Blood eosinophil counts and the development of obstructive lung disease: the Kangbuk Samsung Health Study

Gut microbiota in chronic obstructive pulmonary disease varies by CT-verified emphysema status

Background and aim

The association of the gut microbiota to chronic obstructive pulmonary disease (COPD) phenotypes is underexplored. We aimed to compare stool samples from patients with COPD and subjects without COPD and relate findings to emphysema status, exacerbation rate, blood eosinophil levels, symptom score, and lung function.

Methods

We report findings from a single-centre case-control study with 62 current and former smoking patients with COPD and 49 subjects without COPD. DNA was extracted from stool samples, and the V3V4-region of the bacterial 16S-rRNA gene was sequenced. Emphysema was defined based on thoracic computed tomography (CT thorax) low attenuating areas ≥/<10% at threshold -950 and -910 hounsfield units, respectively. Differential abundance of taxa was evaluated using Analysis of Composition of Microbes with Bias Correction (ANCOM-BC). Beta diversity was compared using a distance-based permanova-test.

Results

The genus Veillonella was decreased and a genus belonging to class Clostridia was increased in COPD compared with controls without COPD. The composition of microbes (beta diversity) differed in emphysema compared to controls, and 27 genera were differentially abundant in emphysema vs. controls. Nine of these genera belonged to the family Lachnospiraceae. Lung function, blood counts and COPD assessment test score correlated with several genera's relative abundance. Of the genera showing significant correlation to lung function, nine belonged to the family Lachnospiraceae.

Conclusion

The gut microbiota in COPD differs from that in healthy individuals, even more so in emphysema. In particular, future studies should look into the mechanisms and therapeutic potential of dysbiosis affecting the family Lachnospiraceae.

Biologics and airway remodeling in asthma: early, late, and potential preventive effects

Although airway remodeling in severe and/or fatal asthma is still considered irreversible, its individual components as a cause of clinical symptoms and/or lung function changes remain largely unknown. While inhaled glucocorticoids have not consistently been shown to affect airway remodeling, biologics targeting specific pathways of airway inflammation have been shown to improve lung function, mucus plugging, and airway structural changes that can exceed those seen with glucocorticoids. This superiority of biologic treatment, which cannot be solely explained by insufficient doses or limited durations of glucocorticoid therapies, needs to be further explored. For this field of research, we propose a novel classification of the potential effects of biologics on airway remodeling into three temporal effects: early effects (days to weeks, primarily modulating inflammatory processes), late effects (months to years, predominantly affecting structural changes), and potential preventive effects (outcomes of early treatment with biologics). For the identification of potential preventive effects of biologics, we call for studies exploring the impact of early biological treatment on airway remodeling in patients with moderate-to-severe asthma, which should be accompanied by a long-term evaluation of clinical parameters, biomarkers, treatment burden, and socioeconomic implications.

The relevance of eosinophils in chronic obstructive pulmonary disease: inflammation, microbiome, and clinical outcomes

Chronic obstructive pulmonary disease is caused by the inhalation of noxious particles such as cigarette smoke. The pathophysiological features include airway inflammation, alveolar destruction, and poorly reversible airflow obstruction. A subgroup of patients with chronic obstructive pulmonary disease has higher blood eosinophil counts, associated with an increased response to inhaled corticosteroids and increased biomarkers of pulmonary type 2 inflammation. Emerging evidence shows that patients with chronic obstructive pulmonary disease with increased pulmonary eosinophil counts have an altered airway microbiome. Higher blood eosinophil counts are also associated with increased lung function decline, implicating type 2 inflammation in progressive pathophysiology in chronic obstructive pulmonary disease. We provide a narrative review of the role of eosinophils and type 2 inflammation in the pathophysiology of chronic obstructive pulmonary disease, encompassing the lung microbiome, pharmacological targeting of type 2 pathways in chronic obstructive pulmonary disease, and the clinical use of blood eosinophil count as a chronic obstructive pulmonary disease biomarker.

