Asthma outcomes: biomarkers

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.

A Nasal Brush-based Classifier of Asthma Identified by Machine Learning Analysis of Nasal RNA Sequence Data

Asthma is a common, under-diagnosed disease affecting all ages. We sought to identify a nasal brush-based classifier of mild/moderate asthma. 190 subjects with mild/moderate asthma and controls underwent nasal brushing and RNA sequencing of nasal samples. A machine learning-based pipeline identified an asthma classifier consisting of 90 genes interpreted via an L2-regularized logistic regression classification model. This classifier performed with strong predictive value and sensitivity across eight test sets, including (1) a test set of independent asthmatic and control subjects profiled by RNA sequencing (positive and negative predictive values of 1.00 and 0.96, respectively; AUC of 0.994), (2) two independent case-control cohorts of asthma profiled by microarray, and (3) five cohorts with other respiratory conditions (allergic rhinitis, upper respiratory infection, cystic fibrosis, smoking), where the classifier had a low to zero misclassification rate. Following validation in large, prospective cohorts, this classifier could be developed into a nasal biomarker of asthma.

Asthma Endotyping and Biomarkers in Childhood Asthma

Childhood asthma represents a heterogeneous challenging disease, in particular in its severe forms. The identification of different asthma phenotypes has stimulated research in underlying molecular mechanisms, such as the endotypes, and paved the way to the search for related specific biomarkers, which may guide diagnosis, management, and predict response to treatment. A limited number of biomarkers are currently available in clinical practice in the pediatric population, mostly reflecting type 2-high airway inflammation. The identification of biomarkers of childhood asthma is an active area of research that holds a potential great clinical utility and may represent a step forward toward tailored management and therapy: the so-called Precision Medicine. The aim of the present review is to provide an updated overview of asthma endotyping, mostly focusing on novel noninvasive biomarkers in childhood asthma.

Indoor mould exposure, asthma and rhinitis: findings from systematic reviews and recent longitudinal studies

Starting from the Institute of Medicine (IOM) and World Health Organization (WHO) reports, this review provides an overview of the literature published from 2006 to 2017 on the associations between indoor mould exposure and asthma and rhinitis separately in children and adults with a focus on longitudinal epidemiological studies.A systematic search of peer-reviewed literature was performed, including systematic reviews and meta-analyses, longitudinal, incident case-control and panel studies. 61 publications were identified reporting visible mould or mould odour or quantitative assessment of culturable fungi or mould species.In children, visible mould and mould odour were associated with the development and exacerbations of asthma, providing sufficient evidence of a causal relationship. Results from population-based studies in adults were too few and divergent to conclude at more than a limited level of evidence. Exposure to mould in a work building was associated with the incidence and exacerbations of occupational asthma, and we concluded at a sufficient evidence for an association. Systematic reviews, meta-analyses and longitudinal studies on the relationships between mould exposure and allergic rhinitis provide sufficient evidence of an association.This review extended the conclusions of the IOM and WHO reports, and highlighted the need for further longitudinal studies on asthma in adults, and on rhinitis.

Longitudinal vitamin D deficiency is inversely related to mite sensitization in early childhood

BACKGROUND

There are few studies addressing the longitudinal analysis of vitamin D deficiency and its impact on the development of atopic diseases in early childhood.

METHODS

We investigated 155 children who regularly followed up at our clinic for 5 years as subjects enrolled in a birth cohort study. The pattern of vitamin D levels from birth to 5 years of age was clustered using K-means method in R software. Absolute eosinophil count (AEC), and total serum and specific immunoglobulin E antibodies against food (egg white, milk, and wheat) and inhalant allergens (Dermatophagoides pteronyssinus, Dermatophagoides farina, and Cladosporium herbarum) were measured at 1.5, 3, 4 and 5 years of age.

RESULTS

A total of 137 children with serum samples obtained over at least 3 time points during the follow-up period were recruited. Using K-means clustering, the dynamic changes in vitamin D levels were significantly stratified into 3 clusters (cluster A, ≥30 ng/mL, n = 61; cluster B, 20-29.9 ng/mL, n = 53; cluster C, <20 ng/mL, n = 23). Despite no statistical association with atopic diseases, a persistent vitamin D deficiency appeared to be associated with eosinophilia at age 3, and total serum and mite-specific immunoglobulin E (IgE) levels at age 4. Furthermore, an associated higher prevalence of mite sensitization at age 4 was significantly associated with the risk of allergic rhinitis and asthma.

CONCLUSIONS

Vitamin D deficiency is inversely associated with AEC and mite-specific IgE levels, which may potentially increase susceptibility to develop allergies including rhinitis and asthma in early childhood.

Associations between blood eosinophils and decline in lung function among adults with and without asthma

Eosinophilic inflammation and airway remodelling are characteristic features of asthma, but the association between them is unclear. We assessed associations between blood eosinophils and lung function decline in a population-based cohort of young adults.We used linear mixed models to analyse associations between blood eosinophils and spirometry at 21, 26, 32 and 38 years adjusting for sex, smoking, asthma and spirometry at age 18 years. We further analysed associations between mean eosinophil counts and changes in spirometry from ages 21 to 38 years.Higher eosinophils were associated with lower forced expiratory volume in 1 s (FEV₁)/forced vital capacity (FVC) ratios and lower FEV₁ % predicted values for both pre- and post-bronchodilator spirometry (all p-values ≤0.048). Although eosinophil counts were higher in participants with asthma, the associations between eosinophils and spirometry were similar among participants without asthma or wheeze. Participants with mean eosinophil counts >0.4×10⁹ cells·L^-1 between 21 and 38 years had greater declines in FEV₁/FVC ratios (difference 1.8%, 95% CI 0.7-2.9%; p=0.001) and FEV₁ values (difference 3.4% pred, 95% CI 1.5-5.4% pred); p=0.001) than those with lower counts.Blood eosinophils are associated with airflow obstruction and enhanced decline in lung function, independently of asthma and smoking. Eosinophilia is a risk factor for airflow obstruction even in those without symptoms.

Asthma across the lifespan: Time for a paradigm shift

We have a unique opportunity to significantly reduce the worldwide burden of asthma in children and affect respiratory outcomes in adults. However, this will require a paradigm shift that is directed at altering the natural history of asthma, reducing asthma exacerbations, and preventing long-term adverse outcomes of childhood asthma. Attention should continue to be directed toward minimizing risk, as well as impairment, with a goal to achieve optimal control. Based on several National Institutes of Health studies conducted over the last 10 years, we now have the tools necessary to accomplish this goal. The tools include assessment of lung function over time or defining trajectories of lung growth, the Composite Asthma Severity Index score, a panel of useful biomarkers, the Seasonal Asthma Exacerbation Prediction Index score, and rapidly advancing technology that includes adherence monitoring. Future guideline revisions should consider incorporating recommendations to follow spirometry over time and defining trajectories of lung growth to assess risk for reduced lung growth and early decline, asthma burden by using biomarkers to select and monitor therapy, assessment of social determinants of health, evaluation of risk for seasonal exacerbations, and consideration of electronic adherence monitoring for difficult-to-manage asthma. Guidelines should continue to include a core dedicated to the diagnosis and treatment of intermittent and mild and moderate persistent asthma and include additional sections dedicated to the management of severe asthma.

Tralokinumab for the treatment of severe, uncontrolled asthma: the ATMOSPHERE clinical development program

Tralokinumab, a fully human IgG₄ monoclonal antibody, specifically neutralizes IL-13. The ATMOSPHERE clinical development program comprised four randomized, placebo-controlled clinical trials and an open-label study that aimed to assess the efficacy and safety of tralokinumab for the treatment of severe, uncontrolled asthma. The two pivotal trials (STRATOS 1 and STRATOS 2; NCT02161757 and NCT02194699) evaluated the efficacy and safety of tralokinumab, with STRATOS 1 identifying a subgroup most likely to demonstrate enhanced response to treatment. Further trials have assessed the ability of tralokinumab to reduce oral corticosteroid use (TROPOS; NCT02281357) and determined its mechanistic effects (MESOS; NCT02449473). An open-label study in Japanese individuals (NCT02902809) assessed the long-term safety and tolerability of tralokinumab in this population.

