Asthma: a syndrome composed of heterogeneous diseases

Association of serum pertussis antibodies with acute asthma attacks in children

Objective: The aim of this study was to examine the serum antibody levels against pertussis toxin (PT) in children experiencing an acute asthma attack and to explore the potential association between these levels and asthma. Methods: A prospective investigation was conducted, which involved 107 children with acute asthma attacks and 77 children diagnosed with bronchitis. The serum immunoglobulin G (IgG) antibody levels specific to PT were measured by using an in-house enzyme-linked immunosorbent assay. Based on the serum PT-IgG antibody levels, the children with asthma were categorized into three groups: non-pertussis infected, suspected pertussis infected, and recent pertussis infected. The clinical manifestations and pulmonary function of pediatric patients diagnosed with asthma were assessed and compared across various groups. Results: Of the total asthma group, 25 patients tested positive for PT-IgG, whereas only six patients in the bronchitis group were PT-IgG positive. The prevalence of recent pertussis infection was observed to be higher in the asthma group compared with the bronchitis group. Within the asthma group, those with recent pertussis infection exhibited a higher likelihood of experiencing wheezing and impaired lung function in comparison with the non-pertussis infection group. Conclusion: Pertussis infection is relatively common in children with asthma and correlates with the severity of asthma.

Current Challenges in Pediatric Asthma

Asthma is a chronic lung disease characterized by reversible bronchoconstriction and inflammation of the bronchi. Its increasing prevalence in childhood as well as different triggers make asthma a challenging disease in several ways: defining its phenotype/endotype, the diagnostic approach (especially in younger children), therapeutic options, and systematic follow-up. Considering these problems, this review approaches the current status and limitations of guidelines used for asthma management in children. It also emphasizes the key points which could lead to a better understanding and the direction to take in future studies.

Precision Medicine-Are We There Yet? A Narrative Review of Precision Medicine's Applicability in Primary Care

Precision medicine (PM), also termed stratified, individualised, targeted, or personalised medicine, embraces a rapidly expanding area of research, knowledge, and practice. It brings together two emerging health technologies to deliver better individualised care: the many "-omics" arising from increased capacity to understand the human genome and "big data" and data analytics, including artificial intelligence (AI). PM has the potential to transform an individual's health, moving from population-based disease prevention to more personalised management. There is however a tension between the two, with a real risk that this will exacerbate health inequalities and divert funds and attention from basic healthcare requirements leading to worse health outcomes for many. All areas of medicine should consider how this will affect their practice, with PM now strongly encouraged and supported by government initiatives and research funding. In this review, we discuss examples of PM in current practice and its emerging applications in primary care, such as clinical prediction tools that incorporate genomic markers and pharmacogenomic testing. We look towards potential future applications and consider some key questions for PM, including evidence of its real-world impact, its affordability, the risk of exacerbating health inequalities, and the computational and storage challenges of applying PM technologies at scale.

Pretreatment circulating MAIT cells, neutrophils, and periostin predicted the real-world response after 1-year mepolizumab treatment in asthmatics

BACKGROUND

Mepolizumab treatment improves symptom control and quality of life and reduces exacerbations in patients with severe eosinophilic asthma. However, biomarkers that predict therapeutic effectiveness must be determined for use in precision medicine. Herein, we elucidated the dynamics of various parameters before and after treatment as well as patient characteristics predictive of clinical responsiveness to mepolizumab after 1-year treatment.

METHODS

Twenty-seven patients with severe asthma were treated with mepolizumab for one year. Asthma control test scores, pulmonary function tests, fractional exhaled nitric oxide levels, and blood samples were evaluated. Additionally, we explored the role of CD69-positive mucosal-associated invariant T (MAIT) cells as a candidate biomarker for predicting treatment effectiveness by evaluating an OVA-induced asthma murine model using MR1 knockout mice, where MAIT cells were absent.

RESULTS

The frequencies of CD69-positive group 1 innate lymphoid cells, group 3 innate lymphoid cells, natural killer cells, and MAIT cells decreased after mepolizumab treatment. The frequency of CD69-positive MAIT cells and neutrophils was lower and serum periostin levels were higher in responders than in non-responders. In the OVA-induced asthma murine model, CD69-positive MAIT cell count in the whole mouse lung was significantly higher than that in the control mice. Moreover, OVA-induced eosinophilic airway inflammation was exacerbated in the MAIT cell-deficient MR1 knockout mice.

CONCLUSIONS

This study shows that circulating CD69-positive MAIT cells, neutrophils, and serum periostin might predict the real-world response after 1-year mepolizumab treatment. Furthermore, MAIT cells potentially have a protective role against type 2 airway inflammation.

Is sibship composition a risk factor for childhood asthma? Systematic review and meta-analysis

BACKGROUND

Following the "hygiene hypothesis", the role of sibship composition in asthma and wheezing has been extensively studied, but the findings are inconsistent. For the first time, this systematic review and meta-analysis synthesized evidences from studies investigating the association of sibship size and birth order with risk of asthma and wheezing.

METHODS

Fifteen databases were searched to identify eligible studies. Study selection and data extraction were performed independently by pairs of reviewers. Meta-analysis with robust variance estimation (RVE) was used to produce pooled risk ratio (RR) effect estimates from comparable numerical data.

RESULTS

From 17,466 identified records, 158 reports of 134 studies (> 3 million subjects) were included. Any wheezing in the last ≤ 1.5 years occurred more frequently in infants with ≥ 1 sibling [pooled RR 1.10, 95% confidence interval (CI) 1.02-1.19] and ≥ 1 older sibling (pooled RR 1.16, 95% CI 1.04-1.29). The pooled effect sizes for asthma were overall statistically nonsignificant, although having ≥ 1 older sibling was marginally protective for subjects aged ≥ 6 years (pooled RR 0.93, 95% CI 0.88-0.99). The effect estimates weakened in studies published after 2000 compared with earlier studies.

CONCLUSIONS

Being second-born or later and having at least one sibling is associated with a slightly increased risk of temporary wheezing in infancy. In contrast, being second-born or later is associated with marginal protection against asthma. These associations appear to have weakened since the turn of the millennium, possibly due to lifestyle changes and socioeconomic development. Video Abstract.

What's childhood asthma in French Guiana? A cohort study based on children referred for allergology consultations at the Cayenne hospital center

Background

Asthma is a multifactorial chronic disease, whose most frequent etiology is allergy, especially to Blomia tropicalis. In French Guiana, the childhood prevalence of Blomia T sensitization is unkwown. The aim of this study was to determine the proportion of sensitization to Blomia T and other mites in asthmatic children, and to describe the characteristics of childhood asthma in French Guiana.

Methods

A retrospective cohort study focused on children from 0 to 18 years of age, followed for asthma at the Department of Pediatrics of the Cayenne Hospital Center in French Guiana. All asthmatic children followed by the same paediatric allergist were systematically skin-tested with Bt total extract, and Bt-specific IgE tests were additionally performed to confirm specific sensitization. All follow-up variables were collected from medical records. The outcome was sensitization to Blomia tropicalis and other allergens, and the explanatory variables were those of asthma follow-up. Patients were categorized into Blomia tropicalis sensitization yes/no. Logistic regression analysis was used to assess the relationship between follow-up variables and the outcome.

Results

302 patients were followed: 177 cases of allergic rhinitis, 135 allergic conjunctivitis, 105 atopic dermatitis, 153 food allergy, and 14 cases of drug allergy. Poly-allergy (respiratory, food, skin, and medicinal) was present in 239 children. There were 158 children followed for asthma, of whom 103 (65%) were sensitized to Blomia tropicalis. The median age of the asthmatic children sensitized to Blomia tropicalis was 7 years, and 3 years for those who were not sensitized (p < 0.001). Among the girls (n = 58), 67% were sensitized to Blomia; 97 (92%) asthmatic children co-sensitized to Blomia tropicalis, Dermatophagoides pteronyssinus, and Dermatophagoides farinae. Multivariate analysis showed that the childhood asthma in French Guiana is characterized by a median age of 7 years (p < 0.001), a high prevalence of Blomia tropicalis (p < 0.001), co-sensitization to other mites (p < 0.001), and a high prevalence of co-sensitization to cockroaches (p = 0.006). The area under the ROC curve was close to 0.9, confirming the quality of our model.

