Improving the diagnosis of eosinophilic asthma

Novel Serum Biomarkers for Patients with Allergic Asthma Phenotype

In distinguishing the allergic asthma (AA) phenotype, it has been identified that specific biomarkers could assist; however, none of them are considered ideal. This study aimed to analyze three groups of biologically active substances in the serum. Twenty steroid-free AA patients, sensitized to Dermatophagoides pteronyssinus, and sixteen healthy subjects (HSs) were enrolled in this study. Blood samples were collected from all patients. Additionally, all AA patients underwent a bronchial allergen challenge (BAC) with Dermatophagoides pteronyssinus, all of which were positive, and blood samples were collected again 24 h later. The concentrations of ten biologically active substances were measured in the serum samples, using enzyme-linked immunosorbent assay (ELISA) and the Luminex® 100/200™ System technology for bead-based multiplex and singleplex immunoassays. Descriptive and analytical statistical methods were used. A p-value of 0.05 or lower was considered statistically significant. The soluble interleukin 5 receptor subunit alpha (sIL-5Rα) and thioredoxin 1 (TRX1) concentrations were significantly increased, whereas those of tyrosine-protein kinase Met (MET), pentraxin 3 (PTX3), and I C-telopeptide of type I collagen (ICTP) were decreased in the AA group compared with the HS group. A significant positive correlation was noted for sIL-5Rα with fractional exhaled nitric oxide (FeNO), blood eosinophil (EOS) count, and total immunoglobulin E (IgE) levels, and a negative correlation was noted with forced expiratory volume in 1 s (FEV1). Moreover, PTX3 showed negative correlations with blood EOS count and total IgE levels, whereas ICTP exhibited a negative correlation with the blood EOS count. In conclusion, this study demonstrated that the serum concentrations of MET, PTX3, TRX1, ICTP, and particularly sIL-5Rα could potentially serve as biomarkers of the AA phenotype.

Asthma Inflammatory Phenotypes: How Can We Distinguish Them?

BACKGROUND AND OBJECTIVES

induced sputum is used to assess different inflammatory phenotypes in asthma, but is not used routinely. We aimed to determine the proportion of inflammatory asthma phenotypes based on induced sputum, to find biomarkers that can discriminate between phenotypes, and to evaluate biomarkers in patients with and without biological therapy in different inflammatory asthma phenotypes.

MATERIALS AND METHODS

this cross-sectional study investigated clinical characteristics, asthma control tests, skin prick test, impulse oscillometry (IOS), spirometry, induced sputum, biomarkers (IgE, eosinophils, fractional exhaled nitric oxide (FeNO), serum periostin, IL-5, IL-6, IL-8, IL-17A, IL-33) in 80 asthmatics. A total of 17/80 patients were treated with biologics (10 with omalizumab, 7 with benralizumab).

RESULTS

a total of 31% of patients had eosinophilic asthma (EA), 30% had mixed granulocytic asthma (MGA), 24% had paucigranulocytic asthma (PGA), and 15% had neutrophilic asthma (NA). The difference was found in blood eosinophils (p = 0.002), the highest observed in EA. The cut-off ≥ 240/μL eosinophils, with 64% sensitivity and 72.7% specificity, identified EA (AUC = 0.743, p = 0.001). A higher IL-8 level was associated with NA (p = 0.025). In 63 non-biologic asthma group, eosinophils were higher in EA than in NA, MGA, and PGA (p = 0.012, p = 0.028, and p = 0.049, respectively). A higher IL-17A was associated with EA without biologics (p = 0.004). A significantly higher IL-5 was found in EA treated with biologics, in comparison with EA without biologics (p = 0.043). The number of leucocytes and neutrophils was higher in MGA without biologics (p = 0.049, p = 0.019), while IL-5, IL-6, and IL-8 levels were higher in MGA treated with biologics (p = 0.012, p = 0.032, p = 0.038, respectively).

CONCLUSIONS

EA and MGA were the most prevalent asthma phenotypes. Blood eosinophils can identify EA, both in patients with and without biologics. Apart from the clinical profile, a broad spectrum of biomarkers for assessing inflammatory phenotypes is necessary for an adequate therapy approach to patients with asthma.

The Correlation Between Fractional Exhaled Nitric Oxide (FeNO), Blood Eosinophil Count, Immunoglobulin E Levels, and Spirometric Values in Patients With Asthma

BACKGROUND AND OBJECTIVE

In patients with asthma, fractional exhaled nitric oxide (FeNO) is a biomarker for eosinophilic airway inflammation. However, the correlation with the blood eosinophil count, immunoglobulin E (IgE), and spirometric values is not well established. We aimed to investigate the correlation between FeNO, blood eosinophils, IgE, and spirometric values in asthmatic patients.

METHODS

Data were extracted from the electronic medical records of adult asthmatic patients, and included the FeNO, blood eosinophil count, IgE, and spirometric values. The correlation between the markers was investigated using receiver operating characteristics (ROC) and the area under the curve (AUC).

RESULTS

A total of 135 adult patients (30% male) were analyzed. The mean FeNO was 36 ppb and almost half (48%) had a FeNO > 25 ppb. The mean blood eosinophil count was 377 cells/mm³, and 42% had a blood eosinophil count > 300 cells/mm³. There was a significant positive correlation between FeNO and the blood eosinophil count (r = 0.42, sensitivity 63%, specificity 77%, AUC 72%, p < 0.0001) as well as with the IgE (r = 0.35, sensitivity 78%, specificity 44%, AUC 68%, p < 0.0007). There was significant negative correlation between FeNO and FEV1% (r = -0.18, sensitivity 35%, specificity 85%, AUC 67%, p = 0.027).

CONCLUSION

The blood eosinophil count, IgE, and spirometric values were correlated with the severity of the eosinophilic airway inflammation (high FeNO). Asthmatic patients with a higher FeNO level had a higher eosinophil count, higher IgE levels, and lower FEV1 values.

