Value of C-reactive protein measurements in exacerbations of chronic obstructive pulmonary disease

Parallel detection of multiple biomarkers in a point-of-care-competent device for the prediction of exacerbations in chronic inflammatory lung disease

Sudden aggravations of chronic inflammatory airway diseases are difficult-to-foresee life-threatening episodes for which advanced prognosis-systems are highly desirable. Here we present an experimental chip-based fluidic system designed for the rapid and sensitive measurement of biomarkers prognostic for potentially imminent asthma or COPD exacerbations. As model biomarkers we chose three cytokines (interleukin-6, interleukin-8, tumor necrosis factor alpha), the bacterial infection marker C-reactive protein and the bacterial pathogen Streptococcus pneumoniae-all relevant factors in exacerbation episodes. Assay protocols established in laboratory environments were adapted to 3D-printed fluidic devices with emphasis on short processing times, low reagent consumption and a low limit of detection in order to enable the fluidic system to be used in point-of-care settings. The final device demonstrator was validated with patient sample material for its capability to detect endogenous as well as exogenous biomarkers in parallel.

Indoor and ambient black carbon and fine particulate matter associations with blood biomarkers in COPD patients

BACKGROUND

Systemic inflammation contributes to cardiovascular risk and chronic obstructive pulmonary disease (COPD) pathophysiology. Associations between systemic inflammation and exposure to ambient fine particulate matter (PM ≤ 2.5 μm diameter; PM2.5), and black carbon (BC), a PM2.5 component attributable to traffic and other sources of combustion, infiltrating indoors are not well described.

METHODS

Between 2012 and 2017, COPD patients completed in-home air sampling over one-week intervals, up to four times (seasonally), followed by measurement of plasma biomarkers of systemic inflammation, C-reactive protein (CRP) and interleukin-6 (IL-6), and endothelial activation, soluble vascular adhesion molecule-1 (sVCAM-1). Ambient PM2.5, BC and sulfur were measured at a central site. The ratio of indoor/ambient sulfur in PM2.5, a surrogate for fine particle infiltration, was used to estimate indoor BC and PM2.5 of ambient origin. Linear mixed effects regression with a random intercept for each participant was used to assess associations between indoor and indoor of ambient origin PM2.5 and BC with each biomarker.

RESULTS

144 participants resulting in 482 observations were included in the analysis. There were significant positive associations between indoor BC and indoor BC of ambient origin with CRP [%-increase per interquartile range (IQR);95 % CI (13.2 %;5.2-21.8 and 11.4 %;1.7-22.1, respectively)]. Associations with indoor PM2.5 and indoor PM2.5 of ambient origin were weaker. There were no associations with IL-6 or sVCAM-1.

CONCLUSIONS

In homes of patients with COPD without major sources of combustion, indoor BC is mainly attributable to the infiltration of ambient sources of combustion indoors. Indoor BC of ambient origin is associated with increases in systemic inflammation in patients with COPD, even when staying indoors.

Validation of the Rome Severity Classification of Chronic Obstructive Pulmonary Disease Exacerbation: A Multicenter Cohort Study

Background

The Rome severity classification is an objective assessment tool for the severity of acute exacerbations of chronic obstructive pulmonary disease (AECOPD) based on readily measurable variables but has not been widely validated. The aim of this study is to evaluate the validity of the Rome classification in distinguishing the severity of AECOPD based on short-term mortality and other adverse outcomes.

Methods

The Rome severity classification was applied to a large multicenter cohort of inpatients with AECOPD. Differences in clinical features, in-hospital and 60-day mortality, intensive care unit (ICU) admission, mechanical ventilation (MV) and invasive mechanical ventilation (IMV) usage were compared among the mild, moderate and severe AECOPD according to the Rome proposal. Moreover, univariate logistic analysis and Kaplan Meier survival analysis were also performed to find the association between the Rome severity classification and those adverse outcomes.

Results

A total of 7712 patients hospitalized for AECOPD were included and classified into mild (41.88%), moderate (40.33%), or severe (17.79%) group according to the Rome proposal. The rate of ICU admission (6.4% vs 12.0% vs 14.9%, P <0.001), MV (11.7% vs 33.7% vs 45.3%, P <0.001) and IMV (1.4% vs 6.8% vs 8.9%, P <0.001) increased significantly with the increase of severity classification from mild to moderate to severe AECOPD. The 60-day mortality was higher in the moderate or severe group than in the mild group (3.5% vs 1.9%, 4.3% vs 1.9%, respectively, P <0.05) but showed no difference between the moderate and severe groups (2.6% vs 2.5%, P >0.05), results for in-hospital mortality showed the same trends. Similar findings were observed by univariate logistic analysis and survival analysis.

Conclusion

Rome severity classification demonstrated excellent performance in predicting ICU admission and the need for MV or IMV, but how it performs in differentiating short-term mortality still needs to be confirmed.

Application of the Rome severity classification of COPD exacerbations in a real-world cohort of hospitalised patients

Background

Recently, the Rome classification was proposed in which objective and readily measurable variables were integrated to mark exacerbations of COPD (ECOPD) severity. The aim of this study is to investigate the distribution of a real-world patient population with hospitalised ECOPD according to the current classification across the newly proposed severity classification. We assume that a significant proportion of hospitalised patients will have a mild or moderate event.

Methods

The Rome classification was applied to a cohort of 364 COPD patients hospitalised at the Department of Respiratory Medicine of Maastricht University Medical Center (MUMC) with a severe ECOPD. Differences in in-hospital, 30- and 90-day mortality were compared between mild, moderate and severe ECOPD according to the new classification. Moreover, data were stratified by the different severity classes and compared regarding general disease characteristics and clinical parameters.

Results

According to the Rome proposal, 52 (14.3%) patients had a mild ECOPD, 204 (56.0%) a moderate and 108 (29.7%) a severe ECOPD. In-hospital mortality in mild, moderate and severe events was 3.8%, 6.9% and 13.9%, respectively. Most clinical parameters indicated a significantly worse condition in patients classified in the severe group, compared to those in mild or moderate groups.

Conclusion

Most of the events, traditionally all classified as severe because of the hospitalisation, were classified as moderate, while almost 15% were mild. The results of this study provide insight into the heterogeneity of hospitalised ECOPD and show that the newly proposed Rome criteria can differentiate between events with different short-term mortality rates.

11β-HSD1 determines the extent of muscle atrophy in a model of acute exacerbation of COPD

Muscle atrophy is an extrapulmonary complication of acute exacerbations (AE) in chronic obstructive pulmonary disease (COPD). The endogenous production and therapeutic application of glucocorticoids (GCs) have been implicated as drivers of muscle loss in AE-COPD. The enzyme 11 β-hydroxysteroid dehydrogenase 1 (11β-HSD1) activates GCs and contributes toward GC-induced muscle wasting. To explore the potential of 11βHSD1 inhibition to prevent muscle wasting here, the objective of this study was to ascertain the contribution of endogenous GC activation and amplification by 11βHSD1 in skeletal muscle wasting during AE-COPD. Emphysema was induced by intratracheal (IT) instillation of elastase to model COPD in WT and 11βHSD1/KO mice, followed by vehicle or IT-LPS administration to mimic AE. µCT scans were obtained prior and at study endpoint 48 h following IT-LPS, to assess emphysema development and muscle mass changes, respectively. Plasma cytokine and GC profiles were determined by ELISA. In vitro, myonuclear accretion and cellular response to plasma and GCs were determined in C2C12 and human primary myotubes. Muscle wasting was exacerbated in LPS-11βHSD1/KO animals compared with WT controls. RT-qPCR and western blot analysis showed elevated catabolic and suppressed anabolic pathways in muscle of LPS-11βHSD1/KO animals relative to WTs. Plasma corticosterone levels were higher in LPS-11βHSD1/KO animals, whereas C2C12 myotubes treated with LPS-11βHSD1/KO plasma or exogenous GCs displayed reduced myonuclear accretion relative to WT counterparts. This study reveals that 11β-HSD1 inhibition aggravates muscle wasting in a model of AE-COPD, suggesting that therapeutic inhibition of 11β-HSD1 may not be appropriate to prevent muscle wasting in this setting.

Biomarkers to guide the use of antibiotics for acute exacerbations of COPD (AECOPD): a systematic review and meta-analysis

Background

Antibiotics are frequently prescribed for acute exacerbations of COPD (AECOPD) even though most do not have a bacterial aetiology. Biomarkers may help clinicians target antibiotic use by identifying AECOPD caused by bacterial pathogens. We aimed to summarise current evidence on the diagnostic accuracy of biomarkers for detecting bacterial versus non-bacterial AECOPD.

Methods

We searched Embase and Medline using a search strategy including terms for COPD, biomarkers and bacterial infection. Data regarding diagnostic accuracy for each biomarker in predicting bacterial cause of exacerbation were extracted and summarised. We used to QUADAS-2 tool to assess risk of bias.

