Clinical, functional and biochemical changes during recovery from COPD exacerbations

Early detection and prediction of acute exacerbation of chronic obstructive pulmonary disease

Chronic Obstructive Pulmonary Disease (COPD) is characterized by persistent respiratory symptoms and airflow limitation. Acute exacerbation of COPD (AECOPD) is an acute worsening of respiratory symptoms, which needs additional treatment and can result in worsening health status, increasing risks of hospitalization and mortality. Therefore, it is necessary to early recognize and diagnose exacerbations of COPD. This review introduces the updated definition of COPD exacerbations, the current clinical assessment tools, and the current potential biomarkers. The application of mobile health care in COPD management for early identification and diagnosis is also included in this review.

Serum Amyloid A in Stable Patients with Chronic Obstructive Pulmonary Disease Does Not Reflect the Clinical Course of the Disease

Serum amyloid A (SAA) is a good systemic marker of the exacerbations of chronic obstructive pulmonary disease (COPD), but the significance of SAA in stable patients with COPD has not been widely investigated. We aimed to evaluate the SAA level in peripheral blood from stable patients with COPD and to search for correlations between SAA and other inflammatory markers and clinical characteristics of the disease. Serum SAA, IL-6, IL-8, TNF-alpha, basic blood investigations, pulmonary function testing and a 6-min walk test were performed. The correlations between SAA and other inflammatory markers, functional performance and the number of disease exacerbations were evaluated. A total of 100 consecutive patients with COPD were analyzed. No correlations between SAA and inflammatory markers as well as pulmonary function were found. Hierarchical clustering identified two clusters incorporating SAA: one comprised SAA, PaO₂ and FEV₁ and the second was formed of SAA and nine other disease markers. The SAA level was higher in patients with blood eosinophils < 2% when compared to those with blood eosinophils ≥ 2% (41.8 (19.5-69.7) ng/mL vs. 18.9 (1.0-54.5) ng/mL, respectively, p = 0.04). We conclude that, in combination with other important disease features, SAA may be useful for patient evaluation in stable COPD.

Fibrinogen, a Promising Marker to Evaluate Severity and Prognosis of Acute Exacerbation of Chronic Obstructive Pulmonary Disease: A Retrospective Observational Study

Background

Fibrinogen is increasingly being studied as an inflammatory biomarker in chronic obstructive pulmonary disease (COPD), but there are limited data on the role of fibrinogen in assessing the severity of acute exacerbation of COPD (AECOPD). This study aimed to explore whether circulating fibrinogen could be used as a surrogate to measure the severity and predict the prognosis of AECOPD.

Methods

A total of 535 AECOPD patients diagnosed at our center from January 2016 to June 2021 were retrospectively enrolled in this study. The electronic medical record of each patient was retrieved to collect data on baseline characteristics and laboratory parameters, as well as the use of noninvasive positive-pressure ventilation (NPPV) and prognosis. Multiple linear regression analysis was used to identify independent factors associated with circulating fibrinogen values. Receiver-operating characteristic curve and multivariate logistic regression analysis were applied to further verify the use of fibrinogen to predict NPPV failure.

Results

Compared to patients with fibrinogen <4 g/L, patients with increased fibrinogen levels (>4 g/L) tended to have elevated inflammatory response and higher incidence of DVT/PTE, emphysema, pneumonia, and atherosclerosis. In addition, fibrinogen levels in NPPV-failure patients were significantly higher than non-NPPV patients and NPPV-success ones. The presence of emphysema, pneumonia, and history of long-term oxygen therapy and higher CRP levels and leukocyte counts were independent risk factors associated with increased fibrinogen levels in AECOPD. Furthermore, our data indicated that fibrinogen could be considered as a reliable biomarker to predict NPPV failure (AUC, 0.899, 95% CI 0.846–0.952), with an OR of 7.702 (95% CI 2.984–19.875; P<0.001).

Conclusion

The level of circulating fibrinogen can be used to measure severity of AECOPD, and among AECOPD patients managed with NPPV, fibrinogen >3.55 g/L can independently predict NPPV failure.

The Differences in the Levels of Oxidative Status Marker and Soluble CD95 in Patients with Moderate to Severe COPD during an Exacerbation and a Stable Period

Studying the features of changes in markers of oxidative stress (OS) and inflammation indicators in COPD patients depending on the degree of bronchial obstruction is one of the priority directions for improving the prognosis and monitoring of the course of this pathology. We conducted a comparative investigation of changes in markers of OS and apoptosis at the systemic and local levels in patients with moderate to severe COPD during exacerbation and stable phase. 105 patients with COPD aged 46-67 and 21 healthy nonsmoking volunteers comparable in age were examined. COPD patients were divided into four groups: moderate COPD (GOLDII) during the exacerbation (GOLDIIex, $n=25$ ) and in the stable phase (GOLDIIst, $n=27$ ), severe COPD (GOLDIII) during the exacerbation (GOLDIIIex, $n=29$ ), and in the stable phase (GOLDIIIst, $n=24$ ). We studied the levels of such lipid peroxidation (LPO) products as diene conjugates (DC) and Schiff bases (SB) and parameters of induced chemiluminescence (Imax, total light sum-S, Imax/S) in blood serum, as well as sCD95 concentration in blood and exhaled breath condensate (EBC). The relationship between the values of the OS system indicators with sCD95, as well as with the parameters of lung function, was investigated. Multidirectional changes in OS indicator levels in COPD patients depending on the severity of obstructive airway disorders have been established. The maximum values of DC ( $0.26\pm 0.046\text{RU}$ ), Imax ( $0.265\pm 0.19$ RLU), and Imax/S ( $0.13\pm 0.05$ ) were typical for patients with moderate COPD, while the highest SB level ( $5.7\pm 2.3$ RU) was observed in severe COPD during an exacerbation. The exacerbation of the disease was characterized by an increase in DC concentration in both GOLDIIex ( $0.26\pm 0.046$ RU) and GOLDIIIex ( $0.209\pm 0.02$ RU) compared to the stable moderate and severe COPD ( $0.202\pm 0.028$ RU and $0.19\pm 0.03$ RU, respectively, $p<0.05$ ). The established decrease in high values of DC, Imax, Imax/S, and sCD95 and an increase in SB concentration in GOLD III can serve as quantitative indicators of the prognosis of the severity of the disease. The serum concentration of sCD95 in GOLDIIex ( $366.4\pm 70.5$  U/ml) and GOLDIIst ( $361.4\pm 72.8$  U/ml) did not differ from the control group ( $393.7\pm 80.9$  U/ml, $p>0.05$ ). In patients with $\text{FEV}1<49\%$ during the exacerbation and stable phase, the serum levels of Imax/S ( $0.058\pm 0.01$ and $0.062\pm 0.01$ ) and sCD95 ( $318.2\pm 66.3$  U/ml and $321.4\pm 42.5$  U/ml) were lower than the values of healthy volunteers ( $0.08\pm 0.01$ and $393.7\pm 80.9$  U/ml, respectively, $p<0.05$ ). A positive correlation between sCD95 concentration and airway obstruction degree in all examined COPD patients was established. The revealed numerous associations between sCD95 and OS marker levels in GOLDIII indicate a relationship between systemic radical stress and apoptosis processes both in the respiratory tract and the whole body under conditions of severe inflammation. The established correlations between the values of DC, Imax, and sCD95 in the blood serum and the lung function parameters in all studied patients allow us to consider these indicators as additional prognostic indicators of disease intensification. Our work results help clarify the participation and detail of FRO and apoptosis processes in developing pathophysiological features in moderate to severe COPD in different periods and, accordingly, improve the efficiency of diagnosis and treatment of the disease.

