Asthma Subtypes Research Articles

Subtype prevalence and treatment implication in adolescents and adults with mild-to-moderate asthma: A systematic review and meta-analysis

BackgroundInhaled corticosteroid (ICS) containing regimens are the mainstay for treating asthma despite usually being ineffective in non-eosinophilic asthma (NEA). Data on the prevalence of NEA versus eosinophilic asthma (EA) in mild-to-moderate asthmatics is limited. ObjectiveTo systematically review the subtype prevalence of mild-to-moderate asthma in adolescents and adults using sputum inflammatory cell analysis and their responses to ICS. MethodsWe searched electronic databases (PubMed, Scopus, EMBASE, Cochrane) for studies in adolescents and adults with mild-to-moderate asthma. The primary outcome was the prevalence of asthma subtypes based on sputum inflammatory cell analysis, categorized into EA and NEA. The secondary outcome involved comparing asthma outcomes between different subtypes following ICS therapy. Certainty of evidence was reported for each pooled analysis. ResultsEighteen studies involving 3,533 adolescents and adults with mild-to-moderate asthmatics were reviewed. The pooled prevalence (95% confidence interval, CI) of NEA was estimated at 40.39% (27.54, 53.93) in patients with ICS naïve with very low certainty of evidence. Upon reevaluating sputum cytology, approximately 20% to 30% of patients initially classified as having NEA transitioned to the EA subtype. EA patients showed significant improvements in asthma symptoms, FEV1 [standardized mean difference (95% CI): 0.79 (0.30, 1.27)], and airway hyperresponsiveness [1.34 (0.29, 2.40)] following ICS therapy, while NEA patients exhibited limited response. ConclusionA high proportion of adolescents and adults with mild-to-moderate asthma were identified as having the NEA subtype, which exhibited a poor response to ICS. A thorough diagnostic evaluation before initiating treatment should be integrated into clinical practice.

Pediatric Clinical Influenza Disease by Type and Subtype 2015-2020: A Multicenter, Prospective Study.

Previous investigations into clinical signs and symptoms associated with influenza types and subtypes have not definitively established differences in the clinical presentation or severity of influenza disease. The study population included children 0 through 17 years old enrolled at 8 New Vaccine Surveillance Network sites between 2015 and 2020 who tested positive for influenza virus by molecular testing. Demographic and clinical data were collected for study participants via parent/guardian interview and medical chart review. Descriptive statistics were used to summarize demographic and clinical characteristics by influenza subtype. Multivariable logistic regression and Cox proportional hazard models were used to assess effects of age, sex, influenza subtype, and history of asthma on severity, including hospital admission, need for supplemental oxygen, and length of stay. Retractions, cyanosis, and need for supplemental oxygen were more frequently observed among patients with influenza A(H1N1)pdm09. Headaches and sore throat were more commonly reported among patients with influenza B. Children with influenza A(H1N1)pdm09 and children with asthma had significantly increased odds of hospital admission (adjusted odds ratio (AOR): 1.39, 95% CI: 1.14-1.69 and AOR: 2.14, 95% CI: 1.72-2.67, respectively). During admission, children with influenza A(H1N1)pdm09 had significantly increased use of supplemental oxygen compared to children with A(H3N2) (AOR: 0.60, 95% CI: 0.44-0.82) or B (AOR: 0.56, 95% CI: 0.41-0.76). Among children presenting to the emergency department and admitted to the hospital, influenza A(H1N1)pdm09 caused more severe disease compared to influenza A(H3N2) and influenza B. Asthma also contributed to severe influenza disease regardless of subtype.

Does Eosinophil Heterogeneity Translate into Functional Diversity? A Review of the Evolving Paradigm of Eosinophil Heterogeneity in Asthma.

This review provides an overview of evidence supporting the existence of distinct homeostatic and inflammatory eosinophil subpopulations in health and disease. Particular emphasis is placed on describing the phenotypic and functional roles of these eosinophil subtypes in asthma, as well as the phenotypic changes induced by clinical therapy with the anti-IL-5 biologic agent, mepolizumab. Improved understanding of distinct eosinophil phenotypes may enable targeting of select subpopulations in the treatment of patients with type 2 inflammatory diseases such as asthma.