Results

Of 509 papers identified, 39 papers evaluating 61 biomarkers were eligible for inclusion. Moderate quality evidence was found for associations between serum C-reactive protein (CRP), serum procalcitonin (PCT), sputum interleukin (IL)-8 and sputum tumour necrosis factor alpha (TNF-α), and the presence of bacterial pathogens in the sputum of patients with AECOPD. Having bacterial pathogens was associated with a mean difference (higher) CRP and PCT of 29.44 mg/L and 0.76 ng/mL respectively. There was inconsistent or weak evidence for associations between bacterial AECOPD and higher levels of sputum IL-1β, IL-6, myeloperoxidase (MPO) and neutrophil elastase (NE). We did not find any consistent evidence of diagnostic value for other biomarkers.

Conclusions

There is moderate evidence from heterogeneous studies that serum CRP and PCT are of value in differentiating bacterial from non-bacterial AECOPD, and little evidence for other biomarkers. Further high-quality research on the role of biomarkers in identifying bacterial exacerbations is needed.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-01958-4.

Point-of-care COPD diagnostics: biomarkers, sampling, paper-based analytical devices, and perspectives

Chronic obstructive pulmonary disease (COPD) has become the third leading cause of global death. Insufficiency in early diagnosis and treatment of COPD, especially COPD exacerbations, leads to a tremendous economic burden and medical costs. A cost-effective and timely prevention requires decentralized point-of-care diagnostics at patients' residences at affordable prices. Advances in point-of-care (POC) diagnostics may offer new solutions to reduce medical expenditures by measuring salivary and blood biomarkers. Among them, paper-based analytical devices have been the most promising candidates due to their advantages of being affordable, biocompatible, disposable, scalable, and easy to modify. In this review, we present salivary and blood biomarkers related to COPD endotypes and exacerbations, summarize current technologies to collect human whole saliva and whole blood samples, evaluate state-of-the-art paper-based analytical devices that detect COPD biomarkers in saliva and blood, and discuss existing challenges with outlooks on future paper-based POC systems for COPD diagnosis and management.

Inflammatory Biomarkers Are Inaccurate Indicators of Bacterial Infection on Admission in Patients With Acute Exacerbation of Chronic Obstructive Pulmonary Disease-A Systematic Review and Diagnostic Accuracy Network Meta-Analysis

Introduction: The value of inflammatory biomarkers in the diagnosis of bacterial infection induced acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is currently unclear. Our objective was to investigate the diagnostic accuracy of on-admission inflammatory biomarkers in differentiating bacterial origin in AECOPD.

Methods: Systematic literature search was performed to include cross-sectional studies on AECOPD patients with microbiological culture results as gold standard, and at least one on-admission inflammatory biomarker determined from serum: C-reactive protein (CRP), procalcitonin (PCT), neutrophil/lymphocyte ratio, eosinophil percentage, CD64index; or sputum: neutrophil elastase, tumor necrosis factor alfa, interleukin-1-beta (IL-1b), interleukin-8, sputum color, as index tests. We ranked index tests by superiority indices in a network meta-analysis and also calculated pooled sensitivity and specificity.

Results: Altogether, 21 eligible articles reported data on 2,608 AECOPD patients (44% bacterial). Out of the 14 index tests, sputum IL-1b showed the highest diagnostic performance with a pooled sensitivity of 74% (CI: 26–97%) and specificity of 65% (CI: 19–93%). Pooled sensitivity for CRP and PCT were: 67% (CI: 54–77%) and 54% (CI: 39–69%); specificity 62% (CI: 52–71%) and 71% (CI: 59–79%), respectively.

Conclusion: Admission inflammatory biomarkers are inaccurate indicators of bacterial infection in AECOPD.

Systematic Review Registration:https://www.crd.york.ac.uk/prospero/#myprospero, identifier: 42020161301.

Combination antibiotic therapy versus monotherapy in the treatment of acute exacerbations of chronic obstructive pulmonary disease: an open-label randomized trial

Background

The role of antibiotics in the treatment of chronic obstructive pulmonary disease (COPD) exacerbations and their effectiveness in combination have not been clearly established. To determine whether using a combination of fluoroquinolones and beta-lactams improves the clinical and microbiological efficacy of antibiotics on day 20 of treatment, we conducted an open-label randomized trial based on clinical outcomes, microbiological clearance, spirometry tests, and signs of systemic inflammation in patients hospitalized with acute exacerbations of COPD.

Methods

We enrolled 139 subjects with COPD exacerbations, defined as acute worsening of respiratory symptoms leading to additional treatment. Patients were divided randomly into two groups: 79 patients using beta-lactam antibiotics alone and 60 using beta-lactam antibiotics plus fluoroquinolones. Clinical and microbiological responses, spirometry tests, symptom scores, and serum C-reactive protein (CRP) levels were evaluated.

Results

Clinical success, lung function, and symptoms were similar in patients with or without fluoroquinolone administration on days 10 and 20. Combination therapy was superior in terms of microbiological outcomes and reduction in serum CRP value. Although equivalent to monotherapy in terms of clinical success, the combination showed superiority in terms of microbiological success and a decrease in CRP. The combination therapy group had a higher microbiological success rate with gram-negative bacteria than the monotherapy group with Pseudomonas aeruginosa (100% vs. 33.3%, respectively) and Acinetobacter baumanii (100% vs. 20%, respectively) (P < 0.05).

Conclusions

Concomitant use of fluoroquinolone and beta-lactam antibiotics for bacterial infections during COPD exacerbations caused by gram-negative bacteria appear to be effective and should be applied in clinical practice.

PARC/CCL18 is Associated with Inflammation, Emphysema Severity and Application of Inhaled Corticosteroids in Hospitalized COPD Patients

Background

Pulmonary and activation-regulated chemokine (PARC) also named CC-chemokine ligand 18 (CCL18) is a lung-predominant inflammatory protein that is found in serum. The relationship of PARC/CCL18 with the chronic obstructive pulmonary disease (COPD) is not fully understood. The aim of the present study is to analyze the expression of PARC/CCL18 in COPD.

Methods

Ninety-eight hospitalized COPD patients and 60 healthy volunteers from January 2019 to December 2019 were recruited in this retrospective study. Gender, age, height, weight, disease duration, smoking status, blood cell classification and count, length of hospital stay (LOS), symptom score, including COPD Assessment Test (CAT) score, modified British Medical Research Council (mMRC) score, lung function and therapy were recorded and serum PARC/CCL18 was analyzed by ELISA. The correlation between symptom score, blood cell classification and count, CRP, lung function parameters and serum levels of PARC/CCL18 and ROC curves of PARC/CCL18 levels and inhaled corticosteroids (ICS) were accessed.

Results

It was found that serum PARC/CCL18 level in hospitalized COPD population was significantly higher than that in healthy people (p=0.003). COPD patients with emphysema had significantly higher serum level of PARC/CCL18 than those without emphysema (p=0.049). Total lung capacity (TLC) and residual volume (RV)/TLC had positive correlation with serum level of PARC/CCL18 (p=0.001, 0.020, respectively). Furthermore, serum PARC/CCL18 level was predictive for the application ICS (p=0.003) and related to C-reactive protein (p <0.0001) in hospitalized COPD patients.

Conclusion

PARC/CCL18 is associated with the severity of inflammation and emphysema in COPD. Furthermore, PARC/CCL18 is a predictor of ICS application in the treatment of hospitalized COPD patients.

Sputum and salivary protein biomarkers and point-of-care biosensors for the management of COPD

Chronic obstructive pulmonary disease (COPD) has become one of the most fatal diseases of the century considering mortality and morbidity levels worldwide. This disease is an inflammatory response to environmental stress and tobacco smoking. Although spirometry is the gold-standard diagnostic test administrated in primary and secondary care, it often exhibits low accuracy in cases of predicting disease worsening and possible bias due to the operator, patient, and conditions. Recent developments in proteomics research suggest that the presence of protein biomarkers can aid in the accurate diagnosis and prediction of disease outcomes. This review presents the cutting-edge research progress in the area of protein biomarkers towards the management of COPD. The literature review was confined to protein biomarkers in saliva and sputum because testing these bodily fluids shows great promise for point-of-care (POC) testing due to its practicality, non-invasiveness and inexpensive handling and sampling. Although it is conclusive that more studies on sputum and saliva are needed, this review studies the promising clinical value of interleukin (IL)-6 and IL-8, matrix metalloproteinase (MMP)-8 and MMP-9, C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), and neutrophil elastase (NE). Following the critical analysis of salivary and sputum biomarkers, the recent development of POC biosensors for the multiplexed detection of biomarkers is also reported. Overall, the review aims to explore the possibility for the future development of POC sensors for chronic lung disease management utilizing clinically relevant biomarkers in saliva and sputum.

Serum Amyloid A in Stable COPD Patients is Associated with the Frequent Exacerbator Phenotype

Background

We sought to determine whether circulating inflammatory biomarkers were associated with the frequent exacerbator phenotype in stable COPD patients ie, those with two or more exacerbations in the previous year.

