Persistent airflow obstruction in patients with asthma: Characteristics of a distinct clinical phenotype

Serum Galectin-10: A biomarker for persistent airflow limitation in adult asthmatics

Background

Inhaled corticosteroids (ICS) are primary anti-inflammatory medications to control eosinophilic airway inflammation, and prevent asthma exacerbation. However, persistent airflow limitation (PAL) presents in some asthmatics even on ICS treatment, leading to lung function decline. Thus, we evaluated clinical associations of serum galectin-10 (Gal10) and galectin-3 (Gal3) levels in adult asthmatics who had maintained anti-asthma medication.

Methods

Sixty-seven asthmatics and 78 healthy controls (HCs) were recruited. Serum Gal10 and Gal3 levels were measured by enzyme-linked immunosorbent assay, and their clinical relevance with inflammatory and lung function parameters was evaluated. Spirometry was performed to assess PAL and small airway dysfunction (SAD). Airway epithelial cells were cocultured with eosinophils/neutrophils, and were exposed to house dust mites to assess the production of Gal10 and Gal3.

Results

Serum Gal10 (not Gal3) levels were significantly higher in asthmatics than in HCs (P < 0.001), in asthmatics with PAL than in those without PAL (P = 0.005), and in those with SAD than in those without SAD (P = 0.004). The Gal10-high group had significantly higher levels of peripheral CD66+ neutrophil counts, serum periostin and Gal3, and lower values of FEV1% and MMEF% than the Gal10-low group (P < 0.050 for all). The production of Gal10 and Gal3 was increased in eosinophilic airway model, while Gal10 (not Gal3) levels were increased in neutrophilic airway model as well as house dust mite stimulation.

Conclusion

Our findings suggest that serum Gal10 level may be a potential biomarker for PAL in adult asthmatics.

IL-25 induces airway remodeling in asthma by orchestrating the phenotypic changes of epithelial cell and fibrocyte

BACKGROUND

Previous studies have shown that IL-25 levels are increased in patients with asthma with fixed airflow limitation (FAL). However, the mechanism by which IL-25 contributes to airway remodeling and FAL remains unclear. Here, we hypothesized that IL-25 facilitates pro-fibrotic phenotypic changes in bronchial epithelial cells (BECs) and circulating fibrocytes (CFs), orchestrates pathological crosstalk from BECs to CFs, and thereby contributes to airway remodeling and FAL.

METHODS

Fibrocytes from asthmatic patients with FAL and chronic asthma murine models were detected using flow cytometry, multiplex staining and multispectral imaging analysis. The effect of IL-25 on BECs and CFs and on the crosstalk between BECs and CFs was determined using cell culture and co-culture systems.

RESULTS

We found that asthmatic patients with FAL had higher numbers of IL-25 receptor (i.e., IL-17RB)+-CFs, which were negatively correlated with forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC). The number of airway IL-17RB+-fibrocytes was significantly increased in ovalbumin (OVA)- and IL-25-induced asthmatic mice versus the control subjects. BECs stimulated with IL-25 exhibited an epithelial-mesenchymal transition (EMT)-like phenotypic changes. CFs stimulated with IL-25 produced high levels of extracellular matrix (ECM) proteins and connective tissue growth factors (CTGF). These profibrotic effects of IL-25 were partially blocked by the PI3K-AKT inhibitor LY294002. In the cell co-culture system, OVA-challenged BECs facilitated the migration and expression of ECM proteins and CTGF in CFs, which were markedly blocked using an anti-IL-17RB antibody.

CONCLUSION

These results suggest that IL-25 may serve as a potential therapeutic target for asthmatic patients with FAL.

Relief of ovalbumin-induced airway remodeling by the glycyl-l-histidyl-l-lysine-Cu2+ tripeptide complex via activation of SIRT1 in airway epithelial cells

Fixed airflow limitation (FAO), prevalent in patients with severe or difficult-to-treat asthma, is mainly caused by airway remodeling. Airway remodeling is initiated by inflammation and involves subsequent pathological changes. Glycyl-l-histidyl-l-lysine (GHK) is a matrikine with anti-inflammatory and antioxidant effects, naturally existing in human tissue. At present, the GHK level in human plasma and whether it is related to airway remodeling of asthma remain unclear. This study was conducted to determine how GHK is involved in airway remodeling in asthma. Our result showed that the plasma GHK levels of patients with asthma were significantly lower than those of age-matched healthy controls. In asthma patients, plasma GHK levels display a moderate correlation with FEF_25-75%, and patients with FAO had significantly lower GHK levels. Ovalbumin-induced mice of asthma model treated with PBS or GHK-Cu (a form of GHK with higher bioavailability) were used to evaluate the effect of exogenous GHK supplement on airway remodeling. GHK-Cu administration alleviated airway remodeling, as reflected by decreased peribronchial collagen deposition and airway mucus secretion, and suppressed epithelial-mesenchymal transition. The therapeutical effect related to decreased TGF-β1 level. Successively, network pharmacology and the validation data of experiments in vivo and vitro demonstrated that GHK-Cu decreased TGF-β1 level by increasing SIRT1 expression and activating SIRT1 deacetylation in airway epithelial cells, thereby alleviating airway remodeling. Collectively, decreased plasma GHK levels were related to FAO in asthma patients. Through the direct binding and activation of SIRT1, exogenous GHK-Cu administration alleviated airway remodeling in asthmatic mice.

Asthma and Fixed Airways Obstruction: Real Life Aspects

We aimed to evaluate asthmatic patients with fixed airways obstruction (FAO) and to verify the impact of follow-up in an asthma-dedicated outpatient clinic on symptoms control and spirometry compared to asthmatics without FAO. We enrolled 20 asthmatic FAO+ patients and 20 FAO- asthmatics at baseline (T0) and at a one-year follow-up visit (T1). FAO+ and FAO- groups were compared for anamnesis, FEV1, asthma control test (ACT) and their ΔT0-T1. FAO+ and FAO- groups did not differ for age, BMI, pack-years, allergy, T0 blood eosinophils, comorbidities or GINA therapy step at T0 and T1, whereas, in the FAO+ group, we found more patients with a delay >5 years between symptoms onset and correct asthma diagnosis (p < 0.05). ACT at T0 and ΔT0-T1, FEV1 at ΔT0-T1 and number of exacerbations at T0 and ΔT0-T1 did not differ between groups. Despite a widespread perception of FAO, per se, as a severity factor for asthma, we found similar severity profiles and amelioration after one year of treatment in the FAO+ and FAO- groups. The only factor linked to FAO development in our population was a delay in asthma diagnosis from respiratory symptoms onset, which may have led to airway remodeling. Physicians should characterize patients with FAO for avoiding misdiagnosis between asthma and other respiratory diseases and for establishing the appropriate therapy.

