Significant variability in response to inhaled corticosteroids for persistent asthma

Domiciliary monitoring of exhaled nitric oxide in the management of asthma: a pilot study

BACKGROUND

Whether asthma patients could benefit from home monitoring for fractional exhaled nitric oxide (flow of 50 mL/s, FeNO50) is unknown. We explore the application value of home monitoring FeNO50 in daily asthma management.

METHODS

Twenty-two untreated, uncontrolled asthma patients were selected. Medical history, blood and sputum samples, pulmonary function, Asthma Control Test (ACT), and other clinical data of the subjects were collected. All subjects underwent daily monitoring for four weeks using a FeNO50 monitor and mobile spirometry (mSpirometry). The diurnal differences and dynamic changes were described. Compare the effect-acting time and the relative plateau of treatment between FeNO50 and mSpirometry monitoring.

RESULTS

In the first two weeks, the morning median (IQR) level of FeNO50 was 44 (35, 56) ppb, which was significantly higher than the evening median level [41 (32, 53) ppb, P = 0.028]. The median (IQR) effect-acting time assessed by FeNO50 was 4 (3, 5) days, which was significantly earlier than each measure of mSpirometry (P < 0.05). FeNO50 reached the relative plateau significantly earlier than FEV1 (15 ± 2 days vs. 21 ± 3 days, P < 0.001). After treatment, the daily and weekly variation rates of FeNO50 showed a gradually decreasing trend (P < 0.05). The ACT score, sputum eosinophils, and blood eosinophils also significantly improved (P ≤ 0.01).

CONCLUSIONS

The daily home monitoring of FeNO50 in asthmatic patients showed significant circadian rhythm, and the sensitivity of FeNO50 in evaluating the response to treatment was higher than mSpirometry. The daily and weekly variation rates of FeNO50 change dynamically with time, which may be used to assess the condition of asthma.

Baseline Characteristics and ICS/LAMA/LABA Response in Asthma: Analyses From the CAPTAIN Study

BACKGROUND

Findings from CAPTAIN (NCT02924688) suggest that treatment response to fluticasone furoate/umeclidinium/vilanterol (FF/UMEC/VI) differs according to baseline type 2 inflammation markers in patients with moderate to severe asthma. Understanding how other patient physiologic and clinical characteristics affect response to inhaled therapies may guide physicians toward a personalized approach for asthma management.

OBJECTIVE

To investigate, using CAPTAIN data, the predictive value of key demographic and baseline physiologic variables in patients with asthma (lung function, bronchodilator reversibility, age, age at asthma onset) on response to addition of the long-acting muscarinic antagonist UMEC to inhaled corticosteroid/long-acting β2-agonist combination FF/VI, or doubling the FF dose.

METHODS

Prespecified and post hoc analyses of CAPTAIN data were performed using categorical and continuous variables of key baseline characteristics to understand their influence on treatment outcomes (lung function [trough FEV1], annualized rate of moderate/severe exacerbations, and asthma control [Asthma Control Questionnaire]) following addition of UMEC to FF/VI or doubling the FF dose in FF/VI or FF/UMEC/VI.

RESULTS

Adding UMEC to FF/VI led to greater improvements in trough FEV1 versus doubling the FF dose across all baseline characteristics assessed. Doubling the FF dose was generally associated with numerically greater reductions in the annualized rate of moderate/severe exacerbations compared with adding UMEC, independent of baseline characteristics. Adding UMEC and/or doubling the FF dose generally led to improvements in Asthma Control Questionnaire scores irrespective of baseline characteristics.

CONCLUSIONS

Unlike previous findings with type 2 biomarkers, lung function, bronchodilator reversibility, age and age at asthma onset do not appear to predict response to inhaled therapy.

The efficacy of citalopram or escitalopram in patients with asthma and major depressive disorder

BACKGROUND

Major depressive disorder is common in people with asthma. Yet, few studies have evaluated depression treatment in those with asthma.

OBJECTIVE

To explore the relationship between antidepressant use, depressive symptoms, and asthma control, pooled data from 3 randomized trials of either citalopram or escitalopram were assessed.

METHODS

Linear fixed effects and binary logistic regression analyses were conducted with between-subject covariates including treatment group, (original) study, and demographics. The within-subject effect of visit, and a treatment group-visit (between-within) interaction effect, were also evaluated. Analyses were repeated in a high asthma exacerbation subgroup having at least 3 oral corticosteroid bursts in the previous 12 months. Outcomes included the Hamilton rating scale for depression (HAM-D17), the 7-item asthma control questionnaire (ACQ), and oral corticosteroid use (yes or no).

RESULTS

In the pooled sample (n = 255), the antidepressant treatment group exhibited lower HAM-D17 overall (P ≤ .001) and a lower likelihood for oral corticosteroid use (P ≤ .001) relative to the placebo group. In the high-exacerbation subgroup (n = 96), treatment group participants had lower overall asthma control questionnaire (P = .004) and HAM-D17 scores (P ≤ .001), and a lower likelihood of oral corticosteroid use (P = .003), relative to placebo participants. All treatment group interaction effects were not significant.

CONCLUSION

Citalopram or escitalopram exhibited efficacy in reducing depressive symptoms and the need for rescue oral corticosteroids in patients with asthma and major depressive disorder. Future work should determine whether selective serotonin reuptake inhibitors are effective at improving asthma outcomes in those with asthma who are not depressed.

TRIAL REGISTRATION

Clinicaltrials.gov Identifier: NCT00621946 and NCT01324700 (one study was conducted before ClinicalTrials.gov requirements).

The Saudi initiative for asthma - 2024 update: Guidelines for the diagnosis and management of asthma in adults and children

The Saudi Initiative for Asthma 2024 (SINA-2024) is the sixth version of asthma guidelines for the diagnosis and management of asthma for adults and children that was developed by the SINA group, a subsidiary of the Saudi Thoracic Society. The main objective of the SINA is to have guidelines that are up-to-date, simple to understand, and easy to use by healthcare workers dealing with asthma patients. To facilitate achieving the goals of asthma management, the SINA Panel approach is mainly based on the assessment of symptom control and risk for both adults and children. The approach to asthma management is aligned for age groups: adults, adolescents, children aged 5-12 years, and children aged <5 years. SINA guidelines have focused more on personalized approaches reflecting a better understanding of disease heterogeneity with the integration of recommendations related to biologic agents, evidence-based updates on treatment, and the role of immunotherapy in management. The medication appendix has also been updated with the addition of recent evidence, new indications for existing medication, and new medications. The guidelines are constructed based on the available evidence, local literature, and the current situation at national and regional levels. There is also an emphasis on patient-doctor partnership in the management that also includes a self-management plan.

Rhizoma Dioscoreae Nipponicae Relieves Asthma by Inducing the Ferroptosis of Eosinophils and Inhibiting the p38 MAPK Signaling Pathway

Rhizoma Dioscoreae Nipponicae (RDN) is a traditional Chinese medicine that widely applied in the treatment of human diseases. This study aims to explore the therapeutic potential of RDN in asthma and the underlying mechanisms. A mouse model of asthma was established by the stimulation of ovalbumin (OVA). HE staining was performed to detect the pathological injuries of tracheal tissues. The protein expression of collagen I, FN1, α-SMA (airway remodeling markers), and p-p38 (a marker of the p38 MAPK pathway) were detected by Western blot. Eosinophils were then isolated from the model mice. Cell viability and ROS level were measured by CCK-8 and Flow cytometry, respectively. The mRNA expression of GPX4 and ACSL4 (ferroptosis markers) in eosinophils were measured by qRT-PCR. RDN significantly reduced the numbers of total cells and eosnophils in bronchoalveolar lavage fluid (BALF), inhibited inflammatory cell infiltration, and down-regulated remodeling markers (Collagen I, FN1, and α-SMA) in OVA-induced mice. The p38 MAPK pathway was blocked by the intervention of RDN in the model mice, and its blocking weakens the poor manifestations of OVA-induced asthma. In addition, RDN induced the ferroptosis of eosnophils both in vitro and in vivo. Blocking of the p38 MAPK pathway also enhanced the ferroptosis of eosnophils in vitro, evidenced by the decreased cell viability and GPX4 expression, and increased ROS level and ACSL4 expression. RDN induced the ferroptosis of eosinophils through inhibiting the p38 MAPK pathway, contributing to the remission of asthma.

Dioscorea nipponica Makino: A comprehensive review of its chemical composition and pharmacology on chronic kidney disease

Chronic kidney disease (CKD) is a widespread ailment that significantly impacts global health. It is characterized by high prevalence, poor prognosis, and substantial healthcare costs, making it a major public health concern. The current clinical treatments for CKD are not entirely satisfactory, leading to a high demand for alternative therapeutic options. Chinese herbal medicine, with its long history, diverse varieties, and proven efficacy, offers a promising avenue for exploration. One such Chinese herbal medicine, Dioscorea nipponica Makino (DNM), is frequently used to treat kidney diseases. In this review, we have compiled studies examining the mechanisms of action of DNM in the context of CKD, focusing on five primary areas: improvement of oxidative stress, inhibition of renal fibrosis, regulation of metabolism, reduction of inflammatory response, and regulation of autophagy.