Methods

Eighty-eight stable, severe, COPD patients (4 females) were assessed for exacerbation frequency, pulmonary function, fraction of expired nitric oxide (F_ENO); inflammatory variables were measured in venous blood. Logistic regression assessed associations between the frequent exacerbator phenotype and systemic inflammation.

Results

Compared with infrequent exacerbators, frequent exacerbators (n=10; 11.4%) had greater serum concentration (median (25th-75th quartile)) of serum amyloid A (SAA; 134 (84–178) vs 71 (38–116) ng/mL; P=0.024), surfactant protein D (SP-D; 15.6 (9.0–19.3) vs 8.5 (3.6–14.9) ng/mL; P=0.049) and interleukin-4 (IL-4; 0.12 (0.08–1.44) vs 0.03 (0.01–0.10) pg/mL; P=0.001). SAA, SP-D and IL-4 were not significantly correlated with FEV₁%predicted or FVC %predicted. After adjusting for sex, age, BMI, FEV₁/FVC and smoking pack-years, only SAA remained independently associated with the frequent exacerbator phenotype (OR 1.49[1.09–2.04]; P=0.012). The odds of being a frequent exacerbator was 18-times greater in the highest SAA quartile (≥124.1 ng/mL) than the lowest SAA quartile (≤44.1 ng/mL) (OR 18.34[1.30–258.81]; P=0.031), and there was a significant positive trend of increasing OR with increasing SAA quartile (P=0.008). For SAA, the area under the receiver operating characteristic curve was 0.721 for identification of frequent exacerbators; an SAA cut-off of 87.0 ng/mL yielded an 80% sensitivity and 61.5% specificity.

Conclusion

In stable COPD patients, SAA was independently associated with the frequent exacerbator phenotype, suggesting that SAA may be a useful serum biomarker to inform progression or management in COPD.

Acute Phase Proteins as Predictors of Survival in Patients With Acute Exacerbation of Chronic Obstructive Pulmonary Disease Requiring Mechanical Ventilation

Few studies have tried to assess prognostic variables in chronic obstructive pulmonary disease (COPD) patients requiring mechanical ventilation (MV). We evaluated serum C reactive protein, (CRP) pre-albumin (PA) and transferrin (TR) levels in AE-COPD patients requiring MV as prognostic markers of in hospital mortality. 93 AE-COPD patients on MV were evaluated. Detailed clinical evaluation was done daily. Serum CRP & PA were measured on admission, 3rd, 8th and 16th day; TR was measured on admission, 8th and 16th day. Demographics, baseline parameters, CRP, PA and TR were correlated with mortality. Of 93 patients, 49 (52.69%) survived whereas 44 patients (47.31%) died. APACHE II, serum urea & albumin were similar in survivors & non-survivors. Baseline CRP (≥10.5 mg/dl) had sensitivity of 60.5%, specificity of 60.2%, with area under curve (AUC) of 0.62 as predictor of mortality. CRP (≥7 mg/dl) on day 3 had sensitivity (65.5%) and specificity (63.3%) with AUC 0.70 as predictor of mortality. Baseline serum prealbumin was 11.00 (0.09-29.26) mg/dl, and similar in survivors & non-survivors (p = 0.7). Prealbumin at day 8 (n = 50) < 13.5 mg/dl had sensitivity 54.6%, and specificity 51.4% with AUC 0.54 (95% CI 0.34-0.75) as predictor of mortality. Transferrin at day 8 (n = 50) of <148.9 had sensitivity 63.4% and specificity 61.4% with AUC 0.61 with respect to mortality. High CRP levels at baseline, persistently elevated CRP (on day 3) may predict mortality in AE-COPD patients requiring MV. Further studies are required to establish prognostic variables in this patient population.

Myocardial Infarction and Ischemic Stroke after Exacerbations of Chronic Obstructive Pulmonary Disease

RATIONALE

Previous studies have suggested that acute exacerbations of chronic obstructive pulmonary disease (COPD) may be associated with increased risk of myocardial infarction and ischemic stroke.

OBJECTIVES

We aimed to quantify the increased risks of myocardial infarction and ischemic stroke risk associated with both moderate and severe acute exacerbation, and to investigate factors that may modify these risks.

METHODS

We performed a self-controlled case series to investigate the rates of myocardial infarction and ischemic stroke after acute exacerbation compared with stable time, within individuals. The participants were 5,696 adults with COPD with a first myocardial infarction (n = 2,850) or ischemic stroke (n = 3,010) and at least one acute exacerbation from the UK Clinical Practice Research Datalink with linked Hospital Episodes Statistics data.

RESULTS

The risks of both myocardial infarction and ischemic stroke were increased in the 91 days after an acute exacerbation. The risks were greater after a severe exacerbation (incidence rate ratio [IRR], 2.58; 95% confidence interval [CI], 2.26-2.95 for myocardial infarction; and IRR, 1.97; 95% CI, 1.66-2.33 for ischemic stroke) than after a moderate exacerbation (IRR, 1.58; 95% CI, 1.46-1.71 for myocardial infarction; and IRR, 1.45; 95% CI, 1.33-1.57 for ischemic stroke). The relative risks of myocardial infarction and ischemic stroke associated with acute exacerbation were lower among those with more frequent exacerbations (IRR, 1.42; 95% CI, 1.24-1.62 vs. IRR, 1.69; 95% CI, 1.50-1.91 for myocardial infarction; and IRR, 1.30; 95% CI, 1.15-1.48 vs. IRR, 1.68; 95% CI, 1.50-1.89 for ischemic stroke). Higher GOLD stage was associated with a lower rate of myocardial infarction (IRR, 1.98; 95% CI, 1.61-2.05 vs. IRR, 1.69; 95% CI, 1.45-1.98) but not for ischemic stroke. Aspirin use at baseline was associated with a lower risk of ischemic stroke (IRR, 1.28; 95% CI, 1.10-1.50 vs. IRR, 1.63; 95% CI, 1.47-1.80) but not with myocardial infarction.

CONCLUSIONS

Acute exacerbations of COPD are associated with an increased risk of myocardial infarction and ischemic stroke within 28 days of their onset. Several patient characteristics were identified that are associated with these events.

Electrochemical methods for detection of biomarkers of Chronic Obstructive Pulmonary Disease in serum and saliva

Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death nowadays, and its underdiagnosis is still a great challenge. More effective diagnosis method is in urgent need since the traditional spirometry has many limitations in the practical application. The electrochemical (EC) detection methods have their unique advantages of high accuracy, short response time and easy integration of the system. In this review, recent works on the EC methods for COPD biomarkers including interleukin 6 (IL-6), interleukin 8 (IL-8) and C-reactive protein (CRP) are summarized. Five types of EC methods are highlighted in this study, as enzyme-labelled immunosensors, nanoparticle-labelled immunosensors, capacitive or impedimetric immunosensors, magnetoimmunosensors, and field effect transistor (FET) immunosensors. To date, EC immunosensors have been exhibiting high analytical performance with a detection limit that can achieve several pg/mL or even lower. The simplicity of EC immunosensors makes them a perfect solution for a future point-of-care device to use in settings for COPD diagnosis and follow-up. Nevertheless, more efforts need to be paid on the simultaneous detection of multiple biomarkers, a demand for the clinical diagnosis, and processes of assay simplification towards achieving one-step detection.

Is It Time to Change the Definition of Acute Exacerbation of Chronic Obstructive Pulmornary Disease? What Do We Need to Add?

Acute exacerbations in chronic obstructive pulmonary disease (AECOPD) are associated with increased mortality, rate of hospitalization, use of healthcare resources, and have a negative impact on disease progression, quality of life and lung function of patients with chronic obstructive pulmonary disease (COPD). There is an imperative need to homogenize the definition of AECOPD because the incidence of exacerbations has a significant influence or implication on treatment decision making, particularly in pharmacotherapy and could impact the outcome or change the statistical significance of a therapeutic intervention in clinical trials. In this review, using PubMed searches, we have analyzed the weaknesses and strengths of the different used AECOPD definitions (symptom-based, healthcare-based definition or the combinations of both), as well as the findings of the studies that have assessed the relationship of different biomarkers with the diagnosis, etiology and differential diagnosis of AECOPD and the progress towards the development of a more precise definition of COPD exacerbation. Finally, we have proposed a simple definition of AECOPD, which must be validated in future clinical trials to define its accuracy and usefulness in daily practice.

Blood biomarkers as predictors of long-term mortality in COPD

BACKGROUND

Blood biomarkers are easily accessible and might reflect chronic obstructive pulmonary disease (COPD) activity.

AIM

The aim of this study was to determine whether a panel of blood biomarkers [C-reactive protein (CRP), neutrophils, eosinophils, albumin and vitamin D] could predict mortality in COPD.