Serum Periostin as a Biomarker for Comorbid Chronic Rhinosinusitis in Patients with Asthma

RATIONALE

Periostin is a matricellular protein that is involved in the pathophysiology of allergic rhinitis, chronic rhinosinusitis, and asthma. Associations of serum periostin with systemic and airway eosinophilic inflammation and comorbid chronic rhinosinusitis in patients with asthma have been demonstrated. Although serum periostin is positioned as a marker of helper T cell 2 immune responses, its implication regarding the presence of comorbid upper airway diseases in patients with asthma remains unclear.

OBJECTIVES

To investigate the utility of serum periostin as a diagnostic biomarker for upper airway disease in patients with asthma.

METHODS

We prospectively enrolled 65 patients with stable asthma, 20 without upper airway disease, 22 with rhinitis, and 23 with chronic rhinosinusitis (13 with nasal polyps, 10 without). Serum periostin, eotaxin, total IgE, fractional exhaled nitric oxide, and blood and sputum eosinophil levels were measured and compared between upper airway disease subtypes. We evaluated the utility of each biomarker in detecting upper airway disease, associations among the biomarkers, and severity of upper airway disease as measured by the Lund-Mackay score for sinus computed tomography.

RESULTS

Serum periostin levels were higher in patients with asthma who had chronic rhinosinusitis (109.6 ± 47.4 ng/ml) than in those without upper airway disease (83.2 ± 22.9 ng/ml) (P = 0.04). Serum periostin levels in patients with asthma who had chronic rhinosinusitis and nasal polyps were significantly higher (130.0 ± 46.6 ng/ml) than in those without nasal polyps (87.9 ± 37.7 ng/ml) (P  =  0.001). Serum periostin levels were not associated with the presence or the severity of rhinitis. In contrast, receiver operating characteristic curve analyses showed moderate diagnostic accuracy for detecting chronic rhinosinusitis (area under the curve, 0.71; P = 0.01) and high accuracy for chronic rhinosinusitis with nasal polyps (area under the curve, 0.86; P = 0.0002). When we compared patients with asthma who had comorbid chronic rhinosinusitis and nasal polyps with patients with asthma without these comorbidities, we found serum periostin to be the sole biomarker among those tested for detecting the presence of nasal polyps. Serum periostin was also the sole biomarker that significantly correlated with Lund-Mackay score in patients with chronic rhinosinusitis (r = 0.44; P = 0.04).

CONCLUSIONS

Serum periostin is useful for detecting chronic rhinosinusitis with nasal polyps and predicting radiological chronic rhinosinusitis severity in patients with asthma. Clinical trial registered with the UMIN Clinical Trials Registry (UMIN000017533).

The distribution of blood eosinophil levels in a Japanese COPD clinical trial database and in the rest of the world

Background

Blood eosinophil measurements may help to guide physicians on the use of inhaled corticosteroids (ICS) for patients with chronic obstructive pulmonary disease (COPD). Emerging data suggest that COPD patients with higher blood eosinophil counts may be at higher risk of exacerbations and more likely to benefit from combined ICS/long-acting beta₂-agonist (LABA) treatment than therapy with a LABA alone. This analysis describes the distribution of blood eosinophil count at baseline in Japanese COPD patients in comparison with non-Japanese COPD patients.

Methods

A post hoc analysis of eosinophil distribution by percentage and absolute cell count was performed across 12 Phase II–IV COPD clinical studies (seven Japanese studies [N=848 available absolute eosinophil counts] and five global studies [N=5,397 available eosinophil counts] that included 246 Japanese patients resident in Japan with available counts). Blood eosinophil distributions were assessed at baseline, before blinded treatment assignment.

Findings

Among Japanese patients, the median (interquartile range) absolute eosinophil count was 170 cells/mm³ (100–280 cells/mm³). Overall, 612/1,094 Japanese patients (56%) had an absolute eosinophil count ≥150 cells/mm³ and 902/1,304 Japanese patients (69%) had a percentage eosinophil ≥2%. Among non-Japanese patients, these values were 160 (100–250) cells/mm³, 2,842/5,151 patients (55%), and 2,937/5,155 patients (57%), respectively. The eosinophil distribution among Japanese patients was similar to that among non-Japanese patients. Within multi-country studies with similar inclusion criteria, the eosinophil count was numerically lower in Japanese compared with non-Japanese patients (median 120 vs 160 cells/mm³).

Interpretation

The eosinophil distribution in Japanese patients seems comparable to that of non-Japanese patients; although within multi-country studies, there was a slightly lower median eosinophil count for Japanese patients compared with non-Japanese patients. These findings suggest that blood eosinophil data from global studies are of relevance in Japan.

Altered Serum Metabolite Profiling and Relevant Pathway Analysis in Rats Stimulated by Honeybee Venom: New Insight into Allergy to Honeybee Venom

To improve our understanding of the disturbed metabolic pathways and cellular responses triggered by honeybee venom stimulation, we compared the changes in serum metabolites in rats, either stimulated or not by honeybee venom, by performing ¹H nuclear magnetic resonance (NMR) spectrometry-based metabonomics to identify potential biomarkers. In this study, 65 metabolites were structurally confirmed and quantified and the following results were obtained. First, by pattern recognition analysis, 14 metabolites were selected as potential biomarkers 3 h after venom stimulation. Second, metabolic pathway analysis showed that methane metabolism, glyoxylate and dicarboxylate metabolism, tricarboxylic acid cycle, glycine, serine, and threonine metabolism, arginine and proline metabolism were affected. Finally, the time-dependent metabolic modifications indicated that rats could recover without medical treatment 24 h after venom stimulation. In summary, this new insight into the changes in serum metabolites in rats after honeybee venom stimulation has enhanced our understanding of the response of an organism to honeybee venom.

Severe bronchial asthma in children: a review of novel biomarkers used as predictors of the disease

Severe asthma or therapy-resistant asthma in children is a heterogeneous disease that affects all age-groups. Given its heterogeneity, precision in diagnosis and treatment has become imperative, in order to achieve better outcomes. If one is thus able to identify specific patient phenotypes and endotypes using the appropriate biomarkers, it will assist in providing the patient with more personalized and appropriate treatment. However, there appears to be a huge diagnostic gap in severe asthma, as there is no single test yet that accurately determines disease phenotype. In this paper, we review the published literature on some of these biomarkers and their possible role in bridging this diagnostic gap. We also highlight the cellular and molecular mechanisms involved in severe asthma, in order to show the basis for the novel biomarkers. Some markers useful for monitoring therapy and assessing airway remodeling in the disease are also discussed. A review of the literature was conducted with PubMed to gather baseline data on the subject. The literature search extended to articles published within the last 40 years. Although biomarkers specific to different severe asthma phenotypes have been identified, progress in their utility remains slow, because of several disease mechanisms, the variation of biomarkers at different levels of inflammation, changes in relying on one test over time (eg, from sputum eosinophilia to blood eosinophilia), and the degree of invasive tests required to collect biomarkers, which limits their applicability in clinical settings. In conclusion, several biomarkers remain useful in recognizing various asthma phenotypes. However, due to disease heterogeneity, identification and utilization of ideal and defined biomarkers in severe asthma are still inconclusive. The development of novel serum/sputum-based biomarker panels with enhanced sensitivity and specificity may lead to prompt diagnosis of the disease in the future.