Conclusion

In French Guiana, asthma is characterized by a high prevalence of Blomia tropicalis sensitization.

Global Biobank analyses provide lessons for developing polygenic risk scores across diverse cohorts

Polygenic risk scores (PRSs) have been widely explored in precision medicine. However, few studies have thoroughly investigated their best practices in global populations across different diseases. We here utilized data from Global Biobank Meta-analysis Initiative (GBMI) to explore methodological considerations and PRS performance in 9 different biobanks for 14 disease endpoints. Specifically, we constructed PRSs using pruning and thresholding (P + T) and PRS-continuous shrinkage (CS). For both methods, using a European-based linkage disequilibrium (LD) reference panel resulted in comparable or higher prediction accuracy compared with several other non-European-based panels. PRS-CS overall outperformed the classic P + T method, especially for endpoints with higher SNP-based heritability. Notably, prediction accuracy is heterogeneous across endpoints, biobanks, and ancestries, especially for asthma, which has known variation in disease prevalence across populations. Overall, we provide lessons for PRS construction, evaluation, and interpretation using GBMI resources and highlight the importance of best practices for PRS in the biobank-scale genomics era.

Multi-ancestry meta-analysis of asthma identifies novel associations and highlights the value of increased power and diversity

Asthma is a complex disease that varies widely in prevalence across populations. The extent to which genetic variation contributes to these disparities is unclear, as the genetics underlying asthma have been investigated primarily in populations of European descent. As part of the Global Biobank Meta-analysis Initiative, we conducted a large-scale genome-wide association study of asthma (153,763 cases and 1,647,022 controls) via meta-analysis across 22 biobanks spanning multiple ancestries. We discovered 179 asthma-associated loci, 49 of which were not previously reported. Despite the wide range in asthma prevalence among biobanks, we found largely consistent genetic effects across biobanks and ancestries. The meta-analysis also improved polygenic risk prediction in non-European populations compared with previous studies. Additionally, we found considerable genetic overlap between age-of-onset subtypes and between asthma and comorbid diseases. Our work underscores the multi-factorial nature of asthma development and offers insight into its shared genetic architecture.

Comparison of therapeutic response between asthma, COPD, and ACOS patients by evaluation of spirometric findings

Asthma and Chronic obstructive pulmonary disease (COPD ) both are a common public health problem that affects a large portion of population. Nearly 20% of patients with obstructive lung disease have features of both asthma and COPD called ACOS that GOLD_GINA guidelines defines as persistent airflow limitation with several features of asthma and several features of COPD. Yet there is a little data available about diagnosis and treatment of this entity and current study aimed to compare therapeutic response between asthma, COPD and Asthma-COPD overlap syndrome (ACOS) subjects through spirometric data. In the present cross-sectional study, 30 known patients with mild to moderate asthma, 30 known patients with mild to moderate COPD and 30 known patients with mild to moderate ACOS according to GOLD_GINA guidelines were enrolled. We assessed post bronchodilator the ratio of the forced expiratory volume in the first one second to the forced vital capacity of the lungs (fev1) and the forced expiratory volume in the first one second to the forced vital capacity of the lungs (fev1/fvc) in all patients. Then they took standard treatment for 2 months and after this period spirometry was repeated. Spirometric data's changes was compared between the three groups by SPSS26 statistical software. Fev1 changes in response to treatment did not differ significantly between three groups (p > 0.05) but fev1/fvc changes differed significantly and this parameter in asthma was more than ACOS and in COPD was least. (In asthma, spirometric symbolized therapeutic response is more significant than ACOS, and in ACOS, it is more important than COPD in terms of fev1/fvc changes) and there was not any difference between the three groups regarding to FEV1 changes.

Microbial dysbiosis and childhood asthma development: Integrated role of the airway and gut microbiome, environmental exposures, and host metabolic and immune response

Asthma is a chronic and heterogeneous respiratory disease with many risk factors that typically originate during early childhood. A complex interplay between environmental factors and genetic predisposition is considered to shape the lung and gut microbiome in early life. The growing literature has identified that changes in the relative abundance of microbes (microbial dysbiosis) and reduced microbial diversity, as triggers of the airway-gut axis crosstalk dysregulation, are associated with asthma development. There are several mechanisms underlying microbial dysbiosis to childhood asthma development pathways. For example, a bacterial infection in the airway of infants can lead to the activation and/or dysregulation of inflammatory pathways that contribute to bronchoconstriction and bronchial hyperresponsiveness. In addition, gut microbial dysbiosis in infancy can affect immune development and differentiation, resulting in a suboptimal balance between innate and adaptive immunity. This evolving dysregulation of secretion of pro-inflammatory mediators has been associated with persistent airway inflammation and subsequent asthma development. In this review, we examine current evidence around associations between the airway and gut microbial dysbiosis with childhood asthma development. More specifically, this review focuses on discussing the integrated roles of environmental exposures, host metabolic and immune responses, airway and gut microbial dysbiosis in driving childhood asthma development.

Allergic and hypersensitivity conditions in non-specialist care: Flow diagrams to support clinical practice

Most patients presenting with allergies are first seen by primary care health professionals. The perceived knowledge gaps and educational needs were recently assessed in response to which the LOGOGRAM Task Force was established with the remit of constructing pragmatic flow diagrams for common allergic conditions in line with an earlier EAACI proposal to develop simplified pathways for the diagnosis and management of allergic diseases in primary care. To address the lack of accessible and pragmatic guidance, we designed flow diagrams for five major clinical allergy conditions: asthma, anaphylaxis, food allergy, drug allergy, and urticaria. Existing established allergy guidelines were collected and iteratively distilled to produce five pragmatic and accessible tools to aid diagnosis and management of these common allergic problems. Ultimately, they should now be validated prospectively in primary care settings.

The 5T approach in asthma: Triple Therapy Targeting Treatable Traits

Using a therapeutic strategy that is free from traditional diagnostic labels and based on the identification of "treatable traits" (TTs), which are influential in clinical presentations in each patient, might overcome the difficulties in identifying and validating asthma phenotypes and endotypes. Growing evidence is documenting the importance of using the triple therapy with ICS, LABA, and LAMAs in a single inhaler (SITT) in cases of asthma not controlled by ICS/LABA and in the prevention of exacerbations. The identification of TTs may overcome the possibility of using SITT without considering the specific needs of the patient. In effect, it allows a treatment strategy that is closer to the precision strategy now widely advocated for the management of patients with asthma. There are different TTs in asthma that may benefit from treatment with SITT, regardless of guideline recommendations. The airflow limitation and small airway dysfunction are key TTs that are present in different phenotypes/endotypes, do not depend on the degree of T2 inflammation, and respond better than other treatments to SITT. We suggest that the 5T (Triple Therapy Targeting Treatable Traits) approach should be applied to the full spectrum of asthma, not just severe asthma, and, consequently, SITT should begin earlier than currently recommended.

Risk of Pleural Empyema in Adult Patients With Asthma: A Nationwide Retrospective Cohort Study

Background

Respiratory system infections commonly occur among individuals with asthma. However, whether asthma patients have a higher risk of pleural empyema development remains unclear.

Methods

This is a retrospective cohort study based on data from the National Health Insurance Research Database of Taiwan. The asthma cohort consisted of 48,360 newly diagnosed adult individuals from 2000 to 2012. The comparison cohort consisted of the same number of adults who did not have asthma and was matched for age, gender, comorbidity, and the year of diagnosis. The development of pleural empyema was followed up to 2013.

