Determining asthma treatment by monitoring sputum cell counts: effect on exacerbations

Eosinophils-from cradle to grave: An EAACI task force paper on new molecular insights and clinical functions of eosinophils and the clinical effects of targeted eosinophil depletion

Over the past years, eosinophils have become a focus of scientific interest, especially in the context of their recently uncovered functions (e.g. antiviral, anti-inflammatory, regulatory). These versatile cells display both beneficial and detrimental activities under various physiological and pathological conditions. Eosinophils are involved in the pathogenesis of many diseases which can be classified into primary (clonal) and secondary (reactive) disorders and idiopathic (hyper)eosinophilic syndromes. Depending on the biological specimen, the eosinophil count in different body compartments may serve as a biomarker reflecting the underlying pathophysiology and/or activity of distinct diseases and as a therapy-driving (predictive) and monitoring tool. Personalized selection of an appropriate therapeutic strategy directly or indirectly targeting the increased number and/or activity of eosinophils should be based on the understanding of eosinophil homeostasis including their interactions with other immune and non-immune cells within different body compartments. Hence, restoring as well as maintaining homeostasis within an individual's eosinophil pool is a goal of both specific and non-specific eosinophil-targeting therapies. Despite the overall favourable safety profile of the currently available anti-eosinophil biologics, the effect of eosinophil depletion should be monitored from the perspective of possible unwanted consequences.

A Rapid Sputum-based Lateral Flow Assay for Airway Eosinophilia using an RNA-cleaving DNAzyme Selected for Eosinophil Peroxidase

The first protein-binding allosteric RNA-cleaving DNAzyme (RCD) obtained by direct in vitro selection against eosinophil peroxidase (EPX), a validated marker for airway eosinophilia, is described. The RCD has nanomolar affinity for EPX, shows high selectivity against related peroxidases and other eosinophil proteins, and is resistant to degradation by mammalian nucleases. An optimized RCD was used to develop both fluorescence and lateral flow assays, which were evaluated using 38 minimally processed patient sputum samples (23 non-eosinophilic, 15 eosinophilic), producing a clinical sensitivity of 100 % and specificity of 96 %. This RCD-based lateral flow assay should allow for rapid evaluation of airway eosinophilia as an aid for guiding asthma therapy.

Economic impact of a more extensive use of FENO testing on the Italian population with asthma

BACKGROUND

Asthma is a common chronic inflammatory airway affecting over 260 million people worldwide, and characterized, in the large majority of cases, by the so-called "type 2 inflammation". Fractional exhaled nitric oxide (FE_NO) testing is noninvasive point-of-care tool to assess type 2 inflammation and therefore improve asthma management. It has been suggested to determine eligibility for a specific biologic therapy and predict likelihood to respond. The aim of this study was to estimate the overall economic impact of an extensive use of FE_NO testing on the Italian population with asthma, including extra costs of testing and savings generated by more appropriate prescriptions, increased adherence and lower frequency of exacerbations.

METHODS

A cost of illness analysis was firstly performed to estimate the yearly economic burden from the National Healthcare Service (NHS) perspective in Italy of the management of asthmatic patients with standard of care (SOC) according to the application of GINA (Global Initiative for Asthma) guidelines; then, we evaluated the changes in the economic burden in patient management by introducing FE_NO testing into clinical practice. The cost items considered were: visits/exams, exacerbations, drugs, management of adverse events caused by short-term oral corticosteroids use. Efficacy of FeNO test and SOC is based on literature evidence. Costs refer to published data or Diagnosis Related Group/outpatient tariffs.

RESULTS

Considering one asthma visit every 6 months, the total yearly cost for the management of patients with asthma in Italy is 1,599,217,876€ (409.07€ per patient), while for FE_NO testing strategy this figure is 1,395,029,747€ (356.84€ per patient). An increased utilization rate of FE_NO testing from 50 to 100% of patients may lead to savings for the NHS from about 102 to 204 million € compared to SOC.

CONCLUSIONS

Our study showed that FeNO testing strategy may improve the management of asthmatic patients leading to significant savings for the NHS.

Delineating asthma according to inflammation phenotypes with a focus on paucigranulocytic asthma

ABSTRACT

Asthma is characterized by chronic airway inflammation and airway hyper-responsiveness. However, the differences in pathophysiology and phenotypic symptomology make a diagnosis of "asthma" too broad hindering individualized treatment. Four asthmatic inflammatory phenotypes have been identified based on inflammatory cell profiles in sputum: eosinophilic, neutrophilic, paucigranulocytic, and mixed-granulocytic. Paucigranulocytic asthma may be one of the most common phenotypes in stable asthmatic patients, yet it remains much less studied than the other inflammatory phenotypes. Understanding of paucigranulocytic asthma in terms of phenotypic discrimination, distribution, stability, surrogate biomarkers, underlying pathophysiology, clinical characteristics, and current therapies is fragmented, which impedes clinical management of patients. This review brings together existing knowledge and ongoing research about asthma phenotypes, with a focus on paucigranulocytic asthma, in order to present a comprehensive picture that may clarify specific inflammatory phenotypes and thus improve clinical diagnoses and disease management.

The Pathology of Asthma: What Is Obstructing Our View?

Despite the advent of sophisticated and efficient new biologics to treat inflammation in asthma, the disease persists. Even following treatment, many patients still experience the well-known symptoms of wheezing, shortness of breath, and coughing. What are we missing? Here we examine the evidence that mucus plugs contribute to a substantial portion of disease, not only by physically obstructing the airways but also by perpetuating inflammation. In this way, mucus plugs may act as an immunogenic stimulus even in the absence of allergen or with the use of current therapeutics. The alterations of several parameters of mucus biology, driven by type 2 inflammation, result in sticky and tenacious sputum, which represents a potent threat, first due to the difficulties in expectoration and second by acting as a platform for viral, bacterial, or fungal colonization that allows exacerbations. Therefore, in this way, mucus plugs are an overlooked but critical feature of asthmatic airway disease.

Upper airway disease diagnosis as a predictive biomarker of therapeutic response to biologics in severe asthma

Asthma is a heterogeneous disease sharing airway instability but with different biology, risk factors, and response-to-therapy patterns. Biologics have revolutionized the one-size-fits-to-all approach to personalized medicine in severe asthma (SA), which relies on the identification of biomarkers that define distinct endotypes. Thus, blood eosinophils and, to some extent, exhaled nitric oxide (FeNO) can predict the response to approved anti-type 2 (T2) biologics (anti-IgE, anti-IL-5, and anti-IL-4R alpha), whereas age at onset and comorbidities such as anxiety/depression, obesity, reflux, and upper airway disease (UAD) also influence therapeutic responses in SA. In this article, focusing on the predictive value of biomarkers for the therapeutic response to biologics in SA, we first summarize the level of prediction achieved by T2 biomarkers (blood eosinophils, FeNO) and then review whether data support the predictive value of upper airway diagnosis on such outcomes. Post hoc analysis of most studies with T2 biologics suggests that chronic rhinosinusitis with nasal polyps (CRSwNP) and, to a lower extent, allergic rhinitis may help in predicting clinical response. Considering that T2 biologics are now also approved for the treatment of severe CRSwNP, diagnosis of upper airway disease is a key step in determining eligibility for such therapy.

Consensus on mild asthma management: results of a modified Delphi study

OBJECTIVE

In order to understand the role of regular controller inhaled corticosteroids (ICS) versus as-needed ICS-formoterol in managing mild asthma, we performed a modified Delphi procedure.

METHODS

Opinions from 16 respiratory experts to three surveys and during a virtual scientific workshop helped to develop final consensus statements (pre-defined as 70% agreement).

RESULTS

Thirteen participants completed all rounds (response rate 81%). At the end of the procedure, there was final consensus on: regular daily ICS being the recommended treatment approach in mild persistent asthma, with better symptom control and robust long-term clinical data compared with as-needed ICS-formoterol (85%); to avoid noncompliance, frequently seen in mild asthma patients, regular ICS dosing should be accompanied by ongoing education on treatment adherence (100%); treatment aims should be targeting asthma control (92%) and reduction of exacerbation risk (85%). No consensus was reached on whether GINA or national guidelines most influence prescribing decisions.

CONCLUSIONS

It is important to encourage patients to be adherent and to target both asthma control and exacerbation risk reduction. There is robust clinical evidence to support proactive regular dosing with ICS controller therapy plus as-needed short-acting beta-agonists for the management of patients with mild asthma.