A pathogenic integrated view explaining the different endotypes of asthma and allergic disorders

The inflammation of allergic diseases is characterized by a complex interaction between type 2 and type 3 immune responses, explaining clinical symptoms and histopathological patterns. Airborne stimuli activate the mucosal epithelium to release a number of molecules impacting the activity of resident immune and environmental cells. Signals from the mucosal barrier, regulatory cells, and the inflamed tissue are crucial conditions able to modify innate and adaptive effector cells providing the selective homing of eosinophils or neutrophils. The high plasticity of resident T- and innate lymphoid cells responding to external signals is the prerequisite to explain the multiplicity of endotypes of allergic diseases. This notion paved the way for the huge use of specific biologic drugs interfering with pathogenic mechanisms of inflammation. Based on the response of the epithelial barrier, the activity of resident regulatory cells, and functions of structural non-lymphoid environmental cells, this review proposes some immunopathogenic scenarios characterizing the principal endotypes which can be associated with a precise phenotype of asthma. Recent literature indicates that similar concepts can also be applied to the inflammation of other non-respiratory allergic disorders. The next challenges will consist in defining specific biomarker(s) of each endotype allowing for a quick diagnosis and the most effective personalized therapy.

The use of remote video directly observed therapy to improve both inhaler technique and adherence to asthma medications

Incorrect inhaler technique and non-adherence to inhaled preventer therapy often is the cause of poorly controlled asthma. Detecting and correcting non-adherence in asthma therapy has proven difficult. In addition, while patients may be able to demonstrate correct inhaler technique at the clinic recent evidence suggests that critical errors in inhaler technique occur in the home setting. Remote video directly observed therapy (vDOT) has recently been described as a potentially useful tool for addressing non-adherence while also allowing timely correction of inhaler technique errors. In this mini-review we describe the use of vDOT in asthma management.

Severe asthma treatment patterns: A multicenter observational study in the Gulf region

Background

Methods

Results

Conclusions

Aberrant Methylation of Aging-Related Genes in Asthma

Background: Asthma is a complex pulmonary inflammatory disease which is common among older adults. Aging-related alterations have also been found in structural cells and immune cells of asthma patients. Nonetheless, the underlying mechanism by which differenced aging-related gene contributes to asthma pathology remains unclear. Of note, DNA methylation (DNAm) has been proven to play a critical mechanism for age-related gene expression changes. However, the methylation changes of aging-related genes in asthma patients are still obscure.

Methods: First, changes in DNAm and gene expression were detected with multiple targeted bisulfite enrichment sequencing (MethTarget) and qPCR in peripheral blood of 51 healthy controls (HCs) and 55 asthmatic patients. Second, the correlation between the DNAm levels of specific altered CpG sites and the pulmonary function indicators of asthma patients was evaluated. Last, the receiver operator characteristic (ROC) curve and principal component analysis (PCA) were used to identify the feasibility of the candidate CpG sites as biomarkers for asthma.

Results: Compared with HCs, there was a differential mRNA expression for nine aging-related genes in peripheral blood of asthma patients. Besides, the methylation levels of the nine aging-related genes were also altered in asthma patients, and a total of 68 CpG sites were associated with the severity of asthma. Notably, 9 of the 68 CpG sites were significantly associated with pulmonary function parameters. Moreover, ROC curve and PCA analysis showed that the candidate differential methylation sites (DMSs) can be used as potential biomarkers for asthma.

Conclusions: In summary, this study confirmed the differentially expressed mRNA and aberrant DNAm level of aging-related genes in asthma patients. DMSs are associated with the clinical evaluation indicators of asthma, which indicate the involvement of aging-related genes in the pathogenesis of asthma and provide some new possible biomarkers for asthma.

Molecular Analysis of IL-5 Receptor Subunit Alpha as a Possible Pharmacogenetic Biomarker in Asthma

Background: Asthma is a heterogeneous syndrome with a broad clinical spectrum and high drug response variability. The inflammatory response in asthma involves multiple effector cells and mediator molecules. Based on asthma immunopathogenesis, precision medicine can be a promising strategy for identifying biomarkers. Biologic therapies acting on the IL-5/IL-5 receptor axis have been developed. IL-5 promotes proliferation, differentiation and activation of eosinophils by binding to the IL-5 receptor, located on the surface of eosinophils and basophils. This study aimed to investigate the expression of IL5RA in patients with several types of asthma and its expression after treatment with benralizumab, a biologic directed against IL-5 receptor subunit alpha.

Methods: Sixty peripheral blood samples, 30 from healthy controls and 30 from asthmatic patients, were selected for a transcriptomic RNAseq study. Differential expression analysis was performed by statistical assessment of fold changes and P-values. A validation study of IL5RA expression was developed using qPCR in 100 controls and 187 asthmatic patients. The effect of benralizumab on IL5RA expression was evaluated in five patients by comparing expression levels between pretreatment and after 3 months of treatment. The IL5RA mRNA levels were normalized to GAPDH and TBP expression values for each sample. Calculations were made by the comparative ΔΔCt method. All procedures followed the MIQE guidelines.

Results:IL5RA was one of the most differentially overexpressed coding transcripts in the peripheral blood of asthmatic patients (P = 8.63E-08 and fold change of 2.22). In the qPCR validation study, IL5RA expression levels were significantly higher in asthmatic patients than in controls (P < 0.001). Significant expression differences were present in different asthmatic types. In the biological drug study, patients treated with benralizumab showed a significant decrease in IL5RA expression and blood eosinophil counts. A notable improvement in ACT and lung function was also observed in these patients.

Conclusions: These results indicate that IL5RA is overexpressed in patients with different types of asthma. It could help identify which asthmatic patients will respond more efficiently to benralizumab, moving toward a more personalized asthma management. Although further studies are required, IL5RA could play a role as a biomarker and pharmacogenetic factor in asthma.

