Frequent chronic obstructive pulmonary disease exacerbators: how much real, how much fictitious?

COPD patient profiles in primary care. Referral criteria

COPD is a disease with a high prevalence that diminishes the quality of life of many patients. Despite this, there are still high rates of under-diagnosis in Spain, partly due to a lack of recognition of the pathology by patients. In this context, the role played by primary care teams becomes fundamental, as they are one of the first lines of entry into the health system. In this paper we explain the different COPD profiles that may be present, and update the tools for diagnosis and treatment, which, together with an attitude of active suspicion of the disease, can help in the correct management of patients, whether they are undiagnosed or have subsequent complications.

Analysis of Airway Thickening and Serum Cytokines in COPD Patients with Frequent Exacerbations: A Heart of the Matter

Background

Differences in lung function for Chronic Obstructive Pulmonary Disease (COPD) cause bias in the findings when identifying frequent exacerbator phenotype-related causes. The aim of this study was to determine whether computed tomographic (CT) biomarkers and circulating inflammatory biomarkers were associated with the COPD frequent exacerbator phenotype after eliminating the differences in lung function between a frequent exacerbator (FE) group and a non-frequent exacerbator (NFE) group.

Methods

A total of 212 patients with stable COPD were divided into a FE group (n=106) and a NFE group (n=106) according to their exacerbation history. These patients were assessed by spirometry, quantitative CT measurements and blood sample measurements during their stable phase. Univariate and multivariate logistic regression were used to assess the association between airway thickening or serum cytokines and the COPD frequent exacerbator phenotype. Receiver operating characteristic (ROC) curves were calculated for Pi10, WA%, IL-1β and IL-4 to identify frequent exacerbators.

Results

Compared with NFE group, FE group had a greater inner perimeter wall thickness of a 10 mm diameter bronchiole (Pi10), a greater airway wall area percentage (WA%) and higher concentrations of IL-1β and IL-4 (p<0.001). After adjusting for sex, age, BMI, FEV1%pred and smoking pack-years, Pi10, WA%, IL-β and IL-4 were independently associated with a frequent exacerbator phenotype (p<0.001). Additionally, there was an increase in the odds ratio of the frequent exacerbator phenotype with increasing Pi10, WA%, IL-4, and IL-1β (p for trend <0.001). The ROC curve demonstrated that IL-1β had a significantly larger calculated area under the curve (p < 0.05) than Pi10, WA% and IL-4.

Conclusion

Pi10, WA%, IL-4, and IL-1β were independently associated with the frequent exacerbator phenotype among patients with stable COPD, suggesting that chronic airway and systemic inflammation contribute to the frequent exacerbator phenotype.

Trial Registration

This trial was registered in Chinese Clinical Trial Registry (https://www.chictr.org.cn). Its registration number is ChiCTR2000038700, and date of registration is September 29, 2020.

COPD Exacerbation Syndrome: The Spanish Perspective on an Old Dilemma

The definition of exacerbation of COPD as a syndrome, as proposed by the Spanish COPD guidelines (GesEPOC) 2021 update, and the consequences that this implies, have direct implications on patient care. This review analyzes this novel vision of the COPD exacerbation syndrome, its rationale, and its clinical implications, as opposed to the traditional symptoms-based or event-based definitions. An exacerbation conceived as a syndrome provides us with an umbrella term to include a set of diverse alterations, which, either in isolation or more frequently in combination, are clinically expressed in a similar way in patients with COPD. In patients with COPD, this occurs as a consequence of worsening expiratory airflow limitation or the underlying inflammatory process, producing a worsening in symptoms with respect to the baseline situation. This definition therefore assumes a worsening in at least one of the two key physiopathological markers, lung function and inflammation. The main features of this new physiopathological proposal include a syndromic approach with narrower differential diagnosis, the use of several biomarkers, treatable traits to better guide treatment, and a new severity classification. Further research is needed to examine the role of eosinophils in this context, but currently, the early results are promising. The evaluation of severity is key in the multidimensional characterization of exacerbation and the GesEPOC 2021 proposes new approaches and also recommends the use of multidisciplinary scores for severity categorization in patients. Finally, another innovation in the GesEPOC 2021 refers to the recurrence of exacerbations, which has implications for disease prognosis or long-term clinical impact which need to be elucidated in further studies.

Precision medicine in chronic obstructive pulmonary disease

Over the last 20 years, it has become possible to use a precision medicine approach to the management of chronic obstructive pulmonary disease (COPD). Clinical and physiological features as well as a blood biomarker can be used to target treatments to patients most likely to benefit and avoid treatment in patients less likely to benefit. Future advances in a precision medicine approach to COPD will depend on more precise characterization of individual patients, possibly using quantitative imaging, new physiological techniques, novel biomarkers and genetic profiling. Precision medicine has led to significant improvements in the management of COPD and clinicians should use all available information to optimize the treatment of individual patients.