Type 2 Biomarkers and Their Clinical Implications in Bronchiectasis: A Prospective Cohort Study

PURPOSE

Bronchiectasis is predominantly marked by neutrophilic inflammation. The relevance of type 2 biomarkers in disease severity and exacerbation risk is poorly understood. This study explores the clinical significance of these biomarkers in bronchiectasis patients.

METHODS

In a cross-sectional cohort study, bronchiectasis patients, excluding those with asthma or allergic bronchopulmonary aspergillosis, underwent clinical and radiological evaluations. Bronchoalveolar lavage samples were analyzed for cytokines and microbiology. Blood eosinophil count (BEC), serum total immunoglobulin E (IgE), and fractional exhaled nitric oxide (FeNO) were measured during stable disease states. Positive type 2 biomarkers were defined by established thresholds for BEC, total IgE, and FeNO.

RESULTS

Among 130 patients, 15.3% demonstrated BEC ≥ 300 cells/μL, 26.1% showed elevated FeNO ≥ 25 ppb, and 36.9% had high serum total IgE ≥ 75 kU/L. Approximately 60% had at least one positive type 2 biomarker. The impact on clinical characteristics and disease severity was variable, highlighting BEC and FeNO as reflective of different facets of disease severity and exacerbation risk. The combination of low BEC with high FeNO appeared to indicate a lower risk of exacerbation. However, Pseudomonas aeruginosa colonization and a high neutrophil-to-lymphocyte ratio (NLR ≥ 3.0) were identified as more significant predictors of exacerbation frequency, independent of type 2 biomarker presence.

CONCLUSIONS

Our study underscores the distinct roles of type 2 biomarkers, highlighting BEC and FeNO, in bronchiectasis for assessing disease severity and predicting exacerbation risk. It advocates for a multi-biomarker strategy, incorporating these with microbiological and clinical assessments, for comprehensive patient management.

Elevated Proportions of Circulating CXCR5+ Follicular Helper T Cells Reflect the Presence of Airway Obstruction in Asthma

Materials and Methods

Using flow cytometry, we identified and quantified Group 2 innate lymphocytes, T helper 2 cells, follicular helper T cells, and T helper 17 cells in peripheral blood samples from 49 individuals with asthma. We then conducted cross-sectional analyses to assess relationships between levels of these immune cells and lung function parameters, including the percentage predicted forced expiratory volume in 1 s (%FEV1). We also examined correlations between the proportions of immune cells and type 2 biomarkers.

Results

Proportions of CXCR5+ follicular helper T cells in human peripheral blood, as opposed to Group 2 innate lymphoid cells (ILC2) or T helper 2 cells, were significantly higher in cases with %FEV1 < 80% compared to those with %FEV1 ≥ 80%. Further, these proportions correlated negatively with %FEV1 and positively with blood eosinophil counts.

Conclusions

The proportion of circulating follicular helper T cells, but not T helper 2 cells or Group 2 innate lymphoid cells, may reflect the presence of airway obstruction caused by persistent type 2 inflammation.

Clinical Characteristics and 2-Year Outcomes of Chronic Obstructive Pulmonary Disease Patients With High Blood Eosinophil Counts: A Population-based Prospective Cohort Study in China

BACKGROUND

High blood eosinophil count (BEC) is a useful biomarker for guiding inhaled corticosteroid therapy in patients with chronic obstructive pulmonary disease (COPD), yet its implications in a community setting remain underexplored. This study aimed to elucidate the clinical characteristics and outcomes of COPD patients with high BEC within the Chinese community.

METHODS

We obtained baseline and 2-year follow-up data from COPD patients (post-bronchodilator forced expiratory volume in 1 second/forced vital capacity <0.70) in the early COPD study. Patients with a BEC ≥300cells/μL were classified as the high BEC group. We assessed differences in the clinical characteristics and outcomes between high and low BEC patients. Subgroup analyses were conducted on COPD patients without a history of corticosteroid use or asthma.

