Severe exacerbations predict excess lung function decline in asthma

[Woman's asthma throughout life: Towards a personalized management?]

In a woman's life, asthma can affect her in a variety of ways, with the onset of premenstrual asthma currently under-diagnosed. It is estimated that about 20% of women with asthma have premenstrual asthma, which is more common in patients with severe asthma. Women with asthma are at high risk of exacerbations and of severe asthma. Asthma is the most common chronic disease during pregnancy with potential maternal and foetal complications. Asthma medications are safe for the foetus and it is essential to continue pre-existing treatment and adapt it to the progress of asthma during the pregnancy. Sex steroids modulate the structure and function of bronchial and immune cells. Understanding their role in asthma pathogenesis is complicated by the ambivalent effects of bronchodilating and pro-inflammatory oestrogens as well as the diversity of response to their association with progesterone. Menopausal asthma is a clinical entity and is part of one of the phenotypes of severe non-allergic and low steroid-sensitive asthma. Targeted assessment of the domestic and professional environment allows optimization of asthma management.

A systematic review of methodology used in the development of prediction models for future asthma exacerbation

Background

Clinical prediction models are widely used to guide medical advice and therapeutic interventions. Asthma is one of the most common chronic diseases globally and is characterised by acute deteriorations. These exacerbations are largely preventable, so there is interest in using clinical prediction models in this area. The objective of this review was to identify studies which have developed such models, determine whether consistent and appropriate methodology was used and whether statistically reliable prognostic models exist.

Methods

We searched online databases MEDLINE (1948 onwards), CINAHL Plus (1937 onwards), The Cochrane Library, Web of Science (1898 onwards) and ClinicalTrials.gov, using index terms relating to asthma and prognosis. Data was extracted and assessment of quality was based on GRADE and an early version of PROBAST (Prediction study Risk of Bias Assessment Tool). A meta-analysis of the discrimination and calibration measures was carried out to determine overall performance across models.

Results

Ten unique prognostic models were identified. GRADE identified moderate risk of bias in two of the studies, but more detailed quality assessment via PROBAST highlighted that most models were developed using highly selected and small datasets, incompletely recorded predictors and outcomes, and incomplete methodology. None of the identified models modelled recurrent exacerbations, instead favouring either presence/absence of an event, or time to first or specified event. Preferred methodologies were logistic regression and Cox proportional hazards regression.

The overall pooled c-statistic was 0.77 (95% confidence interval 0.73 to 0.80), though individually some models performed no better than chance. The meta-analysis had an I² value of 99.75% indicating a high amount of heterogeneity between studies. The majority of studies were small and did not include internal or external validation, therefore the individual performance measures are likely to be optimistic.

Conclusions

Current prognostic models for asthma exacerbations are heterogeneous in methodology, but reported c-statistics suggest a clinically useful model could be created. Studies were consistent in lacking robust validation and in not modelling serial events. Further research is required with respect to incorporating recurrent events, and to externally validate tools in large representative populations to demonstrate the generalizability of published results.

Elevated eosinophils, IL5 and IL8 in induced sputum in asthma patients with accelerated FEV1 decline

BACKGROUND

Some patients with asthma present with accelerated lung function decline. This phenomenon is mostly associated with severe exacerbations and with poor asthma control.

OBJECTIVE

Our aim was to detect the extent of FEV1 decline in patients with mild asthma and to discriminate clinical, functional and inflammatory factors associated with accelerated FEV1 decline.

METHODS

We recruited 50 patients with mild asthma for pulmonary function testing and induced sputum sampling 12-15 years after the initial diagnosis. In 33 patients, from whom sputum of a good quality was obtained, inflammatory cells were counted and concentrations of cytokines IL-2, IL-4, IL-5, IL-8, IL-10, IFN-γ, angiogenin and VEGF in the sputum were measured by cytometric bead array.

RESULTS

Eighteen of 33 patients presented with accelerated FEV1 decline of more than 30 ml/year, with a mean (SEM) of 43.2 (3.9) ml/year, compared to 15 control patients with a FEV1 decline of 14.4 (2.1) ml/year. In the accelerated FEV1 decline group, we found elevated sputum levels of IL5 with a median (IQR) of 1.8 (0.4-3.2) pg/ml vs. 0.2 (0.1-1.2) pg/ml, p = 0.04; IL8 with a mean (SEM) of 1503 (194) pg/ml vs. 938 (177) pg/ml, p = 0.04; and eosinophils with a median (IQR) of 223 (41-1020) cells/μl vs. 39 (1-190) cells/μl, p = 0.03. No significant differences in other measured parameters were detected between the two groups.

CONCLUSION

Elevated sputum eosinophils, IL5 and IL8, which have a potential to stimulate airway remodelling, might be a useful non-invasive biomarkers and therapeutic targets of accelerated FEV1 decline in asthma patients.

Nebulized step-down budesonide vs. fluticasone in infantile asthma: A retrospective cohort study

The United States Food and Drug Administration has approved budesonide in infantile asthma but nebulization of infants under budesonide has the risk of relapse of asthma. The objective of the present study was to compare the effectiveness and safety of fluticasone step-down treatment with budesonide step-down treatment in infantile asthma. The data of 778 infants with confirmed asthma were included in the analysis. Infants who had received nebulized 500 µg budesonide twice daily for 6 weeks followed by 250 µg budesonide twice daily for 6 weeks were included in the BS group (n=389), while infants who had received nebulized 250 µg fluticasone twice daily for 6 weeks followed by 125 µg fluticasone twice daily for 6 weeks were included in the FC group (n=389). The data of lung function tests and a safety study were collected and analyzed. Budesonide treatment achieved a reduced specific airway resistance (sRaw; 1.28±0.11 vs. 1.21±0.10 kPa/sec; P<0.0001, q=13.45) and improved forced expiratory volume in 1 sec (FEV1; 0.977±0.068 vs. 0.997±0.085 l/sec; P<0.0001, q=5.54). In addition, fluticasone treatment achieved a reduced sRaw (1.27±0.1 vs. 1.23±0.11 kPa/sec, P<0.0001, q=7.39) and improved FEV1 (0.971±0.069 vs. 0.992±0.085 l/sec; P=0.0003, q=5.46). Of note, the efficacy of budesonide to reduce sRaw (P=0.008, q=3.69) and improve FEV1 (P<0.0001, q=6.93) was greater than that of fluticasone. The budesonide treatment group had more post-treatment symptom-free days than the fluticasone treatment group (165.56±23.15 vs. 112.21±9.45 days; P<0.0001). The step-down approach of budesonide nebulization may better support the functional and clinical outcomes with an increased number of post-treatment symptom-free days compared with fluticasone in infantile asthma (level of evidence, 3).

Airway function throughout the lifespan: Pediatric origins of adult respiratory disease

Chronic obstructive pulmonary disease (COPD) is a leading cause of disability and death of adults in the USA and worldwide. While environmental factors such as smoking and air pollution are major contributors to COPD, pediatric respiratory disease and more specifically early childhood wheezing are frequent predisposing factors. It is therefore possible that aggressive prevention and treatment of childhood respiratory illness may modify adult COPD risk. This article reviews some of the physiological factors that may explain the pediatric origins of childhood lung disease. One such factor is the "tracking" of normal lung function which occurs with growth. The maximal expiratory flow volume (MEFV) curve is an ideally suited tool to monitor tracking of airway function over the lifespan, as its relative effort independence makes it highly reliable. Study of the MEFV curve has demonstrated that individuals with similar lung volumes can have large differences in maximal flows, reflecting a disconnection between airway and lung growth ("dysanapsis"). Less than average airway size due to dysanaptic airway growth or airway remodeling may be independent risk factors for the development of COPD and the asthma/COPD overlap syndrome in adult life. There are intriguing early data suggesting that perhaps at least some of this risk is modifiable by improving asthma control with inhaled corticosteroids and minimizing asthma exacerbations.

The equine asthma model of airway remodeling: from a veterinary to a human perspective

Human asthma is a complex and heterogeneous disorder characterized by chronic inflammation, bronchospasm and airway remodeling. The latter is a major determinant of the structure-function relationship of the respiratory system and likely contributes to the progressive and accelerated decline in lung function observed in patients over time. Corticosteroids are the cornerstone of asthma treatment. While their action on inflammation and lung function is well characterized, their effect on remodeling remains largely unknown. An important hindrance to the study of airway remodeling as a major focus in asthma research is the lack of reliable non-invasive biomarkers. In consequence, the physiologic and clinical consequences of airway wall thickening and altered composition are not well understood. In this perspective, equine asthma provides a unique and ethical (non-terminal) preclinical model for hypothesis testing and generation. Severe equine asthma is a spontaneous disease affecting adult horses characterized by recurrent and reversible episodes of disease exacerbations. It is associated with bronchoalveolar neutrophilic inflammation, bronchospasm, and excessive mucus secretion. Severe equine asthma is also characterized by bronchial remodeling, which is only partially improved by prolonged period of disease remission induced by therapy or antigen avoidance strategies. This review will focus on the similarities and differences of airway remodeling in equine and human asthma, on the strengths and limitations of the equine model, and on the challenges the model has to face to keep up with human asthma research.

