Neutrophil-to-lymphocyte ratio in chronic obstructive pulmonary disease: a retrospective study

Relationship between neutrophil lymphocyte ratio and red blood cell distribution width and respiratory failure in COPD patients

The neutrophil lymphocyte ratio (NLR) and red blood cell distribution width (RDW) have been repeatedly demonstrated to be associated with risk of severity, progression, and prognosis of chronic obstructive pulmonary disease (COPD), but data on respiratory failure (RF) in patients with COPD are very limited. This study aimed to examine the relationship between NLR and RDW and the incident RF in patients with COPD. This is a retrospective study that reviewed data by examining the hospitalization medical records to identify those who were admitted with a diagnosis of COPD. Based on whether RF occurred during index hospitalization, patients were classified as COPD group and COPD combined with RF group. Also, healthy controls of the same age and sex were enrolled in a 1:1 ratio as the COPD group. Univariate comparisons were performed between three groups to examine differences. With the COPD group as reference, multivariable logistic regression was formed to identify the relationship between NLR and RDW and RF, with adjustment for multiple covariates. There were 136 healthy controls, 136 COPD patients and 62 patients with COPD combined with RF included for analysis. There was a significant difference for eight variables, including age, WBC, neutrophil, NLR, RDW, platelet, PLR, and CRP. The Spearman test showed the significant correlation between NLR and WBC (correlation coefficient, 0.38; P = .008), NLR and RDW (correlation coefficient, 0.32; P = .013), and NLR and CRP level (correlation coefficient, 0.54; P < .001). The multivariable logistic regression showed that age (every additional 10 years) (OR, 1.785), NLR (OR, 1.716), RDW (OR, 2.266), and CRP (OR, 1.163) were independently associated with an increased risk of RF. This study demonstrated the independent associative effect of NLR and RDW with RF in patients with COPD, exhibiting the potential clinical role in evaluating the progress of COPD to RF.

The role of neutrophil to lymphocyte ratio in patients with COPD-OSA overlap syndrome

PURPOSE

The aim of this study is to investigate the role of the neutrophil to lymphocyte ratio (NLR) in patients diagnosed with the chronic obstructive pulmonary disease-obstructive sleep apnea (COPD-OSA) overlap syndrome and comorbid pulmonary hypertension (PH).

PATIENTS AND METHODS

We enrolled a consecutive of stable COPD patients and conducted spirometry measurements, nocturnal polysomnography (PSG), and echocardiography for all participants. Clinical laboratory data were collected.

RESULTS

A total of 178 patients with stable COPD were enrolled among whom 33.14% (59/178) were diagnosed with OSA. Of the patients with overlap syndrome, 35.59% (21/59) showed comorbid PH, compared to 34.45% (41/119) in COPD patients without OSA. There was no significant difference in the occurrence of PH between COPD with and without OSA. NLR was significantly higher in patients with overlap syndrome compared to those with either disease alone. The difference in NLR between COPD-OSA patients with and without PH was not significant. Correlation analysis revealed that NLR was associated with age, total sleep time spent with oxygen saturation below 90% (T90), CRP, pulmonary artery systolic pressure (PASP), and minimum peripheral capillary oxygen saturation (SpO2min) in all COPD patients. NLR was identified as an independent factor contributing to OSA in COPD. The median cut-off value for detecting OSA in stable COPD was 2.49. However, NLR was not found to be a predictor for PH in COPD-OSA overlap syndrome.

CONCLUSIONS

NLR can serve as a predictive marker for comorbid OSA in patients with COPD. NLR is expected to increase its clinical application as a convenient and cost-effective biomarker for COPD-OSA overlap syndrome.