RESULTS

Of the 897 COPD patients, 205 (22.9%) had high BEC. At baseline, high BEC patients exhibited a higher proportion of chronic respiratory symptoms, lower lung function, and more severe small airway dysfunction than low BEC patients. Over the 2-year period, high BEC patients experienced a significantly higher risk of acute exacerbations (relative risk: 1.28, 95% confidence interval: 1.09-1.49; P=0.002), even after adjusting for confounders. No significant difference was observed in lung function decline rates. The subgroup analysis yielded consistent results.

CONCLUSIONS

COPD patients with high BEC in a Chinese community exhibited poorer health status, more severe small airway dysfunction, and a higher risk of exacerbations. Future research should explore the pathological mechanisms underlying the poorer prognosis in patients with high BEC.

The association of blood eosinophil counts and FEV1 decline: a cohort study

BACKGROUND

Accelerated lung function decline is characteristic of COPD. However, the association between blood eosinophil counts and lung function decline, accounting for current smoking status, in young individuals without prevalent lung disease is not fully understood.

METHODS

This is a cohort study of 629 784 Korean adults without COPD or a history of asthma at baseline who participated in health screening examinations including spirometry and differential white blood cell counts. We used a linear mixed-effects model to estimate the annual change in forced expiratory volume in 1 s (FEV1) (mL) by baseline blood eosinophil count, adjusting for covariates including smoking status. In addition, we performed a stratified analysis by baseline and time-varying smoking status.

RESULTS

During a mean follow-up of 6.5 years (maximum 17.8 years), the annual change in FEV1 (95% CI) in participants with eosinophil counts <100, 100-199, 200-299, 300-499 and ≥500 cells·µL-1 in the fully adjusted model were -23.3 (-23.9--22.7) mL, -24.3 (-24.9--23.7) mL, -24.8 (-25.5--24.2) mL, -25.5 (-26.2--24.8) mL and -26.8 (-27.7--25.9) mL, respectively. When stratified by smoking status, participants with higher eosinophil count had a faster decline in FEV1 than those with lower eosinophil count in both never- and ever-smokers, which persisted when time-varying smoking status was used.

CONCLUSIONS

Higher blood eosinophil counts were associated with a faster lung function decline among healthy individuals without lung disease, independent of smoking status. The findings suggest that higher blood eosinophil counts contribute to the risk of faster lung function decline, particularly among younger adults without a history of lung disease.

Type-2 inflammation and lung function decline in chronic airway disease in the general population

BACKGROUND

It is unclear if type-2 inflammation is associated with accelerated lung function decline in individuals with asthma and chronic obstructive pulmonary disease (COPD). We tested the hypothesis that type-2 inflammation indicated by elevated blood eosinophils (BE) and fraction of exhaled nitric oxide (FeNO) is associated with accelerated lung function decline in the general population.

METHODS

We included adults from the Copenhagen General Population Study with measurements of BE (N=15 605) and FeNO (N=2583) from a follow-up examination and assessed forced expiratory volume in 1 s (FEV1) decline in the preceding 10 years. Based on pre- and post-bronchodilator lung function, smoking history and asthma at follow-up examination, participants were assigned as not having airway disease, asthma with full reversibility (AR), asthma with persistent obstruction (APO), COPD, and not classifiable airflow limitation (NAL).