[Translated article] Spanish COPD Guidelines (GesEPOC) 2021 Update. Diagnosis and Treatment of COPD Exacerbation Syndrome

This article details the GesEPOC 2021 recommendations on the diagnosis and treatment of COPD exacerbation syndrome (CES). The guidelines propose a definition-based syndromic approach, a new classification of severity, and the recognition of different treatable traits (TT), representing a new step toward personalized medicine. The evidence is evaluated using GRADE methodology, with the incorporation of 6 new PICO questions. The diagnostic process comprises four stages: 1) establish a diagnosis of CES, 2) assess the severity of the episode, 3) identify the trigger, and 4) address TTs. This diagnostic process differentiates an outpatient approach, that recommends the inclusion of a basic battery of tests, from a more comprehensive hospital approach, that includes the study of different biomarkers and imaging tests. Bronchodilator treatment for immediate relief of symptoms is considered essential for all patients, while the use of antibiotics, systemic corticosteroids, oxygen therapy, and assisted ventilation and the treatment of comorbidities will vary depending on severity and possible TTs. The use of antibiotics will be indicated particularly if sputum color changes, when ventilatory assistance is required, in cases involving pneumonia, and in patients with elevated C-reactive protein (≥ 20 mg/L). Systemic corticosteroids are recommended in CES that requires admission and are suggested in moderate CES. These drugs are more effective in patients with blood eosinophil counts ≥ 300 cells/mm3. Acute-phase non-invasive mechanical ventilation is specified primarily for patients with CES who develop respiratory acidosis despite initial treatment.

AGR3 Regulates Airway Epithelial Junctions in Patients with Frequent Exacerbations of COPD

Background: The mechanisms underlying differences in the susceptibility to chronic obstructive pulmonary disease (COPD) exacerbations between patients are not well understood. Recent studies have shown that the patients with frequent COPD exacerbations is related to specific protein expression in lung tissue. Anterior gradient 3 (AGR3) is expressed in airway epithelial cells in the lung and proteomic analysis revealed that its expression is decreased in patients with frequent COPD exacerbations. Moreover, the loss of epithelial integrity might facilitate trans-epithelial permeability of pathogens in such patients. This study was performed to determine that AGR3 protein play a role in COPD frequency exacerbators. Methods: Human lung tissues were collected from current-smoking patients (Control; n = 15) as well as patients with infrequent COPD exacerbations (IFCOPD; n = 18) and frequent COPD exacerbations (FCOPD; n = 8). While AGR3 protein expression was measured by immunohistochemistry and western blotting, AGR mRNA expression was determined by real time quantitative polymerase chain reaction (RT-qPCR). Furthermore, adherent junctions (AJs) and tight junctions (TJs) protein expression in human lung tissues were measured by immunohistochemistry. The effects of cigarette smoke extract (CSE) on AJ and TJ protein and mRNA expression in BEAS-2B cells were assessed by western blotting and RT-qPCR. In addition, the effect of AGR3 overexpression and knockdown on AJ and TJ protein expression was determined. Results: AGR3 was mainly expressed in the airway epithelium and AGR3-positive products were localized in the cytoplasm. Western blotting and RT-qPCR results showed that AGR3 protein (p = 0.009) and mRNA (p = 0.04) expression in the FCOPD group was significantly lower than that in the IFCOPD group. Moreover, E-cadherin, occludin, and zonula occludens-1 (ZO-1) expression was lower in the FCOPD group than in the IFCOPD group. The protein and mRNA expression of E-cadherin, occludin, and ZO-1 was decreased within 24 h post-CSE exposure. AGR3 overexpression rescued CSE-induced downregulation of E-cadherin, occludin, and ZO-1. Conclusion: Difference in AGR3 expression in the lung tissue might be correlated with increased susceptibility to COPD exacerbation. AGR3 can prevent CSE-induced downregulation of E-cadherin, occludin, and ZO-1 in airway epithelial cells. Loss of AGR3 might promote viral and bacterial infection and induce immune inflammation to increase COPD exacerbation.

Spanish COPD Guidelines (GesEPOC) 2021 Update Diagnosis and Treatment af COPD Exacerbation Syndrome

This article details the GesEPOC 2021 recommendations on the diagnosis and treatment of COPD exacerbation syndrome (CES). The guidelines propose a definition-based syndromic approach, a new classification of severity, and the recognition of different treatable traits (TT), representing a new step toward personalized medicine. The evidence is evaluated using GRADE methodology, with the incorporation of 6 new PICO questions. The diagnostic process comprises four stages: 1) establish a diagnosis of CES, 2) assess the severity of the episode, 3) identify the trigger, and 4) address TTs. This diagnostic process differentiates an outpatient approach, that recommends the inclusion of a basic battery of tests, from a more comprehensive hospital approach, that includes the study of different biomarkers and imaging tests. Bronchodilator treatment for immediate relief of symptoms is considered essential for all patients, while the use of antibiotics, systemic corticosteroids, oxygen therapy, and assisted ventilation and the treatment of comorbidities will vary depending on severity and possible TTs. The use of antibiotics will be indicated particularly if sputum color changes, when ventilatory assistance is required, in cases involving pneumonia, and in patients with elevated C-reactive protein (≥ 20 mg/L). Systemic corticosteroids are recommended in CES that requires admission and are suggested in moderate CES. These drugs are more effective in patients with blood eosinophil counts ≥ 300 cells/mm³. Acute-phase non-invasive mechanical ventilation is specified primarily for patients with CES who develop respiratory acidosis despite initial treatment.