Results

Pleural empyema incidence was 2.03-fold higher in the asthma cohort compared to the comparison cohort (8.65 vs. 4.25 per 10,000 person-years), with an adjusted hazard ratio (HR) of 2.12 [95% confidence interval (CI) = 1.76–2.56]. Stratified analyses by age, gender, comorbidity, and corticosteroid use revealed that the crude and adjusted HRs of pleural empyema associated with asthma were all significant. Among patients with asthma, the risk of pleural empyema elevated with increased frequency of annual asthma-related emergency room visits and hospital admissions (≥1 vs. &lt;1, aHR = 8.07, 95% CI = 4.31–15.1 and aHR = 9.31, 95% CI = 5.56–15.6).

Conclusion

An increased risk of pleural empyema occurrence was observed in adult patients with asthma than those without asthma. Furthermore, the risk of pleural empyema may increase with poor control of asthma.

Association of +1923C > T, -1112C > T and +2044A > G Polymorphisms in IL-13 Gene with Susceptibility to Pediatric Asthma: A Systematic Review and Meta-Analysis

BackgroundPrevious studies have provided conflicting evidence implicating the IL-13 polymorphism and pediatric asthma. Thus, we performed a meta-analysis to combine and analyze the available studies to provide more accurate conclusions. Methods: A comprehensive retrieval in PubMed, EMBASE, Web of Science, and CNKI was performed up to February 05, 2020. Results: A total of 39 case-control studies including 15 studies with 4,968 cases and 7,091 controls were on +1923 C > T, ten studies with 3,175 cases and 2,983 controls on -1112 C > T, and 14 studies with 4,476 cases and 5,121 controls on +2044 A > G were selected. Pooled data showed that the IL-13 + 1923 C > T, -1112 C > T and +2044 A > G polymorphisms were significantly associated with risk of pediatric asthma. The IL-13 + 1923 C > T (Asians and Africans), -1112 C > T (Caucasians) and +2044 A > G (Asians) polymorphisms were more frequently associated in these ethnic groups. Conclusions: Our pooled data indicated that IL-13 + 1923 C > T, -1112 C > T and +2044 A > G polymorphisms were correlated with risk of pediatric asthma.

Qufeng Xuanbi Formula Ameliorates Airway Remodeling in Asthmatic Mice by Suppressing Airway Smooth Muscle Cell Proliferation through MEK/ERK Signaling Pathway

Asthma is a common chronic respiratory disease. The Qufeng Xuanbi formula (QFXBF), a Chinese herbal decoction, has shown efficacy in the management of asthma. The purpose of this study was to investigate the potential therapeutic effects of QFXBF in the treatment of asthma both in vitro and in vivo. Platelet-derived growth factor (PDGF)-induced airway smooth muscle cell (ASMC) proliferation and MTT assays were used to explore the effects of QFXBF on the proliferation of ASMCs. Moreover, 40 female BALB/c mice were randomly divided into five groups: control group, ovalbumin (OVA) group, high QFXBF group, low QFXBF group, and dexamethasone (DEX) group (n = 8 per group). A mouse allergic asthma model was established using the intranasally administered OVA sensitization method. Morphological changes in the lung tissue were examined by hematoxylin and eosin (H&E) staining and Masson's trichrome staining. Finally, the protein expression of alpha-smooth muscle actin (α-SMA), proliferating cell nuclear antigen (PCNA), phospho-mitogen-activated protein kinase (p-MEK1/2), mitogen-activated protein kinase (MEK1/2), phospho-extracellular signal-regulated kinases (p-ERK1/2), and extracellular signal-regulated kinases (ERK1/2) in ASMCs and lung tissue were determined by western blotting and immunofluorescent staining assays. PDGF significantly increased the viability of ASMCs. Compared with mice in the control group, the airway walls and airway smooth muscle of mice in the OVA group were thickened, and the number of inflammatory cells around the bronchus significantly increased. Moreover, the administration of QFXBF markedly inhibited the proliferation of ASMCs and alleviated the pathological changes induced by OVA. Furthermore, the protein expressions of p-ERK1/2, p-MEK1/2, PCNA, and α-SMA were significantly increased in OVA-treated mice and PDGF-treated ASMCs. Finally, treatment with QFXBF also significantly decreased the protein expression of p-ERK1/2, p-MEK1/2, α-SMA, and PCNA. QFXBF inhibited the proliferation of ASMCs by suppressing MEK/ERK signaling in PDGF-induced ASMCs and OVA-induced mice.

Abi1 mediates airway smooth muscle cell proliferation and airway remodeling via Jak2/STAT3 signaling

Asthma is a complex pulmonary disorder with multiple pathological mechanisms. A key pathological feature of chronic asthma is airway remodeling, which is largely attributed to airway smooth muscle (ASM) hyperplasia that contributes to thickening of the airway wall and further drives asthma pathology. The cellular processes that mediate ASM cell proliferation are not completely elucidated. Using multiple approaches, we demonstrate that the adapter protein Abi1 (Abelson interactor 1) is upregulated in ∼50% of ASM cell cultures derived from patients with asthma. Loss-of-function studies demonstrate that Abi1 regulates the activation of Jak2 (Janus kinase 2) and STAT3 (signal transducers and activators of transcription 3) as well as the proliferation of both nonasthmatic and asthmatic human ASM cell cultures. These findings identify Abi1 as a molecular switch that activates Jak2 kinase and STAT3 in ASM cells and demonstrate that a dysfunctional Abi1-associated pathway contributes to the progression of asthma.

lncRNA-NEAT1 Sponges miR-128 to Promote Inflammatory Reaction and Phenotypic Transformation of Airway Smooth Muscle Cells

OBJECTIVE

Pediatric asthma is still a health threat to the children. Long noncoding RNA-NEAT1 (lncRNA-NEAT1) was reported to be positively correlated with the severity of asthma. We aimed to study the effects and mechanism of lncRNA-NEAT1on inflammatory reaction and phenotypic transformation of airway smooth muscle cells (ASMCs) in the bronchial asthma.

METHOD

The degree of lncRNA-NEAT1 and miR-128 mRNA in children with bronchial asthma and healthy individuals was tested by qRT-PCR. After the inflammatory reaction and phenotypic transformation of PDGF-BB-induced ASMCs, the expression of lncRNA-NEAT1 or miR-128 in the AMSC was disturbed in the AMSC. Subsequently, the expression of lncRNA-NEAT1 and miR-128 was detected by the way of qRT-PCR, and western blot was applied to measure the expression of MMP-2, MMP-9, α-SMA, calponin, NF-κB, and so on in the cells. The content of TNF-α, IL-1β, IL-6, and IL-8 in the cell culture supernatant was checked by ELISA. MTT, Transwell, and flow cytometry were used to detect cell proliferation, migration, and apoptosis. Further, the targeting relations between lncRNA-NEAT1 and miR-128 were evaluated by the dual-luciferase reporter assay.

RESULT

In the sputum of children with bronchial asthma, lncRNA-NEAT1 was significantly upregulated while miR-128 was rapidly downregulated. Besides, lncRNA-NEAT1 and miR-128 were competitively combined and, for their expression, negatively correlated.

CONCLUSION

lncRNA-NEAT1 sponges miR-128 to boost PDGF-BB-induced inflammatory reaction and phenotypic transformation of ASMCs to aggravate the occurrence and development of childhood bronchial asthma.

Sociodemographic factors associated with time to discharge for hospitalised patients with asthma and asthma exacerbation using the Ghana Health Service District Information Management System 2 (DHIMS-2) database, 2012-2017

Objective

Data on asthma hospitalisations are a useful source of patient morbidity information. In Ghana, the length of stay (LoS) and sociodemographic factors of patients hospitalised for asthma and its exacerbation are understudied. We aimed to investigate the time to discharge and assessed factors associated with length of hospital stays of asthmatics in Ghana.