RESULTS

FEV1 decline in mL/year increased with 1.0 (95% CI 0.6 to 1.4, p<0.0001) per 100 cells/µL higher BE and with 3.2 (95% CI 2.0 to 4.5, p<0.0001) per 10 ppb higher FeNO. Adjusted FEV1 decline in mL/year was 18 (95% CI 17 to 20) in those with BE<300 cells/µL and FeNO<20 ppb, 22 (19-25) in BE≥300 cells/µL or FeNO≥20 ppb, and 27 (21-33) in those with BE≥300 cells/µL and FeNO≥20 ppb (p for trend<0.0001). Corresponding FEV1 declines were 24 (19-29), 33 (25-40) and 44 (31-56) in AR (0.002), 26 (14-37), 36 (12-60) and 56 (24-89) in APO (0.07), 32 (27-36), 31 (24-38) and 44 (24-65) in COPD (0.46), and 27 (21-33), 35 (26-45), and 37 (25-49) in NAL (0.10), respectively.

CONCLUSIONS

Type-2 inflammation indicated by elevated BE and FeNO is associated with accelerated FEV1 decline in individuals with chronic airway disease in the general population, and this association was most pronounced in an asthma-like phenotype.

Eosinophils and tissue remodeling: Relevance to airway disease

The ability of human tissue to reorganize and restore its existing structure underlies tissue homeostasis in the healthy airways, but in disease can persist without normal resolution, leading to an altered airway structure. Eosinophils play a cardinal role in airway remodeling both in health and disease, driving epithelial homeostasis and extracellular matrix turnover. Physiological consequences associated with eosinophil-driven remodeling include impaired lung function and reduced bronchodilator reversibility in asthma, and obstructed airflow in chronic rhinosinusitis with nasal polyps. Given the contribution of airway remodeling to the development and persistence of symptoms in airways disease, targeting remodeling is an important therapeutic consideration. Indeed, there is early evidence that eosinophil attenuation may reduce remodeling and disease progression in asthma. This review provides an overview of tissue remodeling in both health and airway disease with a particular focus on eosinophilic asthma and chronic rhinosinusitis with nasal polyps, as well as the role of eosinophils in these processes and the implications for therapeutic interventions. Areas for future research are also noted, to help improve our understanding of the homeostatic and pathological roles of eosinophils in tissue remodeling, which should aid the development of targeted and effective treatments for eosinophilic diseases of the airways.

Association between blood eosinophil count and small airway eosinophils in smokers with and without COPD

Introduction

Airway eosinophilic inflammation is a pathological feature in a subgroup of patients with COPD and in some smokers with a high COPD risk. Although blood eosinophil count is used to define eosinophilic COPD, the association between blood eosinophil count and airway eosinophilic inflammation remains controversial. This cross-sectional study tested this association in smokers with and without COPD while considering potential confounders, such as smoking status and comorbidities.

Methods

Lung specimens were obtained from smokers with and without COPD and non-COPD never-smokers undergoing lung lobectomy. Those with any asthma history were excluded. The infiltration of eosinophils into the small airway wall was quantified on histological sections stained with major basic protein (MBP).

Results

The number of airway MBP-positive cells was greater in smokers (n=60) than in never-smokers (n=14). Smokers with and without COPD (n=30 each) exhibited significant associations between blood eosinophil count and airway MBP-positive cells (ρ=0.45 and 0.71). When smokers were divided into the high and low airway MBP groups based on their median value, blood eosinophil count was higher in the high-MBP group, with no difference in age, smoking status, comorbidities, emphysema or coronary artery calcification on computed tomography, and inhaled corticosteroid (ICS) use. The association between greater blood eosinophil count and the high-MBP group was confirmed in multivariable models adjusted for smoking status, airflow limitation and ICS use.

Conclusion

The blood eosinophil count may reflect eosinophilic inflammation in the small airways in smokers with and without COPD.