Predictors and associations of the persistent airflow limitation phenotype in asthma: a post-hoc analysis of the ATLANTIS study

BACKGROUND

Persistent airflow limitation (PAL) occurs in a subset of patients with asthma. Previous studies on PAL in asthma have included relatively small populations, mostly restricted to severe asthma, or have no included longitudinal data. The aim of this post-hoc analysis was to investigate the determinants, clinical implications, and outcome of PAL in patients with asthma who were included in the ATLANTIS study.

METHODS

In this post-hoc analysis of the ATLANTIS study, we assessed the prevalence, clinical characteristics, and implications of PAL across the full range of asthma severity. The study population included patients aged 18-65 years who had been diagnosed with asthma at least 6 months before inclusion. We defined PAL as a post-bronchodilator FEV₁/forced vital capacity (FVC) of less than the lower limit of normal at recruitment. Asthma severity was defined according to the Global Initiative for Asthma. We used Mann-Whitney U test, t test, or χ² test to analyse differences in baseline characteristics between patients with and without PAL. Logistic regression was used for multivariable analysis of the associations between PAL and baseline data. Cox regression was used to analyse risk of exacerbation in relation to PAL, and a linear mixed-effects model was used to analyse change in FEV₁ over time in patients with versus patients without PAL. Results were validated in the U-BIOPRED cohort.

FINDINGS

Between June 30, 2014 and March 3, 2017, 773 patients were enrolled in the ATLANTIS study of whom 760 (98%) had post-bronchodilator FEV₁/FVC data available. Of the included patients with available data, mean age was 44 years (SD 13), 441 (58%) of 760 were women, 578 (76%) were never-smokers, and 248 (33%) had PAL. PAL was not only present in patients with severe asthma, but also in 21 (16%) of 133 patients with GINA step 1 and 24 (29%) of 83 patients with GINA step 2. PAL was independently associated with older age at baseline (46 years in PAL group vs 43 years in non-PAL group), longer duration of asthma (24 years vs 12 years), male sex (51% vs 38%), higher blood eosinophil counts (median 0·27 × 10⁹ cells per L vs 0·20 × 10⁹ cells per L), more small airway dysfunction, and more exacerbations during 1 year of follow-up. Associations between PAL, age, and eosinophilic inflammation were validated in the U-BIOPRED cohort, whereas associations with sex, duration of asthma, and risk of exacerbations were not validated.

INTERPRETATION

PAL is not only present in severe disease, but also in a considerable proportion of patients with milder disease. In patients with mild asthma, PAL is associated with eosinophilic inflammation and a higher risk of exacerbations. Our findings are important because they suggest that increasing treatment intensity should be considered in patients with milder asthma and PAL.

FUNDING

Chiesi Farmaceutici and Dutch Ministry of Economic Affairs and Climate Policy (by means of the public-private partnership programme).

Early Features of Chronic Obstructive Pulmonary Disease in Patients with Asthma: Is there ACO before ACO?

The diagnosis of asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) is considered when a patient presents features of both asthma and COPD, usually including a component of irreversible airway obstruction (IRAO). However, some patients with asthma, particularly smokers, may have various features typical of COPD in the absence of such component of IRAO. Features of early COPD can be found at a young age in such patients even with normal spirometry. More longitudinal studies should be conducted to determine steps needed to improve clinical outcomes of these patients including the early recognition of these changes and the application of preventative/therapeutic interventions.

Prevalence of the eosinophilic phenotype among severe asthma patients in Brazil: the BRAEOS study

Objective:

To assess the prevalence of the eosinophilic and allergic phenotypes of severe asthma in Brazil, as well as to investigate the clinical characteristics of severe asthma patients in the country.

Methods:

This was a cross-sectional study of adult patients diagnosed with severe asthma and managed at specialized centers in Brazil. The study was conducted in 2019.

Results:

A total of 385 patients were included in the study. Of those, 154 had a blood eosinophil count > 300 cells/mm³ and 231 had a blood eosinophil count of ≤ 300 cells/mm³. The median age was 54.0 years, and most of the patients were female, with a BMI of 29.0 kg/m² and a history of allergy (81.6%). The prevalence of patients with a blood eosinophil count > 300 cells/mm³ was 40.0% (95% CI: 35.1-44.9), and that of those with a blood eosinophil count > 300 cells/mm³ and a history of allergy was 31.9% (95% CI: 27.3-36.6). Age and BMI showed positive associations with a blood eosinophil count > 300 cells/mm³ (OR = 0.97, p < 0.0001; and OR = 0.96, p = 0.0233, respectively), whereas the time elapsed since the onset of asthma symptoms showed an increased association with a blood eosinophil count > 300 cells/mm³ (OR = 1.02, p = 0.0011).

Conclusions:

This study allowed us to characterize the population of severe asthma patients in Brazil, showing the prevalence of the eosinophilic phenotype (in 40% of the sample). Our results reveal the relevance of the eosinophilic phenotype of severe asthma at a national level, contributing to increased effectiveness in managing the disease and implementing public health strategies.

Asthma clustering methods: a literature-informed application to the children's health study data

OBJECTIVE

The heterogeneity of asthma has inspired widespread application of statistical clustering algorithms to a variety of datasets for identification of potentially clinically meaningful phenotypes. There has not been a standardized data analysis approach for asthma clustering, which can affect reproducibility and clinical translation of results. Our objective was to identify common and effective data analysis practices in the asthma clustering literature and apply them to data from a Southern California population-based cohort of schoolchildren with asthma.

METHODS

As of January 1, 2020, we reviewed key statistical elements of 77 asthma clustering studies. Guided by the literature, we used 12 input variables and three clustering methods (hierarchical clustering, k-medoids, and latent class analysis) to identify clusters in 598 schoolchildren with asthma from the Southern California Children's Health Study (CHS).

RESULTS

Clusters of children identified by latent class analysis were characterized by exhaled nitric oxide, FEV1/FVC, FEV1 percent predicted, asthma control and allergy score; and were predictive of control at two year follow up. Clusters from the other two methods were less clinically remarkable, primarily differentiated by sex and race/ethnicity and less predictive of asthma control over time.

CONCLUSION

Upon review of the asthma phenotyping literature, common approaches of data clustering emerged. When applying these elements to the Children's Health Study data, latent class analysis clusters-represented by exhaled nitric oxide and spirometry measures-had clinical relevance over time.

Dapagliflozin mitigates ovalbumin-prompted airway inflammatory-oxidative successions and associated bronchospasm in a rat model of allergic asthma

BACKGROUND

Asthma is a chronic inflammatory lung disease that universally affects millions of people. Despite numerous well-defined medications, asthma is poorly managed. The study aimed to clarify the potential therapeutic effect of Dapagliflozin (DAPA) against lung inflammation, oxidative stress and associated bronchospasm in OVA-sensitized rat asthma model.

RESEARCH DESIGN AND METHODS

Twenty-five rats were allocated into (Control, Asthma, DEXA, DAPA, and DAPA+DEXA). All treatments were administered orally once a day for two weeks. BALF levels of IL-17, TNFα, IL-1β, and MCP-1 were determined to assess airway inflammation. For oxidative stress determination, BALF MDA levels and TAC were measured. The BALF S100A4 level and NO/sGC/cGMP pathway were detected. Lung histopathological findings and immunohistochemical investigation of eNOS and iNOS activities were recorded.