IL-33 blockade affects mediators of persistence and exacerbation in a model of chronic airway inflammation

BACKGROUND

Severe inflammatory airway diseases are associated with inflammation that does not resolve, leading to structural changes and an overall environment primed for exacerbations.

OBJECTIVE

We sought to identify and inhibit pathways that perpetuate this heightened inflammatory state because this could lead to therapies that allow for a more quiescent lung that is less predisposed to symptoms and exacerbations.

METHODS

Using prolonged exposure to house dust mite in mice, we developed a mouse model of persistent and exacerbating airway disease characterized by a mixed inflammatory phenotype.

RESULTS

We show that lung IL-33 drives inflammation and remodeling beyond the type 2 response classically associated with IL-33 signaling. IL-33 blockade with an IL-33 neutralizing antibody normalized established inflammation and improved remodeling of both the lung epithelium and lung parenchyma. Specifically, IL-33 blockade normalized persisting and exacerbating inflammatory end points, including eosinophilic, neutrophilic, and ST2⁺CD4⁺ T-cell infiltration. Importantly, we identified a key role for IL-33 in driving lung remodeling because anti-IL-33 also re-established the presence of ciliated cells over mucus-producing cells and decreased myofibroblast numbers, even in the context of continuous allergen exposure, resulting in improved lung function.

CONCLUSION

Overall, this study shows that increased IL-33 levels drive a self-perpetuating amplification loop that maintains the lung in a state of lasting inflammation and remodeled tissue primed for exacerbations. Thus IL-33 blockade might ameliorate symptoms and prevent exacerbations by quelling persistent inflammation and airway remodeling.

Attack, flare-up, or exacerbation? The terminology preferences of patients with severe asthma

Background: People with severe asthma experience frequent life-threatening acute asthma events. A Lancet commission recently highlighted that terms "exacerbations" and "flare-ups" are seen to trivialize these episodes and recommended use of the term "attacks." Clinicians however, preferentially use the term "exacerbation" and some guidelines recommend the use of "exacerbation" with patients.Objective: This descriptive qualitative study aimed to understand the patient's experience and perspectives of these events and language used to describe them.Methods: Semi-structured one-on-one interviews were conducted in Australia and the UK in 18 people with severe asthma and 10 with mild-moderate asthma regarding their usage and preferences for such terminologies. Additionally, nine people with severe asthma participated in two focus groups in which use of preferred terminology was explored.Results: Mean age of participants was 57 ± 14.03 yr and 65% were female. A total 67 quotes were recorded in which 16 participants with severe asthma spontaneously used either the term "attack," "flare-up" and/or "exacerbation." Of these quotes, all 16 participants used "attack," one used all three terms and two used both "exacerbation" and "attack." The term "attack" was used to describe frightening events having major impacts on participant's lives, whereas "exacerbation" and "flare-up" were used to refer to both severe and mild, transient asthma-related events.Conclusion: Usage of the term "attack" was preferred by patients with severe asthma. Adoption of this language may assist in patient-clinician communication and disease management and outcomes. Wider stakeholder engagement is needed to confirm this suggestion. AbbreviationsFEV₁forced expiratory volume in 1 secondATSAmerican Thoracic SocietyERSEuropean Respiratory SocietyACQAsthma Control QuestionnaireICSinhaled corticosteroidsOCSoral corticosteroidsBTSBritish Thoracic SocietySIGNScottish Intercollegiate Guidelines NetworkWAPwritten action plan.

Genes and Pathways Regulating Decline in Lung Function and Airway Remodeling in Asthma

Asthma is a common disorder of the airways characterized by airway inflammation and by decline in lung function and airway remodeling in a subset of asthmatics. Airway remodeling is characterized by structural changes which include airway smooth muscle hypertrophy/hyperplasia, subepithelial fibrosis due to thickening of the reticular basement membrane, mucus metaplasia of the epithelium, and angiogenesis. Epidemiologic studies suggest that both genetic and environmental factors may contribute to decline in lung function and airway remodeling in a subset of asthmatics. Environmental factors include respiratory viral infection-triggered asthma exacerbations, and tobacco smoke. There is also evidence that several asthma candidate genes may contribute to decline in lung function, including ADAM33, PLAUR, VEGF, IL13, CHI3L1, TSLP, GSDMB, TGFB1, POSTN, ESR1 and ARG2. In addition, mediators or cytokines, including cysteinyl leukotrienes, matrix metallopeptidase-9, interleukin-33 and eosinophil expression of transforming growth factor-β, may contribute to airway remodeling in asthma. Although increased airway smooth muscle is associated with reduced lung function (i.e. forced expiratory volume in 1 second) in asthma, there have been few long-term studies to determine how individual pathologic features of airway remodeling contribute to decline in lung function in asthma. Clinical studies with inhibitors of individual gene products, cytokines or mediators are needed in asthmatic patients to identify their individual role in decline in lung function and/or airway remodeling.

The efficacy and safety of long-term add-on treatment of azithromycin in asthma: A systematic review and meta-analysis

AIM

Effects of azithromycin on asthma reported in clinical trials are less consistent. We aimed to further clarify the efficacy and safety of azithromycin in treatment of asthma.

METHODS

The protocol registration number was CRD42017074318 (http://www.crd.york.ac.uk/Prospero). We searched PubMed, EMBASE, Cochrane databases, China National Knowledge Internet (CNKI), and Wanfang databases for the randomized controlled trials (RCTs) with prolonged treatment of azithromycin for more than 3 weeks. Random-effects or fixed-effects model was applied to calculate risk ratio (RR) and mean difference (MD) for dichotomous and continuous data respectively.

RESULTS

A total of eight studies were included for analysis. The pooled result of adjunctive azithromycin therapy in asthma showed a small, but statistically significant increase in forced expiratory volume in one second (FEV1) (MD = 0.06, 95% confidence interval [CI]: 0.01-0.12, P = .02), but no significant differences in exacerbation frequency (MD = -0.42, 95%CI: -1.13 to 0.30, P = .25) and peak expiratory flow (PEF) (MD = 0.20, 95% CI: -0.05 to 0.44, P = .12), fractional exhaled nitric oxide (FeNO) (MD = 4.12, 95% CI: -2.06 to 10.30, P = .19), asthma quality of life questionnaire (AQLQ) (MD: 0.05, 95% CI: -0.17 to 0.28, P = .65), asthma control questionnaire (ACQ) (MD: -0.03, 95% CI: -0.21 to 0.15, P = .75). The subgroup analysis revealed that azithromycin could decrease FeNO among Asian asthma (MD = 15.04, 95% CI: 6.18-23.90, P = .0009).

CONCLUSIONS

Add-on therapy of azithromycin in asthma patients could improve the FEV1, but failed to improve asthma exacerbations, PEF, ACQ, AQLQ, and FeNO. Subgroup analysis indicated that azithromycin could improve FeNO in Asian group asthmatics.

Long-term Safety and Clinical Benefit of Mepolizumab in Patients With the Most Severe Eosinophilic Asthma: The COSMEX Study

PURPOSE

The goal of this study was to assess the long-term safety and efficacy of mepolizumab in patients with the most severe eosinophilic asthma.

METHODS

This multicenter, open-label, long-term, Phase IIIb study (COSMEX [COSMOS Extension]; 201312/NCT02135692) enrolled patients from the 52-week, open-label extension study COSMOS (A Study to Determine Long-term Safety of Mepolizumab in Asthmatic Subjects) that previously enrolled patients from the double-blinded, placebo-controlled Phase III studies MENSA (Mepolizumab as Adjunctive Therapy in Patients with Severe Asthma) and SIRIUS (Steroid Reduction with Mepolizumab Study). To enter COSMEX, patients had to have life-threatening/seriously debilitating asthma before entering MENSA or SIRIUS and to have completed these previous studies with demonstrated improvement while receiving mepolizumab. In COSMEX, patients received mepolizumab 100 mg subcutaneously every 4 weeks as add-on therapy for up to 172 weeks. Primary endpoints were adverse event frequency and exacerbation rate per year; also assessed were forced expiratory volume in 1 s, Asthma Control Questionnaire-5 score, and daily oral corticosteroid (OCS) use.

FINDINGS

Of the 340 patients enrolled, 339 received mepolizumab; median treatment duration within this extension study was 2.2 years, equating to 718 patient-years of additional exposure. No new safety signals were identified. Patients receiving mepolizumab throughout this study and previous studies had lasting reductions in exacerbation rate and daily OCS use and improvements in forced expiratory volume in 1 s and Asthma Control Questionnaire-5 score. In COSMEX, the on-treatment exacerbation rate (95% CI) was 0.93 (0.81-1.06) event/year for clinically significant exacerbations, 0.13 (0.10-0.18) event/year for exacerbations requiring hospitalization/emergency department visit, and 0.07 (0.05-0.10) event/year for exacerbations requiring hospitalization. In patients requiring systemic/oral corticosteroids with ≥128 weeks of continuous enrollment across SIRIUS, COSMOS, and COSMEX, mepolizumab maintained the median daily OCS dose at 1.3-2.8 mg during COSMEX, with additional patients no longer requiring OCS after extended mepolizumab treatment.