ABBREVIATIONS.

Supplemental data for this article is available online at https://doi.org/10.1080/02770903.2022.2034850 .

Symptom versus exacerbation control: an evolution in GINA guidelines?

The article traces the concept of asthma control within GINA guidelines over the past 25 years. In the first 15 years after 1995, the main objective of asthma management was to obtain the control of all clinical and functional characteristics of asthma. A landmark study (GOAL) showed for the first time that a good control of asthma is a reasonable outcome that can be achieved in a large proportion of asthmatics with a regular appropriate treatment. In the following years, more emphasis was placed on the role of exacerbations as critical manifestations of poor asthma control, whose frequency is associated with excessive FEV1 decline and increased risk of death. Accordingly, the 2014 GINA report makes a clear distinction between the control of the day-by-day symptoms and the reduction in the risk of severe exacerbations, stating that both conditions should be obtained. The 2019 update included a significant change in the management of mild asthma, prioritizing the prevention of exacerbations to that of mild symptoms. This view was repeated in the 2021 update, where the prevention of exacerbations, together with an acceptable symptom control with a minimal use of rescue medication, appeared to be the real main goal of asthma management. While a discrepancy between current symptoms and exacerbations may be present in mild asthma, a significant relationship between these two features is observed in moderate-severe asthma: a persistent poor symptom control is a major risk factor for exacerbations, whereas achieving symptom control through regular treatment is associated with a reduction in exacerbation rate. Thus, the opinion that frequent symptoms are not important in the absence of acute exacerbations should be discouraged, whereas education of patients to a good symptom perception and to improve adherence to regular treatment should be implemented. Furthermore, the persistence of risk factors, such as increased airway inflammation, even in a patient with minor daily symptoms, should be considered for optimizing treatment.

A sputum bioassay for airway eosinophilia using an eosinophil peroxidase aptamer

Eosinophils are granulocytes that play a significant role in the pathogenesis of asthma and other airway diseases. Directing patient treatment based on the level of eosinophilia has been shown to be extremely effective in reducing exacerbations and therefore has tremendous potential as a routine clinical test. Herein, we describe the in vitro selection and optimization of DNA aptamers that bind to eosinophil peroxidase (EPX), a protein biomarker unique to eosinophils. Fifteen rounds of magnetic bead aptamer selection were performed prior to high throughput DNA sequencing. The top 10 aptamer candidates were assessed for EPX binding using a mobility shift assay. This process identified a lead aptamer candidate termed EAP1-05 with low nanomolar affinity and high specificity for EPX over other common sputum proteins. This aptamer sequence was further optimized through truncation and used to develop an easy-to-use colourimetric pull-down assay that can detect EPX over a concentration range from 1 - 100 nM in processed sputum. Forty-six clinical samples were processed using a new sputum dispersal method, appropriate for a rapid assessment assay, that avoids centrifugation and lengthy processing times. The assay showed 89% sensitivity and 96% specificity to detect eosinophilia (compared to gold standard sputum cytometry), with results being produced in under an hour. This assay could allow for an easy assessment of eosinophil activity in the airway to guide anti-inflammatory therapy for several airway diseases.

Critical evaluation of asthma biomarkers in clinical practice

The advent of personalized medicine has revolutionized the whole approach to the management of asthma, representing the essential basis for future developments. The cornerstones of personalized medicine are the highest precision in diagnosis, individualized prediction of disease evolution, and patient-tailored treatment. To this aim, enormous efforts have been established to discover biomarkers able to predict patients' phenotypes according to clinical, functional, and bio-humoral traits. Biomarkers are objectively measured characteristics used as indicators of biological or pathogenic processes or clinical responses to specific therapeutic interventions. The diagnosis of type-2 asthma, prediction of response to type-2 targeted treatments, and evaluation of the risk of exacerbation and lung function impairment have been associated with biomarkers detectable either in peripheral blood or in airway samples. The surrogate nature of serum biomarkers, set up to be less invasive than sputum analysis or bronchial biopsies, has shown several limits concerning their clinical applicability. Routinely used biomarkers, like peripheral eosinophilia, total IgE, or exhaled nitric oxide, result, even when combined, to be not completely satisfactory in segregating different type-2 asthma phenotypes, particularly in the context of severe asthma where the choice among different biologics is compelling. Moreover, the type-2 low fraction of patients is not only an orphan of biological treatments but is at risk of being misdiagnosed due to the low negative predictive value of type-2 high biomarkers. Sputum inflammatory cell analysis, considered the highest specific biomarker in discriminating eosinophilic inflammation in asthma, and therefore elected as the gold standard in clinical trials and research models, demonstrated many limits in clinical applicability. Many factors may influence the measure of these biomarkers, such as corticosteroid intake, comorbidities, and environmental exposures or habits. Not least, biomarkers variability over time is a confounding factor leading to wrong clinical choices. In this narrative review, we try to explore many aspects concerning the role of routinely used biomarkers in asthma, applying a critical view over the "state of the art" and contemporarily offering an overview of the most recent evidence in this field.

Phenotyping, Precision Medicine, and Asthma

The traditional one-size-fits all approach based on asthma severity is archaic. Asthma is a heterogenous syndrome rather than a single disease entity. Studies evaluating observable characteristics called phenotypes have elucidated this heterogeneity. Asthma clusters demonstrate overlapping features, are generally stable over time and are reproducible. What the identification of clusters may have failed to do, is move the needle of precision medicine meaningfully in asthma. This may be related to the lack of a straightforward and clinically meaningful way to apply what we have learned about asthma clusters. Clusters are based on both clinical factors and biomarkers. The use of biomarkers is slowly gaining popularity, but phenotyping based on biomarkers is generally greatly underutilized even in subspecialty care. Biomarkers are more often used to evaluate type 2 (T2) inflammatory signatures and eosinophils (sputum and blood), fractional exhaled nitric oxide (FeNO) and serum total and specific immunoglobulin (Ig) E reliably characterize the underlying inflammatory pathways. Biomarkers perform variably and clinicians must be familiar with their advantages and disadvantages to accurately apply them in clinical care. In addition, it is increasingly clear that clinical features are critical in understanding not only phenotypic characterization but in predicting response to therapy and future risk of poor outcomes. Strategies for asthma management will need to leverage our knowledge of biomarkers and clinical features to create composite scores and risk prediction tools that are clinically applicable. Despite significant progress, many questions remain, and more work is required to accurately identify non-T2 biomarkers. Adoption of phenotyping and more consistent use of biomarkers is needed, and we should continue to encourage this incorporation into practice.

Recent insights in the role of biomarkers in severe asthma management

Contemporary asthma management requires a proactive and individualized approach, combining precision diagnosis and personalized treatment. The introduction of biologic therapies for severe asthma to everyday clinical practice, increases the need for specific patient selection, prediction of outcomes and monitoring of these costly and long-lasting therapies. Several biomarkers have been used in asthma in disease identification, prediction of asthma severity and prognosis, and response to treatment. Novel advances in the area of personalized medicine regarding disease phenotyping and endotyping, encompass the development and application of reliable biomarkers, accurately quantified using robust and reproducible methods. The availability of powerful omics technologies, together with integrated and network-based genome data analysis, and microbiota changes quantified in serum, body fluids and exhaled air, will lead to a better classification of distinct phenotypes or endotypes. Herein, in this review we discuss on currently used and novel biomarkers for the diagnosis and treatment of asthma.

Switching Treatment from Mepolizumab to Benralizumab for Elderly Patients with Severe Eosinophilic Asthma: A Retrospective Observational Study

Objective Switching from mepolizumab to benralizumab has been reported to significantly improve both asthma control and the lung function. However, the data on its efficacy in elderly patients with severe eosinophilic asthma are limited. This study aimed to assess whether elderly patients with severe eosinophilic asthma could experience an improved asthma control and lung function when switching directly from mepolizumab to benralizumab. Methods In this single-center, retrospective study conducted between February 2017 and September 2018, we assessed the effect of switching the treatment directly from mepolizumab to benralizumab on eosinophil levels, exacerbation rates, and lung function. We compared the treatment responses between the two groups using either Fisher's exact test or Mann-Whitney U-test, as appropriate. Patients We enrolled 12 elderly patients (age ≥65 years) with severe eosinophilic asthma treated with mepolizumab at Hiroshima Prefectural Hospital (Hiroshima, Japan) during the study period. Six patients were switched from mepolizumab to benralizumab, and six continued with the mepolizumab treatment. Results The switch from mepolizumab to benralizumab caused a near-complete reduction in the eosinophil count (p=0.008). The annual rate of clinically relevant exacerbations and hospitalizations diminished as well, albeit with no statistical significance. We found no improvement in the lung function after switching treatment and no difference in the treatment response between the groups. Conclusion Although this study is based on a small sample of participants, the results indicate that both mepolizumab treatment and switching from mepolizumab to benralizumab treatment without a washout period have clinically relevant asthma control benefits for elderly patients with severe eosinophilic asthma.