METHODS

We analyzed data from 431 COPD participants to the 2007-2010 National Health and Nutrition Examination Surveys who were followed for a median time of 36 months. COPD was defined as post-bronchodilator forced expiratory volume in 1 second (FEV1) and forced vital capacity ratio <0.70. Weibull survival analysis adjusted for covariates was performed to calculate the risk of mortality associated with the biomarkers, and C-statistics was used to assess their added predictive value.

RESULTS

During follow-up, 38 of the 431 participants died. Participants with high CRP, eosinophil count <2%, hypoalbuminemia and hypovitaminosis D had worse baseline FEV1 and subsequently higher mortality compared to controls. In adjusted analysis, increasing CRP [hazard ratio (HR): 4.45, 95% CI: 1.91-10.37] and neutrophil count (HR: 1.07, 95% CI: 1.03-1.11) as well as decreasing eosinophil count (HR: 7.03, 95% CI: 2.05-24.01) were associated with an increased risk of mortality. The addition of CRP with eosinophil and/or neutrophil count significantly improved a base model for the prediction of mortality which included age, gender, race/ethnicity, body mass index, smoking, poverty income ratio, asthma, diabetes, hypertension and history of stroke or myocardial infarction.

CONCLUSION

High CRP and neutrophils as well as low eosinophils are predictive of poor COPD prognosis. They also add significant value to prediction models of mortality in COPD.

The levels of serum pro-calcitonin and high-sensitivity C-reactive protein in the early diagnosis of chronic obstructive pulmonary disease during acute exacerbation

The level of of procalcitonin (PCT) and high-sensitivity C-reactive protein (hs-CRP) in the acute exacerbation of COPD (AECOPD) was investigated. Total of 20 patients with acute exacerbation of COPD who were admitted to the Department of Respiratory Medicine, Binzhou Center Hospital in the period of October 2012 to April 2015 were enrolled in the AECOPD group. According to the color of the sputum, the patients with AECOPD were divided into purulent sputum group (n=8) and non-purulent sputum group (n=12). In addition, 15 healthy people from the outpatient medical center were also selected as healthy control group. The levels of serum PCT and hs-CRP in both groups were determined by chemiluminescence and immunoturbidimetry, respectively for the comparison analysis. The serum PCT concentration in AECOPD group was 2.07±5.57 ng/ml, while that in healthy control group was 0.21±0.17 ng/ml. Significant difference was found between serum PCT levels in the two groups (p<0.05). The serum concentration of hs-CRP in AECOPD group was 3.66±3.95 mg/l, which is significantly higher than that of the healthy control group (0.49±0.17) (p<0.001). In AECOPD group, the sensitivity of PCT, hs-CRP and white blood cell count was 75, 40 and 40%, respectively, while the specificity was 80, 100 and 100%, respectively, indicating that PCT has higher sensitivity than hs-CRP and white blood cell count (p<0.05). However, no significant difference was found in specificity among these three methods (p>0.05). PCT level of the patients in purulent sputum group was 3.72±8.80 ng/ml, while that of the patients in non-purulent sputum group was 0.97±1.06 ng/ml. The serum hs-CRP level of patients in purulent sputum group was 4.94±4.60 mg/l, while that of the patients in non-purulent sputum group was (2.80±3.38 mg/l). Both the above parameters showed no significant difference between the purulent sputum group and the non-purulent sputum group (p>0.05). In conclusion, serum PCT and hs-CRP levels can be used as auxiliary diagnosis index for acute exacerbation of COPD. Measurement of serum PCT and hs-CRP levels in patients with AECOPD may be helpful in guiding antibacterial drug therapy.

C-reactive protein level predicts mortality in COPD: a systematic review and meta-analysis

The prognostic role of baseline C-reactive protein (CRP) in chronic obstructive pulmonary disease (COPD) is controversial. In order to clarify this issue, we performed a systematic review and meta-analysis to assess the predictive effect of baseline CRP level in COPD patients. 15 eligible articles focusing on late mortality in COPD were included in our study. We performed a random-effects meta-analysis, and assessed heterogeneity and publication bias. We pooled hazard ratio (HR) estimates and their 95% confidence intervals on mortality for the comparison between the study-specific highest category of CRP level versus the lowest category. In overall analysis, elevated baseline CRP levels were significantly associated with higher mortality (HR 1.53, 95% CI 1.32-1.77, I²=68.7%, p<0.001). Similar results were observed across subgroups. However, higher mortality risk was reported in studies using a cut-off value of 3 mg·L^-1 (HR 1.61, 95% CI 1.12-2.30) and in those enrolling an Asiatic population (HR 3.51, 95% CI 1.69-7.31). Our analysis indicates that baseline high CRP level is significantly associated with higher late mortality in patients with COPD. Further prospective controlled studies are needed to confirm these data.

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.

Neutrophil CD64 as a Marker of Bacterial Infection in Acute Exacerbations of Chronic Obstructive Pulmonary Disease

Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are responsible for most mortality in patients with chronic obstructive pulmonary disease (COPD) and are caused mainly by bacterial infection. We analyzed and compared neutrophil CD64 expression (using the ratio of CD64 level in neutrophils to that in lymphocytes as an index), serum C-reactive protein (CRP), procalcitonin (PCT) levels, white blood cell (WBC) count, and neutrophil percentage among healthy subjects and patients with stable COPD or AECOPD. Compared with patients with COPD and healthy subjects, patients with AECOPD demonstrated significantly increased CD64 index, CRP, PCT, WBC count, and neutrophil percentage. Interestingly, CD64 index and PCT were both significantly higher in patients with AECOPD with positive bacterial sputum culture than those with negative culture. Furthermore, CD64 index and PCT were positively correlated in AECOPD, and there was also correlation between CD64 index and CRP, WBC, and neutrophil percentage. These data suggest that CD64 index is a relevant marker of bacterial infection in AECOPD. We divided patients with AECOPD into CD64-guided group and conventional treatment group. In CD64-guided group, clinicians prescribed antibiotics based on CD64 index; while in the conventional treatment group, clinicians relied on experience and clinical symptoms to determine the necessity for antibiotics. We found that the efficacy of antibiotic treatment in CD64-guided group was significantly improved compared with the conventional treatment group, including reduction of hospital stays and cost and shortened antibiotic treatment duration. Thus, the CD64 index has important diagnostic and therapeutic implications for antibiotic treatment of patients with AECOPD.

Acute exacerbations of chronic obstructive pulmonary disease are associated with decreased CD4+ & CD8+ T cells and increased growth & differentiation factor-15 (GDF-15) in peripheral blood

BACKGROUND

Although T cells, especially CD8+, have been implicated in chronic obstructive pulmonary disease (COPD) pathogenesis, their role during acute exacerbations (AE-COPD) is uncertain.

METHODS

We recruited subjects with COPD and a history of previous AE-COPD and studied them quarterly to collect blood and spontaneously expectorated sputum while stable. During exacerbations (defined by a change in symptoms plus physician diagnosis and altered medications), we collected blood and sputum before administering antibiotics or steroids. We used flow cytometry to identify leukocytes in peripheral blood, plus Luminex® analysis or ELISA to determine levels of inflammatory biomarkers in serum and sputum supernatants.

RESULTS

Of 33 enrolled subjects, 13 participated in multiple stable visits and had ≥1 AE-COPD visit, yielding 18 events with paired data. Flow cytometric analyses of peripheral blood demonstrated decreased CD4+ and CD8+ T cells during AE-COPD (both absolute and as a percentage of all leukocytes) and significantly increased granulocytes, all of which correlated significantly with serum C-reactive protein (CRP) concentrations. No change was observed in other leukocyte populations during AE-COPD, although the percentage of BDCA-1+ dendritic cells expressing the activation markers CD40 and CD86 increased. During AE-COPD, sICAM-1, sVCAM-1, IL-10, IL-15 and GDF-15 increased in serum, while in sputum supernatants, CRP and TIMP-2 increased and TIMP-1 decreased.

CONCLUSIONS

The decrease in CD4+ and CD8+ T cells (but not other lymphocyte subsets) in peripheral blood during AE-COPD may indicate T cell extravasation into inflammatory sites or organized lymphoid tissues. GDF-15, a sensitive marker of cardiopulmonary stress that in other settings independently predicts reduced long-term survival, is acutely increased in AE-COPD. These results extend the concept that AE-COPD are systemic inflammatory events to which adaptive immune mechanisms contribute.

TRIAL REGISTRATION

NCT00281216 , ClinicalTrials.gov.