A Murine Model of Vesicant-Induced Acute Lung Injury

Burn injuries including those caused by chemicals can result in systemic effects and acute lung injury (ALI). Cutaneous exposure to Lewisite, a warfare and chemical burn agent, also causes ALI. To overcome the limitations in conducting direct research on Lewisite-induced ALI in a laboratory setting, an animal model was developed using phenylarsine oxide (PAO) as a surrogate for Lewisite. Due to lack of a reliable animal model mimicking the effects of such exposures, development of effective therapies to treat such injuries is challenging. We demonstrated that a single cutaneous exposure to PAO resulted in disruption of the alveolar-capillary barrier as evidenced by elevated protein levels in the bronchoalveolar lavage fluid (BALF). BALF supernatant of PAO-exposed animals had increased levels of high mobility group box 1, a damage associated molecular pattern molecule. Arterial blood-gas measurements showed decreased pH, increased PaCO2, and decreased partial pressure of arterial O2, indicative of respiratory acidosis, hypercapnia, and hypoxemia. Increased protein levels of interleukin (IL)-6, CXCL-1, CXCL-2, CXCL-5, granulocyte-macrophage colony-stimulating factor, CXCL-10, leukemia inhibitory factor, leptin, IL-18, CCL-2, CCL-3, and CCL-7 were observed in the lung of PAO-exposed mice. Further, vascular endothelial growth factor levels were reduced in the lung. Pulmonary function evaluated using a flexiVent showed a downward shift in the pressure-volume loop, decreases in static compliance and inspiratory capacity, increases in respiratory elastance and tissue elastance. These changes are consistent with an ALI phenotype. These results demonstrate that cutaneous PAO exposure leads to ALI and that the model can be used as an effective surrogate to investigate vesicant-induced ALI. SIGNIFICANCE STATEMENT: This study presents a robust model for studying ALI resulting from cutaneous exposure to PAO, a surrogate for the toxic vesicating agent Lewisite. The findings in this study mimic the effects of cutaneous Lewisite exposure, providing a reliable model for investigating mechanisms underlying toxicity. The model can also be used to develop medical countermeasures to mitigate ALI associated with cutaneous Lewisite exposure.

Predictive role of neutrophil-percentage-to-albumin, neutrophil-to-lymphocyte and eosinophil-to-lymphocyte ratios for mortality in patients with COPD: Evidence from NHANES 2011-2018

BACKGROUND AND OBJECTIVE

This study evaluated the predictive roles of hematologic inflammatory biomarkers including neutrophil-percentage-to-albumin ratio (NPAR), neutrophil-to-lymphocyte ratio (NLR) and eosinophil-to-lymphocyte ratio (ELR) for mortality in community-dwelling individuals with chronic obstructive pulmonary disease (COPD).

METHODS

This longitudinal study extracted data of adults 40-79 years who had physician-diagnosed COPD from the United States (US) National Health and Nutrition Examination Survey (NHANES) 1999-2018. Cox regressions determined the associations between NPAR, NLR, ELR and their components, with all-cause mortality, cardiovascular disease (CVD) mortality and mortality from chronic lower respiratory disease (CLRD). Receiver operating characteristic (ROC) curve analysis estimated the predictive performances of these biomarkers for 5-year all-cause mortality.

RESULTS

Data of 1158 subjects were analysed. After adjustment, higher NPAR was significantly associated with increased all-cause and CVD mortality, and mortality from CLRD (adjusted hazard ratio [aHR] = 1.14, 1.15 and 1.16). Higher NLR was associated with an increased all-cause and CVD mortality (aHR = 1.16 and 1.29). Higher neutrophil was associated with increased all-cause mortality and mortality from CLRD (aHR = 1.13 and 1.34). Albumin was associated with decreased all-cause and CVD mortality (aHR = 0.91 and 0.86). ELR, eosinophil or lymphocyte was not significantly associated with either mortality outcomes. Adjusted AUC of NPAR and NLR in predicting 5-year all-cause mortality were 0.808 (95% CI: 0.722-0.845) and 0.799 (95% CI: 0.763-0.835), respectively.

