Serum biomarkers and outcomes in patients with moderate COPD: a substudy of the randomised SUMMIT trial

The AGE-RAGE axis associates with chronic pulmonary diseases and smoking in the Rotterdam study

BACKGROUND

Chronic obstructive pulmonary disease (COPD) and asthma associate with high morbidity and mortality. High levels of advanced glycation end products (AGEs) were found in tissue and plasma of COPD patients but their role in COPD and asthma is unclear.

METHODS

In the Rotterdam Study (n = 2577), AGEs (by skin autofluorescence (SAF)), FEV1 and lung diffusing capacity (DLCOc and DLCOc /alveolar volume [VA]) were measured. Associations of SAF with asthma, COPD, GOLD stage, and lung function were analyzed using logistic and linear regression adjusted for covariates, followed by interaction and stratification analyses. sRAGE and EN-RAGE associations with COPD prevalence were analyzed by logistic regression.

RESULTS

SAF associated with COPD prevalence (OR = 1.299 [1.060, 1.591]) but not when adjusted for smoking (OR = 1.106 [0.89, 1.363]). SAF associated with FEV1% predicted (β=-3.384 [-4.877, -1.892]), DLCOc (β=-0.212 [-0.327, -0.097]) and GOLD stage (OR = 4.073, p = 0.001, stage 3&4 versus 1). Stratified, the association between SAF and FEV1%predicted was stronger in COPD (β=-6.362 [-9.055, -3.670]) than non-COPD (β=-1.712 [-3.306, -0.118]). Association of SAF with DLCOc and DLCOc/VA were confined to COPD (β=-0.550 [-0.909, -0.191]; β=-0.065 [-0.117, -0.014] respectively). SAF interacted with former smoking and COPD prevalence for associations with lung function. Lower sRAGE and higher EN-RAGE associated with COPD prevalence (OR = 0.575[0.354, 0.931]; OR = 1.778[1.142, 2.768], respectively).

CONCLUSIONS

Associations between SAF, lung function and COPD prevalence were strongly influenced by smoking. SAF associated with COPD severity and its association with lung function was more prominent within COPD. These results fuel further research into interrelations and causality between SAF, smoking and COPD.

TAKE-HOME MESSAGE

Skin AGEs associated with prevalence and severity of COPD and lung function in the general population with a stronger effect in COPD, calling for further research into interrelations and causality between SAF, smoking and COPD.

L-Arginine, as an essential amino acid, is a potential substitute for treating COPD via regulation of ROS/NLRP3/NF-κB signaling pathway

BACKGROUNDS

Chronic obstructive pulmonary disease (COPD) is a frequent and common disease in clinical respiratory medicine and its mechanism is unclear. The purpose of this study was to find the new biomarkers of COPD and elucidate its role in the pathogenesis of COPD. Analysis of metabolites in plasma of COPD patients were performed by ultra-high performance liquid chromatography (UPLC) and quadrupole time-of-flight mass spectrometry (TOF-MS). The differential metabolites were analyzed and identified by multivariate analysis between COPD patients and healthy people. The role and mechanisms of the differential biomarkers in COPD were verified with COPD rats, arginosuccinate synthetase 1 (ASS-l) KO mice and bronchial epithelial cells (BECs). Meanwhile, whether the differential biomarkers can be the potential treatment targets for COPD was also investigated. 85 differentials metabolites were identified between COPD patients and healthy people by metabonomic.

RESULTS

L-Arginine (LA) was the most obvious differential metabolite among the 85 metabolites. Compare with healthy people, the level of LA was markedly decreased in serum of COPD patients. It was found that LA had protective effects on COPD with in vivo and in vitro experiments. Silencing Ass-1, which regulates LA metabolism, and α-methy-DL-aspartic (NHLA), an Ass-1 inhibitor, canceled the protective effect of LA on COPD. The mechanism of LA in COPD was related to the inhibition of ROS/NLRP3/NF-κB signaling pathway. It was also found that exogenous LA significantly improved COPD via regulation of ROS/NLRP3/NF-κB signaling pathway. L-Arginine (LA) as a key metabolic marker is identified in COPD patients and has a protective effect on COPD via regulation of ROS/NLRP3/NF-κB signaling pathway.

CONCLUSION

LA may be a novel target for the treatment of COPD and also a potential substitute for treating COPD.

Prognostic Value of Neutrophil to Lymphocyte Ratio for Predicting 90-Day Poor Outcomes in Hospitalized Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Objective

This study aimed to evaluate the predictive value of neutrophil to lymphocyte ratio (NLR) for poor outcomes within 90-day in hospitalized patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD).

