Systemic inflammation in COPD in relation to smoking status

Telomere Length but Not Mitochondrial DNA Copy Number Is Altered in Both Young and Old COPD

Accelerated ageing is implicated in the pathogenesis of respiratory diseases as chronic obstructive pulmonary disease (COPD), but recent evidence indicates that the COPD can have roots early in life. Here we hypothesise that the accelerated ageing markers might have a role in the pathobiology of young COPD. The objective of this study was to compare two hallmarks of ageing, telomere length (TL), and mitochondrial DNA copy number (mtDNA-CN, as a surrogate marker of mitochondrial dysfunction) in young (≤ 50 years) and old (>50 years) smokers, with and without COPD. Both, TL and mtDNA-CN were measured in whole blood DNA by quantitative PCR [qPCR] in: (1) young ever smokers with (n = 81) or without (n = 166) COPD; and (2) old ever smokers with (n = 159) or without (n = 29) COPD. A multivariable linear regression was used to assess the association of TL and mtDNA-CN with lung function. We observed that in the entire study population, TL and mtDNA-CN decreased with age, and the former but not the latter related to FEV₁/FVC (%), FEV₁ (% ref.), and DLCO (% ref.). The short telomeres were found both in the young and old patients with severe COPD (FEV₁ <50% ref.). In addition, we found that TL and mtDNA-CN were significantly correlated, but their relationship was positive in younger while negative in the older patients with COPD, suggesting a mitochondrial dysfunction. We conclude that TL, but not mtDNA-CN, is associated with the lung function impairment. Both young and old patients with severe COPD have evidence of accelerated ageing (shorter TL) but differ in the direction of the correlation between TL and mtDNA-CN in relation to age.

Effect of urban air pollution on CRP and coagulation: a study on inpatients with acute exacerbation of chronic obstructive pulmonary disease

PURPOSE

Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is an important event in the course of chronic obstructive pulmonary disease that negatively affects patients' quality of life and leads to higher socioeconomic costs. While previous studies have demonstrated a significant association between urban air pollution and hospitalization for AECOPD, there is a lack of research on the impact of particulate matter (PM) on inflammation and coagulation in AECOPD inpatients. Therefore, this study investigated the association of changes in coagulation function and C-reactive protein (CRP) with PM levels in the days preceding hospitalization.

PATIENTS AND METHODS

We reviewed the medical records of AECOPD patients admitted to Putuo Hospital, Shanghai University of Traditional Chinese Medicine, between March 2017 and September 2019. We analyzed the association of coagulation function and CRP level in AECOPD patients with PM levels in the days before hospitalization. Multivariate unconditional logistic regression analyses were used to evaluate the adjusted odds ratio (OR) and 95% confidence interval (CI) for the association of CRP data with hospitalization day. Kruskal-Wallis tests were used to evaluate mean aerodynamic diameter of ≥ 2.5 μm (PM_2.5) exposure on the day before hospitalization; we assessed its association with changes in prothrombin time (PT) in AECOPD inpatients with different Global Initiative for Chronic Obstructive Lung Disease (GOLD) classes.

RESULTS

The peripheral blood PT of AECOPD patients with PM_2.5 ≥ 25 mg/L on the day before hospitalization were lower than those of patients with PM_2.5 < 25 mg/L (t = 2.052, p = 0.041). Patients with severe GOLD class exposed to greater than 25 mg/L of PM_2.5on the day before hospitalization showed significant differences in PT (F = 9.683, p = 0.008). Peripheral blood CRP levels of AECOPD patients exposed to PM_2.5 ≥ 25 mg/L and PM₁₀ ≥ 50 mg/L on the day before hospitalization were higher than those of patients exposed to PM_2.5 < 25 mg/L and PM₁₀ < 50 mg/L (t = 2.008, p = 0.046; t = 2.637, p = 0.009). Exposure to < 25 mg/L of PM_2.5 on the day before hospitalization was significantly associated with CRP levels (adjusted OR 1.91; 95% CI 1.101, 3.315; p = 0.024).