CONCLUSION

In community-dwelling US adults with COPD, increased NPAR and NLR are associated with mortality risks. NPAR outperforms the other hematologic inflammatory biomarkers in predicting 5-year all-cause mortality.

NLR in CBC: A holy grail for biomarker research in COPD?

See related article

Association of Red Cell Index and Hospital Mortality in Chronic Obstructive Pulmonary Disease Patients Admitted to the Intensive Care Unit: A Retrospective Cohort Study

Purpose

This study aims to explore the association between red cell index (RCI) and hospital mortality in Chronic Obstructive Pulmonary Disease (COPD) patients in the intensive care unit.

Patients and Methods

This was a retrospective cohort research. The study included 821 COPD patients. Clinical data from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database was conducted. Multivariate logistic regression analysis was used to assess the correlation between RCI and in-hospital mortality. Age, SOFA score, diabetes mellitus, cerebrovascular disease, congestive heart failure and mechanical ventilation were considered for subgroup analysis.

Results

This study comprised 821 patients, of which 16.5% (124/821) suffered hospital mortality. In the multivariate logistic regression model, RCI was positively associated with hospital mortality, each unit increase in RCI was associated with a 3% increase in hospital mortality (odds ratio [OR] =1.03; 95% confidence interval [95CI%] =1.01-1.06). Meanwhile, compare with the lowest RCI group, the highest RCI groups tended to have higher risks of hospital mortality (OR [95% CI] 2.33 [1.27-4.27]). Additionally, subgroup analysis result was persistent among all the groups.

Conclusion

Higher RCI was positively associated with a higher risk of mortality in critically ill patients with COPD. Further investigation is necessary to confirm these findings.

Vitamin D status modulates innate immune responses and metabolomic profiles following acute prolonged cycling

PURPOSE

The influence of vitamin D status on exercise-induced immune dysfunction remains unclear. The aim of this study was to investigate the effects of vitamin D status (circulating 25(OH)D) on innate immune responses and metabolomic profiles to prolonged exercise.

METHODS

Twenty three healthy, recreationally active males (age 25 ± 7 years; maximal oxygen uptake [[Formula: see text]max] 56 ± 9 mL·kg-1·min-1), classified as being deficient (n = 7) or non-deficient n = 16) according to plasma concentrations of 25(OH)D, completed 2.5 h of cycling at 15% Δ (~ 55-60% [Formula: see text]max). Venous blood and unstimulated saliva samples were obtained before and after exercise.

RESULTS

Participants with deficient plasma 25(OH)D on average had lower total lymphocyte count (mean difference [95% confidence interval], 0.5 cells × 109 L [0.1, 0.9]), p = 0.013) and greater neutrophil:lymphocyte ratio (1.3 cells × 109 L, [0.1, 2.5], p = 0.033). The deficient group experienced reductions from pre-exercise to 1 h post-exercise (- 43% [- 70, - 15], p = 0.003) in bacterial stimulated elastase in blood neutrophils compared to non-deficient participants (1% [- 20, 21], p = 1.000) Multivariate analyses of plasma metabolomic profiles showed a clear separation of participants according to vitamin D status. Prominent sources of variation between groups were purine/pyrimidine catabolites, inflammatory markers (linoleic acid pathway), lactate and tyrosine/adrenaline.

CONCLUSION

These findings provide evidence of the influence of vitamin D status on exercise-induced changes in parameters of innate immune defence and metabolomic signatures such as markers of inflammation and metabolic stress.