Conventional, molecular methods and biomarkers molecules in detection of septicemia

Sepsis is a leading cause of morbidity and mortality in hospitalized patients worldwide and based on studies, 30–40% of all cases of severe sepsis and septic shock results from the blood stream infections (BSIs). Identifying of the disease, performing laboratory tests, and consequently treatment are factors that required for optimum management of BSIs. In addition, applying precise and immediate identification of the etiologic agent is a prerequisite for specific antibiotic therapy of pathogen and thereby decreasing mortality rates. The diagnosis of sepsis is difficult because clinical signs of sepsis often overlap with other noninfectious cases of systemic inflammation. BSIs are usually diagnosed by performing a series of techniques such as blood cultures, polymerase chain reaction-based methods, and biomarkers of sepsis. Extremely time-consuming even to take up to several days is a major limitation of conventional methods. In addition, yielding false-negative results due to fastidious and slow-growing microorganisms and also in case of antibiotic pretreated samples are other limitations. In comparison, molecular methods are capable of examining a blood sample obtained from suspicious patient with BSI and gave the all required information to prescribing antimicrobial therapy for detected bacterial or fungal infections immediately. Because of an emergency of sepsis, new methods are being developed. In this review, we discussed about the most important sepsis diagnostic methods and numbered the advantage and disadvantage of the methods in detail.

Measurement of C-reactive protein, procalcitonin and neutrophil elastase in saliva of COPD patients and healthy controls: correlation to self-reported wellbeing parameters

BACKGROUND

Saliva is increasingly promoted as an alternative diagnostic bio-sample to blood; however its role in respiratory disease requires elucidation. Our aim was to investigate whether C-reactive protein (CRP), procalcitonin (PCT) and neutrophil elastase (NE) could be measured in unstimulated whole saliva, and to explore differences between COPD patients and controls with normal lung function. We also determined the relationship between these salivary biomarkers and self-reported COPD-relevant metrics.

METHODS

Salivary CRP, PCT and NE levels were measured at each of 3 visits over a 14-day period alongside spirometry and a daily self-assessment dairy in 143 subjects: 20 never-smokers and 25 smokers with normal spirometry; 98 COPD patients [GOLD Stage I, 16; Stage II, 32; Stage III, 39; Stage IV, 11]. Twenty-two randomly selected subjects provided simultaneous blood samples.

RESULTS

Levels of each salivary biomarker could distinguish between the above cohorts. Significant differences remained for salivary CRP and NE (p < 0.05) following adjustment for age, gender, sampling time, gum disease and total co-morbidities; but not for BMI except for salivary NE, which remained higher in smokers compared to non-smokers and stable COPD subjects (p < 0.001). Patients with acute COPD exacerbations had a median increase in all 3 salivary biomarkers (p < 0.001); CRP: median 5.74 ng/ml, [interquartile range (IQR) 2.86-12.25], PCT 0.38 ng/ml, [IQR 0.22-0.94], and NE 539 ng/ml, [IQR 112.25-1264]. In COPD patients, only salivary CRP and PCT levels correlated with breathing scores (r = 0.14, p < 0.02; r = 0.13, p < 0.03 respectively) and sputum features but not with activities of daily living. Salivary CRP and PCT concentrations strongly correlated with serum counterparts [r = 0.82, (95% CI: 0.72-0.87), p < 0.001 by Spearman's; and r = 0.53, (95% CI: 0.33-0.69), p < 0.006 respectively]; salivary NE did not.

CONCLUSIONS

CRP, PCT and NE were reliably and reproducibly measured in saliva, providing clinically-relevant information on health status in COPD; additionally NE distinguished smoking status. All 3 salivary biomarkers increased during COPD exacerbations, with CRP and PCT correlating well with patient-derived clinical metrics. These results provide the conceptual basis for further development of saliva as a viable bio-sample in COPD monitoring and exacerbation management.

Comparison of tumor markers and inflammatory biomarkers in chronic obstructive pulmonary disease (COPD) exacerbations

OBJECTIVE

The aim of the present study was: (a) to measure levels of the tumor markers, Carcinoembryonic antigen (CEA), Cancer antigen 19-9 (CA19-9), Cancer antigen 125 (CA125), Neuron specific enolase (NSE) and Cytokeratin fragments 19 (CYFRA21-1); (b) to investigate any correlation between them and the inflammatory biomarkers C-reactive protein (CRP), Erythrocyte sedimentation rate (ESR) and white blood cells count (WBC), in patients with chronic obstructive pulmonary disease (COPD) exacerbation, who belong in groups of severity C and D, as classified by the Global Initiative for Chronic Obstructive Lung Disease (GOLD); (c) and finally, to compare these results in these two groups.

MATERIAL AND METHODS

Fifty-two patients with COPD exacerbation [35 male/17 female, mean age (± SD) 68.3 ± 6.4 years] were the study subjects, and were classified in severity groups C (n = 27) and D (n = 25), based on the spirometric classification, the number of exacerbations in the preceding year and the assessment of their symptoms by GOLD. Results. CEA and CA125 were increased in group D. In group C, there was a significant correlation between CRP and CA125 (p = 0.05). In group D, there was a significant correlation between WBC and NSE (p = 0.02), between CRP and CA19-9 (p = 0.02) and NSE (p < 0.001), and between the ESR and NSE (p = 0.03). CA125 (p = 0.01) and CA19-9 (p = 0.01) were significantly higher in group D compared to group C. In contrast, there was no significant difference in two groups for NSE, CEA and CYFRA21-1.

CONCLUSION

Certain tumor markers were increased and were associated with increased levels of inflammatory biomarkers and with the disease severity. Inflammation might have a key pathogenetic role linking the above tumor markers with the severity of COPD.

Comparison of diagnostic values of procalcitonin, C-reactive protein and blood neutrophil/lymphocyte ratio levels in predicting bacterial infection in hospitalized patients with acute exacerbations of COPD

BACKGROUND

Viral or bacterial upper respiratory infections are the most common cause of acute exacerbation of chronic obstructive pulmonary disease (AECOPD). Based on available data, no reliable parameter has been presented to distinguish between bacterial and nonbacterial exacerbations. Therefore, we compared the diagnostic value of procalcitonin (PCT) level, which is a newer marker for predicting bacterial infections in patients with AECOPD, to routine parameters such as C-reactive protein (CRP) levels and the neutrophil/lymphocyte (N/L) ratio.

METHODS

This study included all consecutive patients who were admitted for a diagnosis of AECOPD between January 1 and March 31, 2014. PCT, CRP, and the N/L ratio were assessed in addition to cultures from tracheal aspirates or sputum on the first day of admission. Patients with a pneumonic infiltration on chest radiographs, or an extrapulmonary infection focus, or whose blood samples were not obtained for PCT and/or CRP at the same time as sputum culture were excluded from the study.

RESULTS

A total of 77 patients were included with a mean age of 71.7 ± 9.5 years. Bacteria were isolated in 37.4 % of the patients. Mean PCT levels were significantly higher in patients with positive sputum cultures than in patients with negative sputum cultures. The cut-off values for PCT, CRP, and the N/L ratio for predicting a bacterial infection were 0.40 ng/mL, 91.50 mg/L, and 11.5, respectively; sensitivity was 61, 54, and 61 % respectively; specificity was 67, 52, and 58 %, respectively; and the area under the curve (AUC) values were 0.64, 0.52, and 0.58, respectively. The AUC value of PCT was significantly better for predicting bacterial infection compared with the CRP level or the N/L ratio (p = 0.042).

CONCLUSION

PCT was better than CRP and the N/L ratio for predicting a bacterial infection in hospitalized patients with AECOPD. However, we find PCT not so reliable in predicting bacterial infection in AECOPD due to sensitivity and specificity of less than 80 % and a low AUC value.

Association of serum interleukin-27 with the exacerbation of chronic obstructive pulmonary disease

We have previously demonstrated that chronic obstructive pulmonary disease (COPD) patients who do not have Siglec‐14 are less prone to exacerbation of the disease. Siglec‐14 is a myeloid cell protein that recognizes bacteria and triggers inflammatory responses. Therefore, soluble mediators secreted by myeloid cells responding to Siglec‐14 engagement could be involved in the pathogenesis of exacerbation and could potentially be utilized as biomarkers of exacerbation. To find out, we sought genes specifically induced in Siglec‐14⁺ myeloid cells and evaluated their utility as biomarkers of COPD exacerbation. Using DNA microarray, we compared gene expression levels in Siglec‐14⁺ and control myeloid cell lines stimulated with or without nontypeable Haemophilus influenzae to select genes that were specifically induced in Siglec‐14⁺ cells. The expressions of several cytokine and chemokine genes were specifically induced in Siglec‐14⁺ cells. The concentrations of seven gene products were analyzed by multiplex bead array assays in paired COPD patient sera (n = 39) collected during exacerbation and stable disease states. Those gene products that increased during exacerbation were further tested using an independent set (n = 32) of paired patient sera. Serum concentration of interleukin‐27 (IL‐27) was elevated during exacerbation (discovery set: P = 0.0472; verification set: P = 0.0428; combined: P = 0.0104; one‐sided Wilcoxon matched‐pairs signed‐rank test), particularly in exacerbations accompanied with sputum purulence and in exacerbations lasting more than a week. We concluded that IL‐27 might be mechanistically involved in the exacerbation of COPD and could potentially serve as a systemic biomarker of exacerbation.

e12069

Chronic obstructive pulmonary disease (COPD) patients who do not have Siglec‐14 (a myeloid cell protein that triggers inflammatory responses) are less prone to exacerbation of the disease. We tested whether soluble mediators secreted by myeloid cells responding to Siglec‐14 engagement could be utilized as biomarkers of exacerbation, and found serum concentration of interleukin‐27 (IL‐27) was elevated during exacerbation, particularly in exacerbations accompanied with sputum purulence. We concluded that IL‐27 might be mechanistically involved in the exacerbation of COPD and could potentially serve as a systemic biomarker of exacerbation.