Should we apply a treatable traits approach to asthma care?

OBJECTIVE

To explore the evidence for adopting a "treatable traits" approach to asthma management.

DATA SOURCES

PubMed, Medline, and Google Scholar.

STUDY SELECTIONS

The above-mentioned databases were searched for randomized, controlled phase III or IV trials of adults containing the word "asthma" in the title published in the previous 10 years and for all articles containing the title words "treatable AND trait(s)," "asthma AND biomarker(s) OR smoking OR obesity OR laryngeal OR management" published within the previous 5 years. Articles were excluded if they were not published in English. Our search identified 257 articles for consideration. We also manually searched the reference lists of studies identified and searched the websites of the British Thoracic Society, European Respiratory Society, National Institute for Health and Care Excellence, and Global Initiative for Asthma for specific guidance related to asthma management.

RESULTS

The "treatable traits" are described within 3 domains of pulmonary, extrapulmonary, or behavioral and lifestyle traits. We consider whether treatment should be targeted toward these traits where they are present in asthma patients, based on currently available evidence, rather than increasing treatment in response to symptoms in line with current step-up, step-down asthma management guidelines.

CONCLUSION

We advocate that a treatable traits approach should be applied more broadly to the assessment and management of inadequately controlled asthma, rather than a step-up, step-down approach based on patient symptoms. This approach should be focused on the 2 treatable pulmonary traits of T_H2 inflammation and airflow obstruction along with smoking cessation, in the first instance.

Identification of Key Signaling Pathways and Genes in Eosinophilic Asthma and Neutrophilic Asthma by Weighted Gene Co-Expression Network Analysis

Background: Asthma is a heterogeneous disease with different subtypes including eosinophilic asthma (EA) and neutrophilic asthma (NA). However, the mechanisms underlying the difference between the two subtypes are not fully understood.

Methods: Microarray datasets (GSE45111 and GSE137268) were acquired from Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) in induced sputum between EA (n = 24) and NA (n = 15) were identified by “Limma” package. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses and Gene set enrichment analysis (GSEA) were used to explore potential signaling pathways. Weighted gene co-expression network analysis (WGCNA) were performed to identify the key genes that were strongly associated with EA and NA.

Results: A total of 282 DEGs were identified in induced sputum of NA patients compared with EA patients. In GO and KEGG pathway analyses, DEGs were enriched in positive regulation of cytokine production, and cytokine-cytokine receptor interaction. The results of GSEA showed that ribosome, Parkinson’s disease, and oxidative phosphorylation were positively correlated with EA while toll-like receptor signaling pathway, primary immunodeficiency, and NOD-like receptor signaling pathway were positively correlated with NA. Using WGCNA analysis, we identified a set of genes significantly associated NA including IRFG, IRF1, STAT1, IFIH1, IFIT3, GBP1, GBP5, IFIT2, CXCL9, and CXCL11.

Conclusion: We identified potential signaling pathways and key genes involved in the pathogenesis of the asthma subsets, especially in neutrophilic asthma.

2021 Brazilian Thoracic Association recommendations for the management of severe asthma

Advances in the understanding that severe asthma is a complex and heterogeneous disease and in the knowledge of the pathophysiology of asthma, with the identification of different phenotypes and endotypes, have allowed new approaches for the diagnosis and characterization of the disease and have resulted in relevant changes in pharmacological management. In this context, the definition of severe asthma has been established, being differentiated from difficult-to-control asthma. These recommendations address this topic and review advances in phenotyping, use of biomarkers, and new treatments for severe asthma. Emphasis is given to topics regarding personalized management of the patient and selection of biologicals, as well as the importance of evaluating the response to treatment. These recommendations apply to adults and children with severe asthma and are targeted at physicians involved in asthma treatment. A panel of 17 Brazilian pulmonologists was invited to review recent evidence on the diagnosis and management of severe asthma, adapting it to the Brazilian reality. Each of the experts was responsible for reviewing a topic or question relevant to the topic. In a second phase, four experts discussed and structured the texts produced, and, in the last phase, all experts reviewed and approved the present manuscript and its recommendations.

Pulmonary Eosinophils at the Center of the Allergic Space-Time Continuum

Eosinophils are typically a minority population of circulating granulocytes being released from the bone-marrow as terminally differentiated cells. Besides their function in the defense against parasites and in promoting allergic airway inflammation, regulatory functions have now been attributed to eosinophils in various organs. Although eosinophils are involved in the inflammatory response to allergens, it remains unclear whether they are drivers of the asthma pathology or merely recruited effector cells. Recent findings highlight the homeostatic and pro-resolving capacity of eosinophils and raise the question at what point in time their function is regulated. Similarly, eosinophils from different physical locations display phenotypic and functional diversity. However, it remains unclear whether eosinophil plasticity remains as they develop and travel from the bone marrow to the tissue, in homeostasis or during inflammation. In the tissue, eosinophils of different ages and origin along the inflammatory trajectory may exhibit functional diversity as circumstances change. Herein, we outline the inflammatory time line of allergic airway inflammation from acute, late, adaptive to chronic processes. We summarize the function of the eosinophils in regards to their resident localization and time of recruitment to the lung, in all stages of the inflammatory response. In all, we argue that immunological differences in eosinophils are a function of time and space as the allergic inflammatory response is initiated and resolved.

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.

Asthma COPD overlap: Insights into cellular and molecular mechanisms

Although there is still no consensus on the definition of Asthma-COPD Overlap (ACO), it is generally accepted that some patients with airway disease have features of both asthma and COPD. Just as its constituents, ACO consists of different phenotypes, possibly depending on the predominance of the underlying asthma or COPD-associated pathophysiological mechanisms. The clinical picture is influenced by the development of airway inflammatory processes either eosinophilic, neutrophilic or mixed, in addition to glandular changes leading to mucus hypersecretion and a variety of other airway structural changes. Although animal models have exposed how smoking-related changes can interact with those observed in asthma, much remains to be known about their interactions in humans and the additional modulating effects of environmental exposures. There is currently no solid evidence to establish the optimal treatment of ACO but it should understandably include an avoidance of environmental triggers such as smoking and relevant allergens. The recognition and targeting of "treatable traits" following phenotyping is a pragmatic approach to select the optimal pharmacological treatment for ACO, although an association of inhaled corticosteroids and bronchodilators is always required in these patients. This association acts both as an anti-inflammatory treatment for the asthma component and as a functional antagonist for the airway remodeling features. Research should be promoted on well phenotyped subgroups of ACO patients to determine their optimal management.

Pathological Roles and Clinical Usefulness of Periostin in Type 2 Inflammation and Pulmonary Fibrosis

Periostin is known to be a useful biomarker for various diseases. In this article, we focus on allergic diseases and pulmonary fibrosis, for which we and others are now developing detection systems for periostin as a biomarker. Biomarker-based precision medicine in the management of type 2 inflammation and fibrotic diseases since heterogeneity is of utmost importance. Periostin expression is induced by type 2 cytokines (interleukin-4/-13) or transforming growth factor-β, and plays a vital role in the pathogenesis of allergic inflammation or interstitial lung disease, respectively, andits serum levels are correlated disease severity, prognosis and responsiveness to the treatment. We first summarise the importance of type 2 biomarker and then describe the pathological role of periostin in the development and progression of type 2 allergic inflammation and pulmonary fibrosis. In addition, then, we summarise the recent development of assay methods for periostin detection, and analyse the diseases in which periostin concentration is elevated in serum and local biological fluids and its usefulness as a biomarker. Furthermore, we describe recent findings of periostin as a biomarker in the use of biologics or anti-fibrotic therapy. Finally, we describe the factors that influence the change in periostin concentration under the healthy conditions.