Using Computational Methods to Improve Integrated Disease Management for Asthma and Chronic Obstructive Pulmonary Disease: Protocol for a Secondary Analysis

Background

Asthma and chronic obstructive pulmonary disease (COPD) impose a heavy burden on health care. Approximately one-fourth of patients with asthma and patients with COPD are prone to exacerbations, which can be greatly reduced by preventive care via integrated disease management that has a limited service capacity. To do this well, a predictive model for proneness to exacerbation is required, but no such model exists. It would be suboptimal to build such models using the current model building approach for asthma and COPD, which has 2 gaps due to rarely factoring in temporal features showing early health changes and general directions. First, existing models for other asthma and COPD outcomes rarely use more advanced temporal features, such as the slope of the number of days to albuterol refill, and are inaccurate. Second, existing models seldom show the reason a patient is deemed high risk and the potential interventions to reduce the risk, making already occupied clinicians expend more time on chart review and overlook suitable interventions. Regular automatic explanation methods cannot deal with temporal data and address this issue well.

Objective

To enable more patients with asthma and patients with COPD to obtain suitable and timely care to avoid exacerbations, we aim to implement comprehensible computational methods to accurately predict proneness to exacerbation and recommend customized interventions.

Methods

We will use temporal features to accurately predict proneness to exacerbation, automatically find modifiable temporal risk factors for every high-risk patient, and assess the impact of actionable warnings on clinicians’ decisions to use integrated disease management to prevent proneness to exacerbation.

Results

We have obtained most of the clinical and administrative data of patients with asthma from 3 prominent American health care systems. We are retrieving other clinical and administrative data, mostly of patients with COPD, needed for the study. We intend to complete the study in 6 years.

Conclusions

Our results will help make asthma and COPD care more proactive, effective, and efficient, improving outcomes and saving resources.

International Registered Report Identifier (IRRID)

PRR1-10.2196/27065

Chronic obstructive pulmonary disease phenotypes: imprint on pharmacological and non-pharmacological therapy

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease associated with significant morbidity and mortality. Over the past few years, there has been cumulating interest in describing this heterogeneity and using this information to group patients into different COPD phenotypes. The term phenotype is defined as single or combination of disease attributes that describe differences between individuals with COPD as they relate to clinically meaningful outcomes. It describes also the physical appearance or biochemical characteristics which result from the genotype-environment interaction. Furthermore, it clearly identifies subgroups with a significant impact in the prognosis. Recently, approaches to COPD phenotyping have been significantly enhanced in tandem with developments in understanding the disease’s various pathological, clinical and genetic features. This knowledge inspired the researchers to investigate more tailored therapeutic strategies that could not only give a more potent effect but also help to avoid the traditional therapy’s undesirable side effects. Eventually, it could be said that the phenotypic approach to COPD in the last decade had a huge impact on daily practice and management delivered to COPD patients. In this review, we highlight the impact of pharmacological and non-pharmacological treatment options on COPD outcomes, using a personalized treatment strategy based on different phenotypes.

C-Reactive Protein Concentration in Steady-State Bronchiectasis: Prognostic Value of Future Severe Exacerbations. Data From the Spanish Registry of Bronchiectasis (RIBRON)

BACKGROUND

Both systemic inflammation and exacerbations have been associated with greater severity of bronchiectasis. Our objective was to analyze the prognostic value of the peripheral concentration of C-reactive protein (CRP) for the number and severity of exacerbations in patients with bronchiectasis.

METHODS

Patients from the Spanish Bronchiectasis Registry (RIBRON) with valid data on their CRP value (in a clinically stable phase) and valid data on exacerbations during the first year of follow-up were included. A logistic regression analysis was used to evaluate the prognostic value of the CRP concentration (divided into tertiles) with the presence of at least one severe exacerbation or at least two mild-moderate exacerbations during the first year of follow-up.

RESULTS

802 patients (mean age: 68.1 [11.1 years], 65% female) were included. Of these, 33.8% and 13%, respectively, presented ≥2 mild-moderate exacerbations or at least one severe exacerbation during the first year of follow-up. The mean value of the CRP was 6.5 (17.6mg/L). Patients with a CRP value between 0.4 and 2.7mg/L (second tertile) and ≥2.7mg/L (third tertile) presented a 2.9 (95%CI: 1.4-5.9) and 4.2 (95%CI: 2.2-8.2) times greater probability, respectively, of experiencing a severe exacerbation than those with <0.4mg/L (control group), regardless of bronchiectasis severity or a history of previous exacerbations. However, the CRP value did not present any prognostic value for the number of mild-moderate exacerbations.