Methods

A retrospective study including 503 AECOPD patients was performed, and the subjects' clinical characteristics were collected. Binary logistic regression analysis was used to identify risk factors for 90-day poor outcomes in patients with AECOPD. Receiver-operating characteristic curves (ROC) and areas under the curves (AUC) were used to assess the ability of different biomarkers to predict the risk of 90-day mortality, readmission and re-exacerbation in patients with AECOPD.

Results

During the follow-up, 188 patients (38.4%) redeveloped exacerbations, 112 patients (22.9%) were readmitted, and 20 patients (4.1%) died directly resulted from COPD or COPD-related causes. Multivariate analysis demonstrated that age>72 years (OR: 14.817, 95% CI: 1.561-140.647), NLR>14.17 (OR: 9.611, 95% CI: 2.303-40.113), EOS<0.15% (OR: 8.621, 95% CI: 3.465-34.913) and BNP>2840ng/L (OR: 5.291, 95% CI: 1.367-20.474) at discharge were independent risk factors for 90-day mortality in AECOPD patients. NLR was the optimal biomarker for predicting 90-day mortality with an AUC of 0.802 (95% CI: 0.631-0.973). Using 14.17 as the critical value of NLR, the sensitivity was 76.7%, and the specificity was 88.9%. Compared with mortality, NLR had no significant advantage in predicting risk of short-term re-exacerbation (AUC=0.580, 95% CI:0.529-0.632, p=0.001) and readmission (AUC=0.555, 95% CI:0.497-0.614, p=0.045), with AUCs less than 0.6. In contrast, the predictive value of EOS (AUC=0.561, 95% CI:0.502-0.621, p=0.038) was slightly better than NLR in terms of readmission within 90 days. CRP did not serve as a well predictive biomarker for the risk of readmission and re-deterioration (p>0.05).

Conclusion

NLR is of great value in predicting the risk of poor outcomes, especially COPD associated mortality, in hospitalized patients with AECOPD within 90 days after discharge.

A blood and bronchoalveolar lavage protein signature of rapid FEV1 decline in smoking-associated COPD

Accelerated progression of chronic obstructive pulmonary disease (COPD) is associated with increased risks of hospitalization and death. Prognostic insights into mechanisms and markers of progression could facilitate development of disease-modifying therapies. Although individual biomarkers exhibit some predictive value, performance is modest and their univariate nature limits network-level insights. To overcome these limitations and gain insights into early pathways associated with rapid progression, we measured 1305 peripheral blood and 48 bronchoalveolar lavage proteins in individuals with COPD [n = 45, mean initial forced expiratory volume in one second (FEV1) 75.6 ± 17.4% predicted]. We applied a data-driven analysis pipeline, which enabled identification of protein signatures that predicted individuals at-risk for accelerated lung function decline (FEV1 decline ≥ 70 mL/year) ~ 6 years later, with high accuracy. Progression signatures suggested that early dysregulation in elements of the complement cascade is associated with accelerated decline. Our results propose potential biomarkers and early aberrant signaling mechanisms driving rapid progression in COPD.

Nasal biomarkers of immune function differ based on smoking and respiratory disease status

Respiratory biomarkers have the potential to identify airway injury by revealing inflammatory processes within the respiratory tract. Currently, there are no respiratory biomarkers suitable for clinical use to identify patients that warrant further diagnostic work-up, counseling, and treatment for toxic inhalant exposures or chronic airway disease. Using a novel, noninvasive method of sampling the nasal epithelial lining fluid, we aimed to investigate if nasal biomarker patterns could distinguish healthy nonsmoking adults from active smokers and those with chronic upper and lower airway disease in this exploratory study. We compared 28 immune mediators from healthy nonsmoking adults (n = 32), former smokers with COPD (n = 22), chronic rhinosinusitis (CRS) (n = 22), and smoking adults without airway disease (n = 13). Using ANOVA, multinomial logistic regressions, and weighted gene co-expression network analysis (WGCNA), we determined associations between immune mediators and each cohort. Six mediators (IL-7, IL-10, IL-13, IL-12p70, IL-15, and MCP-1) were lower among disease groups compared to healthy controls. Participants with lower levels of IL-10, IL-12p70, IL-13, and MCP-1 in the nasal fluid had a higher odds of being in the COPD or CRS group. The cluster analysis identified groups of mediators that correlated with disease status. Specifically, the cluster of IL-10, IL-12p70, and IL-13, was positively correlated with healthy and negatively correlated with COPD groups, and two clusters were correlated with active smoking. In this exploratory study, we preliminarily identified groups of nasal mucosal mediators that differed by airway disease and smoking status. Future prospective, age-matched studies that control for medication use are needed to validate these patterns and determine if nasosorption has diagnostic utility for upper and lower airway disease or injury.