RESULTS

DAPA significantly reduced (p < 0.001) airway inflammatory-oxidative markers (IL-17, TNFα, IL-1β, MCP1, and MDA), but increased (p < 0.001) TAC, and mitigated bronchospasm by activating NO/sGC/cGMP and reducing S100A4 (p < 0.001). The biochemical and western blot studies were supported by histopathological and immunohistochemical investigations.

CONCLUSIONS

: DAPA is presenting a new prospective possibility for future asthma therapy due to its anti-inflammatory, anti-oxidant, and bronchodilator properties. DAPA has the property of reducing Dexamethasone (DEXA)-associated unfavorable effects during asthma treatment.

Normalisation of airflow limitation in asthma: Post-hoc analyses of TRIMARAN and TRIGGER

Background

In asthma, persistent airflow limitation (PAL) is associated with poorer control, lung function decline and exacerbations. Using post‐hoc analyses we evaluated: the relationship between post‐salbutamol PAL at screening, airflow limitation (AL) during 52 weeks treatment with extrafine beclometasone dipropionate/formoterol fumarate/glycopyrronium (BDP/FF/G) versus BDP/FF and the risk of moderate/severe asthma exacerbations.

Methods

TRIMARAN and TRIGGER were double‐blind studies comparing BDP/FF/G with BDP/FF (TRIMARAN medium‐dose ICS; TRIGGER high‐dose) in adults with uncontrolled asthma. Patients were subgrouped according to post‐salbutamol PAL status at screening, and AL over the 52‐week treatment period.

Results

Most patients with post‐salbutamol PAL at screening had AL at all on‐treatment visits (TRIMARAN 62.8%; TRIGGER 66.8%). A significantly higher proportion of patients had normalised airflow on ≥1 follow‐up visit when receiving BDP/FF/G than BDP/FF (TRIMARAN 44.1 vs. 33.1% [p = 0.003]; TRIGGER 40.1 vs. 26.0% [p < 0.001]). In patients with post‐salbutamol PAL at screening and normalised AL at ≥1 follow‐up visit, exacerbation rates were 15% (p = 0.105) and 19% (p = 0.039) lower in TRIMARAN and TRIGGER versus those with AL on all visits. There was a trend to lower exacerbation rates in patients receiving BDP/FF/G than BDP/FF, particularly in patients in whom AL was normalised.

Conclusion

In these analyses, AL in asthma was associated with an increased exacerbation incidence. Inhaled triple therapy with extrafine BDP/FF/G was more likely to normalise airflow, and was associated with a trend to a lower exacerbation rate than BDP/FF, particularly in the subgroup of patients in whom treatment was associated with airflow normalisation.

ClinicalTrials.gov: TRIMARAN, NCT02676076; TRIGGER, NCT02676089.

Asthma with Fixed Airflow Obstruction: From Fixed to Personalized Approach

Asthma is generally characterized by variable symptoms such as dyspnea and wheezing and variable airflow obstruction. This review focuses on a subset of patients suffering from asthma with persistent airflow limitation that is not fully reversible (asthma with fixed airflow obstruction, FAO). The pathophysiology, the risk factors and the clinical outcomes associated with FAO are presented, as well as the distinct clinical entity of severe asthma and its inflammatory subtypes (T2 and non-T2). The current strategies for the treatment of these endotypes and treatment of the distinct Asthma/COPD overlap (ACO) phenotype are described. Management and medical interventions in FAO and/or ACO patients demand a holistic approach, which is not yet clearly established in guidelines worldwide. Finally, a treatment algorithm that includes FAO/ACO management based on pharmacological and non-pharmacological treatment, guideline-based management for specific co-morbidities, and modification of the risk factors is proposed.

Omalizumab in Asthma with Fixed Airway Obstruction: Post Hoc Analysis of EXTRA

BACKGROUND

Although asthma is typically characterized by bronchodilator responsiveness (BDR), fixed airflow obstruction (FAO) occurs in ∼50% of patients with severe asthma.

OBJECTIVE

Do FAO/BDR associate with efficacy of omalizumab, a monoclonal antibody that targets IgE?

METHODS

In EXTRA, patients aged 12-75 years with inadequately controlled severe allergic asthma despite high-dose inhaled corticosteroids plus long-acting β₂-agonists were randomized to omalizumab (n = 427) or placebo (n = 423) for 48 weeks of treatment. In this post hoc analysis, high/low BDR were defined as ≥12%/<12% increases in baseline forced expiratory volume in 1 second (FEV₁) after bronchodilator administration, respectively. FAO presence (+)/absence (-) were defined as baseline postbronchodilator FEV₁/forced vital capacity <70%/≥70%, respectively. Poisson regression/analysis of covariance models were used to estimate exacerbation relative rate reductions (RRRs)/least-squares mean changes in FEV₁, respectively.

RESULTS

In patients with high BDR, omalizumab reduced exacerbations more than placebo over the 48-week treatment period regardless of FAO status (RRR [95% confidence interval (CI)]: FAO+, 59.8% [17.7-80.4%]; FAO-, 44.3% [16.6-62.8%]). Omalizumab improved FEV₁ compared with placebo in the FAO-, high BDR subgroup (FEV₁ change from baseline [95% CI] for omalizumab vs placebo, 0.065 L [-0.071 to 0.201 L] to 0.236 L [0.112-0.359 L]) across 48 weeks. This was not observed in patients with low BDR, irrespective of FAO.

CONCLUSION

Omalizumab was more efficacious than placebo at reducing exacerbations in patients with high, but not low, BDR, regardless of the presence of FAO. Lung function improvement primarily occurred in FAO-, high BDR patients, suggesting that asthma with low BDR may represent a difficult-to-treat phenotype.

The feasibility and effect of a nurse-led, patient-centered asthma education program in a Nigerian context

RATIONALE, AIMS AND OBJECTIVES

Insufficient asthma education is an unmet need in Nigeria. We aimed to assess the feasibility of a nurse-led asthma education program and its effect on asthma knowledge and outcomes in Lagos, Nigeria.

METHODS

Using a quasi-experimental study design, we recruited participants ≥12 years with physician diagnosed asthma. We assessed asthma knowledge, asthma control, medication adherence, health related quality of life and inhaler technique and also measured lung function. A trained nurse delivered asthma education sessions during the regular clinic visits and demonstrated correct inhaler technique. All assessments were repeated at 3-month. Data was analyzed with descriptive and inferential statistics. A p-value of <0.05 was considered significant for all associations.