CONCLUSIONS

The CRP value was associated with a greater risk of future severe exacerbations but not with mild or moderate exacerbations in patients with steady-state bronchiectasis.

Influence of the Lung Microbiota Dysbiosis in Chronic Obstructive Pulmonary Disease Exacerbations: The Controversial Use of Corticosteroid and Antibiotic Treatments and the Role of Eosinophils as a Disease Marker

Chronic obstructive pulmonary disease (COPD) is a debilitating lung disease associated with loss of lung function, poorer quality of life, co-morbidities, significant mortality, and higher health care costs. Frequent acute exacerbations of COPD are sudden worsening of symptoms, the nature of which is associated with bacterial or viral infections. However, one-third of exacerbations remain of undetermined origin. Although it is largely discussed and controversial, current guidelines recommend treatment of exacerbations with bronchodilators, antibiotics, and systemic corticosteroids; this is despite being associated with limited benefits in term of reducing mortality, side effects and without paying attention to the heterogeneity of these exacerbations. Increasing evidence suggests that the lung microbiota plays an important role in COPD and numerous studies have reported differences in the microbiota between healthy and disease states, as well as between exacerbations and stable COPD, leading to the hypothesis that frequent acute exacerbation is more likely to experience significant changes in lung microbiota composition. These findings will need further examination to explain the causes of lung dysbiosis, namely microbial composition, the host response, including the recruitment of eosinophils, lifestyle, diet, cigarette smoking and the use of antibiotics and corticosteroids. It is now important to assess: 1) Whether alterations in the lung microbiota contribute to disease pathogenesis, especially in exacerbations of unknown origin; 2) The role of eosinophils; and 3) Whether the microbiota of the lung can be manipulated therapeutically to improve COPD exacerbation event and disease progression. In summary, we hypothesize that the alterations of the lung microbiota may explain the undetermined origins of exacerbations and that there is an urgent need to facilitate the design of intervention studies that aim at conserving the lung microbial flora.

Defining the "Frequent Exacerbator" Phenotype in COPD: A Hypothesis-Free Approach

BACKGROUND

The COPD "frequent exacerbator" phenotype is usually defined by at least two treated exacerbations per year and is associated with a huge impact on patient health. However, existence of this phenotype and corresponding thresholds still need to be formally confirmed by statistical methods analyzing exacerbation profiles with no specific a priori hypothesis. The aim of this study was to confirm the existence of the frequent exacerbator phenotype with an innovative unbiased statistical analysis of prospectively recorded exacerbations.

METHODS

Data from patients with COPD from the French cohort in Exacerbations of COPD Patients (EXACO) were analyzed using the KmL method designed to cluster longitudinal data and receiver operating characteristic (ROC) curve analysis to determine the best threshold to allocate patients to identified clusters. Univariate and multivariate analyses were performed to study characteristics associated with different clusters.

RESULTS

Two clusters of patients were identified based on exacerbation frequency over time, with 2.89 exacerbations per year on average in the first cluster (n = 348) and 0.71 on average in the second cluster (n = 116). The best threshold to distinguish these clusters was two moderate to severe exacerbations per year. Frequent exacerbators had more airflow limitation, symptoms, and health-related quality of life impairment. A simple clinical score was derived to help identify patients at risk of exacerbations.

CONCLUSIONS

These analyses confirmed the existence and clinical relevance of a frequent exacerbator subgroup of patients with COPD and the currently used threshold to define this phenotype.

Clinical characteristics of chronic bronchitic, emphysematous and ACOS phenotypes in COPD patients with frequent exacerbations

Purpose

Chronic bronchitis (CB), emphysematous (EM) and asthma–chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS) phenotypes in COPD are well recognized. This study aimed to investigate distinguishing characteristics of these phenotypes in COPD patients with frequent exacerbations (FE).

Patients and methods

A retrospective study was carried out. COPD patients with acute exacerbations were consecutively reviewed from November 2015 to October 2016. Patients were divided into FE and infrequent exacerbations (iFE) subgroups.

Results

A total of 142 eligible COPD subjects were reviewed. In the CB phenotype subgroup, age, body mass index, forced expiratory volume in 1 second (FEV₁) % predicted, COPD assessment test (CAT), modified Medical Research Council breathlessness measurement (mMRC) dyspnea scale, emphysema scores and arterial carbon dioxide pressure (PaCO₂) were significantly different in subjects with FE when compared to those in subjects with iFE of CB. In the EM phenotype subgroup, age, CAT, mMRC scores and history of COPD were different in subjects with FE when compared to those in CB subjects with iFE. Multivariate analysis indicated that FEV₁% predicted (odds ratio [OR] =0.90, P=0.04) and PaCO₂ (OR =1.22, P=0.02) were independent risk factors for FE in COPD with CB phenotype, and CAT (OR =2.601, P=0.001) was the independent risk factor for FE in COPD with EM phenotype. No significant differences in characteristics were observed in ACOS phenotype subgroups with FE or iFE.