Asthma and Obesity: Two Diseases on the Rise and Bridged by Inflammation

Asthma and obesity are two epidemics affecting the developed world. The relationship between obesity and both asthma and severe asthma appears to be weight-dependent, causal, partly genetic, and probably bidirectional. There are two distinct phenotypes: 1. Allergic asthma in children with obesity, which worsens a pre-existing asthma, and 2. An often non allergic, late-onset asthma developing as a consequence of obesity. In obesity, infiltration of adipose tissue by macrophages M1, together with an increased expression of multiple mediators that amplify and propagate inflammation, is considered as the culprit of obesity-related inflammation. Adipose tissue is an important source of adipokines, such as pro-inflammatory leptin, produced in excess in obesity, and adiponectin with anti-inflammatory effects with reduced synthesis. The inflammatory process also involves the synthesis of pro-inflammatory cytokines such as IL-1β, IL-6, TNFα, and TGFβ, which also contribute to asthma pathogenesis. In contrast, asthma pro-inflammatory cytokines such as IL-4, IL-5, IL-13, and IL-33 contribute to maintain the lean state. The resulting regulatory effects of the immunomodulatory pathways underlying both diseases have been hypothesized to be one of the mechanisms by which obesity increases asthma risk and severity. Reduction of weight by diet, exercise, or bariatric surgery reduces inflammatory activity and improves asthma and lung function.

Mepolizumab Effectiveness and Allergic Status in Real Life

BACKGROUND

It is not clear whether mepolizumab is differently effective in allergic and nonallergic severe eosinophilic asthmatics (SEA) in real life.

OBJECTIVE

We tested mepolizumab effectiveness in allergic/nonallergic SEA in real life. A strict criterion to identify the 2 phenotypes was used.

METHOD

We retrospectively considered 134 consecutive patients divided into allergic, with a positivity to at least 1 allergen to prick tests and/or IgE values ≥100 UI/mL (severe allergic eosinophilic asthma [SAEA]; n: 97-72.4%), and nonallergic, with no prick test results and normal IgE levels <100 UI/mL (severe nonallergic eosinophilic asthma [SNAEA]; n: 37-27.6%). They had taken mepolizumab for at least 6 months.

RESULTS

After 10.9 ± 3.7 months, improvements in FEV1%, FEF25-75%, exacerbation numbers, blood eosinophil (BE) counts, fractional exhaled nitric oxide (FENO) (ppb), percentages of patients that stopped/reduced short-acting β2-agonists (SABAs) or oral corticosteroid (OC), observed after treatment, were similar in both groups. Only Asthma Control Test (ACT) increases were higher in SNAEA (8 [5-9]) than in SAEA (5 [2.5-8.5]; p = 0.016). However, no differences were found after treatment in percentages of subjects with ACT ≥20, as well as with FEV1 >80%, FEF25-75 >65%, exacerbations ≤2, BE <300 cells/µL, and FENO <25 ppb between SAEA and SNAEA. Besides, no significant relationships were found, comparing SNAEA with SAEA, for FEV1% (β = -0.110; p = 0.266), FEF25-75% (β = -0.228; p = 0.06), BE counts (β = -0.012; p = 0.918), FENO (β = 0.234; p = 0.085), ACT (β = 0.046; p = 0.660), and exacerbations (β = -0.070; p = 0.437). No different associations between lung function and SNAEA occurrence when compared to SAEA condition (FEV1 >80%: OR = 1.04 [95% CI: 0.43-2.55], p = 0.923; FEF25-75 >65%: OR = 0.41 [95% CI: 0.08-2.03], p = 0.272) were detected. Neither all other parameters, such as ACT >20 (OR = 0.73 [95% CI: 0.32-1.63], p = 0.440), presence of exacerbations (OR = 1.35 [95% CI: 0.55-3.27], p = 0.512), SABA discontinuation (OR = 1.16 [95% CI: 0.40-3.39], p = 0.790), and OC cessation/reduction (OR = 3.44 [95% CI: 0.40-29.27], p = 0.258), were differently associated with 1 or the other phenotype.

CONCLUSION

Mepolizumab can be considered as a valid therapeutic choice for either allergic or nonallergic SEA in real life.

Phenotypes and endotypes of adult asthma: Moving toward precision medicine

Asthma is a chronic inflammatory disease of the airways that is challenging to dissect into subgroups because of the heterogeneity present across the spectrum of the disease. Efforts to subclassify asthma using advanced computational methods have identified a number of different phenotypes that suggest that multiple pathobiologically driven clusters of disease exist. The main phenotypes that have been identified include (1) early-onset allergic asthma, (2) early-onset allergic moderate-to-severe remodeled asthma, (3) late-onset nonallergic eosinophilic asthma, and (4) late-onset nonallergic noneosinophilic asthma. Subgroups of these phenotypes also exist but have not been as consistently identified. Advances in our understanding of the diverse immunologic perturbations that drive airway inflammation are consistent with clinical traits associated with these phenotypes and their response to biologic therapies. This has improved the clinician's approach to characterizing asthmatic patients in the clinic. Being able to define asthma endotypes using clinical characteristics and biomarkers will move physicians toward even more personalized management of asthma and precision-based care in the future. Here we will review the most prominent phenotypes and immunologic advances that suggest these disease subtypes represent asthma endotypes.

Blood eosinophil count group shifts and kinetics in severe eosinophilic asthma

BACKGROUND

Blood eosinophil count (BEC) measurements are a noninvasive, relatively reliable surrogate marker for eosinophilic airway inflammation. Single measurements of peripheral BEC greater than or equal to 150 cells/μL predict the response to anti-eosinophil therapies for patients with characteristics of severe eosinophilic asthma.

OBJECTIVE

To describe how BECs shift over time for patients with severe, uncontrolled asthma receiving placebo in 2 large, randomized, placebo-controlled clinical trials of benralizumab (SIROCCO and CALIMA).

METHODS

Our analysis included all adult patients who were randomized to placebo in the SIROCCO and CALIMA phase III benralizumab studies. Patients were categorized into baseline BEC groups of less than 150 cells/μL, greater than or equal to 150 cells/μL but less than 300 cells/μL, and greater than or equal to 300 cells/μL. The timing of the initial shift from baseline to a different group was evaluated at weeks 4, 8, 24, and 40 and at the end of treatment. Baseline characteristics, including oral corticosteroid use, were described based on the presence or absence of a BEC group shift.

RESULTS

Of the 734 evaluable patients, 65% (n = 474) shifted BEC groups during the study, and most patients (86% [n = 410]) shifted by week 24. Patients who started in the less than 150 cells/μL group tended to shift groups earlier, with 59% shifting by week 4 compared with 38% to 55% for other groups in the same time frame. Patients who shifted BEC groups vs those who did not tend to have lower BECs, more oral corticosteroid use, and less incidence of nasal polyps or past polypectomy.