RESULTS

Of the 80 participants at baseline, 42 (52.5%) completed the follow-up assessment and were included in the outcome analysis. Their ages ranged from 12 to 75 years, 35 (83.3%) were ≥18 years old and 30 (71.4%) were females. There was significant improvement in knowledge score immediately post intervention (15.48 ± 3.05 versus 18.33 ± 2.21, p < 0.001) and at 3 months (17.52 ± 2.63, p < 0.001). Those with uncontrolled asthma (Asthma Control Test score ≤19) had a meaningful (3.8-point) change in ACT score at follow-up. The improvement in the mean score on the Morisky Medication Adherence Scale was significant (p = 0.03), but a change of 0.48 was not considered meaningful. There was significant (p < 0.001) and meaningful (1.08) improvement in Mini Asthma Quality of Life score at 3 months. Pre-bronchodilator FEV1% predicted and scores on the inhaler technique check list for the Diskus and pressurized meter dose inhaler did not significantly change at follow-up (p = 0.38, 0.26 and 0.80 respectively).

CONCLUSION

It is practicable for nurses to deliver effective asthma education during regular clinic visits in our practice setting. This training could meaningfully improve asthma control and health related quality of life.

[Strategies for prescription of inhaled corticosteroids in mild-to-moderate asthma]

Asthma is a common respiratory condition characterized by chronic inflammation of the airways. Most asthmatics have a mild-to-moderate form of the disease, but are still at risk of severe exacerbations and significantly impaired quality of life. This article reviews the strategies for prescription of inhaled corticosteroids in patients with mild-to-moderate asthma. The definition of asthma severity, the goals of asthma management and the adjustment of therapeutics are successively addressed. The major changes proposed by the GINA group in 2019 are also discussed.

A Systematic Review of Asthma Phenotypes Derived by Data-Driven Methods

Classification of asthma phenotypes has a potentially relevant impact on the clinical management of the disease. Methods for statistical classification without a priori assumptions (data-driven approaches) may contribute to developing a better comprehension of trait heterogeneity in disease phenotyping. This study aimed to summarize and characterize asthma phenotypes derived by data-driven methods. We performed a systematic review using three scientific databases, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. We included studies reporting adult asthma phenotypes derived by data-driven methods using easily accessible variables in clinical practice. Two independent reviewers assessed studies. The methodological quality of included primary studies was assessed using the ROBINS-I tool. We retrieved 7446 results and included 68 studies of which 65% (n = 44) used data from specialized centers and 53% (n = 36) evaluated the consistency of phenotypes. The most frequent data-driven method was hierarchical cluster analysis (n = 19). Three major asthma-related domains of easily measurable clinical variables used for phenotyping were identified: personal (n = 49), functional (n = 48) and clinical (n = 47). The identified asthma phenotypes varied according to the sample’s characteristics, variables included in the model, and data availability. Overall, the most frequent phenotypes were related to atopy, gender, and severe disease. This review shows a large variability of asthma phenotypes derived from data-driven methods. Further research should include more population-based samples and assess longitudinal consistency of data-driven phenotypes.

Modern understanding of bronchial asthma with fixed airflow obstruction

The review provides data on one of the phenotypes of severe bronchial asthma it is asthma with fixed airway obstruction. According to data published today, there is no single pathway for the formation of fixed airway obstruction in patients with severe asthma. Increasing knowledge of the pathophysiology of fixed airway obstruction, as well as identifying the most significant risk factors, is essential for the successful treatment of such patients. In addition, the development of fixed obstruction is associated with a worse and sometimes fatal prognosis. Expanding the existing views is also necessary to overcome the difficulties of differential diagnosis between bronchial asthma with fixed airway obstruction and bronchial asthma in combination with COPD. All this will optimize the approach to the management of patients with bronchial asthma to prevent the formation of fixed airway obstruction.

Lung function fluctuation patterns unveil asthma and COPD phenotypes unrelated to type 2 inflammation

BACKGROUND

In all chronic airway diseases, the dynamics of airway function are influenced by underlying airway inflammation and bronchial hyperresponsiveness along with limitations in reversibility owing to airway and lung remodeling as well as mucous plugging. The relative contribution of each component translates into specific clinical patterns of symptoms, quality of life, exacerbation risk, and treatment success.

OBJECTIVE

We aimed to evaluate whether subgrouping of patients with obstructive airway diseases according to patterns of fluctuation in lung function allows identification of specific phenotypes with distinct clinical characteristics.

METHODS

We applied the novel method of fluctuation-based clustering (FBC) to twice-daily FEV₁ measurements recorded over a 1-year period in a mixed group of 134 adults with mild-to-moderate asthma, severe asthma, or chronic obstructive pulmonary disease from the European BIOAIR cohort.

RESULTS

Independently of clinical diagnosis, FBC divided patients into 4 fluctuation-based clusters with progressively increasing alterations in lung function that corresponded to patterns of increasing clinical severity, risk of exacerbation, and lower quality of life. Clusters of patients with airway disease with significantly elevated levels of biomarkers relating to remodeling (osteonectin) and cellular senescence (plasminogen activator inhibitor-1), accompanied by a loss of airway reversibility, pulmonary hyperinflation, and loss of diffusion capacity, were identified. The 4 clusters generated were stable over time and revealed no differences in levels of markers of type 2 inflammation (blood eosinophils and periostin).

CONCLUSION

FBC-based phenotyping provides another level of information that is complementary to clinical diagnosis and unrelated to eosinophilic inflammation, which could identify patients who may benefit from specific treatment strategies or closer monitoring.

Asthma with Irreversible Airway Obstruction in Smokers and Nonsmokers: Links between Airway Inflammation and Structural Changes

BACKGROUND

The development of irreversible airway obstruction (IRAO) in asthma is related to lung/airway inflammatory and structural changes whose characteristics are likely influenced by exposure to tobacco smoke.

OBJECTIVE

To investigate the interplay between airway and lung structural changes, airway inflammation, and smoking exposure in asthmatics with IRAO.

METHODS

We studied asthmatics with IRAO who were further classified according to their smoking history, those with ≥20 pack-years of tobacco exposure (asthmatics with smoking-related IRAO [AwS-IRAO]) and those with <5 pack-years of tobacco exposure (asthmatics with nonsmoking-related IRAO [AwNS-IRAO]). In addition to recording baseline clinical and lung function features, all patients had a chest computed tomography (CT) from which airway wall thickness was measured and quantitative and qualitative assessment of emphysema was performed. The airway inflammatory profile was documented from differential inflammatory cell counts on induced sputum.

RESULTS

Ninety patients were recruited (57 AwS-IRAO and 33 AwNS-IRAO). There were no statistically significant differences in the extent of emphysema and gas trapping between groups on quantitative chest CT analysis, although Pi10, a marker of airway wall thickness, was significantly higher in AwS-IRAO (p = 0.0242). Visual analysis showed a higher prevalence of emphysema (p = 0.0001) and higher emphysema score (p < 0.0001) in AwS-IRAO compared to AwNS-IRAO and distribution of emphysema was different between groups. Correlations between radiological features and lung function were stronger in AwS-IRAO. In a subgroup analysis, we found a correlation between airway neutrophilia and emphysematous features in AwS-IRAO and between eosinophilia and both airway wall thickness and emphysematous changes in AwNS-IRAO.

