentially expressed genes (DEGs) between normal controls, mild to moderate asthma patients and severe asthma patients, and then use the "clusterProfiler" package to perform GO enrichment analysis and KEGG pathway enrichment analysis of DEGs, finally use the STRING website to construct a protein-protein interaction (PPI) network of DEGs to further screen key genes. Using the R language "WGCNA" package, the weighted gene co-expression network analysis (WGCNA) was performed on the dataset GSE43696, and the modules significantly related to the severity of asthma were screened out, then the hub genes were obtained by intersecting the WGCNA analysis results with the DEGs screened by PPI. Datasets GSE43696 and GSE63142 were used to verify the expression of hub genes, and the diagnostic value was evaluated according to the ROC curve, then the potential function of hub genes in dataset GSE43696 was further clarified by gene set enrichment analysis (GSEA). The results showed that a total of 251 DEGs were screened, including 39 in the normal group and mild to moderate asthma group, 178 in the normal group and severe asthma group, and 34 in the mild to moderate asthma group and severe asthma group, mainly involved in biological processes such as response to toxic substance, response to oxidative stress, extracellular structure organization, extracellular matrix organization. Two modules significantly correlated with asthma severity were screened out (red module, P=7e-6, r=0.43; pink module, P=5e-8, r=-0.51), and finally six hub genes were obtained, including B3GNT6, CEACAM5, CCK, ERBB2, CSH1 and DPPA5. The comparison of gene expression levels and ROC curve analysis of datasets GSE43696 and GSE63142 further verified the six hub genes, which may associated with o-glycan biosynthesis, alpha linolenic acid metabolism, linoleic acid metabolism, pentose and glucoronate interconversions. In conclusion, through a variety of bioinformatics analysis methods, this study identified six hub genes significantly related to the severity of asthma, which potentially provided a new direction for the prediction and targeted therapy of asthma.

Contribution of monocyte and macrophage extracellular traps to neutrophilic airway inflammation in severe asthma

BackgroundIncreased blood/sputum neutrophil counts are related to poor clinical outcomes of severe asthma (SA), where we hypothesized that classical monocytes (CMs)/CM-derived macrophages (Mφ) are involved. We aimed to elucidate the mechanisms of how CMs/Mφ induce the activation of neutrophils/innate lymphoid cells (ILCs) in SA. MethodsSerum levels of monocyte chemoattractant protein-1 (MCP-1) and soluble suppression of tumorigenicity 2 (sST2) were measured from 39 patients with SA and 98 those with nonsevere asthma (NSA). CMs/Mφ were isolated from patients with SA (n = 19) and those with NSA (n = 18) and treated with LPS/interferon-gamma. Monocyte/M1Mφ extracellular traps (MoETs/M1ETs) were evaluated by western blotting, immunofluorescence, and PicoGreen assay. The effects of MoETs/M1ETs on neutrophils, airway epithelial cells (AECs), ILC1, and ILC3 were assessed in vitro and in vivo. ResultsThe SA group had significantly higher CM counts with increased migration as well as higher levels of serum MCP-1/sST2 than the NSA group. Moreover, the SA group had significantly greater production of MoETs/M1ETs (from CMs/M1Mφ) than the NSA group. The levels of MoETs/M1ETs were positively correlated with blood neutrophils and serum levels of MCP-1/sST2, but negatively correlated with FEV1%. In vitro/in vivo studies demonstrated that MoETs/M1ETs could activate AECs, neutrophils, ILC1, and ILC3 by increased migration as well as proinflammatory cytokine production. ConclusionsCM/Mφ-derived MoETs/M1ETs could contribute to asthma severity by enhancing neutrophilic airway inflammation in SA, where modulating CMs/Mφ may be a potential therapeutic option.