Developments in the Management of Severe Asthma in Children and Adolescents: Focus on Dupilumab and Tezepelumab

Severe asthma in children and adolescents exerts a substantial health, financial, and societal burden. Severe asthma is a heterogeneous condition with multiple clinical phenotypes and underlying inflammatory patterns that might be different in individual patients. Various add-on treatments have been developed to treat severe asthma, including monoclonal antibodies (biologics) targeting inflammatory mediators. Biologics that are currently approved to treat children (≥ 6 years of age) or adolescents (≥ 12 years of age) with severe asthma include: anti-immunoglobulin E (omalizumab), anti-interleukin (IL)-5 (mepolizumab), anti-IL5 receptor (benralizumab), anti-IL4/IL13 receptor (dupilumab), and antithymic stromal lymphopoietin (TSLP) (tezepelumab). However, access to these targeted treatments varies across countries and relies on few and crude indicators. There is a need for better treatment stratification to guide which children might benefit from these treatments. In this narrative review we will assess the most recent developments in the treatment of severe pediatric asthma, as well as potential biomarkers to assess treatment efficacy for this patient population.

Comparison with gastric cancer-associated genes reveals the role of ferroptosis-related genes in eosinophils of asthma patients: A bioinformatic study

Ferroptosis-inducing agents (FIAs) induced lipid-peroxidation-independent ferroptosis in eosinophils, thus ameliorating airway inflammation in asthmatic mice. Differences in ferroptosis-related genes (FerrGs) between eosinophils and cells in which FIAs induce canonical ferroptosis are supposed to contribute to this noncanonical ferroptosis but remain unclear. This study aims to explore these differences. This study used gastric cancer cells (GCCs) in stomach adenocarcinoma as the representative of cells in which FIAs induce canonical ferroptosis. FerrGs in Ferroptosis Database V2 respectively intersected with differentially expressed genes (DEGs) of eosinophils (E-MTAB-4660 dataset) and GCCs (GEPIA2 Stomach adenocarcinoma dataset) to obtain original ferroptosis DEGs (FerrDEGs). Then, they were subjected to Venn analysis to identify FerrDEGs shared by them and FerrDEGs exclusively expressed in eosinophils or GCCs. Identified genes were subjected to functional enrichment analysis, protein-protein interactions analysis, Hub genes analysis, and construction of the LncRNA-mediated ceRNA network. Sixty-six original FerrDEGs in eosinophils and 110 original FerrDEGs in GCCs were obtained. Venn analysis identified that eosinophils and GCCs shared 19 FerrDEGs that presented opposite expression directions and were involved in the ferroptosis pathway. Four upregulated and 20 downregulated FerrDEGs were exclusively expressed in eosinophils and GCCs, respectively. The former were enriched only in glycerolipid metabolism, while the latter were not enriched in pathways. Forty downregulated and 68 upregulated FerrDEGs were solely expressed in eosinophils and GCCs, respectively. The former was associated with the FoxO signaling pathway; the latter was related to glutathione metabolism and they were all implicated in autophagy. PPI analysis shows that the top 10 Hub genes of 66 original FerrDEGs and 44 exclusive FerrDEGs in eosinophils shared 9 genes (STAT3, NFE2L2, MAPK8, PTEN, MAPK3, TLR4, SIRT1, BECN1, and PTGS2) and they were also involved in the FoxO signaling pathway and autophagy pathway. Among them, PTEN is involved in forming a ceRNA network containing 3 LncRNAs, 3 miRNAs and 3 mRNAs. In contrast to FerrGs in cells in which FIAs induce canonical ferroptosis, the FerrGs in eosinophils differ in expression and in the regulation of ferroptosis, FoxO signaling pathway, and autophagy. It lays the groundwork for targeted induction of eosinophils lipid-peroxidation-independent ferroptosis in asthma.

GEMA 5.3. Spanish Guideline on the Management of Asthma

The Spanish Guideline on the Management of Asthma, better known by its acronym in Spanish GEMA, has been available for more than 20 years. Twenty-one scientific societies or related groups both from Spain and internationally have participated in the preparation and development of the updated edition of GEMA, which in fact has been currently positioned as the reference guide on asthma in the Spanish language worldwide. Its objective is to prevent and improve the clinical situation of people with asthma by increasing the knowledge of healthcare professionals involved in their care. Its purpose is to convert scientific evidence into simple and easy-to-follow practical recommendations. Therefore, it is not a monograph that brings together all the scientific knowledge about the disease, but rather a brief document with the essentials, designed to be applied quickly in routine clinical practice. The guidelines are necessarily multidisciplinary, developed to be useful and an indispensable tool for physicians of different specialties, as well as nurses and pharmacists. Probably the most outstanding aspects of the guide are the recommendations to: establish the diagnosis of asthma using a sequential algorithm based on objective diagnostic tests; the follow-up of patients, preferably based on the strategy of achieving and maintaining control of the disease; treatment according to the level of severity of asthma, using six steps from least to greatest need of pharmaceutical drugs, and the treatment algorithm for the indication of biologics in patients with severe uncontrolled asthma based on phenotypes. And now, in addition to that, there is a novelty for easy use and follow-up through a computer application based on the chatbot-type conversational artificial intelligence (ia-GEMA).

Neutrophil extracellular trap production and CCL4L2 expression influence corticosteroid response in asthma

The association between neutrophil extracellular traps (NETs) and response to inhaled corticosteroids (ICS) in asthma is unclear. To better understand this relationship, we analyzed the blood transcriptomes from children with controlled and uncontrolled asthma in the Taiwanese Consortium of Childhood Asthma Study using weighted gene coexpression network analysis and pathway enrichment methods. We identified 298 uncontrolled asthma-specific differentially expressed genes and one gene module associated with neutrophil-mediated immunity, highlighting a potential role for neutrophils in uncontrolled asthma. We also found that NET abundance was associated with nonresponse to ICS in patients. In a neutrophilic airway inflammation murine model, steroid treatment could not suppress neutrophilic inflammation and airway hyperreactivity. However, NET disruption with deoxyribonuclease I (DNase I) efficiently inhibited airway hyperreactivity and inflammation. Using neutrophil-specific transcriptomic profiles, we found that CCL4L2 was associated with ICS nonresponse in asthma, which was validated in human and murine lung tissue. CCL4L2 expression was also negatively correlated with pulmonary function change after ICS treatment. In summary, steroids fail to suppress neutrophilic airway inflammation, highlighting the potential need to use alternative therapies such as leukotriene receptor antagonists or DNase I that target the neutrophil-associated phenotype. Furthermore, these results highlight CCL4L2 as a potential therapeutic target for individuals with asthma refractory to ICS.

The GLCCI1 rs37973 variant and the efficacy of inhaled corticosteroids in the treatment of asthma: A meta-analysis

OBJECTIVE

This study investigated the relationship between the glucocorticoid-induced transcript 1 (GLCCI1) gene variant and the degree of improvement in lung function with inhaled corticosteroids (ICS).

METHODS

We searched the PubMed, Embase, Cochrane Library, CBM, CNKI and Wanfang databases to obtain studies on the GLCCI1 rs37973 variant and the efficacy of ICS in asthma.

RESULTS

The overall meta-analysis showed that patients with the GG phenotype (mutant homozygotes) exhibited significantly smaller forced expiratory volume in 1 sec (FEV1) change than patients with the AG phenotype (mutant heterozygous) (MD = -0.08, 95% CI [-0.12, -0.03], P = 0.001). Compared with the AA phenotype (wild homozygotes), the GG phenotype (MD = -4.23, 95% CI [-6.09, -2.38], P < 0.00001) and AG phenotype (MD = -1.92, 95% CI [-2.35, -1.49], P < 0.00001) had significantly smaller FEV1%pred changes. The FEV1 change subgroup analysis showed that the GG phenotype group was smaller than the AA phenotype group at 8 (MD = -0.53, 95% CI [-0.91, -0.14], P = 0.007), 12 (MD = -0.16, 95% CI [-0.30, -0.02], P = 0.02) and 24 (MD = -0.09, 95% CI [-0.17, -0.01], P = 0.02) weeks of treatment; the GG phenotype group was smaller than the AG phenotype group at 12 weeks (MD = -0.08, 95% CI [-0.15, -0.01], P = 0.02).

CONCLUSION

This meta-analysis suggests that the GLCCI1 rs37973 variant affects the efficacy of ICS and that the presence of the G allele attenuates the improvement in lung function with ICS.

Novel genetic variants associated with inhaled corticosteroid treatment response in older adults with asthma

INTRODUCTION

Older adults have the greatest burden of asthma and poorest outcomes. The pharmacogenetics of inhaled corticosteroid (ICS) treatment response is not well studied in older adults.