Hospitalisations due to exacerbation of asthma and COPD

BACKGROUND

Patients with exacerbation of asthma and COPD often need instant treatment, and acute hospitalisation may be necessary. The aim of the study was to determine what sort of contact patients had with doctors, and what sort of treatment they received immediately prior to hospitalisation due to exacerbation.

MATERIAL AND METHOD

A questionnaire was distributed to patients aged over 18 who were hospitalised because of asthma or COPD exacerbation in Helgeland Hospital and the University Hospital of North Norway, Tromsø, between January 2010 and January 2011. The patients answered questions on the duration of the exacerbation, their contact with doctors and their medical treatment prior to hospitalisation.

RESULTS

Data received from 100 of the 122 patients were analysed. The median duration of illness prior to the first contact with a doctor was four days. 52 of the patients had contacted their primary doctor first, 40 contacted A&E first, while eight contacted the hospital directly. The first contact with a doctor resulted in the hospitalisation of 56 patients: 21 (40 %) of those who contacted their primary doctor and 26 (70 %) of those who contacted A&E. 41 patients were hospitalised without being clinically examined by the admitting doctor the same day, 32 after a telephone consultation with their primary doctor or an A&E doctor. Patients aged over 70 were more frequently admitted without a clinical examination, as were patients who had been hospitalised previously.

INTERPRETATION

Patients with asthma or COPD exacerbation are often hospitalised directly after a telephone consultation with their primary doctor or an A&E doctor.

Efficacy of low molecular weight heparin in patients with acute exacerbation of chronic obstructive pulmonary disease receiving ventilatory support

INTRODUCTION

Severe and acute exacerbation of chronic obstructive pulmonary disease (COPD) is associated with a high mortality. Since COPD is an airway inflammatory disease, and heparin has shown anti-inflammatory effects in previous studies, we evaluated the clinical effect of low molecular weight heparin (LMWH; nadroparin) in COPD patients admitted into the hospital due to acute exacerbations.

METHODS

Sixty-six patients admitted to the intensive care unit (ICU) were randomly divided into control group (n = 33) and LMWH group (n = 33). The control group received conventional treatment, including oxygen therapy (non-invasive or conventional mechanical ventilation), anti-infection, atomization expectorant, spasmolysis, anti-asthmatics, and nutritional support. The LMWH group received the same treatment plus LMWH for 1 week. The levels of plasma C-reactive protein, interleukin-6, and fibrinogen were measured. The main outcomes were duration of mechanical ventilation, length of ICU stay, and hospital stay.

RESULTS

There were no significant differences between the groups with respect to demographics, severity of illness, and gas exchange variables. The levels of plasma C-reactive protein, interleukin-6, and fibrinogen were significantly decreased in the LMWH group. LMWH significantly reduced the mean duration of mechanical ventilation (6.6 days vs. 3.8 days; p < 0.01), the length of ICU stay (8.5 days vs. 5.6 days; p < 0.01) and hospital stay (14.3 days vs. 11.3 days; p < 0.01).

CONCLUSIONS

The addition of LMWH to standard therapy benefits COPD patients with acute exacerbation.

Mechanisms and impact of the frequent exacerbator phenotype in chronic obstructive pulmonary disease

Exacerbations of chronic obstructive pulmonary disease (COPD) are important events that carry significant consequences for patients. Some patients experience frequent exacerbations, and are now recognized as a distinct clinical subgroup, the 'frequent exacerbator' phenotype. This is relatively stable over time, occurs across disease severity, and is associated with poorer health outcomes. These patients are therefore a priority for research and treatment. The pathophysiology underlying the frequent exacerbator phenotype is complex, with increased airway and systemic inflammation, dynamic lung hyperinflation, changes in lower airway bacterial colonization and a possible increased susceptibility to viral infection. Frequent exacerbators are also at increased risk from comorbid extrapulmonary diseases including cardiovascular disease, gastroesophageal reflux, depression, osteoporosis and cognitive impairment. Overall these patients have poorer health status, accelerated forced expiratory volume over 1 s (FEV1) decline, worsened quality of life, and increased hospital admissions and mortality, contributing to increased exacerbation susceptibility and perpetuation of the frequent exacerbator phenotype. This review article sets out the definition and importance of the frequent exacerbator phenotype, with a detailed examination of its pathophysiology, impact and interaction with other comorbidities.

Pancreatic stone protein predicts positive sputum bacteriology in exacerbations of COPD

BACKGROUND

Pancreatic stone protein/regenerating protein (PSP/reg) serum levels are supposed to be increased in bacterial inflammation. PSP/reg levels also might be useful, therefore, as a predictor of bacterial infection in COPD.

METHODS

Two hundred consecutive patients presenting to the ED due to acute exacerbation of COPD were prospectively assessed. Patients were evaluated based on clinical, laboratory, and lung functional parameters at admission (exacerbation) and after short-term follow-up (14-21 days). PSP/reg serum values were measured by a newly developed enzyme-linked immunosorbent assay.

RESULTS

PSP/reg levels were elevated in subjects with COPD exacerbation (23.8 ng/mL; 95% CI, 17.1-32.7) when compared with those with stable disease (19.1 ng/mL; 95% CI, 14.1-30.4; P 5 .03) and healthy control subjects (14.0 ng/mL; 95% CI , 12.0-19.0; P , .01). Higher PSP/reg values were observed in exacerbations with positive sputum bacteriology compared with those with negative sputum bacteriology (26.1 ng/mL [95% CI, 19.2-38.1] vs 20.8 ng/mL [95% CI , 15.6-27.2]; P , .01). Multivariate regression analysis revealed PSP/reg level as an independent predictor of positive sputum bacteriology. A combination of a PSP/reg cutoff value of . 33.9 ng/mL and presence of discolored sputum had a specificity of 97% to identify patients with pathogenic bacteria on sputum culture. In contrast, PSP/reg levels , 18.4 ng/mL and nonpurulent sputum ruled out positive bacterial sputum culture (sensitivity, 92%). In survival analysis, high PSP/reg levels at hospital admission were associated with increased 2-year mortality.

CONCLUSIONS

Serum PSP/reg level might represent a promising new biomarker to identify bacterial etiology of COPD exacerbation.

Effect of exposure to solid wastes in relation to employment duration on some important markers of health and disease in waste management workers of Ogun State in southwest Nigeria

Waste management workers (WMWs) around the world are at risk of work-related health disorders. The influence of employment duration on individuals occupationally exposed to solid waste was investigated in this study. The study comprised (n = 280) 180 WMWs and 100 controls. Employment duration was obtained from questionnaire survey and categorized into three groups: group I (0.5-2 years), group II (>2-4 years) and group III (>4-6 years). Blood sample (10 ml) was collected from the antecubital vein of subjects for analysis. WMWs exhibited significantly (p < 0.001) elevated inflammatory markers (erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and ceruloplasmin (Cp)) relative to control. While Cp increased, ESR and CRP decreased with increasing WMWs' employment duration. Alteration in oxidant/antioxidant markers was characterized by significant (p < 0.001) decrease in ferric-reducing ability of plasma (FRAP) and catalase activity together with marked (p < 0.01) elevation of thiobarbituric acid reactive substances (TBARS) and uric acid (UA). TBARS, UA and FRAP increased while catalase decreased with WMWs' employment duration. In addition, WMWs exhibited significantly (p < 0.01) elevated immunoglobulin A (IgA) and IgG, which also increased and decreased, respectively, with job duration. The significantly (p < 0.01) decreased haemoglobin and haematocrit levels as well as the significantly (p < 0.001) elevated total leukocytes in WMWs increased with employment duration. Alanine aminotransferase increased and albumin decreased significantly (p < 0.05) in WMWs, and these changes also increased and decreased, respectively, with job duration. Data suggest that levels of alteration of important systemic markers of health/disease are related to WMWs' employment or exposure duration.

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.