CONCLUSION

Exposure of patients with AECOPD to high PM levels on the day before hospitalization was associated with an increased CRP level and shortened PT. Moreover, PM_2.5 had a greater effect on CRP level and PT than mean aerodynamic diameter of ≥ 10 μm (PM₁₀). AECOPD patients with severe GOLD class were more sensitive to PM_2.5-induced shortening of PT than those with other GOLD classes.

IL-33 blockade affects mediators of persistence and exacerbation in a model of chronic airway inflammation

BACKGROUND

Severe inflammatory airway diseases are associated with inflammation that does not resolve, leading to structural changes and an overall environment primed for exacerbations.

OBJECTIVE

We sought to identify and inhibit pathways that perpetuate this heightened inflammatory state because this could lead to therapies that allow for a more quiescent lung that is less predisposed to symptoms and exacerbations.

METHODS

Using prolonged exposure to house dust mite in mice, we developed a mouse model of persistent and exacerbating airway disease characterized by a mixed inflammatory phenotype.

RESULTS

We show that lung IL-33 drives inflammation and remodeling beyond the type 2 response classically associated with IL-33 signaling. IL-33 blockade with an IL-33 neutralizing antibody normalized established inflammation and improved remodeling of both the lung epithelium and lung parenchyma. Specifically, IL-33 blockade normalized persisting and exacerbating inflammatory end points, including eosinophilic, neutrophilic, and ST2⁺CD4⁺ T-cell infiltration. Importantly, we identified a key role for IL-33 in driving lung remodeling because anti-IL-33 also re-established the presence of ciliated cells over mucus-producing cells and decreased myofibroblast numbers, even in the context of continuous allergen exposure, resulting in improved lung function.

CONCLUSION

Overall, this study shows that increased IL-33 levels drive a self-perpetuating amplification loop that maintains the lung in a state of lasting inflammation and remodeled tissue primed for exacerbations. Thus IL-33 blockade might ameliorate symptoms and prevent exacerbations by quelling persistent inflammation and airway remodeling.

Oxidized Alpha-1-Antitrypsin as a Potential Biomarker Associated with Onset and Severity of Chronic Obstructive Pulmonary Disease in Adult Population

Oxidative stress could reduce inhibitor activity of the alpha-1-antitrypsin (A1AT). Oxidative-modified A1AT (oxidized alpha-1-antitrypsin, OxyA1AT) significantly loses ability to protect the lungs from neutrophil elastase. We aimed to investigate OxyA1AT as a potential biomarker associated with onset and severity of chronic obstructive pulmonary disease (COPD) in adult population. The study included 65 patients with COPD (33 smokers and 32 no-smokers) and 46 healthy participants (17 smokers and 29 no-smokers). Determination of OxyA1AT in serum was based on the difference between the inhibitory activities of normal and oxidized A1AT against trypsin and elastase. The level of OxyA1AT was significantly increased in the group of COPD smokers compared to healthy no-smokers (p = 0.030) and COPD no-smokers (p = 0.009). The highest level of OxyA1AT was found in group of smokers with severe and very severe COPD in comparison to the following: no-smokers with the same stage of disease (p = 0.038), smokers with moderate COPD (p = 0.022), and the healthy control group, regardless of the smoking status (control no-smokers p = 0.001 and control smokers p = 0.034). In conclusion, serum level of OxyA1AT would be potentially good biomarker for the assessment of harmful effect of smoking to the onset and severity of COPD. Also, clinical significance of OxyA1AT as prognostic biomarker could be useful in assessing the effectiveness of antioxidant therapy for COPD and emphysema. Suitable and inexpensive laboratory method for determination of OxyA1AT is additional benefit for the introduction of OxyA1AT into routine clinical practice for diagnosis and monitoring of COPD.

Systemic Immuno-metabolic alterations in chronic obstructive pulmonary disease (COPD)

BACKGROUND

Metabolic adaptation in immune cells is necessary to modulate immune cell function as it is intricately coupled with intracellular metabolism. We aimed to characterize the metabolic state of human peripheral blood mononuclear cells (PBMCs) after long-term exposure to tobacco smoke in smokers with preserved lung function and COPD subjects.