The role of inflammation in anxiety and depression in the European U-BIOPRED asthma cohorts

BackgroundGrowing evidence indicates high comorbid anxiety and depression in patients with asthma. However, the mechanisms underlying this comorbid condition remain unclear. The aim of this study was to investigate the role of inflammation in comorbid anxiety and depression in three asthma patient cohorts of the Unbiased Biomarkers for the Prediction of Respiratory Disease Outcomes (U-BIOPRED) project. MethodsU-BIOPRED was conducted by a European Union consortium of 16 academic institutions in 11 European countries. A subset dataset from subjects with valid anxiety and depression measures and a large blood biomarker dataset were analysed, including 198 non-smoking patients with severe asthma (SAn), 65 smoking patients with severe asthma (SAs), 61 non-smoking patients with mild-to-moderate asthma (MMA), and 20 healthy non-smokers (HC). The Hospital Anxiety and Depression Scale was used to measure anxiety and depression and a series of inflammatory markers were analysed by the SomaScan v3 platform (SomaLogic, Boulder, Colo). ANOVA and the Kruskal-Wallis test were used for multiple-group comparisons as appropriate. ResultsThere were significant group effects on anxiety and depression among the four cohort groups (p < 0.05). Anxiety and depression of SAn and SAs groups were significantly higher than that of MMA and HC groups (p < 0.05. There were significant differences in serum IL6, MCP1, CCL18, CCL17, IL8, and Eotaxin among the four groups (p < 0.05). Depression was significantly associated with IL6, MCP1, CCL18 level, and CCL17; whereas anxiety was associated with CCL17 only (p < 0.05). ConclusionsThe current study suggests that severe asthma patients are associated with higher levels of anxiety and depression, and inflammatory responses may underlie this comorbid condition.

Association between serum Vitamin D levels and asthma severity and control in children and adolescents.

To assess the association of serum Vitamin D (vitD) levels with asthma control and severity in children and adolescents in different seasons of the year. Longitudinal, prospective study with 7- to 17-year-old children and adolescents diagnosed with asthma. All participants underwent two assessments conducted in opposite seasons of the year which included a clinical assessment, a questionnaire for classification of asthma control (Asthma Control Test), spirometry, and blood collection to measure serum vitD levels. In total, 141 individuals with asthma were evaluated. The mean vitD was lower in females (p = 0.006) and sunlight exposure appears not to be an influencing factor for vitD levels. We found no differences in mean vitD of patients with controlled and uncontrolled asthma (p = 0.703; p = 0.956). However, the severe asthma group had lower mean Vitamin D than the mild/moderate asthma group for both assessments (p = 0.013; p = 0.032). In the first assessment, the group with vitD insufficiency had a higher prevalence of severe asthma (p = 0.015). Vitamin D was positively correlated with FEV1 in both assessments (p = 0.008; p = 0.006) and with FEF25-75% in the first assessment (p = 0.038). In a tropical climate zone, there is no evidence of association between seasonality and serum vitD levels or between serum vitD levels and asthma control in children and adolescents. However, vitD and lung function were positively correlated and the group with vitD insufficiency had a higher prevalence of severe asthma.

Tissue Inhibitor of Metalloproteinase-1 Enhances Eosinophilic Airway Inflammation in Severe Asthma.

Severe asthma (SA) is characterized by persistent airway inflammation and remodeling, followed by lung function decline. The present study aimed to evaluate the role of tissue inhibitor of metalloproteinase-1 (TIMP-1) in the pathogenesis of SA. We enrolled 250 adult asthmatics (54 with SA and 196 with non-SA) and 140 healthy controls (HCs). Serum TIMP-1 levels were determined by enzyme-linked immunosorbent assay. The release of TIMP-1 from airway epithelial cells (AECs) in response to stimuli as well as the effects of TIMP-1 on the activations of eosinophils and macrophages were evaluated in vitro and in vivo. Significantly higher levels of serum TIMP-1 were noted in asthmatics than in HCs, in the SA group than in non-SA group, and in the type 2 SA group than in non-type 2 SA group (P < 0.01 for all). A negative correlation between serum TIMP-1 and FEV1% values (r = -0.400, P = 0.003) was noted in the SA group. In vitro study demonstrated that TIMP-1 was released from AECs in response to poly I:C, IL-13, eosinophil extracellular traps (EETs) and in coculture with eosinophils. TIMP-1-stimulated mice showed eosinophilic airway inflammation, which was not completely suppressed by steroid treatment. In vitro and in vivo functional studies showed that TIMP-1 directly activated eosinophils and macrophages, and induced the release of EETs and macrophages to polarize toward M2 subset, which was suppressed by anti-TIMP-1 antibody. These findings suggest that TIMP-1 enhances eosinophilic airway inflammation and that serum TIMP-1 may be a potential biomarker and/or therapeutic target for type 2 SA.