Clinical and inflammatory phenotyping by breathomics in chronic airway diseases irrespective of the diagnostic label

Asthma and chronic obstructive pulmonary disease (COPD) are complex and overlapping diseases that include inflammatory phenotypes. Novel anti-eosinophilic/anti-neutrophilic strategies demand rapid inflammatory phenotyping, which might be accessible from exhaled breath.Our objective was to capture clinical/inflammatory phenotypes in patients with chronic airway disease using an electronic nose (eNose) in a training and validation set.This was a multicentre cross-sectional study in which exhaled breath from asthma and COPD patients (n=435; training n=321 and validation n=114) was analysed using eNose technology. Data analysis involved signal processing and statistics based on principal component analysis followed by unsupervised cluster analysis and supervised linear regression.Clustering based on eNose resulted in five significant combined asthma and COPD clusters that differed regarding ethnicity (p=0.01), systemic eosinophilia (p=0.02) and neutrophilia (p=0.03), body mass index (p=0.04), exhaled nitric oxide fraction (p<0.01), atopy (p<0.01) and exacerbation rate (p<0.01). Significant regression models were found for the prediction of eosinophilic (R²=0.581) and neutrophilic (R²=0.409) blood counts based on eNose. Similar clusters and regression results were obtained in the validation set.Phenotyping a combined sample of asthma and COPD patients using eNose provides validated clusters that are not determined by diagnosis, but rather by clinical/inflammatory characteristics. eNose identified systemic neutrophilia and/or eosinophilia in a dose-dependent manner.

The current and future role of biomarkers in type 2 cytokine-mediated asthma management

Assessment and management of asthma is complicated by the heterogeneous pathophysiological mechanisms that underlie its clinical presentation, which are not necessarily reflected in standardized management paradigms and which necessitate an individualized approach to treatment. This is particularly important with the emerging availability of a variety of targeted forms of therapy that may only be appropriate for use in particular patient subgroups. The identification of biomarkers can potentially aid diagnosis and inform prognosis, help guide treatment decisions and allow clinicians to predict and monitor response to treatment. Biomarkers for asthma have been identified from a variety of sources, including airway, exhaled breath and blood. Biomarkers from exhaled breath include fractional exhaled nitric oxide, measurement of which can help identify patients most likely to benefit from inhaled corticosteroids and targeted anti-immunoglobulin E therapy. Biomarkers measured in blood are relatively non-invasive and technically more straightforward than those measured from exhaled breath or directly from the airway. The most well established of these are the blood eosinophil count and serum periostin, both of which have demonstrated utility in identifying patients most likely to benefit from targeted anti-interleukin and anti-immunoglobulin E therapies, and in monitoring subsequent treatment response. For example, serum periostin appears to be a biomarker for responsiveness to inhaled corticosteroid therapy and may help identify patients as suitable candidates for anti-IL-13 treatment. The use of biomarkers can therefore potentially help avoid unnecessary morbidity from high-dose corticosteroid therapy and allow the most appropriate and cost-effective use of targeted therapies. Ongoing clinical trials are helping to further elucidate the role of established biomarkers in routine clinical practice, and a range of other circulating novel potential biomarkers are currently being investigated in the research setting.

Methodology for Sputum Induction and Laboratory Processing

The technique of sputum induction and processing is a recognized non-invasive method allowing the collection and analysis of cells from the airways, which is interesting in various respiratory diseases like asthma, chronic obstructive pulmonary disease (COPD), chronic cough, or idiopathic pulmonary fibrosis. This technique is well tolerated, safe and non-invasive, but is currently limited to research services and specialized centers in clinical practice because it is technically demanding, time-consuming, and requires trained staff. The success rate of sputum induction and analysis is about 80%. Here, we describe the induction and laboratory processing of sputum samples. Sputum is induced by inhalation of hypertonic or isotonic saline with salbutamol. For the processing, we use the whole sputum technique. Dithiothreitol (DTT) is used to allow mucolysis of sputum samples. The primary aim of sputum processing is to obtain a differential cell count to study the cell types present in the airway lumen. Additional analyses may also be performed on sputum supernatant and sputum cells, which may allow further investigation into inflammatory processes and immune mechanisms. Examples include studying mediators in sputum supernatant and performing a large spectrum of analysis on sputum cells such as flow cytometry, genomics, or proteomics. Finally, representative results of sputum analysis in healthy controls, asthmatics, and COPD patients are presented.

Asthma biomarkers in the age of biologics

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

How should treatment approaches differ depending on the severity of asthma?

INTRODUCTION

Asthma is nowadays regarded as a syndrome of various overlapping phenotypes with defined clinical characteristics, different underlying inflammatory mechanisms, identifiable genetic background, environmental risk factors and possible biomarkers. There are no doubts that due to the diversity of asthma, a 'one size fits all' management of the disease is no longer valid. Areas covered: Nowadays asthma management is based on the control of the disease, and the goals of asthma treatment are defined as good symptom control, decreased future risk of exacerbations, fixed airflow limitation, and side-effects of treatment. Alternative strategies for adjusting asthma treatment such as sputum or exhaled nitric oxide guided protocols have been evaluated and despite some effectiveness, are regarded as impractical in every-day clinical conditions. Further studies in the field of asthma phenotypes/endotypes and biomarkers are warranted with the main goal to define which of those possible subgroups will be useful in clinical practice in regards to the potential allocation of successful treatment. Expert commentary: Despite the availability of guidelines on the diagnosis and management of asthma, it seems that the disease is still not optimally controlled. Addressing unmet needs in every day care, improving education, adherence/compliance and inhalation technique may significantly improve asthma control across all severities of the disease.

Interleukin-13 in Asthma and Other Eosinophilic Disorders

Asthma is characterized by episodic, reversible airflow obstruction associated with variable levels of inflammation. Over the past several decades, there has been an increasing appreciation that the clinical presentation of asthma comprises a diverse set of underlying pathologies. Rather than being viewed as a single disease entity, asthma is now thought of as a clinical syndrome with the involvement of multiple pathological mechanisms. While it is appreciated that eosinophilia is present in only a subset of patients, it remains a key feature of asthma and other eosinophilic disorders such as atopic dermatitis, eosinophilic esophagitis, and chronic rhinosinusitis with nasal polyps. Eosinophils are bone marrow-derived leukocytes present in low numbers in health; however, during disease the type 2 cytokines [interleukins (IL)-4, -5, and -13] can induce rapid eosinophilopoiesis, prolonged eosinophil survival, and trafficking to the site of injury. In diseases such as allergic asthma there is an aberrant inflammatory response leading to eosinophilia, tissue damage, and airway pathology. IL-13 is a pleiotropic type 2 cytokine that has been shown to be integral in the pathogenesis of asthma and other eosinophilic disorders. IL-13 levels are elevated in animal models of eosinophilic inflammation and in the blood and tissue of patients diagnosed with eosinophilic disorders. IL-13 signaling elicits many pathogenic mechanisms including the promotion of eosinophil survival, activation, and trafficking. Data from preclinical models and clinical trials of IL-13 inhibitors in patients have revealed mechanistic insights into the role of this cytokine in driving eosinophilia. Promising results from clinical trials further support a key mechanistic role of IL-13 in asthma and other eosinophilic disorders. Here, we provide a perspective on the role of IL-13 in asthma and other eosinophilic disorders and describe ongoing clinical trials targeting this pathway in patients with significant unmet medical needs.

Emerging interleukin receptor antagonists for the treatment of asthma

INTRODUCTION

Asthma is a heterogeneous disease, usually characterized by chronic airway inflammation. Most patients with asthma can be well-controlled with inhaled corticosteroids and, if necessary, the addition of a long-acting beta agonist. Despite these therapies, 5% to 10% of patients with asthma have severe, uncontrolled asthma. Selecting patients based on peripheral eosinophil counts and a history of exacerbations has led to significant decreases in exacerbations and an improvement in asthma control with medications that target IL-4, IL-5 and IL-13/. Areas covered: This review will cover the definition of severe asthma, existing treatment options, biomarkers, and the emerging role of interleukin antagonists in the treatment of severe asthma. Expert opinion: IL antagonists are novel drugs targeting important inflammatory cytokines in asthma. Anti-IL-5 drugs provide the most promise as they have obtained regulatory approval and are available for use. Anti-IL-4 drug results are also promising. There is, however, uncertainty regarding the success of anti-IL-13 drugs development at this point. An ongoing focus of research is to significantly increase our understanding of the biology of asthma, and in particular severe asthma, making more and better targeted therapies. There may also be potential in the future to use these new drugs earlier in the development of asthma, as disease-modifying interventions that might be associated with remission or even cure.