METHODS

A genome-wide association study of ICS response was performed in asthmatics of European ancestry in Genetic Epidemiology Research on Adult Health and Aging (GERA) by fitting Cox proportional hazards regression models, followed by validation in the Mass General Brigham (MGB) Biobank and Rotterdam Study. ICS response was measured using two definitions in asthmatics on ICS treatment: (1) absence of oral corticosteroid (OCS) bursts using prescription records and (2) absence of asthma-related exacerbations using diagnosis codes. A fixed-effect meta-analysis was performed for each outcome. The validated single-nucleotide polymorphisms (SNPs) were functionally annotated to standard databases.

RESULTS

In 5710 subjects in GERA, 676 subjects in MGB Biobank, and 465 subjects in the Rotterdam Study, four novel SNPs on chromosome six near PTCHD4 validated across all cohorts and met genome-wide significance on meta-analysis for the OCS burst outcome. In 4541 subjects in GERA and 505 subjects in MGB Biobank, 152 SNPs with p<5 × 10-5 were validated across these two cohorts for the asthma-related exacerbation outcome. The validated SNPs included methylation and expression quantitative trait loci for CPED1, CRADD and DST for the OCS burst outcome and GM2A, SNW1, CACNA1C, DPH1, and RPS10 for the asthma-related exacerbation outcome.

CONCLUSIONS

Multiple novel SNPs associated with ICS response were identified in older adult asthmatics. Several SNPs annotated to genes previously associated with asthma and other airway or allergic diseases, including PTCHD4.

Executive summary: Japanese guidelines for adult asthma (JGL) 2021

Asthma is characterized by chronic airway inflammation, variable airway narrowing, and sensory nerve irritation, which manifest as wheezing, dyspnea, chest tightness, and cough. Longstanding asthma may result in airway remodeling and become intractable. Despite the increased prevalence of asthma in adults, asthma-associated deaths have decreased in Japan (0.94 per 100,000 people in 2020). The goals of asthma treatment include the control of symptoms and reduction of future risks. A functional partnership between physicians and patients is indispensable for achieving these goals. Long-term management with medications and the elimination of triggers and risk factors are fundamental to asthma treatment. Asthma is managed via four steps of pharmacotherapy ("controllers"), ranging from mild to intensive treatments, depending on disease severity; each step involves daily administration of an inhaled corticosteroid, which varies from low to high dosage. Long-acting β₂ agonists, leukotriene receptor antagonists, sustained-release theophylline, and long-acting muscarinic antagonists are recommended as add-on drugs. Allergen immunotherapy is a new option that is employed as a controller treatment. Further, as of 2021, anti-IgE antibody, anti-IL-5 and anti-IL-5 receptor α-chain antibodies, and anti-IL-4 receptor α-chain antibodies are available for the treatment of severe asthma. Bronchial thermoplasty can be performed for asthma treatment, and its long-term efficacy has been reported. Algorithms for their usage have been revised. Comorbidities, such as allergic rhinitis, chronic rhinosinusitis, chronic obstructive pulmonary disease, and aspirin-exacerbated respiratory disease, should also be considered during the treatment of chronic asthma. Depending on the severity of episodes, inhaled short-acting β₂ agonists, systemic corticosteroids, short-acting muscarinic antagonists, oxygen therapy, and other approaches are used as needed ("relievers") during exacerbation.

Asthma Exacerbations in Severe Asthma: Why Systemic Corticosteroids May not Always Be the Best Treatment Option

Purpose

Advances in the management of severe, eosinophilic asthma have improved, but asthma exacerbations continue to occur. This review aims to look at the evidence we have about why exacerbations may occur; their phenotype and why oral corticosteroids may not always be the best treatment option for all exacerbation of symptoms in individuals with severe asthma.

Recent findings

Studies dating back to the 1990s showed that asthma exacerbations across the spectrum of asthma severity were of different inflammatory endotypes. In addition, there is a wealth of evidence suggesting that eosinophilic inflammation is very responsive to corticosteroid therapy, but that non-eosinophilic inflammation is less so. Two recent UK-based studies have undertaken systematic phenotyping of exacerbations in severe asthma and have shown that there are a significant minority of exacerbation events with an increase in asthma symptoms, fall in lung function, but without evidence of raised T2 biomarkers.

Summary

The evidence to date would suggest that T2 biomarker low asthma exacerbations do not benefit from the administration of oral corticosteroids; in fact, the effect of the oral corticosteroids is harmful. However, there is a paucity of data to answer this question directly. Further research is needed to assess the evolution of non-T2 exacerbations not treated with OCS in a randomised, placebo-controlled, manner.

Criteria to evaluate efficacy of biologics in asthma: a Global Asthma Association survey

BACKGROUND

Currently, there are no universally accepted criteria to measure the response to biologics available as treatment for severe asthma. This survey aims to establish consensus criteria to use for the evaluation of response to biologics after 4 months of treatment.

METHOD

Using Delphi methodology, a questionnaire including 10 items was validated by 13 international experts in asthma. The electronic survey circulated within the Interasma Scientific Network platform. For each item, five answers were proposed graduated from 'no importance' to 'very high importance' and by a score (A = 2 points; B = 4 points; C = 6 points; D = 8 points; E = 10 points). The final criteria were selected if the median score for the item was ≥7 and > 60% of responses according 'high importance' and 'very high importance'. All selected criteria were validated by the experts.

RESULTS

Four criteria were identified: reduce daily systemic corticosteroids dose by ≥50%; decrease the number of asthma exacerbations requiring systemic corticosteroids by ≥50%; have no/minimal side effects; and obtain asthma control according validated questionnaires. The consensual decision was that ≥3 criteria define a good response to biologics.

CONCLUSIONS

Specific criteria were defined by an international panel of experts and could be used as tool in clinical practice.

The clinical features of asthma exacerbations in early-onset and eosinophilic late-onset asthma may differ significantly

Over 20 years ago, the concept of asthma control was created and appropriate measurement tools were developed and validated. Loss of asthma control can lead to an exacerbation. Years ago, the term "clinically significant asthma exacerbation" was introduced to define when a loss of control is severe enough to declare it an asthma exacerbation. This term is also used by health insurances to determine when an exacerbation is eligible for reimbursement of biologics in clinical practice, however, it sometimes becomes apparent that a clear separation between loss of "asthma control" and an exacerbation is not always possible. In this review, we attempt to justify why exacerbations in early allergic asthma and adult eosinophilic asthma can differ significantly and why this is important in clinical practice as well as when dealing with health insurers.

Four weeks of repetitive acute hypoxic preconditioning did not alleviate allergen-induced airway dysfunction in rats

Clinical case series suggest beneficial effects of low-dose intermittent hypoxia in asthma. We tested cardiopulmonary effects of repetitive acute hypoxic preconditioning (RAHP) during allergic inflammation. Brown Norway rats were sensitized to house dust mites (HDM) and exposed to 4-week RAHP or normoxia (SHAM), concurrent with weekly HDM or saline (SAL) challenges. We assessed methacholine responses and lung HIF-1α expression at endpoint, and weekly blood pressure (BP). RAHP relative to SHAM: 1) in HDM-challenged rats, showed no protection against HDM-induced airway dysfunction and did not significantly impact BP (week 4 mean BP difference = 10.51 mmHg, p = 0.09) or HIF-1α expression; 2) in SAL-challenged rats, attenuated airway responses to methacholine, reduced BP (week 4 mean BP average difference = -8.72 mmHg, p = 0.04) and amplified HIF-1α expression (p = 0.0086). Four weeks of RAHP did not mitigate the allergen-induced lower airway dysfunction and may detrimentally affect BP. However, it elicited beneficial cardiopulmonary responses in SAL-challenged rats, concurrent with increased HIF-1α expression.

Memory-like innate lymphoid cells in the pathogenesis of asthma

Innate lymphoid cells (ILCs) are recently discovered innate immune cells that reside and self-renew in mucosal tissues and serve as the first line of defense against various external insults. They include natural killer (NK) cells, ILC1s, ILC2s, ILC3s, and lymphoid tissue inducer cells. The development and functions of ILC1-3 reflect those of their adaptive immunity TH1, TH2, and TH17 T-cell counterparts. Asthma is a heterogeneous disease caused by repeated exposure to specific allergens or host/environmental factors (e.g., obesity) that stimulate pathogenic pulmonary immune cells, including ILCs. Memory used to be a hallmark of adaptive immune cells until recent studies of monocytes, macrophages, and NK cells showed that innate immune cells can also exhibit greater responses to re-stimulation and that these more responsive cells can be long-lived. Besides, a series of studies suggest that the tissue-resident innate lymphoid cells have memory-like phenotypes, such as increased cytokine productions or epigenetic modifications following repetitive exposure to allergens. Notably, both clinical and mouse studies of asthma show that various allergens can generate memory-like features in ILC2s. Here, we discuss the biology of ILCs, their roles in asthma pathogenesis, and the evidence supporting ILC memory. We also show evidence suggesting memory ILCs could help drive the phenotypic heterogeneity in asthma. Thus, further research on memory ILCs may be fruitful in terms of developing new therapies for asthma.

