Comorbidities and elevated IL-6 associate with negative outcome in adult-onset asthma

Occupational exposures and asthma-COPD overlap in a clinical cohort of adult-onset asthma

Occupational exposure to vapours, gases, dusts or fumes (VGDF) increases the prevalence of asthma-COPD overlap (ACO) in adult-onset asthma. VGDF exposure is independently associated with ACO and an additive effect with smoking is proposed. http://bit.ly/2LiMiXW.

Evidence for similarity in symptoms and mechanism: The extra-pulmonary symptoms of severe asthma and the polysymptomatic presentation of fibromyalgia

BACKGROUND

Asthma is a disease of the lung and a systemic disease. Functional disorders are associated with multiple systemic abnormalities that have been explained by complexity models. The aim was to test the similarity in type and aetiology between the extra-pulmonary symptoms of severe asthma and the symptoms of fibromyalgia.

METHODS

One Hundred patients recruited from a specialist severe asthma clinic and 1751 people reporting different functional disorder diagnoses recruited via the internet completed the same 60-item questionnaire. Symptom patterns were compared between groups using a new measure, the symptom pattern similarity index where 0 = no relationship, 1 = identical patterns between groups.

RESULTS

Severe asthma patients report numerous extra-pulmonary symptoms. The similarity index between the symptom pattern of the asthma patients with other groups was irritable bowel syndrome = 0.54, chronic fatigue syndrome = 0.69, and fibromyalgia = 0.75. The index between fibromyalgia and asthma patients with the most and least frequent extra-pulmonary symptoms was 0.81 and 0.55 respectively.

CONCLUSIONS

Patients with severe asthma have numerous extra-pulmonary symptoms similar in type and pattern to the symptoms of fibromyalgia. The similarity of the symptom pattern between asthma and fibromyalgia increases as the number of extra-pulmonary symptoms increases as predicted by network theory and previously shown to be the case with other functional disorders. These findings support the hypothesis that functional disorders and extra-pulmonary asthma symptoms have a common complexity or network aetiology. Evidence based behavioural interventions for fibromyalgia may be helpful for patients with severe asthma reporting extra-pulmonary symptoms.

Effects of interleukin-6 receptor blockade on allergen-induced airway responses in mild asthmatics

Background

Interleukin (IL)-6 signalling has been implicated in allergic asthma by animal, genetic association and clinical studies. In this study, we tested the hypothesis that tocilizumab (TCZ), a human monoclonal antibody that blocks IL-6 signalling, can prevent the development of allergen-induced bronchoconstriction in humans.

Methods

We performed a randomised, double-blind, placebo-controlled study, with eligible participants completing two allergen inhalation challenge tests, conducted before and after treatment with a single dose of TCZ or placebo. The primary efficacy endpoint was the magnitude of the late asthmatic response recorded between 3 and 7 after allergen challenge. The secondary efficacy endpoint was the early asthmatic response, measured 20 min to 2 h after allergen challenge.

Results

A total of 66 patients enrolled between September 2014 and August 2017, when the trial was stopped for futility based on results from an interim analysis. Eleven patients fulfilled all eligibility criteria assessed at baseline and were subsequently randomised to the TCZ (n = 6) or placebo (n = 5) groups. Both the primary and secondary efficacy endpoints were not significantly different between the two groups. Five patients reported adverse events (AEs), three in the TCZ group (11 AEs) and two in the placebo group (four AEs). Only one AE was TCZ-related (mild neutropenia), and there were no serious AEs. Significant treatment effects were observed for serum levels of C-reactive protein, IL-6 and soluble IL-6R levels.

Conclusion

In a small proof-of-concept clinical trial, we found no evidence that a single dose of tocilizumab was able to prevent allergen-induced bronchoconstriction. (Trial registered in the Australian New Zealand Clinical Trials Registry, number ACTRN12614000123640).