Novel Applications of Biomarkers in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is an important health problem and an increasing cause of morbidity and mortality worldwide. Currently, COPD is considered a multisystem disease. Although it primarily affects the lungs, structural and functional changes occur in other organs due to systemic inflammation. It is stated that in patients with COPD, airway and systemic inflammatory markers are increased and that these markers are high are associated with a faster decline in lung functions. In recent years, numerous articles have been published on the discovery and evaluation of biomarkers in COPD. Many markers have also been studied to accurately assess COPD exacerbations and provide effective treatment. However, based on the evidence from published studies, a single molecule has not been adequately validated for broad clinical use.

Lung-Protective Effects of Lidocaine Infusion on Patients with Intermediate/ High Risk of Postoperative Pulmonary Complications: A Double-Blind Randomized Controlled Trial

Purpose

The non-local anesthetic effects of lidocaine have been widely reported, but there are still few studies on lung protection. We aimed to test the hypothesis that intravenous infusion of lidocaine exerts lung-protective effects in patients at intermediate/high risk of postoperative pulmonary complications (PPCs) on major abdominal surgery.

Patients and Methods

Patients ≥18 years, ASA II or III, with intermediate/high risk for PPCs, were included. Patients were randomly assigned into group lidocaine (received a bolus of lidocaine 1.5 mg kg⁻¹ before the induction of anesthesia, then followed by a continuous infusion of 2.0 mg kg⁻¹ h⁻¹ intraoperatively until the end of surgery) or group control (received 0.9% saline in place of lidocaine at the same time points). The incidence of PPCs within 7 postoperative days was measured, defined as a collapsed composite outcome of atelectasis, respiratory infection, pleural effusion, pneumonia, respiratory failure or acute respiratory distress syndrome (ARDS) developed within 7 postoperative days, or hospital discharge, whichever came sooner.

Results

Of 200 subjects screened, 195 patients were finally analyzed. Overall, 35.9% (70/195) patients sustained PPCs, which occurred fewer in group lidocaine 25.8% (25/97), compared with group control 45.9% (45/98) (relative risk: 0.56, 95% CI: 0.38 to 0.84; absolute risk reduction: −20.1%; P = 0.003). Considering single PPCs episode, the most common PPC in both groups was atelectasis. The atelectasis incidence was 11.3% (11/97) in group lidocaine, much lower than that in group control 29.6% (29/98) (relative risk: 0.38, 95% CI: 0.20 to 0.72; absolute risk reduction: −18.3%, P = 0.002). However, the incidences of any other PPCs episodes were similar between the two groups.

Conclusion

Intraoperative intravenous infusion lidocaine could decrease the incidence of PPCs in patients at intermediate/high risk of postoperative pulmonary complications undergoing major abdominal surgery.

Incorporating Biomarkers in COPD Management: The Research Keeps Going

Globally, chronic obstructive pulmonary disease (COPD) remains a major cause of morbidity and mortality, having a significant socioeconomic effect. Several molecular mechanisms have been related to COPD including chronic inflammation, telomere shortening, and epigenetic modifications. Nowadays, there is an increasing need for novel therapeutic approaches for the management of COPD. These treatment strategies should be based on finding the source of acute exacerbation of COPD episodes and estimating the patient’s own risk. The use of biomarkers and the measurement of their levels in conjunction with COPD exacerbation risk and disease prognosis is considered an encouraging approach. Many types of COPD biomarkers have been identified which include blood protein biomarkers, cellular biomarkers, and protease enzymes. They have been isolated from different sources including peripheral blood, sputum, bronchoalveolar fluid, exhaled air, and genetic material. However, there is still not an exclusive biomarker that is used for the evaluation of COPD but rather a combination of them, and this is attributed to disease complexity. In this review, we summarize the clinical significance of COPD-related biomarkers, their association with disease outcomes, and COPD patients’ management. Finally, we depict the various samples that are used for identifying and measuring these biomarkers.