CONCLUSION

A single BEC measurement, particularly when low, may be inadequate to help establish a phenotype of severe eosinophilic asthma.

TRIAL REGISTRATION

ClinicalTrials.gov Identifiers NCT01928771 (SIROCCO trial) and NCT01914757 (CALIMA trial).

Relationship between Particulate Matter (PM10) and Airway Inflammation Measured with Exhaled Nitric Oxide Test in Seoul, Korea

Purpose

Particulate matter (PM) is increasing every year in Asia. It is not fully understood how the airway is affected when inhaling PM. We investigated the correlation between particulate matter with a diameter of less than 10 μm (PM₁₀) and fractional exhaled nitric oxide (FeNO) to determine whether PM causes airway inflammation. Material and Methods. We analyzed patients who visited our outpatient clinic and tested FeNO from January 2016 to December 2017 at the Korea University Guro Hospital. PM₁₀ data were provided by the government of the Republic of South Korea, and measuring station of PM₁₀ is located 800 meters from the hospital. We analyzed the correlation between PM₁₀ and FeNO by a Pearson correlation analysis and by a multivariate linear regression analysis. To identify the most correlated times, we analyzed the correlation between the FeNO and PM₁₀ daily average from the day of visit to 4 days before visit.

Results

FeNO positively correlated with PM₁₀ at two days before hospital visit in the Pearson correlation (Pearson correlation coefficient = 0.057; P-value = 0.023) and in the multivariate linear regression analysis (B = 0.051, P-value = 0.026). If the PM₁₀ increased by 100 μg/m³, the FeNO result was expected to rise to 8.3 ppb in healthy people without respiratory disease.

Conclusion

The positive correlation was found in both healthy people and asthmatic patients. Therefore, PM₁₀ can increase airway inflammation.

Severe asthma: oral corticosteroid alternatives and the need for optimal referral pathways

OBJECTIVE

Patients with severe asthma require high-dose inhaled corticosteroids, with or without add-on treatments, to maintain asthma control. Because symptom control remains unsatisfactory in some patients despite these therapies, maintenance therapy with oral corticosteroids (OCS) remains considered a treatment option by physicians. Besides physician-diagnosed exacerbations, many patients intermittently self-medicate with OCS during episodes of worsening symptoms or as a prevention of such episodes. However, long-term OCS use is associated with several comorbidities that may decrease health-related quality of life, worsen prognosis, and should ideally require monitoring and management. In this review, we discuss the adverse effects of OCS use, the OCS-sparing effect of biologics in severe asthma, and the need for optimal referral pathways to ensure the best outcomes for those at-risk asthma patients.

DATA SOURCES

PubMed.

STUDY SELECTION

Studies with results on the OCS-sparing effect of biologics in adult severe asthma were selected.

RESULTS

Chronic and intermittent OCS use in asthma is associated with considerable adverse effects in asthma. Omalizumab, mepolizumab, benralizumab, and dupilumab reduce the need for OCS in severe asthma, while also reducing the exacerbation rate and improving several patient-related outcomes.

CONCLUSION

Targeted biologic therapies have revolutionized the treatment of uncontrolled severe asthma by reducing or even eliminating the need for OCS and improving other major outcomes. Novel agents are now rapidly increasing the therapeutic armamentarium, but additional efforts are needed to optimize referral pathways in order to ensure sustainable access to these therapies.

Suppression of F ENO with observed inhaled corticosteroid therapy in severe asthma: is it a useful test in clinical practice?

Biologic therapies are used in atopic and/or eosinophilic asthma that remains uncontrolled on optimised conventional therapy [1–4]. Nonadherence with prescribed therapy is common in severe asthma [5] and National Health Service England's commissioning guideline [6] advises adherence assessment prior to commencing biologic therapy.

F_ENO suppression testing is practical and feasible during assessment for biologics in severe asthma. Patients with significant F_ENO suppression were less likely to be recommended biologics but saw similar reductions in exacerbation frequency.http://bit.ly/35oSoxP

Cost-utility analysis of reslizumab for patients with severe eosinophilic asthma inadequately controlled with high-dose inhaled corticosteroids and long-acting β2-agonists in South Korea

Objectives: We aimed to assess the cost-utility of reslizumab for patients with severe eosinophilic asthma uncontrolled with high-dose inhaled corticosteroids and long-acting β₂-agonists (ICS/LABAs) in Korea.Methods: A Markov model with limited societal perspective was used to compare the costs and quality-adjusted life years (QALYs) of reslizumab add-on therapy with standard-of-care (high-dose ICS/LABA) and standard-of-care alone. The model adopted a 4 week cycle with the following six health states over a lifetime (60 years): controlled asthma, uncontrolled asthma, moderate exacerbation, severe exacerbation, all-cause death and asthma-related death. The population comprised adult patients (age ≥18 years) with severe eosinophilic asthma (eosinophils ≥400 cells/μL) at Global Initiative for Asthma (GINA) step 4 or 5 who had experienced at least three exacerbations in the preceding year. Model inputs were sourced from individual patient-level data from two 52 week randomized controlled trials of reslizumab (NCT01287039, NCT01285323). The model included discontinuation rules where patients uncontrolled with reslizumab add-on therapy were transitioned to the standard-of-care arm. Costs and QALYs were annually discounted at 5%. Deterministic and probabilistic sensitivity analyses were performed.Results: Reslizumab add-on therapy was associated with increased cost (US$119,394) and improved QALYs (5.17) compared with standard-of-care alone, resulting in an incremental cost-effectiveness ratio of US$23,081 per QALY gained. Body weight, time horizon and discount rate were influential factors in the model.Conclusions: The addition of reslizumab to high-dose ICS/LABA was cost-effective in Korean patients with severe eosinophilic asthma uncontrolled with high-dose ICS/LABA, based on the threshold of 1 gross domestic product in Korea.Trial registration: ClinicalTrials.gov identifier: NCT01285323.Trial registration: ClinicalTrials.gov identifier: NCT01287039.

Short-term pulmonary infiltrate with eosinophilia caused by asthma: a phenotype of severe, eosinophilic asthma? Five cases and a review of the literature

Background

Asthma is often accompanied by peripheral eosinophilia and eosinophilic airway inflammation. This article explores the relationship between asthma and short-term pulmonary infiltrate with eosinophilia, which results from irregular asthma treatment.