The Effect of Parents’ Perceived Stimulant Factors that Induce Asthma on the Quality of Life of their Children: A Cross-Sectional Study in Babylon, Iraq

Background: Asthma is a chronic respiratory condition that causes wheezing, dyspnea, and coughing. Asthma symptoms can be increased by a variety of stimulants for each asthma subtype, affecting children's quality of life. Objectives: To assess the quality of life of children with asthma, identify parents' perceived stimulant factors that influence quality of life for asthmatic children, and determine relationships between quality of life, parents' perceived stimulant factors, and demographic data for asthmatic children and their parents. Methods: From October 4, 2023, to July 1, 2024, a descriptive study was done on parents of asthmatic children in Hillah City. A nonprobability purposive sample of 155 parents of school-aged asthmatic children was obtained using a specially designed method for the study. Results: The average age of the children was 8.8±2.1 years. The majority of the children were males from rural areas, and they were diagnosed between 4 and 5 years old. Parents identified weather as the most stimulating factor, followed by infections, irritants, exercise, emotions, obesity, allergens, and some drugs. The study found that the majority of asthmatic children had a decent quality of life, while parents with a higher perception of stimulant variables have a lower quality of life. Conclusions: A high level of parents' perceived stimulant variables was negatively linked with quality of life among asthmatic children; additionally, residence, monthly income, and age of diagnosis were connected with quality of life.

LPG 18:0 is a general biomarker of asthma and inhibits the differentiation and function of regulatory T cells.

The diagnosis, severity assessment, and development of therapeutic strategies for asthma are crucial aspects of disease management. Since biomarkers are reliable tools in disease management, we aimed to identify and explore asthma-associated biomarkers and investigate their mechanisms. Lipidomics was used to profile serum glycerophospholipids in asthmatic patients and controls. The absolute concentration of lysophosphatidylglycerol (LPG) 18:0 was quantified in various asthma subtypes. Mouse asthma models were used to confirm its potential as a biomarker and investigate its mechanisms in vivo. The effects of LPG 18:0 on CD4+ T cell differentiation, proliferation, and apoptosis were assessed in vitro by flow cytometry, while mitochondrial dysfunction was evaluated through mitochondrial membrane potential, reactive oxygen species, and ATP production measurements. The intracellular mechanism of LPG 18:0 in Tregs was investigated using small molecule inhibitors. The serum glycerophospholipid profile varied between asthmatic patients and control group, with LPG 18:0 levels being notably higher in asthmatic patients, correlating with asthma severity and control level. In vivo and in vitro studies revealed that LPG18:0 impaired naïve CD4+ T cell differentiation into Tregs and compromised their suppressive function. Further investigation demonstrated that LPG18:0 treatment reduced the FOXP3 protein level via SIRT1-mediated deacetylation during Treg differentiation. This study identifies that serum levels of LPG 18:0 are generally elevated in asthmatics and serve as a biomarker for asthma. LPG 18:0 impairs Treg function via the NAD+/SIRT1/FOXP3 pathway. Our research reveals the potential of LPG18:0 as a biomarker for asthma, elucidating its role in asthma diagnosis and treatment.

Role and regulators of N6-methyladenosine (m6A) RNA methylation in inflammatory subtypes of asthma: a comprehensive review.

Asthma is a common chronic inflammatory disease of the lungs and airway, yet its inflammatory subtypes and potential pathogenesis have not been completely elucidated and require further study. With advances in epigenetic development, methylation has emerged as a new direction for identifying and decoding the occurrence and subtype manifestations of asthma. N6-methyladenosine (m6A), an RNA methylation modification occurring in the N6-position of adenosine, is a prevalent epigenetic modification observed in eukaryotes. It exerts significant control over mRNA metabolism by regulating alternative splicing, stability, export, and translation. The dynamic process of m6A methylation plays a crucial role in the pathogenesis of asthma and is tightly regulated by three types of regulators: writers, readers, and erasers. This article provides a comprehensive review of the association between m6A regulators and the pathogenesis of inflammatory subtypes of asthma, such as involvement of inflammatory cells and related inflammatory response. Furthermore, the findings presented herein provide new insights and a solid foundation for further research on m6A mRNA methylation as biomarkers for the diagnosis and development of personalized treatment for different subtypes of asthma, particularly neutrophilic asthma and eosinophilic asthma.