Methods

Retrospective analysis of hospitalised patient with asthma records between 2012 and 2017 from the nationwide Ghana Health Service District Health Information Management System 2 database. We calculated the cumulative incidence function for discharge stratified by age group and sex. Multivariable Cox regression was used to investigate the association of sociodemographic characteristics with the LoS.

Results

Of 19 926 asthma-associated hospitalisations, 730 (3.7%) were due to asthma exacerbation. Overall mean age was 34 years (SD=24.6), in 12 000 (60.2%) hospitalisations, patients were female. There were 224 deaths (1.1%). Median LoS was 2 days (IQR: 1–3) with almost 90% of all patients discharged by the seventh day. Age and region were among the covariates showing significant association with LoS. Age below 10 years (HR: 1.39 (1.11 to 1.78)) was associated with early discharge while comorbidity and health insurance ownership were associated with late discharge (p<0.001). LoS did not vary by sex. Compared with the Greater Accra region, patients in other regions had shorter LoS, especially the Ashanti and Upper West regions (p<0.001). LoS increased annually, but was highest in 2016 (HR: 0.94 (0.90 to 0.98)).

Conclusion

Disparities in LoS across regions, and an overall increasing annual trend in Ghana call for tailored healthcare resource allocation. Longer LoS implies that patients are often absent from school or work leading to substantial financial and emotional costs to individuals and families.

Associations Between Gut Microbiota and Asthma Endotypes: A Cross-Sectional Study in South China Based on Patients with Newly Diagnosed Asthma

Objective

This study aimed to investigate the gut microbiome profile in different inflammatory phenotypes of treatment-naive newly diagnosed asthmatic adults, to gain insight on the associations between intestinal microbiota and phenotypic features that characterize asthma heterogeneity to develop new treatments for asthma.

Methods

Fresh stool samples were obtained from 20 healthy subjects and 47 newly diagnosed asthmatic patients prior to any interventions. The asthmatics were divided into allergic and non-allergic cohorts. Intestinal microbiota was analyzed by 16S rRNA next-generation sequencing. Demographic and clinical parameters were collected. Alpha and beta diversity analysis were calculated to detect differences within sample phylotype richness and evenness between controls and asthmatic patients. Statistically significant differences between samples were analyzed for all used metrics, and features of gut bacterial community structure were evaluated in relation to extensive clinical characteristics of asthmatic patients.

Results

Gut microbial compositions were significantly different between asthmatic and healthy groups. Alpha-diversity of the gut microbiome was significantly lower in asthmatics than in controls. The microbiome between allergic and non-allergic asthmatic patients were also different, and 28 differential species were identified. PPAR signaling pathway, carotenoid biosynthesis, and flavonoid biosynthesis were significantly positively correlated with allergy-associated clinical index, including FENO value, blood eosinophil counts, and serum IgE and IL-4 levels. A combination of Ruminococcus bromii, Brevundimonas vesicularis, and Clostridium disporicum showed an AUC of 0.743 in the specific allergic/non-allergic cohort. When integrating C. disporicum, flavone, flavonol biosynthesis, and serum IL-4 values, the AUC achieved 0.929 to classify asthmatics. At the same time, C. colinum and its associated functional pathway exhibited an AUC of 0.78 to distinguish allergic asthmatics from those without allergies.

Conclusion

We demonstrated a distinct taxonomic composition of gut microbiota in different asthmatic phenotypes, highlighting their significant relationships. Our study may support considerations of intestinal microbial signatures in delineating asthma phenotypes.

Clinical effects and immune modulation of biologics in asthma

Asthma is considered a syndrome composed of heterogeneous disorders involving complex chronic airway inflammation. Patients with severe asthma, prolonged symptoms, and frequent asthma exacerbations, despite high doses of inhaled corticosteroids, may benefit from treatment with biologics. Four types of biologics are available for severe asthma, including an anti-immunoglobulin E (IgE) antibody (omalizumab), anti-interleukin (IL)-5 antibody (mepolizumab and reslizumab), anti-IL-5 receptor α antibody (benralizumab), and anti-IL-4 receptor α antibody (dupilumab). Biologics for patients with severe asthma demonstrate high therapeutic efficacy and provide significant clinical benefits, including the prevention of asthma exacerbations, alleviation of symptoms, improvement in the quality of life and respiratory function, and reduction in frequencies of hospitalization and emergency outpatient visits. This review provides an overview of the modulation of immunological features by each of the four established biologics in patients with severe allergic asthma. Given the extensive immunomodulatory effects of biologics, further analyses of their precise effects on the human immune system are warranted.

Asthma-COPD overlap: current understanding and the utility of experimental models

Pathological features of both asthma and COPD coexist in some patients and this is termed asthma-COPD overlap (ACO). ACO is heterogeneous and patients exhibit various combinations of asthma and COPD features, making it difficult to characterise the underlying pathogenic mechanisms. There are no controlled studies that define effective therapies for ACO, which arises from the lack of international consensus on the definition and diagnostic criteria for ACO, as well as scant in vitro and in vivo data. There remain unmet needs for experimental models of ACO that accurately recapitulate the hallmark features of ACO in patients. The development and interrogation of such models will identify underlying disease-causing mechanisms, as well as enabling the identification of novel therapeutic targets and providing a platform for assessing new ACO therapies. Here, we review the current understanding of the clinical features of ACO and highlight the approaches that are best suited for developing representative experimental models of ACO.

Understanding the pathogenesis of asthma-COPD overlap is critical for improving therapeutic approaches. We present current knowledge on asthma-COPD overlap and the requirements for developing an optimal animal model of disease.https://bit.ly/3lsjyvm

Investigating asthma heterogeneity through shared and distinct genetics: Insights from genome-wide cross-trait analysis

Asthma is a heterogeneous respiratory disease reflecting distinct pathobiologic mechanisms. These mechanisms are based, at least partly, on different genetic factors shared by many other conditions, such as allergic diseases and obesity. Investigating the shared genetic effects enables better understanding of the mechanisms of phenotypic correlations and is less subject to confounding by environmental factors. The increasing availability of large-scale genome-wide association study (GWAS) for asthma has enabled researchers to examine the genetic contributions to the epidemiologic associations between asthma subtypes and those between coexisting diseases and/or traits and asthma. Studies have found not only shared but also distinct genetic components between asthma subtypes, indicating that the heterogeneity is related to distinct genetics. This review summarizes a recently compiled analytic approach-genome-wide cross-trait analysis-to determine shared and distinct genetic architecture. The genome-wide cross-trait analysis features in several analytic aspects: genetic correlation, cross-trait meta-analysis, Mendelian randomization, polygenic risk score, and functional analysis. In this article, we discuss in detail the scientific goals that can be achieved by these analyses, their advantages, and their limitations. We also make recommendations for future directions: (1) ethnicity-specific asthma GWASs and (2) application of cross-trait methods to multiomics data to dissect the heritability found in GWASs. Finally, these analytic approaches are also applicable to complex and heterogeneous traits beyond asthma.

YiQi GuBen Formula Inhibits PDGF-BB-Induced Proliferation and Migration of Airway Smooth Muscle Cells

OBJECTIVE

Increased proliferation and migration of airway smooth muscle cells (ASMCs) are key events in the development of asthma. YiQi GuBen is a traditional Chinese medicinal formula shown to effectively reduce the recurrence rate of asthma and induce anti-asthma effects through multiple pathways; however, its potential role in regulating ASMC proliferation and preventing bronchial asthma remains unexplored.