IMPLICATIONS

This study indicates that long-term mepolizumab treatment is well tolerated and associated with sustained clinical benefits in patients with severe eosinophilic asthma. ClinicalTrials.gov identifier: NCT02135692.

Options of immunotherapeutic treatments for children with asthma

Introduction: Asthma is the most common chronic disease in children. Avoiding triggers, and pharmacologic treatment with short acting beta-agonist, inhaler corticosteroids and anti-leukotriene are often enough to obtain symptoms control. Nevertheless, there is a subset of children with severe asthma and poor symptom control despite maximal therapy. In these patients, anti-IgE and anti-IL5 monoclonal antibodies are suggested as the fifth step of Global Initiative for Asthma guidelines. Area covered: Immunotherapeutic treatments are now suggested for asthma management. This article will discuss the available evidence on allergen immunotherapy and biologic drugs in pediatric asthma treatment. Expert opinion: Previously published studies demonstrated a good efficacy and safety profile of Allergen Immunotherapy in patients with mild-moderate asthma and sensitization to one main allergen. New understanding of mechanisms underlying severe asthma inflammation has allowed the identifications of specific biomarkers guiding the clinician in the choice of patient specific drug. Among the suggested immunotherapeutic options, omalizumab (blocking IgE) remains the first choice for atopic 'early onset' asthma in patients aged over 6 years. Instead, mepolizumab (blocking the IL5 ligand) should be considered for 'eosinophilic' asthma. Other biologic drugs are under consideration but data on the pediatric population are still lacking.

It is time to change the way we manage mild asthma: an update in GINA 2019

Asthma is a heterogeneous lung disease, usually characterised by chronic airway inflammation. Although evidence-based treatments are available in most countries, asthma control remains suboptimal, and asthma-related deaths continue to be an ongoing concern. Generally, it is believed that between 50 to 75% of patients with asthma can be considered as having mild asthma.Previous versions of Global Initiative for Asthma (GINA) suggested that mild asthma in adults can be well managed with either reliever medications, for example, short-acting beta2 agonists (SABA) alone or with the additional use of controllers such as regular low-dose inhaled corticosteroids (ICS). Given the low frequency or non-bothersome nature of symptoms in mild asthma, patients' adherence towards their controller medications, especially to ICS is usually not satisfactory. Such patients often rely on SABA alone to relieve symptoms, which may contribute to SABA over-reliance. Overuse of relievers such as SABAs has been associated with poor asthma outcomes, such as exacerbations and even deaths. The new GINA 2019 asthma treatment recommendations represent significant shifts in asthma management at Steps 1 and 2 of the 5 treatment steps. The report acknowledges an emerging body of evidence suggesting the non-safety of SABAs overuse in the absence of concomitant controller medications, therefore does not support SABA-only therapy in mild asthma and has included new off-label recommendations such as symptom-driven (as-needed) low dose ICS-formoterol and "low dose ICS taken whenever SABA is taken".The GINA 2019 report highlights significant updates in mild asthma management and these recommendations represent a clear deviation from decades of clinical practice mandating the use of symptom-driven SABA treatment alone in those with mild asthma. While the new inclusions of strategies such as symptom-driven (as-needed) ICS-formoterol and "ICS taken whenever SABA is taken" are based on several key trials, data in this context are still only emergent data, with clear superiority of as needed ICS-formoterol combinations over maintenance ICS regimens yet to be established for valid endpoints. Nevertheless, current and emerging data position the clinical asthma realm at a watershed moment with imminent changes for the way we manage mild asthma likely in going forward.

Asthma progression and mortality: the role of inhaled corticosteroids

Overall, asthma mortality rates have declined dramatically in the last 30 years, due to improved diagnosis and to better treatment, particularly in the 1990s following the more widespread use of inhaled corticosteroids (ICSs). The impact of ICS on other long-term outcomes, such as lung function decline, is less certain, in part because the factors associated with these outcomes are incompletely understood. The purpose of this review is to evaluate the effect of pharmacological interventions, particularly ICS, on asthma progression and mortality. Furthermore, we review the potential mechanisms of action of pharmacotherapy on asthma progression and mortality, the effects of ICS on long-term changes in lung function, and the role of ICS in various asthma phenotypes.Overall, there is compelling evidence of the value of ICS in improving asthma control, as measured by improved symptoms, pulmonary function and reduced exacerbations. There is, however, less convincing evidence that ICS prevents the decline in pulmonary function that occurs in some, although not all, patients with asthma. Severe exacerbations are associated with a more rapid decline in pulmonary function, and by reducing the risk of severe exacerbations, it is likely that ICS will, at least partially, prevent this decline. Studies using administrative databases also support an important role for ICS in reducing asthma mortality, but the fact that asthma mortality is, fortunately, an uncommon event makes it highly improbable that this will be demonstrated in prospective trials.

Correlations of severity of asthma in children with body mass index, adiponectin and leptin

Background

This study aims to investigate the correlations of asthma in children with body mass index (BMI), adiponectin, and leptin.

Methods

A total of 122 children with asthma in our hospital from January 2017 to February 2018 were randomly selected and divided into control group (normal) and observation group (BMI > 28 kg/m²) according to BMI. BMI, adiponectin, and leptin levels between the two groups were measured and compared, and correlations of disease grade with BMI, adiponectin, or leptin were analyzed. Moreover, risk factors for asthma in children were also identified.

Results

Body mass index, leptin level, forced vital capacity (FVC), FVC%, and forced expiratory volume in 1s (FEV1)/FVC in observation group were significantly higher than those in control group (P < 0.05), while the adiponectin level, forced expiratory capacity in 1s (FEC1), and FEV1% in observation group were significantly lower than those in control group (P < 0.05). The amount of severe patients in observation group was much larger than that in control group. The severity of disease was positively correlated with BMI and leptin and negatively correlated with adiponectin. BMI, adiponectin, and leptin were identified as risk factors for asthma in children.

Conclusion

Adiponectin, leptin, and BMI are involved in the pathogenesis of asthma in children, suggesting they might be therapeutic targets for clinical treatment.

Chitinase-like protein YKL-40 correlates with inflammatory phenotypes, anti-asthma responsiveness and future exacerbations

Background

Asthma is a heterogeneous chronic airway disease, which may be classified into different phenotypes. YKL-40 is a chitin-binding glycoprotein with unclear functions, but its expression is associated with inflammation and tissue remodeling. However, few studies have explored whether YKL-40 is associated with inflammatory phenotypes of asthma.

Methods

The study had two parts. Study I (n = 115) was a one-year prospective cohort designed to explore the relationship of serum YKL-40 levels with inflammatory phenotypes of asthma at baseline, and during exacerbations. Study II (n = 62) was a four-week prospective cohort designed to define whether serum YKL-40 levels could predict responses to a fixed anti-asthma regimen. YKL-40, IL-6 and CCL22 levels were detected using ELISA, and a sputum inflammatory panel (including IL-1β, IL-5, IL-8 and TNF-α) was assessed using Luminex-based MILLIPLEX assay.

Results

Study I: Serum YKL-40 levels in non-eosinophilic asthma (NEA) i.e. neutrophilic (47.77 [29.59, 74.97] ng/mL, n = 40) and paucigranulocytic (47.36 [28.81, 61.68] ng/mL, n = 31) were significantly elevated compared with eosinophilic asthma (31.05 [22.41, 51.10] ng/mL, n = 44) (P = 0.015). Serum YKL-40levels positively correlated with blood neutrophils, sputum IL-1β and plasma IL-6 but negatively correlated with serum IgE and blood eosinophils (all P ≤ 0.05). Baseline YKL-40 levels predicted moderate to severe exacerbations within a one-year period (aOR = 4.13, 95% CI = [1.08, 15.83]). Study II: Serum YKL-40 was an independent biomarker of negative responses to anti-asthma regimens (adjusted Odds Ratio [aOR] = 0.82, 95% CI = [0.71, 0.96].

Conclusions

These studies show that YKL-40 is a non-type 2 inflammatory signature for NEA, which could predict responsiveness or insensitivity to anti-asthma medications and more exacerbations. Further studies are needed to assess whether monitoring YKL-40 levels could provide potential implications for clinical relevance.

Electronic supplementary material

The online version of this article (10.1186/s12931-019-1051-9) contains supplementary material, which is available to authorized users.