METHODS

PBMCs were isolated from healthy non-smokers (HNS), healthy smokers (HS) and COPD subjects, cultured and the mitochondrial respiration while utilizing glucose (glycolysis), fatty acids (β-oxidation) or pyruvate (direct Krebs' cycle substrate) was measured using the XFp Extracellular Flux Analyzer. Plasma levels of inflammatory cytokines IFN-γ, IL-17, TNF-α, IL-5, IL-9 and IFN-α were measured using flow cytometry. RAW264.7 cells were exposed to cigarette smoke condensate (CSC) for 1 h and its effect on cell viability, cellular metabolism and phagocytosis ability were also studied. Patient's data was analyzed using the Mann Whitney U test, whereas Student's t test was performed to analyze the in-vitro data.

RESULTS

PBMCs from COPD subjects showed a significant decrease in extracellular acidification rate (ECAR) while utilizing glucose as compared to HNS (151.9 Vs 215%). Mitochondrial oxygen consumption rate (OCR) on palmitate or pyruvate was also found to be significantly lower in COPD subjects as compared to HS and a strong positive correlation between palmitate OCR in PBMCs and FEV1 (r = 0.74, p < 0.05) and FVC (r = 0.79, p < 0.05) values in HS was observed. The metabolic shift towards fatty acid metabolism in healthy smokers promoted an inflammatory cytokine response with a greater increase in the levels of IL-5, IL-9 and IFN-α as compared to IFN-γ, IL-17 and TNF-α. In-vitro experiments with RAW 264.7 cells showed similar metabolic alterations and a reduced ability to phagocytose Streptococcus pneumonia and Haemophilus influenza after cigarette smoke exposure in the presence of glucose or palmitate.

CONCLUSIONS

These findings indicate a metabolic basis for the inflammatory response in COPD and could suggest a new therapeutic target for controlling the immune response and delaying the onset of disease.

TRIAL REGISTRATION

This observational study was retrospectively registered in the Clinical Trails Registry - India (ICMR - NIMS) on 19th January 2018 with the registration number CTRI/2018/01/011441 .

The prevalence of PI*S and PI*Z SERPINA1 alleles in healthy individuals and COPD patients in Saudi Arabia: A case-control study

Alpha-1 antitrypsin (AAT) is an acute phase protein produced in hepatocytes. Its deficiency affects the lungs and liver. A case-control study was carried out to determine the prevalence of 2 common deficiency alleles, PI*S and PI*Z, for alpha-1 antitrypsin deficiency (AATD) in both healthy and chronic obstructive pulmmonary disease (COPD)-affected Saudi populations and to clarify the importance of genetic tests in the screening of people at risk for COPD.One thousand blood samples from healthy individuals and 1000 from COPD-affected Saudi individuals were genotyped for the above-mentioned alleles, using real-time polymerase chain reaction (PCR), with the exclusion of any other nationalities. Data were analyzed by determining the allele and genotype frequencies through gene counting and its confidence intervals. The allele frequencies, derived by the Hardy-Weinberg equilibrium method, were analyzed by Pearson Chi-squared tests. The confidence intervals for genotype frequencies were calculated using exploratory software for confidence intervals.Of the 1000 COPD patients included in our study, the prevalence of PI*S and PI*Z was 21.8% and 7.7%, respectively, while within the 1000 normal samples, these alleles occurred in 8.9% of patients for PI*S and 1.6% for PI*Z. The AAT deficiency genotype frequencies (PI*ZZ, PI*SS, and PI*SZ) were 6.5 per 1000 and 87 per 1000 for normal and COPD-affected Saudi individuals.Our results indicated a high prevalence of AATD alleles in the normal Saudi population and an association between AAT deficiency and pulmonary disease development. Additionally, our research confirms the importance of genetic screening to achieve early and accurate diagnosis of AATD.

[Systemic inflammatory profile of smokers with and without COPD]

INTRODUCTION

Studies comparing the systemic inflammatory profiles of smokers with and without COPD present discordant findings.