Biomarkers of asthma

Biomarkers may be diagnostic of asthma, they may predict or reflect response to therapy or they may identify patients at risk of asthma exacerbation. A biomarker is most often measured in biologic fluids that are sampled using relatively non-invasive sampling techniques such as blood, sputum, urine or exhaled breath. Biomarkers should be stable, readily quantifiable and their measurement should be reproducible and not confounded by other host factors, or the presence of comorbidities. However, asthma comprises multiple molecular endotypes and single, sensitive, specific, biomarkers reflecting these endotypes may not exist. Combining biomarkers may improve their predictive capability in asthma. The most well-established endotypes are those described as Type2 and non-Type2 asthma. Clinical trials established the fraction of exhaled nitric oxide (FeNO) and blood eosinophil counts as key biomarkers of response to corticosteroid or targeted anti-inflammatory therapy in Type2 asthma. However, these biomarkers may have limited value in the management of asthma in real-life settings or routine clinical practise. Biomarkers for Type2 asthma are not well described or validated and more research is needed. Breathomics has provided evidence to propose a number of exhaled volatile organic compounds (VOCs) as surrogate biomarkers for airway inflammatory phenotypes, disease activity and adherence to therapy. Analysis of urinary eicosanoids has identified eicosanoids related to Type2 and non-Type2 inflammation. Future clinical trials will be important in determining how exhaled VOCs or urinary eicosanoid profiles can be used to direct precision treatments. Their future clinical use will also depend on developing simplified instrumentation for biomarker analysis at the point-of-care.

Stability of sputum inflammatory phenotypes in childhood asthma during stable and exacerbation phases

BACKGROUND

Management strategies based on airway inflammation phenotypes are increasingly used for adults with asthma. While sputum-based phenotypes are relatively stable in adults with asthma, there is little such data in childhood asthma. Hence, we aimed to evaluate the stability of sputum inflammatory phenotypes in children with asthma both in the stable and during exacerbation phases.

METHODS

Sputum cellularity data from two previous prospective studies involving children with asthma were re-evaluated and categorized into two inflammatory phenotypes: eosinophilic (>2.5% eosinophils) and noneosinophilic (≤2.5% eosinophils). Baseline values and follow-up sputum inflammatory phenotype classification were compared in children with asthma during stable and exacerbation phases.

RESULTS

Thirteen of 32 children (41%) with stable asthma demonstrated a change in sputum inflammatory phenotype 8 weeks later. In a different second cohort, both sputum eosinophils and neutrophils percentages increased and peaked on Day 1 of asthma exacerbation, but compared with baseline, 22% (2/9) and 13% (1/8) of these children had their sputum phenotype categorization changed on Day 1 and Day 3 of exacerbation, respectively.

CONCLUSION

In children with asthma, sputum inflammatory phenotypes are variable in both stable and exacerbation phases, in contrast to data in adults.

Semaphorin3E/plexinD1 Axis in Asthma: What We Know So Far!

Semaphorin3E belongs to the large family of semaphorin proteins. Semaphorin3E was initially identified as axon guidance cues in the neural system. It is universally expressed beyond the nervous system and contributes to regulating essential cell functions such as cell migration, proliferation, and adhesion. Binding of semaphorin3E to its receptor, plexinD1, triggers diverse signaling pathways involved in the pathogenesis of various diseases from cancer to autoimmune and allergic disorders. Here, we highlight the novel findings on the role of semaphorin3E in airway biology. In particular, we highlight our recent findings on the function and potential mechanisms by which semaphorin3E and its receptor, plexinD1, impact airway inflammation, airway hyperresponsiveness, and remodeling in the context of asthma.

Biomarkers in Different Asthma Phenotypes

Asthma is the most common respiratory disease. It has multiple phenotypes thatcan be partially differentiated by measuring the disease’s specific characteristics—biomarkers. The pathogenetic mechanisms are complex, and it is still a challenge to choose suitable biomarkers to adequately stratify patients, which became especially important with the introduction of biologicals in asthma treatment. Usage of biomarkers and an understanding of the underlying pathobiological mechanisms lead to the definition of endotypes. Asthma can be broadly divided into two endotypes, T2-high and T2-low. The right combination of various biomarkers in different phenotypes is under investigation, hoping to help researchers and clinicians in better disease evaluation since theindividual approach and personalized medicine are imperative. Multiple biomarkers are superior to a single biomarker.

Precision Medicine for Paediatric Severe Asthma: Current Status and Future Direction

Asthma is a heterogeneous disease, characterised by different phenotypes and endotypes. Precision medicine in asthma refers to the implementation of a targeted therapy for each individual child, based on the identification of treatable traits, including environmental, immunological and genetic factors. Severe asthma in children is associated with increased hospitalisation rates, a lower quality of life, increased healthcare costs and an increased mortality. In the era of new molecular biologics treatments, it is essential to improve deep phenotyping of children with severe asthma in order to deliver the most effective treatment to each individual child. In this review, we discuss the personalised approach to the assessment and management of severe asthma. We explore the indications and use of the currently licensed biologics, as well as the potential of other emerging treatments.

The role of eosinophils in sepsis and acute respiratory distress syndrome: a scoping review

PURPOSE

Septic shock and acute respiratory distress syndrome (ARDS) are characterized by a dysregulated immune host response that may respond to steroid therapy. Eosinophils contribute to type 2 inflammation that often responds to steroid therapy; their role in immune dysregulation and outcomes in sepsis and ARDS is unclear.

SOURCE

A systematic search of Cochrane Library, MEDLINE, and EMBASE was performed from inception to 9 September 2020. The search comprised the following terms: eosinophils, sepsis, septic shock, and ARDS. Two reviewers independently screened abstracts and texts and extracted data on disease severity and clinical outcomes.

PRINCIPAL FINDINGS

Thirty-nine studies were identified: 30 evaluated serum eosinophil count in sepsis, one evaluated eosinophil activity in sepsis, three assessed bronchoalveolar lavage (BAL) eosinophil count in ARDS, four assessed eosinophil activity in ARDS, and one assessed peripheral eosinophil count in ARDS. Eleven studies showed an association between eosinopenia and sepsis, and eight studies found persistent eosinopenia at > 48 hr of intensive care unit admission to predict mortality and readmission in septic patients. Three studies found BAL eosinophil count to be low in ARDS, although one found that levels rose in late-phase ARDS. Three studies found eosinophil activity markers in BAL to be high in ARDS and correlate with ARDS severity.

CONCLUSION

Persistent peripheral eosinopenia is a marker of bacterial sepsis and is independently associated with poor outcomes. Bronchoalveolar lavage eosinophil counts are low in early-phase ARDS, but increase in late-phase ARDS, while elevated markers of eosinophil activity correlate with ARDS severity. Further studies understanding the mechanisms leading to eosinopenia in sepsis and increased eosinophil activity in ARDS are needed.

Mepolizumab asthma treatment failure due to refractory airway eosinophilia, which responded to benralizumab

Monoclonal antibodies directed against interleukin (IL)-5, such as mepolizumab and benralizumab, are an effective and established treatment for severe eosinophilic asthma. Here, we present a patient with eosinophilic asthma with a partial clinical response to mepolizumab initially, as measured by these biomarkers, who when investigated was found to have refractory airway eosinophilia. Escalation of the mepolizumab dose led to further but still only partial response. A treatment trial with benralizumab was more successful and led to suppression of airway eosinophilia. We review the literature, focusing on eosinophil biology at the tissues and the different mechanisms of action of the two agents.

Expert Consensus on the Tapering of Oral Corticosteroids for the Treatment of Asthma. A Delphi Study

Rationale: There is a need to minimize oral corticosteroid (OCS) use in patients with asthma to prevent their costly and burdensome adverse effects. Current guidelines do not provide recommendations for OCS tapering in patients with asthma.Objectives: To develop expert consensus on OCS tapering among international experts.Methods: A modified Delphi method was used to develop expert consensus statements relating to OCS use, tapering, adverse effects, adrenal insufficiency, and patient-physician shared decision-making. Initial statements proposed by experts were categorized, filtered for repetition, and presented back to experts over three ranking rounds to obtain consensus (≥70% agreement).Measurements and Main Results: One hundred thirty-one international experts participated in the study, and 296 statements were ranked. Numerous recommendations and guidance regarding appropriate OCS use were established. Experts agreed that OCS tapering should be attempted in all patients with asthma receiving maintenance OCS therapy, with personalization of tapering rhythm and speed. The importance of recognizing individual adverse effects was also established; however, a unified approach to the assessment of adrenal insufficiency was not reached. Shared decision-making was considered an important goal during the tapering process.Conclusions: In this Delphi study, expert consensus statements were generated on OCS use, tapering, adverse-effect screening, and shared decision-making, which may be used to inform clinical practice. Areas of nonconsensus were identified, highlighting uncertainty among the experts around some aspects of OCS use in asthma, such as adrenal insufficiency, which underscores the need for further research in these domains.