METHODS

This study investigated the effects of YiQi GuBen formula on platelet-derived growth factor (PDGF)-BB-induced ASMC proliferation and migration by methylthiazolyldiphenyl-tetrazolium bromide, wound healing, transwell, and cell cycle assays. The influence of YiQi GuBen formula on nuclear factor-κB (NF-κB) signaling-relevant proteins was measured by Western blotting, real-time quantitative PCR (RT-qPCR) assay, and ELISA.

RESULTS

We found that pretreatment with YiQi GuBen formula had a dose-dependent inhibitory effect on PDGF-BB-stimulated ASMC proliferation. It also suppressed PDGF-BB-induced ASMC migration and arrested PDGF-BB-induced cell cycle progression. Furthermore, YiQi GuBen formula suppressed PDGF-BB-induced expression of phosphorylated p65 and the release of inflammatory factors TNF-α, IL-1β, IL-6, and IL-8 in ASMCs.

CONCLUSIONS

In summary, our study shows that YiQi GuBen formula is able to significantly inhibit PDGF-BB-induced ASMC proliferation and migration by suppressing the NF-κB signaling pathway.

Association between prenatal exposure to perfluoroalkyl substances and asthma in 5-year-old children in the Odense Child Cohort

BACKGROUND

Asthma is the most common non-communicable disease in children. Prenatal exposure to perfluoroalkyl substances (PFASs), a group of persistent environmental chemicals with endocrine disrupting abilities, has been associated with immunomodulation and may contribute to the aetiology of asthma. We investigated the associations between prenatal exposure to five PFASs and asthma in 5-year-old children.

METHODS

We studied 981 mother-child pairs within the Odense Child Cohort (OCC), Denmark. We measured perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), perfluorononanoic acid (PFNA) and perfluorodecanoic acid (PFDA) in maternal serum donated in early pregnancy. A standardized questionnaire based on the International Study of Asthma and Allergies in Childhood (ISAAC) was used to assess wheeze, self-reported asthma and doctor-diagnosed asthma among children at age 5 years. Associations were examined using logistic regression analyses adjusting for parity, maternal educational level, maternal pre-pregnancy BMI, asthma predisposition and child sex.

RESULTS

Among the 5-year-old children 18.6% reported wheeze and 7.1% reported asthma. We found no association between prenatal exposure to PFAS and doctor-diagnosed asthma or wheeze. Prenatal PFAS exposure was associated with self-reported asthma, although only significant for PFNA (OR = 1.84, 95% CI 1.03,3.23).

CONCLUSION

Our findings support the suggested immunomodulatory effects of PFASs, however, additional studies are warranted. In order to verify our findings, it is important to re-examine the children with postnatal measurements of serum PFAS concentrations and additional clinical diagnostic testing at an older age where an asthma diagnosis is more valid.

Associations between fungal and bacterial microbiota of airways and asthma endotypes

BACKGROUND

The relationship between asthma, atopy, and underlying type 2 (T2) airway inflammation is complex. Although the bacterial airway microbiota is known to differ in asthmatic patients, the fungal and bacterial markers that discriminate T2-high (eosinophilic) and T2-low (neutrophilic/mixed-inflammation) asthma and atopy are still incompletely identified.

OBJECTIVES

The aim of this study was to demonstrate the fungal microbiota structure of airways in asthmatic patients associated with T2 inflammation, atopy, and key clinical parameters.

METHODS

We collected endobronchial brush (EB) and bronchoalveolar lavage (BAL) samples from 39 asthmatic patients and 19 healthy subjects followed by 16S gene and internal transcribed spacer-based microbiota sequencing. The microbial sequences were classified into exact sequence variants. The T2 phenotype was defined by using a blood eosinophil count with a threshold of 300 cells/μL.

RESULTS

Fungal diversity was significantly lower in EB samples from patients with T2-high compared with T2-low inflammation; key fungal genera enriched in patients with T2-high inflammation included Trichoderma species, whereas Penicillium species was enriched in patients with atopy. In BAL fluid samples the dominant genera were Cladosporium, Fusarium, Aspergillus, and Alternaria. Using generalized linear models, we identified significant associations between specific fungal exact sequence variants and FEV1, fraction of exhaled nitric oxide values, BAL fluid cell counts, and corticosteroid use. Investigation of interkingdom (bacterial-fungal) co-occurrence patterns revealed different topologies between asthmatic patients and healthy control subjects. Random forest models with fungal classifiers predicted asthma status with 75% accuracy for BAL fluid samples and 80% accuracy for EB samples.

CONCLUSIONS

We demonstrate clear differences in bacterial and fungal microbiota in asthma-associated phenotypes. Our study provides additional support for considering microbial signatures in delineating asthma phenotypes.

Inhaled Janus Kinase (JAK) inhibitors for the treatment of asthma

Multiple asthma-relevant cytokines including IL-4, IL-5, IL-13, and TSLP depend upon JAKs for signaling. JAK inhibition may, therefore, offer a novel intervention strategy for patients with disease refractory to current standards of care. Multiple systemically delivered JAK inhibitors have been approved for human use or are under clinical evaluation in autoimmune diseases such as rheumatoid arthritis. However, the on-target side effect profiles of these agents are likely not tolerable for many asthmatic patients. Limiting JAK inhibition to the lung is expected to improve therapeutic index relative to systemic inhibition. Thus, inhaled JAK inhibitors with lung-restricted exposure are of high interest as potential treatments for asthma.

Asthma Diagnosis: The Changing Face of Guidelines

Asthma, the most common chronic respiratory disease, is frequently misdiagnosed, and accounts for a significant proportion of healthcare expenditure. This has driven the National Institute for Health and Care Excellence (NICE) in the United Kingdom (UK) to produce recent guidance; in places, this contrasts to that of the British Thoracic Society/Scottish Intercollegiate Guideline Network (BTS/SIGN), which have been producing their own guidance since 2003. Here we review the history of asthma diagnostic guidelines, and compare and review the evidence behind them, in adults and in children. We discuss the definitions of asthma and how these drive the concepts behind diagnostic strategies. We anticipate future directions in asthma diagnosis which will take into account the concepts of personalised medicine and disease endotypes. We also consider the utility of tests in use now and in the future, in particular novel tests relating to small airway inflammation and obstruction.

The crosstalk between microbiome and asthma: Exploring associations and challenges

With the advancement of high‐throughput DNA/RNA sequencing and computational analysis techniques, commensal bacteria are now considered almost as important as pathological ones. Understanding the interaction between these bacterial microbiota, host and asthma is crucial to reveal their role in asthma pathophysiology. Several airway and/or gut microbiome studies have shown associations between certain bacterial taxa and asthma. However, challenges remain before gained knowledge from these studies can be implemented into clinical practice, such as inconsistency between studies in choosing sampling compartments and/or sequencing approaches, variability of results in asthma studies, and not taking into account medication intake and diet composition especially when investigating gut microbiome. Overcoming those challenges will help to better understand the complex asthma disease process. The therapeutic potential of using pro‐ and prebiotics to prevent or reduce risk of asthma exacerbations requires further investigation. This review will focus on methodological issues regarding setting up a microbiome study, recent developments in asthma bacterial microbiome studies, challenges and future therapeutic potential.

Cohort profile: the West Sweden Asthma Study (WSAS): a multidisciplinary population-based longitudinal study of asthma, allergy and respiratory conditions in adults

PURPOSE

The West Sweden Asthma Study (WSAS) is a population-representative longitudinal study established to: (1) generate data on prevalence trends, incidence and remission of asthma, allergy and respiratory conditions, (2) elucidate on the risk and prognostic factors associated with these diseases, (3) characterise clinically relevant phenotypes of these diseases and (4) catalyse relevant mechanistic, genomic, genetic and translational investigations.

PARTICIPANTS

WSAS comprised of randomly selected individuals aged 16 to 75 years who are followed up longitudinally. The first stage involved a questionnaire survey (>42 000 participants) and was undertaken in 2008 and 2016. A random sample (about 8000) of participants in the initial survey undergoes extensive clinical investigations every 8 to 10 years (first investigations in 2009 to 2012, second wave currently ongoing). Measurements undertaken at the clinical investigations involve structured interviews, self-completed questionnaire on personality traits, physical measurements and extensive biological samples.