Correlations Between Inflammatory Biomarkers in Tuberculosis-Associated Obstructive Pulmonary Disease Patients With Anxiety and Depression

Introduction

Tuberculosis-associated obstructive pulmonary disease (TOPD), anxiety, and depression are significant public health problems worldwide and their prevalence is common. These diseases interfere with physical, psychosocial, and economic well-being, resulting in unemployment, prolonged hospitalization, abstinence from working, and isolation.

Subjects and methods

This is a single-center, cross-sectional cohort, observational study conducted in a tertiary care hospital over six years to understand spirometry, laboratory profiles, as well as the impact on overall health, daily life, and perceived well-being in patients with TOPD.

Result

The sample size of the study was 73 patients. A total of 43 (58.5%) patients had depression with an average St. George's Respiratory Questionnaire for chronic obstructive pulmonary disease (SGRQ-C) score of 67.5, and 16 (21.9%) patients had anxiety with an average SGRQ-C score of 78.9. In the patients who scored higher on the Hamilton Depression Rating Scale (HAM-D), there was a significant correlation between Hamilton Anxiety Rating Scale (HAM-A) and HAM-D scores, as well as C-reactive protein (CRP) levels and WBC counts. In 16 (21.9%) of the patients with moderate to severe anxiety, there was a statistically significant negative correlation between higher HAM-A scores and lower WBC counts. Anxiety, depression, CRP level, WBC count, and serum fibrinogen did not show a significant correlation with the Global Initiative for Chronic Obstructive Lung Disease (GOLD) groups-based assessment of TOPD severity. A high serum fibrinogen level did not correlate with a high HAM-D score, nor did a high CRP level correlate with a high HAM-A score.

Conclusion

Psychiatric comorbidities like depression are associated with increased inflammation in chronic diseases like TOPD, but no definitive biomarker has been identified and further studies are required to identify suitable biomarkers.

Plasma sRAGE levels strongly associate with centrilobular emphysema assessed by HRCT scans

Background

There is a strong need for biomarkers to better characterize individuals with COPD and to take into account the heterogeneity of COPD. The blood protein sRAGE has been put forward as promising biomarker for COPD in general and emphysema in particular. Here, we measured plasma sRAGE levels using quantitative LC–MS and assessed whether the plasma sRAGE levels associate with (changes in) lung function, radiological emphysema parameters, and radiological subtypes of emphysema.

Methods

Three hundred and twenty-four COPD patients (mean FEV₁: 63%predicted) and 185 healthy controls from the COPDGene study were selected. Plasma sRAGE was measured by immunoprecipitation in 96-well plate methodology to enrich sRAGE, followed by targeted quantitative liquid chromatography-mass spectrometry. Spirometry and HRCT scans (inspiration and expiration) with a 5-year follow-up were used; both subjected to high quality control standards.

Results

Lower sRAGE values significantly associated with the presence of COPD, the severity of airflow obstruction, the severity of emphysema on HRCT, the heterogeneous distribution of emphysema, centrilobular emphysema, and 5-year progression of emphysema. However, sRAGE values did not associate with airway wall thickness or paraseptal emphysema.

Conclusions

Rather than being a general COPD biomarker, sRAGE is especially a promising biomarker for centrilobular emphysema. Follow-up studies should elucidate whether sRAGE can be used as a biomarker for other COPD phenotypes as well.

Relationships of serum CC16 levels with smoking status and lung function in COPD

BACKGROUND

The club cell secretory protein (CC16) has anti-inflammatory and antioxidant effects, and low CC16 serum levels have been associated with both risk and progression of COPD, yet the interaction between smoking and CC16 on lung function outcomes remains unknown.

METHODS

Utilizing cross-sectional data on United States veterans, CC16 serum concentrations were measured by ELISA and log transformed for analyses. Spirometry was conducted and COPD status was defined by post-bronchodilator FEV₁/FVC ratio < 0.7. Smoking measures were self-reported on questionnaire. Multivariable logistic and linear regression were employed to examine associations between CC16 levels and COPD, and lung function with adjustment for covariates. Unadjusted Pearson correlations described relationships between CC16 level and lung function measures, pack-years smoked, and years since smoking cessation.

RESULTS

The study population (N = 351) was mostly male, white, with an average age over 60 years. An interaction between CC16 and smoking status on FEV₁/FVC ratio was demonstrated among subjects with COPD (N = 245, p = 0.01). There was a positive correlation among former smokers and negative correlation among current or never smokers with COPD. Among former smokers with COPD, CC16 levels were also positively correlated with years since smoking cessation, and inversely related with pack-years smoked. Increasing CC16 levels were associated with lower odds of COPD (OR_adj = 0.36, 95% CI 0.22-0.57, P_adj < 0.0001).