Discontinuation of inhaled corticosteroids in patients with controlled asthma: The DISCO (Discontinuation of Inhaled Steroid in Controlled asthmatics Over 6 months) study

BACKGROUND

Although inhaled corticosteroids (ICSs) are the recommended first-line therapy for asthma, determining whether to continue or discontinue ICS treatment in patients with mild asthma remains challenging for clinicians. Several studies have revealed that patients with mild-persistent asthma maintained a well-controlled state after ICS withdrawal. However, the long-term outcomes of ICS withdrawal have not yet been determined.

OBJECTIVE

To determine the possible clinical outcomes of the discontinuation of ICS in patients with well-controlled mild asthma.

METHODS

We investigated the clinical outcomes of discontinuing ICSs in patients with well-controlled mild asthma and compared the time to loss of control (LOC) between patients who stopped ICS treatment (ICS withdrawal group, IWG) and those who continued treatment for 3 years (continuous ICS group, CIG).

RESULTS

A significant difference in the time to LOC was observed between the IWG and CIG (hazard ratio, 2.56; 95% confidence interval, 1.52-4.33; P < .001). Increasing fractional exhaled nitric oxide levels (P = 0.008) and sputum eosinophil counts (%) (P = 0.015) revealed a weak but significant association with LOC risk in the CIG. The sputum eosinophil counts (P = 0.039) and serum total immunoglobulin E levels (P = 0.014) were significantly higher in the LOC group than in the non-LOC group of the CIG.

CONCLUSION

Our results suggest that the maintenance of ICS treatment may help keep patients' asthma under control. Furthermore, patients with LOC had significantly higher sputum eosinophil counts in the CIG than those in the non-LOC group. Therefore, continuous ICS use by patients with mild, well-controlled asthma could be associated with good clinical outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: KCT0002234.

Neutrophils in asthma: the good, the bad and the bacteria

Airway inflammation plays a key role in asthma pathogenesis but is heterogeneous in nature. There has been significant scientific discovery with regard to type 2-driven, eosinophil-dominated asthma, with effective therapies ranging from inhaled corticosteroids to novel biologics. However, studies suggest that approximately 1 in 5 adults with asthma have an increased proportion of neutrophils in their airways. These patients tend to be older, have potentially pathogenic airway bacteria and do not respond well to classical therapies. Currently, there are no specific therapeutic options for these patients, such as neutrophil-targeting biologics.Neutrophils comprise 70% of the total circulatory white cells and play a critical defence role during inflammatory and infective challenges. This makes them a problematic target for therapeutics. Furthermore, neutrophil functions change with age, with reduced microbial killing, increased reactive oxygen species release and reduced production of extracellular traps with advancing age. Therefore, different therapeutic strategies may be required for different age groups of patients.The pathogenesis of neutrophil-dominated airway inflammation in adults with asthma may reflect a counterproductive response to the defective neutrophil microbial killing seen with age, resulting in bystander damage to host airway cells and subsequent mucus hypersecretion and airway remodelling. However, in children with asthma, neutrophils are less associated with adverse features of disease, and it is possible that in children, neutrophils are less pathogenic.In this review, we explore the mechanisms of neutrophil recruitment, changes in cellular function across the life course and the implications this may have for asthma management now and in the future. We also describe the prevalence of neutrophilic asthma globally, with a focus on First Nations people of Australia, New Zealand and North America.

Balancing the needs of the many and the few: where next for adult asthma guidelines?

Asthma differs from many other chronic conditions in that most key management decisions are made in non-specialist settings, such as general practitioner surgeries and accident and emergency departments. Diagnosis in primary care relies on recognition of a characteristic pattern of symptoms and the occurrence of asthma attacks, sometimes supplemented by basic lung function tests. Ongoing management is guided by the assessment of symptoms and simple lung function measures of airflow obstruction, with little attempt made to personalise management. This approach is flawed because the inadequate specificity of symptoms, as well as the low sensitivity of variable airflow obstruction, means that a diagnosis of asthma is often difficult to exclude with confidence. Moreover, even if diagnosed correctly, dissociation between inflammation, airflow obstruction, and symptoms means that a generalised stepwise approach to managing asthma on the basis of symptoms is unlikely to be successful in a substantial proportion of patients. As a result, effective treatments are used inefficiently, and outcomes are often worse than they could be. Rather than use of either a population-based or personalised approach for the diagnosis and management of asthma, we recommend a new combined approach, in which treatment decisions are driven by objective assessment of key treatable mechanistic traits.

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.

Modern View of Neutrophilic Asthma Molecular Mechanisms and Therapy

For a long time asthma was commonly considered as a homogeneous disease. However, recent studies provide increasing evidence of its heterogeneity and existence of different phenotypes of the disease. Currently, classification of asthma into several phenotypes is based on clinical and physiological features, anamnesis, and response to therapy. This review describes five most frequently identified asthma phenotypes. Neutrophilic asthma (NA) deserves special attention, since neutrophilic inflammation of the lungs is closely associated with severity of the disease and with the resistance to conventional corticosteroid therapy. This review focuses on molecular mechanisms of neutrophilic asthma pathogenesis and on the role of Th1- and Th17-cells in the development of this type of asthma. In addition, this review presents current knowledge of neutrophil biology. It has been established that human neutrophils are represented by at least three subpopulations with different biological functions. Therefore, total elimination of neutrophils from the lungs can result in negative consequences. Based on the new knowledge of NA pathogenesis and biology of neutrophils, the review summarizes current approaches for treatment of neutrophilic asthma and suggests new promising ways to treat this type of asthma that could be developed in future.

Treatment options in type-2 low asthma

Monoclonal antibodies targeting IgE or the type-2 cytokines interleukin (IL)-4, IL-5 and IL-13 are proving highly effective in reducing exacerbations and symptoms in people with severe allergic and eosinophilic asthma, respectively. However, these therapies are not appropriate for 30-50% of patients in severe asthma clinics who present with non-allergic, non-eosinophilic, "type-2 low" asthma. These patients constitute an important and common clinical asthma phenotype, driven by distinct, yet poorly understood pathobiological mechanisms. In this review we describe the heterogeneity and clinical characteristics of type-2 low asthma and summarise current knowledge on the underlying pathobiological mechanisms, which includes neutrophilic airway inflammation often associated with smoking, obesity and occupational exposures and may be driven by persistent bacterial infections and by activation of a recently described IL-6 pathway. We review the evidence base underlying existing treatment options for specific treatable traits that can be identified and addressed. We focus particularly on severe asthma as opposed to difficult-to-treat asthma, on emerging data on the identification of airway bacterial infection, on the increasing evidence base for the use of long-term low-dose macrolides, a critical appraisal of bronchial thermoplasty, and evidence for the use of biologics in type-2 low disease. Finally, we review ongoing research into other pathways including tumour necrosis factor, IL-17, resolvins, apolipoproteins, type I interferons, IL-6 and mast cells. We suggest that type-2 low disease frequently presents opportunities for identification and treatment of tractable clinical problems; it is currently a rapidly evolving field with potential for the development of novel targeted therapeutics.