CONCLUSIONS

Although bronchial structural changes were relatively similar in smoking and nonsmoking patients with asthma and IRAO, emphysematous changes were more predominant in smokers. However, neutrophils in AwS-IRAO and eosinophils in AwNS-IRAO were associated with lung and airway structural changes.

Inflammatory patterns in fixed airflow obstruction are dependent on the presence of asthma

RATIONALE

Fixed airflow obstruction (FAO) can complicate asthma. Inflammation is a proposed underlying mechanism.

OBJECTIVE

Our aim in this cross-sectional investigation was to evaluate the blood leucocyte pattern and level of exhaled nitric oxide in asthmatics and non-asthmatics with or without FAO.

METHODS

A total of 11,579 individuals aged ≥20 years from the US National Health and Nutrition Examination Survey were included. They were grouped as: controls without asthma and FAO (n = 9,935), asthmatics without FAO (n = 674), asthmatics with FAO (n = 180) and non-asthmatics with FAO (n = 790). FAO was defined as post-bronchodilator FEV1/FVC < lower limit of normal. Exhaled nitric oxide ≥ 25ppb, blood eosinophil levels ≥300 cells/μL, and blood neutrophil levels ≥5100 cells/μL were defined as elevated. Stratified analyses for smoking and smoking history were performed.

RESULTS

Elevated blood eosinophil levels were more common in all groups compared to the controls, with the highest prevalence in the group with asthma and fixed airflow obstruction (p<0.01). In a multiple logistic regression model adjusted for potential confounders including smoking, the asthma groups had significantly higher odds ratios for elevated B-Eos levels compared to the control group (odds ratio 1.4, (confidence interval: 1.1-1.7) for the asthma group without fixed airflow obstruction and 2.5 (1.4-4.2) for the asthma group with fixed airflow obstruction). The group with fixed airflow obstruction without asthma had higher odds ratio for elevated blood neutrophil levels compared to the controls: 1.4 (1.1-1.8). Smoking and a history of smoking were associated to elevated B-Neu levels.

CONCLUSION

Fixed airflow obstruction in asthma was associated with elevated blood eosinophil levels, whereas fixed airflow obstruction without asthma was associated with elevated blood neutrophil levels.

Systematic Assessment of Difficult-to-Treat Asthma: Principles and Perspectives

Difficult-to-treat asthma affects a minority of adults and children with asthma but represents a challenging mix of misdiagnosis, multimorbidity, inadequate self-management, severe airway pathobiology, and treatment complications. Management of these patients extends beyond asthma pharmacotherapy, because multiple other patient-related domains need to be addressed as well. Such complexity can hinder adequate clinical assessment even when performed in specialist practice. Systematic assessment undertaken by specialized multidisciplinary teams brings a broad range of resources to bear on patients with difficult-to-treat asthma. Although the concept of systematic assessment is not new, practices vary considerably and implementation is not universal. Nevertheless, assessment protocols are already in place in several institutions worldwide, and outcomes after such assessments have been highly encouraging. This review discusses the rationale, components, and benefits of systematic assessment, outlining its clinical utility and the available evidence for improved outcomes. It describes a range of service configurations and assessment approaches, drawing examples from severe asthma centers around the world to highlight common essential elements. It also provides a framework for establishing such services and discusses practical considerations for implementation.

Risk factors for fixed airflow obstruction in children and adolescents with asthma: 4-Year follow-up

BACKGROUND

Asthma is a disease with reversible bronchoconstriction; however, some patients develop fixed airflow obstruction (FAO). Previous studies have reported the incidence and risk factors of FAO in adults; however, the corresponding factors in children remain poorly understood.

AIM

To evaluate the incidence and risk factors of FAO in children and adolescents with asthma.

METHOD

Observational and prospective cohort study with a 4-year follow-up of clinically stable patients with asthma (from 6-8 years old). Anthropometric data, history of asthma, number of hospitalizations, frequent exacerbations, asthma severity, asthma control, inhaled corticosteroid dose, atopy, and lung function were analyzed as potential risk factors for FAO. FAO was defined by a ratio of the forced expiratory volume in the first second to the forced vital capacity below the lower limit of normal, even after inhaled and oral corticosteroid treatment.

RESULTS

Four hundred and twenty-eight patients were recruited, and 358 were analyzed. The FAO incidence in children and adolescents with asthma was 9.5% (n = 34), starting at 10 years of age. Age, body mass index, hospitalizations for asthma, bronchodilator response, frequent exacerbations, length of exacerbations, and asthma severity were associated with FAO. Frequent exacerbations (odds ratio [OR] = 4.0; 95% confidence interval [CI] = 1.3-11.7) and asthma severity categorized as steps 4 to 5 (OR = 3.5; 95% CI = 1.6-7.6) remained risk factors.

CONCLUSIONS

Frequent exacerbations and asthma severity are the risk factors for FAO in children and adolescents with asthma.

Endothelial Activation, Innate Immune Activation, and Inflammation Are Associated With Postbronchodilator Airflow Limitation and Obstruction Among Adolescents Living With HIV

BACKGROUND

Chronic inflammation, innate immune activation, T-cell imbalance and endothelial activation have been linked with lung diseases. We sought to determine whether markers of these pathophysiologic pathways were associated with spirometry and chest computed tomography (CT) abnormalities among adolescents living with HIV (ALWH).

SETTING

Coptic Hope Center for Infectious Diseases in Nairobi, Kenya.

METHODS

We performed a cross-sectional study of ALWH (10-19 years old). Participants underwent chest CT, spirometry, and venipuncture for serum biomarkers. We also collected demographic, anthropometric, T-cell subset, antiretroviral therapy, and exposure data. We compared characteristics and biomarkers by airflow obstruction [postbronchodilator FEV1/FVC z-score (zFEV1/FVC) < -1.64]. We used multivariable linear regression to determine associations of log10-transformed biomarkers and chest CT abnormalities with lower postbronchodilator zFEV1/FVC (airflow limitation). We performed exploratory principal components analysis on biomarkers, and determined associations of factors with postbronchodilator zFEV1/FVC and chest CT abnormalities.

RESULTS

Of 47 participants with acceptable quality spirometry, 21 (45%) were female, median age was 13 years and 96% had perinatally-acquired HIV. Median CD4 was 672 cells/µL. Overall, 28% had airflow obstruction and 78% had a chest CT abnormality; airflow obstruction was associated with mosaic attenuation (P = 0.001). Higher endothelial activation (sVCAM-1, sICAM-1), inflammation and innate immune activation (serum amyloid-A, sTREM-1, sCD163), and T-cell imbalance (lower CD4/CD8) markers were associated with airflow limitation. Factors comprising endothelial and innate immune activation were associated with airflow limitation.

CONCLUSIONS

Endothelial activation, innate immune activation, T-cell imbalance, and chronic inflammation are associated with airflow limitation and obstruction, providing insights into chronic lung disease pathophysiology among ALWH.