CONCLUSIONS

Smoking status is an important effect modifier of CC16 relationships with lung function. Increasing serum CC16 corresponded to increases in FEV₁/FVC ratio in former smokers with COPD versus opposite relationships in current or never smokers. Additional longitudinal studies may be warranted to assess relationship of CC16 with smoking cessation on lung function among subjects with COPD.

Surfaxin attenuates PM2.5-induced airway inflammation via restoring surfactant proteins in rats exposed to cigarette smoke

Epidemiologic studies have shown that the fine particulate matter 2.5 (PM2.5) exaggerates chronic airway inflammation involving in acute exacerbation of chronic obstructive pulmonary disease (AECOPD). Surfactant proteins (SPs) decreases significantly related to airflow limitation and airway inflammation. However, how to restore the reduction of SPs levels in airway inflammation exposed to PM2.5 has not been well understood. In the present study, the SPs including SPA, SPB, SPC and SPD levels in bronchoalveolar lavage fluid (BALF) were detected from patients with stable COPD. Rats were exposed to cigarette smoke and PM2.5. After given with Surfaxin, the expression of SPs, protein kinase C (PKC) and tight junction protein (ZO-1) in lung tissue and the levels of C-reactive protein (CRP) and fibrinogen (FIB) in plasma was observed. The results showed that SPA, SPB and SPD were significantly lower than those of the control group (p < 0.01). PM2.5 aggravated smoking-induced airway inflammation and oxidative stress demonstrated by pathological changes of lung tissue and increased levels of CRP and PKC in vivo. PM2.5 decreased the expression of all the SPs and ZO-1, which could be significantly restored by Surfaxin. These findings indicate that Surfaxin protects the alveolar epithelium from PM2.5 in airway inflammation through increasing SPs.

Use of Laboratory Tests and Their Prognostic Value in Patients with Stable Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is not merely a lung disease as the name indicates. Patients with COPD experience associated complications with systemic inflammation, heart strain, muscle wasting, poor functional performance, and psychological issues. An assessment of these patients based only on lung function tests or functional capacity would be inadequate. Many studies have reported the significance and prognostic value of several laboratory tests. Troponin, C-reactive protein (CRP), hemoglobin, and carbon dioxide are older tests but compared with the newly developed tests, they are relatively inexpensive to measure and widely available. This article will review laboratory tests used for COPD and discuss their prognostic value. The laboratory tests that can identify high-risk patients will be discussed. We will explore the role of these tests in clinical practice.

A genomic approach identifies sRAGE as a putatively causal protein for asthma

BACKGROUND

Asthma is a complex respiratory condition caused by environmental and genetic factors. Although lower concentrations of the anti-inflammatory protein sRAGE have been associated with asthma in humans and mouse models, it is uncertain whether sRAGE plays a causal role in asthma.

OBJECTIVE

We designed a two-stage study of sRAGE in relation to asthma with i) association analysis in FHS participants and ii) causal inference testing using MR.

METHODS

We measured plasma levels of sRAGE and performed cross-sectional analysis to examine the association between plasma sRAGE concentration and asthma status in 6,546 FHS participants. We then used sRAGE pQTLs derived from a GWAS of plasma sRAGE levels in ∼7,000 FHS participants with UK Biobank asthma GWAS in MR to consider sRAGE as a putatively causal protein for asthma. We also performed replication MR using an externally-derived sRAGE pQTL from the INTERVAL study. Last, we conducted colocalization using cis-pQTL variants at the AGER locus with variants from the UK Biobank asthma GWAS.

RESULTS

Association analysis revealed that each 1 SD increment in sRAGE concentration was associated with a 14% lower odds of asthma in FHS participants (95% CI 0.76-0.96). MR identified sRAGE as putatively causal for and protective against asthma based on self-reported (OR [per 1 SE increment in inverse rank-normalized sRAGE]=0.97, 95% CI 0.95-0.99; p=0.005) and doctor-diagnosed asthma (OR=0.97, 95% CI 0.95-0.99; p=0.011).

CONCLUSION

Through this genomic approach, we identified sRAGE as a putatively causal, biologically important, and protective protein in relation to asthma. Functional studies in cell/animal models are needed to confirm our findings.