Factors affecting brain structure in smoking-related diseases: Chronic Obstructive Pulmonary Disease (COPD) and coronary artery disease

Background

Changes in brain structure and cognitive decline occur in Chronic Obstructive Pulmonary Disease (COPD). They also occur with smoking and coronary artery disease (CAD), but it is unclear whether a common mechanism is responsible.

Methods

Brain MRI markers of brain structure were tested for association with disease markers in other organs. Where possible, principal component analysis (PCA) was used to group markers within organ systems into composite markers. Univariate relationships between brain structure and the disease markers were explored using hierarchical regression and then entered into multivariable regression models.

Results

100 participants were studied (53 COPD, 47 CAD). PCA identified two brain components: brain tissue volumes and white matter microstructure, and six components from other organ systems: respiratory function, plasma lipids, blood pressure, glucose dysregulation, retinal vessel calibre and retinal vessel tortuosity. Several markers could not be grouped into components and were analysed as single variables, these included brain white matter hyperintense lesion (WMH) volume. Multivariable regression models showed that less well organised white matter microstructure was associated with lower respiratory function (p = 0.028); WMH volume was associated with higher blood pressure (p = 0.036) and higher C-Reactive Protein (p = 0.011) and lower brain tissue volume was associated with lower cerebral blood flow (p<0.001) and higher blood pressure (p = 0.001). Smoking history was not an independent correlate of any brain marker.

Conclusions

Measures of brain structure were associated with a range of markers of disease, some of which appeared to be common to both COPD and CAD. No single common pathway was identified, but the findings suggest that brain changes associated with smoking-related diseases may be due to vascular, respiratory, and inflammatory changes.

Hypercoagulable State in COPD-A Comprehensive Literature Review

Chronic Obstructive Pulmonary Disease (COPD) is a chronic inflammatory disease with multisystemic manifestations. Studies either held on stable disease patients or during exacerbations have demonstrated that COPD is strongly related to venous thromboembolism and cardiovascular events. The aim of the present review of the literature was to provide an in-depth overview regarding the alterations of coagulation factors and prothrombotic changes generated in patients with stable COPD and during COPD exacerbations.

Lung function decline is associated with serum uric acid in Korean health screening individuals

We performed a retrospective cohort study of 19,237 individuals who underwent at least three health screenings with follow-up periods of over 5 years to find a routinely checked serum marker that predicts lung function decline. Using linear regression models to analyze associations between the rate of decline in the forced expiratory volume in 1 s (FEV1) and the level of 10 serum markers (calcium, phosphorus, uric acid, total cholesterol, total protein, total bilirubin, alkaline phosphatase, aspartate aminotransferase, creatinine, and C-reactive protein) measured at two different times (at the first and third health screenings), we found that an increased uric acid level was significantly associated with an accelerated FEV1 decline (P = 0.0014 and P = 0.037, respectively) and reduced FEV1 predicted % (P = 0.0074 and P = 8.64 × 10^–7, respectively) at both visits only in non-smoking individuals. In addition, we confirmed that accelerated forced vital capacity (FVC) and FEV1/FVC ratio declines were observed in non-smoking individuals with increased serum uric acid levels using linear mixed models. The serum uric acid level thus potentially predicts an acceleration in lung function decline in a non-smoking general population.

Oxidative Stress Biomarkers in Chronic Obstructive Pulmonary Disease Exacerbations: A Systematic Review

Background: Chronic Obstructive Pulmonary Disease (COPD) is a progressive disease characterized by a not fully reversible airflow limitation associated with an abnormal inflammatory response. Exacerbations of COPD are of major importance in the acceleration of disease progression, in healthcare costs, and negatively affect the patient’s quality of life. Exacerbations are characterized by a further increase in the airway inflammation likely driven by oxidative stress. In order to deepen the knowledge about this topic, several studies have focused on oxidative stress biomarkers levels. This review summarizes the literature findings about oxidative stress biomarkers in exacerbated COPD patients compared to ones in the stable state. Methods: a systematic search in electronic databases Pubmed, Web of Science, Scopus and Google Scholar from inception to January 2021, was conducted using the terms: “oxidative stress”, “chronic obstructive pulmonary disease” or “COPD”, “exacerbation”. Results: 23 studies were selected for the systematic review. They showed the presence of an imbalance between oxidant and antioxidant molecules in favor of the former in exacerbation of COPD. Conclusions: future studies using standardized methods in better characterized population are needed. However, this review suggests that targeting oxidative stress could be useful in monitoring the disease progression in COPD patients and especially in those more susceptible to exacerbations.

Systemic Galectin-3 in Smokers with Chronic Obstructive Pulmonary Disease and Chronic Bronchitis: The Impact of Exacerbations

PURPOSE

The carbohydrate-binding protein Galectin-3 is increased in several inflammatory diseases and has recently been forwarded as a systemic biomarker in chronic obstructive pulmonary disease (COPD). In this longitudinal study, we characterized the level of systemic Galectin-3 using blood from smokers with a history of COPD and chronic bronchitis (COPD-CB), during stable clinical conditions and exacerbations.

PATIENTS AND METHODS

The study population comprised 56 long-term smokers with COPD-CB, 10 long-term smokers without lung disease (LTS) and 10 clinically healthy never-smokers (HNS). Blood samples were analyzed for levels of Galectin-3, leukocyte populations and C-reactive protein (CRP). In addition, sputum samples from the COPD-CB group were analyzed for bacterial growth.

RESULTS

When comparing stable clinical conditions and exacerbations in the COPD-CB group, we found that the level of Galectin-3, just like that of CRP, leukocytes and neutrophils, respectively, was increased during exacerbations. However, this exacerbation-associated increase of Galectin-3 was modest. During stable clinical conditions of COPD-CB, the level of Galectin-3 was not elevated in comparison with HNS or LTS. Nor did this level of Galectin-3 distinguish patients that remained in a clinically stable condition throughout the study to those that developed an exacerbation. In addition, neither during stable clinical conditions nor during exacerbations, did the presence of bacterial growth in sputum alter Galectin-3 levels. In contrast to Galectin-3, the level of CRP, leukocytes and neutrophils, respectively, were increased during clinical stable conditions in the COPD-CB group compared with the other groups and were further enhanced during exacerbations.

CONCLUSION

Systemic Galectin-3 is increased in a reproducible but modest manner during exacerbations in smokers with COPD-CB. During stable clinical conditions, the level of systemic Galectin-3 does not distinguish patients that remain clinically stable from those that develop exacerbations. This makes it less likely that systemic Galectin-3 may become a clinically useful biomarker in the current setting.

Changes in symptoms and health-related quality of life in patients with exacerbated chronic obstructive pulmonary disease

AIMS

To describe changes in symptoms and identify distinct subgroups of symptoms, to determine whether the sample's characteristics predicted changes in symptoms, and to examine how changes in symptoms predicted changes in health-related quality of life (HRQOL) over 6 months in patients with exacerbated chronic obstructive pulmonary disease (COPD).

BACKGROUND

Different patterns of changes in symptoms and their relationship to changes in HRQOL in patients with exacerbated COPD over long periods of time have been understudied.

METHODS

In this longitudinal study, participants with COPD (N = 42) had been admitted to a medical ward or had visited a pulmonary medicine clinic for treatment of exacerbation. Descriptive and inferential statistics were used to analyze data from questionnaires that assessed symptoms and HRQOL at baseline, daily symptoms over 6 months, and HRQOL at 6 months after exacerbation.

RESULTS

Not all participants experienced improved symptoms over time. Two sets of subgroups (improving &worsening; constantly better &constantly worse) emerged, based on 6-month changes in symptoms. Sample characteristics of the improving and worsening subgroups were similar, whereas usual dyspnea and HRQOL were significantly different in the constantly better and constantly worse subgroups. Little change in HRQOL was found in the total sample, but HRQOL deteriorated in the worsening subgroup, although deterioration was not meaningful. Changes in symptoms significantly predicted changes in HRQOL over 6 months.