New approaches to sepsis: molecular diagnostics and biomarkers

Sepsis is among the most common causes of death in hospitals. It arises from the host response to infection. Currently, diagnosis relies on nonspecific physiological criteria and culture-based pathogen detection. This results in diagnostic uncertainty, therapeutic delays, the mis- and overuse of antibiotics, and the failure to identify patients who might benefit from immunomodulatory therapies. There is a need for new sepsis biomarkers that can aid in therapeutic decision making and add information about screening, diagnosis, risk stratification, and monitoring of the response to therapy. The host response involves hundreds of mediators and single molecules, many of which have been proposed as biomarkers. It is, however, unlikely that one single biomarker is able to satisfy all the needs and expectations for sepsis research and management. Among biomarkers that are measurable by assays approved for clinical use, procalcitonin (PCT) has shown some usefulness as an infection marker and for antibiotic stewardship. Other possible new approaches consist of molecular strategies to improve pathogen detection and molecular diagnostics and prognostics based on transcriptomic, proteomic, or metabolic profiling. Novel approaches to sepsis promise to transform sepsis from a physiologic syndrome into a group of distinct biochemical disorders and help in the development of better diagnostic tools and effective adjunctive sepsis therapies.

Impact of chronic obstructive pulmonary diseases on outcomes and hospital days after percutaneous coronary intervention

Chronic obstructive pulmonary disease (COPD) is common in patients undergoing percutaneous coronary intervention (PCI), but the impact of COPD on outcomes after PCI has received limited attention. Consecutive patients with coronary heart disease (n = 5155) undergoing PCI were enrolled in this study; 645 patients (73% men) aged 68.4 ± 13.2 years had COPD and 4510 patients (71% men) aged 64.7 ± 12.1 years did not. During the in-hospital period after PCI, the patients with COPD experienced a significantly higher incidence of angina (P < .001), arrhythmias (P < .001), and composite major adverse cardiac events (MACEs; P < .001) and longer hospital stay (P < .001) than those without COPD. Additionally, severity of COPD (measured by pulmonary function tests) was associated with increased composite MACE (P < .001) and hospital stay (P < .001) after PCI. In conclusion, COPD is associated with significantly increased composite MACE and hospital stay in patients after PCI. Increasing severity of COPD is associated with increased composite MACE and hospital stay after PCI.

Biomarkers in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a complex disease with multiple phenotypes that cannot be identified through measurement of lung function alone. The importance of COPD risk assessment, phenotype identification, and diagnosis of exacerbation magnify the need for validated biomarkers in COPD. A large number of potential biomarkers have already been assessed and some appear promising, in particular fibrinogen, which is likely to be the first COPD biomarker presented to the Food and Drug Administration for qualification in the drug approval process. Blood fibrinogen and c-reactive protein (CRP) have been associated with the presence of COPD and, in some instances, future risk of developing COPD in targeted populations. Sputum neutrophil counts have been used preliminarily as biomarkers of favorable response to therapy in COPD, but use in clinical settings may be limited. Other potential blood biomarkers include pulmonary and activation-regulated chemokine (PARC/CCL-18) and the clara cell secretory protein 16 (CC-16). Integrative indices, such as the BODE index, provide a framework to determine prognosis, predict outcome, and may be responsive to therapeutic interventions. Computed tomography provides a means to assess phenotypes and identify the relative extents of small airways disease and emphysema, which themselves may inform prognosis and therapeutic decision making. Fibrinogen and other markers of systemic inflammation are elevated in the context of acute COPD exacerbations and may also identify those at risk of accelerated lung function decline and hospitalization. So far, no single biomarker in COPD warrants wide acceptance emphasizing the need for future investigation of biomarkers in large-scale longitudinal studies.

A unique protein profile of peripheral neutrophils from COPD patients does not reflect cytokine-induced protein profiles of neutrophils in vitro

Background

Inflammation, both local and systemic, is a hallmark of chronic obstructive pulmonary disease (COPD). Inflammatory mediators such as TNFα and GM-CSF are secreted by lung epithelium, alveolar macrophages and other inflammatory cells and are thought to be important contributors in the pathogenesis of COPD. Indeed, neutrophils are activated by these cytokines and these cells are one of the major inflammatory cell types recruited to the pulmonary compartment of COPD patients. Furthermore, these inflammatory mediators are found in the peripheral blood of COPD patients and, therefore, we hypothesized that TNFα/GM-CSF-induced protein profiles can be found in peripheral neutrophils of COPD patients.

Methods

Using fluorescence 2-dimensional difference gel electrophoresis we investigated differentially regulated proteins in peripheral neutrophils from COPD patients and healthy age-matched control subjects. Furthermore, protein profiles from COPD patients were compared with those of neutrophils of healthy age-matched controls that were stimulated with TNFα and/or GM-CSF in vitro. Protein gels were compared using DeCyder 7.0 software.

Results

We identified 7 significantly regulated protein spots between peripheral neutrophils from COPD patients and age-matched healthy control subjects. Stimulation of peripheral neutrophils with TNFα, GM-CSF or TNFα + GM-CSF in vitro resulted in 13, 20 and 22 regulated protein spots, respectively. However, these cytokine-induced protein differences did not correspond with the protein differences found in neutrophils from COPD patients.

Conclusion

These results show that neutrophils from COPD patients have a unique protein profile compared to neutrophils from healthy age-matched controls. Furthermore, the neutrophil profiles of COPD patients do not reflect putative dominant signals induced by TNFα, GM-CSF or their combination. Our results indicate that systemic neutrophil responses in COPD patients are caused by a unique but subtle interplay between multiple inflammatory signals.

The Effects of Inhaled Steroid and Theophylline on Systemic Inflammation in Copd

Chronic obstructive pulmonary disease (COPD) is a systemic disease characterized by chronic, progressive airflow limitation and airway inflammation. In this study, our aim is to compare the effects of inhaled corticosteroids and theophylline on systemic inflammatory markers in COPD. Twenty-nine moderate to severe COPD patients were randomly separated into two groups. In Group 1, inhaled corticosteroids (fluticasone propionate, 1000 meg/day) were added to regular bronchodilator therapy for 8 weeks, and theophylline (400mg/day) was added in Group 2. Pulmonary function tests were performed and serum CRP, TNF-α, and IL-6 levels were measured before and after treatment. There was a statistically significant decrease in serum CRP levels in both groups following treatment (ICS group 1.06±1.2 vs 0.49±0.22 mg/dl p< 0.05; THEO group 1.66±2.23 vs 0.59±0.35 mg/dl p< 0.05). There was a significant reduction in serum TNF-α levels in the THEO group (3.82±3.44 vs 1.89±1.33 pg/ml p< 0.05). There was no significant change in IL-6 level following treatment in either group. There was a significant increase in FEV1 in the ICS group while a non-significant increase was noted in the THEO group following treatment. It has been suggested that both ICS and THEO could be used as an anti-inflammatory agent in the treatment of COPD. Furthermore, the measurement of serum inflammatory markers is an easy and non-invasive method for the determination and follow-up of systemic inflammation in COPD. Further studies including larger patient population are needed.

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.

The differences of eosinophil- and neutrophil-related inflammation in elderly allergic and non-allergic chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a common disease in the elderly population and is characterized by airway inflammation. Whether it is a progressive condition resulting from allergic inflammation or a distinct condition involving a pathogen-induced reaction remains unclear.

OBJECTIVES

To determine the role of allergic inflammation in the pathogenesis of elderly COPD.

METHODS

A total of 63 elderly adults (21 mite-allergic COPD patients, 29 non-allergic COPD patients, and 13 normal controls) were recruited in this study. The serum-specific IgE for mites, level of interleukin-5 (IL-5), IL-8, leptin, adiponectin, regulated upon activation normal T cell expressed and secreted (RANTES), growth-related oncogene-α (GRO-α), vitamin E, and glutathione (GSH) were determined.

RESULTS

The serum levels of GRO-α in patients with COPD were higher in comparison to normal controls (105.8 ± 32.7 vs. 7.5 ± 7.5 pg/mL, p= .021). Compared to patients with non-allergic COPD, patients with mite allergies had a higher serum level of IL-8 (63.2 ± 12.6 vs. 35.0 ± 8.2 pg/mL, p= .022). Although both IL-5 and RANTES levels were increased in COPD patients, there were no significant differences between allergic and non-allergic COPD. There were also no differences in serum levels of leptin, adiponectin, vitamin E, and GSH between COPD patients and normal controls.

CONCLUSIONS

The increased serum levels of GRO-α indicate that it may have potential as a candidate biomarker for elderly COPD patients. There was no difference of eosinophils-related chemokines in allergic and non-allergic COPD. These results indicated that both adipokines and eosinophil-related chemokines only play trivial roles in the pathogenesis of COPD.

Procalcitonin vs C-reactive protein as predictive markers of response to antibiotic therapy in acute exacerbations of COPD

BACKGROUND

Rational prescription of antibiotics in acute exacerbations of COPD (AECOPD) requires predictive markers. We aimed to analyze whether markers of systemic inflammation can predict response to antibiotics in AECOPD.

METHODS

We used data from 243 exacerbations out of 205 patients from a placebo-controlled trial on doxycycline in addition to systemic corticosteroids for AECOPD. Clinical and microbiologic response, serum C-reactive protein (CRP) level (cutoffs 5 and 50 mg/L), and serum procalcitonin level (PCT) (cutoffs 0.1 and 0.25 μg) were assessed.