To investigate the function of age-related genes in different subtypes of asthma based on bioinformatics analysis

Asthma is a heterogeneous airway inflammatory disease that can be classified according to the inflammatory phenotype. The pathogenesis, clinical features, response to hormone therapy, and prognosis of different inflammatory phenotypes differ significantly. This condition also refers to age-related chronic ailments. Here, we intend to identify the function of aging-related genes in different inflammatory phenotypes of asthma using bioinformatic analyses. Initially, the research adopted the GSEA analysis to understand the fundamental mechanisms that govern different inflammatory phenotypes of asthma pathogenesis and use the CIBERSORT algorithm to assess the immune cell composition. The differentially expressed genes (DEGs) of eosinophilic asthma (EA), neutrophilic asthma (NA), and paucigranulocytic asthma (PGA) were identified through the limma R package. Aging-related genes, screened from multiple databases, were intersected with DEGs of asthma to obtain the asthma-aging-related DEGs. Then, the GO and KEGG pathway enrichment analyses showed that the NA- and EA-aging-related DEGs are involved in the various cytokine-mediated signaling pathways. PPI network and correlation analysis were performed to identify and evaluate the correlation of the hub genes. Further, the clinical characteristics of asthma-aging-related DEGs were explored through ROC analysis. 3 and 12 aging-related DEGs in EA and NA patients show high diagnostic accuracy, respectively (AUC >0.7). This study provided valuable insights into aging-related gene therapy for phenotype-specific asthma. Moreover, the study suggests that effective interventions against asthma may operate by disrupting the detrimental cycle of “aging induces metabolic diseases, which exacerbate aging".

Combining Federated Machine Learning and Qualitative Methods to Investigate Novel Pediatric Asthma Subtypes: Protocol for a Mixed Methods Study.

Pediatric asthma is a heterogeneous disease; however, current characterizations of its subtypes are limited. Machine learning (ML) methods are well-suited for identifying subtypes. In particular, deep neural networks can learn patient representations by leveraging longitudinal information captured in electronic health records (EHRs) while considering future outcomes. However, the traditional approach for subtype analysis requires large amounts of EHR data, which may contain protected health information causing potential concerns regarding patient privacy. Federated learning is the key technology to address privacy concerns while preserving the accuracy and performance of ML algorithms. Federated learning could enable multisite development and implementation of ML algorithms to facilitate the translation of artificial intelligence into clinical practice. The aim of this study is to develop a research protocol for implementation of federated ML across a large clinical research network to identify and discover pediatric asthma subtypes and their progression over time. This mixed methods study uses data and clinicians from the OneFlorida+ clinical research network, which is a large regional network covering linked and longitudinal patient-level real-world data (RWD) of over 20 million patients from Florida, Georgia, and Alabama in the United States. To characterize the subtypes, we will use OneFlorida+ data from 2011 to 2023 and develop a research-grade pediatric asthma computable phenotype and clinical natural language processing pipeline to identify pediatric patients with asthma aged 2-18 years. We will then apply federated learning to characterize pediatric asthma subtypes and their temporal progression. Using the Promoting Action on Research Implementation in Health Services framework, we will conduct focus groups with practicing pediatric asthma clinicians within the OneFlorida+ network to investigate the clinical utility of the subtypes. With a user-centered design, we will create prototypes to visualize the subtypes in the EHR to best assist with the clinical management of children with asthma. OneFlorida+ data from 2011 to 2023 have been collected for 411,628 patients aged 2-18 years along with 11,156,148 clinical notes. We expect to complete the computable phenotyping within the first year of the project, followed by subtyping during the second and third years, and then will perform the focus groups and establish the user-centered design in the fourth and fifth years of the project. Pediatric asthma subtypes incorporating RWD from diverse populations could improve patient outcomes by moving the field closer to precision pediatric asthma care. Our privacy-preserving federated learning methodology and qualitative implementation work will address several challenges of applying ML to large, multicenter RWD data. DERR1-10.2196/57981.

An antibacterial, multifunctional nanogel for efficient treatment of neutrophilic asthma