CONCLUSION

Assessing patients' symptoms after exacerbations of COPD may enable health care providers to identify those at risk of future exacerbations and poorer HRQOL.0.

Exacerbations of Chronic Obstructive Pulmonary Disease and Cardiac Events. A Post Hoc Cohort Analysis from the SUMMIT Randomized Clinical Trial

RATIONALE

Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are common, associated with acute inflammation, and may increase subsequent cardiovascular disease (CVD) risk.

OBJECTIVES

Determine whether AECOPD events are associated with increased risk of subsequent CVD.

METHODS

We performed a secondary cohort analysis of the SUMMIT (Study to Understand Mortality and Morbidity) trial, a convenience sample of current/former smokers with moderate COPD from 1,368 centers in 43 countries. All had CVD or increased CVD risk. AECOPD was defined as an increase in respiratory symptoms requiring treatment with antibiotics, systemic corticosteroids, and/or hospitalization. CVD events were a composite outcome of cardiovascular death, myocardial infarction, stroke, unstable angina, and transient ischemic attack. All CVD events were adjudicated. Cox proportional hazards models compared the hazard for a CVD event before AECOPD versus after AECOPD.

MEASUREMENTS AND MAIN RESULTS

Among 16,485 participants in SUMMIT, 4,704 participants had at least one AECOPD and 688 had at least one CVD event. The hazard ratio (HR) for CVD events after AECOPD was increased, particularly in the first 30 days after AECOPD (HR, 3.8; 95% confidence interval, 2.7-5.5) and was elevated up to 1 year after AECOPD. The 30-day HR after hospitalized AECOPD was more than twofold greater (HR, 9.9; 95% confidence interval, 6.6-14.9).

CONCLUSIONS

In patients with COPD with CVD or risk factors for CVD, exacerbations confer an increased risk of subsequent CVD events, especially in hospitalized patients and within the first 30 days after exacerbation. Patients and clinicians should have heightened vigilance for early CVD events after AECOPD. Clinical trial registered with www.clinicaltrials.gov (NCT 01313676).

Increased risk of major adverse cardiac events following the onset of acute exacerbations of COPD

BACKGROUND AND OBJECTIVE

Acute exacerbations in chronic obstructive pulmonary disease (COPD) may trigger major adverse cardiac events (MACE). We aimed to determine whether the risk of having MACE was transiently increased following the onset of an acute COPD exacerbation.

METHODS

We conducted a nationwide, register-based study from 1997 to 2014 comprising individuals with an acute COPD exacerbation followed by a MACE (acute myocardial infarction (MI), stroke or cardiovascular death). Using the case-crossover design, we estimated odds ratios (OR) for the association between acute exacerbations of COPD and MACE as well as for single outcomes (acute MI, stroke and cardiovascular death), different levels of severity of exacerbations and within patient subgroups.

RESULTS

We identified 118 807 cases with a MACE preceded by an exacerbation. Overall, the risk of MACE increased almost fourfold following the onset of an acute exacerbation compared to periods without exacerbations in the same individuals (OR: 3.70; 95% CI: 3.60-3.80). The associations were consistent for single outcomes (acute MI, OR: 3.57; cardiovascular death, OR: 4.33; and stroke, OR: 2.78) and particularly strong associations were demonstrated for severe exacerbations (OR: 5.92) and the oldest individuals (OR: 4.18).

CONCLUSION

The risk of MACE increased substantially following the onset of an acute exacerbation. This highlights that prevention of cardiac events is an important goal in the management of COPD. Attention should be paid to detecting cardiovascular disease following acute COPD exacerbations.

Mean platelet volume as a predictor of pulmonary hypertension in patients with stable COPD

Background: Pulmonary hypertension (PH) is one of the most common complications developed during the course of chronic obstructive pulmonary disease (COPD). Platelet activation plays an important role in its pathophysiology, and mean platelet volume (MPV) is considered a respectable index of platelet activation. The aim of this work is to assess the ability of MPV in predicting PH secondary to COPD as well as its severity.

Methods: A cross-sectional study was conducted on 228 stable COPD patients. CBC, echocardiography, and pulmonary function tests were performed.

Results: The prevalence of PH in stable COPD patients was high (63%), and the majority of patients had a mild degree (33%). There was no significant association between PH presence with different COPD grade, but, in very severe COPD, severe PH was significantly presented. MPV in COPD patients with PH was significantly higher than those without (9.02±1.14 vs 7.11±0.98, P<0.001). Moreover, a significant statistical rising of MPV with increased severity of PH. Multivariate regression analysis of predictors of PH demonstrated that; MPV is a real predictor of PH in such patients. The likelihood probability of PH increased up to 7-times with increasing one unit of MPV; (OR=6.7). A cut-off value of MPV >7.25 had 96% sensitivity and 76% specificity in predicting PH.

Conclusion: MPV was higher in COPD patients with PH and positively correlated with PH severity. If the data are to be confirmed, MPV may be taken into consideration in decision-making and management of COPD patients.

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

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

Enhancing our understanding of the time course of acute exacerbations of COPD managed on an outpatient basis

Purpose

Acute exacerbations of COPD (AECOPD) are associated with pulmonary/systemic changes; however, quantification of those changes during AECOPD managed on an outpatient basis and factors influencing recovery are lacking. This study aimed to characterize patients’ changes during AECOPD and identify factors influencing their recovery.

Methods

Body mass index, the modified British Medical Research Council questionnaire, number of exacerbations in the previous year, and the Charlson comorbidity index (independent variables) were collected within 24–48 hours of hospital presentation (T0). Peripheral oxygen saturation (SpO₂), forced expiratory volume in one second, percentage predicted (FEV₁% predicted), maximum inspiratory pressure, quadriceps muscle strength, 5 times sit-to-stand, and COPD assessment test (CAT) (dependent variables) were collected at T0 and approximately at days 8 (T1), 15 (T2), and 45 (T3) after T0.

Results

A total of 44 outpatients with AECOPD (31♂; 68.2±9.1 years; 51.1±20.3 FEV₁% predicted) were enrolled. All variables improved overtime (P<0.05); however, at day 8, only SpO₂ and CAT (P≤0.001) showed significant improvements. Changes in FEV₁% predicted and SpO₂ were not influenced by any independent measure, while changes in other outcome measures were influenced by at least one of the independent measures. Independently of the time of data collection, being underweight or overweight and having increased dyspnea, previous exacerbations, and severe comorbidities negatively affected patients’ outcomes.

Conclusion

FEV₁% predicted and SpO₂ were not influenced by any independent measure and, thus, seem to be robust measures to follow-up outpatients with AECOPD. No single indicator was able to predict patients’ recovery for all measures; thus, a comprehensive assessment at the onset of the AECOPD is required to personalize interventions.

Comparison of patient-reported outcomes during acute exacerbations of chronic obstructive pulmonary disease

Introduction

The aim of this study was to investigate which patient-reported outcome measure was the best during the recovery phase from severe exacerbation of chronic obstructive pulmonary disease (COPD).

Methods

The Exacerbations of Chronic Pulmonary Disease Tool (EXACT), the COPD Assessment Test (CAT), the St George’s Respiratory Questionnaire (SGRQ), the Dyspnoea-12 (D-12) and the Hyland Scale (global scale) were recorded every week for the first month and at 2 and 3 months in 33 hospitalised subjects with acute exacerbation of COPD (AECOPD).