Caesarean Section is associated with reduced perinatal cytokine response, increased risk of bacterial colonization in the airway, and infantile wheezing

The relationship between cesarean section (CS) and allergic disorders such as asthma and wheezing has been inconsistent, and the mechanisms for their connection remained largely unknown. We aimed to investigate whether CS is associated with infantile wheeze and to explore the connection between CS and several risk factors known to correlate with allergy development. Mononuclear cells were isolated from cord blood and assessed for cytokine responses by ELISA. Bacteria from nasopharyngeal specimens were identified with traditional culture methods. Infant lung function tests were performed at 6 and 12 months of age. IgE levels and clinical outcomes were assessed at 12 months. The result showed that children delivered by CS were associated with increased risk of wheezing (aHR 1.63; 95% CI: 1.01–2.62) and decreased compliance of the respiratory system at 12 months (p = 0.045). In addition, CS was associated with reduced TLR1–2- triggered TNF-α and IL-6 responses at birth. By12 months of age, children delivered by CS had significantly less airway bacterial clearance. Our findings suggested that CS was associated with decreased pro-inflammatory cytokine response to TLR1–2 stimulation, followed by higher abundance of bacterial colonization in the airway during late infancy, thus increasing the risk of infantile wheezing.

Potential Biomarkers for NSAID-Exacerbated Respiratory Disease

Asthma is a common chronic disease with several variant phenotypes and endotypes. NSAID-exacerbated respiratory disease (NERD) is one such endotype characterized by asthma, chronic rhinosinusitis (CRS) with nasal polyps, and hypersensitivity to aspirin/cyclooxygenase-1 inhibitors. NERD is more associated with severe asthma than other asthma phenotypes. Regarding diagnosis, aspirin challenge tests via the oral or bronchial route are a standard diagnostic method; reliable in vitro diagnostic tests are not available. Recent studies have reported various biomarkers of phenotype, diagnosis, and prognosis. In this review, we summarized the known potential biomarkers of NERD that are distinct from those of aspirin-tolerant asthma. We also provided an overview of the different NERD subgroups.

More than a decade follow-up in patients with severe or difficult-to-treat asthma: The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR) II

BACKGROUND

The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR I) study demonstrated high morbidity in patients with severe or difficult-to-treat asthma despite standard-of-care treatment.

OBJECTIVE

We sought to determine the long-term natural history of disease and outcomes in patients in TENOR I after more than a decade.

METHODS

TENOR I was a multicenter observational study (2001-2004) of 4756 patients with severe or difficult-to-treat asthma. TENOR II was a follow-up study of TENOR I patients using a single cross-sectional visit in 2013/2014. Overall, the sites participating in TENOR II originally enrolled 1230 patients in TENOR I. Clinical and patient-reported outcomes were assessed, including very poorly controlled asthma based on National Heart, Lung, and Blood Institute guidelines.

RESULTS

A total of 341 (27.7%) patients were enrolled in TENOR II and were representative of the TENOR I cohort. The most frequent comorbidities were rhinitis (84.0%), sinusitis (47.8%), and gastroesophageal reflux disease (46.3%). Mean percent predicted prebronchodilator and postbronchodilator FEV₁ were 72.7% (SD, 21.4%) and 78.2% (SD, 20.7%), respectively. A total of 231 (72.9%) of 317 patients had positive test responses to 1 or more allergen-specific IgEs. The mean blood eosinophil count was 200/μL (SD, 144/μL). Eighty-eight (25.8%) patients experienced an asthma exacerbation in the prior 3 months requiring hospital attention, oral corticosteroids, or both. More than half (197/339 [58.1%]) had very poorly controlled asthma. Medication use suggested undertreatment.

CONCLUSION

TENOR II provides longitudinal data to characterize disease progression, heterogeneity, and severity in patients with severe or difficult-to-treat asthma. Findings show continued morbidity, including a high degree of comorbid conditions, allergic sensitization, exacerbations, and very poorly controlled asthma, including reduced lung function.

Measuring safety of inhaled corticosteroids in asthma

BACKGROUND

Despite evidence demonstrating generally excellent therapeutic ratios for inhaled corticosteroids (ICSs) in asthma treatment, many clinicians and patients have ongoing concerns regarding their safety. To frame discussions of ICS safety, it is important to understand how safety is measured.

OBJECTIVE

To discuss how ICS safety is and should be measured.

METHODS

Discussion is augmented by relevant articles from the literature.

RESULTS

The therapeutic value of corticosteroids depends on the activation and repression of thousands of genes. However, it is not fully known which genes cause the desirable, therapeutic effects and which cause the adverse effects. The drug development process attempts to elucidate the clinically significant therapeutic effects and adverse effects of a candidate molecule and then compare them to those of currently available corticosteroids. Approaches to monitoring safety include clinical trials, retrospective comparison to historical efficacy and safety data, surrogate markers, animal models, and in vitro assays. Both preclinical and clinical data are used to compare safety among corticosteroids; however, no specific pathway or model that can robustly predict therapeutic ratios has been identified. Furthermore, variation in adverse effects is influenced by isoforms of the glucocorticoid receptor, differences in corticosteroid characteristics, differences among patients, and environmental variation.

CONCLUSION

Although some preclinical and patient-based metrics have predictive value, there is a clear need for improved biomarkers of corticosteroid adverse effects. Integrated analysis of preclinical and clinical data, including long-term safety data, could be used to address this important unmet need.

Proteomics for Allergy: from Proteins to the Patients

Proteomics encompasses a variety of approaches unraveling both the structural features, post-translational modifications, and abundance of proteins. As of today, proteomic studies have shed light on the primary structure of about 850 allergens, enabling the design of microarrays for improved molecular diagnosis. Proteomic methods including mass spectrometry allow as well to investigate protein-protein interactions, thus yielding precise information on critical epitopes on the surface of allergens. Mass spectrometry is now being applied to the unambiguous identification, characterization, and comprehensive quantification of allergens in a variety of matrices, as diverse as food samples and allergen immunotherapy drug products. As such, it represents a method of choice for quality testing of allergen immunotherapy products.

Lung Pathologies in a Chronic Inflammation Mouse Model Are Independent of Eosinophil Degranulation

RATIONALE

The release of eosinophil granule proteins in the lungs of patients with asthma has been dogmatically linked with lung remodeling and airway hyperresponsiveness. However, the demonstrated inability of established mouse models to display the eosinophil degranulation occurring in human subjects has prevented a definitive in vivo test of this hypothesis.

OBJECTIVES

To demonstrate in vivo causative links between induced pulmonary histopathologies/lung dysfunction and eosinophil degranulation.

METHODS

A transgenic mouse model of chronic T-helper cell type 2-driven inflammation overexpressing IL-5 from T cells and human eotaxin 2 in the lung (I5/hE2) was used to test the hypothesis that chronic histopathologies and the development of airway hyperresponsiveness occur as a consequence of extensive eosinophil degranulation in the lung parenchyma.

MEASUREMENT AND MAIN RESULTS

Studies targeting specific inflammatory pathways in I5/hE2 mice surprisingly showed that eosinophil-dependent immunoregulative events and not the release of individual secondary granule proteins are the central contributors to T-helper cell type 2-induced pulmonary remodeling and lung dysfunction. Specifically, our studies highlighted a significant role for eosinophil-dependent IL-13 expression. In contrast, extensive degranulation leading to the release of major basic protein-1 or eosinophil peroxidase was not causatively linked to many of the induced pulmonary histopathologies. However, these studies did define a previously unappreciated link between the release of eosinophil peroxidase (but not major basic protein-1) and observed levels of induced airway mucin.

CONCLUSIONS

These data suggest that improvements observed in patients with asthma responding to therapeutic strategies ablating eosinophils may occur as a consequence of targeting immunoregulatory mechanisms and not by simply eliminating the destructive activities of these purportedly end-stage effector cells.