What is the added value of FeNO as T2 biomarker?

There is increasing evidence about the role of nitric oxide in type 2 (T2) immune response. Fraction of exhaled nitric oxide (FeNO) is a product of airways inflammation and it is increased in patients with asthma. Since Gustaffson published the first article about this biomarker in the 1990s, interest has continued to grow. Compared with other T2 biomarkers such as blood eosinophil count, induced sputum, or serum periostin, FeNO has some remarkable advantages, including its not invasive nature, easy repeatability, and possibility to be performed even in patients with severe airway obstruction. It is considered as an indicator of T2 inflammation and, by the same token, a useful predictor for inhaled steroid response. It is difficult to determine the utility of nitric oxide (NO) for initial asthma diagnosis. In such a heterogenous disease, a single parameter would probably not be enough to provide a complete picture. There is also an important variability among authors concerning FeNO cutoff values and the percentage of sensibility and specificity for diagnosis. Its high specificity indicates a potential role to “rule in” asthma; however, its lower sensibility could suggest a lower capacity to “rule out” this pathology. For this reason, if a diagnosis of asthma is being considered, FeNO should be considered along with other tests. FeNO has also shown its utility to detect response to steroids, adherence to treatment, and risk of exacerbation. Even though there is not enough quality of evidence to establish overall conclusions, FeNO could be an alternative procedure to diagnose or exclude asthma and also a predictive tool in asthma treated with corticosteroids.

Reduced bronchodilator reversibility correlates with non-type 2 high asthma and future exacerbations: A prospective cohort study

BACKGROUND

Given that airway obstruction in asthma is not always fully reversible, reduced bronchodilator reversibility (BDR) may be a special asthma phenotype.

OBJECTIVE

To explore the characteristics of BDR^high/low phenotypes (defined using two BDR criteria) and their associations with asthma exacerbations (AEs).

METHODS

After baseline assessments, all patients were classified into BDR^high or BDR^low phenotypes. This study consisted of 2 parts. Part I was a 12-month prospective observational cohort study designed to identify the clinical characteristics and associations with future AEs in BDR^high/low phenotypes (n = 456). Part II, designed as a post hoc analysis of the data obtained in Part I, was conducted to assess the association between BDR^high/low phenotypes and treatment responsiveness (n = 360).

RESULTS

Subjects with BDR^low phenotypes had better baseline asthma symptom control and was negatively associated with eosinophilic asthma and type 2 (T2) high asthma. During the 12-month follow-up, those with BDR^low phenotypes had a higher risk of severe AEs (SAEs) (guideline-based criterion: RR_adj = 2.24, 95% CI = [1.25, 3.68]; Ward's criterion: RR_adj = 2.46, 95% CI = [1.40, 4.00]) and moderate-to-severe AEs (MSAEs) (guideline-based criterion: RR_adj = 1.83, 95% CI = [1.22, 2.56]; Ward's criterion: RR_adj = 1.94, 95% CI = [1.32, 2.68]) in the following year according to logistic regression models. Similar findings were obtained with negative binominal regression models. BDR^low phenotype was a risk factor for an insensitive response to anti-asthma treatment (guideline-based criterion: OR_adj = 1.96, 95% CI = [1.05, 3.65]; Ward's criterion: OR_adj = 2.01, 95% CI = [1.12, 3.58]).

CONCLUSION

We identified that BDR^low phenotype was associated with non-T2 high asthma and future AEs. These findings have clinically relevant implications for asthma management.

Can the response to a single dose of beclomethasone dipropionate predict the outcome of long-term treatment in childhood exercise-induced bronchoconstriction?

BACKGROUND

Exercise-induced bronchoconstriction (EIB) is a frequent and highly specific symptom of childhood asthma. Inhaled corticosteroids (ICS) are the mainstay of controller therapy for EIB and asthma; however, a proportion of asthmatic children and adolescents is less responsive to ICS. We hypothesized that a single dose response to ICS could function as a predictor for individual long-term efficacy of ICS.

OBJECTIVE

To assess the predictive value of the bronchoprotective effect of a single-dose beclomethasone dipropionate (BDP) against EIB for the bronchoprotective effect of 4 weeks of treatment, using an exercise challenge test (ECT).

METHODS

Thirty-two steroid-naïve children and adolescents aged 6 to 18 years with EIB were included in this prospective cohort study. They performed an ECT at baseline, after a single-dose BDP (200µg) and after 4 weeks of BDP treatment (100 µg twice daily) to assess EIB severity.

RESULTS

The response to a single-dose BDP on exercise-induced fall in FEV1 showed a significant correlation with the response on exercise-induced fall in FEV1 after 4 weeks of BDP treatment (r = .38, p = .004). A reduction in post-exercise fall in FEV1 of more than 8% after a single-dose BDP could predict BDP efficacy against EIB after 4 weeks of treatment with a positive predictive value of 100% (CI: 86.1-100%) and a negative predictive value of 29.4% (CI: 11.7%-53.7%).

CONCLUSION

We found that the individual response to a single-dose BDP against EIB has a predictive value for the efficacy of long-term treatment with BDP. This could support clinicians in providing personalized management of EIB in childhood asthma.

Principles of asthma treatment and appropriate use of new drugs

Background: Asthma is the most common chronic respiratory disease, affecting 1% to 18% of the population worldwide. It is characterized by various respiratory symptoms, such as wheezing, shortness of breath, chest tightness and cough, and variable airflow limitation. People with asthma often have periods of worsened symptoms and airway obstruction called exacerbations, which can be fatal. We would like to provide the updated clinical management protocols for patients with asthma.Current Concepts: The goal of asthma treatment is to control symptoms adequately and minimize exacerbations. Anti-inflammatory and bronchodilator therapies are the mainstay of asthma treatment and are recommended as a stepwise approach. The pharmacological treatment of asthma involves evaluating and reviewing the current control status based on the symptoms, future risk of exacerbation, comorbidities, side effects, and patient’s satisfaction. Asthma symptoms in some patients remain uncontrolled despite intensive treatment. The development of biomarkers, evaluation of the patient’s phenotype, and personalized treatment, including biologics, can provide new and effective treatment opportunities.Discussion and Conclusion: Successful asthma management can be achieved through accurate diagnosis of asthma, evaluation of the control stages, correct use of controllers and relievers, adjustment of asthma triggers, personalized approach, and training in self-management.

Plasma levels of BAFF and APRIL are elevated in patients with asthma in Saudi Arabia

B-cell activation factor (BAFF) and a proliferation-inducing ligand (APRIL) are members of the tumor necrosis factor superfamily of cytokines and can induce B cell activation, differentiation, and antibody production via interaction with their receptors, including transmembrane activator, calcium modulator, and cyclophilin ligand interactor (TACI), B-cell maturation antigen (BCMA), and B-cell activating factor receptor (BAFF-R). Herein, we assessed the plasma protein levels of BAFF and APRIL in patients with asthma to determine whether their expression is correlated with total IgE production and examined the surface expression of BAFF/APRIL receptors on B cells. Blood samples were collected from 47 patients with controlled asthma symptoms and 20 healthy normal controls, and plasma levels of APRIL, BAFF, and total IgE protein were quantified by corresponding ELISA assays. Furthermore, lymphocytes were isolated and B cells were analyzed for the presence of BAFF-R, BCMA, and TACI receptors using flow cytometry. Our results showed that IgE, BAFF, and APRIL plasma levels were markedly increased in patients with asthma compared with healthy controls. Moreover, expression of BAFF-R and BCMA, but not that of TACI, was significantly increased in patients with asthma compared with healthy controls. Overall, the findings suggest BAFF and APRIL as key mediators of asthma, and determination of their plasma levels may be useful in monitoring asthma symptoms and treatment response.

Use of Fractional Exhaled Nitric Oxide to Guide the Treatment of Asthma: An Official American Thoracic Society Clinical Practice Guideline

Background: The fractional exhaled nitric oxide (FE_NO) test is a point-of-care test that is used in the assessment of asthma.

Objective: To provide evidence-based clinical guidance on whether FE_NO testing is indicated to optimize asthma treatment in patients with asthma in whom treatment is being considered.

Methods: An international, multidisciplinary panel of experts was convened to form a consensus document regarding a single question relevant to the use of FE_NO. The question was selected from three potential questions based on the greatest perceived impact on clinical practice and the unmet need for evidence-based answers related to this question. The panel performed systematic reviews of published randomized controlled trials between 2004 and 2019 and followed the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) evidence-to-decision framework to develop recommendations. All panel members evaluated and approved the recommendations.