Asthma in the Primary Care Setting

Asthma is one of the commonest respiratory diseases in the United States, affecting approximately 8% of adults. This article reviews the epidemiology, diagnosis, and treatment of asthma, with integration of recommendations from professional societies, with special attention to differential diagnosis. A framework for outpatient management of patients with asthma is presented, including indications for subspecialist referral. With integration of objective diagnostic information, systematic approach through modification of disease triggers and adjustment of controller medications, and patient empowerment to respond to varying symptoms using an asthma action plan, most individuals with asthma are successfully managed in the primary care setting.

Increase in blood eosinophils during follow-up is associated with lung function decline in adult asthma

BACKGROUND

Asthma is associated with accelerated rate of lung function (FEV₁) decline.

OBJECTIVE

To determine predictive factors associated with FEV₁ decline in adult asthma.

METHODS

A retrospective study was conducted in 229 asthmatics recruited from the University Asthma Clinic of Liege. Subjects had at least two visits with post-bronchodilation (post-BD) FEV₁ and minimum one year between them. A multivariable linear regression analysis was conducted in order to come up with factors associated with lung function decline.

RESULTS

Post-BD FEV₁ decline in % predicted. y^-1 was 0.2 (95%CI -2.0 to 2.8) in the overall population. Our population was made up of mild to moderate asthmatics [1] for 58%, aged 50 (41-60) years old, 62% were female and 59% were atopic. Median ICS dose was 1000 μg beclomethasone equivalent (CFC)/day with 81% treated at baseline. Time between visits was 46.8 ± 32.1 months. The univariate linear regression analysis revealed a negative association between % predicted FEV₁ decline and baseline ACQ (p < 0.0001) and blood eosinophils (% and/mm³) (p < 0.0001 and p < 0.0001). A positive association was found between % predicted FEV₁ decline and baseline pre-BD FEV1 (mL) values (p = 0.001), blood neutrophils (%) (p = 0.02), change in blood eosinophils (%) (p < 0.0001), time between visits (months) (p < 0.0001). The predictive variables for accelerated decline highlighted by the multivariable analysis (r² = 0.39) were change in blood eosinophils (%) over time (p = 0.002) and time between visits (months) (p < 0.0001).

CONCLUSION

These findings highlight a new value for blood eosinophil counts as their increase over time predicts greater lung function decline in asthma.

[New approaches of inhaled steroid asthma management in mild to moderate asthma]

Inhaled corticosteroids (ICS) are the cornerstone of the management of asthma. Daily use allows to reduce mortality, intensity and frequency of exacerbations, to increase the control of symptoms of asthma and the quality of life of asthmatics patients and to reduce the decline of the lung function. A daily use of a weak dose of ICS allows to control the symptoms of asthma of the vast majority of mild to moderate asthmatics patients who account for about 75-80 % of the French asthmatic patients. An add-on strategy with a combination by ICS/LABA allows to decrease by 20 % the risk of an exacerbation compared with a treatment by CSI in monotherapy. "SMART" which consists in using a fixed ICS/LABA combination as a maintenance and reliever therapy had showed better results in the prevention of exacerbations that the use of the same combination associated with a SABA as a reliever therapy. This strategy is recommended by GINA at the same level of proof as the classical treatment. An "on-demand" use of a ICS/LABA combination according to symptoms is clearly less efficacious in terms of control of the symptoms than the classical strategy by ICS/LABA; but both strategies are identical in terms of prevention of exacerbations. The daily dose of ICS is 4 to 5 times less than in the daily ICS group. The clinical effectiveness and cost-effectiveness of a standard asthma self-management plan that advises patients to temporarily quadrupling the dose of ICS in case of asthma worsening can be an alternative and allow to reduce 20 % of clinically important asthma exacerbations.

A meta-analysis of anti-interleukin-13 monoclonal antibodies for uncontrolled asthma

More and more clinical trials have tried to assess the clinical benefit of anti-interleukin (IL)-13 monoclonal antibodies for uncontrolled asthma. The aim of this study is to evaluate the efficacy and safety of anti-IL-13 monoclonal antibodies for uncontrolled asthma. Major databases were searched for randomized controlled trials comparing the anti-IL-13 treatment and a placebo in uncontrolled asthma. Outcomes, including asthma exacerbation rate, forced expiratory volume in 1 second (FEV1), Asthma Quality of Life Questionnaire (AQLQ) scores, rescue medication use, and adverse events were extracted from included studies for systematic review and meta-analysis. Five studies involving 3476 patients and two anti-IL-13 antibodies (lebrikizumab and tralokinumab) were included in this meta-analysis. Compared to the placebo, anti-IL-13 treatments were associated with significant improvement in asthma exacerbation, FEV1 and AQLQ scores, and reduction in rescue medication use. Adverse events and serious adverse events were similar between two groups. Subgroup analysis showed patients with high periostin level had a lower risk of asthma exacerbation after receiving anti-IL-13 treatment. Our study suggests that anti-IL-13 monoclonal antibodies could improve the management of uncontrolled asthma. Periostin may be a good biomarker to detect the specific subgroup who could get better response to anti-IL-13 treatments. In view of blocking IL-13 alone is possibly not enough to achieve asthma control because of the overlapping pathophysiological roles of IL-13/IL-4 in inflammatory pathways, combined blocking of IL-13 and IL-4 with monoclonal antibodies may be more encouraging.

[Asthma exacerbations in adults: Preventing and treat]

Exacerbations of asthma are still responsible for 900 deaths per year in France, most of which are considered preventable. They have a major impact on the quality of life of patients and are responsible for a large part of the socio-economic cost of asthma in France. Exacerbations of asthma can be partly prevented by inhaled corticosteroid treatment as controller therapy, at a dose adapted to the level of control of symptoms and the management of aggravating factors. Every patient should benefit from a written action plan that allows them to start oral corticosteroid therapy as soon as possible during an exacerbation. The treatment combines short-acting bronchodilators with systemic corticosteroids. Systemic antibiotic therapy has no place in the treatment of exacerbations. The patient must be seen early in the course of an exacerbation of asthma to review all of his follow-up.

Factors associated with exacerbations among adults with asthma according to electronic health record data

BACKGROUND

Asthma is a chronic inflammatory lung disease that affects 18.7 million U.S. adults. Electronic health records (EHRs) are a unique source of information that can be leveraged to understand factors associated with asthma in real-life populations. In this study, we identify demographic factors and comorbidities associated with asthma exacerbations among adults according to EHR-derived data and compare these findings to those of epidemiological studies.

METHODS

We obtained University of Pennsylvania Hospital System EHR-derived data for asthma encounters occurring between 2011 and 2014. Regression analyses were performed to model asthma exacerbation frequency as explained by age, sex, race/ethnicity, health insurance type, smoking status, body mass index (BMI) and various comorbidities. We analyzed data from the National Health and Nutrition Examination Survey (NHANES) from 2001 to 2012 to compare findings with those from the EHR-derived data.

RESULTS

Based on data from 9068 adult patients with asthma, 33.37% had at least one exacerbation over the four-year study period. In a proportional odds logistic regression predicting number of exacerbations during the study period (levels: 0, 1-2, 3-4, 5+ exacerbations), after controlling for age, race/ethnicity, sex, health insurance type, and smoking status, the highest odds ratios (ORs) of significantly associated factors were: chronic bronchitis (2.70), sinusitis (1.50), emphysema (1.39), fluid and electrolyte disorders (1.35), class 3 obesity (1.32), and diabetes (1.28). An analysis of NHANES data showed associations for class 3 obesity, anemia and chronic bronchitis with exacerbation frequency in an adjusted model controlling for age, race/ethnicity, sex, financial class and smoking status.

CONCLUSIONS

EHR-derived data is helpful to understand exacerbations in real-life asthma patients, facilitating design of detailed studies and interventions tailored for specific populations.

Treatable traits in acute exacerbations of chronic airway diseases

Acute exacerbations of chronic airway disease are common occurrences that cause a major burden of illness. Acute exacerbations are associated with impaired health status, increased lung function decline, hospitalization and increased risk of death. Exacerbation avoidance is a major priority. Despite this goal, exacerbations continue to occur and the need for effective models of care that optimize patient outcomes are urgently needed. 'Treatable Traits' is an approach to personalized medicine that has been proposed for the management of airway diseases. The treatable traits approach allows for the recognition of clinically important, identifiable and treatable disease characteristics, followed by targeted and individualized treatment interventions to address each trait. We review the literature relating to treatable traits in airway diseases; in particular, those traits that can predict exacerbations and approaches to management that aim to prevent exacerbations by using a treatable traits model of care. We propose this approach as a potentially useful model of care to both prevent and manage acute exacerbations.