Results

On the day of admission (day 1), the internal consistency of the EXACT total score was high (Cronbach’s alpha coefficient=0.89). The EXACT total, CAT, SGRQ total and Hyland Scale scores obtained on day 1 appeared to be normally distributed. Neither floor nor ceiling effects were observed for the EXACT total and SGRQ total scores. The EXACT total score improved from 50.5±12.4 to 32.5±14.3, and the CAT score also improved from 24.4±8.5 to 13.5±8.4 during the first 2 weeks, and the effect sizes (ES) of the EXACT total and CAT score were −1.40 and −1.36, respectively. The SGRQ, Hyland Scale and D-12 were less responsive, with ES of −0.59, 0.96 and −0.90, respectively.

Discussion

The EXACT total and CAT scores are shown to be more responsive measures during the recovery phase from severe exacerbation. Considering the conceptual framework, it is recommended that the EXACT total score may be the best measure during the recovery phase from AECOPD. The reasons for the outstanding responsiveness of the CAT are still unknown.

Dynamic Characteristics of Sequential Acute Exacerbations and Risk Windows in AECOPD Rats Induced by Cigarette-Smoke and Exposure to Klebsiella pneumoniae

The risk-window (RW) of chronic obstructive pulmonary disease (COPD) is a period after an acute exacerbation (AE) but before the following stable phase, in which exacerbations are easy to relapse. We established a sequential COPD-AE-RW rat model by cigarette-smoke and bacterial exposures in the first 8 weeks, and was challenged with Klebsiella pneumonia to mimic an AE on Day 1 of week 9, and found that body temperature, white blood cell, neutrophils, serum amyloid A (SAA) and C-reactive protein (CRP) increased in AECOPD rats 24 h after challenge, and declined in 3-6 d, while lung function declined in 48 h, and recovered in 7-16 d. When sacrificed, pulmonary forced expiratory volume (FEV)100 and FEV300 decreased, while elevated bronchoalveolar lavage fluid (BALF) neutrophils and marked airway inflammation, remodeling and emphysema were observed. Sequential COPD-AE-RW rat model was established successfully and AE phase lasts for approximately 5-7 d, followed by a 10-d around risk-window.

Association of Serum Galectin-3 with the Acute Exacerbation of Chronic Obstructive Pulmonary Disease

BACKGROUND Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) aggravates the overall severity in COPD patients, resulting in severe morbidity and mortality. However, there are no objective biomarkers currently available to predict the development of AECOPD. Several studies have indicated that galectin-3 (Gal-3) is involved in diseases characterized by excessive inflammatory response and fibrosis. The objective of this study was to examine the dynamic changes of Gal-3 in acute exacerbation and convalescence phases of COPD. MATERIAL AND METHODS Serum levels of Gal-3, high sensitivity C-reactive protein (hsCRP), and prohormone of brain natriuretic peptide (pro-BNP) were determined using multiplex enzyme-linked immunosorbent assay kits. Serum levels of Gal-3 in 44 patients with COPD were further analyzed and correlated with the parameters of lung function and the biomarkers of systemic inflammation. RESULTS The mean level of serum Gal-3 was significantly higher in acute exacerbation of COPD compared with the level in COPD convalescence phase (32.10±9.83 versus 29.02±8.68 ng/mL, p<0.01). Serum levels of Gal-3 positively correlated with hsCRP (r=0.354, p=0.018 for total patients) and pro-BNP (r=0.319, p=0.035 for total patients) in AECOPD. In addition, the level of Gal-3 was the highest in the current smoker group, and the lowest in the never-smoker group in either the acute exacerbation phase (33.91±3.55 versus 29.12±11.73 ng/mL, p=0.036) or the convalescence phase (30.94±3.40 versus 27.76±9.68 ng/mL, p=0.045) of COPD. CONCLUSIONS Our results indicated that serum Gal-3 is increased in AECOPD patients, which is also positively associated with systemic inflammation and smoking in patients with COPD, suggesting that Gal-3 might be a valuable biomarker for AECOPD.

Serum Cystatin C as an Inflammatory Marker in Exacerbated and Convalescent COPD Patients

Chronic obstructive pulmonary disease (COPD) is a common chronic inflammatory disease with high morbidity and mortality rates. Cystatin C (Cys C) is a sensitive indicator for various chronic inflammatory diseases. In this study, we aimed to evaluate the role of Cys C in COPD patients comparing with the other well-known inflammatory markers. Ninety patients with acute exacerbated COPD were studied and were reassessed when convalescent. Ninety controls were matched for age, gender, body mass index, smoking index, and comorbidity. Serum Cys C was significantly increased in convalescent COPD patients compared with healthy controls and further increased in COPD patients with an acute exacerbation. Serum Cys C was positively correlated with hsCRP both in the exacerbation and convalescence periods of COPD and negatively correlated with FEV1% predicted and FEV1/FVC in the convalescent COPD patients. In conclusion, serum Cys C is a positive acute-phase reactant in COPD patients and might indicate systemic inflammation during the progression of COPD.

Evaluation of plasma leptin, tumor necrosis factor-α, and prealbumin as prognostic biomarkers during clinical recovery from acute exacerbations of chronic obstructive pulmonary disease

BACKGROUND

Inflammatory and nutritional biomarkers have an important bearing on outcomes of acute exacerbations of chronic obstructive pulmonary disease (AECOPD), but the temporal profile of these compounds during an acute episode is unclear.

PATIENTS AND METHODS

Plasma leptin, prealbumin, and tumor necrosis factor-alpha (TNF-α) were estimated at baseline and before hospital discharge in patients with AECOPD.

RESULTS

A total of 82 patients were evaluated (66 males; mean (standard deviation) age, 61.6 (10.1) years. Of these, 74 subjects (90.2%) were current or former smokers, with median (range) pack-years of 15 (0-96), duration of COPD of 8 years (range, 2-25 years) and duration of current symptoms being 5 days (range, 1-30 days). Majority (41.5%) had type I (severe) exacerbation. During the current episode, 46 patients (58.9%) required mechanical ventilation for a median of 6 days (range, 1-34). The median duration of hospital stay was 13 days, (range, 1-110). At discharge, significant reduction was observed in dyspnea, total leukocyte count, erythrocyte sedimentation rate (ESR), partial pressure of carbon dioxide, hemoglobin, urea, creatinine, potassium, aspartate transferase, and TNF-α levels compared to baseline, whereas arterial pH, PO₂, serum albumin, prealbumin, and leptin significantly improved. No difference was seen in leptin, prealbumin, and TNF-α between patients with mild/moderate and severe exacerbation, or between patients who required or did not require mechanical ventilation. Change in leptin correlated with body mass index and change in ESR; no associations were observed between leptin, prealbumin, and TNF-α with other clinico-laboratory variables.

CONCLUSION

Plasma levels of novel inflammatory and nutritional biomarkers, i.e., leptin, TNF-α, and prealbumin are altered in AECOPD episodes and lag behind other parameters during recovery. These biomarkers are not reliable predictors of clinical outcomes in these patients.

Endocan and the respiratory system: a review

Endocan, formerly called endothelial cell-specific molecule 1, is an endothelial cell-associated proteoglycan that is preferentially expressed by renal and pulmonary endothelium. It is upregulated by proangiogenic molecules as well as by pro-inflammatory cytokines, and since it reflects endothelial activation and dysfunction, it is regarded as a novel tissue and blood-based relevant biomarker. As such, it is increasingly being researched and evaluated in a wide spectrum of healthy and disease pathophysiological processes. Here, we review the present scientific knowledge on endocan, with emphasis on the evidence that underlines its possible clinical value as a prognostic marker in several malignant, inflammatory and obstructive disorders of the respiratory system.