Diagnostic efficacy of systemic immune-inflammation biomarkers in benign prostatic hyperplasia using receiver operating characteristic and artificial neural network

Benign prostatic hyperplasia (BPH) is a chronic, progressive disease characterized by mesenchymal cell-predominance and stromal and glandular cell-hyperproliferation. Although, the precise cause of BPH is unknown, it is believed to be associated with hormonal changes in aging men. Despite androgens and ageing are likely to play a role in the development of BPH, the pathophysiology of BPH remains uncertain. This paper aims to evaluate the diagnostic efficacy of platelet-to-lymphocyte ratio (PLR), neutrophil-lymphocyte ratio (NLR) and systemic immune-inflammation index in in diagnosing BPH. A single-center-randomized-retrospective study was carried out at Alzahraa university hospital between January 2022 and November 2022 on 80 participants (40 non-BPH subjects and 40 patients with symptomatic enlarged prostate) who visited the outpatient clinic or admitted to the urology department. The BPH cases were evaluated by digital rectal examination (DRE), International Prostate Symptom Score (IPSS), prostate size, prostate specific antigen (PSA), TRUS biopsy in elevated PSA > 4 ng/ml, PLR, NLR and systemic immune inflammatory (SII). The diagnosing efficiency of the selected parameters was evaluated using Receiver Operating Characteristic (ROC) and Artificial Neural Network (ANN) showing excellent discrimination with 100% accuracy and AUC = 1 in the ROC curves. Moreover, the accuracy rate of the ANN exceeds 99%. Conclusion: PLR, NLR and SII can be significantly employed for diagnosing BPH.

A meta-analysis of immune-cell fractions at high resolution reveals novel associations with common phenotypes and health outcomes

BACKGROUND

Changes in cell-type composition of tissues are associated with a wide range of diseases and environmental risk factors and may be causally implicated in disease development and progression. However, these shifts in cell-type fractions are often of a low magnitude, or involve similar cell subtypes, making their reliable identification challenging. DNA methylation profiling in a tissue like blood is a promising approach to discover shifts in cell-type abundance, yet studies have only been performed at a relatively low cellular resolution and in isolation, limiting their power to detect shifts in tissue composition.

METHODS

Here we derive a DNA methylation reference matrix for 12 immune-cell types in human blood and extensively validate it with flow-cytometric count data and in whole-genome bisulfite sequencing data of sorted cells. Using this reference matrix, we perform a directional Stouffer and fixed effects meta-analysis comprising 23,053 blood samples from 22 different cohorts, to comprehensively map associations between the 12 immune-cell fractions and common phenotypes. In a separate cohort of 4386 blood samples, we assess associations between immune-cell fractions and health outcomes.

RESULTS

Our meta-analysis reveals many associations of cell-type fractions with age, sex, smoking and obesity, many of which we validate with single-cell RNA sequencing. We discover that naïve and regulatory T-cell subsets are higher in women compared to men, while the reverse is true for monocyte, natural killer, basophil, and eosinophil fractions. Decreased natural killer counts associated with smoking, obesity, and stress levels, while an increased count correlates with exercise and sleep. Analysis of health outcomes revealed that increased naïve CD4 + T-cell and N-cell fractions associated with a reduced risk of all-cause mortality independently of all major epidemiological risk factors and baseline co-morbidity. A machine learning predictor built only with immune-cell fractions achieved a C-index value for all-cause mortality of 0.69 (95%CI 0.67-0.72), which increased to 0.83 (0.80-0.86) upon inclusion of epidemiological risk factors and baseline co-morbidity.

CONCLUSIONS

This work contributes an extensively validated high-resolution DNAm reference matrix for blood, which is made freely available, and uses it to generate a comprehensive map of associations between immune-cell fractions and common phenotypes, including health outcomes.

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.