Type 2 Inflammation and the Evolving Profile of Uncontrolled Persistent Asthma

The objective of this symposium was to provide an overview of Type 2 inflammation in asthma. The speakers covered the pathophysiology of Type 2 asthma, its heterogeneity, the associated economic burden, and methods for recognising Type 2 inflammation in severe asthma patients in clinical practice. Asthma is a heterogenous disease and multiple phenotypes are common among patients. Type 2 asthma is so named because it is associated with Type 2 inflammation and typically includes allergic asthma and moderate-to-severe eosinophilic asthma, Prof Canonica explained. By contrast, non-Type 2 asthma commonly has an older age of onset and is often associated with obesity and neutrophilic inflammation. Prof Diamant highlighted the scale and severity of uncontrolled persistent asthma. Globally, an estimated 420,000 people die of asthma every year, and many more have uncontrolled disease, putting them at risk of persistent airway inflammation and eventual lung decline. Patients may not recognise that their disease is uncontrolled, despite exacerbations and the impact of their asthma on daily activities. Prof Diamant described the impairments to health-related quality of life and the associated costs of uncontrolled asthma. Prof Dahlén outlined how new predictive biomarkers will be needed to identify the type of asthma an individual patient has. No single biomarker will provide sufficient information, and as such, in the future, profiles of many markers will need to be integrated to produce subgroup-specific profiles for use in personalised medicine. He described ongoing research into protein arrays and lipid mediators in urine, and how cluster analysis and pattern recognition, with the aid of artificial intelligence, will form the basis of future diagnostic tools. Prof Canonica explained that an understanding of the mechanisms of asthma is important in achieving better symptom control. IL-4 and IL-13 are key players in the pathobiology of uncontrolled persistent asthma (IL-4 in inflammation and IL-13 in airway remodelling), but their roles overlap. The heterogenous nature of Type 2 asthma can make it difficult to diagnose; therefore, focussing on a single biomarker is likely to leave some patients sub-optimally controlled.

Oxidative stress and macrophages: driving forces behind exacerbations of asthma and chronic obstructive pulmonary disease?

Oxidative stress is a common feature of obstructive airway diseases like asthma and chronic obstructive pulmonary disease (COPD). Lung macrophages are key innate immune cells that can generate oxidants and are known to display aberrant polarization patterns and defective phagocytic responses in these diseases. Whether these characteristics are linked in one way or another and whether they contribute to the onset and severity of exacerbations in asthma and COPD remain poorly understood. Insight into oxidative stress, macrophages, and their interactions may be important in fully understanding acute worsening of lung disease. This review therefore highlights the current state of the art regarding the role of oxidative stress and macrophages in exacerbations of asthma and COPD. It shows that oxidative stress can attenuate macrophage function, which may result in impaired responses toward exacerbating triggers and may contribute to exaggerated inflammation in the airways.

Omalizumab lowers asthma exacerbations, oral corticosteroid intake and blood eosinophils: Results of a 5-YEAR single-centre observational study

Omalizumab is a humanized monoclonal antibody which binds to human immunoglobulins E (IgE), thus preventing their interactions with both high affinity and low affinity IgE receptors. Therefore, omalizumab is currently recommended for add-on biological therapy of uncontrolled allergic asthma, mainly characterized by type 2 airway eosinophilic inflammation. Because omalizumab has been the first, and for a long time the only available monoclonal antibody for add-on treatment of type 2 asthma, some long-term studies have been published which provide a clear evidence of the therapeutic effectiveness of the anti-IgE pharmacological strategy. Within this context, the present single-centre observational study refers to 15 patients with severe allergic asthma, treated with omalizumab for at least 5 years at the Respiratory Unit of "Magna Græcia" University Hospital located in Catanzaro, Italy. In these asthmatic subjects we observed significant increases in asthma control test (ACT) score, with respect to baseline (14.60 ± 2.97), after 1 year (19.20 ± 2.98; p < 0.0001) and 5 years (21.67 ± 2.38; p < 0.0001) of add-on treatment with omalizumab. More importantly, omalizumab significantly lowered the number of annual asthma exacerbations (baseline: 3.66 ± 2.01) after 1 year (0.83 ± 1.14; p < 0.0001) and 5 years (0.63 ± 0.99; p < 0.0001), respectively. This excellent therapeutic outcome made it possible to drastically decrease the daily oral intake of prednisone (baseline: 22.50 ± 5.17 mg) after 1 year (1.83 ± 4.06 mg; p < 0.0001), as well as after 5 years (1.66 ± 3.61 mg; p < 0.0001). With regard to lung function, omalizumab significantly and persistently enhanced FEV₁ (baseline: 1636 ± 628.4 mL) after 1 year (2000 ± 679.7 mL; p < 0.05) and 5 years (1929 ± 564.8 mL; p < 0.05), respectively. Such relevant clinical and functional improvements were associated with reductions of blood eosinophil counts (baseline: 646.0 ± 458.9 cells/μl), already detectable after 1 year (512.7 ± 327.8 cells/μl; not significant), which reached the threshold of statistical significance after 5 years (326.0 ± 171.8 cells/μl; p < 0.05). Therefore, these real-life data referring to our single-centre observational investigation further corroborate the long-term therapeutic ability of omalizumab to improve several clinical, functional and haematological signatures of severe type 2 asthma.

Assessment of the long-term safety of mepolizumab and durability of clinical response in patients with severe eosinophilic asthma

BACKGROUND

Mepolizumab has demonstrated favorable safety and efficacy profiles in placebo-controlled trials of 12 months' duration or less; however, long-term data are lacking.

OBJECTIVE

We sought to evaluate the long-term safety and efficacy of mepolizumab in patients with severe eosinophilic asthma (SEA).

METHODS

COLUMBA (Open-label Long Term Extension Safety Study of Mepolizumab in Asthmatic Subjects, NCT01691859) was an open-label extension study in patients with SEA previously enrolled in DREAM (Dose Ranging Efficacy And Safety With Mepolizumab in Severe Asthma, NCT01000506). Patients received 100 mg of subcutaneous mepolizumab every 4 weeks plus standard of care until a protocol-defined stopping criterion was met. Safety end points included frequency of adverse events (AEs), serious AEs, and AEs of special interest. Efficacy end points included annualized exacerbation rates, changes from baseline in Asthma Control Questionnaire 5 scores, and blood eosinophil counts. Immunogenicity was also assessed.

RESULTS

Overall, 347 patients were enrolled for an average of 3.5 years (maximum, 4.5 years; total exposure, 1201 patient-years). On-treatment AEs were reported in 94% of patients (exposure-adjusted rate, 3688 events/1000 patient-years). The most frequently reported on-treatment AEs were respiratory tract infection, headache, bronchitis, and asthma worsening. Seventy-nine (23%) patients experienced 1 or more on-treatment serious AEs; there were 6 deaths, none of which were assessed as related to mepolizumab. For patients with 156 weeks or greater enrollment, the exacerbation rate was 0.74 events/y (weeks 0-156), a 56% reduction from the off-treatment period between DREAM and COLUMBA. For all patients, at the first postbaseline assessment, the mean Asthma Control Questionnaire 5 score was reduced by 0.47 points, and blood eosinophil counts were reduced by 78%, with similar improvements maintained throughout the study. The immunogenicity profile (8% anti-drug antibodies) was consistent with previous studies.

CONCLUSION

These data support the long-term safety and efficacy of mepolizumab in patients with SEA.

Heterogeneity and the origins of asthma

OBJECTIVE

To examine the roots of asthma across different ages, including atopy, the role of the microbiome and viral infections, and comorbidities and confounders, such as obesity, aspirin-exacerbated respiratory disease, neutrophilic asthma, cigarette smoking, and the possibility of an asthma-chronic obstructive pulmonary disease overlap syndrome.

DATA SOURCES

Data were taken from various scientific search engines, including PubMed and Science Direct databases.

STUDY SELECTIONS

Articles that reviewed information on the origins of asthma in persons of all ages, including different phenotypes and genotypes of asthma, were used.

RESULTS

Asthma is a common and complex disease whose origins are likely a combination of both genetic predisposition and environmental exposures. Factors such as the microbiome, other atopic disease, viral infections in young children, and other diagnoses, such as obesity or aspirin-exacerbated respiratory disease, are important to consider when creating a treatment plan for patients.

CONCLUSION

Asthma is a disease that is often diagnosed in childhood but can present at any age. There is debate in the field as to whether asthma is one disease or several different diseases that include airway inflammation as a key finding. There are risk factors for disease in the environment and through comorbidities that likely play significant roles in the origins of asthma, the development of symptoms, and the response to treatment. These factors are even more important as we look toward the future with the goal of personalized medicine.

Asthma

Asthma is the most common respiratory disorder in Canada. Despite significant improvement in the diagnosis and management of this disorder, the majority of Canadians with asthma remain poorly controlled. In most patients, however, control can be achieved through the use of avoidance measures and appropriate pharmacological interventions. Inhaled corticosteroids (ICS) represent the standard of care for the majority of patients. Combination ICS/long-acting beta₂-agonist inhalers are preferred for most adults who fail to achieve control with ICS therapy. Biologic therapies targeting immunoglobulin E or interleukin-5 are recent additions to the asthma treatment armamentarium and may be useful in select cases of difficult to control asthma. Allergen-specific immunotherapy represents a potentially disease-modifying therapy for many patients with asthma, but should only be prescribed by physicians with appropriate training in allergy. In addition to avoidance measures and pharmacotherapy, essential components of asthma management include: regular monitoring of asthma control using objective testing measures such as spirometry, whenever feasible; creation of written asthma action plans; assessing barriers to treatment and adherence to therapy; and reviewing inhaler device technique. This article provides a review of current literature and guidelines for the appropriate diagnosis and management of asthma in adults and children.