Asthma is a chronic and heterogeneous disease affecting the lungs and respiratory tract. In particular, the neutrophil subtype of asthma was described as persistent, more severe, and corticosteroid-resistant. Growing evidence suggested that nontypeable Haemophilus influenzae (NTHi) infection contributes to the development of neutrophilic asthma, exacerbating clinical symptoms and increasing the associated medical burden. In this work, arginine-grafted chitosan (CS-Arg) was ionically cross-linked with tris(2-carboxyethyl) phosphine (TCEP), and a highly-efficient antimicrobial agent, poly-ε-L-Lysine (ε-PLL), was incorporated to prepare ε-PLL/CS-Arg/TCEP (ECAT) composite nanogels. The results showed that ECAT nanogels exhibited highly effective inhibition against the proliferation of NTHi, Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). In addition, ECAT nanogels could effectively inhibit the formation of mucins aggregates in vitro, suggesting that the nanogel might have the potential to destroy mucin in respiratory disease. Furthermore, in the ovalbumin (OVA)/NTHi-induced Balb/c mice model of neutrophilic asthma, the number of neutrophils in the alveolar lavage fluid and the percentage of inflammatory cells in the blood were effectively reduced by exposure to tower nebulized administration of ECAT nanogels, and reversing airway hyperresponsiveness (AHR) and reducing inflammation in neutrophilic asthma mice. In conclusion, the construction of ECAT nanogels was a feasible anti-infective and anti-inflammatory therapeutic strategy, which demonstrated strong potential in the clinical treatment of neutrophilic asthma.

Biologic Drugs for Severe Asthma

Several biologic drugs are available to treat severe asthma. These biologics are designed to target specific inflammatory subtypes of asthma (eosinophilic or allergic). A Rapid Review was conducted to describe the evidence on the comparative efficacy and safety of biologics, and to characterize the patient populations studied. The Rapid Review was done to determine if a subsequent health technology assessment (HTA) was feasible which would be used to provide guidance on the alignment of the drug funding criteria by the public drug plans. The evidence included in the Rapid Review mainly focused on specific severe asthma subtypes. Comparing the efficacy of biologics for asthma was challenging because of differing definitions of asthma severity and inconsistent application of severity criteria in the included studies. Recruitment and outcome reporting among different asthma subgroups was limited and varied. An HTA of the existing data is unlikely to provide new insights to further inform the reimbursement of biologics in severe asthma.

Exploring the immunopathology of type 2 inflammatory airway diseases.

Significant advancements have been achieved in understanding the roles of different immune cells, as well as cytokines and chemokines, in the pathogenesis of eosinophilic airway conditions. This review examines the pathogenesis of Chronic Rhinosinusitis with Nasal Polyps (CRSwNP), marked by complex immune dysregulation, with major contributions from type 2 inflammation and dysfunctional airway epithelium. The presence of eosinophils and the role of T-cell subsets, particularly an imbalance between Treg and Th17 cells, are crucial to the disease's pathogenesis. The review also investigates the pathogenesis of eosinophilic asthma, a unique asthma subtype. It is characterized by inflammation and high eosinophil levels, with eosinophils playing a pivotal role in triggering type 2 inflammation. The immune response involves Th2 cells, eosinophils, and IgE, among others, all activated by genetic and environmental factors. The intricate interplay among these elements, chemokines, and innate lymphoid cells results in airway inflammation and hyper-responsiveness, contributing to the pathogenesis of eosinophilic asthma. Another scope of this review is the pathogenesis of Eosinophilic Granulomatosis with Polyangiitis (EGPA); a complex inflammatory disease that commonly affects the respiratory tract and small to medium-sized blood vessels. It is characterized by elevated eosinophil levels in blood and tissues. The pathogenesis involves the activation of adaptive immune responses by antigens leading to T and B cell activation and eosinophil stimulation, which causes tissue and vessel damage. On the other hand, Allergic Bronchopulmonary Aspergillosis (ABPA) is a hypersensitive response that occurs when the airways become colonized by aspergillus fungus, with the pathogenesis involving activation of Th2 immune responses, production of IgE antibodies, and eosinophilic action leading to bronchial inflammation and subsequent lung damage. This analysis scrutinizes how an imbalanced immune system contributes to these eosinophilic diseases. The understanding derived from this assessment can steer researchers toward designing new potential therapeutic targets for efficient control of these disorders.

TGF-β, IL-1β, IL-6 levels and TGF-β/Smad pathway reactivity regulate the link between allergic diseases, cancer risk, and metabolic dysregulations.