Conclusion

In CB or EM phenotypes, COPD patients with FE present several differential clinical characteristics compared to patients with iFE, while the characteristics of ACOS phenotype in patients with FE need more investigation.

The recent advances of phenotypes in acute exacerbations of COPD

Exacerbations of COPD are clinically relevant events with therapeutic and prognostic implications. Yet, significant heterogeneity of clinical presentation and disease progression exists within acute exacerbations of COPD (AECOPD). Currently, different phenotypes have been widely used to describe the characteristics among patients with AECOPD. This has proved to be significant in the treatment and prediction of the outcomes of the disease. In this review of published literature, the phenotypes of AECOPD were classified according to etiology, inflammatory biomarkers, clinical manifestation, comorbidity, the frequency of exacerbations, and so on. This review concentrates on advancements in the use of phenotypes of AECOPD.

Long-acting bronchodilators with or without inhaled corticosteroids and 30-day readmission in patients hospitalized for COPD

BACKGROUND

The ability of a long-acting muscarinic antagonist (LAMA) and long-acting beta 2 agonists (LABAs; long-acting bronchodilators, LABDs) with or without inhaled corticosteroids (ICSs) to reduce early readmission in hospitalized patients with COPD is unknown.

METHODS

We studied a 5% sample of Medicare beneficiaries enrolled in Medicare parts A, B and D and hospitalized for COPD in 2011. We examined prescriptions filled for LABDs with or without ICSs (LABDs±ICSs) within 90 days prior to and 30 days after hospitalization. Primary outcome was the 30-day readmission rate between "users" and "nonusers" of LABDs±ICSs. Propensity score matching and sensitivity analysis were performed by limiting analysis to patients hospitalized for acute exacerbation of COPD (AECOPD). Among 6,066 patients hospitalized for COPD, 3,747 (61.8%) used LABDs±ICSs during the specified period. The "user" and "nonuser" groups had similar rates of all-cause emergency room (ER) visits and readmissions within 30 days of discharge date (22.4% vs 20.7%, P-value 0.11; 18.0% vs 17.8%, P-value 0.85, respectively). However, the "users" had higher rates of COPD-related ER visits (5.3% vs 3.4%, P-value 0.0006), higher adjusted odds ratio (aOR) 1.47 (95% CI, 1.11-1.93) and readmission (7.8% vs 5.0%, P-value <0.0001 and aOR 1.48 [95% CI, 1.18-1.86]) than "nonusers". After propensity score matching, the aOR of COPD-related ER visits was 1.45 (95% CI, 1.07-1.96) and that of readmission was 1.34 (95% CI, 1.04-1.73). The results were similar when restricted to patients hospitalized for AECOPD.

CONCLUSION

Use of LABDs±ICSs did not reduce 30-day readmissions in patients hospitalized for COPD.

Chronic Obstructive Pulmonary Disease

COPD is a common, preventable, and treatable disease characterized by persistent airflow obstruction associated with enhanced inflammation in the airways and the lung in response to noxious particles or gases. Clinical history and pulmonary function testing are necessary for accurate diagnosis. While exposure to tobacco smoke remains a common cause, other etiologies and underlying genetic predisposition play significant roles. Treatment options are numerous and should be individualized based on symptoms and exacerbation frequency.

Prevention of COPD exacerbations: medications and other controversies

Exacerbations have significant impact on the morbidity and mortality of patients with chronic obstructive pulmonary disease. Most guidelines emphasise prevention of exacerbations by treatment with long-acting bronchodilators and/or anti-inflammatory drugs. Whereas most of this treatment is evidence-based, it is clear that patients differ regarding the nature of exacerbations and are likely to benefit differently from different types of treatment. In this short review, we wish to highlight this, suggest a first step in differentiating pharmacological exacerbation prevention and call for more studies in this area. Finally, we wish to highlight that there are perhaps easier ways of achieving similar success in exacerbation prevention using nonpharmacological tools.

The concept of control of COPD in clinical practice

Treatment of chronic obstructive pulmonary disease (COPD) requires a personalized approach according to the clinical characteristics of the patients, the level of severity, and the response to the different therapies. Furthermore, patients with the same level of severity measured by the degree of airflow obstruction or even with multidimensional indices may have very different symptoms and limitations for daily activities. The concept of control has been extensively developed in asthma but has not been defined in COPD. Here, we propose a definition of COPD control based on the concepts of impact and stability. Impact is a cross-sectional concept that can be measured by questionnaires such as the COPD Assessment Test or the Clinical COPD Questionnaire. Alternatively, impact can be assessed by the degree of dyspnea, the use of rescue medication, the level of physical activity, and sputum color. Stability is a longitudinal concept that requires the absence of exacerbations and deterioration in the aforementioned variables or in the COPD Assessment Test or Clinical COPD Questionnaire scores. Control is defined by low impact (adjusted for severity) and stability. The concept of control in COPD can be useful in the decision making regarding an increase or decrease in medication in the stable state.