FINDINGS TO DATE

Some of our key findings have shown a 54% increase in the use of asthma medications between the 1990s and 2000s, primarily driven by a five-fold increase in the use of inhaled corticosteroids. About 36% of asthmatics expressed at least one sign of severe asthma indicator, with differential lung performance, inflammation and allergic sensitisation among asthmatics with different signs of severe asthma. Multi-symptom asthmatics were at greater risk of having indicators of severe asthma. In all adults, being raised on a farm was associated with a decreased risk of allergic sensitisation, rhinitis and eczema, but not asthma. However, among adolescents (ie, those 16 to 20 years of age), being raised on a farm decreased the risk of asthma. Personality traits were associated with both beliefs of asthma medication and adherence to treatment.

FUTURE PLANS

Follow-up of the cohort is being undertaken every 8 to 10 years. The repeated clinical examinations will take place in 2019 to 2022. The cohort data are currently being linked to routine Swedish healthcare registers for a continuous follow-up. Mechanistic, genomic, genetic and translational investigations are ongoing.

Differences in the risk of mood disorders in patients with asthma-COPD overlap and in patients with COPD alone: a nationwide population-based retrospective cohort study in Korea

BACKGROUND

Although feelings of anxiety and depression are common in patients with chronic obstructive pulmonary disease (COPD), little is known about the estimates of their incidence in patients with asthma-COPD overlap (ACO), which has been described and acknowledged as a distinct clinical entity. We aimed to estimate the risk of depression and anxiety among patients with ACO and compare it with the risk among those with COPD alone in the general population.

METHODS

We conducted a nationwide population-based retrospective cohort study using the Korean National Sample Cohort database between 1 January, 2002, and 31 December, 2013. Patients who were diagnosed with COPD (International Classification of Diseases, 10th revision [ICD-10] codes J42-J44) at least twice and prescribed COPD medications at least once between 2003 and 2011 were classified into two categories: patients who were diagnosed with asthma (ICD-10 codes J45-J46) more than twice and at least once prescribed asthma medications comprised the ACO group, and the remaining COPD patients comprised the COPD alone group. Patients who had been diagnosed with depression or anxiety within a year before the index date were excluded. We defined the outcome as time to first diagnosis with depression and anxiety. Matched Cox regression models were used to compare the risk of depression and anxiety among patients with ACO and patients with COPD alone after propensity score matching with a 1:1 ratio.

RESULTS

After propensity score estimation and matching in a 1:1 ratio, the cohort used in the analysis included 15,644 patients. The risk of depression during the entire study period was higher for patients with ACO than for patients with COPD alone (adjusted hazard ratio, 1.10; 95% confidence interval, 1.03-1.18; P value = 0.0039), with an elevated risk in patients aged 40-64 years (1.21; 1.10-1.34; 0.0001) and in women (1.18; 1.07-1.29; 0.0005). The risk of anxiety was higher for patients with ACO than for patients with COPD alone (1.06; 1.01-1.12; 0.0272), with a higher risk in patients aged 40-64 years (1.08; 1.00-1.17; 0.0392); however, the risk was not significant when stratified by sex.

CONCLUSIONS

This population-based study revealed a higher incidence of depression and anxiety in patients with ACO than in patients with COPD alone.

Pediatric asthma comprises different phenotypic clusters with unique nasal microbiotas

BACKGROUND

Pediatric asthma is the most common chronic childhood disease in the USA, currently affecting ~ 7 million children. This heterogeneous syndrome is thought to encompass various disease phenotypes of clinically observable characteristics, which can be statistically identified by applying clustering approaches to patient clinical information. Extensive evidence has shown that the airway microbiome impacts both clinical heterogeneity and pathogenesis in pediatric asthma. Yet, so far, airway microbiotas have been consistently neglected in the study of asthma phenotypes. Here, we couple extensive clinical information with 16S rRNA high-throughput sequencing to characterize the microbiota of the nasal cavity in 163 children and adolescents clustered into different asthma phenotypes.

RESULTS

Our clustering analyses identified three statistically distinct phenotypes of pediatric asthma. Four core OTUs of the pathogenic genera Moraxella, Staphylococcus, Streptococcus, and Haemophilus were present in at least 95% of the studied nasal microbiotas. Phyla (Proteobacteria, Actinobacteria, and Bacteroidetes) and genera (Moraxella, Corynebacterium, Dolosigranulum, and Prevotella) abundances, community composition, and structure varied significantly (0.05 < P ≤ 0.0001) across asthma phenotypes and one of the clinical variables (preterm birth). Similarly, microbial networks of co-occurrence of bacterial genera revealed different bacterial associations across asthma phenotypes.

CONCLUSIONS

This study shows that children and adolescents with different clinical characteristics of asthma also show different nasal bacterial profiles, which is indicative of different phenotypes of the disease. Our work also shows how clinical and microbial information could be integrated to validate and refine asthma classification systems and develop biomarkers of disease.

Using a Mixture-of-Bivariate-Regressions Model to Explore Heterogeneity of Effects of the Use of Inhaled Corticosteroids on Gestational Age and Birth Weight Among Pregnant Women With Asthma

Asthma is a heterogeneous disease, and responses to asthma medications vary noticeably among patients. A substantively oriented objective of this study was to explore the potentially heterogeneous effects of exposure to maternal inhaled corticosteroids (ICS) on gestational age (GA) at delivery and birth weight (BW) using a cohort of 6,197 pregnancies among women with asthma (Quebec, Canada, 1998-2008). A methodologically oriented objective was to comprehensively describe the application of a Bayesian 2-component mixture-of-bivariate-regressions model to address this issue and estimate the effects of ICS on GA and BW jointly. Based on the proposed model, no association between ICS and GA/BW was found for a large proportion of asthmatic pregnancies. However, a positive association between ICS exposure and GA/BW was revealed in a small subset of pregnancies comprising mainly preterm and low-birth-weight infants. A novel application of this model was also subsequently performed using BW z score instead of BW as the outcome variable. In conclusion, the studied mixture-of-bivariate-regressions model was useful for detecting heterogeneity in the effect of ICS on GA and BW in our population of women with asthma. These analyses pave the way for analogous uses of this model for general assessment of exposure effect heterogeneity for these perinatal outcomes.

Are We There Yet? How and When Specific Biotechnologies Will Improve Human Health

Patient X: A 67-year-old Caucasian man slips on a patch of ice. He has abrasions to his hands and has sustained significant damage to his hip. At the emergency room, he informs clinicians he takes atorvastatin, metformin, and glimepiride to treat hypertension and Type 2 Diabetes Mellitus (T2DM). X-rays reveal a fractured hip, which will require total hip replacement surgery.

A Bayesian finite mixture of bivariate regression model for causal mediation analyses

Building on the work of Schwartz et al, Joint Bayesian analysis of birthweight and censored gestational age using finite mixture models in Statistics in Medicine, we propose a Bayesian finite mixture of bivariate regression model for causal mediation analyses. Using an identifiability condition within each component of the mixture, we express the natural direct and indirect effects of the exposure on the outcome as functions of the component-specific regression coefficients. On the basis of simulated data, we examine the behavior of the model for estimating these effects in situations where the associations between exposure, mediator, and outcome are confounded or not. Additionally, we demonstrate that this mixture model can be used to account for heterogeneity arising through unmeasured binary or categorical mediator-outcome confounders. Considering gestational age as a potential mediator, we then illustrate our mediation mixture model to estimate the natural direct and indirect effects of exposure to inhaled corticosteroids during pregnancy on birthweight using a cohort of asthmatic women from the province of Quebec (Canada).