The risk of cancer is higher in patients with asthma compared to those with allergic rhinitis for many types of cancer, except for certain cancers where a contrasting pattern is observed. This study offers a potential explanation for these observations, proposing that the premalignant levels of circulating transforming growth factor-β (TGF-β), IL-1β, and IL-6 as well as the reactivity of the TGF-β/Smad signaling pathway at the specific cancer site, are crucial factors contributing to the observed disparities. Circulating TGF-β, IL- β and IL-6 levels also help clarify why asthma is positively associated with obesity, Type 2 diabetes, hypertension, and insulin resistance, whereas allergic rhinitis is negatively linked to these conditions. Furthermore, TGF-β/Smad pathway reactivity explains the dual impact of obesity, increasing the risk of certain types of cancer while offering protection against other types of cancer. It is suggested that the association of asthma with cancer and metabolic dysregulations is primarily linked to the subtype of neutrophilic asthma. A binary classification of TGF-β activity as either high (in the presence of IL-1β and IL-6) or low (in the presence or absence of IL-1β and IL-6) is proposed to differentiate between allergy patients prone to cancer and metabolic dysregulations and those less prone. Glycolysis and oxidative phosphorylation, the two major metabolic pathways utilized by cells for energy exploitation, potentially underlie this dichotomous classification by reprogramming metabolic pathways in immune cells.

The Determinants of Eosinophilia in Patients With Severe Asthma.

Asthma is defined by the Global Initiative for Asthma (GINA) as a heterogeneous disease characterized by chronic airway inflammation. The pathogenesis of the disease is better understood with the comprehension of immunological pathways. These pathways differ by the type of recruited cells and released interleukin (IL). Thus, asthma can be classified into subtypes based on the underlying immune mechanism: eosinophilic asthma (EA) and non-eosinophilic asthma (NEA). Patients with EA tend to respond better to inhaled corticosteroid as compared to those with NEA. The distinction of EA is very important in the light of emergent type 2 inflammation targeted therapies. We performed a 1-year (2018) retrospective cohort analysis of the Nationwide Inpatient Database (NIS). We included all adult patients presenting with severe asthma. Patients were stratified into two groups: eosinophilic severe asthma and non-eosinophilic severe asthma. The primary outcomes measures were the prevalence of chronic steroid use, status asthmaticus, family history of asthma, food, drug and environmental allergies, presence of nasal polyps, allergic rhinitis, allergic dermatitis, need for mechanical ventilation, need for oxygen supplementation, gastroesophageal reflux disease, in-hospital mortality, and length of stay. We performed descriptive statistics. Continuous parametric variables were reported using a mean and standard deviation. Continuous nonparametric variables were reported using a median and interquartile range. To compare the characteristics of the two groups, we used the independent t-test for continuous parametric variables and the Mann-Whitney U test for continuous nonparametric variables. The Chi-square test was used to assess differences in categorical variables. A total of 2,646 patients were included, out of which 882 belonged to the eosinophilic group and 1,764 were in the non-eosinophilic group. Comparing EA versus NEA, we have found that eosinophilic group was characterized by higher percentage of steroid use (18.3% vs. 9.5%, P < 0.001). This group also had higher rates of status asthmaticus and positive family history (P = 0.009 and 0.004, respectively). The presence of allergies, allergic rhinitis, nasal polyps, and allergic dermatitis was higher among patients with eosinophilia. The need for mechanical ventilation and supplemental oxygen was also higher among this group (P < 0.001 for both); however, there was no significant difference in mortality rate (P = 0.347) and the length of hospital stay was similar in both groups (P < 0.001). We showed herein that the eosinophilic subtype of asthma differs widely from the non-eosinophilic phenotype. Clinically, patients with eosinophilia might exhibit different symptomatology, more atopy, and concomitant comorbidities. However, this group might have better response to steroid therapy and might benefit from the new emergent T2 immune targeted therapy. The identification of EA is crucial for better disease control.

Cytokine mRNA expression in the bronchoalveolar lavage cells from horses affected by different equine asthma subtypes

Equine asthma (EA) is a respiratory syndrome associated with the increase of different leukocyte populations in the bronchoalveolar lavage fluid (BALF). Its pathogenetic mechanisms remain unclear. This study aimed to evaluate the associations between the mRNA expression of different cytokines in the BALF, different EA subtypes and lung function. Fifteen horses underwent physical examination, airway endoscopy, BALF cytology and lung function testing (8/15). One horse did not have evidence of EA and was used as healthy reference, while the others were classified as affected by neutrophilic or mixed granulocytic EA. Cells isolated from the residual BALF were used for IL-1β, IL-2, IFN-γ, IL-4, IL-17A genes expression by quantitative RT-PCR., Cytokine expression was compared between groups, and their correlations with BALF leukocyte and lung function were evaluated. IL-1β expression was positively correlated with BALF neutrophils count (p=0.038, r=0.56) and with increased expiratory resistance (p=0.047, r=0.76). IFN-γ was correlated with BALF mast cells (p=0.029, r=0.58). IL-4 was higher in horses with mixed granulocytic EA than neutrophilic (p=0.008), positively correlated with BALF mast cells (p=0.028, r=0.59) and inversely with whole-breath (p=0.046, r=-0.76) and expiratory reactance (p=0.003, r=-0.93). Finally, IL-17A was inversely correlated with expiratory reactance (p=0.009, r=-0.92). These results support that multiple immune responses are involved in EA pathogenesis; innate, Th2, and Th17 responses. Innate immunity appeared associated with neutrophilic inflammation, and Th2 response with increased mast cells. The role of Th1 response in EA remains questionable.