Defining severe obstructive lung disease in the biologic era: an endotype-based approach

Severe obstructive lung disease, which encompasses asthma, chronic obstructive pulmonary disease (COPD) or features of both, remains a considerable global health problem and burden on healthcare resources. However, the clinical definitions of severe asthma and COPD do not reflect the heterogeneity within these diagnoses or the potential for overlap between them, which may lead to inappropriate treatment decisions. Furthermore, most studies exclude patients with diagnoses of both asthma and COPD. Clinical definitions can influence clinical trial design and are both influenced by, and influence, regulatory indications and treatment recommendations. Therefore, to ensure its relevance in the era of targeted biologic therapies, the definition of severe obstructive lung disease must be updated so that it includes all patients who could benefit from novel treatments and for whom associated costs are justified. Here, we review evolving clinical definitions of severe obstructive lung disease and evaluate how these have influenced trial design by summarising eligibility criteria and primary outcomes of phase III randomised controlled trials of biologic therapies. Based on our findings, we discuss the advantages of a phenotype- and endotype-based approach to select appropriate populations for future trials that may influence regulatory approvals and clinical practice, allowing targeted biologic therapies to benefit a greater proportion and range of patients. This calls for co-ordinated efforts between investigators, pharmaceutical developers and regulators to ensure biologic therapies reach their full potential in the management of severe obstructive lung disease.

Impact of airflow obstruction on long-term mortality in patients with asthma in Japan

BACKGROUND

The long-term prognosis of asthma with airflow obstruction is poorly understood in Japan. The aim of this retrospective 26-year study was to investigate the long-term mortality risk of airflow obstruction in asthmatics.

METHODS

Using data from the Omuta City Air Pollution-related Health Damage Cohort Program, mortality risk ratios of airflow obstruction in Japanese Individuals were analyzed by Cox proportional hazards models. Airflow obstruction was considered to be present when the forced expiratory volume in 1 sec (FEV₁)/forced vital capacity ratio was <0.7 and FEV₁ predicted was <80% based on spirometry.

RESULTS

Among the 3146 victims with chronic respiratory diseases, 697 with adult asthma were selected. Median follow-up period was 26.3 (range 0.9-40.9) years. The airflow obstruction group (n = 193) showed significantly higher rates of mortality related to respiratory problems (risk ratio [95% confidence interval] 1.51 [1.86-1.93], P = 0.0017) and asthma attacks (1.86 [1.30-2.66], P = 0.0011) than the without airflow obstruction group (n = 504). Airflow obstruction was an independent risk factor for both respiratory-related (1.84 [1.36-2.49], P = 0.0001) and all-cause (1.44 [1.17-1.76], P = 0.0008) mortality after adjustment for age, sex, body mass index, and smoking status. More severe airflow obstruction was significantly associated with poorer prognosis.

CONCLUSIONS

This long-term cohort program revealed the impacts of asthma with airflow obstruction as an independent mortality risk. Findings suggest that intervention and prevention of airflow obstruction can reduce long-term mortality in patients with asthma.

Distinct asthma phenotypes with low maximal attainment of lung function on cluster analysis

OBJECTIVE

Asthma is a heterogeneous disease with varying clinical presentations, severity and ability to achieve asthma control. The present study aimed to characterize clinical phenotypes of asthma in an Indian cohort of subjects using a cluster analysis approach.

METHODS

Patients with confirmed asthma (N = 100) and at least 6-months of follow-up data, identified by retrospective chart review, were included in this study. Demographics, age at disease onset, disease duration, body mass index, serial spirometry and allergen sensitization were assessed. Asthma control was assessed prospectively using Global Initiative for Asthma and Asthma Control Test. R version 3.4.3 was used for statistical analysis. Ward's minimum-variance hierarchical clustering method was performed using an agglomerative (bottom-up) approach. To compare differences between clusters, analysis of variance using Kruskal-Wallis test (continuous variables) and chi-square test (categorical variables) was used.

RESULTS

Cluster analysis of 100 treatment-naive patients with asthma identified four clusters. Cluster 1, (N = 40), childhood onset of disease, normal body weight, equal gender distribution and achieved normal lung function. Cluster 2 (N = 16) included adolescent disease-onset, obese, majority males and had poor attainment of maximum lung functions. Cluster 3 (N = 20) were older, late-onset of disease, obese, majority male and had poor attainment of maximum lung function. Cluster 4 (N = 24) had adult-onset of disease, obese, predominantly female and achieved normal lung function.

CONCLUSIONS

In an Indian cohort of well-characterized patients with asthma, cluster analysis identified four distinct clinical phenotypes of asthma, two of which had poor attainment of maximum lung functions.

Approaches to Asthma Diagnosis in Children and Adults

Although the hallmark features of asthma include reversible airflow obstruction, airway eosinophilia, and symptoms of recurrent wheeze associated with breathlessness and cough, it is a heterogeneous disease. The extent of the pathophysiological abnormalities are variable between patients. Despite this, until recently, asthma diagnosis had been made very simplistically predominantly from a clinical history and examination, and often a trial of medication such as short acting bronchodilators. The limitations of this approach have become increasingly apparent with evidence of inappropriate over diagnosis, under diagnosis and misdiagnosis. Although there is no gold standard single test to make a diagnosis of asthma, there are several objective tests that can be used to support the diagnosis including physiological measures such as obstructive spirometry associated with bronchodilator reversibility and airway hyperresponsiveness. In addition, non-invasive tests of airway inflammation such as exhaled nitric oxide or peripheral blood eosinophils are important to identify those with an allergic or eosinophilic phenotype. Diagnostic guidelines reflect the importance of using objective tests to support a diagnosis of asthma, however practical application in the clinic may not be straightforward. The focus of this review is to discuss the need to undertake objective tests in all patients to support asthma diagnosis and not just rely on clinical features. The advantages, challenges and limitations of performing tests of lung function and airway inflammation in the clinic, the difficulties related to training and interpretation of results will be explored, and the utility and relevance of diagnostic tests will be compared in adults and children.

Towards precision medicine in severe asthma: Treatment algorithms based on treatable traits

Asthma is a common disease, and although its clinical manifestations may be similar among patients, recent research discoveries have shown that it consists of several distinct clinical clusters or phenotypes, each with different underlying molecular pathways yielding different treatment responses. Based on these observations, an alternative approach - known as 'precision medicine' - has been proposed for the management of patients with severe asthma. Precision medicine advocates identification of treatable traits, linking them to therapeutic approaches targeting genetic, immunological, environmental, and/or lifestyle factors in individual patients. The main "goal" of this personalised approach is to enable choosing a treatment which will be more likely to produce a beneficial response in the individual patient rather than a 'one size fits all' approach. The aim of the present review is to discuss different ways of phenotyping asthma and to provide a rationale for treatment algorithms based on principles of precision medicine.