Case presentation

We report five unique cases of asthma-induced short-term eosinophilic pneumonia encountered at our pulmonary and critical care centre in Hunan, China, from January 1, 2014, to August 31, 2018. The 5 asthma patients were women with persistent dyspnoea symptoms, an increased peripheral eosinophil count and a high level of exhaled nitric oxide (FeNO). Chest CT revealed multiple infiltrates and ground-glass opacities in both lung fields in all 5 patients. Four of the 5 patients had increased eosinophils in bronchoalveolar lavage (BAL). Three were positive for reversibility in lung function testing, and two had eosinophil infiltration as revealed by lung biopsy. No antibiotic treatment was given, and after a short period of glucocorticoid therapy and inhaled corticosteroid plus long-acting β2-agonist (ICS + LABA) treatment, the symptoms of all of the patients disappeared. In addition, their blood eosinophils returned to normal, and their lung lesions were quickly absorbed and improved.

Conclusion

These cases show a unique association between short-term eosinophilic pneumonia and asthma. The occurrence of eosinophilic pneumonia can prove fatal during a serious asthma attack. Additionally, the presence of peripheral eosinophilia with lung infiltrates poses a diagnostic challenge for clinicians by creating suspicion of pulmonary infiltrate with eosinophilia when present in asthmatic patients.

Determinants of fractional exhaled nitric oxide in healthy men and women from the European Community Respiratory Health Survey III

INTRODUCTION

The fractional exhaled nitric oxide (F_E NO) is a marker for type 2 inflammation used in diagnostics and management of asthma. In order to use F_E NO as a reliable biomarker, it is important to investigate factors that influence F_E NO in healthy individuals. Men have higher levels of F_E NO than women, but it is unclear whether determinants of F_E NO differ by sex.

OBJECTIVE

To identify determinants of F_E NO in men and women without lung diseases.

METHOD

Fractional exhaled nitric oxide was validly measured in 3881 healthy subjects that had answered the main questionnaire of the European Community Respiratory Health Survey III without airways or lung disease.

RESULTS

Exhaled NO levels were 21.3% higher in men compared with women P < 0.001. Being in the upper age quartile (60.3-67.6 years), men had 19.2 ppb (95% CI: 18.3, 20.2) higher F_E NO than subjects in the lowest age quartile (39.7-48.3 years) P = 0.02. Women in the two highest age quartiles (54.6-60.2 and 60.3-67.6 years) had 15.4 ppb (14.7, 16.2), P = 0.03 and 16.4 ppb (15.6, 17.1), P = <0.001 higher F_E NO, compared with the lowest age quartile. Height was related to 8% higher F_E NO level in men (P < 0.001) and 5% higher F_E NO levels in women (P = 0.008). Men who smoked had 37% lower F_E NO levels and women had 30% lower levels compared with never-smokers (P < 0.001 for both). Men and women sensitized to both grass and perennial allergens had higher F_E NO levels compared with non-sensitized subjects 26% and 29%, P < 0.001 for both.

CONCLUSION AND CLINICAL RELEVANCE

Fractional exhaled nitric oxide levels were higher in men than women. Similar effects of current smoking, height, and IgE sensitization were found in both sexes. F_E NO started increasing at lower age in women than in men, suggesting that interpretation of F_E NO levels in adults aged over 50 years should take into account age and sex.

Variability of blood eosinophils in patients in a clinic for severe asthma

BACKGROUND

Blood eosinophils are used to determine eligibility for agents targeting IL-5 in patients with uncontrolled asthma. However, little is known about the variability of blood eosinophil measures in these patients before treatment initiation.

OBJECTIVE

To characterize variability and patterns of variability of blood eosinophil levels in a real-world clinic for severe asthmatics.

METHODS

Retrospective review of blood eosinophils measured over a 5-year period in patients enrolled in an urban clinic. Repeated measures of blood eosinophil levels in individuals were evaluated, and cluster analysis was performed to characterize patients by eosinophil patterns. Clinical characteristics associated with eosinophil levels and patterns of variability were analysed.

RESULTS

Patients treated in the Bellevue Hospital Asthma Clinic within a 3-month period were identified (n = 219). Blood eosinophil measures were obtained over the previous 5 years. Only 6% (n = 13) of patients had levels that were consistently above 300 cells/μL. Nearly 50% (n = 104) had eosinophil levels that traversed the threshold of 300 cells/μL. In contrast, 102 (46%) had levels that never reached the threshold of 300 cells/μL. Cluster analyses revealed three clusters with differing patterns of levels and variability. There was a suggestion of decreased clinical control and increased atopy in the cluster with the greatest variability in blood eosinophil measures.

CONCLUSION

In an urban clinic for patients referred for uncontrolled asthma, blood measures of eosinophils were variable and showed differing patterns of variability. These data reinforce the need to perform repeated eosinophil blood measures for appropriate designation for therapeutic intervention.

Identification and prospective stability of electronic nose (eNose)-derived inflammatory phenotypes in patients with severe asthma

BACKGROUND

Severe asthma is a heterogeneous condition, as shown by independent cluster analyses based on demographic, clinical, and inflammatory characteristics. A next step is to identify molecularly driven phenotypes using "omics" technologies. Molecular fingerprints of exhaled breath are associated with inflammation and can qualify as noninvasive assessment of severe asthma phenotypes.

OBJECTIVES

We aimed (1) to identify severe asthma phenotypes using exhaled metabolomic fingerprints obtained from a composite of electronic noses (eNoses) and (2) to assess the stability of eNose-derived phenotypes in relation to within-patient clinical and inflammatory changes.

METHODS

In this longitudinal multicenter study exhaled breath samples were taken from an unselected subset of adults with severe asthma from the U-BIOPRED cohort. Exhaled metabolites were analyzed centrally by using an assembly of eNoses. Unsupervised Ward clustering enhanced by similarity profile analysis together with K-means clustering was performed. For internal validation, partitioning around medoids and topological data analysis were applied. Samples at 12 to 18 months of prospective follow-up were used to assess longitudinal within-patient stability.