Sequential Treatments with Tongsai and Bufei Yishen Granules Reduce Inflammation and Improve Pulmonary Function in Acute Exacerbation-Risk Window of Chronic Obstructive Pulmonary Disease in Rats

Background. Sequential treatments of Chinese medicines for acute exacerbation of chronic obstructive pulmonary disease (AECOPD) risk window (RW) have benefits for preventing reoccurrences of AEs; however, the effects on pulmonary function, pulmonary, and systemic inflammatory biomarkers remain unclear. Methods. Cigarette-smoke/bacterial infections induced rats were randomized into Control, COPD, AECOPD, Tongsai Granule/normal saline (TSG/NS), moxifloxacin + salbutamol/NS (MXF+STL/NS), TSG/Bufei Yishen Granule (BYG), MXF+STL/STL, and TSG+MXF+STL/BYG+STL groups and given corresponding medicine(s) in AE- and/or RW phase. Body temperature, pulmonary function, blood cytology, serum amyloid A (SAA) and C-reactive protein (CRP), pulmonary histomorphology and myeloperoxidase (MPO), polymorphonuclear (PMN) elastase, interleukins IL-1β, IL-6, and IL-10, and tumor necrosis factor- (TNF-) α expressions were determined. Results. Body temperature, inflammatory cells and cytokines, SAA, CRP, and pulmonary impairment were higher in AECOPD rats than stable COPD, while pulmonary function declined and recovered to COPD level in 14–18 days. All biomarkers were improved in treated groups with shorter recovery times of 4–10 days, especially in TSG+MXF+STL/BYG+STL group. Conclusion. Sequential treatments with Tongsai and Bufei Yishen Granules, during AECOPD-RW periods, can reduce inflammatory response and improve pulmonary function and shorten the recovery courses of AEs, especially the integrated Chinese and Western medicines.

A Systematic Review of Diagnostic Biomarkers of COPD Exacerbation

The aims of this systematic review were to determine which blood-based molecules have been evaluated as possible biomarkers to diagnose chronic obstructive pulmonary disease (COPD) exacerbations (AECOPD) and to ascertain the quality of these biomarker publications. Patients of interest were those that have been diagnosed with COPD. MEDLINE, EMBASE, and CINAHL databases were searched systematically through February 2015 for publications relating to AECOPD diagnostic biomarkers. We used a modified guideline for the REporting of tumor MARKer Studies (mREMARK) to assess study quality. Additional components of quality included the reporting of findings in a replication cohort and the use of receiver-operating characteristics area-under-the curve statistics in evaluating performance. 59 studies were included, in which the most studied biomarkers were C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α). CRP showed consistent elevations in AECOPD compared to control subjects, while IL-6 and TNF-α had variable statistical significance and results. mREMARK scores ranged from 6 to 18 (median score of 13). 12 articles reported ROC analyses and only one study employed a replication cohort to confirm biomarker performance. Studies of AECOPD diagnostic biomarkers remain inconsistent in their reporting, with few studies employing ROC analyses and even fewer demonstrating replication in independent cohorts.

Oxidative and Nitrosative Stress and Histone Deacetylase-2 Activity in Exacerbations of COPD

BACKGROUND

Respiratory virus infections are commonly associated with COPD exacerbations, but little is known about the mechanisms linking virus infection to exacerbations. Pathogenic mechanisms in stable COPD include oxidative and nitrosative stress and reduced activity of histone deacetylase-2 (HDAC2), but their roles in COPD exacerbations is unknown. We investigated oxidative and nitrosative stress (O&NS) and HDAC2 in COPD exacerbations using experimental rhinovirus infection.

METHODS

Nine subjects with COPD (Global Initiative for Chronic Obstructive Lung Disease stage II), 10 smokers, and 11 nonsmokers were successfully infected with rhinovirus. Markers of O&NS-associated cellular damage, and inflammatory mediators and proteases were measured in sputum, and HDAC2 activity was measured in sputum and bronchoalveolar macrophages. In an in vitro model, monocyte-derived THP-1 cells were infected with rhinovirus and nitrosylation and activity of HDAC2 was measured.

RESULTS

Rhinovirus infection induced significant increases in airways inflammation and markers of O&NS in subjects with COPD. O&NS markers correlated with virus load and inflammatory markers. Macrophage HDAC2 activity was reduced during exacerbation and correlated inversely with virus load, inflammatory markers, and nitrosative stress. Sputum macrophage HDAC2 activity pre-infection was inversely associated with sputum virus load and inflammatory markers during exacerbation. Rhinovirus infection of monocytes induced nitrosylation of HDAC2 and reduced HDAC2 activity; inhibition of O&NS inhibited rhinovirus-induced inflammatory cytokines.

CONCLUSIONS

O&NS, airways inflammation, and impaired HDAC2 may be important mechanisms of virus-induced COPD exacerbations. Therapies targeting these mechanisms offer potential new treatments for COPD exacerbations.

Correlation between decrease of CRP and resolution of airway inflammatory response, improvement of health status, and clinical outcomes during severe acute exacerbation of chronic obstructive pulmonary disease

Circulating C-reactive protein (CRP) plays an important role in mediating extra-pulmonary complications of chronic obstructive pulmonary disease (COPD). The aim of this study was to investigate the relationship between changes in high sensitivity (hs)-CRP levels and the resolution of airway inflammatory markers and clinical health status during the recovery period after an acute exacerbation of COPD (AECOPD). Consecutive patients hospitalized for AECOPD were recruited. Serum hs-CRP, airway inflammatory markers, and COPD Assessment Test (CAT) score were evaluated at admission prior to treatment and at days 4, 7, and 14. Adverse outcomes were recorded. The relationship between changes in airway inflammatory markers, CAT score, and hs-CRP during the recovery period was studied. A total of 135 patients were enrolled. Serum hs-CRP levels at admission of patients with adverse outcomes were marginally higher than those without an adverse outcome (7.6 [4.8, 16.7] vs. 6.6 [4.7, 9.3], p = 0.061). Compared with patients without cardiovascular complications, patients with cardiovascular complications had higher serum hs-CRP levels at admission (11.6 [6.7, 16.7] vs. 6.6 [4.4, 10.0], p = 0.001). Sputum neutrophils were positively correlated to hs-CRP at admission (r = 0.474, p < 0.001). A decreasing hs-CRP level was positively related to decreasing sputum neutrophils at day 4 and 7 (r = 0.455, p < 0.001; r = 0.504, p < 0.001, respectively). Significant correlations between decreasing hs-CRP and CAT at all time-points were noted. Hs-CRP may be useful in monitoring airway inflammation resolution and improvement of health status during AECOPD treatment.

Longitudinal change in quality of life following hospitalisation for acute exacerbations of COPD

Background

Current guidelines for management of patients hospitalised with acute exacerbations of chronic obstructive pulmonary disease (COPD) recommend that clinical decisions, including escalation to assisted ventilation, be informed by an estimate of the patients’ likely postdischarge quality of life. There is little evidence to inform predictions of outcome in terms of quality of life, psychological well-being and functional status. Undue nihilism might lead to denial of potentially life-saving therapy, while undue optimism might prolong suffering when alternative palliation would be more appropriate. This study aimed to detail longitudinal changes in quality of life following hospitalisation for acute exacerbations of COPD.

Methods

We prospectively recruited two cohorts (exacerbations requiring assisted ventilation during admission and exacerbations not ventilated). Admission clinical data, and mortality and readmission details were collected. Quality of life, psychological well-being and functional status were formally assessed over the subsequent 12 months. Time-adjusted mean change in quality of life was examined.

Results

183 patients (82 ventilated; 101 not ventilated) were recruited. On average, overall quality of life improved by a clinically important amount in those not ventilated and did not decline in ventilated patients. Both groups showed clinically important improvements in respiratory symptoms and an individual's sense of control over their condition, despite the tendency for functional status to decline.