Main Results: After considering the overall low quality of the evidence, the panel made a conditional recommendation for FE_NO-based care. In patients with asthma in whom treatment is being considered, we suggest that FE_NO is beneficial and should be used in addition to usual care. This judgment is based on a balance of effects that probably favors the intervention; the moderate costs and availability of resources, which probably favors the intervention; and the perceived acceptability and feasibility of the intervention in daily practice.

Conclusions: Clinicians should consider this recommendation to measure FE_NO in patients with asthma in whom treatment is being considered based on current best available evidence.

Beneficial effects of infrared light-emitting diode in corticosteroid-resistant asthma

Corticosteroid-resistant asthma (CRA) is a severe form of disease and clinically important, since patients do not respond to mainstay corticosteroid therapies. Thus, new therapies are needed. However, a big limiting factor in the understanding of CRA is the existence of different immunological and inflammatory phenotypes, a fact that makes it difficult to reproduce experimentally. Photobiomodulation (PBM) emerges as an alternative therapy based on earlier studies. This study aims to evaluate the effect of PBM using infrared light-emitting diode (ILED) on the development of corticosteroid-resistant asthma. Therefore, groups of rats were sensitized and challenged with ovalbumin plus Freund's adjuvant for the induction of CRA, and treated or not with ILED directly in the respiratory tract on the skin (wavelength 810 nm; power 100 mW; density energy 5 J/cm; total energy 15 J; time 150 s). Our experimental model was capable to induce neutrophilic asthma. Besides that, the corticosteroid treatment did not reverse the lung cell migration as well as the levels of leukotriene B4, and interleukins 17 and 6. The treatment with ILED reduced the lung cell migration; myeloperoxidase activity; mast cell degranulation; and the levels of leukotriene B4, thromboxane B2, prostaglandin E2, tumoral necrosis factor alpha, and interleukins 17 and 6. Still, ILED increased the level of interleukin 10. In conclusion, we showed promisor effects of ILED when irradiated directly in the respiratory tract as adjuvant treatment of corticosteroid-resistant asthma.

Potentiation of long-acting β2-agonist and glucocorticoid responses in human airway epithelial cells by modulation of intracellular cAMP

Introduction

Over 300 million people in the world live with asthma, resulting in 500,000 annual global deaths with future increases expected. It is estimated that around 50–80% of asthma exacerbations are due to viral infections. Currently, a combination of long-acting beta agonists (LABA) for bronchodilation and glucocorticoids (GCS) to control lung inflammation represent the dominant strategy for the management of asthma, however, it is still sub-optimal in 35–50% of moderate-severe asthmatics resulting in persistent lung inflammation, impairment of lung function, and risk of mortality. Mechanistically, LABA/GCS combination therapy results in synergistic efficacy mediated by intracellular cyclic adenosine monophosphate (cAMP).

Hypothesis

Increasing intracellular cAMP during LABA/GCS combination therapy via inhibiting phosphodiesterase 4 (PDE4) and/or blocking the export of cAMP by ATP Binding Cassette Transporter C4 (ABCC4), will potentiate anti-inflammatory responses of mainstay LABA/GCS therapy.

Methods

Expression and localization experiments were performed using in situ hybridization and immunohistochemistry in human lung tissue from healthy subjects, while confirmatory transcript and protein expression analyses were performed in primary human airway epithelial cells and cell lines. Intervention experiments were performed on the human airway epithelial cell line, HBEC-6KT, by pre-treatment with combinations of LABA/GCS with PDE4 and/or ABCC4 inhibitors followed by Poly I:C or imiquimod challenge as a model for viral stimuli. Cytokine readouts for IL-6, IL-8, CXCL10/IP-10, and CCL5/RANTES were quantified by ELISA.

Results

Using archived human lung and human airway epithelial cells, ABCC4 gene and protein expression were confirmed in vitro and in situ. LABA/GCS attenuation of Poly I:C or imiquimod-induced IL-6 and IL-8 were potentiated with ABCC4 and PDE4 inhibition, which was greater when ABCC4 and PDE4 inhibition was combined. Modulation of cAMP levels had no impact on LABA/GCS modulation of Poly I:C-induced CXCL10/IP-10 or CCL5/RANTES.

Conclusion

Modulation of intracellular cAMP levels by PDE4 or ABCC4 inhibition potentiates LABA/GCS efficacy in human airway epithelial cells challenged with viral stimuli. The data suggest further exploration of the value of adding cAMP modulators to mainstay LABA/GCS therapy in asthma for potentiated anti-inflammatory efficacy.

Using FeNO Measurement in Clinical Asthma Management

Asthma is a common and heterogeneous disease, characterised by lower airway inflammation and airflow limitation. Critical factors in asthma management include establishing an accurate diagnosis and ensuring appropriate selection and dosage of anti-inflammatory therapies. The majority of asthma patients exhibit type 2 (T2) inflammation, with increased interleukin (IL)-4, IL-5, and IL-13 signalling, often with associated eosinophilia. Identifying lower airway eosinophilia with sputum induction improves asthma outcomes, but is time consuming and costly. Increased T2-inflammation leads to upregulation of nitric oxide (NO) release into the airway, with increasing fractional exhaled NO (FeNO) reflecting greater T2-inflammation. FeNO can be easily and quickly measured in the clinic, offering a point of care surrogate measure of the degree of lower airway inflammation. FeNO testing can be used to help confirm an asthma diagnosis, to guide inhaled corticosteroid therapy, to assess adherence to treatment, and to aid selection of appropriate biologic therapy. However, FeNO levels may also be influenced by a variety of intrinsic and extrinsic factors other than asthma, including nasal polyposis and cigarette smoking, and must be interpreted in the broader clinical context rather than viewed in isolation. This review discusses the clinical application of FeNO measurement in asthma care, from diagnosis to treatment selection, and describes its place in current international expert guidelines.

Identification of ROBO2 as a Potential Locus Associated with Inhaled Corticosteroid Response in Childhood Asthma

Inhaled corticosteroids (ICS) are the most common asthma controller medication. An important contribution of genetic factors in ICS response has been evidenced. Here, we aimed to identify novel genetic markers involved in ICS response in asthma. A genome-wide association study (GWAS) of the change in lung function after 6 weeks of ICS treatment was performed in 166 asthma patients from the SLOVENIA study. Patients with an improvement in lung function ≥8% were considered as ICS responders. Suggestively associated variants (p-value ≤ 5 × 10⁻⁶) were evaluated in an independent study (n = 175). Validation of the association with asthma exacerbations despite ICS use was attempted in European (n = 2681) and admixed (n = 1347) populations. Variants previously associated with ICS response were also assessed for replication. As a result, the SNP rs1166980 from the ROBO2 gene was suggestively associated with the change in lung function (OR for G allele: 7.01, 95% CI: 3.29–14.93, p = 4.61 × 10⁻⁷), although this was not validated in CAMP. ROBO2 showed gene-level evidence of replication with asthma exacerbations despite ICS use in Europeans (minimum p-value = 1.44 × 10⁻⁵), but not in admixed individuals. The association of PDE10A-T with ICS response described by a previous study was validated. This study suggests that ROBO2 could be a potential novel locus for ICS response in Europeans.

Direct and indirect bronchoprovocation tests in dose-response studies of inhaled corticosteroids: Past, present, and future directions

Inhaled corticosteroids (ICS) are a mainstay of treatment in eosinophilic asthma. Many studies have explored the dose-response effect of different formulations of ICS through direct or indirect bronchoprovocation testing. Such studies are important for investigating efficacy and identifying the relative potency between formulations. However, lack of consistency in methods and designs has hindered the comparability of study findings. This review discusses current knowledge of the dose-response, or lack thereof, of different formulations of ICS through direct and indirect bronchoprovocation testing. The strengths and weaknesses of past studies inform recommendations for future methodological considerations in this field, such as utilizing a randomized double-blind crossover design, enrolling participants likely to respond to ICS therapy, and carefully selecting treatment durations and washout periods to assess incremental improvement in airway hyperresponsiveness while reducing the likelihood of a carryover effect.

Establishing a patient registry study database of dust mite allergic asthma in children: design, methodology and preliminary exploration

Background

Asthma is a heterogeneous disease with different phenotypes, endotypes and responses to treatment. Dust mite allergic asthma (DMAA) is the most common type in children. Compared with randomized control trials, a patient registry study (PRS) can reflect the real physical condition and clinical diagnosis more comprehensively.

Methods

Children who visited the asthma clinic of the Children’s Hospital of Chongqing Medical University between August 2018 and August 2020, and met the inclusion criteria and also agreed to participate, were enrolled in the registry study. Clinical information, laboratory tests and peripheral blood samples were collected after informed consent was given by guardians.

Results

To date, 208 children have been enrolled in the patient registry database of DMAA. They are mainly male, with >50% having a history of allergic rhinitis, cesarean section, positive family history and passive smoking. Eosinophils and total immunoglobulin E levels were all significantly higher than normal. According to results for the childhood asthma control test (c-ACT) and ratio of forced expiratory volume in 1 s to predicted value after inhaled corticosteroid treatment, the uncontrolled group had higher hemoglobin (Hb) levels than the control group. The group exhibiting abnormal pulmonary function was older, and had longer disease duration, higher fractional exhaled nitric oxide and Hb than the group in which pulmonary function was restored.