Clinical significance of serum levels of 14-3-3β protein in patients with stable chronic obstructive pulmonary disease

Nowadays, the diagnosis and treatment of COPD are often based on the results of lung function tests. Certain individuals, however, are not candidates for lung function testing due to pulmonary bullae, cardiac failure, low lung function, and other factors. Therefore, we evaluated whether serum tyrosine3-monooxygenase/tryptophan5-monooxygenase activation protein β (14-3-3β) could be a biomarker for the diagnosis of stable COPD patients. The expression of serum 14-3-3β protein was evaluated by an enzyme-linked immunosorbent assay. The association between its concentrations and clinical parameters of stable COPD patients were analyzed by correlation analysis and ROC curve. The results before propensity score matching (PSM) showed that serum 14-3-3β protein concentrations (ng/ml) in stable COPD patients were significantly higher than in healthy controls (P < 0.001). Furthermore, serum 14-3-3β protein concentrations were higher in GOLD 3&4 COPD patients compared with healthy participants, GOLD 1 and GOLD 2 COPD patients (P < 0.05), which shows that the concentration of 14-3-3β protein correlates with disease severity in stable COPD patients. After 1:1 PSM, there was also a statistically significant rise in 14-3-3 protein levels in stable COPD patients compared to healthy controls (P < 0.01). Serum 14-3-3β protein levels were positively correlated with blood neutrophil levels (P < 0.05), and negatively related to lung function parameters in stable COPD patients (P < 0.01). When the cutoff value was set at 29.53 ng/ml, the ROC curve yielded a sensitivity of 84.9% and a specificity of 68.3% for diagnosing stable COPD. The 14-3-3β protein may be a potential serum biomarker for the diagnosis of stable COPD patients, which is associated with disease severity, systemic inflammation, and small airway obstruction.

cAMP-PDE signaling in COPD: Review of cellular, molecular and clinical features

Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death among non-contagious diseases in the world. PDE inhibitors are among current medicines prescribed for COPD treatment of which, PDE-4 family is the predominant PDE isoform involved in hydrolyzing cyclic adenosine monophosphate (cAMP) that regulates the inflammatory responses in neutrophils, lymphocytes, macrophages and epithelial cells The aim of this study is to investigate the cellular and molecular mechanisms of cAMP-PDE signaling, as an important pathway in the treatment management of patients with COPD. In this review, a comprehensive literature review was performed about the effect of PDEs in COPD. Generally, PDEs are overexpressed in COPD patients, resulting in cAMP inactivation and decreased cAMP hydrolysis from AMP. At normal amounts, cAMP is one of the essential agents in regulating metabolism and suppressing inflammatory responses. Low amount of cAMP lead to activation of downstream inflammatory signaling pathways. PDE4 and PDE7 mRNA transcript levels were not altered in polymorphonuclear leukocytes and CD8 lymphocytes originating from the peripheral venous blood of stable COPD subjects compared to healthy controls. Therefore, cAMP-PDE signaling pathway is one of the most important signaling pathways involved in COPD. By examining the effects of different drugs in this signaling pathway critical steps can be taken in the treatment of this disease.

Biological and Genetic Mechanisms of COPD, Its Diagnosis, Treatment, and Relationship with Lung Cancer

Chronic obstructive pulmonary disease (COPD) is one of the most prevalent chronic adult diseases, with significant worldwide morbidity and mortality. Although long-term tobacco smoking is a critical risk factor for this global health problem, its molecular mechanisms remain unclear. Several phenomena are thought to be involved in the evolution of emphysema, including airway inflammation, proteinase/anti-proteinase imbalance, oxidative stress, and genetic/epigenetic modifications. Furthermore, COPD is one main risk for lung cancer (LC), the deadliest form of human tumor; formation and chronic inflammation accompanying COPD can be a potential driver of malignancy maturation (0.8-1.7% of COPD cases develop cancer/per year). Recently, the development of more research based on COPD and lung cancer molecular analysis has provided new light for understanding their pathogenesis, improving the diagnosis and treatments, and elucidating many connections between these diseases. Our review emphasizes the biological factors involved in COPD and lung cancer, the advances in their molecular mechanisms' research, and the state of the art of diagnosis and treatments. This work combines many biological and genetic elements into a single whole and strongly links COPD with lung tumor features.