Anti-alarmins in asthma: targeting the airway epithelium with next-generation biologics

Monoclonal antibody therapies have significantly improved treatment outcomes for patients with severe asthma; however, a significant disease burden remains. Available biologic treatments, including anti-immunoglobulin (Ig)E, anti-interleukin (IL)-5, anti-IL-5Rα and anti-IL-4Rα, reduce exacerbation rates in study populations by approximately 50% only. Furthermore, there are currently no effective treatments for patients with severe, type 2-low asthma. Existing biologics target immunological pathways that are downstream in the type 2 inflammatory cascade, which may explain why exacerbations are only partly abrogated. For example, type 2 airway inflammation results from several inflammatory signals in addition to IL-5. Clinically, this can be observed in how fractional exhaled nitric oxide (F_eNO), which is driven by IL-13, may remain unchanged during anti-IL-5 treatment despite reduction in eosinophils, and how eosinophils may remain unchanged during anti-IL-4Rα treatment despite reduction in F_eNO. The broad inflammatory response involving cytokines including IL-4, IL-5 and IL-13 that ultimately results in the classic features of exacerbations (eosinophilic inflammation, mucus production and bronchospasm) is initiated by release of “alarmins” thymic stromal lymphopoietin (TSLP), IL-33 and IL-25 from the airway epithelium in response to triggers. The central, upstream role of these epithelial cytokines has identified them as strong potential therapeutic targets to prevent exacerbations and improve lung function in patients with type 2-high and type 2-low asthma. This article describes the effects of alarmins and discusses the potential role of anti-alarmins in the context of existing biologics. Clinical phenotypes of patients who may benefit from these treatments are also discussed, including how biomarkers may help identify potential responders.

Blocking epithelial alarmins, upstream mediators triggered early in the asthma inflammatory response that orchestrate broad inflammatory effects, is a promising alternative approach to asthma treatment, which may be effective in a broad patient population https://bit.ly/2zqoXAw

Effect of a single day of increased as-needed budesonide-formoterol use on short-term risk of severe exacerbations in patients with mild asthma: a post-hoc analysis of the SYGMA 1 study

BACKGROUND

In mild asthma, as-needed budesonide-formoterol reduces long-term exacerbation risk compared with as-needed short-acting β₂-agonist (SABA), with a similar or increased reduction versus maintenance with budesonide plus as-needed SABA, despite a lower budesonide dose. In this post-hoc analysis of the SYmbicort Given as needed in Mild Asthma (SYGMA) 1 study, we investigated the short-term risk of severe exacerbations after a single day with various levels of reliever use.

METHODS

SYGMA 1 was a 52-week, double-blind, randomised, controlled, phase 3 trial, in which patients aged 12 years or older with mild asthma were randomly assigned (1:1:1) to placebo twice daily plus as-needed terbutaline 0·5 mg, placebo twice daily plus as-needed budesonide-formoterol 200-6 μg, or budesonide 200 μg twice daily plus as-needed terbutaline (ie, budesonide maintenance group). In this post-hoc analysis, we assessed the frequency of reliever use and the risk of a severe exacerbation in the 21 days after first use of more than two, four, six, or eight reliever inhalations in 24 h. SYGMA 1 is registered with ClinicalTrials.gov, NCT02149199, and is now complete.

FINDINGS

Of 5721 patients enrolled in SYGMA 1, 3849 were randomly assigned to as-needed terbutaline (n=1280), as-needed budesonide-formoterol (n=1279), or budesonide maintenance (n=1290), of whom 3836 had evaluable data (n=1277 as-needed terbutaline, n=1277 as needed budesonide-formoterol, and n=1282 budesonide maintenance). Median reliever use was 0·32 (IQR 0·08-0·91) inhalations per day for the as-needed terbutaline group, 0·29 (0·07-0·72) for the as-needed budesonide-formoterol group, and 0·16 (0·04-0·52) for the budesonide maintenance group. Compared with as-needed terbutaline, after adjustment for age, sex, randomly assigned treatment, pre-study treatment group, baseline % predicted post-bronchodilator FEV₁, and severe exacerbation in the 12 months before enrolment in the study, the hazard ratio (HR) for severe exacerbation in the 21 days after a single day with more than two as-needed inhalations was 0·27 (95% CI 0·12-0·58; p=0·0008) with as-needed budesonide-formoterol and 0·39 (0·19-0·79; p=0·0091) with budesonide maintenance; after a single day of more than four as-needed inhalations the HR was 0·24 (0·10-0·62; p=0·0030) with as-needed budesonide-formoterol and 0·30 (0·13-0·72; p=0·0065) with budesonide maintenance; and after a single day of more than six as-needed inhalations the HR was 0·14 (0·02-1·06; p=0·057) with as-needed budesonide-formoterol and 0·43 (0·14-1·26; p=0·12) with budesonide maintenance. HRs were not calculated for more than eight as-needed inhalations due to the small number of events.

INTERPRETATION

In mild asthma, as-needed budesonide-formoterol reduces the short-term risk of severe exacerbations after a single day of higher use (more than two as-needed inhalations), even when overall use is infrequent. Use of an anti-inflammatory reliever might reduce the risk of short-term severe exacerbations by the timely provision of increased doses of as-needed inhaled corticosteroids and formoterol when symptoms occur. These findings should be further assessed in prospective randomised clinical trials.

FUNDING

AstraZeneca.

Multimodal combination of GC × GC-HRTOFMS and SIFT-MS for asthma phenotyping using exhaled breath

Chronic inflammatory lung diseases impact more than 300 million of people worldwide. Because they are not curable, these diseases have a high impact on both the quality of life of patients and the healthcare budget. The stability of patient condition relies mostly on constant treatment adaptation and lung function monitoring. However, due to the variety of inflammation phenotypes, almost one third of the patients receive an ineffective treatment. To improve phenotyping, we evaluated the complementarity of two techniques for exhaled breath analysis: full resolving comprehensive two-dimensional gas chromatography coupled to high-resolution time-of-flight mass spectrometry (GC × GC-HRTOFMS) and rapid screening selected ion flow tube MS (SIFT-MS). GC × GC-HRTOFMS has a high resolving power and offers a full overview of sample composition, providing deep insights on the ongoing biology. SIFT-MS is usually used for targeted analyses, allowing rapid classification of samples in defined groups. In this study, we used SIFT-MS in a possible untargeted full-scan mode, where it provides pattern-based classification capacity. We analyzed the exhaled breath of 50 asthmatic patients. Both techniques provided good classification accuracy (around 75%), similar to the efficiency of other clinical tools routinely used for asthma phenotyping. Moreover, our study provides useful information regarding the complementarity of the two techniques.

Composite type-2 biomarker strategy versus a symptom-risk-based algorithm to adjust corticosteroid dose in patients with severe asthma: a multicentre, single-blind, parallel group, randomised controlled trial

BACKGROUND

Asthma treatment guidelines recommend increasing corticosteroid dose to control symptoms and reduce exacerbations. This approach is potentially flawed because symptomatic asthma can occur without corticosteroid responsive type-2 (T2)-driven eosinophilic inflammation, and inappropriately high-dose corticosteroid treatment might have little therapeutic benefit with increased risk of side-effects. We compared a biomarker strategy to adjust corticosteroid dose using a composite score of T2 biomarkers (fractional exhaled nitric oxide [FENO], blood eosinophils, and serum periostin) with a standardised symptom-risk-based algorithm (control).

METHODS

We did a single-blind, parallel group, randomised controlled trial in adults (18-80 years of age) with severe asthma (at treatment steps 4 and 5 of the Global Initiative for Asthma) and FENO of less than 45 parts per billion at 12 specialist severe asthma centres across England, Scotland, and Northern Ireland. Patients were randomly assigned (4:1) to either the biomarker strategy group or the control group by an online electronic case-report form, in blocks of ten, stratified by asthma control and use of rescue systemic steroids in the previous year. Patients were masked to study group allocation throughout the entirety of the study. Patients attended clinic every 8 weeks, with treatment adjustment following automated treatment-group-specific algorithms: those in the biomarker strategy group received a default advisory to maintain treatment and those in the control group had their treatment adjusted according to the steps indicated by the trial algorithm. The primary outcome was the proportion of patients with corticosteroid dose reduction at week 48, in the intention-to-treat (ITT) population. Secondary outcomes were inhaled corticosteroid (ICS) dose at the end of the study; cumulative dose of ICS during the study; proportion of patients on maintenance oral corticosteroids (OCS) at study end; rate of protocol-defined severe exacerbations per patient year; time to first severe exacerbation; number of hospital admissions for asthma; changes in lung function, Asthma Control Questionnaire-7 score, Asthma Quality of Life Questionnaire score, and T2 biomarkers from baseline to week 48; and whether patients declined to progress to OCS. A secondary aim of our study was to establish the proportion of patients with severe asthma in whom T2 biomarkers remained low when corticosteroid therapy was decreased to a minimum ICS dose. This study is registered with ClinicalTrials.gov, NCT02717689 and has been completed.