Using imaging as a biomarker for asthma

There have been significant advancements in the various imaging techniques being used for the evaluation of asthmatic patients, both from a clinical and research perspective. Imaging characteristics can be used to identify specific asthmatic phenotypes and provide a more detailed understanding of endotypes contributing to the pathophysiology of the disease. Computed tomography, magnetic resonance imaging, and positron emission tomography can be used to assess pulmonary structure and function. It has been shown that specific airway and lung density measurements using computed tomography correlate with clinical parameters, including severity of disease and pathology, but also provide unique phenotypes. Hyperpolarized ¹²⁹Xe and ³He are gases used as contrast media for magnetic resonance imaging that provide measurement of distal lung ventilation reflecting small-airway disease. Positron emission tomography can be useful to identify and target lung inflammation in asthmatic patients. Furthermore, imaging techniques can serve as a potential biomarker and be used to assess response to therapies, including newer biological treatments and bronchial thermoplasty.

Advances in asthma in 2016: Designing individualized approaches to management

In this year's Advances in Asthma review, we discuss viral infections in asthmatic patients and potential therapeutic agents, the microbiome, novel genetic associations with asthma, air quality and climate effects on asthma, exposures during development and long-term sequelae of childhood asthma, patient-centered outcomes research, and precision medicine. In addition, we discuss application of biomarkers to precision medicine and new information on asthma medications. New evidence indicates that rhinovirus-triggered asthma exacerbations become more severe as the degree of sensitization to dust mite and mouse increase. The 2 biggest drivers of asthma severity are an allergy pathway starting with allergic sensitization and an environmental tobacco smoke pathway. In addition, allergic sensitization and blood eosinophils can be used to select medications for management of early asthma in young children. These current findings, among others covered in this review, represent significant steps toward addressing rapidly advancing areas of knowledge that have implications for asthma management.

Medicinal benefits of Nigella sativa in bronchial asthma: A literature review

Nigella sativa L. (NS) seeds, known as black seed, is a spice and a traditional herbal medicine used in various diseases including bronchial asthma. This review aimed to assess the studies supporting the medicinal use of NS in asthma and to highlight future research priorities. Various medical databases were searched for the effects of NS and its active secondary metabolites in asthma inflammation and outcomes. There were fourteen preclinical studies describing multiple effects of NS in animal or cellular models of asthma including bronchodilation, anti-histaminic, anti-inflammatory, anti-leukotrienes and immunomodulatory effects. Furthermore, seven clinical studies showed improvements in different asthma outcomes including symptoms, pulmonary function and laboratory parameters. However, often these studies are small and used ill-defined preparations. In conclusion, NS could be therapeutically beneficial in alleviating airway inflammation and the control of asthma symptoms, but the evidence remains scanty and is often based on poorly characterised preparations. Accordingly, well-designed large clinical studies using chemically well characterised NS preparation are required.

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.

Race is associated with differences in airway inflammation in patients with asthma

BACKGROUND

African American subjects have a greater burden from asthma compared with white subjects. Whether the pattern of airway inflammation differs between African American and white subjects is unclear.

OBJECTIVE

We sought to compare sputum airway inflammatory phenotypes of African American and white subjects treated or not with inhaled corticosteroids (ICSs; ICS+ and ICS-, respectively).

METHODS

We performed a secondary analysis of self-identified African American and white subjects with asthma enrolled in clinical trials conducted by the National Heart, Lung, and Blood Institute-sponsored Asthma Clinical Research Network and AsthmaNet. Demographics, clinical characteristics, and sputum cytology after sputum induction were examined. We used a sputum eosinophil 2% cut point to define subjects with either an eosinophilic (≥2%) or noneosinophilic (<2%) inflammatory phenotype.

RESULTS

Among 1018 participants, African American subjects (n = 264) had a lower FEV1 percent predicted (80% vs 85%, P < .01), greater total IgE levels (197 vs 120 IU/mL, P < .01), and a greater proportion with uncontrolled asthma (43% vs 28%, P < .01) compared with white subjects (n = 754). There were 922 subjects in the ICS+ group (248 African American and 674 white subjects) and 298 subjects in the ICS- group (49 African American and 249 white subjects). Eosinophilic airway inflammation was not significantly different between African American and white subjects in either group (percentage with eosinophilic phenotype: ICS+ group: 19% vs 16%, P = .28; ICS- group: 39% vs 35%, P = .65; respectively). However, when adjusted for confounding factors, African American subjects were more likely to exhibit eosinophilic airway inflammation than white subjects in the ICS+ group (odds ratio, 1.58; 95% CI, 1.01-2.48; P = .046) but not in the ICS- group (P = .984).

CONCLUSION

African American subjects exhibit greater eosinophilic airway inflammation, which might explain the greater asthma burden in this population.

High density lipoproteins and type 2 inflammatory biomarkers are negatively correlated in atopic asthmatics

Blood eosinophil counts and serum periostin levels are biomarkers of type 2 inflammation. Although serum levels of HDL and apoA-I have been associated with less severe airflow obstruction in asthma, it is not known whether serum lipids or lipoprotein particles are correlated with type 2 inflammation in asthmatics. Here, we assessed whether serum lipids and lipoproteins correlated with blood eosinophil counts or serum periostin levels in 165 atopic asthmatics and 163 nonasthmatic subjects with and without atopy. Serum lipids and lipoproteins were quantified using standard laboratory assays and NMR spectroscopy. Absolute blood eosinophils were quantified by complete blood counts. Periostin levels were measured using the Elecsys® periostin assay. In atopic asthmatics, blood eosinophils negatively correlated with serum HDL cholesterol and total HDL particles measured by NMR spectroscopy (HDL_NMR). Serum periostin levels negatively correlated with total HDL_NMR In contrast, blood eosinophil counts positively correlated with serum triglyceride levels. This study demonstrates for the first time that HDL particles were negatively correlated, whereas serum triglycerides were positively correlated, with blood eosinophils in atopic asthmatics. This supports the concept that serum levels of HDL and triglycerides may be linked to systemic type 2 inflammation in atopic asthma.

Biomarkers in asthmatic patients: Has their time come to direct treatment?

Asthma is a heterogeneous disease with multiple phenotypes that have variable risk factors and responses to therapeutics. Mild-to-moderate asthma often responds to traditional medications, whereas severe disease can be refractory to inhaled corticosteroids, long-acting β-agonists, and leukotriene receptor antagonists. There is robust research into the variable phenotypes of asthma. Biomarkers help define the specific pathophysiology of different asthma phenotypes and identify potential therapeutic targets. The following review will discuss the current use of biomarkers for the diagnosis of asthma, triaging the severity of a patient's disease, and the potential efficacy of treatments. This information can be used to define certain patient populations that are more likely to respond to inhaled corticosteroids or biologics. As knowledge of patient phenotypes and endotypes and biological agents to target specific classes of asthma emerge, the ability to provide personalized care to asthmatic patients will follow.

Mass spectrometry as a tool for biomarkers searching in gynecological oncology

Tumors of the female reproductive tract are an important target for the development of diagnostic, prognostic and therapeutic strategies. Recent research has turned to proteomics based on mass spectrometry techniques, to achieve more effective diagnostic results. Mass spectrometry (MS) enables identification and quantification of multiple molecules simultaneously in a single experiment according to mass to charge ratio (m/z). Several proteomic strategies may be applied to establish the function of a particular protein/peptide or to identify a novel disease and specific biomarkers related to it. Therefore, MS could facilitate treatment in patients with tumors by helping researchers discover new biomarkers and narrowly targeted drugs. This review presents a comprehensive discussion of mass spectrometry as a tool for biomarkers searching that may lead to the discovery of easily available diagnostic tests in gynecological oncology with emphasis on clinical proteomics over the past decade. The article provides an insight into different MS based proteomic approaches.