Lung proteomic biomarkers associated with chronic obstructive pulmonary disease

Identifying protein biomarkers for chronic obstructive pulmonary disease (COPD) has been challenging. Most previous studies have used individual proteins or preselected protein panels measured in blood samples. Mass spectrometry proteomic studies of lung tissue have been based on small sample sizes. We used mass spectrometry proteomic approaches to discover protein biomarkers from 150 lung tissue samples representing COPD cases and controls. Top COPD-associated proteins were identified based on multiple linear regression analysis with false discovery rate (FDR) < 0.05. Correlations between pairs of COPD-associated proteins were examined. Machine learning models were also evaluated to identify potential combinations of protein biomarkers related to COPD. We identified 4,407 proteins passing quality controls. Twenty-five proteins were significantly associated with COPD at FDR < 0.05, including interleukin 33, ferritin (light chain and heavy chain), and two proteins related to caveolae (CAV1 and CAVIN1). Multiple previously reported plasma protein biomarkers for COPD were not significantly associated with proteomic analysis of COPD in lung tissue, although RAGE was borderline significant. Eleven pairs of top significant proteins were highly correlated (r > 0.8), including several strongly correlated with RAGE (EHD2 and CAVIN1). Machine learning models using Random Forests with the top 5% of protein biomarkers demonstrated reasonable accuracy (0.707) and area under the curve (0.714) for COPD prediction. Mass spectrometry-based proteomic analysis of lung tissue is a promising approach for the identification of biomarkers for COPD.

From Biomarkers to Novel Therapeutic Approaches in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a heterogeneous and complex disorder. In this review, we provided a comprehensive overview of biomarkers involved in COPD, and potential novel biological therapies that may provide additional therapeutic options for COPD. The complex characteristics of COPD have made the recommendation of a generalized therapy challenging, suggesting that a tailored, personalized strategy may lead to better outcomes. Existing and unmet needs for COPD treatment support the continued development of biological therapies, including additional investigations into the potential clinical applications of this approach.

Lung function trajectory and biomarkers in the Tasmanian Longitudinal Health Study

Background and objective

Different lung function trajectories through life can lead to COPD in adulthood. This study investigated whether circulating levels of biomarkers can differentiate those with accelerated (AD) from normal decline (ND) trajectories.

Methods

The Tasmanian Longitudinal Health Study (TAHS) is a general population study that measured spirometry and followed up participants from ages 7 to 53 years. Based on their forced expiratory volume in 1 s (FEV₁) trajectories from age 7 to 53 years, this analysis included those with COPD at age 53 years (60 with AD and 94 with ND) and controls (n=720) defined as never-smokers with an average FEV₁ trajectory. Circulating levels of selected biomarkers determined at 53 and 45 years of age were compared between trajectories.

Results

Results showed that CC16 levels (an anti-inflammatory protein) were lower and C-reactive protein (CRP) (a pro-inflammatory marker) higher in the AD than in the ND trajectory. Higher CC16 levels were associated with a decreased risk of belonging to the AD trajectory (OR=0.79 (0.63-0.98) per unit increase) relative to ND trajectory. Higher CRP levels were associated with an increased risk of belonging to the AD trajectory (OR=1.07, 95% CI: 1.00-1.13, per unit increase). Levels of CC16 (area under the curve (AUC)=0.69, 95% CI: 0.56-0.81, p=0.002), CRP (AUC=0.63, 95% CI: 0.53-0.72, p=0.01) and the combination of both (AUC=0.72, 95% CI: 0.60-0.83, p<0.001) were able to discriminate between the AD and ND trajectories. Other quantified biomarkers (interleukin (IL)-4, IL-5, IL-6, IL-10 and tumour necrosis factor-α (TNF-α)) were not significantly different between AD, ND and controls.

Conclusions

Circulating levels of CRP and CC16 measured in late adulthood identify different lung function trajectories (AD versus ND) leading to COPD at age 53 years.

Clinical significance of changes in serum inflammatory factors in patients with chronic obstructive pulmonary disease and pulmonary infection

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is often accompanied by pulmonary infection, inflammatory responses, decreased immunity, and decreased lung function. The relationships among the pulmonary inflammation index (PII), lung function, and immunity in COPD patients with pulmonary infection remain unclear.

METHODS

This retrospective observational study enrolled 234 participants (patients with COPD and pulmonary infection, patients with COPD without pulmonary infection, and healthy individuals) from January 2017 to December 2019.