RESULTS

Data were available for 78 subjects (age, 55 years [interquartile range, 45-64 years]; 41% male). Three eNose-driven clusters (n = 26/33/19) were revealed, showing differences in circulating eosinophil (P = .045) and neutrophil (P = .017) percentages and ratios of patients using oral corticosteroids (P = .035). Longitudinal within-patient cluster stability was associated with changes in sputum eosinophil percentages (P = .045).

CONCLUSIONS

We have identified and followed up exhaled molecular phenotypes of severe asthma, which were associated with changing inflammatory profile and oral steroid use. This suggests that breath analysis can contribute to the management of severe asthma.

Eosinophils Target Therapy for Severe Asthma: Critical Points

Asthma is a chronic and heterogeneous disease, which is defined as severe disease whenever it requires treatment with a high dose of inhaled corticosteroids plus a second controller and/or systemic corticosteroids to prevent it from becoming ‘‘uncontrolled” or if it remains ‘‘uncontrolled” despite this therapy. Severe asthma is a heterogeneous condition consisting of phenotypes such as eosinophilic asthma, which is characterized by sputum eosinophilia, associated with mild to moderate increase in blood eosinophil count, frequently adult-onset, and associated with chronic rhinosinusitis with nasal polyps in half of the cases. Eosinophilic asthma is driven by T2 inflammation, characterized, among the others, by interleukin-5 production. IL-5 plays a key role in the differentiation, survival, migration, and activation of eosinophils, and it has become an appealing therapeutic target for eosinophilic asthma. In recent years two monoclonal antibodies (mepolizumab and reslizumab) directed against IL-5 and one monoclonal antibody directed against the alpha-subunit of the IL-5 receptor (benralizumab) have been developed. All these IL-5 target drugs have been shown to reduce the number of exacerbation in patients with severe asthma selected on the basis of peripheral blood eosinophil count. There are still a number of unresolved issues related to the anti-IL5 strategy in eosinophilic asthma, which are here reviewed. These issues include the effects of such therapy on airway obstruction and asthmatic symptoms, the level of baseline eosinophils that predicts a response to treatment, the relationship between blood and airway eosinophilia, and, perhaps most importantly, how to elucidate the pathogenetic role played by eosinophils in the individual patient with severe eosinophilic asthma.

A Charter to Improve Patient Care in Severe Asthma

Severe asthma is a subtype of asthma that is difficult to treat and control. By conservative estimates, severe asthma affects approximately 5–10% of patients with asthma worldwide. Severe asthma impairs patients’ health-related quality of life, and patients are at risk of life-threatening asthma attacks. Severe asthma also accounts for the majority of health care expenditures associated with asthma. Guidelines recommend that patients with severe asthma be referred to a specialist respiratory team for correct diagnosis and expert management. This is particularly important to ensure that they have access to newly available biologic treatments. However, many patients with severe asthma can suffer multiple asthma attacks and wait several years before they are referred for specialist care. As global patient advocates, we believe it is essential to raise awareness and understanding for patients, caregivers, health care professionals, and the public about the substantial impact of severe asthma and to create opportunities for improving patient care. Patients should be empowered to live a life free of symptoms and the adverse effects of traditional medications (e.g., oral corticosteroids), reducing hospital visits and emergency care, the loss of school and work days, and the constraints placed on their daily lives. Here we provide a Patient Charter for severe asthma, consisting of six core principles, to mobilize national governments, health care providers, payer policymakers, lung health industry partners, and patients/caregivers to address the unmet need and burden in severe asthma and ultimately work together to deliver meaningful improvements in care.

Funding: AstraZeneca.

Use of biomarkers to identify phenotypes and endotypes of severeasthma

OBJECTIVE

Severe asthma can be classified into phenotypes and endotypes, which may inform clinicians about inflammatory pathways leading to disease and ultimately guide optimal therapeutic strategy. Biomarkers, objectively measurable characteristics of the disease, are of increasing interest to clinicians and researchers as powerful tools to distinguish among the severe asthma phenotypes and endotypes. The objective of this review is to highlight current knowledge of biomarker applications to identify phenotypes and endotypes of severe asthma.

DATA SOURCES

Sources used include observational cohorts, clinical trials, translational studies, comprehensive reviews, and expert/taskforce statements.

STUDY SELECTIONS

Included studies were selected for their relevance to the topic and for strength of data or study design.

RESULTS

In severe asthma, biomarkers can be used for diagnosis of phenotype or endotype, can also be predictive of clinical outcomes or response to therapy, and may be dynamic with time or therapy. Fully determining phenotype or endotype of severe asthma will require interpretation of combinations of commercially available biomarkers.

CONCLUSION

Biomarkers have multiple potential clinical applications in severe asthma. Novel biomarkers may add accuracy to this field.

Asthma versus chronic obstructive pulmonary disease, the Dutch versus British hypothesis, and role of interleukin-5

PURPOSE OF REVIEW

Asthma and COPD represent heterogeneous disorders with broad ranging impact on patients and health systems. This review focuses on evidence for early attempts at understanding their pathogenesis by the British and Dutch hypotheses. It also addresses the role of eosinophils, IL-5, and biologics targeting these pathways in asthma and COPD.

RECENT FINDINGS

Among asthma and COPD patients, clusters exist based on phenotypic and biologic markers allowing for further understanding of endotypes. Recent studies suggest the role of eosinophils and optimal therapies for each condition may be different.

SUMMARY

Although patients with ACOS or overlap symptoms may be an exception, overall there appears to be more evidence supporting that asthma and COPD are distinct processes. Targeting eosinophils with anti-IL-5 therapy appears to be an exciting pathway in the properly selected patient with asthma and recent data also supports its use in COPD.

Update on new biologics for intractable eosinophilic asthma: impact of reslizumab

A small percentage of patients with asthma have uncontrolled symptoms and frequent exacerbations, despite treatment with inhaled corticosteroids and other agents. It has become clear that different subtypes of this severe, treatment-resistant group exist due to different mechanisms of the disease. All such patients require detailed assessment in specialist centers to characterize the disease and assess treatment adherence. Recently, monoclonal antibodies have become available, which target specific pathways that may contribute to persistent inflammation and asthma exacerbations. These antibodies include those targeting interleukin (IL)-5, which drives eosinophilic inflammation. Reslizumab is a newly licensed antibody that blocks binding of IL-5 to its receptor. Here, we discuss the significance of clinical data of this drug, which show up to 50% reduction in exacerbation rates, together with modest but significant improvements in lung function and quality of life, in those with persistent eosinophilia. The combination of reslizumab with mepolizumab and benralizumab, which also target IL-5, may be a useful addition to the therapeutic armamentarium in a selected group of patients with severe asthma.