AIM

To compare the systemic inflammatory profile of smokers with and without COPD.

METHODS

This is a cross-sectional comparative study. Two groups of active smokers of more than 10 pack-years were included: 56 consecutives stable COPD (postbronchodilator FEV₁/FVC<0.70) and 32 consecutives non-COPD (postbronchodilator FEV₁/FVC≥0.70). Smoking and clinical, anthropometric and spirometric data were noted. The following blood biomarkers were identified: leukocytes, hemoglobin, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR). According to the levels (normal/abnormal) of these markers, two groups of smokers were formed. Quantitative and qualitative data were expressed, respectively, as means±SD and percentages.

RESULTS

Compared to the non-COPD group, the COPD group was older (56±12 vs. 65±8 years) and had a higher smoking consumption (30±18 vs. 52±31 pack-years). Compared to the non-COPD group, the COPD group had higher values of CRP (2.06±1.24 vs. 11.32±11.03mg/L), of ESR (9.59±8.29 vs. 15.96±11.56), of IL-6 (9.28±4.69 vs. 20.27±5.31ng/L) and of TNF-α (18.38±7.98ng/L vs. 8.62±3.72ng/L). Compared to the non-COPD group, the COPD group included higher percentages of smokers with elevated CRP (0 % vs. 32 %), with leukocytosis (6 % vs. 16 %), with higher levels of IL-6 (81 % vs. 98 %) or TNF-α (91 % vs. 100 %).

CONCLUSION

Smokers with COPD, compared to smokers free from COPD, have a marked systemic inflammation.

Tumor necrosis factor receptor 2 as a possible marker of COPD in smokers and ex-smokers

Introduction

Oxidative stress and systemic inflammation are higher in smokers and patients with COPD; however, markers that may help differentiate between smokers and patients with COPD have not yet been identified. We hypothesized that tumor necrosis factor-alpha receptor (TNFR) and soluble form of the receptor for advanced glycation end products (sRAGE) can be indicators of COPD in asymptomatic patients.

Patients and methods

We evaluated 32 smokers (smoking history >10 pack-years), 32 patients with mild/moderate COPD (smokers and ex-smokers), and 32 never smokers. Concentrations of C-reactive protein (CRP), interleukin (IL)-6, TNFR1 and TNFR2, advanced glycation end products (AGEs), and the sRAGE were measured in serum.

Results

There were higher CRP and AGEs concentrations in smokers and in patients with COPD (P<0.001 and P=0.01, respectively) compared to controls, without statistical difference between smokers and patients with COPD. Concentrations of sRAGE, IL-6, and TNFR1 did not differ between study groups. TNFR2 was significantly higher in patients with COPD than in smokers (P=0.004) and controls (P=0.004), and the presence of COPD (P=0.02) and CRP (P=0.001) showed a positive association with TNFR2. Positive associations for smoking (P=0.04), CRP (P=0.03), and IL-6 (P=0.03) with AGEs were also found. The interaction variable (smoking × COPD) showed a positive association with IL-6.

Conclusion

Our data suggest that TNFR2 may be a possible marker of COPD in asymptomatic smokers and ex-smokers. Although smokers and patients with early COPD presented other increased systemic inflammation markers (eg, CRP) and oxidative stress (measured by AGEs), they did not differentiate smokers from COPD.

Plasma α1-antitrypsin: a neglected predictor of angiographic severity in patients with stable angina pectoris

Background:

As an acute phase protein, α1-antitrypsin (AAT) has been extensively studied in acute coronary syndrome, but it is unclear whether a relationship exists between AAT and stable angina pectoris (SAP). The purpose of the present study was to investigate the association between AAT plasma levels and SAP.

Methods:

Overall, 103 SAP patients diagnosed by coronary angiography and clinical manifestations and 118 control subjects matched for age and gender were enrolled in this case-control study. Plasma levels of AAT, high-sensitivity C-reactive protein (hsCRP), lipid profiles and other clinical parameters were assayed for all participants. The severity of coronary lesions was evaluated based on the Gensini score (GS) assessed by coronary angiography.