Conclusions

We have preliminarily established a registered study database of children with DMAA. By cluster analysis and using blood samples, we can further study the different pathophysiological mechanisms in order to provide more individualized and targeted treatments for all children.

High fractional exhaled nitric oxide levels in asthma patients: Does size matter?

BACKGROUND

Fractional exhaled nitric oxide (FeNO) is a biomarker for eosinophilic inflammation used for diagnosis and monitoring of asthma. High FeNO indicates significant airway eosinophilia and steroid-responsive airway inflammation. Some children with asthma have extremely high FeNO levels, but whether these levels represent a different asthma phenotype compared with those with mildly elevated FeNO is unclear. The objective of this study is to investigate whether the extent of high FeNO levels correlates with clinical phenotype, asthma control, comorbidity, and pulmonary function test (PFT) findings in children with asthma.

METHODS

Anthropometric data, daytime and nighttime symptoms, controller treatment, comorbidity, and PFT findings were retrieved from the Pediatric Pulmonology Unit database (2014-2020) and correlated with FeNO levels in pediatric asthma patients with high FeNO levels.

RESULTS

Two-hundred children and adolescents with high FeNO levels (range 36-227 ppb) were included. Within this range, higher FeNO levels positively correlated with increased daytime and nighttime symptoms (p = .013 and p = .01, respectively) and poorly controlled asthma (p = .034). A FeNO level of ≥80 ppb was the cutoff for significantly more severe daytime and nighttime symptoms and very poorly controlled asthma compared with levels <80 ppb (p = .004, p = .005, and p = .036, respectively). No correlation was found between FeNO and controller treatment, comorbidity, and PFT performance.

CONCLUSION

In pediatric asthma patients, high FeNO levels correlate with increased symptom severity and poor asthma control. A FeNO level of ≥80 ppb may serve as an objective indicator for severe asthma.

A low exhaled nitric oxide level excludes a short-term benefit from inhaled corticosteroids in suspected asthma: A randomized placebo-controlled trial

BACKGROUND AND OBJECTIVE

Fractional exhaled nitric oxide (FeNO) is a non-invasive biomarker that reflects IL-4/IL-13 production and therefore represents T2 allergic inflammation. FeNO has previously been used to guide inhaled corticosteroid (ICS) treatment in asthma. The purpose of this study was to determine if a low FeNO (≤27 ppb) could be used to reliably identify patients with symptoms suggestive of asthma who would not benefit from initiating treatment with an ICS.

METHODS

A total of 180 steroid-naïve adults with healthcare professional suspected asthma and an FeNO of ≤27 ppb were randomized to receive either 400 mcg of budesonide or placebo daily for 3 months. The primary outcome was the difference in the Asthma Control Questionnaire 7 (ACQ7) between treatment groups and the study was powered to determine equivalence. Secondary outcomes were the difference in FEV₁ , Medical Research Council and Leicester Cough Questionnaire scores.

RESULTS

One hundred and thirty-four patients (68 budesonide and 66 placebo) completed the study and were included in the analysis. The between-group mean difference in ACQ7 from baseline to the end of the study was -0.25 and the 95% CI around this difference was -0.004 to 0.495 confirming equivalence (p < 0.05). Differences in forced expiratory volume over 1 s and other secondary outcomes were also small and clinically unimportant.

CONCLUSION

The results of this study suggest that steroid-naïve patients with symptoms suggestive of asthma and an FeNO ≤ 27 ppb are unlikely to benefit from initiating treatment with an ICS over 3 months. However, further research is recommended to confirm these findings before withholding ICS treatment.

Drug Repurposing to Treat Glucocorticoid Resistance in Asthma

Corticosteroid resistance causes significant morbidity in asthma, and drug repurposing may identify timely and cost-effective adjunctive treatments for corticosteroid resistance. In 95 subjects from the Childhood Asthma Management Program (CAMP) and 19 subjects from the Severe Asthma Research Program (SARP), corticosteroid response was measured by the change in percent predicted forced expiratory volume in one second (FEV₁). In each cohort, differential gene expression analysis was performed comparing poor (resistant) responders, defined as those with zero to negative change in FEV₁, to good responders, followed by Connectivity Map (CMap) analysis to identify inversely associated (i.e., negatively connected) drugs that reversed the gene expression profile of poor responders to resemble that of good responders. Mean connectivity scores weighted by sample size were calculated. The top five drug compound candidates underwent in vitro validation in NF-κB-based luciferase reporter A549 cells stimulated by IL-1β ± dexamethasone. In CAMP and SARP, 134 and 178 respective genes were differentially expressed in poor responders. CMap analysis identified 46 compounds in common across both cohorts with connectivity scores < −50. γ-linolenic acid, ampicillin, exemestane, brinzolamide, and INCA-6 were selected for functional validation. γ-linolenic acid, brinzolamide, and INCA-6 significantly reduced IL-1β induced luciferase activity and potentiated the anti-inflammatory effect of dexamethasone in A549/NF-κB-luc reporter cells. These results demonstrate how existing drugs, including γ-linolenic acid, brinzolamide, and INCA-6, may be repurposed to improve corticosteroid response in asthmatics.

Eosinophils and childhood asthma

Eosinophils are a type of granulocyte with eosinophilic granules in the cytoplasm that play an important role in allergic and parasitic diseases. Eosinophils are important in the pathogenesis of asthma, and many studies have examined the relationship between them. In allergic eosinophilic asthma, eosinophils act not only as important effector cells but also as antigen-presenting cells in allergic inflammatory reactions. In nonallergic eosinophilic asthma, type 2 innate lymphoid cells in the airways play an important role in eosinophil activation. Direct methods, including bronchial biopsy, bronchoalveolar lavage, and the induced sputum test, are used to evaluate eosinophilic inflammatory reactions in patients with asthma, however, because of difficulty with their implementation, they are sometimes replaced by measurements of blood eosinophils, fraction of exhaled nitric oxide, and serum periostin level. However, these tests are less accurate than direct methods. For the treatment of patients with severe eosinophilic asthma, anti-interleukin-5 preparations such as mepolizumab, reslizumab, and benralizumab have recently been introduced and broadened the scope of asthma treatment. Although eosinophils are already known to play an important role in asthma, we expect that further studies will reveal more details of their action.

An update on the epigenetics of asthma

PURPOSE OF REVIEW

Asthma is a common disease worldwide, however, its pathogenesis has not been fully elucidated. Emerging evidence suggests that epigenetic modifications may play a role in the development and natural history of asthma. The aim of this review is to highlight recent progress in research on epigenetic mechanisms in asthma.

RECENT FINDINGS

Over the past years, epigenetic studies, in particular DNA methylation studies, have added to the growing body of evidence supporting a link between epigenetic regulation of gene expression and asthma. Recent studies demonstrate that epigenetic mechanisms also play a role in asthma remission. Although most existing studies in this field have been conducted on blood cells, recent evidence suggests that epigenetic signatures are also crucial for the regulation of airway epithelial cells. Studies conducted on nasal epithelium revealed highly replicable epigenetic patterns that could be used for diagnostic purposes.

SUMMARY

Further research is needed to explore the diagnostic and therapeutic potential of epigenetic modifications in asthma. Multiomics studies on asthma will become increasingly important for a better understanding of etiology, heterogeneity, and severity of asthma, as well as establishing molecular biomarkers that could be combined with clinical information to improve the management of asthma patients.

Pharmacogenetics of inhaled corticosteroids and exacerbation risk in adults with asthma

BACKGROUND

Inhaled corticosteroids (ICS) are a cornerstone of asthma treatment. However, their efficacy is characterized by wide variability in individual responses.

OBJECTIVE

We investigated the association between genetic variants and risk of exacerbations in adults with asthma and how this association is affected by ICS treatment.

METHODS

We investigated the pharmacogenetic effect of 10 single nucleotide polymorphisms (SNPs) selected from the literature, including SNPs previously associated with response to ICS (assessed by change in lung function or exacerbations) and novel asthma risk alleles involved in inflammatory pathways, within all adults with asthma from the Dutch population-based Rotterdam study with replication in the American GERA cohort. The interaction effects of the SNPs with ICS on the incidence of asthma exacerbations were assessed using hurdle models adjusting for age, sex, BMI, smoking and treatment step according to the GINA guidelines. Haplotype analyses were also conducted for the SNPs located on the same chromosome.

RESULTS

rs242941 (CRHR1) homozygotes for the minor allele (A) showed a significant, replicated increased risk for frequent exacerbations (RR = 6.11, P < 0.005). In contrast, rs1134481 T allele within TBXT (chromosome 6, member of a family associated with embryonic lung development) showed better response with ICS. rs37973 G allele (GLCCI1) showed a significantly poorer response on ICS within the discovery cohort, which was also significant but in the opposite direction in the replication cohort.