Chronic Obstructive Pulmonary Disease heterogeneity: challenges for health risk assessment, stratification and management

Background and hypothesis

Heterogeneity in clinical manifestations and disease progression in Chronic Obstructive Pulmonary Disease (COPD) lead to consequences for patient health risk assessment, stratification and management. Implicit with the classical "spill over" hypothesis is that COPD heterogeneity is driven by the pulmonary events of the disease. Alternatively, we hypothesized that COPD heterogeneities result from the interplay of mechanisms governing three conceptually different phenomena: 1) pulmonary disease, 2) systemic effects of COPD and 3) co-morbidity clustering, each of them with their own dynamics.

Objective and method

To explore the potential of a systems analysis of COPD heterogeneity focused on skeletal muscle dysfunction and on co-morbidity clustering aiming at generating predictive modeling with impact on patient management. To this end, strategies combining deterministic modeling and network medicine analyses of the Biobridge dataset were used to investigate the mechanisms of skeletal muscle dysfunction. An independent data driven analysis of co-morbidity clustering examining associated genes and pathways was performed using a large dataset (ICD9-CM data from Medicare, 13 million people). Finally, a targeted network analysis using the outcomes of the two approaches (skeletal muscle dysfunction and co-morbidity clustering) explored shared pathways between these phenomena.

Results

(1) Evidence of abnormal regulation of skeletal muscle bioenergetics and skeletal muscle remodeling showing a significant association with nitroso-redox disequilibrium was observed in COPD; (2) COPD patients presented higher risk for co-morbidity clustering than non-COPD patients increasing with ageing; and, (3) the on-going targeted network analyses suggests shared pathways between skeletal muscle dysfunction and co-morbidity clustering.

Conclusions

The results indicate the high potential of a systems approach to address COPD heterogeneity. Significant knowledge gaps were identified that are relevant to shape strategies aiming at fostering 4P Medicine for patients with COPD.

Prevention of Exacerbations in Chronic Obstructive Pulmonary Disease: Knowns and Unknowns

The 2011 recommendations of the Global initiative for chronic Obstructive Lung Disease (GOLD) constituted a major paradigm shift in COPD management since they set 2 major goals for the assessment and management of patients: (1) the reduction of their current level of symptoms (i.e., treat the patient today); and (2) the reduction of their risk of exacerbations (i.e., prevent them tomorrow). Exacerbations are not only an important clinical endpoint in patients with COPD, but they are also a risk factor themselves for additional adverse outcomes since they have been shown to increase the risk for mortality, to accelerate the decline in pulmonary function, and to decrease health status and quality of life. Despite their importance, many unanswered questions related to exacerbations remain. The purpose of this review is to discuss: (1)knowns and unknowns in our current understanding of exacerbations, (2) what known factors increase their risk, and (3) how to best prevent them.

Frequent exacerbators--a distinct phenotype of severe asthma

BACKGROUND

Exacerbations represent a major source of morbidity and mortality in asthma and are a prominent feature of poorly controlled, difficult-to-treat disease.

OBJECTIVE

The goal of our study was to provide a detailed characterization of the frequent exacerbator phenotype and to identify risk factors associated with frequent and seasonal exacerbations.

METHODS

Ninety-three severe asthmatics (SA) and 76 mild-to-moderate patients (MA) were screened and prospectively followed up for 1 year (NCT00555607). Medical history, baseline clinical data and biomarkers were used to assess risk factors for frequent exacerbations.

RESULTS

During the study, 104 exacerbations were recorded in the SA group and 18 in the MA. Frequent exacerbators were characterized by use of higher doses of inhaled (1700 vs. 800 μg) and oral (6.7 vs. 1.7 mg) glucocorticosteroids, worse asthma control (ACQ score 2.3 vs. 1.4), lower quality of life (SGRQ score 48.5 vs. 33.3), higher sputum eosinophils (25.7% vs. 8.2%) and a more rapid decline in FEV1 /FVC ratio (-0.07 vs. -0.01 ΔFEV1 /FVC, frequent vs. non-frequent, respectively, P < 0.05). Exhaled NO > 45 p.p.b. and a history of smoking were associated with an increased risk of frequent exacerbations (odds ratios: 4.32 and 2.90 respectively).

CONCLUSION AND CLINICAL RELEVANCE

We were able to distinguish and characterize a subphenotype of asthma subjects--frequent exacerbators--who are significantly more prone to exacerbations. Patients with FeNO > 45 p.p.b. and a history of smoking are at increased risk of frequent exacerbations and require careful monitoring in clinical practice.