Stability of Blood Eosinophil Count in Patients with COPD in the UK Clinical Practice Research Datalink

Blood eosinophil counts may be predictive of corticosteroid response in chronic obstructive pulmonary disease (COPD) patients. However, little is known about measurement stability, which is important for understanding the utility of blood eosinophil counts as a potential biomarker. We evaluated the stability of blood eosinophil counts over 1 year in a population-based cohort of patients with COPD in primary care. Patients were aged ≥ 40 years with forced expiratory volume in 1 second/forced vital capacity < 0.7 and ≥ 1 blood eosinophil measurement taken during a period of stable disease within 6 months of a COPD diagnosis code recorded between January 1, 2010 and December 31, 2012. Generalized linear mixed models were fitted to log-transformed data to estimate the between-(s²_between) and within-patient (s²_within) variance in eosinophil count; an intra-class correlation coefficient R_i was calculated (s²_between/[s²_between + s²_within]). A sensitivity analysis was performed from which patients who were prescribed systemic corticosteroids or antibiotics at any time during follow-up were excluded. All models were adjusted for age, gender, smoking status, and asthma history. Overall, 27,557 patients were included in the full cohort (51.5% male, mean age [standard deviation] 71.1 [10.6] years) and 54% of patients had ≥ 2 eosinophil measurements (median 2 [interquartile range 1]) during follow-up. For the full cohort, R_i = 0.64, and in the sensitivity analysis subgroup, R_i = 0.70, mainly due to a decrease in s²_within. For patients with COPD in primary care, eosinophil measurements demonstrated reasonable repeatability over 1 year, which increased after exclusion of patients who were prescribed systemic corticosteroids or antibiotics.

Free 25(OH)D concentrations are associated with atopy and lung function in children with asthma

BACKGROUND

Evidence suggests free mono-hydroxyvitamin D (25[OH]D) concentrations are more strongly linked to certain outcomes than total concentrations; however, no studies have examined the relation between free 25(OH)D and respiratory or allergic disease.

OBJECTIVE

To examine associations between total and free 25(OH)D concentrations and asthma outcomes.

METHODS

We quantified total and free 25(OH)D concentrations in 137 Peruvian children with asthma and 152 children without asthma and examined associations with asthma outcomes.

RESULTS

Mean age ± SD was 13 ± 2.5 years, and 50.2% were boys. Mean total and measured free 25(OH)D concentrations were 29 ± 9.5 ng/mL and 5.0 ± 1.3 pg/mL, respectively. Lower free but not total 25(OH)D concentrations were significantly associated with atopy in all children (total, odds ratio [OR] 1.3 per 10-ng/mL decrease, 95% confidence interval [CI] 0.95-1.7, P = .12; vs free, OR 1.3 per 1-pg/mL decrease, 95% CI 1.0-1.6, P = .02) and children with asthma (total, OR 1.1 per 10-ng/mL decrease, 95% CI 0.75-1.7, P = .57; vs free, OR 1.6 per 1-pg/mL decrease, 95% CI 1.0-2.5, P = .04). Free but not total 25(OH)D levels were significantly associated with pre-bronchodilator forced expiratory volume in 1 second (total, 0.11 L, -0.12 to 0.34, P = .34; vs free, 0.20 L, 0.021-0.39, P = .03) and forced vital capacity (total, 0.13 L, -0.12 to 0.37, P = .31; vs free, 0.22 L, 0.026-0.42, P = .03) Z-scores in children with asthma.

CONCLUSION

Atopy, forced expiratory volume in 1 second, and forced vital capacity were more strongly linked to free than to total 25(OH)D concentrations, suggesting the free form might be more relevant in modulating allergic disease risk and pulmonary function in children with asthma.

Progression to Uncontrolled Severe Asthma: A Novel Risk Equation

BACKGROUND

Recently published asthma guidelines by the European Respiratory Society and the American Thoracic Society (ERS-ATS) define severe disease based on medication use and control level. These guidelines also emphasize that asthma severity involves certain biomarker phenotypes, one of them being eosinophilic phenotype. The quantification of the influence of eosinophil level toward predicting disease severity can help decision makers manage therapy better earlier.

OBJECTIVE

To develop a risk-scoring algorithm to identify patients at greater risk of developing uncontrolled severe asthma as defined by ERS-ATS guidelines.

METHODS

Data on asthma patients were extracted from the EMRClaims + database from January 2004 to July 2011. Patients with continuous enrollment 12 months before and after the date of the first encounter with a diagnosis of asthma (index date) with at least 1 blood eosinophil test result in the 12 months after the index date, but before the development of uncontrolled severe asthma or the study end date, were included. Uncontrolled severe asthma was defined as the first date on which all criteria of the ERS-ATS definition were first satisfied in the 12 months after the index date. Age (≥ 50 years vs. < 50 years), race, and sex were measured at index, and the Charlson Comorbidity Index (CCI) score (> 0 vs. 0) was measured in the pre-index period. Elevated eosinophil level was defined as a test result with ≥ 400 cells/µL. The study cohort was randomly split 50-50 into derivation and validation samples. Cox proportional hazards regression was used to develop the risk score for uncontrolled severe asthma using the derivation cohort with independent variables of eosinophil level, age, sex, race, and CCI. A bootstrapping procedure was used to generate 1,000 samples from the derivation cohort. Variables significant in ≥ 50% of the samples were retained in the final regression model. A risk score was then calculated based on the coefficient estimates of the final model. C-statistic was used to test the model's discrimination power.

RESULTS

The study included 2,405 patients, 147 (6%) of whom developed uncontrolled severe asthma. Higher eosinophil level and CCI score > 0 were significantly and independently associated with an increased risk of uncontrolled severe asthma in the derivation cohort (HR = 1.90, 95% CI = 1.17-3.08 and HR = 2.00, 95% CI = 1.28-3.13, respectively); findings were similar in the validation cohort. Total risk score was categorized as 0, 2, and 4. All models showed good C-statistics (0.79-0.80), indicating favorable model discrimination. There was a significantly greater number of patients with uncontrolled severe asthma in the risk score segments of 2 and 4 compared with 0 (each P < 0.0001).

CONCLUSIONS

A risk stratification tool using peripheral eosinophil counts and CCI can be used to predict the development of uncontrolled severe asthma.

DISCLOSURES

This study was funded by Teva Pharmaceuticals. eMAX Health Systems was a consultant to Teva Pharmaceuticals for this study and received payment from Teva Pharmaceuticals for work on this study. Casciano and Dotiwala are employed by eMAX Health Systems. Krishnan, Li, and Martin received payment from eMAX Health Systems for work on this study. Small was employed by Teva Pharmaceuticals at the time of this study. Study concept and design were contributed primarily by Casciano, Krishnan, Small, and Martin, along with Li and Dotiwala. Dotiwala, Casciano, Small, and Li collected the data, along with Martin and Li and Krishnan. Data interpretation was provided by Martin, Casciano, and Li, with assistance from the other authors. The manuscript was written by Li, Casciano, Dotiwala, and Small, with assistance from the other authors, and revised by Dotiwala, Small, Li, and Martin, with assistance from Krishnan and Casciano.

Clinical and Economic Burden of Elevated Blood Eosinophils in Patients With and Without Uncontrolled Asthma

BACKGROUND

The European Respiratory Society and American Thoracic Society (ERS/ATS) published guidelines in 2014 for the evaluation and treatment of asthma. These guidelines draw attention to management of patients with asthma that remains uncontrolled despite therapy. One phenotypic characteristic of therapy-resistant asthma is eosinophil elevation. It is important to better understand the burden of care gaps in this patient subgroup in order to support improved treatment strategies in the future.

OBJECTIVE

To quantify the economic burden of asthma patients with and without peripheral blood eosinophil elevation.

METHODS

A retrospective cohort study was conducted using data from patients aged 12 years or older with a diagnosis of asthma using electronic health records of over 2 million patients between 2004-2010. Patients with a diagnosis of chronic obstructive pulmonary disease, Churg Strauss syndrome/Wegener's granulomatosis, eosinophilia, cystic/pulmonary fibrosis, allergic bronchopulmonary aspergillosis, or lung cancer in the 12-month period before the date of asthma diagnosis were excluded. Patients with asthma were followed for 12 months after their initial asthma diagnosis to identify those with controlled versus uncontrolled asthma based on ERS/ATS criteria. Patients with at least 1 peripheral blood eosinophil test result of ≥ 400 cells/µL were classified as those with elevated eosinophils. Total annual paid-claim cost was compared by eosinophil levels within the controlled and uncontrolled asthma subgroups. Costs were adjusted to 2015 U.S. dollars. Patients were stratified by control level, and generalized linear modeling regressions were used to assess the magnitude of increase in cost of the elevated eosinophil group.