RESULTS

Potential bacterial pathogens were identified in the majority of exacerbations (58%). We found a modest positive correlation between PCT and CRP (r = 0.46, P < .001). The majority of patients (75%) had low PCT levels, with mostly elevated CRP levels. Although CRP levels were higher in the presence of bacteria (median, 33.0 mg/L [interquartile range, 9.75-88.25] vs 17 mg/L [interquartile range, 5.0-61.0] [P = .004]), PCT levels were similar. PCT and CRP performed similarly as markers of clinical success, and we found a clinical success rate of 90% in patients with CRP ≤ 5 mg/L. A significant effect of doxycycline was observed in patients with a PCT level < .1 μg/L (treatment effect, 18.4%; P = .003). A gradually increasing treatment effect of antibiotics (6%, 10%, and 18%), although not significant, was found for patients with CRP values of ≤ 5, 6-50, and > 50 mg/L, respectively.

CONCLUSIONS

Contrary to the current literature, this study suggests that patients with low PCT values do benefit from antibiotics. CRP might be a more valuable marker in these patients.

Prevalence and prognosis of chronic obstructive pulmonary disease among 8167 Middle Eastern patients with acute coronary syndrome

BACKGROUND

The purpose of this study was to report the prevalence and the significance of clinically recognized chronic obstructive pulmonary disease (COPD) during acute coronary syndrome (ACS).

HYPOTHESIS

COPD in patients with ACS is associated with worse outcome.

METHODS

Data were derived from a prospective, multicenter, multinational study of 8167 consecutive patients hospitalized with ACS from February to June 2007 in 6 Middle Eastern countries. Data were analyzed according to the presence or absence of COPD. Demographic, management, and in-hospital outcomes were compared.

RESULTS

The prevalence of COPD was 5.3%. When compared with non-COPD patients, COPD patients were older and more likely to have diabetes, hypertension, and dyslipidemia. Atypical presentations were more common in COPD patients (P = 0.001). COPD patients were less likely to be treated with thrombolytic therapy (P = 0.001), beta-blockers (P = 0.001), and glycoprotein IIb/IIIa inhibitors, and more likely to receive angiotensin-converting enzyme (ACE) inhibitors. Although there was no difference in in-hospital mortality between the 2 groups, patients with COPD were more likely to have heart failure (P = 0.001). Despite the fact that COPD patients with ST-segment elevation myocardial infarction were less likely to receive thrombolytic therapy, they suffered more bleeding complications (2.8% vs 1%, P = 0.04), resulting in prolonged hospitalization. COPD was not an independent predictor of increased in-hospital mortality.

CONCLUSIONS

In this large cohort of patients with ACS, the prevalence of COPD was 5.3%. Atypical presentation is common among COPD patients, and this may result in delayed therapy. ACS in COPD patients was associated with higher risk of heart failure and major bleeding complications without increased risk of in-hospital mortality.

Antibiotics in addition to systemic corticosteroids for acute exacerbations of chronic obstructive pulmonary disease

RATIONALE

The role of antibiotics in acute exacerbations is controversial and their efficacy when added to systemic corticosteroids is unknown.

OBJECTIVES

We conducted a randomized, placebo-controlled trial to determine the effects of doxycycline in addition to corticosteroids on clinical outcome, microbiological outcome, lung function, and systemic inflammation in patients hospitalized with an acute exacerbation of chronic obstructive pulmonary disease.

METHODS

Of 223 patients, we enrolled 265 exacerbations defined on the basis of increased dyspnea and increased sputum volume with or without increased sputum purulence. Patients received 200 mg of oral doxycycline or matching placebo for 7 days in addition to systemic corticosteroids. Clinical and microbiological response, time to treatment failure, lung function, symptom scores, and serum C-reactive protein were assessed.

MEASUREMENTS AND MAIN RESULTS

On Day 30, clinical success was similar in intention-to-treat patients (odds ratio, 1.3; 95% confidence interval, 0.8 to 2.0) and per-protocol patients. Doxycycline showed superiority over placebo in terms of clinical success on Day 10 in intention-to-treat patients (odds ratio, 1.9; 95% confidence interval, 1.1 to 3.2), but not in per-protocol patients. Doxycycline was also superior in terms of clinical cure on Day 10, microbiological outcome, use of open label antibiotics, and symptoms. There was no interaction between the treatment effect and any of the subgroup variables (lung function, type of exacerbation, serum C-reactive protein, and bacterial presence).

CONCLUSIONS

Although equivalent to placebo in terms of clinical success on Day 30, doxycycline showed superiority in terms of clinical success and clinical cure on Day 10, microbiological success, the use of open label antibiotics, and symptoms. Clinical trial registered with www.clinicaltrials.gov (NCT00170222).

C-reactive protein and copeptin: prognostic predictors in chronic obstructive pulmonary disease exacerbations

PURPOSE OF REVIEW

Acute exacerbation of chronic obstructive pulmonary disease (COPD) is a natural event in the course of COPD and remains a major cause of morbidity and mortality associated with this disease. Clinical criteria that define an acute exacerbation are subjective and open for debate. Identifying biomarkers that would be easily measured and followed in patients with acute exacerbation of COPD seems to be highly attractive. The aim of this review is to assess the role of biomarkers, C-reactive protein (CRP) and copeptin, as prognostic predictors in COPD exacerbations.

RECENT FINDINGS

Many pulmonary biomarkers have been extensively studied in the recent years. CRP and copeptin have gained particular interest. Recent data suggest that CRP is elevated during an acute exacerbation of COPD but CRP alone is neither sensitive nor specific in predicting clinical severity or outcome. Copeptin increases during acute exacerbation of COPD and may correlate with disease severity.

SUMMARY

Further studies are needed to determine the role of CRP and copeptin as biomarkers that aid in diagnosis and clinical outcome in acute exacerbation of COPD.

Metallic elements in exhaled breath condensate and serum of patients with exacerbation of chronic obstructive pulmonary disease

Biomarkers in exacerbated chronic obstructive pulmonary disease may be useful in aiding diagnosis, defining specific phenotypes of disease, monitoring the disease and evaluating the effects of drugs. The aim of this study was the characterization of metallic elements in exhaled breath condensate and serum as novel biomarkers of exposure and susceptibility in exacerbated chronic obstructive pulmonary disease using reference analytical techniques. C-Reactive protein and procalcitonin were assessed as previously validated diagnostic and prognostic biomarkers which have been associated with disease exacerbation, thus useful as a basis of comparison with metal levels. Exhaled breath condensate and serum were obtained in 28 patients at the beginning of an episode of disease exacerbation and when they recovered. Trace elements and toxic metals were measured by inductively coupled plasma-mass spectrometry. Serum biomarkers were measured by immunoassay. Exhaled manganese and magnesium levels were influenced by exacerbation of chronic obstructive pulmonary disease, an increase in their concentrations--respectively by 20 and 50%--being observed at exacerbation in comparison with values obtained at recovery; serum elemental composition was not modified by exacerbation; serum levels of C-reactive protein and procalcitonin at exacerbation were higher than values at recovery. In outpatients who experienced a mild-moderate chronic obstructive pulmonary disease exacerbation, manganese and magnesium levels in exhaled breath condensate are elevated at admission in comparison with values at recovery, whereas no other changes were observed in metallic elements at both the pulmonary and systemic level.

C-reactive protein and other predictors of poor outcome in patients hospitalized with exacerbations of chronic obstructive pulmonary disease

BACKGROUND AND OBJECTIVE

CRP is elevated in patients with acute exacerbations of COPD (AECOPD), but there is little information on whether this biomarker can help to identify adverse short-term clinical outcomes.

METHODS

A 6-month prospective study of all patients with AECOPD requiring hospital admission. Clinical, laboratory (including plasma CRP levels at admission) and functional data were recorded. The outcome variable (the adverse outcome) consisted of: (i) death in hospital or within 15 days of discharge, (ii) transfer to the intensive care unit, or (iii) development of acute heart failure during hospitalization.

RESULTS

Data from 147 patients with a total of 160 admissions were recorded. During follow up, 38 (23.7%) adverse outcomes were observed, including 13 (8.8%) and 8 (5.4%) patients who died during hospitalization or within 15 days of discharge, respectively. CRP at a level of 50 mg/L was related to an adverse outcome (OR 4.9, 95% CI: 1.92-12.6, P < 0.01), although by itself it was neither sensitive nor specific (area under the receiver operating characteristic curve (AUC) 0.69, 95% CI: 0.60-0.77). However, a risk score derived from the combination of CRP with other variables, such as 'current smoker', 'at least two comorbidities' and 'confusion,' at admission showed good predictive ability to identify an adverse outcome (AUC of 0.80, 95% CI: 0.72-0.88).

CONCLUSIONS

Plasma CRP in combination with other variables obtained at admission may assist identification of high-risk patients with AECOPD.