Predictive value of neutrophil-to-lymphocyte ratio and bilirubin levels in the readmission of acute exacerbation of chronic obstructive pulmonary disease

BACKGROUND

Th aim of this study was to analyze acute exacerbation of chronic obstructive pulmonary disease (AECOPD) readmission events and to determine whether neutrophil-to-lymphocyte ratio (NLR) and bilirubin levels were associated with readmission after discharge due to AECOPD.

METHODS

A total of 170 patients with AECOPD were included. Patients were stratified into the readmission group if patients had two or more readmissions within 2 years of the previous discharge, and the non-readmission group with one readmission or none within 2 years of the last discharge. Data were collected and compared between groups. The patients were separated by the cutoffs of NLR and bilirubin level. The number of all-cause readmissions within 2 years, time to first COPD-related readmission, 1-year/2-year COPD-related readmission, 1-year/2-year all-cause mortality were compared between groups, respectively.

RESULTS

Compared with the readmission group, patients of the non-readmission group had a shorter length of hospital stay, more systemic corticosteroid use, higher NLR, higher bilirubin levels, and lower eosinophils counts (p < 0.05). NLR and bilirubin levels on admission had significant association with the number of all-cause readmissions (p < 0.05). Lower bilirubin was associated with an increased risk of 1-year COPD-related readmission (OR 5.063) and 2-year COPD-related readmission (OR 4.699).

CONCLUSIONS

For patients with AECOPD, longer hospital stay, and less use of systemic corticosteroids may be associated with a higher risk of readmission. NLR and bilirubin levels on admission may be related to the number of all-cause readmissions. Bilirubin can be regarded as a biomarker to predict readmission rates within 2 years after discharged throughout the course of the disease.

Evaluation of neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio as potential markers for ulcerative colitis: a retrospective study

PURPOSE

Ulcerative colitis (UC) is a chronic idiopathic inflammatory disorder affecting the large intestine. Inflammatory biomarkers in UC are nonspecific, simple and cheap biomarker is needed. Our study aimed to explore the possible relationship of platelet-to-lymphocyte ratio (PLR) and neutrophil-to-lymphocyte ratio (NLR) with the disease activity in UC. Furthermore, the correlation of PLR or NLR with other clinical indicators was evaluated.

METHODS

We retrospectively reviewed the clinical data of UC patients presented to the Affiliated Hospital of Nanjing TCM University. A total of 306 UC patients were included in the study. Clinical characteristics, NLR, PLR, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), fecal calprotectin (FC) and other data were collected.

RESULTS

PLR and NLR were elevated in active UC patients than those in remission. The receiver-operating characteristic (ROC) analysis revealed the optimal cutoff of NLR for active UC was 2.19, with sensitivity and specificity of 78.8 and 65%, respectively. For PLR, the best cut-off value was 147.96, with sensitivity and specificity of 58.3 and 75%, respectively. Both NLR and PLR were positively correlated with CRP, ESR and FC.

CONCLUSIONS

PLR and NLR were elevated in patients with active UC as compared with patients in remission. NLR and PLR could be used in patients with UC as noninvasive markers of disease activity.

The clinical relevance of neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio in chronic obstructive pulmonary disease with lung cancer

Background

Chronic obstructive pulmonary disease (COPD) coexisting with lung cancer is associated with severe mortality and a worse prognosis. Inflammation plays an important role in common pathogenic pathways and disease progression. However, a few studies have identified the clinical value of the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) in COPD with lung cancer, which are systemic inflammatory response markers in the blood. This study aimed to determine the association of the NLR or PLR with clinical characteristics and whether NLR or PLR can be diagnostic markers for COPD with lung cancer.

Methods

Between 2015 and 2021, we conducted a retrospective analysis of 236 COPD patients with lung cancer and 500 patients without lung cancer (control group). Clinical information, blood routine examination, and spirometry results were collected and analyzed. The receiver operating characteristic (ROC) curve was used to identify the best cutoff point of NLR or PLR. Multivariate logistic regression analysis was performed to evaluate the association of NLR or PLR with the diagnosis and prognosis of COPD with lung cancer.