FINDINGS

Patients were recruited from Jan 8, 2016, to July 12, 2018. Of 549 patients assessed, 301 patients were included in the ITT population and were randomly assigned to the biomarker strategy group (n=240) or to the control group (n=61). 28·4% of patients in the biomarker strategy group were on a lower corticosteroid dose at week 48 compared with 18·5% of patients in the control group (adjusted odds ratio [aOR] 1·71 [95% CI 0·80-3·63]; p=0·17). In the per-protocol (PP) population (n=121), a significantly greater proportion of patients were on a lower corticosteroid dose at week 48 in the biomarker strategy group (30·7% of patients) compared with the control group (5·0% of patients; aOR 11·48 [95% CI 1·35-97·83]; p=0·026). Patient choice to not follow treatment advice was the principle reason for loss to PP analysis. There was no difference in secondary outcomes between study groups and no loss of asthma control among patients in the biomarker strategy group who reduced their corticosteroid dose.

INTERPRETATION

Biomarker-based corticosteroid adjustment did not result in a greater proportion of patients reducing corticosteroid dose versus control. Understanding the reasons for patients not following treatment advice in both treatment strategies is an important area for future research. The prevalence of T2 biomarker-low severe asthma was low.

FUNDING

This study was funded, in part, by the Medical Research Council UK.

Sputum quantitative cytometry in patients with interstitial lung disease and chronic cough

BACKGROUND

Chronic cough frequently occurs in patients with diffuse interstitial lung diseases (ILDs), and can have negative effects on quality-of-life. While there are multiple possible contributors to cough in this setting, the contribution and consequences of airway inflammation have not been previously measured. We aimed to estimate the prevalence of airway cellular inflammation in patients with chronic cough and ILD, and examine the interaction between airway inflammation and changes in lung function.

METHODS

We examined all patients with physician-diagnosed ILD and chronic cough who had sputum quantitative cytometry ordered between 2004 and 2018. The prevalence of airway inflammation was estimated by applying previously established criteria for bronchitis. FEV₁ and FVC were compared between individuals based on the presence of airway inflammation. The changes in FEV₁ and FVC were compared between individuals who had their treatment tailored to their sputum result, and those who did not.

RESULTS

Airway inflammation was present in 50% of patients (n = 173), and was associated with lower FEV₁ (1.87 vs 2.05 L, p = 0.043) and FVC (2.39 vs 2.71, p = 0.024). Sputum-guided management of airway eosinophilia was associated with improvements in FEV₁ (+120 vs -205mL, p < 0.0001) and stability of FVC (+13 vs -284mL, p = 0.003).

CONCLUSIONS

Airway inflammation is common in patients with chronic cough and ILD, and its presence may negatively affect lung function. Further research is required to understand if there is a role for quantitative sputum cytometry in this population, particularly if sputum-guided management of airway inflammation could lead to improvements in cough and other ILD outcomes.

Serum prednisolone levels as a marker of oral corticosteroid adherence in severe asthma

Background

Severe asthma is a complex heterogeneous disease typically requiring advanced therapies. Underlying the treatment of all asthma, however, is the consistent recommendation across international guidelines to ensure that adherence to therapy is adequate. Currently, there is no consensus on an objective marker of adherence.

Methods

We performed a prospective observational study of 17 participants taking oral prednisolone using serum prednisolone levels as a marker of adherence, and sputum eosinophilia as a marker of control of type 2 airway inflammation. Based on these biomarkers, we classified participants into a non-adherent and an adherent cohort, and further stratified by the presence of ongoing sputum eosinophilia.

Results

We identified 3 non-adherent participants and 14 who were adherent, based on their serum prednisolone levels. Stratification using sputum eosinophil counts identified one participant as having ongoing sputum eosinophilia in the setting of non-adherence, while six were identified as steroid resistant with ongoing sputum eosinophilia despite adherence to oral prednisolone therapy.

Conclusion

Serum prednisolone can be used an objective marker of adherence in those patients with severe asthma taking daily oral prednisolone. In combination with sputum eosinophil counts, a steroid resistant cohort can be distinguished from one with ongoing inflammation in the setting of non-adherence. This information can then be used by clinicians to differentiate the optimal next steps for treatment in these specific populations.

Trial registration

Participants were recruited as part of the Markers of Inflammation in the Management of Severe Asthma (MIMOSA) study, trial registration ACTRN12616001015437, 02 August 2016.

Towards a personalised treatment approach for asthma attacks

Asthma attacks (exacerbations) are common, accounting for over 90 000 UK hospital admissions per annum. They kill nearly 1500 people per year in the UK, have significant associated direct and indirect costs and lead to accelerated and permanent loss of lung function. The recognition of asthma as a heterogeneous condition with multiple phenotypes has revolutionised the approach to the long-term management of the condition, with greater emphasis on personalised treatment and the introduction of the treatable traits concept. In contrast asthma attacks are poorly defined and understood and our treatment approach consists of bronchodilators and systemic corticosteroids. This review aims to explore the current limitations in the description, assessment and management of asthma attacks. We will outline the risk factors for attacks, strategies to modify this risk and describe the recognised characteristics of attacks as a first step towards the development of an approach for phenotyping and personalising the treatment of these critically important events. By doing this, we hope to gradually improve asthma attack treatment and reduce the adverse effects associated with recurrent courses of corticosteroids.

Advances with glucocorticoids in the treatment of asthma: state of the art

INTRODUCTION

Asthma is one of the most frequent chronic diseases all over the world. Glucocorticoids (GCs), both inhaled (ICSs) and oral (OCSs), are the most effective treatment in asthma because they control symptoms and prevent exacerbations.

AREAS COVERED

The present article reviews the new therapeutic indications of GCs for the treatment of asthma and focuses on new molecules and safety issues.

EXPERT OPINION

Most patients with asthma benefit from corticosteroid-based treatments. Side effects are mainly due to prolonged use of oral GCs, while they are minor with inhaled GCs. Interesting insights come from the new ICSs, which are characterized by lower oral bioavailability and higher lipophilicity and are more effective with less side effects. Recent trials have shown the efficacy of early use of ICSs in mild asthma. Furthermore, the possibility to prescribe targeted therapies using specific biomarkers in steroid-sensitive asthma can reduce doses and duration of treatment, while biological agents should be reserved for non-responding patients. All this evidence confirm the need to continue on the path toward precision medicine, in which the treatments are based on clinical and molecular traits.

Association between biomarkers and house dust mite sublingual immunotherapy in allergic asthma

BACKGROUND

House dust mite (HDM) sublingual immunotherapy (SLIT) has demonstrated efficacy in clinical trials of patients with asthma. Airway inflammation is a characteristic of respiratory allergy, but its relationship to SLIT remains unclear.

OBJECTIVE

We evaluate the association between clinical outcomes with pulmonary function and biomarkers in before and after HDM SLIT (UMIN Number 000022390).

METHODS

One hundred twelve patients with asthma sensitized to HDM were randomized to add-on 6 standardized quality (SQ)-HDM SLIT to pharmacotherapy or pharmacotherapy alone for 48 weeks. At baseline and end of study, biomarkers, blood eosinophils, serum IgE, serum periostin, fractional exhaled nitric oxide (FeNO), and spirometry and clinical symptoms were measured. Association between biomarkers and an increase in FEV₁ of 120 mL or greater were analysed.

RESULTS

Sublingual immunotherapy (SLIT) demonstrated a significant reduction of serum periostin (P < .001), FeNO (P < .01), and increase in HDM-specific IgE (P < .05), FEV₁ (P < .001) and improvement of clinical symptom scores, when compared to pharmacotherapy. The change in FEV₁ correlated with the changes in serum periostin (r = .696, P < .001) and the changes in FeNO (r = .682, P < .001). The independent predictor of improvement in airflow limitation was changed in serum periostin (r²  = .753, P = .013) and FeNO (P = .038). Based on cut-off values derived by receiver operating characteristic analysis (periostin 30.9 ng/mL, FeNO 28.0 ppb), patients were distinguished responders from non-responders, but with no predictive value for blood eosinophils or total IgE. The proportion of patients with both high periostin and FeNO levels was significantly higher in responder than in non-responder (P = .026).

CONCLUSIONS AND CLINICAL RELEVANCE

Adding HDM SLIT to pharmacotherapy resulted in reduced serum periostin and FeNO, and improved pulmonary function. Serum periostin and FeNO may be useful biomarkers for prediction of SLIT.