Epithelial growth factor receptor tyrosine kinase inhibitors alleviate house dust mite allergen Der p2-induced IL-6 and IL-8

Steroid-insensitive asthma-related airway inflammation is associated with the expression of epidermal growth factor receptor (EGFR) tyrosine kinase in asthmatic bronchial epithelium. Proinflammatory cytokines IL-6 and IL-8 are related to steroid-insensitive asthma. It is currently unknown how EGFR-tyrosine kinase inhibitors (EGFR-TKIs) affects house dust mite (HDM)-induced asthma in terms of inflammatory cytokines related to steroid-resistant asthma and further signaling pathway. Cytokine expressions and EGFR signaling pathway were performed by ELISA, reverse transcriptase PCR, real-time PCR, and Western blot in cell-line models. AMP-activated protein kinase (AMPK) pathway-related inhibitors were applied to confirm the association between EGFR-TKI and AMPK pathway. HDM induced IL-6 and IL-8 in a dose-dependent manner. Both Erlotinib (Tarceva) and Osimertinib (AZD-9291) reduced the levels of HDM-stimulated IL-6 and IL-8 levels in BEAS-2B cells. AZD-9291 was more effective than Erlotinib in inhibiting phospho-EGFR, and downstream phosphatidylinositol-3-kinase/protein kinase B (PI3K/AKT) and phopho-signal transducer and activator of transcription 3 (p-STAT3) pathway signaling. In addition, AMPK pathway-related inhibitor, Calcium-/calmodulin-dependent protein kinase kinase β (CaMKKβ) inhibitor, down-regulated IL-8, but EGFR-TKI had no effect on AMPK pathway. Our findings highlight EGFR-TKIs, Tarceva, and AZD-9291, attenuate HDM-induced inflammatory IL-6 and IL-8 cytokines via EGFR signaling axis pathway, but not AMPK signaling pathway.

Non-redundant Functions of IL-6 Produced by Macrophages and Dendritic Cells in Allergic Airway Inflammation

Asthma is a common inflammatory disease of the airway caused by a combination of genetic and environmental factors and characterized by airflow obstruction, wheezing, eosinophilia, and neutrophilia of lungs and sputum. Similar to other proinflammatory cytokines, IL-6 is elevated in asthma and plays an active role in this disease. However, the exact molecular mechanism of IL-6 involvement in the pathogenesis of asthma remains largely unknown and the major cellular source of pathogenic IL-6 has not been defined. In the present study, we used conditional gene targeting to demonstrate that macrophages and dendritic cells are the critical sources of pathogenic IL-6 in acute HDM-induced asthma in mice. Complete genetic inactivation of IL-6 ameliorated the disease with significant decrease in eosinophilia in the lungs. Specific ablation of IL-6 in macrophages reduced key indicators of type 2 allergic inflammation, including eosinophil and Th2 cell accumulation in the lungs, production of IgE and expression of asthma-associated inflammatory mediators. In contrast, mice with deficiency of IL-6 in dendritic cells demonstrated attenuated neutrophilic, but regular eosinophilic response in HDM-induced asthma. Taken together, our results indicate that IL-6 plays a pathogenic role in the HDM-induced asthma model and that lung macrophages and dendritic cells are the predominant sources of pathogenic IL-6 but contribute differently to the disease.

Daily physical activity and lung function decline in adult-onset asthma: a 12-year follow-up study

Background: There is a lack of knowledge on the association between daily physical activity and lung function in patients with asthma.

Objective: This study aims to examine the association between daily physical activity and asthma control, lung function, and lung function decline in patients with adult-onset asthma.

Design: This study is part of Seinäjoki Adult Asthma Study (SAAS), where 201 patients were followed for 12 years after asthma diagnosis. Daily physical activity was assessed at follow-up by a structured questionnaire and used to classify the population into subgroups of low (≤240 min) or high (>240 min) physical activity. Three spirometry evaluation points were used: 1. diagnosis, 2. the maximum lung function during the first 2.5 years after diagnosis (Max_0-2.5), 3. follow-up at 12 years.