Health care resource utilization and characteristics of patients with eosinophilic asthma in secondary health care in Finland

Background: Eosinophilic airway inflammation is common in asthma patients and appears to be associated with severe exacerbations and loss of asthma control. Objective: To describe the resource utilization and clinical characteristics of patients with eosinophilic asthma. Design: Asthma patients ≥18 years with ≥1 blood eosinophil count in secondary care (South West Finland) during 2003‒2013 were included. Clinical characteristics (age, lung function, body mass index, and comorbidities) and asthma-related resource utilization (hospital admissions, outpatient visits, and emergency room [ER] visits) were retrieved. Resource utilization rates were compared for patients with blood eosinophil ≤ or >300 cells/μL, using adjusted negative binomial regression models. Results: Overall, 4,357 eligible patients were identified (mean age 60 years, females 68%), of which 1,927 (44%) had >300 eosinophil cells/μL blood. Patients with ≤300 and >300 eosinophil counts, exhibited similar clinical characteristics, including advanced age, poor lung function, and overweight. Comorbidities such as pneumonia, sinusitis, and nasal polyps, were more frequent among those with >300 eosinophil cells/μL blood compared with patients with lower counts. Eosinophil counts >300 cells/μL were associated with greater hospital admissions (rate ratio [RR] [95% confidence interval CI]: 1.13 [1.02;1.24]) and outpatient visits (RR [95% CI]: 1.11 [1.03;1.20]) compared with patients with lower eosinophil counts. Rates of ER visits were similar between the patient groups (RR [95% CI]: 0.99 [0.87;1.12]). Conclusions: Hospital admissions and outpatient visits occurred more often for patients with eosinophil counts >300 cells/µL, than for patients with lower eosinophil counts. Routine blood eosinophil screening might be useful to identify patients with an eosinophilic phenotype eligible for more targeted treatments.

Biomarkers related to respiratory symptoms and lung function in adults with asthma

BACKGROUND

There is a need for easily measurable biomarkers that are able to identify different levels of asthma severity.

AIM

To assess the association between peripheral blood cell counts, fractional nitric oxide in exhaled air (FeNO), urinary biomarkers of oxidative stress (8-hydroxy-2'-deoxyguanosine and 8-isoprostane), and asthma severity in adult patients from the general population.

METHODS

In the Gene Environment Interactions in Respiratory Diseases study, 287 subjects with asthma (aged 20-64) were identified from the general population in Verona (Italy) (2008-2010). Self-reported asthma attacks, asthma-like symptoms and the use of hospital services in the past year were synthesized in a score of respiratory symptoms (SRS). The association of biomarkers with SRS and lung function measures (pre-bronchodilator FEV₁% predicted and FEV₁/FVC) was assessed using quasi-Poisson and Gaussian regression models, respectively.

RESULTS

Eosinophils (ratio of expected scores: RES[95%CI] = 1.19[1.09,1.30]), basophils (RES[95%CI] = 1.24[1.10,1.40]), lymphocytes (RES[95%CI] = 1.27[1.12,1.45]) and FeNO (RES[95%CI] = 1.18[1.02,1.37]) were positively associated with SRS. However, only eosinophils (RES[95%CI] = 1.15[1.02,1.30]) and lymphocytes (RES[95%CI] = 1.25[1.06,1.47]) showed an independent association. Furthermore, eosinophils (change in the expected outcome for 1-SD increase: CEO[95%CI] = -1.18[-2.09, -0.27]%), basophils (CEO[95%CI] = -1.24[-2.16, -0.33]%) and lymphocytes (CEO[95%CI] = -1.07[-1.99, -0.14]%) were individually, but not independently, associated with FEV₁/FVC. Finally, neutrophils were negatively associated with FEV₁% predicted (CEO[95%CI] = -2.22[-4.00, -0.44]%).

CONCLUSIONS

We identified a pattern of association between a set of biomarkers and asthma endotypes in adult patients from the general population, which could improve understanding of the heterogeneity and severity of the disease and could be useful in defining targeted therapeutic approaches.

Severe Asthma Phenotypes - How Should They Guide Evaluation and Treatment?

Although patients with "severe" asthma tend to be characterized by ongoing symptoms and airway inflammation despite treatment with high doses of inhaled and systemic corticosteroids, there is increasing recognition of marked phenotypic heterogeneity within affected patients. Although "precision medicine" approaches for patients with severe asthma are needed, there are many hurdles that must be overcome in daily practice. The National Heart, Lung and Blood Institute's Severe Asthma Research Program (SARP) has been at the forefront of phenotype discovery in severe asthma for the past decade. SARP, along with other international groups, has described clinical severe asthma phenotypes in both adults and children that can be evaluated in the clinical setting. Although these clinical phenotypes provide a good "starting point" for addressing disease heterogeneity in severe asthma in everyday practice, more efforts are needed to understand how these phenotypes relate to underlying disease mechanisms and pharmacological treatment responses. This review highlights the clinical asthma phenotypes identified to date, their associations with underlying endotypes and potential biomarkers, and remaining knowledge gaps that must be addressed before precision medicine can become a reality for patients with severe asthma.

Predictors of enhanced response with benralizumab for patients with severe asthma: pooled analysis of the SIROCCO and CALIMA studies

BACKGROUND

Benralizumab is an anti-eosinophilic, anti-interleukin-5 receptor α monoclonal antibody that has been shown to significantly reduce asthma exacerbations and improve lung function for patients with severe, uncontrolled asthma. We further explored the efficacy of benralizumab for patients with different baseline blood eosinophil thresholds and exacerbation histories.