RESULTS

A total of 2,701 patients were included in the study, of which 17% had uncontrolled asthma and 21% had elevated eosinophils. The mean total annual cost of patients with uncontrolled asthma was more than 2 times the cost of those with controlled asthma ($18,341 vs. $8,670, P < 0.001). Patients with uncontrolled asthma in the elevated eosinophil group had almost double the total cost ($28,644 vs. $14,188, P = 0.008) compared with those with blood eosinophil levels in a normal range. Similarly, patients classified as those with controlled asthma in the elevated eosinophil group had almost twice the average costs as those without elevated eosinophils ($14,754 vs. $7,203, P < 0.001). Uncontrolled asthma with elevated eosinophils had 4 times greater hospital admissions and over 4 times higher total costs than controlled asthma without elevated eosinophils. Among patients with uncontrolled asthma, patients with elevated eosinophils had a 53% increase in mean cost ($17,723 vs. $11,581, P < 0.001) compared with patients without elevated eosinophils. Among patients with controlled asthma, patients with elevated eosinophils had a 62% increase in mean cost ($8,897 vs. $5,486, P < 0.001) compared with patients without elevated eosinophils.

CONCLUSIONS

Elevated peripheral blood eosinophil level is associated with higher cost irrespective of disease control status.

DISCLOSURES

This study was funded by Teva Pharmaceuticals. Dotiwala and Casciano report consulting and writing fees from Teva Pharmaceuticals for work on this study. Sun is an employee and stockholder of Teva Pharmaceuticals. Li reports consulting fees from eMAX Health. All authors contributed to study design. Dotiwala took the lead in data collection, along with the other authors, and data interpretation was performed primarily by Krishnan, Sun, and Li, along with Casciano and Dotiwala. The manuscript was written by Casciano, Dotiwala, and Li, along with Sun and Krishnan, and revised by Casciano, Dotiwala, Sun, and Li, with assistance from Krishnan.

A prebiotic galactooligosaccharide mixture reduces severity of hyperpnoea-induced bronchoconstriction and markers of airway inflammation

Gut microbes have a substantial influence on systemic immune function and allergic sensitisation. Manipulation of the gut microbiome through prebiotics may provide a potential strategy to influence the immunopathology of asthma. This study investigated the effects of prebiotic Bimuno-galactooligosaccharide (B-GOS) supplementation on hyperpnoea-induced bronchoconstriction (HIB), a surrogate for exercise-induced bronchoconstriction, and airway inflammation. A total of ten adults with asthma and HIB and eight controls without asthma were randomised to receive 5·5 g/d of either B-GOS or placebo for 3 weeks separated by a 2-week washout period. The peak fall in forced expiratory volume in 1 s (FEV1) following eucapnic voluntary hyperpnoea (EVH) defined HIB severity. Markers of airway inflammation were measured at baseline and after EVH. Pulmonary function remained unchanged in the control group. In the HIB group, the peak post-EVH fall in FEV1 at day 0 (-880 (sd 480) ml) was unchanged after placebo, but was attenuated by 40 % (-940 (sd 460) v. -570 (sd 310) ml, P=0·004) after B-GOS. In the HIB group, B-GOS reduced baseline chemokine CC ligand 17 (399 (sd 140) v. 323 (sd 144) pg/ml, P=0·005) and TNF-α (2·68 (sd 0·98) v. 2·18 (sd 0·59) pg/ml, P=0·040) and abolished the EVH-induced 29 % increase in TNF-α. Baseline C-reactive protein was reduced following B-GOS in HIB (2·46 (sd 1·14) v. 1·44 (sd 0·41) mg/l, P=0·015) and control (2·16 (sd 1·02) v. 1·47 (sd 0·33) mg/l, P=0·050) groups. Chemokine CC ligand 11 and fraction of exhaled nitric oxide remained unchanged. B-GOS supplementation attenuated airway hyper-responsiveness with concomitant reductions in markers of airway inflammation associated with HIB.

Noninvasive Respiratory Metabolite Analysis Associated with Clinical Disease in Cetaceans: A Deepwater Horizon Oil Spill Study

Health assessments of wild cetaceans can be challenging due to the difficulty of gaining access to conventional diagnostic matrices of blood, serum and others. While the noninvasive detection of metabolites in exhaled breath could potentially help to address this problem, there exists a knowledge gap regarding associations between known disease states and breath metabolite profiles in cetaceans. This technology was applied to the largest marine oil spill in U.S. history (The 2010 Deepwater Horizon oil spill in the Gulf of Mexico). An accurate analysis was performed to test for associations between the exhaled breath metabolome and sonographic lung abnormalities as well as hematological, serum biochemical, and endocrine hormone parameters. Importantly, metabolites consistent with chronic inflammation, such as products of lung epithelial cellular breakdown and arachidonic acid cascade metabolites were associated with sonographic evidence of lung consolidation. Exhaled breath condensate (EBC) metabolite profiles also correlated with serum hormone concentrations (cortisol and aldosterone), hepatobiliary enzyme levels, white blood cell counts, and iron homeostasis. The correlations among breath metabolites and conventional health measures suggest potential application of breath sampling for remotely assessing health of wild cetaceans. This methodology may hold promise for large cetaceans in the wild for which routine collection of blood and respiratory anomalies are not currently feasible.

Inflammatory biomarkers for asthma endotyping and consequent personalized therapy

INTRODUCTION

We argue that asthma be considered a syndrome caused by multiple inflammatory pathogenic processes. Bronchial hyperresponsiveness, reversible airflow limitation, and chronic airway inflammation characterize asthma pathophysiology. Personalized Medicine, i.e. a tailored management approach, is appropriate for asthma management and is based on the identification of discrete phenotypes and endotypes. Biomarkers can help define phenotypes and endotypes. Several biomarkers have been described in asthma, but most of them are not commonly available or still need external validation. Areas covered: This review presents useful pragmatic biomarkers available in daily clinical practice for assessing airway inflammation in asthmatic patients. Expert commentary: Eosinophil counts and serum allergen-specific IgE assessments are the most reliable biomarkers. Lung function, mainly concerning FEF_25-75, and nasal cytology may be envisaged as ancillary biomarkers in asthma management. In conclusion, biomarkers have a clinical relevance in asthma in identifying asthma endotypes to direct personalized therapy.

Use of electronic medical records and biomarkers to manage risk and resource efficiencies

The migration from paper to electronic medical records (EMRs) was motivated by the administrative need to record, retrieve and process increasing amounts of clinical data in the 1980s. In the intervening period, there has been growing recognition of the potential of such records for achieving care efficiencies, informing clinical decision making and real-life research. EMRs can be used to characterise patient groups, management approaches and differential outcomes. Characterisation can also help with identification of potential biomarkers for future risk determination and likely treatment response. The future heralds even greater opportunities through integration of clinical records and a range of technology-based solutions within a more complete electronic health record (EHR). Through application of algorithms based on identified risk predictors and disease determinants, clinical records could also be used to enable risk stratification of patients to optimise targeted interventions, conserving resources to achieve individual patient and system-wide benefit. In this review, we reflect on the evolution of the EMR and EHR and discuss current and emerging opportunities, particularly with respect to biomarkers and targeting of innovative biologic interventions. We also consider some of the critical issues associated with realising the potential of the EHR as a clinical aid and research tool in an age of emerging technologies.​​​​.