Eosinophilic Asthma: Pathophysiology and Therapeutic Horizons.

Asthma is a prevalent chronic non-communicable disease, affecting approximately 300 million people worldwide. It is characterized by significant airway inflammation, hyperresponsiveness, obstruction, and remodeling. Eosinophilic asthma, a subtype of asthma, involves the accumulation of eosinophils in the airways. These eosinophils release mediators and cytokines, contributing to severe airway inflammation and tissue damage. Emerging evidence suggests that targeting eosinophils could reduce airway remodeling and slow the progression of asthma. To achieve this, it is essential to understand the immunopathology of asthma, identify specific eosinophil-associated biomarkers, and categorize patients more accurately based on the clinical characteristics (phenotypes) and underlying pathobiological mechanisms (endotypes). This review delves into the role of eosinophils in exacerbating severe asthma, exploring various phenotypes and endotypes, as well as biomarkers. It also examines the current and emerging biological agents that target eosinophils in eosinophilic asthma. By focusing on these aspects, both researchers and clinicians can advance the development of targeted therapies to combat eosinophilic pathology in severe asthma.

The Relationship Between Zonulin and Asthma: A Mouse Model Study

Background and Objectives: Zonulin is a human protein that regulates intercellular tight junctions and increases the permeability of the intestinal epithelium. In light of the increasing focus on zonulin’s role in numerous chronic inflammatory diseases, this study aimed to investigate whether differences exist in serum zonulin levels and bronchial epithelium zonulin expression in vivo between asthma and normal groups, using a mouse model.Methods: Sixteen mice were utilized in this study, divided evenly between the normal and asthma groups. Serum zonulin levels, the expression of zonulin antibody in the bronchial epithelium, and serum cytokine levels were evaluated in both groups. Enzyme-linked immunosorbent assay and RNA in situ hybridization were utilized for the analysis.Results: The asthma group exhibited significantly higher levels of serum zonulin. High zonulin antibody expression was also observed in the bronchial epithelium of the asthma group. Given that our mouse model demonstrated a significant difference in interleukin (IL)-4 and IL-6 between the normal and asthma groups, zonulin may be associated not only with type 2 responses but also with various subtypes of asthma. Further studies are required to investigate this relationship in greater detail.Conclusion: Zonulin may play a role in the complex pathophysiology of asthma and could serve as a biomarker in various asthma-related situations.

Sputum microbiota and inflammatory subtypes in asthma, COPD, and its overlap

BackgroundAirway microbiota in asthma-COPD overlap (ACO) remains unknown. ObjectiveThis study with ACO-enriched population aimed to clarify airway microbiota in ACO and in mixed granulocytic inflammation, often detected in ACO and chronic airway diseases. MethodsThis is an observational cross-sectional study. Patients with asthma with airflow limitation, ACO and COPD were enrolled. Blood tests, pulmonary function, exhaled nitric oxide and sputum tests were conducted. Sputum microbiota was evaluated using the 16S rRNA gene sequencing technique. ResultsA total of 112 patients (13 asthma, 67 ACO, 32 COPD) were examined. There were no significant differences in α-diversity among the three diseases. The relative abundances of phylum Bacteroidetes, class Bacteroidia, and genus Porphyromonas were associated with decreased eosinophilic inflammation, and were significantly lower in ACO than in COPD. In a comparison of sputum inflammatory subtypes, the proportion of Haemophilus was numerically highest in the mixed granulocytic subtype, followed by the neutrophilic subtype. Likewise, the proportion of Haemophilus was the highest in the intermediate-high (2%–8%) sputum eosinophil group and lowest in the severe (8%≤) eosinophil group. Clinically, Haemophilus proportion was associated with sputum symptoms. Finally, the proportion of Streptococcus was associated with higher blood eosinophil counts and severest airflow limitation. ConclusionBacteroidia and Porphyromonas abundances in sputum are associated with the eosinophil-low phenotype, and ACO may be characterised by a decrease in these taxa. A mild elevation of sputum eosinophil does not preclude the presence of Haemophilus, which should be noted in the management of obstructive airway diseases.