Conclusions

On average, postdischarge quality of life improved in non-ventilated and did not decline in ventilated patients. Certain quality of life domains (ie, symptoms and mastery) improved significantly. Better understanding of longitudinal change in postdischarge quality of life should help to inform decision-making.

Dynamics of inflammation resolution and symptom recovery during AECOPD treatment

The association between increases in both systemic and airway inflammation and acute exacerbation of COPD (AECOPD) has been reported by many studies. However, relatively little is known about the dynamics of inflammation resolution and their correlations with the improvement of clinical indices during treatment. In this study, a total of 93 consecutively hospitalized patients with AECOPD were recruited. Sputum and serum inflammatory markers were measured on the day of admission before treatment (day 0), day 4, 7 and 14 during treatment as well as 8 weeks after discharge. Clinical indices (lung function, dyspnea and COPD assessment test (CAT) scores) were also measured at those time points. By day 4, all airway inflammatory measures rapidly decreased and returned to baseline level. Notably, lung function and dyspnea improved to the baseline level by day 4 as well, consistent with the resolution of respiratory inflammation. However, despite the significant decrease by day 4, systemic inflammation did not reach baseline until day 14, concordant with the decrease in CAT score. In summary, we observed a time lag between the resolution of systemic and airway inflammation, which were correlated with the improvements of different clinical indices.

Changes of HMGB1 and sRAGE during the recovery of COPD exacerbation

BACKGROUND

Acute exacerbation of chronic obstructive pulmonary disease is associated with increased airway and systemic inflammation. However, the correlation between acute exacerbation/convalescence of chronic obstructive pulmonary disease (COPD) and simultaneous changes of high mobility group protein B1 (HMGB1) and soluble RAGE (sRAGE) levels has not been clearly clarified. The aim of this study was to assess these issues.

METHODS

A total of 44 COPD patients were recruited. Following a structured interview, plasma levels of HMGB1, sRAGE, fibrinogen and serum level of high-sensitivity C-reactive protein (hsCRP) were measured in patients with acute exacerbation of COPD (AECOPD) within 24 h of hospitalization and pre-discharge (convalescence). All patients were examined with spirometry in convalescence of COPD.

RESULTS

There was a significant decline in plasma HMGB1 (P<0.01), sRAGE (P<0.05), fibrinogen (P<0.01) and serum hsCRP (P<0.01) levels from acute exacerbation to convalescence phase of COPD. Changes of sRAGE was significantly correlated with changes of HMGB1 (r=0.4, P=0.007). COPD disease status correlated with the ratio of HMGB1/sRAGE, but not gender, age, course of disease, smoking history and FEV1% pred. Levels of HMGB1 and sRAGE were the highest in the current smoker group, and significantly decreased in ex-smoker group in both acute exacerbation and convalescence phase of COPD, however, their levels in never smoker group were higher than ex-smoker group in either phase of COPD.

CONCLUSIONS

HMGB1 and sRAGE levels were dynamically changed between exacerbation and convalescence phase of COPD, HMGB1 and sRAGE were likely not only a potential marker in COPD exacerbation but also a therapeutic target for COPD treatment.

The role of microparticles in chronic obstructive pulmonary disease

Accumulating evidence suggests that cell injury in lung tissues is closely connected to disease progression in chronic obstructive pulmonary disease (COPD). Microparticles (MPs) are shed membrane vesicles that are released from platelets, leukocytes, red blood cells, and endothelial cells when these cells are activated or undergo apoptosis under inflammatory conditions. Based on increasing evidence that endothelial injury in the pulmonary capillary vasculature leads to lung destruction, and because cardiovascular diseases are the main cause of death among individuals with COPD, endothelial MPs (EMPs) are now receiving attention as potential biomarkers for COPD. There are eight types of EMPs which are defined by the presence of different endothelial markers on the cell membrane: vascular endothelial-cadherin; platelet endothelial cell adhesion molecule; melanoma cell adhesion molecule; E-selectin; CD51; CD105; von Willebrand factor; and CD143 EMPs. Vascular endothelial-cadherin, platelet endothelial cell adhesion molecule, and E-selectin EMPs are increased in patients with stable COPD and are further increased in patients with exacerbated COPD compared to non-COPD patients. In addition, the levels of these three EMPs in patients with stable COPD are significantly correlated with lung destruction and airflow limitation. These results indicate that endothelial injury is closely connected to the pathophysiology of COPD. Interestingly, the variations in the levels of the eight EMP subtypes were not identical with changes in patient condition. Although the clinical significance of the differences in these eight EMP subtypes remains unclear, evaluating the expression pattern of endothelial antigens on circulating MPs might predict the presence and degree of endothelial injury in COPD patients. In addition, circulating MPs are proposed to have several physiological functions in vivo, such as intercellular crosstalk; the increase in EMPs in COPD seems to play a role in the pathophysiology of this disease.

Time course of inflammation resolution in patients with frequent exacerbations of chronic obstructive pulmonary disease

BACKGROUND

When exacerbation of chronic obstructive pulmonary disease (AECOPD) occurs frequently, patients have high levels of airway and systemic inflammation and a poor quality of life. This study compared the nature and course of systemic and airway inflammation during AECOPD between patients who experienced frequent exacerbations and those with non-frequent exacerbations.

MATERIAL AND METHODS

Consecutive hospitalized patients with AECOPD were recruited and divided into 2 groups according to the frequency of AECOPD they had experienced in the previous year. Frequent exacerbators (defined as 2 or more AECOPD in the previous year) and non-frequent exacerbators (defined as zero or 1 AECOPD in the previous year). Inflammatory (interleukin 6, interleukin 8, myeloperoxidase, and C-reactive protein) and clinical (dyspnea, COPD assessment test (CAT), and peak expiratory flow) indices were assessed on the day of admission before starting therapy, day 7 of treatment, the day of planned discharge (day 10-14), and 8 weeks after discharge.

RESULTS

We analyzed data from 135 patients; 78 (57.8%) were non-frequent exacerbators and 57 (42.2%) were frequent exacerbators. In both groups, the inflammatory and clinical indices at day 7, the day of planned discharge (day 10-14), and 8 weeks were significantly improved compared to those at admission. Frequent exacerbators had a smaller reduction in their inflammatory indices and CAT scores between exacerbation onset and all the other time points compared with infrequent exacerbators.

CONCLUSIONS

Frequent exacerbators have a reduced response to treatment of AECOPD in terms of inflammatory indices and quality of life.

Experimental rhinovirus infection in COPD: implications for antiviral therapies

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COPD exacerbations are a major cause of morbidity and mortality; new treatments are urgently needed.

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Respiratory viruses, particularly rhinoviruses, are a major cause of exacerbations.

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Experimental rhinovirus infection is a valid model of virus-induced COPD exacerbations.

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This model could be used to evaluate new antiviral treatments in COPD.

Chronic obstructive pulmonary disease (COPD) is a major public health problem and will be one of the leading global causes of mortality over the coming decades. Much of the morbidity, mortality and health care costs of COPD are attributable to acute exacerbations, the commonest causes of which are respiratory infections. Respiratory viruses are frequently detected in COPD exacerbations but direct proof of a causative relationship has been lacking. We have developed a model of COPD exacerbation using experimental rhinovirus infection in COPD patients and this has established a causative relationship between virus infection and exacerbations. In addition it has determined some of the molecular mechanisms linking virus infections to COPD exacerbations and identified potential new therapeutic targets. This new data should stimulate research into the role of antiviral agents as potential treatments for COPD exacerbations. Testing of antiviral agents has been hampered by the lack of a small animal model for rhinovirus infection and experimental rhinovirus infection in healthy volunteers has been used to test treatments for the common cold. Experimental rhinovirus infection in COPD subjects offers the prospect of a model that can be used to evaluate the effects of new treatments for virus-induced COPD exacerbations, and provide essential data that can be used in making decisions regarding large scale clinical trials.