Results:

Positively correlated with the GS (r = 0.564, P < 0.001), the plasma AAT level in the SAP group was significantly higher than that in the control group (142.08 ± 19.61 mg/dl vs. 125.50 ± 19.67 mg/dl, P < 0.001). The plasma AAT level was an independent predictor for both SAP (odds ratio [OR] = 1.037, 95% confidence interval [CI]: 1.020–1.054, P < 0.001) and a high GS (OR = 1.087, 95% CI: 1.051–1.124, P < 0.001) in a multivariate logistic regression model. In the receiver operating characteristic curve analysis, plasma AAT level was found to have a larger area under the curve (AUC) for predicting a high GS (AUC = 0.858, 95% CI: 0.788–0.929, P < 0.001) than that of hsCRP (AUC = 0.665, 95% CI: 0.557–0.773, P = 0.006; Z = 2.9363, P < 0.001), with an optimal cut-off value of 137.85 mg/dl (sensitivity: 94.3%, specificity: 68.2%).

Conclusions:

Plasma AAT levels correlate with both the presence and severity of coronary stenosis in patients with SAP, suggesting that it could be a potential predictive marker of severe stenosis in SAP patients.

[Clinical and laboratory parameters in assessing the risk of exacerbations in chronic obstructive pulmonary disease]

AIM

To estimate the significance of measuring the concentrations of cytokines and immunoglobulins and the relative counts of lymphocyte subpopulations in peripheral blood, as well as clinical parameters in patients with chronic obstructive pulmonary disease (COPD) in order to assess the risk of exacerbations.

SUBJECTS AND METHODS

Thirty-seven patients with COPD were examined. A study group consisted of 31 patients. Patients with rare exacerbations were assigned to those who had no or one case; patients with frequent exacerbations were those who had two or more cases a year after examination. A prognostic model was created using the binary logistic regression analysis.

RESULTS

A significant statistical model was developed as a regression equation involving 4 indicators (vascular endothelial growth factor, C-reactive protein, CAT scores, and number of exacerbations in the previous year). This mathematical model can predict frequent exacerbations in next year with a sensitivity of 94.1% and a specificity of 80%.

CONCLUSION

The mathematical model created to estimate the risk of frequent exacerbations may be used to elaborate adequate individual treatment regimens for both smoking and non-smoking patients with COPD.

Activity of α1-antitrypsin and some lysosomal enzymes in the blood serum of patients with chronic obstructive pulmonary disease after smoking cessation

The activity of α₁-antitrypsin (AAT) and the lysosomal enzymes, cathepsin D (CTS D), arylsulfatase (ASA), and acid phosphatase, (AcP) was determined in patients with COPD (GOLD category A). Moreover, the diagnostic usefulness of these parameters in blood serum was assessed along with establishing whether smoking cessation affects these parameters. The study included 70 patients with COPD who ceased smoking (study group) and two control groups of 33 subjects each: nonsmokers without COPD (control I) and patients with COPD who continued smoking (control II). In control I, blood was taken once and in control II, at the start of the experiment and after the 1st, 2nd, and 3rd months. AAT in the patients exhibited higher activity than in the healthy subjects at all time points. AAT activity in the patients before the start of the experiment was ~80% higher (P < 0.001) than in control I. No statistically significant differences in CTS D, ASA, and AcP activity were found. COPD involves increased AAT activity and unchanged activities of the assessed lysosomal enzymes. Three-month tobacco abstinence does not affect these parameters in peripheral blood. Determining the AAT levels in blood serum can be used in the diagnostics of COPD.