Results: High physical activity group had slower annual FEV₁ (p<0.001) and FVC (p<0.018) decline. Additionally, the high physical activity group had higher FEV₁ values at follow-up, and higher FEV₁/FVC ratios at follow-up and diagnosis. There was no difference in BMI, smoking, medication, or frequency of physical exercise between high and low physical activity groups. Differences remained significant after adjustments for possible confounding factors.

Conclusion: This is the first demonstration of an association between long-term FEV₁ decline and daily physical activity in clinical asthma. Low physical activity is independently associated with faster decline in lung function. Daily physical activity should be recommended in treatment guidelines in asthma.

Comparative Immunomodulatory Activity of Nigella sativa L. Preparations on Proinflammatory Mediators: A Focus on Asthma

Introduction: A range of traditional and commercial preparations of NS is frequently used in the treatment of several inflammatory diseases. Often, these preparations have poor preclinical characterization that may lead to variable pharmacological effects. Objective: To assess the in vitro effects of different chemically defined preparations of NS on some asthma-related mediators of inflammation. Methods: Different NS preparations were obtained by either seed extraction with a spectrum of solvents ranging from lipophilic to hydrophilic, or commercial products were collected. The TQ concentration of NS was analyzed by HPLC. Immunomodulatory activity was assessed by the release of mediators (IL-2, IL-6, PGE2) in primary human T-lymphocytes, monocytes, and A549 human lung epithelial cells. Results: Ten distinct NS preparations showed variability in TQ concentration, being highest in the oily preparations extract-7 (2.4% w/w), followed by extract-10 (0.7%w/w). Similarly, the release of mediators was varied, being greatest in extract-7 and 10 via significantly (<0.05) suppressing IL-2, IL-6, and PGE2 in T-lymphocytes as well as IL-6 and PGE2 in monocytes. Also, PGE2 release in A549 cells was significantly enhanced by both extracts. Conclusion: The TQ concentration and in vitro activity were variable among the different NS preparations. TQ-rich oily NS preparations produced potent favorable immunomodulation in asthma inflammation and can be used in future studies.

Systemic inflammatory markers in relation to lung function in NHANES. 2007-2010

BACKGROUND

Low-grade systemic inflammation, mainly assessed by C-reactive protein (CRP), has been associated with impaired lung function. Few studies have studied if CRP, blood eosinophils, and blood neutrophils offer additive information in relation to lung function.

OBJECTIVES

To analyse associations between lung function and CRP, blood eosinophils, and blood neutrophils, with special regard to additive information of combining the inflammatory markers.

METHODS

Cross-sectional study on 7753 participants, 20-80 years of age, in the National Health and Nutrition Examination Survey. Gender-based tertiles for CRP, blood eosinophils, and blood neutrophils were analysed in relation to the following lung function parameters: forced expiratory volume in 1 s (FEV₁% predicted), forced vital capacity (FVC % predicted), and FEV₁/FVC ratio.

RESULTS

CRP, blood eosinophils, and blood neutrophils levels were inversely related to FEV₁ and FVC. Only blood eosinophils and blood neutrophils were inversely related to FEV₁/FVC ratio. Further, lower lung function was found with increased number of elevated inflammatory markers in the highest tertile (one, two or three vs. non elevated) for FEV₁ (β-coeff., -2.20, -4.43, and -6.43, p < 0.001) and FVC (β-coeff., -1.70, -3.15 and -5.33, p < 0.001), respectively.

CONCLUSIONS & CLINICAL RELEVANCE

CRP, blood eosinophils, and blood neutrophils offer independent and additive information in relation to lower FEV₁ and FVC in the general population. This indicates that a combination of biomarkers yields more information than the biomarkers assessed individually.

Prevalence of Patients Eligible for Anti-IL-5 Treatment in a Cohort of Adult-Onset Asthma

BACKGROUND

Antibodies against the IL-5 pathway have been developed for the treatment of late-onset eosinophilic corticosteroid-resistant asthma. However, the prevalence of severe asthma and the proportion of patients who could benefit from such treatment among the general population of asthmatics remain unknown.

OBJECTIVE

To evaluate the prevalence and characteristics of patients eligible to anti-IL-5 treatment and severe asthma in an unselected cohort of adult-onset asthma.