RESULTS

Levels of interleukin (IL)-6 were lower and levels of IL-8 were higher in patients with COPD and pulmonary infection. Levels of white blood cells (WBCs), C-reactive protein (CRP), IL-6, IL-8, tumor necrosis factor (TNF)-α and CD8+ cells were higher, while levels of CD3+ and CD4+ cells, the CD4+/CD8+ ratio, forced expiratory volume in 1 s (FEV1), FEV1 % predicted (FEV1%pred), and FEV1/forced vital capacity (FVC) (FEV1%FVC) were lower in patients with COPD and pulmonary infection. Levels of WBCs, CRP, IL-6, IL-8, and TNF-α were negatively associated with FEV1, FEV1%pred and FEV1%FVC.

CONCLUSIONS

Patients with COPD and pulmonary infection have high PIIs, decreased immunity, and poor lung function. PII is closely related to lung function and may represent a useful biomarker for the assessment of patients with COPD and pulmonary infection.

InforMing the PAthway of COPD Treatment (IMPACT) trial: fibrinogen levels predict risk of moderate or severe exacerbations

BACKGROUND

Fibrinogen is the first qualified prognostic/predictive biomarker for exacerbations in patients with chronic obstructive pulmonary disease (COPD). The IMPACT trial investigated fluticasone furoate/umeclidinium/vilanterol (FF/UMEC/VI) triple therapy versus FF/VI and UMEC/VI in patients with symptomatic COPD at risk of exacerbations. This analysis used IMPACT trial data to examine the relationship between fibrinogen levels and exacerbation outcomes in patients with COPD.

METHODS

8094 patients with a fibrinogen assessment at Week 16 were included, baseline fibrinogen data were not measured. Post hoc analyses were performed by fibrinogen quartiles and by 3.5 g/L threshold. Endpoints included on-treatment exacerbations and adverse events of special interest (AESIs).

RESULTS

Rates of moderate, moderate/severe, and severe exacerbations were higher in the highest versus lowest fibrinogen quartile (0.75, 0.92 and 0.15 vs 0.67, 0.79 and 0.10, respectively). The rate ratios (95% confidence interval [CI]) for exacerbations in patients with fibrinogen levels ≥ 3.5 g/L versus those with fibrinogen levels < 3.5 g/L were 1.03 (0.95, 1.11) for moderate exacerbations, 1.08 (1.00, 1.15) for moderate/severe exacerbations, and 1.30 (1.10, 1.54) for severe exacerbations. There was an increased risk of moderate/severe exacerbation (hazard ratio [95% CI]: highest vs lowest quartile 1.16 [1.04, 1.228]; ≥ 3.5 g/L vs < 3.5 g/L: 1.09 [1.00, 1.16]) and severe exacerbation (1.35 [1.09, 1.69]; 1.27 [1.08, 1.47], respectively) with increasing fibrinogen level. Cardiovascular AESIs were highest in patients in the highest fibrinogen quartile.

CONCLUSIONS

Rate and risk of exacerbations was higher in patients with higher fibrinogen levels. This supports the validity of fibrinogen as a predictive biomarker for COPD exacerbations, and highlights the potential use of fibrinogen as an enrichment strategy in trials examining exacerbation outcomes.

TRIAL REGISTRATION

NCT02164513.

The use of the soluble receptor for advanced glycation-end products (sRAGE) as a potential biomarker of disease risk and adverse outcomes

The soluble receptor for advanced glycation end-products (sRAGE) has been classically considered a sink for pro-inflammatory RAGE ligands and as such has been associated with protection from inflammatory stress and disease. An alternative, though not mutually exclusive view is that high levels of sRAGE in circulation reflect the overstimulation of cell surface RAGE which if persistent, lead to the amplification of pro-inflammatory processes and the exacerbation of pathological states. With these two scenarios in mind this review focuses on the potential role of sRAGE as a prospective biomarker of disease risk and adverse outcomes.

•

The prognostic value of measuring sRAGE levels in blood is subjected to debate.

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Raised sRAGE levels may result from the overstimulation of cell surface RAGE.

•

Raised sRAGE may reflect chronic inflammation and multimorbidity rather than a healthy state.

•

sRAGE is a promising biomarker of disease risk and adverse outcomes.

Systemic Cytokine Profiles of CD4+ T Lymphocytes Correlate with Clinical Features and Functional Status in Stable COPD

Aims

To evaluate the expressions of intracellular cytokines in CD4+ T lymphocytes and to investigate the correlation between biomarker expressions and clinical and functional characteristics of stable COPD patients.

Patients and Methods

Peripheral blood was collected from 36 COPD patients, and the expression of cytokines (IL-8, IL-13, IL-17, IL-6, IL-2, IL-10, and TNF-α) in T lymphocytes CD4 + was investigated. In addition, lung function, dyspnea symptoms, quality of life, vital signs, body composition, level of physical activity, peripheral muscle strength, and functional capacity were assessed.