METHODS

This study is a pooled analysis of the results from the randomised, double-blind, placebo-controlled SIROCCO (NCT01928771) and CALIMA (NCT01914757) phase 3 studies. In these studies, patients with severe, uncontrolled asthma were randomly assigned (1:1:1) to receive subcutaneous benralizumab 30 mg, either every 4 weeks or every 8 weeks (with first three doses given every 4 weeks), or placebo every 4 weeks. The primary endpoint was annual exacerbation rate (AER) ratio versus placebo, analysed by baseline eosinophil counts (≥0, ≥150, ≥300, or ≥450 cells per μL) and by number of exacerbations (two vs three or more) during the year before enrolment. The analyses were done in accordance with the intention-to-treat principle.

FINDINGS

Of 2295 patients, 756 received benralizumab every 4 weeks, 762 received benralizumab every 8 weeks, and 777 patients received placebo. AER among patients with baseline blood eosinophil counts of at least 0 cells per μL was 1·16 (95% CI 1·05-1·28) in patients who received placebo versus 0·75 (0·66-0·84) in patients who received benralizumab every 8 weeks (rate ratio 0·64, 0·55-0·75; p<0·0001). In patients who received benralizumab every 4 weeks who had eosinophil counts of 0 or more cells per μL, AER was 0·73 (0·65-0·82); rate ratio versus placebo was 0·63 (0·54-0·74; p<0·0001). The extent to which exacerbation rates were reduced increased with increasing blood eosinophil thresholds and with greater exacerbation history in patients in the 4-weekly and 8-weekly benralizumab groups. Greater improvements in AER were seen with benralizumab compared with placebo for patients with a combination of high blood eosinophil thresholds and a history of more frequent exacerbations.

INTERPRETATION

These results will help to guide clinicians when they are deciding whether to use benralizumab to treat patients with severe, uncontrolled, eosinophilic asthma.

FUNDING

AstraZeneca.

The association between blood eosinophil count and benralizumab efficacy for patients with severe, uncontrolled asthma: subanalyses of the Phase III SIROCCO and CALIMA studies

OBJECTIVE

Benralizumab, an anti-eosinophilic monoclonal antibody, in combination with high-dosage inhaled corticosteroids and long-acting β₂-agonists (ICS/LABA), significantly reduced asthma exacerbations, improved lung function, and reduced symptoms for patients with severe, uncontrolled asthma with blood eosinophil counts ≥300 cells/μL in the Phase III SIROCCO and CALIMA studies. To understand the efficacy and safety of benralizumab for patients with eosinophil-driven disease with blood eosinophil counts lower than 300 cells/μL, we evaluated the effect of applying an eosinophil cutoff of ≥150 cells/μL.

METHODS

Adult patients with uncontrolled asthma despite high-dosage ICS/LABA ± additional asthma controller(s) received subcutaneous benralizumab 30 mg every 8 weeks (Q8W; first three doses every 4 weeks) or placebo for 48 (SIROCCO) or 56 (CALIMA) weeks. Efficacy measures including annual exacerbation rate, prebronchodilator FEV₁, and total asthma symptom score were analyzed by baseline blood eosinophil counts ≥150 vs. <150 cells/μL.

RESULTS

Benralizumab reduced asthma exacerbation rates by 42% in SIROCCO (rate ratio = 0.58; 95% CI = 0.46-0.74; p < 0.001; n = 325) and 36% in CALIMA (rate ratio = 0.64; 95% CI = 0.50-0.81; p < 0.001; n = 300) vs. placebo (n = 306 for SIROCCO, n = 315 for CALIMA) for patients with blood eosinophil counts ≥150 cells/μL. Benralizumab increased prebronchodilator FEV₁ (both studies, p ≤ 0.002) and improved total asthma symptom score in SIROCCO (p = 0.009) at end of treatment vs. placebo for patients with blood eosinophil counts ≥150 cells/μL. The overall adverse events frequency was similar between treatment groups and eosinophil count cohorts.

CONCLUSION

These results support the efficacy and safety of benralizumab for patients with severe asthma and blood eosinophil counts ≥150 cells/μL.

Pharmacokinetic/pharmacodynamic drug evaluation of benralizumab for the treatment of asthma

INTRODUCTION

In many severe asthmatics, eosinophils cause inflammation and airways hyperresponsiveness, resulting in frequent exacerbations, impaired lung function, and reduced quality of life. Interleukin-5 (IL-5) is a key cytokine for eosinophil growth, differentiation, recruitment, activation, and survival. Anti-IL-5-based therapies (mepolizumab and reslizumab are humanized monoclonal antibodies (hmAbs) that recognize free IL-5, benralizumab is a hmAb directed at the α subunit of the IL-5R) target the IL-5-signaling in eosinophilic asthma. Areas covered: The pharmacodynamic/pharmacokinetic profile of benralizumab and how it provided indications that permitted optimization of the design and timelines of the pivotal trials are described. Expert opinion: Benralizumab has the advantage over other anti-IL-5 therapies to target the IL-5Rα itself. Afucosylation enhances its interaction with its binding site and facilitates its pharmacological activity. Other benefits of benralizumab are fast (within 24 h) depletion of peripheral blood eosinophils, potent suppressive activity of bone marrow eosinophils and eosinophil precursors, tissue eosinophil apoptosis regardless of the presence of eosinophil survival factors and even at low IL-5R densities. The fact that benralizumab is dosed subcutaneously and is equally effective when given every eight weeks instead than every four weeks provides patients with convenience of self-administration and make it appealing for patients who dislike injections.

Is it possible to claim or refute sputum eosinophils ≥ 3% in asthmatics with sufficient accuracy using biomarkers?

The concept of asthma inflammatory phenotypes has proved to be important in predicting response to inhaled corticosteroids. Induced sputum, which has been pivotal in the development of the concept of inflammatory phenotypes, is however not widely available. Several studies have proposed to use surrogate exhaled or blood biomarkers, like fractional exhaled nitric oxide (FENO), blood eosinophils and total serum immunoglobulin E (IgE). However, taken alone, each of these biomarkers has moderate accuracy to identify sputum eosinophilia. Here, we propose a new approach based on the likelihood ratio to study which thresholds of these biomarkers, taken alone or in combination, were able to rule in or rule out sputum eosinophils ≥3%. We showed in a large population of 869 asthmatics that combining FENO, blood eosinophils and total serum IgE could accurately predict sputum eosinophils ≥ or <3% in 58% of our population.