Biomarkers in COPD

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease that cannot be described by the severity of airflow limitation (forced expiratory volume in the first second of expiration) only. Other measures are needed in clinical practice to assess patients, predict their risk, guide their treatment, and assess their response to it. Over the past few years, there has been a great deal of interest in the identification and validation of biomarkers of potential clinical use in COPD. Here, the authors review some general concepts in the field, discuss currently validated biomarkers in COPD, and speculate on potential future developments.

Pulmonary biomarkers in COPD exacerbations: a systematic review

Exacerbations of COPD (ECOPD) represent a major burden for patients and health care systems. Innovative sampling techniques have led to the identification of several pulmonary biomarkers. Although some molecules are promising, their usefulness in clinical practice is not yet established. Medline and Highwire databases were used to identify studies evaluating pulmonary sampled biomarkers in ECOPD. We combined 3 terms for ECOPD, 3 for biomarkers and 6 for the sampling method. Seventy-nine studies were considered eligible for inclusion in the review and were analyzed further. Pulmonary biomarkers sampled with non-invasive, semi-invasive and invasive methods were evaluated for their potential to illustrate the disease's clinical course, to correlate to clinical variables and to predict clinical outcomes, ECOPD etiology and response to treatment. According to published data several pulmonary biomarkers assessed in ECOPD have the potential to illustrate the natural history of disease through the modification of their levels. Among the clinically relevant molecules, those that have been studied the most and appear to be promising are spontaneous and induced sputum biomarkers for reflecting clinical severity and symptomatic recovery, as well as for directing towards an etiological diagnosis. Current evidence on the clinical usefulness of exhaled breath condensate and bronchoalveolar lavage biomarkers in ECOPD is limited. In conclusion, pulmonary biomarkers have the potential to provide information on the mechanisms underlying ECOPD, and several correlate with clinical variables and outcomes. However, on the basis of published evidence, no single molecule is adequately validated for wide clinical use. Clinical trials that incorporate biomarkers in decisional algorithms are required.

Course of COPD assessment test (CAT) and clinical COPD questionnaire (CCQ) scores during recovery from exacerbations of chronic obstructive pulmonary disease

Introduction

COPD exacerbations have a negative impact on lung function, decrease quality of life (QoL) and increase the risk of death. The objective of this study was to assess the course of health status after an outpatient or inpatient exacerbation in patients with COPD.

Methods

This is an epidemiological, prospective, multicentre study that was conducted in 79 hospitals and primary care centres in Spain. Four hundred seventy-six COPD patients completed COPD assessment test (CAT) and Clinical COPD Questionnaire (CCQ) questionnaires during the 24 hours after presenting at hospital or primary care centres with symptoms of an exacerbation, and also at weeks 4–6. The scores from the CAT and CCQ were evaluated and compared at baseline and after recovery from the exacerbation.

Results

A total of 164 outpatients (33.7%) and 322 inpatients (66.3%) were included in the study. The majority were men (88.2%), the mean age was 69.4 years (SD = 9.5) and the mean FEV1 (%) was 47.7% (17.4%). During the exacerbation, patients presented high scores in the CAT: [mean: 22.0 (SD = 7.0)] and the CCQ: [mean: 4.4 (SD = 1.2)]. After recovery there was a significant reduction in the scores of both questionnaires [CAT: mean: -9.9 (SD = 5.1) and CCQ: mean: -3.1 (SD = 1.1)]. Both questionnaires showed a strong correlation during and after the exacerbation and the best predictor of the magnitude of improvement in the scores was the severity of each score at onset.

Conclusions

Due to their good correlation, CAT and CCQ can be useful tools to measure health status during an exacerbation and to evaluate recovery. However, new studies are necessary in order to identify which factors are influencing the course of the recovery of health status after a COPD exacerbation.

Putting health status guided COPD management to the test: protocol of the MARCH study

BACKGROUND

Chronic Obstructive Pulmonary Disease (COPD) is a disease state characterized by airflow limitation that is not fully reversible and usually progressive. Current guidelines, among which the Dutch, have so far based their management strategy mainly on lung function impairment as measured by FEV1, while it is well known that FEV1 has a poor correlation with almost all features of COPD that matter to patients. Based on this discrepancy the GOLD 2011 update included symptoms and impact in their treatment algorithm proposal. Health status measures capture both symptoms and impact and could therefore be used as a standardized way to capture the information a doctor could otherwise only collect by careful history taking and recording. We hypothesize that a treatment algorithm that is based on a simple validated 10 item health status questionnaire, the Clinical COPD Questionnaire (CCQ), improves health status (as measured by SGRQ) and classical COPD outcomes like exacerbation frequency, patient satisfaction and health care utilization compared to usual care based on guidelines.

METHODS/DESIGN

This hypothesis will be tested in a randomized controlled trial (RCT) following 330 patients for two years. During this period general practitioners will receive treatment advices every four months that are based on the patient's health status (in half of the patients, intervention group) or on lung function (the remaining half of the patients, usual care group).

DISCUSSION

During the design process, the selection of outcomes and the development of the treatment algorithm were challenging. This is discussed in detail in the manuscript to facilitate researchers in designing future studies in this changing field of implementation research.

TRIAL REGISTRATION

Netherlands Trial Register, NTR2643.

Day-to-day measurement of patient-reported outcomes in exacerbations of chronic obstructive pulmonary disease

Background

Exacerbations of chronic obstructive pulmonary disease (COPD) are a major burden to patients and to society. Little is known about the possible role of day-to-day patient-reported outcomes during an exacerbation. This study aims to describe the day-to-day course of patient-reported health status during exacerbations of COPD and to assess its value in predicting clinical outcomes.

Methods

Data from two randomized controlled COPD exacerbation trials (n = 210 and n = 45 patients) were used to describe both the feasibility of daily collection of and the day-to-day course of patient-reported outcomes during outpatient treatment or admission to hospital. In addition to clinical parameters, the BORG dyspnea score, the Clinical COPD Questionnaire (CCQ), and the St George’s Respiratory Questionnaire were used in Cox regression models to predict treatment failure, time to next exacerbation, and mortality in the hospital study.

Results

All patient-reported outcomes showed a distinct pattern of improvement. In the multivariate models, absence of improvement in CCQ symptom score and impaired lung function were independent predictors of treatment failure. Health status and gender predicted time to next exacerbation. Five-year mortality was predicted by age, forced expiratory flow in one second % predicted, smoking status, and CCQ score. In outpatient management of exacerbations, health status was found to be less impaired than in hospitalized patients, while the rate and pattern of recovery was remarkably similar.

Conclusion

Daily health status measurements were found to predict treatment failure, which could help decision-making for patients hospitalized due to an exacerbation of COPD.

Delayed resolution of inflammatory response compared with clinical recovery in patients with acute exacerbations of chronic obstructive pulmonary disease

BACKGROUND AND OBJECTIVE

The temporal profile of inflammatory markers during acute exacerbations of chronic obstructive pulmonary disease (AECOPD) and their relationship to clinical response are not well characterized. The aim was to assess the changes in levels of inflammatory markers in AECOPD and correlate these with clinical and laboratory indices of recovery.

METHODS

Serum levels of C-reactive protein (CRP), interleukin (IL)-6 and fibrinogen were measured in patients with AECOPD within 24 h of hospitalization and pre-discharge (stable state).