Clinical Subtypes of Neutrophilic Asthma: A Cluster Analysis From Australasian Severe Asthma Network

Clinical heterogeneity may exist within asthma subtypes defined by inflammatory markers. However, the heterogeneity of neutrophilic asthma (NA) remains largely unexplored. To explore potential clusters and the stability of NA. Participants with NA from the Australasian Severe Asthma Network underwent a multidimensional assessment. They were then asked to participate in a 12-month longitudinal cohort study. We explored potential clusters using a hierarchical cluster analysis and validated the differential future risk of asthma exacerbations in the identified clusters. A decision tree analysis was developed to predict cluster assignments. Finally, the stability of prespecified clusters was examined within 1 month. Three clusters were identified in 149 patients with NA. Cluster 1 (n= 99; 66.4%) was characterized by female-predominant nonsmokers with well-controlled NA, cluster 2 (n= 16; 10.7%) by individuals with comorbid anxiety/depressive symptoms with poorly controlled NA, and cluster 3 by older male smokers with late-onset NA. Cluster 2 had a greater proportion of participants with severe exacerbations (P= .005), hospitalization (P= .010), and unscheduled visits (P= .013) and a higher number of emergency room visits (P= .039) than that of the other two clusters. The decision tree assigned 92.6% of participants correctly. Most participants (87.5%; n= 7) in cluster 2 had a stable NA phenotype, whereas participants of clusters 1 and 3 had variable phenotypes. We identified three clinical clusters of NA, in which cluster 2 represents an uncontrolled and stable NA subtype with an elevated risk of exacerbations. These findings have clinical implications for the management of NA.

Asthma Phenotypes in the Era of Personalized Medicine.

Asthma is a widespread disease affecting approximately 300-million people globally. This condition leads to significant morbidity, mortality, and economic strain worldwide. Recent clinical and laboratory research advancements have illuminated the immunological factors contributing to asthma. As of now, asthma is understood to be a heterogeneous disease. Personalized medicine involves categorizing asthma by its endotypes, linking observable characteristics to specific immunological mechanisms. Identifying these endotypic mechanisms is paramount in accurately profiling patients and tailoring therapeutic approaches using innovative biological agents targeting distinct immune pathways. This article presents a synopsis of the key immunological mechanisms implicated in the pathogenesis and manifestation of the disease's phenotypic traits and individualized treatments for severe asthma subtypes.

GOAT: Gene-level biomarker discovery from multi-Omics data using graph ATtention neural network for eosinophilic asthma subtype.

Asthma is a heterogeneous disease where various subtypes are established and molecular biomarkers of the subtypes are yet to be discovered. Recent availability of multi-omics data paved a way to discover molecular biomarkers for the subtypes. However, multi-omics biomarker discovery is challenging because of the complex interplay between different omics layers. We propose a deep attention model named Gene-level biomarker discovery from multi-Omics data using graph ATtention neural network (GOAT) for identifying molecular biomarkers for eosinophilic asthma subtypes with multi-omics data. GOAT identifies genes that discriminate subtypes using a graph neural network by modeling complex interactions among genes as the attention mechanism in the deep learning model. In experiments with multi-omics profiles of the COREA (Cohort for Reality and Evolution of Adult Asthma in Korea) asthma cohort of 300 patients, GOAT outperforms existing models and suggests interpretable biological mechanisms underlying asthma subtypes. Importantly, GOAT identified genes that are distinct only in terms of relationship with other genes through attention. To better understand the role of biomarkers, we further investigated two transcription factors, CTNNB1 and JUN, captured by GOAT. We were successful in showing the role of the transcription factors in eosinophilic asthma pathophysiology in a network propagation and transcriptional network analysis, which were not distinct in terms of gene expression level differences. Source code is available https://github.com/DabinJeong/Multi-omics_biomarker. The preprocessed data underlying this article is accessible in data folder of the github repository. Raw data are available in Multi-Omics Platform at http://203.252.206.90:5566/, and it can be accessible when requested.