Results

Individuals with greater bronchial obstruction present a higher proportion of CD4 + IL-2 + lymphocytes compared to individuals with less severe bronchial obstruction. We found a positive correlation between the expression of the cytokines IL-13, IL-17, IL-6, IL-2, IL-10, and TNF-α in CD4+ T lymphocytes. In addition, we found a positive correlation between CD4+ IL-10+ T lymphocytes and lower limb muscle strength and a negative correlation between CD4+ IL-8+ T lymphocytes and peripheral oxygen saturation and steps per day.

Conclusion

Systemic CD4+IL-2+, IL-8+, and IL-10+ T lymphocytes presented a correlation with clinical characteristics and functional status in stable COPD.

The AGE-RAGE Axis and RAGE Genetics in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a heterogeneous group of lung diseases limiting the airflow due to narrowing of airways, chronic bronchitis and emphysema that leads to difficulties in breathing. Chronic inflammation is another important characteristic of COPD which leads to immune cell infiltration and helps in the alveolar destruction. Pathology of COPD is driven by various environmental and genetic factors. COPD is mainly associated with the inhalation of toxic agents mainly the cigarette smoke. Receptor for advanced glycation end products (RAGE) has emerged as a pattern recognition receptor and is a multiligand receptor expressed moderately in various cells, tissues and highly in the lungs throughout life. RAGE recognizes various ligands produced by cigarette smoke and its role has been implicated in the pathogenesis of COPD. RAGE ligands have been reported to accumulate in the lungs of patients with COPD. RAGE is a membrane receptor but its truncated form i.e. soluble RAGE (sRAGE) mainly functions as a contender of RAGE and inhibits various RAGE dependent cell signalling. Among the various ligands of RAGE, advanced glycation end products (AGEs) are majorly linked with COPD. Accumulated AGE triggers downstream RAGE-AGE axis in COPD. Moreover, RAGE genetics has long been known to play a vital role in the pathology of various airway diseases including COPD and this gene contains an associated locus. A reliable biomarker is needed for the management of this disease. sRAGE has an inverse correlation with the RAGE showed its importance as a valuable marker in COPD. This review is focused on the role of RAGE, sRAGE, RAGE axis and RAGE genetics in COPD.

FEV1 is a stronger mortality predictor than FVC in patients with moderate COPD and with an increased risk for cardiovascular disease

Purpose

Chronic obstructive pulmonary disease (COPD) is one of the leading causes of death worldwide. Impaired lung function is associated with heightened risk for death, cardiovascular events, and COPD exacerbations. However, it is unclear if forced expiratory volume in one second (FEV₁) and forced vital capacity (FVC) differ in predictive value.

Patients and Methods

Data from 16,485 participants in the Study to Understand Mortality and Morbidity (SUMMIT) in COPD were analyzed. Patients were grouped into quintiles for each lung function parameter (FEV₁ %predicted, FVC %predicted, FEV₁/FVC). The four highest quintiles (Q2-Q5) were compared to the lowest (Q1) to assess their relationship with all-cause mortality, cardiovascular events, and moderate-to-severe and severe exacerbations. Cox-regression was used, adjusted for age, sex, ethnicity, body-mass index, smoking status, previous exacerbations, cardiovascular disease, treatment, and modified Medical Research Council dyspnea score.

Results

Compared to Q1 (<53.5% FEV₁ predicted), increasing FEV₁ quintiles (Q2 53.5-457.5% predicted, Q3 57.5-461.6% predicted, Q4 61.6-465.8% predicted, and Q5 ≥65.8%) were all associated with significantly decreased all-cause mortality (20% (4-34%), 28% (13-40%), 23% (7-36%), and 30% (15-42%) risk reduction, respectively). In contrast, a significant risk reduction (21% (4-35%)) was seen only between Q1 and Q5 quintiles of FVC. Neither FEV₁ nor FVC was associated with cardiovascular risk. Increased FEV₁ and FEV₁/FVC quintiles were also associated with the reduction of moderate-to-severe and severe exacerbations while, surprisingly, the highest FVC quintile was related to the heightened exacerbation risk (28% (8-52%) risk increase).

Conclusion

Our results suggest that FEV₁ is a stronger predictor for all-cause mortality than FVC in moderate COPD patients with heightened cardiovascular risk and that subjects with moderate COPD have very different risks.