Targeted Therapy for Severe Asthma: Identifying the Right Patients

Asthma affects over 300 million people worldwide. Most asthmatics are well controlled with inhaled corticosteroids and long-acting beta-agonists; however, a proportion of patients are unresponsive and attain limited disease control. This group represents a considerable healthcare and financial burden, particularly patients who experience frequent exacerbations and require hospital admission. Development of new biological agents and disease biomarkers has provided novel avenues for treatment. These treatments have been highly successful, reducing exacerbations and yielding modest improvements in quality of life and lung function. However, only a proportion of severe asthmatics respond to this targeted treatment, highlighting the heterogeneity of severe asthma. One of the first biological therapies targeted immunoglobulin E (IgE) and demonstrated modest benefit but could only be used in a subgroup of patients. Recent research has shown that treatment aimed at the T helper-2-(Th₂)-high pathways and cytokines such as interleukin (IL)-5, IL-4, and IL-13 may also be effective in another partially overlapping subgroup. A blood eosinophil count over a defined threshold (generally ≥300 cells/μl) was a reliable biomarker and identified the majority of responders in this group. Further discovery and validation of biological markers to define asthmatic phenotypes that may benefit from biological treatments remain an area of intense interest and research. We review the latest information pertaining to biological agents and demonstrate how patient responders may potentially be identified for treatment.

Identification and validation of asthma phenotypes in Chinese population using cluster analysis

BACKGROUND

Asthma is a heterogeneous airway disease, so it is crucial to clearly identify clinical phenotypes to achieve better asthma management.

OBJECTIVE

To identify and prospectively validate asthma clusters in a Chinese population.

METHODS

Two hundred eighty-four patients were consecutively recruited and 18 sociodemographic and clinical variables were collected. Hierarchical cluster analysis was performed by the Ward method followed by k-means cluster analysis. Then, a prospective 12-month cohort study was used to validate the identified clusters.

RESULTS

Five clusters were successfully identified. Clusters 1 (n = 71) and 3 (n = 81) were mild asthma phenotypes with slight airway obstruction and low exacerbation risk, but with a sex differential. Cluster 2 (n = 65) described an "allergic" phenotype, cluster 4 (n = 33) featured a "fixed airflow limitation" phenotype with smoking, and cluster 5 (n = 34) was a "low socioeconomic status" phenotype. Patients in clusters 2, 4, and 5 had distinctly lower socioeconomic status and more psychological symptoms. Cluster 2 had a significantly increased risk of exacerbations (risk ratio [RR] 1.13, 95% confidence interval [CI] 1.03-1.25), unplanned visits for asthma (RR 1.98, 95% CI 1.07-3.66), and emergency visits for asthma (RR 7.17, 95% CI 1.26-40.80). Cluster 4 had an increased risk of unplanned visits (RR 2.22, 95% CI 1.02-4.81), and cluster 5 had increased emergency visits (RR 12.72, 95% CI 1.95-69.78). Kaplan-Meier analysis confirmed that cluster grouping was predictive of time to the first asthma exacerbation, unplanned visit, emergency visit, and hospital admission (P < .0001 for all comparisons).

CONCLUSION

We identified 3 clinical clusters as "allergic asthma," "fixed airflow limitation," and "low socioeconomic status" phenotypes that are at high risk of severe asthma exacerbations and that have management implications for clinical practice in developing countries.

Characteristics of non-smoking adult asthma patients with chronic airflow limitation

OBJECTIVE

Chronic airflow limitation (CAL) can develop in a subgroup of patients with asthma. Characterising these patients is important because reduced lung function is a risk factor for adverse asthma outcomes. We hypothesised that heterogeneity in patients with CAL may be influenced by age at asthma onset. We first compared never-smoking asthma patients with and without CAL, and subsequently examined the differences between patients with late and early-onset asthma within the CAL cohort.

METHODS

Patients seen in our hospital's respiratory clinic between 1 Jan 2015 and 31 December 2015 were recruited to the study. CAL was defined as post-bronchodilator forced expiratory volume in 1 second (FEV1)<80% predicted, in the presence of post-bronchodilator ratio <70%. Variables independently associated with CAL were determined using a multivariate logistic regression model. Comparisons between patients with late-onset asthma (age ≥18 years) and early-onset asthma were made within the CAL cohort.

RESULTS

247 patients were included in the study. Age was the only variable independently associated with CAL after regression analysis, with an increase in odds of 3.8% (95% CI 0.4-7.3%) for every 1 year increase in age, p = 0.027. 63.2% of patients with CAL had late-onset asthma. Compared to patients with early-onset asthma, those with late-onset asthma had higher fractional exhaled nitric oxide levels (43 ± 32 ppb vs 20 ± 8 pb, p = 0.008).

CONCLUSIONS

An increase in age is associated with CAL in never-smoking asthma patients. In addition, age at asthma onset appears to influence airway inflammation in patients with CAL.

Comparative prevalence of co-morbidities in smoking and non-smoking asthma patients with incomplete reversibility of airway obstruction, non-smoking asthma patients with complete reversibility of airway obstruction and COPD patients

BACKGROUND

Asthma with incomplete reversibility of airway obstruction (IRAO) may often be associated to smoking-induced changes. Nevertheless, a high proportion of patients showing IRAO have never smoked. These patients with IRAO often share features of patients with chronic obstructive pulmonary disease (COPD). Although IRAO is still a poorly defined condition, it has been associated with a higher morbidity and mortality than asthma with complete reversibility of airway obstruction (CRAO) or even COPD alone. A high prevalence of comorbidities could contribute to the reported poorer clinical outcome in IRAO, in comparison to CRAO or COPD alone.

AIM

To determine the prevalence of past and current comorbidities in IRAO patients compared to patients with CRAO or COPD.

METHODS

This was a retrospective, cross-sectional study. Demographic data, clinical characteristics and 36 predetermined comorbidities documented from self-report and chart review, were recorded from smoking-associated IRAO (S-IRAO), non-smoking IRAO (NS-IRAO), CRAO and COPD patients.

RESULTS

A total of 199 patients were included in the final analysis (111F/88M, mean (±SD) age of 63 ± 10 years). The CRAO group had more comorbidities than the three other groups, but this difference was significant only with the NS-IRAO group (P = 0.04). For most comorbidities, the prevalence of comorbidities in both IRAO sub-groups was intermediate between CRAO and COPD, with significant differences between S-IRAO and NS-IRAO only for hypertension (P = 0.03), nasal polyps (P = 0.002) and pneumonia (P = 0.04). Typical asthma-associated comorbidities tended to be more prevalent in NS-IRAO patients and COPD-associated comorbidities in S-IRAO patients.

CONCLUSION

In this study, the prevalence of comorbidities was not superior in patients with IRAO, compared to those with CRAO or COPD alone. The prevalence of comorbidities in the two main types of IRAO patients reflects exposure to cigarette smoke and asthma-related mechanisms.