Polymorphism 4G/5G of the plasminogen activator inhibitor 1 gene as a risk factor for the development of allergic rhinitis symptoms in patients with asthma

Plasminogen activator inhibitor-1 (PAI-1) is a glycoprotein which has a role in tissue remodelling after inflammatory processes. The objective is to investigate the frequency of PAI-1 gene polymorphism (4G/5G) in patients with a lung ventilation dysfunction in asthma and allergic rhinitis. Genomic DNA was isolated and genotypes of polymorphism of PAI-1 4G/5G and ABO were determined using the methods of RT-PCR and PCR-SSP. Study group includes 145 adult patients diagnosed with chronic asthma, with all clinically relevant parameters and the laboratory markers of pO₂, IgE and eosinophils in sputum and nasal swab. In the processing of data, appropriate statistical tests (Kolmogorov-Smirnov test, median, interquartile ranges, χ ² and Mann-Whitney U tests) were used. Patients with symptoms of allergic rhinitis were significantly younger and had an almost four time higher levels of IgE (P = 0.001), higher pO₂ (P = 0.002) and PEF (P = 0.036), compared to those who do not have these symptoms. Genotype PAI 4G/4G is significantly more common in patients with allergic rhinitis (28.1% vs. 16.1%; P = 0.017) compared to the genotype 5G/5G. Carriers of the genotype 4G/5G also have a borderline statistical significance. There were no statistically significant difference in the incidence of allergic rhinitis in the carriers of any ABO genotypes. The frequency of PAI genotype 4G/4G is significantly more common in patients with allergic rhinitis. The results suggest that the carriers of at least one 4G allele are at a higher risk for developing symptoms of allergic rhinitis in asthma.

Exhaled nitric oxide in the diagnosis of asthma in adults: a systematic review

OBJECTIVES

To identify and synthesize evidence on the diagnostic accuracy of _FE NO for asthma in adults.

MATERIALS AND METHODS

Systematic searches (nine key biomedical databases and trial registers) were carried out on November 2014. Records were included if they recruited patients with the symptoms of asthma; used a single set of inclusion criteria; measured _FE NO₅₀ in accordance with American Thoracic Society guidelines, 2005 (off-line excluded); reported/allowed calculation of true-positive, true-negative, false-positive and false-negative patients as classified against any reference standard. Study quality was assessed using QUADAS II. Meta-analysis was planned where clinical study heterogeneity allowed. Rule-in and rule-out uses of _FE NO were considered.

RESULTS

A total of 4861 records were identified originally and 1312 in an update. Twenty-seven studies were included. Heterogeneity precluded meta-analysis. Results varied even within subgroups of studies. Cut-off values for the best sum of sensitivity and specificity varied from 12 to 55 p.p.b., but did not produce high accuracy. 100% sensitivity or 100% specificity was reported by some studies indicating potential use as a rule-in or rule-out strategy.

CONCLUSIONS AND CLINICAL RELEVANCE

_FE NO₅₀ had variable diagnostic accuracy even within subgroups of studies with similar characteristics. Diagnostic accuracy, optimal cut-off values and best position for _FE NO₅₀ within a pathway remain poorly evidenced.

Urinary Leukotriene E4 to Determine Aspirin Intolerance in Asthma: A Systematic Review and Meta-Analysis

BACKGROUND

Urinary leukotriene E4 (ULTE4) may be a biomarker that distinguishes aspirin-intolerant asthma from other asthma subtypes.

OBJECTIVE

To estimate the diagnostic testing accuracy of ULTE4 as a marker of aspirin intolerance in patients with asthma using previously published studies.

METHODS

We identified relevant clinical studies from a systematic review of English and non-English articles using MEDLINE, EMBASE, and CENTRAL (inception to February 10, 2015). Articles were screened at the abstract and full-text level by 2 independent reviewers. We included previously published studies that analyzed ULTE4 in human subjects with asthma characterized as having or not having aspirin intolerance on the basis of a specified definition: convincing history of aspirin intolerance, positive aspirin challenge, or both as the criterion standard. Individual-level data points from all included studies were obtained and analyzed.

RESULTS

The search strategy identified 867 potential articles, of which 86 were reviewed at the full-text level and 10 met criteria for inclusion. The sensitivity, specificity, positive predictive value, and negative predictive values of ULTE4 to determine aspirin intolerance in subjects with asthma were 0.55, 0.82, 0.75, and 0.66 (Amersham-enzyme immunoassay); 0.76, 0.77, 0.70, and 0.78 (Cayman-enzyme immunoassay); 0.70, 0.81, 0.86, and 0.79 (mass spectrometry); and 0.81,0.79, 0.65, and 0.88 (radioimmunoassay) at optimal thresholds of 192, 510, 167 to 173, and 66 to 69 pg/mg Cr, respectively. The diagnostic odds ratio for each methodology was 6.0, 11.9, 10.5, and 19.1, respectively.

CONCLUSIONS

ULTE4 is a marker for aspirin-intolerant asthma and could potentially be used as a clinical test to identify the risk of aspirin intolerance in subjects with asthma.

Day-time variation of serum periostin in asthmatic adults treated with ICS/LABA and adults without asthma

BACKGROUND

We aimed to determine the effect of sampling time during the day on serum periostin levels in adult participants with and without asthma.

METHODS

Serum periostin was measured at 2-h intervals from 0800 to 1800 h in 16 adult participants with stable asthma prescribed inhaled corticosteroid and long-acting beta-agonist therapy, and in 16 otherwise healthy participants without asthma. Mixed linear models were used to compare time zero (08:00 h) with subsequent measurement time for serum periostin for both groups.

RESULTS

In both asthma and non-asthma, the mean (SD) serum periostin levels continuously reduced during the day from 53.5 (13.6) ng/mL at 0800 h to 50.9 (13.4) ng/mL at 1800 h (difference log periostin -0.05, P ≤ 0.001) and 50.5 (13.0) ng/mL at 0800 h to 46.2 (11.5) ng/mL at 1800 h (difference log periostin -0.08, P ≤ 0.001) respectively.

CONCLUSIONS

Periostin values are higher in the morning compared with the afternoon in asthmatic and non-asthmatic adults. The small magnitude of the variation in serum periostin levels suggests that the time of day in which the serum periostin measurements are made is unlikely to influence treatment decisions if a specific serum periostin level is used to predict treatment responsiveness. Trial registration Australia New Zealand Trials Registry (ACTRN12614000072617).

Chyawanprash: A review of therapeutic benefits as in authoritative texts and documented clinical literature

ETHNOPHARMACOLOGICAL RELEVANCE

Chyawanprash (CP), a traditional immune booster recipe, has a long history of ethnic origin, development, household preparation and usage. There are even mythological stories about the origin of this recipe including its nomenclature. In the last six decades, CP, because of entrepreneurial actions of some research Vaidyas (traditional doctors) has grown to industrial production and marketing in packed forms to a large number of consumers/patients like any food or health care product. Currently, CP has acquired a large accepted user base in India and in a few countries out-side India.

AIM OF THE STUDY

Authoritative texts, recognized by the Drugs and Cosmetics Act of India, describe CP as an immunity enhancer and strength giver meant for improving lung functions in diseases with compromised immunity. This review focuses on published clinical efficacy and safety studies of CP for correlation with health benefits as documented in the authoritative texts, and also briefs on its recipes and processes.

MATERIALS AND METHODS

Authoritative texts were searched for recipes, processes, and other technical details of CP. Labels of marketing CP products (Indian) were studied for the health claims. Electronic search for studies of CP on efficacy and safety data were performed in PubMed/MEDLINE and DHARA (Digital Helpline for Ayurveda Research Articles), and Ayurvedic books were also searched for clinical studies.

RESULTS

The documented clinical studies from electronic databases and Ayurvedic books evidenced that individuals who consume CP regularly for a definite period of time showed improvement in overall health status and immunity. However, most of the clinical studies in this review are of smaller sample size and short duration. Further, limitation to access and review significant data on traditional products like CP in electronic databases was noted.

CONCLUSIONS

Randomized controlled trials of high quality with larger sample size and longer follow-up are needed to have significant evidence on the clinical use of CP as immunity booster. Additional studies involving measurement of current biomarkers of immunity pre- and post-consumption of the product as well as benefits accruing with the use of CP as an adjuvant are suggested.