Association of Pulmonary Function with Osteosarcopenic Obesity in Older Adults Aged over 50 Years

Osteosarcopenic obesity (OSO) is a newly described coexistence of osteopenia/osteoporosis, sarcopenia, and obesity. We examined the association between pulmonary function, OSO, and its composition in adults aged ≥ 50 years. A total of 26,343 participants (8640 men; 17,703 women) were classified into four groups based on the number of abnormal body compositions (osteopenia/osteoporosis, sarcopenia, and obesity): 0 (control), 1+, 2+, and 3+ (OSO) abnormal body compositions. The values of forced volume vital capacity (FVC)%, forced expiratory volume in 1 s (FEV1%), and FEV1/FVC% were significantly decreased by increasing the number of adverse body compositions (p < 0.0001). Although the prevalence of restrictive spirometry pattern (RSP) was positively associated with a higher number of abnormal body composition parameters (p < 0.001), obstructive spirometry pattern (OSP) had no association with adverse body composition. In multivariate analyses, the adjusted odds ratios (ORs) for RSP compared to the control group were 1.36 in 1+, 1.47 in 2+, and 1.64 in 3+ abnormal body compositions (p for trend < 0.001). Multiple abnormal body composition, especially osteosarcopenic obesity, was independently associated with poor lung function showing RSP in older adults over 50 years. The coexistence of these abnormal body compositions may be a predisposing factor for pulmonary function deterioration.

The COPD Assessment Test (CAT) and Depression: A Longitudinal Analysis During the COVID-19 Pandemic

Purpose

Chronic obstructive pulmonary disease (COPD) is multifaceted, with some patients experiencing anxiety and depression. Depression in COPD has been associated with worse total scores for the COPD assessment test (CAT). Also, CAT score worsening has been observed during the COVID-19 pandemic. The relationship between the Center for Epidemiologic Studies Depression Scale (CES-D) score and CAT sub-component scores has not been evaluated. We investigated the relationship between CES-D score and CAT component scores during the COVD-19 pandemic.

Patients and Methods

Sixty-five patients were recruited. Pre-pandemic (baseline) was defined as 23rd March 2019-23rd March 2020, CAT scores and information related to exacerbations were collected via telephone at 8-week intervals between 23rd March 2020-23rd March 2021.

Results

There were no differences in CAT scores pre- compared to during the pandemic (ANOVA p = 0.97). Total CAT scores were higher in patients with symptoms of depression compared to those without both pre- (p < 0.001) and during-pandemic (eg, at 12 months 21.2 versus 12.9, mean difference = 8.3 (95% CI = 2.3-14.2), p = 0.02). Individual CAT component scores showed significantly higher chest tightness, breathlessness, activity limitation, confidence, sleep and energy scores in patients with symptoms of depression at most time points (p < 0.05). Significantly fewer exacerbations were observed during- compared to pre-pandemic (p = 0.04). We observed that COPD patients with symptoms of depression had higher CAT scores both pre- and during the COVID-19 pandemic.

Conclusion

Presence of depressive symptoms was selectively associated with individual component scores. Symptoms of depression may potentially influence total CAT scores.

Metabolically healthy and unhealthy obesity and the development of lung dysfunction

We investigated the association of metabolically healthy (MH) and unhealthy (MU) obesity with incident lung dysfunction. This cohort study included 253,698 Korean lung disease-free adults (mean age, 37.4 years) at baseline. Spirometry-defined lung dysfunction was classified as a restrictive pattern (RP) or obstructive pattern (OP). We defined obesity as BMI ≥ 25 kg/m² and MH as the absence of any metabolic syndrome components with a homeostasis model assessment of insulin resistance < 2.5: otherwise, participants were considered MU. During a median follow-up of 4.9 years, 10,775 RP cases and 7140 OP cases develped. Both MH and MU obesity showed a positive association with incident RP, with a stronger association in the MU than in the MH group (P_interaction = 0.001). Multivariable-adjusted hazard ratios (95% CI) for incident RP comparing obesity to the normal-weight category was 1.15 (1.05-1.25) among the MH group and 1.38 (1.30-1.47) among MU group. Conversely, obesity was inversely associated with OP because of a greater decline in forced vital capacity than forced expiratory volume in 1 s. Both MH and MU obesity were positively associated with RP. However, the associations between obesity, metabolic health, and lung functions might vary depending on the type of lung disease.