RESULTS

Ninety-seven patients were evaluated (79 males; mean (SD) age, 61.4 (10.3) years). Eighty eight (90.7%) were current or former smokers, with a median consumption of 15 (0-75) packs/year. The median duration of COPD was 8 (2-25) years. Forty-six patients (56.9%) required mechanical ventilation for a median of 5 days (1-34) while in hospital. The median duration of hospital stay was 13 days (1-77). At reassessment before planned discharge, the levels of dyspnoea, leucocyte counts, erythrocyte sedimentation rate, creatinine, partial pressure of oxygen, and albumin normalized. The levels of CRP, IL-6 and fibrinogen reduced significantly but did not reach the normal range. Changes in IL-6 and fibrinogen levels correlated significantly with the acute physiologic assessment and chronic health evaluation II score, smoking history, blood pressure and leucocyte counts. Baseline IL-6 and fibrinogen levels significantly predicted a prolonged duration of mechanical ventilation.

CONCLUSIONS

During AECOPD, the inflammatory response lags behind clinical and biochemical improvement. Fibrinogen and IL-6 are potentially useful markers for monitoring clinical response following an acute episode.

Fetuin-A is associated with disease severity and exacerbation frequency in patients with COPD

Fetuin-A is a liver protein that may serve as an inhibitor of systemic inflammation in humans. In the present study we assessed the levels of fetuin-A in COPD patients in stable condition and on exacerbation in an attempt to evaluate it as a clinically relevant biomarker that may serve as predictor of exacerbations of COPD (ECOPD). One hundred COPD outpatients (GOLD stage I to IV) were enrolled in a tertiary University hospital and were submitted to a detailed evaluation, including pulmonary function testing, exercise capacity, quality of life and evaluation of the presence of metabolic syndrome and serum CRP. All patients were followed-up for 1 year, and 36 were re-evaluated at the onset of an ECOPD. Forty otherwise healthy smokers served as controls. Serum fetuin-A levels were reproducible at baseline, 6 and 12 months. COPD patients presented lower levels of fetuin compared to controls [394.5 (321.8-419.6) vs. 487.3 (441.0-548.0) mg/L, p < 0.001]. COPD patients with GOLD stage IV had lower fetuin-A levels compared to stages I-II and III (p < 0.05). Fetuin-A was significantly reduced at the onset of an ECOPD compared to baseline (p < 0.001) and the time to the first ECOPD significantly different between patients with high and low levels of fetuin-A [HR 2.163 (95%CI 1.104-4.238), p = 0.024). The results of the present study suggest that fetuin-A is a reproducible and clinically relevant biomarker in patients with COPD that may be useful in the identification of exacerbation-prone patients.

Blood fibrinogen as a biomarker of chronic obstructive pulmonary disease

Background

Chronic obstructive pulmonary disease (COPD) is a multicomponent condition that is characterised by airflow obstruction that is not fully reversible and is a major global cause of morbidity and mortality. The most widely used marker of disease severity and progression is FEV₁. However, FEV₁ correlates poorly with both symptoms and other measures of disease progression and thus there is an urgent need for other biological markers to better characterise individuals with COPD. Fibrinogen is an acute phase plasma protein that has emerged as a promising biomarker in COPD. Here we review the current clinical evidence linking fibrinogen with COPD and its associated co-morbidities and discuss its potential utility as a biomarker.

Methods

Searches for appropriate studies were undertaken on PubMed using search terms fibrinogen, COPD, emphysema, chronic bronchitis, FEV₁, cardiovascular disease, exacerbation and mortality.

Results

There is strong evidence of an association between fibrinogen and the presence of COPD, the presence and frequency of exacerbations and with mortality. Fibrinogen is associated with disease severity but does not predict lung function decline, a measure used as a surrogate for disease activity. The role of fibrinogen in identifying inflammatory co morbidities, particularly cardiovascular disease, remains unclear. Fibrinogen is reduced by p38 mitogen-activated protein kinase inhibitors in individuals with stable disease and by oral corticosteroids during exacerbations.

Conclusions

Fibrinogen is likely to be a useful biomarker to stratify individuals with COPD into those with a high or low risk of future exacerbations and may identify those with a higher risk of mortality.

Determination of inflammatory biomarkers in patients with COPD: a comparison of different assays

Background

Chronic obstructive pulmonary disease (COPD) is an inflammatory pulmonary disorder with systemic inflammatory manifestations that are mediated by circulating acute-phase reactants. This study compared an enzyme-linked immunosorbent assay (ELISA) to a nephelometric technique for the measurement of serum C-reactive protein (CRP) and serum amyloid A (SAA) and investigated how the choice of assay influenced the estimation of inflammation in patients with stable COPD.

Methods

CRP and SAA concentrations measured by ELISA and nephelometry in 88 patients with COPD and 45 control subjects were used to evaluate the performance of these methods in a clinical setting.

Results

With both assays, the concentrations of CRP and SAA were higher in COPD patients than in controls after adjustment for age and sex. There was a moderate correlation between the values measured by ELISA and those measured by nephelometry (logCRP: r = 0.55, p < 0.001; logSAA: r = 0.40, p < 0.001). However, the concentrations of biomarkers determined by nephelometry were significantly higher than those obtained with ELISA for CRP (mean difference = 2.7 (9.4) mg/L) and SAA (mean difference = 0.31 (14.3) mg/L).

Conclusion

Although the serum CRP and SAA concentrations measured by ELISA and nephelometry correlated well in COPD patients, the ELISA values tended to be lower for CRP and SAA when compared with nephelometric measurements. International standardization of commercial kits is required before the predictive validity of inflammatory markers for patients with COPD can be effectively assessed in clinical practice.

Cyclooxygenase-2 -765G>C polymorphism is associated with C-reactive protein levels in resistant smokers but not in chronic obstructive pulmonary disease patients

We sought to investigate whether the serum concentrations of several inflammatory biomarkers are related to the cyclooxygenase-2 (COX2) -765G>C polymorphism in chronic obstructive pulmonary disease (COPD) and a control group of non-COPD smokers. Serum inflammatory markers (CRP, SAA, CXCL8, and sICAM-1) were measured by ELISA in 144 patients with COPD and in 55 control subjects. Genomic DNA was extracted from peripheral blood leukocytes, and the COX2 -765G>C (rs20417) polymorphism was genotyped. After adjustment for age and active smoking, CRP and SAA concentrations were associated with the COX2 polymorphism in controls (p=0.041 and 0.014, respectively) but not in COPD patients. The CXCL8 and sICAM-1 concentrations were not associated with the COX2 polymorphism for either cases or controls. The results of the present study indicate that there is a relationship between the COX2 -765G>C polymorphism and the concentrations of CRP and SAA in non-COPD smokers and that this relationship does not exist in COPD patients.

Systemic biomarkers in exacerbations of COPD: the evolving clinical challenge

BACKGROUND

Exacerbations of COPD (ECOPD) remain a major cause of mortality and morbidity. Despite advances in the understanding of their pathophysiology, their assessment relies primarily on clinical presentation, which can be variable and difficult to predict. A large number of biomarkers already have been assessed in this context, and some appear to be promising.

METHODS

An online search for articles published until December 2010 was conducted using three terms for ECOPD, five terms for biomarkers, and five terms for the sampling method. Biomarkers were evaluated for their potential role in the establishment and confirmation of the diagnosis of ECOPD, the evaluation of etiology and severity, the prediction of prognosis, and the guidance of treatment decisions.

RESULTS

Several systemic biomarkers have been measured in the context of ECOPD, and most have been found to increase at ECOPD onset and to subside during the course of exacerbations. Correlations have been reported among these biomarkers, but direct associations with clinical variables have been more difficult to establish. Although there are several limitations yet to be addressed, some of the biomarkers, most notably C-reactive protein for the identification of an ECOPD and procalcitonin for antibiotic guidance, may provide clinically relevant information.

CONCLUSIONS

So far, no single biomarker has been able to gain wide acceptance, but some provide clinically useful information. The evaluation of such biomarkers in large decision-making studies is expected to become an area of intense investigation in the near future.