Results

Compared to patients in the COPD-only group, patients in the lung cancer group had a higher percentage of current smoking and emphysema, and it was found that NLR or PLR was significantly higher in the lung cancer group. Multivariate analysis showed that age, smoking status, FEV1%pred, emphysema, NLR, and PLR were independent risk factors for lung cancer development in COPD. Furthermore, the high level of NLR or PLR was associated with age over 70 years old, current smoking status, and ineligible surgery treatment. The level of PLR or NLR markedly increased with hypercoagulation status, the severity of airflow limitation, and advanced progression of lung cancer. Additionally, the ROC analysis also revealed that elevated NLR or PLR was an independent predictor of COPD in lung cancer patients, TNM stages IIIB–IV at first diagnosis in lung cancer, and ineligible surgery in lung cancer patients.

Conclusion

Increased NLR or PLR values might be an important and easily measurable inflammation biomarker to predict the diagnosis and severity of lung cancer with COPD.

The Emerging Clinical Significance of the Red Cell Distribution Width as a Biomarker in Chronic Obstructive Pulmonary Disease: A Systematic Review

There is an intense focus on the identification of novel biomarkers of chronic obstructive pulmonary disease (COPD) to enhance clinical decisions in patients with stable disease and acute exacerbations (AECOPD). Though several local (airway) and circulatory inflammatory biomarkers have been proposed, emerging evidence also suggests a potential role for routine haematological parameters, e.g., the red cell distribution width (RDW). We conducted a systematic literature search in PubMed, Web of Science, and Scopus, from inception to April 2022, for articles investigating the diagnostic and prognostic role of the RDW in stable COPD and AECOPD. The risk of bias was assessed using the Joanna Briggs Institute Critical Appraisal Checklist. Significant associations between the RDW and the presence and severity of disease, outcomes (mortality, hospital readmission), and other relevant clinical parameters (right heart failure, pulmonary arterial hypertension) were reported in 13 out of 16 studies in stable COPD (low risk of bias in 11 studies), and 17 out of 21 studies of AECOPD (low risk of bias in 11 studies). Pending further research, our systematic review suggests that the RDW might be useful, singly or in combination with other parameters, for the diagnosis and risk stratification of patients with stable COPD and AECOPD (PROSPERO registration number: CRD42022348304).

The mechanistic role of neutrophil lymphocyte ratio perturbations in the leading non communicable lifestyle diseases

Inflammation plays a critical role in the development and progression of chronic diseases like type 2 diabetes mellitus, coronary artery disease, and chronic obstructive pulmonary disease. Inflammatory responses are indispensable for pathogen control and tissue repair, but they also cause collateral damage. A chronically activated immune system and the resultant immune dysregulation mediated inflammatory surge may cause multiple negative effects, requiring tight regulation and dampening of the immune response to minimize host injury.  While chronic diseases are characterized by systemic inflammation, the mechanistic relationship of neutrophils and lymphocytes to inflammation and its correlation with the clinical outcomes is yet to be elucidated. The neutrophil to lymphocyte ratio (NLR) is an easy-to-measure laboratory marker used to assess systemic inflammation. Understanding the mechanisms of NLR perturbations in chronic diseases is crucial for risk stratification, early intervention, and finding novel therapeutic targets. We investigated the correlation between NLR and prevalent chronic conditions as a measure of systemic inflammation. In addition to predicting the risk of impending chronic conditions, NLR may also provide insight into their progression. This review summarizes the mechanisms of NLR perturbations at cellular and molecular levels, and the key inflammatory signaling pathways involved in the progression of chronic diseases. We have also explored preclinical studies investigating these pathways and the effect of quelling inflammation in chronic disease as reported by a few in vitro, in vivo studies, and clinical trials.