Real-life evaluation of the clinical, functional, and hematological effects of mepolizumab in patients with severe eosinophilic asthma: Results of a single-centre observational study

Mepolizumab is a humanized monoclonal antibody which targets interleukin-5 (IL-5) and is nowadays available in many countries for add-on biological therapy of severe eosinophilic asthma. Although the approval of mepolizumab use in clinical practice has been made possible by several successful pre-marketing controlled trials, so far only a very few studies have been performed in a real-life setting. Within such a context, our present observational investigation refers to 14 patients with refractory eosinophilic asthma, currently treated with mepolizumab at the Respiratory Unit of "Magna Græcia" University Hospital located in Catanzaro, Italy, whose anti-IL-5 treatment began between June 2017 and January 2018. These patients experienced a significant increase in asthma control test (ACT) score, that was evaluated at baseline (13.64 ± 3.00), as well as after 4 weeks (18.86 ± 3.15; p < 0.0001) and 24 weeks (20.07 ± 1.94; p < 0.0001) of add-on therapy with mepolizumab. This relevant improvement in symptom control was paralleled by a dramatic fall of blood eosinophil numbers, counted at baseline (647.1 ± 274.7 cells/μl), and at the 4th (147.8 ± 66.5 cells/μl; p < 0.0001) and 24th week (98.6 ± 40.3 cells/μl; p < 0.0001) after starting add-on treatment with mepolizumab. These changes were associated with significant and stable increases in FEV₁, which was recorded at baseline (1389 ± 454.3 mL), as well as after 4 weeks (1711 ± 482.3 mL; p < 0.001) and 24 weeks (1701 ± 456.0 mL; p < 0.01). Moreover, in comparison to the 6 months preceding the beginning of treatment with mepolizumab, after 24 weeks of anti-IL-5 therapy significant decreases were detected with regard to exacerbation numbers (from 3.64 ± 1.86 to 1.0 ± 0.78; p < 0.001) and oral intake of prednisone (from 24.11 ± 10.36 mg/day to 1.78 ± 3.82 mg/day). Therefore, these preliminary data referring to our single-centre observational study corroborate, in a real-life environment, the efficacy of mepolizumab for treatment of patients with exacerbation-prone, corticosteroid-refractory, severe eosinophilic asthma.

Dupilumab improves symptoms, quality of life, and productivity in uncontrolled persistent asthma

BACKGROUND

In a pivotal, phase 2b study (NCT01854047) in patients with uncontrolled persistent asthma, despite using medium-to-high-dose inhaled corticosteroids plus long-acting β2 agonists, dupilumab improved lung function, reduced severe exacerbations, and showed an acceptable safety profile.

OBJECTIVE

To assess the impact of dupilumab on asthma control, symptoms, quality of life (QoL), and productivity.

METHODS

Data are shown for the intention-to-treat population receiving dupilumab 200/300 mg every 2 weeks (doses being assessed in phase 3; NCT02414854), or placebo. Predefined analyses of total scores were conducted at week 24 for the 5-item Asthma Control Questionnaire (ACQ-5), patient-reported morning/evening (AM/PM) asthma symptoms, Asthma Quality of Life Questionnaire (AQLQ), and asthma-related productivity loss. Responder rate analyses for these measures, subgroup analyses by baseline characteristics, and asthma-related productivity loss analyses were conducted post hoc.

RESULTS

Data from 465 patients were analyzed (158 placebo; 307 dupilumab). Both dupilumab doses significantly improved scores through week 24 (all outcomes, overall population). The proportion of patients meeting or exceeding the minimal clinically important difference for the overall population were significantly greater vs placebo (P < .05) for ACQ-5 (range, 72.6%-76.7% vs 61.4%), for AM/PM asthma symptoms score (48.7%-54.1% vs 34.2% and 52.7%-53.5% vs 34.2%, respectively) and for AQLQ (64.0%-65.0% vs 51.3%). The effect of dupilumab was consistent across most subgroups. Productivity loss was significantly higher in placebo- vs dupilumab-treated patients (P < .0001).

CONCLUSION

Dupilumab produced significant, clinically meaningful improvements in asthma control, symptoms, QoL, and productivity.

REGISTRATION

ClinicalTrials.gov Identifier: NCT01854047.

Immunoproteasomes as a novel antiviral mechanism in rhinovirus-infected airways

Rhinovirus (RV) infection is involved in acute exacerbations of asthma and chronic obstructive pulmonary disease (COPD). RV primarily infects upper and lower airway epithelium. Immunoproteasomes (IP) are proteolytic machineries with multiple functions including the regulation of MHC class I antigen processing during viral infection. However, the role of IP in RV infection has not been explored. We sought to investigate the expression and function of IP during airway RV infection. Primary human tracheobronchial epithelial (HTBE) cells were cultured at air-liquid interface (ALI) and treated with RV16, RV1B, or interferon (IFN)-λ in the absence or presence of an IP inhibitor (ONX-0914). IP gene (i.e. LMP2) deficient mouse tracheal epithelial cells (mTECs) were cultured for the mechanistic studies. LMP2-deficient mouse model was used to define the in vivo role of IP in RV infection. IP subunits LMP2 and LMP7, antiviral genes MX1 and OAS1 and viral load were measured. Both RV16 and RV1B significantly increased the expression of LMP2 and LMP7 mRNA and proteins, and IFN-λ mRNA in HTBE cells. ONX-0914 down-regulated MX1 and OAS1, and increased RV16 load in HTBE cells. LMP2-deficient mTECs showed a significant increase in RV1B load compared with the wild-type (WT) cells. LMP2-deficient (compared with WT) mice increased viral load and neutrophils in bronchoalveolar lavage (BAL) fluid after 24 h of RV1B infection. Mechanistically, IFN-λ induction by RV infection contributed to LMP2 and LMP7 up-regulation in HTBE cells. Our data suggest that IP are induced during airway RV infection, which in turn may serve as an antiviral and anti-inflammatory mechanism.

Prevalence, characteristics and management of frequently exacerbating asthma patients: an observational study in Sweden (PACEHR)

The aim of the study was to investigate the prevalence, management and characteristics of asthma patients with frequent exacerbations.Data from asthma patients (aged ≥18 years) identified in primary care medical records were linked to Swedish national health registries. Exacerbations were defined as hospitalisations, emergency visits and/or collection of oral steroids. Frequent exacerbations were defined as two or more exacerbations per year during the 3-year observation period.Of 18 724 asthma patients, 81.49% had no exacerbations and 6.3% had frequent exacerbations in the year prior to the index date. Frequent exacerbations were observed yearly for 1.8% of the patients. Frequent exacerbators were older, more often females, and had increased eosinophil and neutrophil counts, lower lung function, and more comorbidities than patients without exacerbations. There was a slight increase in asthma medication claims and a slight decrease in physician visits compared with baseline, both in the group with and the group without frequent exacerbations.Patients with frequent exacerbations were characterised by greater age, female predominance, high eosinophil and neutrophil counts, and high prevalence of comorbidities. This study indicates that the Swedish healthcare system lacks efficiency to adjust treatment and management for this patient group. With new treatment options targeting severe asthma available, identification of these patients should be in focus to ensure reduction of exacerbations.

At-risk children with asthma (ARC): a systematic review

Introduction

Asthma attacks are responsible for considerable morbidity and may be fatal. We aimed to identify and weight risk factors for asthma attacks in children (5–12 years) in order to inform and prioritise care.

Methods

We systematically searched six databases (May 2016; updated with forward citations January 2017) with no language/date restrictions. Two reviewers independently selected studies for inclusion, assessed study quality and extracted data. Heterogeneity precluded meta-analysis. Weighting was undertaken by an Expert Panel who independently assessed each variable for degree of risk and confidence in the assessment (based on study quality and size, effect sizes, biological plausibility and consistency of results) and then achieved consensus by discussion. Assessments were finally presented, discussed and agreed at a multidisciplinary workshop.

Results

From 16 109 records, we included 68 papers (28 cohort; 4 case-control; 36 cross-sectional studies). Previous asthma attacks were associated with greatly increased risk of attack (ORs between 2.0 and 4.1). Persistent symptoms (ORs between 1.4 and 7.8) and poor access to care (ORs between 1.2 and 2.3) were associated with moderately/greatly increased risk. A moderately increased risk was associated with suboptimal drug regimen, comorbid atopic/allergic disease, African-American ethnicity (USA), poverty and vitamin D deficiency. Environmental tobacco smoke exposure, younger age, obesity and low parental education were associated with slightly increased risk.

Discussion

Assessment of the clinical and demographic features identified in this review may help clinicians to focus risk reduction management on the high-risk child. Population level factors may be used by health service planners and policymakers to target healthcare initiatives.