Targeting patients with asthma for omalizumab therapy: choosing the right patient to get the best value for money

The asthma syndrome has many manifestations, termed phenotypes, that arise by specific cellular and molecular mechanisms, termed endotypes. Understanding an individual's asthma phenotype helps clinicians make rational therapeutic decisions while the understanding of endotypes has led to the development of specific precision medications. Allergic asthma is an example of an asthma phenotype and omalizumab, a monoclonal antibody that neutralizes serum immunoglobulin (Ig)E, is a specific targeted treatment which was developed as a result of an understanding of the endotype of allergic asthma. Omalizumab has been widely used in clinical practice in Europe for over a decade as an add-on therapy to treat patients who have severe refractory allergic asthma. Over this period, many centres have reported their experience with omalizumab as an add-on therapy in patients with severe asthma. These 'real world' clinical effectiveness studies have confirmed the benefits, cost-effectiveness and clinical utility of this medication. Combining the outcomes of both sources of research has yielded important insights that may benefit patients with severe asthma, clinicians who treat them, as well as the funding agencies that reimburse the cost of this medication. The purpose of this review is to describe how to identify and evaluate a patient with asthma for whom treatment with omalizumab may be of clinical and cost-effective benefit. The assessment and investigations used to confirm allergic asthma, the objective assessment of adherence to asthma therapy and the expected benefits of add-on omalizumab treatment are described.

Asthma-chronic obstructive pulmonary disease overlap syndrome - Literature review and contributions towards a Portuguese consensus

INTRODUCTION

Phenotypic overlap between the two main chronic airway pulmonary diseases, asthma and chronic obstructive pulmonary disease (COPD), has been the subject of debate for decades, and recently the nomenclature of asthma-COPD overlap syndrome (ACOS) was adopted for this condition. The definition of this entity in the literature is, however, very heterogeneous, it is therefore important to define how it applies to Portugal.

METHODS

A literature review of ACOS was made in a first phase resulting in the drawing up of a document that was later submitted for discussion among a panel of chronic lung diseases experts, resulting in reflexions about diagnosis, treatment and clinical guidance for ACOS patients.

RESULTS

There was a consensus among the experts that the diagnosis of ACOS should be considered in the concomitant presence of: clinical manifestations characteristic of both asthma and COPD, persistent airway obstruction (post-bronchodilator FEV₁/FVC<0.7), positive response to bronchodilator test (increase in FEV₁ of ≥200mL and ≥12% from baseline) and current or past history of smoking or biomass exposure. In reaching diagnosis, the presence of peripheral eosinophilia (>300eosinophils/μL or >5% of leukocytes) and previous history of atopy should also be considered. The recommended first line pharmacological treatment in these patients is the ICS/LABA association; if symptomatic control is not achieved or in case of clinical severity, triple therapy with ICS/LABA/LAMA may be used. An effective control of the exposure to risk factors, vaccination, respiratory rehabilitation and treatment of comorbidities is also important.

CONCLUSIONS

The creation of initial guidelines on ACOS, which can be applied in the Portuguese context, has an important role in the generation of a broad nationwide consensus. This will give, in the near future, a far better clinical, functional and epidemiological characterization of ACOS patients, with the ultimate goal of achieving better therapeutic guidance.

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

The effect of systemic inflammation and comorbidities on treatment and outcome of adult-onset asthma remains unknown and is the objective of this study.As part of the Seinäjoki Adult Asthma Study (SAAS) with a 12-year follow-up, serum interleukin (IL)-6, high-sensitivity C-reactive protein (hsCRP) and lung function were measured and clinical information on comorbidities and medication collected from 170 patients with adult-onset asthma without chronic obstructive pulmonary disease.At follow-up visit, 54% of the patients had systemic inflammation as indicated by elevated IL-6 or hsCRP, 58% had at least one comorbidity and 30% at least two comorbidities (other than asthma related). Patients with systemic inflammation were treated with higher dose of inhaled corticosteroid (ICS) and they had lower lung function and higher blood neutrophils compared with patients without. Patients having ≥2 comorbidities had lower Asthma Control Test score and this association remained significant in adjusted analysis. Patients with both systemic inflammation and comorbidities showed poorest outcome of asthma. In multivariate regression analysis, high ICS dose was predicted by elevated IL-6, elevated blood neutrophils and eosinophils and poorer lung function at baseline and follow-up.Altogether, in patients with adult-onset asthma, elevated IL-6 was associated with use of high-dose ICS while multi-morbidity was linked to worse symptoms of asthma.

The asthma-COPD overlap syndrome: do we really need another syndrome in the already complex matrix of airway disease?

The term asthma–COPD overlap syndrome (ACOS) is one of multiple terms used to describe patients with characteristics of both COPD and asthma, representing ~20% of patients with obstructive airway diseases. The recognition of both sets of morbidities in patients is important to guide practical treatment decisions. It is widely recognized that patients with COPD and coexisting asthma present with a higher disease burden, despite the conceptual expectation that the “reversible” or “treatable” component of asthma would allow for more effective management and better outcomes. However, subcategorization into terms such as ACOS is complicated by the vast spectrum of heterogeneity that is encapsulated by asthma and COPD, resulting in different clinical clusters. In this review, we discuss the possibility that these different clusters are suboptimally described by the umbrella term “ACOS”, as this additional categorization may lead to clinical confusion and potential inappropriate use of resources. We suggest that a more clinically relevant approach would be to recognize the extreme variability and the numerous phenotypes encompassed within obstructive airway diseases, with various degrees of overlapping in individual patients. In addition, we discuss some of the evidence to be considered when making practical decisions on the treatment of patients with overlapping characteristics between COPD and asthma, as well as the potential options for phenotype and biomarker-driven management of airway disease with the aim of providing more personalized treatment for patients. Finally, we highlight the need for more evidence in patients with overlapping disease characteristics and to facilitate better characterization of potential treatment responders.

Blurred lines. Eosinophilic COPD: ACOS or COPD phenotype?

Because asthma and COPD are both inflammatory chronic obstructive airway diseases, there are several clinical expressions which can cause confusion, such as: eosinophilic asthma with fixed obstruction, which is a risk factor and might progress to COPD; eosinophilic COPD; COPD with partial reversible obstruction with no asthmatic component and also eosinophilic asthma-COPD overlap syndrome (ACOS). While at the two extremes of these disorders the pathoimmunological processes are clearly different, in some patients there is overlap and the pathophysiological border between asthma and COPD is fused (or diffuse). The current guidelines are clearly insufficient for classification of the obstructive patients and, taking into account that binary separation between the two diseases is not completely clear, we should resist the temptation to label patients as ACOS and consider new airway disease taxonomy. Regardless of the condition concerned, eosinophils should be considered in the algorithm approach to obstructive patients: in COPD, as in asthma, they are related to the underlying pathological process; they have prognostic value and are related to therapeutic response. Therefore, eosinophils should be valued as useful biomarkers and included in a multidimensional diagnostic and therapeutic approach, bearing in mind the phenotypic, immunopathological and functional complexity of chronic obstructive airway disease.