African ancestry is associated with cluster-based childhood asthma subphenotypes

BACKGROUND

Childhood asthma is a syndrome composed of heterogeneous phenotypes; furthermore, intrinsic biologic variation among racial/ethnic populations suggests possible genetic ancestry variation in childhood asthma. The objective of the study is to identify clinically homogeneous asthma subphenotypes in a diverse sample of asthmatic children and to assess subphenotype-specific genetic ancestry in African-American asthmatic children.

METHODS

A total of 1211 asthmatic children including 813 in the Childhood Asthma Management Program and 398 in the Childhood Asthma Research and Education program were studied. Unsupervised cluster analysis on clinical phenotypes was conducted to identify homogeneous subphenotypes. Subphenotype-specific genetic ancestry was estimated for 167 African-American asthmatic children. Genetic ancestry association with subphenotypes/clinical phenotypes were determined.

RESULTS

Three distinct subphenotypes were identified: a moderate atopic dermatitis (AD) group with negative skin prick test (SPT) and preserved lung function; a high AD group with positive SPT and airway hyperresponsiveness; and a low AD group with positive SPT and lower lung function. African ancestry at asthma genome-wide association study (GWAS) SNPs differed between subphenotypes (64, 89, and 94% for the three subphenotypes, respectively) and was inversely correlated with AD; each additional 10% increase in African ancestry was associated with 1.5 fold higher in IgE and 6.3 higher odds of positive SPT (all p-values < 0.0001).

CONCLUSIONS

By conducting phenotype-based cluster analysis and assessing subphenotype-specific genetic ancestry, we were able to identify homogeneous subphenotypes for childhood asthma that showed significant variation in genetic ancestry of African-American asthmatic children. This finding demonstrates the utility of these complementary approaches to understand and refine childhood asthma subphenotypes and enable more targeted therapy.

Variants in genes coding for glutathione S-transferases and asthma outcomes in children

Our hypothesis was that children with mutations in genes coding for glutathione S-transferases (GST) have worse asthma outcomes compared with children with active type genotype. Data were collected in five populations. The rs1695 single nucleotide polymorphism (GSTP1) was determined in all cohorts (3692 children) and GSTM1 and GSTT1 null genotype were determined in three cohorts (2362 children). GSTT1 null (but not other genotypes) was associated with a minor increased risk for asthma attack and there were no significant associations between GST genotypes and asthma severity. Interactions between GST genotypes and SHS exposure or asthma severity with the study outcomes were nonsignificant. We find no convincing evidence that the GST genotypes studied are related to asthma outcomes.

Therapeutic antibodies: A new era in the treatment of respiratory diseases?

Respiratory diseases affect millions of people worldwide, and account for significant levels of disability and mortality. The treatment of lung cancer and asthma with therapeutic antibodies (Abs) is a breakthrough that opens up new paradigms for the management of respiratory diseases. Antibodies are becoming increasingly important in respiratory medicine; dozens of Abs have received marketing approval, and many more are currently in clinical development. Most of these Abs target asthma, lung cancer and respiratory infections, while very few target chronic obstructive pulmonary disease - one of the most common non-communicable causes of death - and idiopathic pulmonary fibrosis. Here, we review Abs approved for or in clinical development for the treatment of respiratory diseases. We notably highlight their molecular mechanisms, strengths, and likely future trends.

Genetic Mechanisms of Asthma and the Implications for Drug Repositioning

Asthma is a chronic disease that is caused by airway inflammation. The main features of asthma are airway hyperresponsiveness (AHR) and reversible airway obstruction. The disease is mainly managed using drug therapy. The current asthma drug treatments are divided into two categories, namely, anti-inflammatory drugs and bronchodilators. However, disease control in asthma patients is not very efficient because the pathogenesis of asthma is complicated, inducing factors that are varied, such as the differences between individual patients. In this paper, we delineate the genetic mechanisms of asthma, and present asthma-susceptible genes and genetic pharmacology in an attempt to find a diagnosis, early prevention, and treatment methods for asthma. Finally, we reposition some clinical drugs for asthma therapy, based on asthma genetics.

Variation in the TEK gene is not associated with asthma but with allergic conjunctivitis

The Tie2 receptor is an important player in angiogenesis. The Tie2 mRNA and protein are abundantly expressed in the lungs and the associated pathway also has an important role in the development and function of the eye. Tie2 is encoded by the TEK gene in humans. Recently, variations in the TEK gene have been found associated with asthma. The objective of the present study was to investigate whether variations in the TEK gene influenced the susceptibility to pediatric asthma and/or associated phenotypes like GINA status, viral- or exercise-induced asthma, allergic asthma, indoor, outdoor, inhalative allergies, IgE and eosonophil levels, allergic rhinitis and allergic conjunctivitis. Three single nucleotide polymorphisms (SNPs, rs3780315, rs581724 and rs7876024) in the TEK gene were genotyped in 1189 unrelated individuals, out of which 435 were asthmatic children and 754 healthy controls. Different types of asthma, allergies and co-morbidities were defined in 320 patients. Among the fully phenotyped 320 asthmatic patients 178 (55.6%) also had allergic rhinitis and 100 (31.3%) had conjunctivitis. Among the rhinitis patients 98 (55.1%) also had conjunctivitis. Two patients had conjunctivitis without rhinitis. The genotyped SNPs showed no association with asthma. However, SNP rs581724 was significantly associated with allergic conjunctivitis in a recessive way (p=0.007; OR=2.3 (1.3-4.4)) within the asthmatic population. The risk remained significant when the whole population (asthmatics and healthy controls) was included in the calculation (p = 0.003; OR = 2.1 (1.3-3.6)). The minor allele of the rs581724 SNP which is associated with the increased risk to conjunctivitis is also associated with reduced Tie2 expression. There was a significant association between SNP rs581724 and the occurrence of allergic conjunctivitis in asthmatic children. If additional studies can confirm the role of the Tie2 pathway in allergic conjunctivitis, it can be a potential novel therapeutic target in the disease.

The MEGA Project: A Study of the Mechanisms Involved in the Genesis and Disease Course of Asthma. Asthma Cohort Creation and Long-Term Follow-Up

The general aim of this study is to create a cohort of asthma patients with varying grades of severity in order to gain greater insight into the mechanisms underlying the genesis and course of this disease. The specific objectives focus on various studies, including imaging, lung function, inflammation, and bronchial hyperresponsiveness, to determine the relevant events that characterize the asthma population, the long-term parameters that can determine changes in the severity of patients, and the treatments that influence disease progression. The study will also seek to identify the causes of exacerbations and how this affects the course of the disease. Patients will be contacted via the outpatient clinics of the 8 participating institutions under the auspices of the Spanish Respiratory Diseases Networking System (CIBER). In the inclusion visit, a standardized clinical history will be obtained, a clinical examination, including blood pressure, body mass index, complete respiratory function tests, and FENO will be performed, and the Asthma Control Test (ACT), Morisky-Green test, Asthma Quality of Life Questionnaire (Mini AQLQ), the Sino-Nasal Outcome Test 22 (SNOT-22), and the Hospital Anxiety and Depression scale (HADS) will be administered. A specific electronic database has been designed for data collection. Exhaled breath condensate, urine and blood samples will also be collected. Non-specific bronchial hyperresponsiveness testing with methacholine will be performed and an induced sputum sample will be collected at the beginning of the study and every 24 months. A skin prick test for airborne allergens and a chest CT will be performed at the beginning of the study and repeated every 5 years.

The use of fractional exhaled nitric oxide is valuable in select asthmatic patients

PURPOSE OF REVIEW

Clinical management of asthma is challenging and measuring fractional exhaled nitric oxide (FeNO) can be another tool to assist in meeting this challenge.

RECENT FINDINGS

Asthma is a heterogeneous condition. There are many different phenotypes. FeNO can help the physician identify which patients have eosinophilic inflammation and would potentially respond to corticosteroid therapy.