Should we view chronic obstructive pulmonary disease differently after ECLIPSE? A clinical perspective from the study team

RATIONALE

Chronic obstructive pulmonary disease (COPD) seems to be a heterogeneous disease with a variable course.

OBJECTIVES

We wished to characterize the heterogeneity and variability of COPD longitudinally.

METHODS

In the Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE) study of 2,164 patients with clinically stable COPD, 337 smokers with normal lung function, and 245 never-smokers, we measured a large number of clinical parameters, lung function, exercise tolerance, biomarkers, and amount of emphysema by computed tomography. All three groups were followed for 3 years.

MEASUREMENTS AND MAIN RESULTS

We found a striking heterogeneity among patients with COPD, with poor correlations between FEV1, symptoms, quality of life, functional outcomes, and biomarkers. Presence of systemic inflammation was found in only a limited proportion of patients, and did not relate to baseline characteristics or disease progression, but added prognostic value for predicting mortality. Exacerbations tracked over time and added to the concept of the "frequent exacerbator phenotype." Disease course was very variable, with close to a third of patients not progressing at all. Risk factors for 3-year change in both FEV1 and lung density were assessed. For FEV1 decline, continued smoking and presence of emphysema were the strongest predictors of progression; club cell protein was found to be a potential biomarker for disease activity. For progression of emphysema, the strongest predictors were continued smoking and female sex.

CONCLUSIONS

By following a large, well characterized cohort of patients with COPD over 3 years, we have a clearer picture of a heterogeneous disease with clinically important subtypes ("phenotypes") and a variable and not inherently progressive course. Clinical trial registered with www.clinicaltrials.gov (NCT00292552).

What is in the guidelines about the pharmacological treatment of chronic obstructive pulmonary disease?

With the publication of the new guidelines (The Global Initiative for Chronic Obstructive Lung Disease 2011 and Guía Española de la COPD) on chronic obstructive pulmonary disease (COPD), the pharmacological treatment of this disease has changed substantially. In this article, the evidence supporting the use of pharmacological groups in COPD is summarized and the place of each of these drugs among the new therapeutic strategies is established. Although short-acting bronchodilators have been used as maintenance therapy for COPD for many years, few clinical trials are available on the efficacy and safety of these agents, whose role was defined at the very early stages of treatment. The introduction of long-acting bronchodilators, administered every 12 or 24 h, led to an increase in therapeutic effects and an improvement in both treatment adherence and dosage; therefore, both guidelines consider these drugs as the standard therapy for all types of patients and clinical phenotypes. The combination of long-acting bronchodilators from different families has been established as a new therapeutic approach for patients with persistent symptoms despite an appropriate bronchodilator treatment. Anti-inflammatory therapy with inhaled corticosteroids has been discussed at length, and is considered in the current guidelines as the treatment of choice in patients with a high risk of exacerbations associated with an impaired lung function or previous exacerbations, or presenting with phenotypes that are susceptible to the effect of corticosteroids. Roflumilast is a novel drug with a clearly defined indication. Finally, further evidence about other therapies, such as antibiotics or mucolytics, is emerging that will help define their appropriate use in selected patients. At present, pharmacological management of COPD is being re-evaluated. As long as we are able to apply the new treatment approaches to the clinical reality of our patients we will achieve greater benefits in both the short and the long term with a reduction in potential complications.

The 2011 revision of the global strategy for the diagnosis, management and prevention of COPD (GOLD)--why and what?

INTRODUCTION

The Global Initiative for Chronic Obstructive Lung Disease (GOLD) has published a strategy for diagnosis and for management of chronic obstructive pulmonary disease (COPD) since 2001 and this has formed the basis for numerous national and regional guidelines.

OBJECTIVES

We describe the background for the 2011 revision of the GOLD document.

METHODS

The GOLD document is updated annually and revised every 5 years based on published research as well as an evaluation by an expert panel of how to best formulate and disseminate knowledge on COPD.

RESULTS

The GOLD 2011 revision states that spirometry is required for making a clinical diagnosis of COPD. At the same time, the document has less emphasis on spirometric evaluation of disease severity and launches a combined assessment taking symptoms, spirometry and history of exacerbations into account. This is matched with initial treatment for COPD where smoking cessation, pulmonary rehabilitation and physical activity in general are given high priority followed by pharmacologic treatment guided by the novel assessment scheme. Comorbidities are often present in COPD and the GOLD 2011 revision gives some guidance in how to manage these as well as how to manage COPD in the presence of comorbidities.

CONCLUSION

A more clinically oriented GOLD document will hopefully improve assessment and management of COPD.

Clinical Features according to the Frequency of Acute Exacerbation in COPD

Background

Chronic obstructive pulmonary disease (COPD) is now regarded as a heterogenous disease, with variable phenotypes. Acute exacerbation of COPD is a major event that alters the natural course of disease. The frequency of COPD exacerbation is variable among patients. We analyzed clinical features, according to the frequency of acute exacerbation in COPD.