Toward a Predict and Prevent Approach in Obstructive Airway Diseases

Asthma and chronic obstructive pulmonary disease are currently diagnosed and treated after the demonstration of variable airflow limitation and symptoms. Under this framework, undiagnosed and unchecked airway inflammation is associated with recurrent acute attacks, airway remodeling, airflow limitation, adverse effects of corticosteroids, and impaired quality of life, ultimately leading to the collection of side effects termed "people remodeling." This one-size-fits-all damage control approach aims to control symptoms and treat exacerbations rather than modify the underlying disease process. The advent of highly effective therapies targeting proximal drivers of airway inflammation calls for a paradigm shift; upstream-acting therapies offer potential to alter the disease course and achieve clinical remission. We propose moving away from downstream firefighting and toward a "predict and prevent" model, measuring inflammation and providing anti-inflammatory therapy early, without waiting for further clinical deterioration. Much in the same way that high blood pressure and cholesterol are used to predict and prevent heart attacks, in asthma, elevated blood eosinophils and/or exhaled nitric oxide can be used to predict and prevent asthma attacks. We also advocate moving research further upstream by identifying patients with subclinical airway inflammation or disease who may be at risk of progressing to airflow limitation and associated morbidities and intervening early to prevent them. In summary, we call for a predict and prevent approach in obstructive airway disease.

Circulating eosinophil levels and lung function decline in stable chronic obstructive pulmonary disease: a retrospective longitudinal study

OBJECTIVE

Whether blood eosinophils (bEOS) in chronic obstructive pulmonary disease (COPD) are associated with disease progression is a topic of debate. We aimed to evaluate whether the differential white blood cell (WBC) count, symptoms and treatment may predict lung function decline and exacerbations in COPD patients.

METHODS

We retrospectively examined stable COPD patients with a minimum follow-up of 3 years at our outpatients' clinic. We collected information about lung volumes (FEV1, FVC), the total and differential WBC count, acute exacerbations of COPD (number in the 12 months before the beginning of the study=AE-COPD-B, and during the follow-up=AE-COPD-F), smoking status and treatment. FEV1 decline and AE-COPD-F were described by using a generalized linear model and a 2-level random intercept negative binomial regression, respectively. The models included eosinophil and neutrophil counts as potential predictors and were adjusted by sex, age, smoking status, AE-COPD-B, treatment with bronchodilators and inhaled corticosteroids (ICS).

RESULTS

Sixty-eight patients were considered, 36 bEOS- (<170 cells/μL, the median value) and 32 bEOS+ (≥170 cells/μL). ∆FEV1 was higher in bEOS+ than bEOS- (34.86 mL/yr vs 4.49 mL/yr, p=0.029). After adjusting for potential confounders, the eosinophil count was positively (β=19.4; CI 95% 2.8, 36.1; p=0.022) and ICS negatively (β=-57.7; CI 95% -91.5,-23.9; p=0.001) associated with lung function decline. bEOS were not found to be associated with the number of AE-COPD-F.

CONCLUSION

In stable COPD patients, a higher level of blood eosinophils (albeit in the normal range) predicts a greater FEV1 decline, while ICS are associated with a slower progression of airflow obstruction.

Clinical relevance of multiple confirmed preserved ratio impaired spirometry cases in adults

BACKGROUND

Preserved ratio impaired spirometry (PRISm) is a common spirometry finding, but its heterogeneous manifestations and frequent transitions to airflow limitation (AFL), chronic obstructive pulmonary disease, or normal spirometry hinder establishing an appropriate management strategy. This study examined whether transition to AFL and baseline comorbidities are more frequent in subjects with definite PRISm (PRISm confirmed on both current and past two spirometry tests) versus incident PRISm (PRISm confirmed only on a current test with past normal spirometry records) than in normal spirometry.