METHODS

Seinäjoki Adult Asthma Study is a 12-year follow-up study of patients with new-onset adult asthma (n = 203). Prevalence was estimated based on information collected at 12-year follow-up visit. Health care use was collected from the whole 12-year follow-up period.

RESULTS

The prevalence of anti-IL-5-treatable patients was 2%, when the following criteria were used: daily use of medium-to-high inhaled corticosteroid (ICS) dose and long-acting β₂-agonist, ≥2 exacerbations/previous year and blood eosinophil count ≥300 cells/μL or fraction of exhaled nitric oxide ≥ 50 ppb. The prevalence of severe asthma, as defined according to European Respiratory Society/American Thoracic Society, was 5.9%, and only 1 patient met criteria for both groups. When compared with anti-IL-5 eligible patients, severe asthmatics were more often current smokers at diagnosis, obese, used higher ICS dose, and had higher blood neutrophils 12 years after diagnosis. Both groups differed from nonsevere asthma by a higher number of all and unplanned respiratory-related visits to health care. Severe asthmatics showed the highest number of hospitalizations.

CONCLUSIONS

In a cohort of unselected consecutive patients with adult-onset asthma, 5.9% fulfilled criteria for severe asthma and 2% qualified for anti-IL-5 treatment. Both groups represent a high burden to health care and specifically targeted treatment could lead to lower use of health care at long term.

Late-onset asthma: current perspectives

Because the pathophysiology of asthma has diverse characteristics, to manage the disease effectively, it is important for clinicians to distinguish among the clinical phenotypes. Among them, adult-onset asthma, that is, late-onset asthma (LOA), is increasing because of the aging of the population. The phenotype of LOA is largely divided into two types according to the presence or absence of eosinophilic inflammation, T-helper (Th)2- and non-Th2-associated LOA. Especially in Th2 LOA related to rhinosinusitis, as pulmonary function at onset is poor and asthma exacerbations occur frequently, it is important to detect this phenotype in the early phase by using a biomarker of Th2-type inflammation such as fractional exhaled nitric oxide (FENO). As non-Th2-LOA is often resistant to corticosteroids, this phenotype often requires another treatment strategy such as macrolide, diet, or smoking cessation. We often struggle with the management of LOA patients due to a lack of evidence; therefore, the elucidation of the mechanism of LOA contributes to increased efficiency of diagnosis and treatment of LOA. Age-related immune system and structural changes are thought to be associated with the pathophysiology of LOA. In the former case, changes in inflammatory cell function such as variations in the innate immune response and acquisition of autoimmunity or upregulation of oxidative stress are thought to be involved in the mechanism. Meanwhile, the latter can also become triggers or exacerbating factors of LOA via enhancement of airway hyperresponsiveness, decline in lung function, increased air trapping, and reduction in chest wall compliance. Therefore, appropriate individualized management in LOA may be possible through precisely assessing the pathophysiology based on age-related functional changes, including the immune and structural system.

Bronchiectasis and other chronic lung diseases in adolescents living with HIV

PURPOSE OF REVIEW

The incidence of pulmonary infections has declined dramatically with improved access to antiretroviral therapy (ART) and cotrimoxazole prophylaxis, but chronic lung disease (CLD) is an increasingly recognized but poorly understood complication in adolescents with perinatally acquired HIV.

RECENT FINDINGS

There is a high prevalence of chronic respiratory symptoms, abnormal spirometry and chest radiographic abnormalities among HIV-infected adolescents in sub-Saharan Africa, wherein 90% of the world's HIV-infected children live. The incidence of lymphocytic interstitial pneumonitis, the most common cause of CLD in the pre-ART era, has declined with increased ART access. Small airways disease, particularly constrictive obliterative bronchiolitis and bronchiectasis, are emerging as leading causes of CLD among HIV-infected adolescents in low-income and middle-income countries. Asthma may be more common in high-income settings. Likely risk factors for CLD include recurrent pulmonary infections, air pollution, HIV-related immune dysfunction, and untreated HIV infection, particularly during critical stages of lung development.