Trial registration number

CRD42016037464.

Identification of patterns of factors preceding severe or life-threatening asthma exacerbations in a nationwide study

BACKGROUND

Reducing near-fatal asthma exacerbations is a critical problem in asthma management.

OBJECTIVES

To determine patterns of factors preceding asthma exacerbations in a real-world setting.

METHODS

In a nationwide prospective study of 190 patients who had experienced near-fatal asthma exacerbation, cluster analysis was performed using asthma symptoms over the 2-week period before admission.

RESULTS

Three distinct clusters of symptoms were defined employing the self-reporting of a visual analogue scale. Cluster A (42.1%): rapid worsening within 7.4 hours from moderate attack to admission, young to middle-aged patients with low Body mass index and tendency to depression who had stopped anti-asthma medications, smoked, and hypersensitive to environmental triggers and furred pets. Cluster B (40.0%): fairly rapid worsening within 48 hours, mostly middle-aged and older, relatively good inhaled corticosteroid (ICS) or ICS/long-acting beta-agonist (LABA) compliance, and low perception of dyspnea. Cluster C (17.9%): slow worsening over 10 days before admission, high perception of dyspnea, smokers, and chronic daily mild-moderate symptoms. There were no differences in overuse of short-acting beta-agonists, baseline asthma severity, or outcomes after admission for patients in these 3 clusters.

CONCLUSION

To reduce severe or life-threatening asthma exacerbation, personalized asthma management plans should be considered for each cluster. Improvement of ICS and ICS/LABA compliance and cessation of smoking are important in cluster A. To compensate for low perception of dyspnea, asthma monitoring of peak expiratory flow rate and/or exhaled nitric oxide would be useful for patients in cluster B. Avoidance of environmental triggers, increase usual therapy, or new anti-type 2 response-targeted therapies should be considered for cluster C.

Type 2 Biomarkers and Prediction of Future Exacerbations and Lung Function Decline in Adult Asthma

BACKGROUND

Type 2 biomarkers that predict both likelihood of future severe exacerbations and response to mAb therapy in asthma would be useful clinically in identifying patients both at greater risk of hospitalization and most likely to benefit from mAb therapy.

OBJECTIVE

To describe the association between type 2 biomarkers, blood eosinophils, fractional exhaled nitric oxide (Feno), serum periostin, and serum IgE, and time to severe exacerbation in a broad asthma population.

METHODS

Participants from 2 adult asthma cohorts with baseline measurements of blood eosinophils, Feno, serum periostin, and serum IgE were reviewed after at least 12 months to obtain an exacerbation history, corroborated with general practitioner and hospital medical records. The association between baseline type 2 biomarkers and time to exacerbation was described by Cox proportional hazard ratios (HRs) using multivariate models.

RESULTS

A total of 212 participants were followed for a median (range) 3.8 (1.1-5.3) years; 67 of 212 (32%) had at least 1 severe exacerbation. The HRs (95% CI) of baseline type 2 biomarkers and time to exacerbation were as follows: blood eosinophils per 0.1 × 10⁹/L increase, 0.89 (0.76-1.05), P = .17; log Feno per 0.693 increase, 0.65 (0.52-0.81), P < .001; log serum periostin per 0.693 increase, 0.62 (0.35-1.09), P = .10; log serum IgE per 0.693 increase, 0.89 (0.80-1.00), P = .05.

CONCLUSIONS

The positive association between type 2 biomarkers and risk of severe exacerbations in populations with severe refractory asthma does not extend to mild and moderate asthma. Non-type 2 asthma may represent a phenotype associated with an increased risk of severe exacerbations in a broad asthma population.

Azithromycin augments rhinovirus-induced IFNβ via cytosolic MDA5 in experimental models of asthma exacerbation

Deficient production of anti-viral interferons (IFNs) may be involved in causing viral-induced asthma exacerbations. Hence, drugs inducing lung IFN production would be warranted. Azithromycin may reduce asthma exacerbations but its modus operandi is unknown. Here, we investigated if azithromycin induces IFNβ expression in vitro in rhinovirus-infected bronchial epithelial cells from asthmatic donors and in vivo in our allergic inflammation-based mouse model of viral stimulus-induced asthma exacerbations. Azithromycin dose-dependently augmented viral-induced IFNβ expression in asthmatic, but not in healthy bronchial epithelial cells. The effect negatively correlated with viral load. Knockdown of MDA5 and RIG-I by siRNA showed involvement of MDA5 but not RIG-I in azithromycin's IFN-inducing effects in vitro. In vivo azithromycin induced IFNβ protein, restoring a reduced lung IFN response exclusively in allergic exacerbating mice. This was associated with induction of interferon-stimulated genes and MDA5, but not RIG-I. We suggest that clinically relevant concentrations of azithromycin produce MDA5-dependent, anti-viral, IFN-inducing effects in bronchial epithelium distinctly from asthmatic donors. Similarly, azithromycin induced MDA5-associated IFN in virally stimulated lungs in vivo exclusively in allergic mice. Effects of azithromycin and MDA5-active drugs on viral-induced exacerbations deserve further research.

Asthma Exacerbations Associated with Lung Function Decline in Patients with Severe Eosinophilic Asthma

BACKGROUND

Limited data describe the association between the frequency of asthma exacerbations and the decline in lung function in severe asthma.

OBJECTIVE

To determine whether asthma exacerbations are associated with enhanced decline in lung function.

METHODS

Changes in lung function were analyzed retrospectively using data from the DREAM and MENSA studies of mepolizumab intervention in patients with severe asthma. Patients were either nonsmokers or former smokers. A linear regression model was used to analyze the relationship between the number of exacerbations and decline in FEV₁ across treatment groups.

RESULTS

In a combined post hoc analysis, 57% (n = 572) of patients had no exacerbations and experienced an improvement in postbronchodilator FEV₁ of 143 mL. In contrast, in patients who experienced 3 or more exacerbations, there was a decrease in postbronchodilator FEV₁ of 77 mL in the combined analysis. The linear modeling analysis estimated that for each exacerbation seen during the observational period, there was a decrease of 50 mL in FEV₁ (P < .001).

CONCLUSIONS

A direct relationship between the number of exacerbations in patients with severe eosinophilic asthma and decline in lung function was observed. Repeated exacerbations may be associated with accelerated loss of lung function.

Exacerbations in Adults with Asthma: A Systematic Review and External Validation of Prediction Models

BACKGROUND

Several prediction models assessing future risk of exacerbations in adult patients with asthma have been published. Applicability of these models is uncertain because their predictive performance has often not been assessed beyond the population in which they were derived.

OBJECTIVE

This study aimed to identify and critically appraise prediction models for asthma exacerbations and validate them in 2 clinically distinct populations.

METHODS

PubMed and EMBASE were searched to April 2017 for reports describing adult asthma populations in which multivariable models were constructed to predict exacerbations during any time frame. After critical appraisal, the models' predictive performances were assessed in a primary and a secondary care population for author-defined exacerbations and for American Thoracic Society/European Respiratory Society-defined severe exacerbations.

RESULTS

We found 12 reports from which 24 prediction models were evaluated. Three predictors (previous health care utilization, symptoms, and spirometry values) were retained in most models. Assessment was hampered by suboptimal methodology and reporting, and by differences in exacerbation outcomes. Discrimination (area under the receiver-operating characteristic curve [c-statistic]) of models for author-defined exacerbations was better in the primary care population (mean, 0.71) than in the secondary care population (mean, 0.60) and similar (0.65 and 0.62, respectively) for American Thoracic Society/European Respiratory Society-defined severe exacerbations. Model calibration was generally poor, but consistent between the 2 populations.

CONCLUSIONS

The preservation of 3 predictors in models derived from variable populations and the fairly consistent predictive properties of most models in 2 distinct validation populations suggest the feasibility of a generalizable model predicting severe exacerbations. Nevertheless, improvement of the models is warranted because predictive performances are below the desired level.

Predictors of accelerated decline in lung function in adult-onset asthma

Little is known about the prognosis of adults with new-onset asthma. Cross-sectional studies suggest that these patients may exhibit accelerated decline in forced expiratory volume in 1 s (FEV₁). However, risk factors for accelerated decline in lung function have not yet been identified.We aimed to identify these risk factors in a prospective 5-year follow-up study in 200 adults with newly diagnosed asthma. In the current study, clinical, functional and inflammatory parameters were assessed annually for 5 years. Linear mixed-effects models were used to identify predictors.Evaluable lung function sets of 141 patients were available. Median (interquartile range) change in post-bronchodilator FEV₁ was -17.5 (-54.2 to +22.4) mL per year. Accelerated decline in FEV₁ was defined by the lower quartile of decline (>54.2 mL per year). Nasal polyps, number of blood and sputum eosinophils, body mass index, and level of exhaled nitric oxide were univariably associated with decline in lung function. Only the latter two were independently associated. Using cut-off values to identify patients at highest risk showed accelerated decline in FEV₁ in all patients with combined exhaled nitric oxide fraction (F_eNO) ≥57 ppb and body mass index (BMI) ≤23 kg·m^-2We conclude that adults with new-onset asthma with both high levels of exhaled nitric oxide and low BMI are at risk of accelerated decline in lung function.