Variability in airway inflammation, symptoms, lung function and reliever use in asthma: anti-inflammatory reliever hypothesis and STIFLE study design

Asthma is a chronic inflammatory airway disease. Increase in airway inflammation is hypothesised to contribute to worsening of asthma symptoms and deterioration in lung function, resulting in the use of reliever medication. Short-acting β₂-agonists only treat the symptoms, whereas an anti-inflammatory reliever is believed to treat both symptoms and the underlying inflammation, thereby arresting the progression to an exacerbation. As-needed budesonide/formoterol as an anti-inflammatory reliever reduces the risk of severe exacerbations. However, supporting mechanistic evidence has not yet been described, specifically the temporal dynamics of parameters including airway inflammation, over time and during asthma worsening. The STIFLE study aims to characterise daily variability in airway inflammation, symptoms, lung function and reliever use in people with asthma. This phase IV, open-label, parallel-group, multicentre, exploratory study will enrol 60-80 adult patients with asthma receiving low- or medium-dose inhaled corticosteroids/long-acting β₂-agonists (EudraCT identifier number 2018-003467-64). Participants will be randomised 1:1 to either as-needed budesonide/formoterol dry-powder inhaler or salbutamol reliever for 24 weeks, in addition to their maintenance therapy. Daily data will be captured for fractional exhaled nitric oxide, spirometry, asthma symptoms and medication use using devices connected to a smartphone via the STIFLE application. STIFLE will thereby enable not only characterisation of the variability of airway inflammation and clinical outcomes in relation to asthma worsening, but also elucidate the effect of as-needed budesonide/formoterol on airway inflammation against a background of daily maintenance therapy.

Serum Eosinophil-Derived Neurotoxin Better Reflect Asthma Control Status Than Blood Eosinophil Counts

BACKGROUND

Although several biomarkers have been proposed for eosinophilic asthma, biomarkers for reflecting asthma control status remain controversial. Eosinophil-derived neurotoxin (EDN), a degranulated eosinophil protein, is an emerging biomarker in asthmatic patients.

OBJECTIVE

This study analyzed serum EDN concentrations in asthmatics and compared its performance with that of blood eosinophil count as an indicator of asthma control status.

METHODS

We enrolled 75 uncontrolled asthmatics, 56 controlled asthmatics, and 43 healthy controls from Asan Medical Center. Serum EDN levels (ng/mL) were measured using an enzyme-linked immunosorbent assay kit. The predictability of EDN for asthma control status was analyzed by univariate and multivariable logistic regression analyses. A receiver operating characteristic (ROC) curve analysis was conducted to compare the performances of a serum EDN level and blood eosinophil count as indicators of uncontrolled asthma status.

RESULTS

The mean serum EDN level in the uncontrolled asthma group was higher than that in the controlled asthma and healthy groups (103.2 ± 60.2 vs 60.8 ± 49.7 vs 49.6 ± 28.3 ng/mL, P < .001). Serum EDN level was the significant parameter related to asthma control status in univariate and multivariable analysis (both P < .001). Serum EDN levels correlated with blood eosinophil counts (r = 0.510, P < .001). However, in the ROC analysis, serum EDN level showed a significantly better performance for predicting uncontrolled asthma status (area under the curve, 0.726 vs 0.628, P = .024).

CONCLUSIONS

Serum EDN levels significantly differed between patients with controlled and uncontrolled status in adult asthmatics. To our knowledge, this is the first study to identify EDN as a better indicator of asthma control status than blood eosinophil count.

A prenatally disrupted airway epithelium orchestrates the fetal origin of asthma in mice

BACKGROUND

Prenatal challenges such as maternal stress perception increase the risk and severity of asthma during childhood. However, insights into the trajectories and targets underlying the pathogenesis of prenatally triggered asthma are largely unknown. The developing lung and immune system may constitute such targets.

OBJECTIVE

Here we have aimed to identify the differential sex-specific effects of prenatal challenges on lung function, immune response, and asthma severity in mice.

METHODS

We generated bone marrow chimeric (BMC) mice harboring either prenatally stress-exposed lungs or a prenatally stress-exposed immune (hematopoietic) system and induced allergic asthma via ovalbumin. Next-generation sequencing (RNA sequencing) of lungs and assessment of airway epithelial barrier function in ovalbumin-sensitized control and prenatally stressed offspring was also performed.

RESULTS

Profoundly enhanced airway hyperresponsiveness, inflammation, and fibrosis were exclusively present in female BMC mice with prenatally stress-exposed lungs. These effects were significantly perpetuated if both the lungs and the immune system had been exposed to prenatal stress. A prenatally stress-exposed immune system alone did not suffice to increase the severity of these asthma features. RNA sequencing analysis of lungs from prenatally stressed, non-BMC, ovalbumin-sensitized females unveiled a deregulated expression of genes involved in asthma pathogenesis, tissue remodeling, and tight junction formation. It was also possible to independently confirm a tight junction disruption. In line with this, we identified an altered perinatal and/or postnatal expression of genes involved in lung development along with an impaired alveolarization in female prenatally stressed mice.

CONCLUSION

Here we have shown that the fetal origin of asthma is orchestrated by a disrupted airway epithelium and further perpetuated by a predisposed immune system.

Predictive value of blood eosinophils and exhaled nitric oxide in adults with mild asthma: a prespecified subgroup analysis of an open-label, parallel-group, randomised controlled trial

BACKGROUND

Whether blood eosinophil counts and exhaled nitric oxide (FeNO) are associated with important outcomes in mild asthma is unclear. In this prespecified subgroup analysis of a previously published open-label clinical trial, we aimed to assess associations between blood eosinophil counts and FeNO with outcomes and response to asthma treatment.

METHODS

In the previously reported 52-week, open-label, randomised controlled trial, people with mild asthma receiving only β agonist reliever inhalers were enrolled at one of 16 clinical trials units in New Zealand, the UK, Italy, or Australia. Eligible participants were randomly assigned (1:1:1, stratified by country), to receive inhalers to take as-needed salbutamol (two inhalations of 100 μg in a pressurised metered dose inhaler), maintenance budesonide (200 μg twice per day by inhaler) plus as-needed salbutamol (two inhalations of 100 μg), or as-needed budesonide-formoterol (one inhalation of 200 μg budesonide and 6μg formoterol by inhaler). The primary outcome was the annual rates of asthma exacerbations per patient, and in this prespecified subgroup analysis, we assessed whether annual exacerbation rates in each treatment group were significantly different depending on levels of blood eosinophil count, FeNO, or a composite score of both. Analyses were done for patients with available biomarker measurements The study was registered with the Australian New Zealand Clinical Trials Registry, number ACTRN12615000999538.

FINDINGS

675 participants were enrolled between March 17, 2016, and Aug 29, 2017, of whom 656 had results for blood eosinophil analysis and 668 had results for FeNO. Of the patients who received as-needed salbutamol, the proportion of patients having a severe exacerbation increased progressively with increasing blood eosinophil count (two [4%] of 49 participants with <0·15 × 10⁹/L, six [6%] of 93 with 0·15 to <0·3 × 10⁹/L, and 15 [19%] of 77 with ≥0·3 × 10⁹/L; p=0·014). There were no significant interactions between blood eosinophil count or FeNO level and the effect of as-needed budesonide-formoterol compared with as-needed salbutamol for either exacerbations or severe exacerbations. However, there were significant interactions between blood eosinophil count subgroups and the effect of maintenance budesonide plus as-needed salbutamol compared with as-needed salbutamol, both for exacerbations (p=0·0006) and severe exacerbations (p=0·0007). Maintenance budesonide plus as-needed salbutamol was more effective than as-needed salbutamol in patients with blood eosinophil counts of 0·3 × 10⁹/L or more, both for exacerbations (rate ratio 0·13 [95% CI 0·05-0·33]) and severe exacerbations (risk odds ratio 0·11 [0·03-0·45]). This difference was not seen for blood eosinophil counts of less than 0·15 × 10⁹/L (1·15 [0·51-1·28] for exacerbations and 5·72 [0·97-33·60] for severe exacerbations). There was no consistent interaction between treatment response and FeNO or the composite score.

INTERPRETATION

In patients with mild asthma, the effects of as-needed budesonide-formoterol on exacerbations are independent of biomarker profile, whereas the benefits of maintenance inhaled budesonide are greater in patients with high blood eosinophil counts than in patients with low counts.

FUNDING

AstraZeneca, Health Research Council of New Zealand.