Methods

Sixty patients, who visited Gyeongsang National University Hospital from March 2010 to October 2010, were enrolled. Patients were divided into two groups, according to their frequency of acute exacerbation. Frequent exacerbator is defined as the patient who has two or more exacerbation per one year. We reviewed patients' medical records and investigated modified Medical Research Council (MMRC) dyspnea scale, smoking history and frequency of acute exacerbation. We also conducted pulmonary function test and 6-minute walking test, calculated body mass index, degree of airway obstruction and dyspnea and exercise capacity (BODE) index and measured CD146 cells in the peripheral blood.

Results

The number of frequent exacerbators and infrequent exacerbators was 20 and 40, respectively. The frequent exacerbator group had more severe airway obstruction (forced expiratory volume in one second [FEV₁], 45% vs. 65.3%, p=0.001; FEV₁/forced vital capacity, 44.3% vs. 50.5%, p=0.046). MMRC dyspnea scale and BODE index were significantly higher in the frequent exacerbator group (1.8 vs. 1.1, p=0.016; 3.9 vs. 2.1, p=0.014, respectively). The fraction of CD146 cells significantly increased in the frequent exacerbator group (2.0 vs. 1.0, p<0.001).

Conclusion

Frequent exacerbator had more severe airway obstruction and higher symptom score and BODE index. However, circulating endothelial cells measured by CD146 needed to be confirmed in the future.

The GOLD initiative 2011: a change of paradigm?

Ten years after the publication of the first GOLD strategy (Global Strategy for the Diagnosis, Management, and Prevention of COPD) for chronic obstructive pulmonary disease (COPD), the new revision published on the GOLD website at the end of 2011 represents a significant change in the diagnostic approach, clinical evaluation and therapeutic treatment of the disease. This revision debates not only the most significant aspects, which remain relatively intact, but also, and in particular, those that have been substantially modified compared with the GOLD revision from 2006.

Early Identification of Exacerbations in Patients With Chronic Obstructive Pulmonary Disease

Frequent exacerbations of chronic obstructive pulmonary disease (COPD) place a considerable burden on the health care system and are a major cause of decreased health-related quality of life, accelerated pulmonary decline, and mortality in individual patients. Primary care physicians are usually the first point of contact for patients experiencing an exacerbation and are therefore best placed to prevent, identify, and treat these events in a timely manner. This review addresses the triggers and risk factors for COPD exacerbations, including the exacerbation-prone phenotype. The prevention, prompt diagnosis, and early appropriate pharmacological/nonpharmacological treatment of COPD exacerbations is important, as early recognition of symptoms (as supported by tools for measuring the illness/wellness experience of COPD patients in primary care) and treatment lead to optimal recovery in these patients. The review also highlights the importance of the urgency in identifying exacerbations and the important role played by primary care physicians in the prevention and postexacerbation management of patients with COPD.

Clinical phenotypes of COPD: identification, definition and implications for guidelines

The term phenotype in the field of COPD is defined as "a single or combination of disease attributes that describe differences between individuals with COPD as they relate to clinically meaningful outcomes". Among all phenotypes described, there are three that are associated with prognosis and especially are associated with a different response to currently available therapies. There phenotypes are: the exacerbator, the overlap COPD-asthma and the emphysema-hyperinflation. The exacerbator is characterised by the presence of, at least, two exacerbations the previous year, and on top of long-acting bronchodilators, may require the use of antiinflammatory drugs. The overlap phenotype presents symptoms of increased variability of airflow and incompletely reversible airflow obstruction. Due to the underlying inflammatory profile, it uses to have a good therapeutic response to inhaled corticosteroids in addition to bronchodilators. Lastly, the emphysema phenotype presents a poor therapeutic response to the existing antiinflammatory drugs and long-acting bronchodilators together with rehabilitation are the treatments of choice. Identifying the peculiarities of the different phenotypes of COPD will allow us to implement a more personalised treatment, in which the characteristics of the patients, together with their severity will be key to choose the best treatment option.

[Treating COPD in chronic patients in a primary-care setting]

The aging of the populations in Western countries entails an increase in chronic diseases, which becomes evident with the triad of age, comorbidities and polymedication. chronic obstructive pulmonary disease represents one of the most important causes of morbidity and mortality, with a prevalence in Spain of 10.2% in the population aged 40 to 80. In recent years, it has come to be defined not only as an obstructive pulmonary disease, but also as a systemic disease. Some aspects stand out in its management: smoking, the main risk factor, even though avoidable, is an important health problem; very important levels of underdiagnosis and little diagnostic accuracy, with inadequate use of spirometry; chronic patient profile; exacerbations that affect survival and cause repeated hospitalizations; mobilization of numerous health-care resources; need to propose integral care (health-care education, rehabilitation, promotion of self-care and patient involvement in decision-making).