The circulating proteinase inhibitor α-1 antitrypsin regulates neutrophil degranulation and autoimmunity

Pathological inflammation and autoimmune disease frequently involve elevated neutrophil activity in the absence of infectious agents. Tumor necrosis factor-α (TNF-α) contributes to many of the problems associated with autoimmune diseases. We investigated the ability of serum α-1 antitrypsin (AAT) to control TNF-α biosynthesis and signaling in neutrophils and assessed whether AAT deficiency (AATD) is a TNF-α-related disease. In vitro studies demonstrate that serum AAT coordinates TNF-α intracellular signaling and neutrophil degranulation of tertiary and secondary granules via modulation of ligand-receptor interactions. AATD patients homozygous for the Z allele were characterized by increased activation of the TNF-α system, as demonstrated by increased membrane TNF-α levels and increased plasma concentrations of TNF receptor 1 and neutrophil-released secondary and tertiary granule proteins. The incidence of autoantibodies directed against degranulated lactoferrin and surface protein accessible to these antibodies was increased in ZZ-AATD, leading to an enhanced rate of neutrophil reactive oxygen species production. Treatment of ZZ-AATD individuals with AAT augmentation therapy resulted in decreased membrane TNF-α expression and plasma levels of granule antigenic proteins and immunoglobulin G class autoantibodies. These results provide a mechanism by which AAT augmentation therapy affects TNF-α signaling in the circulating neutrophil, indicating promising potential of this therapy for other TNF-α-related diseases.

The relationship between C-reactive protein and prognostic factors in chronic obstructive pulmonary disease

BACKGROUND

The purpose of the study was to determine the relationship between high sensitivity C-reactive protein (hs-CRP) levels and prognostic factors in chronic obstructive pulmonary disease.

METHODS

We studied 50 stable COPD patients with: spirometry, 6 minute walk distance, body mass index, GOLD stage (spirometric classification) and smoking status. In these patients hs-CRP values were measured and compared with those of 50 healthy controls. Then the serum hs-CRP was subjected to evaluation for any correlation with the predictors of outcomes in COPD subjects.

RESULTS

Hs-CRP levels were higher in COPD patients than in controls (4.82 vs. 0.88 mg/L p < 0.01). Correlation was found between hs-CRP and the following variables: FEV1 (r= -0.813; p < 0.01), 6MWD (r= -0.876; p < 0.01), body mass index (r= -0.710; p < 0.01), GOLD stage (r= 0.797, p < 0.01) and smoking status (r= 0.796; p < 0.01). Using multivariate analysis, FEV1 and 6MWD showed the strongest negative association with hs-CRP levels.

CONCLUSIONS

The circulating levels of the inflammatory marker hs-CRP are significantly elevated in patients with COPD, supporting the view that COPD is in part an inflammatory disorder. Hs-CRP levels in stable COPD patients are best correlated with FEV1 and 6-minute walk distance (6MWD). This information should be considered when hs-CRP levels are measured in stable COPD patients.

Airway bacterial colonization: the missing link between COPD and cardiovascular events?

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death worldwide and, according to the World Health Organization, its prevalence will double by 2020. COPD is a chronic inflammatory disease of the lung characterized by poorly reversible airflow limitation and, frequently, by extrapulmonary manifestations. In particular, the cardiovascular manifestations are responsible for high morbidity and mortality.

METHODS AND RESULTS

A systematic literature search was performed of studies published in Medline until December 2010, using the key-words: COPD, bacterial colonization, COPD exacerbation, atherosclerosis, systemic inflammation, cardiovascular event and risk factors. In addition to the studies identified in the primary search, reference lists of included articles were analyzed for additional papers related to the topic. The pathogenetic mechanisms underlying atherosclerosis - namely inflammation, oxidative stress and endothelial dysfunction - are in common with COPD. Moreover, they are increased in the presence of COPD, especially in patients who present airway bacterial colonization, increased rate of exacerbations and elevated levels of both airway and systemic inflammation.

CONCLUSION

COPD is associated with an increased burden of atherosclerotic disease. Systemic inflammation and oxidative stress play key roles in this association. COPD patients with airway bacterial colonization, as compared to patients without airway colonization, generally present more frequent exacerbations and higher levels of both airway and systemic inflammation. This COPD subgroup should be considered at particularly increased risk of developing cardiovascular complications and receive more attention concerning diagnosis, treatment, prevention and research.