METHODS

Archived medical check-up data of subjects aged ≥40 years (n = 10828) with two past spirometry records, in a Japanese hospital, were cross-sectionally analyzed. Among them, data from those with follow-up spirometry after three years (n = 6467) were used to evaluate transition to AFL. PRISm was defined as forced volume in 1 s (FEV₁)/forced vital capacity ≥0.7 and % predicted FEV₁ < 80%.

RESULTS

Overall PRISm prevalence was 6.5%. In multivariable models adjusted for age, sex, smoking status, and body mass index, definite PRISm (n = 290), but not incident PRISm (n = 183), was associated with elevated hemoglobin A1c and C-reactive protein levels, and higher rates of asthma, hypertension, hyperlipidemia, and diabetes than was consistent normal spirometry (n = 9694). The transition to AFL after three years was more frequent in definite PRISm, but not incident PRISm, than in normal spirometry (adjusted hazard ratio [95% confidence interval] = 6.21 [3.42-10.71] and 1.45 [0.23-4.73], respectively).

CONCLUSIONS

Multiple confirmed PRISm on past and baseline spirometry is closely associated with metabolic syndrome factors, asthma history, and future AFL development.

Blood Eosinophils and Chronic Obstructive Pulmonary Disease: A GOLD Science Committee 2022 Review

COPD is a heterogeneous condition. Some patients benefit from treatment with inhaled corticosteroids (ICS) but this requires a precision medicine approach, based on clinical characteristics (phenotyping) and biological information (endotyping) in order to select patients most likely to benefit. The GOLD 2019 report recommended using exacerbation history combined with blood eosinophil counts (BEC) to identify such patients. Importantly, the relationship between BEC and ICS effects is continuous; no / small effects are observed at lower BEC, with increasing effects at higher BEC. The GOLD 2022 report has added additional evidence and recommendations concerning the use of BEC in COPD in clinical practice. Notably, associations have been demonstrated in COPD patients between higher BEC and increased levels of type-2 inflammation in the lungs. These differences in type-2 inflammation can explain the differential ICS response according to BEC. Additionally, lower BEC are associated with greater presence of proteobacteria, notably haemophilus, and increased bacterial infections and pneumonia risk. These observations support management strategies that use BEC to help identify subgroups with increased ICS response (higher BEC) or increased risk of bacterial infection (lower BEC). Recent studies in younger individuals without COPD have also shown that higher BEC are associated with increased risk of FEV1 decline and the development of COPD. Here we discuss and summarise the GOLD 2022 recommendations concerning the use of BEC as a biomarker that can facilitate a personalised management approach in COPD.

Pathogenesis of chronic obstructive pulmonary disease: understanding the contributions of gene-environment interactions across the lifespan

The traditional view of chronic obstructive pulmonary disease (COPD) as a self-inflicted disease caused by tobacco smoking in genetically susceptible individuals has been challenged by recent research findings. COPD can instead be understood as the potential end result of the accumulation of gene-environment interactions encountered by an individual over the life course. Integration of a time axis in pathogenic models of COPD is necessary because the biological responses to and clinical consequences of different exposures might vary according to both the age of an individual at which a given gene-environment interaction occurs and the cumulative history of previous gene-environment interactions. Future research should aim to understand the effects of dynamic interactions between genes (G) and the environment (E) by integrating information from basic omics (eg, genomics, epigenomics, proteomics) and clinical omics (eg, phenomics, physiomics, radiomics) with exposures (the exposome) over time (T)-an approach that we refer to as GETomics. In the context of this approach, we argue that COPD should be viewed not as a single disease, but as a clinical syndrome characterised by a recognisable pattern of chronic symptoms and structural or functional impairments due to gene-environment interactions across the lifespan that influence normal lung development and ageing.

Low Eosinophil Phenotype Predicts Noninvasive Mechanical Ventilation Use in Patients with Hospitalized Exacerbations of COPD

Rationale

Objective

Methods

Results

Conclusion