SUMMARY

FeNO is a complement to standard asthma care. FeNO can be used in the initial diagnosis of asthma and aid in stratification of which patients would be steroid responsive but also for assessment of disease severity, response to treatment, and compliance.

Asthma biomarkers in the age of biologics

The heterogeneous nature of asthma has been understood for decades, but the precise categorization of asthma has taken on new clinical importance in the era of specific biologic therapy. The simple categories of allergic and non-allergic asthma have given way to more precise phenotypes that hint at underlying biologic mechanisms of variable airflow limitation and airways inflammation. Understanding these mechanisms is of particular importance for the approximately 10% of patients with severe asthma. Biomarkers that aid in phenotyping allow physicians to "personalize" treatment with targeted biologic agents. Unfortunately, testing for these biomarkers is not routine in patients whose asthma is refractory to standard therapy. Scientific advances in the recognition of sensitive and specific biomarkers are steadily outpacing the clinical availability of reliable and non-invasive assessment methods designed for the prompt and specific diagnosis, classification, treatment, and monitoring of severe asthma patients. This article provides a practical overview of current biomarkers and testing methods for prompt, effective management of patients with severe asthma that is refractory to standard therapy.

Can learning health systems help organisations deliver personalised care?

There is increasing international policy and clinical interest in developing learning health systems and delivering precision medicine, which it is hoped will help reduce variation in the quality and safety of care, improve efficiency, and lead to increasing the personalisation of healthcare. Although reliant on similar policies, informatics tools, and data science and implementation research capabilities, these two major initiatives have thus far largely progressed in parallel. In this opinion piece, we argue that they should be considered as complementary, synergistic initiatives whereby the creation of learning health systems infrastructure can support and catalyse the delivery of precision medicine that maximises the benefits and minimises the risks associated with treatments for individual patients. We illustrate this synergy by considering the example of treatments for asthma, which is now recognised as an umbrella term for a heterogeneous group of related conditions.

Mechanisms Driving Gender Differences in Asthma

PURPOSE OF REVIEW

Many phenotypes of asthma exist, ranging from mild asthma with onset during childhood to severe asthma with later onset, making asthma a broad disease with different pathologies. A gender disparity exists in asthma prevalence. As adults, women have an increased asthma prevalence compared to men. Further, women are more likely to have severe asthma and a later onset of asthma compared to men. Here, we review clinical and animal studies that have defined the role of sex hormones in airway inflammation, smooth muscle contraction, mucus production, and airway mechanics associated with asthma pathogenesis.

RECENT FINDINGS

Clinical evidence shows that increased asthma symptoms occur in females starting at puberty compared to those in boys. However, after puberty, the role for sex hormones in regulating asthma symptoms during menstruation, pregnancy, and menopause is not as clear. Animal studies have shown that estrogen increases and testosterone decreases Th2-mediated airway inflammation, and that females have increased IL-17A-mediated airway inflammation compared to males. Further, females had increased DC and Mϕ function compared to males. However, the mechanisms driving the types of allergic inflammation are not fully elucidated. Overall, ovarian hormones increased and testosterone decreased airway inflammation in asthma, but the mechanisms remain unclear. Delineating these pathways using animal models as well as women and men with various phenotypes of asthma will help determine if women with asthma should take (or avoid) hormonal contraceptives as well as predict changes in asthma symptoms during life phases, including pregnancy and menopause, when sex hormones are dramatically changing.

Risk of Periodontal Disease in Patients With Asthma: A Nationwide Population-Based Retrospective Cohort Study

BACKGROUND

Studies have reported an association between asthma and oral diseases, including periodontal diseases. The aim of this retrospective study is to investigate risk of periodontal diseases for patients with asthma.

METHODS

Using the claims data of National Health Insurance of Taiwan and patients without a history of periodontal diseases, 19,206 asthmatic patients, who were newly diagnosed from 2000 through 2010, were identified. For each case, four comparison individuals without history of asthma and periodontal disease were randomly selected from the general population and frequency matched (categorical matched) by sex, age, and year of diagnosis (n = 76,824). Both cohorts were followed to the end of 2011 to monitor occurrence of periodontal diseases. Adjusted hazard ratios (aHRs) of periodontal disease were estimated using Cox proportional hazards regression analysis.

RESULTS

Overall incidence of periodontal diseases was 1.18-fold greater in the asthma cohort than in the comparison cohort (P <0.001). Patients with at least three emergency visits annually had an aHR of 55.9 (95% confidence interval [CI] = 50.6 to 61.7) for periodontal diseases compared with those with a mean of less than one visit. Patients with at least three admissions annually also had a similar aHR (51.8) for periodontal disease. In addition, asthmatic patients on inhaled corticosteroid (ICS) therapy had greater aHRs than non-users (aHR = 1.12; 95% CI = 1.03 to 1.23).

CONCLUSIONS

In the studied population, asthmatic patients are at an elevated risk of developing periodontal diseases. The risk is much greater for those with emergency medical demands or hospital admissions and those on ICS treatment.

Linking childhood allergic asthma phenotypes with endotype through integrated systems biology: current evidence and research needs

Asthma and other complex diseases results from a complex web of interactions involving inflammation, immunity, cell cycle, apoptosis, and metabolic perturbations across multiple organ systems. The extent to which various degrees of the age at onset, symptom severity, and the natural progression of the disease reflect multiple disease subtypes, influenced by unique process of development remains unknown. One of the most critical challenges to our understanding stems from incomplete understanding of the mechanisms. Within this review, we focus on the phenotypes of childhood allergic asthma as the basis to better understand the endotype for quantitative define subtypes of asthma. We highlight some of the known mechanistic pathways associated with the key hallmark events before the asthma onset. In particular, we examine how the recent advent of multiaxial -omics technologies and systems biology could help to clarify our current understanding of the pathway. We review how a large volume of molecular, genomic data generated by multiaxial technologies could be digested to identify cogent pathophysiologic molecular networks. We highlight some recent successes in application of these technologies within the context of other disease conditions for therapeutic interventions. We conclude by summarizing the research needs for the predictive value of preclinical biomarkers.

Asthma and Hypogammaglobulinemia: an Asthma Phenotype with Low Type 2 Inflammation

PURPOSE

Little is known about hypogammaglobulinemia (HGG) in asthma patients. No data are available on the characteristics of adult patients with asthma and HGG.

METHODS

We conducted a retrospective monocentric study between January 2006 and December 2012. Asthma patients with a serum immunoglobulin (Ig) quantitative analysis were included and classified into two groups depending on their serum IgG concentration: presence or absence of HGG. Clinical, biological, functional, and radiologic characteristics were compared in univariate and multivariate analysis, using a logistic regression model.

RESULTS

In univariate analysis, asthma patients with HGG (n = 25) were older (58 years old ± 18 vs 49 ± 18, p = 0.04) and more frequently active or former smokers as compared to patients with normoglobulinemia (n = 80) (56.0 vs 35.0 %, p = 0.01). Total IgE < 30 kUI/L was more frequently observed in patients with HGG (53.0 vs 18.3 %, p = 0.01). HGG asthma patients had lower fraction of exhaled nitric oxide (p = 0.02), blood eosinophilia (p = 0.0009), and presented with more severe composite score for bronchiectasis (p = 0.01). In multivariate analysis, asthma patients with HGG had increased risk of being smokers [OR = 6.11 (IC 95 % = 1.16-32.04)], having total IgE concentration < 30 kUI/L [OR = 12.87 (IC 95 % = 2.30-72.15)], and a more severe composite score of bronchiectasis [OR = 20.65 (IC 95 % = 2.13-199.74)].

CONCLUSION

Asthma patients with HGG are older and more often tobacco smoker than asthma patients without HGG. These patients have low type-2 inflammation markers.