Asthma Exacerbations: Pathogenesis, Prevention, and Treatment

Guideline-based management of asthma focuses on disease severity and choosing the appropriate medical therapy to control symptoms and reduce the risk of exacerbations. However, irrespective of asthma severity and often despite optimal medical therapy, patients may experience acute exacerbations of symptoms and a loss of disease control. Asthma exacerbations are most commonly triggered by viral respiratory infections, particularly with human rhinovirus. Given the importance of these events to asthma morbidity and health care costs, we will review common inciting factors for asthma exacerbations and approaches to prevent and treat these events.

Persistent activation of interlinked type 2 airway epithelial gene networks in sputum-derived cells from aeroallergen-sensitized symptomatic asthmatics

Atopic asthma is a persistent disease characterized by intermittent wheeze and progressive loss of lung function. The disease is thought to be driven primarily by chronic aeroallergen-induced type 2-associated inflammation. However, the vast majority of atopics do not develop asthma despite ongoing aeroallergen exposure, suggesting additional mechanisms operate in conjunction with type 2 immunity to drive asthma pathogenesis. We employed RNA-Seq profiling of sputum-derived cells to identify gene networks operative at baseline in house dust mite-sensitized (HDM^S) subjects with/without wheezing history that are characteristic of the ongoing asthmatic state. The expression of type 2 effectors (IL-5, IL-13) was equivalent in both cohorts of subjects. However, in HDM^S-wheezers they were associated with upregulation of two coexpression modules comprising multiple type 2- and epithelial-associated genes. The first module was interlinked by the hubs EGFR, ERBB2, CDH1 and IL-13. The second module was associated with CDHR3 and mucociliary clearance genes. Our findings provide new insight into the molecular mechanisms operative at baseline in the airway mucosa in atopic asthmatics undergoing natural aeroallergen exposure, and suggest that susceptibility to asthma amongst these subjects involves complex interactions between type 2- and epithelial-associated gene networks, which are not operative in equivalently sensitized/exposed atopic non-asthmatics.

Pathophysiology of severe asthma: We've only just started

Severe asthma is defined by the high treatment requirements to partly or fully control the clinical manifestations of disease. It remains a problem worldwide with a large burden for individuals and health services. The key to improving targeted treatments, reducing disease burden and improving patient outcomes is a better understanding of the pathophysiology and mechanisms of severe disease. The heterogeneity, complexity and difficulties in undertaking clinical studies in severe asthma remain challenges to achieving better understanding and better outcomes. In this review, we focus on the structural, mechanical and inflammatory abnormalities that are relevant in severe asthma.

Identification of IFN-γ and IL-27 as Critical Regulators of Respiratory Syncytial Virus-Induced Exacerbation of Allergic Airways Disease in a Mouse Model

Respiratory syncytial virus (RSV) infection induces asthma exacerbations, which leads to worsening of clinical symptoms and may result in a sustained decline in lung function. Exacerbations are the main cause of morbidity and mortality associated with asthma, and significantly contribute to asthma-associated healthcare costs. Although glucocorticoids are used to manage exacerbations, some patients respond to them poorly. The underlying mechanisms associated with steroid-resistant exacerbations remain largely unknown. We have previously established a mouse model of RSV-induced exacerbation of allergic airways disease, which mimics hallmark clinical features of asthma. In this study, we have identified key roles for macrophage IFN-γ and IL-27 in the regulation of RSV-induced exacerbation of allergic airways disease. Production of IFN-γ and IL-27 was steroid-resistant, and neutralization of IFN-γ or IL-27 significantly suppressed RSV-induced steroid-resistant airway hyperresponsiveness and airway inflammation. We have previously implicated activation of pulmonary macrophage by TNF-α and/or MCP-1 in the mechanisms of RSV-induced exacerbation. Stimulation of pulmonary macrophages with TNF-α and/or MCP-1 induced expression of both IFN-γ and IL-27. Our findings highlight critical roles for IFN-γ and IL-27, downstream of TNF-α and MCP-1, in the mechanism of RSV-induced exacerbation. Thus, targeting the pathways that these factors activate may be a potential therapeutic approach for virus-induced asthma exacerbations.

Detection of pathogens by real-time PCR in adult patients with acute exacerbation of bronchial asthma

BACKGROUND

Respiratory tract infection is a major cause of acute exacerbation of bronchial asthma (AEBA). Although recent findings suggest that common bacteria are causally associated with AEBA, a comprehensive epidemiologic analysis of infectious pathogens including common/atypical bacteria and viruses in AEBA has not been performed. Accordingly, we attempted to detect pathogens during AEBA by using real-time polymerase chain reaction (PCR) in comparison to conventional methods.

METHODS

We prospectively enroled adult patients with AEBA from August 2012 to March 2014. Infectious pathogens collected in nasopharyngeal swab and sputum samples were examined in each patient by conventional methods and real-time PCR, which can detect 6 bacterial and 11 viral pathogens. The causal association of these pathogens with AEBA severity and their frequency of monthly distribution were also examined.

RESULTS

Among the 64 enroled patients, infectious pathogens were detected in 49 patients (76.6%) using real-time PCR and in 14 patients (21.9%) using conventional methods (p < 0.001). Real-time PCR detected bacteria in 29 patients (45.3%) and respiratory viruses in 28 patients (43.8%). Haemophilus influenzae was the most frequently detected microorganism (26.6%), followed by rhinovirus (15.6%). Influenza virus was the significant pathogen associated with severe AEBA. Moreover, AEBA occurred most frequently during November to January.

CONCLUSIONS

Real-time PCR was more useful than conventional methods to detect infectious pathogens in patients with AEBA. Accurate detection of pathogens with real-time PCR may enable the selection of appropriate anti-bacterial/viral agents as a part of the treatment for AEBA.

Respiratory Syncytial Virus Exacerbates OVA-mediated asthma in mice through C5a-C5aR regulating CD4+T cells Immune Responses

Asthma exacerbation could be induced by respiratory syncytial virus (RSV), and the underlying pathogenic mechanism is related to complement activation. Although complement might regulate CD4⁺T cells immune responses in asthma model, this regulation existed in RSV-induced asthma model remains incompletely characterrized. In this study, we assessed the contribution of C5a-C5aR to CD4⁺T cell immune responses in RSV-infected asthma mice. Female BALB/C mice were sensitized and challenged with ovalbumin (OVA) while treated with RSV infection and C5a receptor antagonist (C5aRA) during challenge period. RSV enhanced lung damage, airway hyperresponsiveness, and C5aR expressions in asthma mice, while C5aRA alleviated these pathologic changes. The percentages of Th1, Th2 and Th17 cells were increased, while the percentage of Treg cells was decreased in RSV-infected asthma mice compared with asthma mice. IFN-γ, IL-4, IL-10 and IL-17A levels have similar trend with Th1, Th2, Th17 and Treg cells. Notably, above changes of CD4⁺T cells and their related cytokines were reversed by C5aRA. Together, the data indicates that RSV infection could apparently increase C5a and C5aR expression in the pathogenesis of RSV-infected asthma mice, meanwhile C5aRA prevents some of the CD4⁺T cells immune changes that are induced by RSV.

The clinical role of fractional exhaled nitric oxide in asthma control

BACKGROUND

The potential role and characteristics of fractional exhaled nitric oxide (FeNO) remain unclear in the treatment of asthma.

OBJECTIVE

To explore the clinical role of FeNO in asthmatic treatment.

METHODS

We evaluated whether the mean or change of FeNO levels in the treatment period is associated with other conventional control parameters and predicted some clinical outcomes of asthma. We retrospectively analyzed the mean and percentage change of FeNO levels in the first 5 measurements at our hospital.

RESULTS

The study found a significantly strong correlation between FeNO level at diagnosis and the largest changes of FeNO values from diagnosis. No significant correlations were observed between FeNO levels and other parameters (Asthma Control Test [ACT] score or forced expiratory volume in one second [FEV₁]) in mean and percentage change of values under treatment of asthma; however, significant positive correlations were found between ACT scores and FEV₁. The mean FeNO level revealed a significant negative correlation with an annual change in FEV₁ in individuals with asthma who were followed up for more than 2 years. Both the mean ACT score and percent predicted FEV₁ revealed a significant negative correlation with occasional use of systemic corticosteroids.

CONCLUSION

During conventional treatment of asthma, the largest changes of FeNO values from diagnosis were strongly correlated with FeNO levels at diagnosis. As for the unlikely conventional parameters, no significant associations were observed between FeNO levels and deterioration of asthma during the treatment periods. An elevated mean FeNO level may be a marker of decreased lung function in individuals with asthma.