CONCLUSION

rs242941 in CRHR1 was associated with poor ICS response. Conversely, TBXT variants were associated with improved ICS response. These associations may reveal specific endotypes, potentially allowing prediction of exacerbation risk and ICS response.

Asthma in Competitive Cross-Country Skiers: A Systematic Review and Meta-analysis

INTRODUCTION

In cross-country skiing, the repetitive ventilation of large amounts of cold and dry air strains the airways. The aim of this systematic review was to establish an overview of the current literature on asthma in cross-country skiers, biathletes and ski-orienteers.

METHODS

Six databases were searched on August 29, 2019. The search yielded 2161 articles. Thirty articles fulfilled the search criteria and were pooled together for a qualitative synthesis. Eight articles were included in the meta-analysis on the prevalence of asthma and the use of asthma medication.

RESULTS

According to the meta-analysis, the prevalence of self-reported physician-diagnosed asthma in skiers was 21% (95% CI 14-28%). The onset age of asthma was higher in skiers than in non-skiers with asthma. The prevalence of asthma medication use was on average 23% (CI 95% 19-26%). Several studies reported that asthma was underdiagnosed in skiers, as previously healthy skiers without a prior asthma diagnosis or medication use were frequently found to fulfill diagnostic criteria for asthma according to lung function tests. Studies using bronchial biopsy demonstrated that eosinophilic asthma is not detected in skiers with asthma as often as it is in non-skiers with asthma and that there are signs of airway inflammation even in non-asthmatic skiers.

CONCLUSION

Our findings suggest that the accuracy and coverage of diagnosing asthma in skiers has improved over the recent decades. However, the optimal treatment and natural course of asthma in this population remain unclear. Future research should investigate how the intensity of training, airway infections and their treatment affect the development of asthma among skiers.

PRD REGISTRATION NUMBER

CRD42017070940.

Japanese guidelines for adult asthma 2020

Bronchial asthma is characterized by chronic airway inflammation, which manifests clinically as variable airway narrowing (wheezes and dyspnea) and cough. Long-standing asthma may induce airway remodeling and become intractable. The prevalence of asthma has increased; however, the number of patients who die from it has decreased (1.3 per 100,000 patients in 2018). The goal of asthma treatment is to control symptoms and prevent future risks. A good partnership between physicians and patients is indispensable for effective treatment. Long-term management with therapeutic agents and the elimination of the triggers and risk factors of asthma are fundamental to its treatment. Asthma is managed by four steps of pharmacotherapy, ranging from mild to intensive treatments, depending on the severity of disease; each step includes an appropriate daily dose of an inhaled corticosteroid, which may vary from low to high. Long-acting β₂-agonists, leukotriene receptor antagonists, sustained-release theophylline, and long-acting muscarinic antagonists are recommended as add-on drugs, while anti-immunoglobulin E antibodies and other biologics, and oral steroids are reserved for very severe and persistent asthma related to allergic reactions. Bronchial thermoplasty has recently been developed for severe, persistent asthma, but its long-term efficacy is not known. Inhaled β₂-agonists, aminophylline, corticosteroids, adrenaline, oxygen therapy, and other approaches are used as needed during acute exacerbations, by selecting treatment steps for asthma based on the severity of the exacerbations. Allergic rhinitis, eosinophilic chronic rhinosinusitis, eosinophilic otitis, chronic obstructive pulmonary disease, aspirin-exacerbated respiratory disease, and pregnancy are also important conditions to be considered in asthma therapy.

Aryl hydrocarbon receptor deficiency enhanced airway inflammation and remodeling in a murine chronic asthma model

The aryl hydrocarbon receptor (AhR) is a ligand-dependent-activated transcriptional factor that regulates the metabolism of xenobiotic and endogenous compounds. Recent studies have shown that AhR is a novel master regulator of the mucosal immune system, including lungs and intestine. To elucidate the role of AhR in chronic severe asthma, AhR wild-type and knockout mice (AhR^-/- ) were sensitized and challenged with ovalbumin for 4 weeks. To uncover the underlying mechanisms, inflammatory cells profile and cytokines production were analyzed in bronchial lavage fluid (BALF) and lung tissue. Compared to wild-type mice, AhR^-/- mice had exacerbated asthma symptoms, including airway inflammation, mucus production, airway hyperresponsiveness, and airway remodeling. BALF monocytes, neutrophils, eosinophils, and lymphocytes were all enhanced in OVA-immunized AhR^-/- mice. In OVA-immunized AhR^-/- mice, T helper (Th) 17 cell-specific cytokine IL-17A, as well as airway remodeling factors, including epithelial-mesenchymal transition (EMT) markers and vascular endothelial growth factor (VEGF), were all enhanced in lung tissue. Moreover, human cohort studies showed that AhR gene expression in bronchial epithelial cells decreases in severe asthma patients. Loss of AhR leads to worsening of allergic asthma symptoms, indicating its importance in maintaining normal lung function and mediating disease severity.

The beneficial role of FeNO in association with GINA guidelines for titration of inhaled corticosteroids in adult asthma: A randomized study

PURPOSE

This study aimed to demonstrate the role of fractional concentration of exhaled nitric oxide (FeNO) in association with Global Initiative for Asthma (GINA) guidelines for treatment of adult patients with asthma.

METHODS

It was a prospective and randomized study. The symptomatic asthmatic patients were randomly divided into two groups: GINA group (followed GINA guidelines; N = 86) or GINA + FeNO group (followed GINA guidelines + FeNO for titration of inhaled corticosteroids - ICS; N = 90). They were followed-up for 9 months.

RESULTS

In GINA group, 37.2% patients had no treatment and 62.8% patients discontinued treatment vs. 40.0% and 60.0% in GINA + FeNO, respectively. After 3, 6 and 9 months of treatment, the percentage of mild, moderate and severe asthma showed no significant difference between the two groups. At 9th month, Δ moderate asthma (reduction) in GINA + FeNO group was significantly higher than in the GINA group (-22.0% vs. -11.6%; P = 0.018). The improvement of asthma control test (ACT) score was not different between the groups at 9th month (12 ± 6 vs. 10 ± 5; P > 0.05); the level of FeNO reduction in GINA + FeNO group was significantly higher than that in GINA group (-42 ± 11 vs. -35 ± 9; P = 0.022). The daily dose of ICS in GINA + FeNO group was significantly lower than that in GINA group (397 ± 171 vs. 482 ± 240 mcg and 375 ± 203 vs. 424 ± 221 mcg; respectively) at the end of 6 and 9 months.

CONCLUSION

The use of FeNO in association with GINA guidelines has a beneficial role for accurate daily dose of ICS in adult patients with asthma.

Induction of ferroptosis-like cell death of eosinophils exerts synergistic effects with glucocorticoids in allergic airway inflammation

INTRODUCTION

Eosinophils are critical in allergic disorders, and promoting eosinophil death effectively attenuates allergic airway inflammation. Ferroptosis is a recently described novel form of cell death; however, little is known about ferroptosis in eosinophils and related diseases. This study aimed to investigate the effects of ferroptosis-inducing agents (FINs) on eosinophil death and allergic airway inflammation, and to explore their potential synergistic effect with glucocorticoids (GCs).

METHODS

Eosinophils isolated from the peripheral blood of humans or mice were incubated with FINs, and eosinophil ferroptosis was assessed. The in vivo effects of FINs alone or in combination with dexamethasone (DXMS) were examined in a mouse model of allergic airway inflammation. Bronchoalveolar lavage fluid and lung tissue were collected to examine airway inflammation.

RESULTS

Treatment with FINs time and dose dependency induced cell death in human and mouse eosinophils. Interestingly, FINs induced non-canonical ferroptosis in eosinophils, which generated morphological characteristics unique to ferroptosis and was iron dependent but was independent of lipid peroxidation. The antioxidants glutathione and N-acetylcysteine significantly attenuated FIN-induced cell death. Treatment with FINs triggered eosinophil death in vivo and eventually relieved eosinophilic airway inflammation in mice. Furthermore, FINs exerted a synergistic effect with DXMS to induce eosinophil death in vitro and to alleviate allergic airway inflammation in vivo.

CONCLUSIONS

FINs induced ferroptosis-like cell death of eosinophils, suggesting their use as a promising therapeutic strategy for eosinophilic airway inflammation, especially due to the advantage of their synergy with GCs in the treatment of allergic disorders.