SUMMARY

Globally, the importance of HIV-associated CLD as a cause of morbidity and mortality is increasing, especially as survival has improved dramatically with ART and growing numbers of children living with HIV enter adolescence. Further research is urgently needed to elucidate the natural history and pathogenesis of CLD, and to determine optimal screening, diagnostic and treatment strategies.

Differences between asthma-COPD overlap syndrome and adult-onset asthma

Differences between asthma-COPD overlap syndrome (ACOS) and adult-onset asthma are poorly understood. This study aimed to evaluate these differences in a clinical cohort of patients with adult-onset asthma, as a part of the Seinäjoki Adult Asthma Study (SAAS).188 patients were diagnosed with adult-onset asthma and re-evaluated 12 years after diagnosis. They were divided into three groups based on smoking history and post bronchodilator spirometry values: 1) never- and ex-smokers with <10 smoked pack-years; 2) non-obstructive (forced expiratory volume in 1 s (FEV₁)/forced vital capacity (FVC) ≥0.7) patients with ≥10 pack-years; and 3) ACOS patients with ≥10 pack-years and FEV₁/FVC <0.7.ACOS patients had lower diffusing capacity (D_LCO/V_A 86% predicted versus 98 or 96% predicted; p<0.001), higher blood neutrophil levels (4.50 versus 3.60 or 3.85×10⁹ L^-1; p=0.008), and higher IL-6 levels (2.88 versus 1.52 or 2.10 pg·mL^-1, p<0.001) as compared to never- and ex-smokers with <10 pack-years, or non-obstructive patients with ≥10 pack-years smoking history, respectively. ACOS patients also showed reduced lung function, higher remaining bronchial reversibility and a higher number of comorbidities.This study shows distinct differences in diffusing capacity, blood neutrophil and IL-6 levels, bronchial reversibility, lung function and comorbidities between ACOS and adult-onset asthma. The present findings should be considered in the comprehensive assessment of adult asthma patients.

Asthma and smoking-induced airway disease without spirometric COPD

Due to the high prevalence rates of cigarette smoking and asthma, current and ex-smokers frequently develop chronic airway disease without spirometric evidence of chronic obstructive pulmonary disease (COPD), either alone or associated with asthma. This review considers the classification, clinical outcomes, inflammatory and imaging variables, phenotypes, and management of current and ex-smokers with airway disease without COPD, focusing on overlaps in those with and without asthma. These individuals have more respiratory symptoms, worse quality of life, increased exacerbation rates, reduced lung function and more comorbidities than never-smokers with asthma or healthy never-smokers. As well as clinical features, airway inflammatory and structural changes in smoking-induced airway disease without COPD overlap with those found in smokers with asthma. Cigarette smoking is associated with worse clinical outcomes in some phenotypes of asthma. Management involves public health measures to control exposure to tobacco smoke, personal advice on smoking cessation and the use of appropriate targeted therapies, although evidence is limited on their effectiveness. Understanding the mechanisms, natural history and management of current and ex-smokers with asthma and smoking-induced airway disease without COPD is a priority for future research.

Cluster Analysis on Longitudinal Data of Patients with Adult-Onset Asthma

BACKGROUND

Previous cluster analyses on asthma are based on cross-sectional data.

OBJECTIVE

To identify phenotypes of adult-onset asthma by using data from baseline (diagnostic) and 12-year follow-up visits.

METHODS

The Seinäjoki Adult Asthma Study is a 12-year follow-up study of patients with new-onset adult asthma. K-means cluster analysis was performed by using variables from baseline and follow-up visits on 171 patients to identify phenotypes.

RESULTS

Five clusters were identified. Patients in cluster 1 (n = 38) were predominantly nonatopic males with moderate smoking history at baseline. At follow-up, 40% of these patients had developed persistent obstruction but the number of patients with uncontrolled asthma (5%) and rhinitis (10%) was the lowest. Cluster 2 (n = 19) was characterized by older men with heavy smoking history, poor lung function, and persistent obstruction at baseline. At follow-up, these patients were mostly uncontrolled (84%) despite daily use of inhaled corticosteroid (ICS) with add-on therapy. Cluster 3 (n = 50) consisted mostly of nonsmoking females with good lung function at diagnosis/follow-up and well-controlled/partially controlled asthma at follow-up. Cluster 4 (n = 25) had obese and symptomatic patients at baseline/follow-up. At follow-up, these patients had several comorbidities (40% psychiatric disease) and were treated daily with ICS and add-on therapy. Patients in cluster 5 (n = 39) were mostly atopic and had the earliest onset of asthma, the highest blood eosinophils, and FEV₁ reversibility at diagnosis. At follow-up, these patients used the lowest ICS dose but 56% were well controlled.

CONCLUSIONS

Results can be used to predict outcomes of patients with adult-onset asthma and to aid in development of personalized therapy (NCT02733016 at ClinicalTrials.gov).

Severe and non-severe asthma in the community: A large electronic database analysis

BACKGROUND

A large electronic database analysis was conducted in a community of 351,799 people, ages 20-70 years to determine the prevalence and clinical characteristics of severe asthma, according to 2014 international guidelines and healthcare utilization.

METHODS

Severe asthmatics were grouped into controlled severe-asthma and uncontrolled severe-asthma and additional subgroups of uncontrolled severe asthma on the basis of medications dispensed. Non-asthmatic population at the same ages served as controls.

RESULTS

A total of 19,991 (5.68%) were diagnosed as asthmatic, of which 4.65% had severe asthma. Of these, one-third was uncontrolled severe-asthma. Controlled severe-asthma group was similar to non-severe asthma and non-asthmatics in the rate of emergency room visits (21.5%, 22%, and 20%, respectively) and to all cause hospitalizations (7.4%, 7.4%, and 6.4%, respectively). Uncontrolled severe-asthmatics had significantly more hospitalizations (RR = 2.9) than controlled severe-asthmatics. Only 19.2% of uncontrolled-severe asthmatics had IgE testing and 3.6% were dispensed omalizumab.

CONCLUSIONS

The prevalence of severe asthma is slightly less than 5% of all asthmatics. Controlling severe asthma is crucial to reducing healthcare utilization. A simple electronic database analysis, based on dispensed medications, can help healthcare providers identify subgroups of uncontrolled severe asthmatics that require focused efforts.

CLINICAL TRIAL REGISTRATION

NCT01961258. Ethics Committee approval: 032/2013C.

A 12-year prognosis of adult-onset asthma: Seinäjoki Adult Asthma Study

RATIONALE

Long-term prognosis of adult-onset asthma is poorly known.

OBJECTIVE

To evaluate 12-year prognosis of adult-onset asthma and the factors associated with disease prognosis.

METHODS

Seinäjoki Adult-onset Asthma Study (SAAS) is a 12-year real-life single-center follow-up study of new-onset asthma diagnosed at adult age and treated in primary and specialized care. Remission was defined by no symptoms and no asthma medication use for 6 months. Asthma control was evaluated according to Global Initiative for Asthma 2010. Factors associated with current asthma control were analyzed by multinomial multivariate logistic regression.

MAIN RESULTS

A total of 203 patients (79% of the baseline population) were followed for 12 years. Remission occurred in 6 (3%) patients. In 34% asthma was controlled, in 36% it was partially controlled and in 30% uncontrolled. Uncontrolled asthma was predicted by elevated body-mass index at baseline, smoking (pack-years) and current allergic or persistent rhinitis. Elevated blood eosinophils and good lung function (FEV1) at baseline protected from uncontrolled asthma. In contrast, gender, age at the onset or baseline symptoms (Airways Questionnaire 20) were not significant predictors of uncontrolled disease.

CONCLUSIONS

During a 12-year follow-up, remission of adult-onset asthma was rare occurring in only 3% of patients. The majority of patients (66%) presented either with uncontrolled or partially controlled asthma. This study is registered at ClinicalTrials.gov with identifier number NCT02733016.