Identification of Specific IgE Antibodies and Asthma Control Interaction and Association Using Cluster Analysis in a Bulgarian Asthmatic Children Cohort

(1) Background: Asthma is a complex heterogeneous disease that likely comprises several distinct disease phenotypes, where the clustering approach has been used to classify the heterogeneous asthma population into distinct phenotypes; (2) Methods: For a period of 1 year, we evaluated medical history data of 71 children with asthma aged 3 to 17 years, performing pulmonary function tests, drew blood for IgE antibodies against inhalation and food allergies detection, and Asthma Control Questionnaire (ACQ); (3) Results: Five distinct phenotypes were determined. Cluster 1 (n = 10): (non-atopic) the lowest IgE level, very low ACQ, and median age of diagnosis. Cluster 2 (n = 28): (mixed) the highest Body mass index (BMI) with the latest age of diagnosis and high ACQ and bronchodilator response (BDR) levels and median and IgE levels. Cluster 3 (n = 19) (atopic) early diagnosis, highest BDR, highest ACQ score, highest total, and high specific IgE levels among the clusters. Cluster 4 (n = 9): (atopic) the highest specific IgE result, relatively high BMI, and IgE with median ACQ score among clusters. Cluster 5 (n = 5): (non-atopic) the earliest age for diagnosis, with the lowest BMI, the lowest ACQ score, and specific IgE levels, with high BDR and the median level of IgE among clusters; (4) Conclusions: We identified asthma phenotypes in Bulgarian children according to IgE levels, ACQ score, BDR, and age of diagnosis.

Circulating MicroRNAs and Treatment Response in Childhood Asthma

Rationale: Inhaled corticosteroids (ICS) are key treatments for controlling asthma and preventing asthma attacks. However, the responsiveness to ICS varies among individuals. MicroRNAs (miRNAs) have been lauded for their prognostic utility.Objectives: We hypothesized that circulating miRNAs obtained at baseline/prerandomization in the Childhood Asthma Management Program (CAMP) could serve as biomarkers and biologic mediators of ICS clinical response over the 4-year clinical trial period.Methods: We selected baseline serum samples from 462 CAMP subjects subsequently randomized to either ICS (budesonide) or placebo. Samples underwent small RNA sequencing, and read counts were normalized and filtered by depth and coverage. Linear regression was used to associate miRNAs with change in FEV1% (prebronchodilator FEV1 as a percent predicted) over the 4-year treatment period in both main effects and interaction models. We validated the function of the top associated miRNAs by luciferase reporter assays of glucocorticoid-mediated transrepression and predicted response to ICS through logistic regression models.Measurements and Main Results: We identified 7 miRNAs significantly associated with FEV1% change (P ≤ 0.05) and 15 miRNAs with significant interaction (P ≤ 0.05) to ICS versus placebo treatments. We selected three miRNAs for functional validation, of which hsa-miR-155-5p and hsa-miR-532-5p were significantly associated with changes in dexamethasone-induced transrepression of NF-κB. Combined, these two miRNAs were predictive of ICS response over the course of the clinical trial, with an area under the receiver operating characteristic curve of 0.86.Conclusions: We identified two functional circulating miRNAs predictive of asthma ICS treatment response over time.

Gene polymorphisms in VEGFA and COL2A1 are associated with response to inhaled corticosteroids in children with asthma

Aim: The purpose of this study was to investigate the involvement of single-nucleotide polymorphisms in VEGFA, TBX21 and COL2A1 in the response to inhaled corticosteroids in asthmatic children. Subjects & methods: Children with mild-to-moderate asthma were enrolled in the study. The SEQUENOM MassARRAY method was used to sequence 27 SNP genotypes. By ranking the data from smallest to largest, we could infer whether the change in distribution of forced expiratory volume in one second/forced vital capcacity (FEV₁/FVC) and fractional exhaled nitric oxide differed between genotype groups. Results: VEGFA rs3025039 T allele carriers had a smaller change in FEV₁ than CC carriers (p = 0.040), and in COL2A1 rs3809324, the frequency of T allele carriers was lower than that of GG carriers (p = 0.048). rs3025039 was also associated with changes in FEV₁/FVC (p = 0.016). Conclusion: VEGFA and COL2A1 polymorphisms are significantly associated with the response to inhaled corticosteroids in asthmatic children.

Predictors of response to medications for asthma in pediatric patients: A systematic review of the literature

OBJECTIVES

There has been no systematic review of studies aimed to predict differential responses to medication regimens for asthma controller therapies in pediatric patients. The aim of the present study was to summarize those identifying biomarkers for the different asthma controller therapies.

METHODS

Studies published by June 2019 that report phenotypic or genotypic characteristics or biomarkers that could potentially serve as response predictors to asthma controller therapies in pediatric patients were included. The quality of studies was assessed using the Cochrane Risk of Bias tool and the Newcastle-Ottawa Scale tool.

RESULTS

Of 385 trials identified, 30 studies were included. Children with asthma and a positive family history of asthma, with more severe disease, of the white race, with allergy biomarkers, nonobese, with lower lung function, high bronchial hyperresponsiveness to methacholine, or having variants in the FCER2 and CRHR1 gene respond better to inhaled corticosteroids (ICS). Younger age (<10 years), short disease duration (<4 years), high cotinine and urinary leukotriene E4 (LTE4) levels, and 5/5 ALOX5 were associated with a better response to leukotriene receptor antagonist (LTRA). For patients that remain symptomatic, white Hispanics were more likely to respond to LTRA, blacks to ICS, white non-Hispanics to LTRA or LABA, and children without a history of eczema, regardless of race or ethnicity to LABA set-up therapy. In severe persistent asthma, those with atopy and body mass index greater than or equal 25 were more likely to benefit from omalizumab.

CONCLUSION

Several phenotypic characteristics, biomarkers, or pharmacogenomics markers could be useful for predicting the best drug for asthma treatment.

Evaluation of C-C Chemokine Ligand 5 (CCL5) Chemokine, Interleukin 5 (IL-5) Cytokine, and Eosinophil Counts as Potential Biomarkers in Saudi Patients with Chronic Asthma During Sandstorms

Background and objectives

Asthma is a common chronic inflammatory disorder of the lung that can be exacerbated by environmental triggers during sandstorms. This study aimed to evaluate the usefulness of C-C chemokine ligand 5 (CCL5) chemokine and interleukin 5 (IL-5) cytokine and determine the total eosinophil count in blood and sputum for use as biomarkers in Saudi patients with chronic asthma who visited emergency departments during sandstorms.

Methods

The study included 42 Saudi patients with chronic asthma and 20 healthy controls. Plasma levels of CCL5, IL-5, and total immunoglobulin E (IgE) were measured using a specific enzyme-linked immunosorbent assay (ELISA). Total eosinophils in peripheral blood were counted using a hematology analyzer (CELL-DYN Ruby System; Abbott Diagnostics, Chicago, Illinois); in sputum, eosinophils stained with Giemsa were examined under a microscope, counted, and expressed as a percentage of the total cells.

Results

Total IgE levels were significantly higher in patients with asthma (mean 433 IU/ml, P = 0.0001) as compared to normal controls (139 IU/ml). There was no significant difference in the levels of CCL5 in patients with asthma (625 pg/ml) as compared to normal controls (663 pg/ml, P = 0. 57). No correlation was found between total IgE and CCL5 levels. IL-5 was not detected in patients with asthma or in controls. Moreover, the total counts of eosinophils in the blood did not increase in patients with asthma as compared to controls while eosinophils in sputum samples were increased in the former (mean =3.128%).

Conclusion

Plasma levels of CCL5 and IL-5 or eosinophil counts in the peripheral blood may not be useful diagnostic biomarkers to evaluate airway inflammation and monitor asthma severity. Conversely, the sputum eosinophil count may represent a useful diagnostic marker for assessing the magnitude of asthma exacerbation during sandstorms.

DNA methylation is associated with improvement in lung function on inhaled corticosteroids in pediatric asthmatics

Asthma is the most common chronic disease in children. Inhaled corticosteroids (ICS) are the first-line treatment for asthma control, but up to one-third of children have a poor treatment response. The mechanism of ICS resistance is poorly understood, and the role of DNA methylation in ICS treatment response is not known. We examined the association between peripheral blood DNA methylation and ICS treatment response in 152 pediatric persistent asthmatics from the Childhood Asthma Management Program. Response to ICS was measured by the percentage change in forced expiratory volume in 1 s (FEV1) 8 weeks after treatment initiation. The top CpG sites with a nominal P value less than 0.001 were correlated with gene expression using Pearson's and partial correlations. In 152 participants, mean±SD age was 9.8±2.0 years and median change in FEV1 after ICS initiation was 4.6% (interquartile range: 10.4%). A total of 545 CpG sites were differentially methylated (nominal P<0.05), and seven CpG sites had a nominal P value less than 0.001. Relative hypermethylation of cg20434811, cg02822723, cg14066280, cg27254601, and cg23913400 and relative hypomethylation of cg24937126 and cg24711626 were associated with an increase in FEV1 on ICS treatment. One CpG site was associated with gene expression. Relative hypermethylation of cg27254601 was associated with both an increase in FEV1 and BOLA2 expression (ρ=0.25, P=0.02). We identified a novel association between BOLA2 methylation, gene expression, and ICS response as measured by lung function. Pharmacoepigenetics has the potential to detect treatment sensitivity in persistent childhood asthma.