Are Neutrophil-Lymphocyte, Platelet-Lymphocyte, and Monocyte-Lymphocyte Ratios Prognostic Indicators in Patients With Chronic Obstructive Pulmonary Disease in Intensive Care Units?

Background and objective

Chronic obstructive pulmonary disease (COPD) is a condition in which the expiratory airflow is restricted and is characterized by inflammation. Recently, inflammation-related biomarkers such as neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), and monocyte-lymphocyte ratio (MLR) have been used to predict the prognosis in COPD. The aim of this study was to evaluate the role of biomarkers such as NLR, PLR, and MLR in COPD patients in intensive care and to examine the ability of these markers to predict the prognosis [length of stay in hospital (LOSH), duration of mechanical ventilation (MV), length of stay in ICU (LOS ICU), and mortality].

Methods

A total of 562 patients who were treated in the ICU between 2018 and 2019 were retrospectively reviewed. Among them, 369 were patients with COPD. We evaluated clinical data including patient demographics, Charlson Comorbidity Index (CCI), Acute Physiology and Chronic Health Evaluation II (APACHE II) score, Sequential Organ Failure Assessment (SOFA) score, LOS ICU, LOSH, duration of MV, as well as NLR, PLR, and MLR values. Data on patient deaths (30-day mortality) was obtained from the Death Notification System.

Results

Age, LOSH, CCI, and SOFA were found to predict mortality in COPD patients. In cases with mortality, age, inotropic use, MV duration, LOS ICU, APACHE II, CCI, SOFA, lymphocyte count, neutrophil count, platelet count, monocyte count, NLR, PLR, and MLR levels were statistically significantly higher than those in cases without mortality. There was a positive and low statistically significant relationship of NLR, PLR, and MLR with prognostic factors like MV duration, APACHE II scores, and SOFA scores.

Conclusion

The NLR, PLR, and MLR values may be used as prognostic indicators in COPD patients in intensive care. Although there are many studies endorsing the use of biomarkers such as NLR, PLR, and MLR as prognostic indicators, further comparative studies on this subject are still required to gain deeper insights into the topic.

What Are the Most Effective Factors in Determining Future Exacerbations, Morbidity Weight, and Mortality in Patients with COPD Attack?

Background and Objectives: This study aimed to investigate the important factors that affect COPD prognosis. Materials and Methods: We included 160 hospitalized patients with COPD exacerbation in the study. The hemoglobin (HB), hematocrit (HCT), leukocytes, red cell distribution width (RDW), mean platelet volume, platelet distribution width, plateletcrits, platelets, neutrophil/lymphocyte ratio, platelet/lymphocyte ratio, eosinophils, uric acid, albumin, C-reactive protein (CRP), procalcitonin, arterial blood gases (PO2 and PCO2), pulmonary function test (FEV1 and FVC), echocardiography (ejection fraction-EF), Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage, Modified Medical Research Council (mMRC) and Borg scales, Charlson comorbidity index, body mass index (BMI), and the length of hospital stay were examined on the first day of hospitalization. Admission to the hospital with a new attack, hospitalization in the intensive care unit (ICU), and mortality during the six months after discharge were evaluated. Results: High CRP and procalcitonin levels were observed in the group with a long hospital stay. In the mortality group, the HB, HCT, BMI, and PO2 values were significantly lower than in the group without mortality, while the age and GOLD stage were higher. The age, Borg and mMRC scores, number of exacerbations experienced in the previous year, RDW, eosinophil count, and PCO2 were significantly higher in the ICU group than that without an ICU stay. The HCT and EF values were lower in the ICU group than that without an ICU stay. The FEV1 and FVC values were significantly lower in the follow-up attack group than those without a follow-up attack. The duration of COPD and the number of attacks that were experienced in the previous year were high. Conclusion: Scoring combining selected biomarkers and other factors is a strong determinant of the prognosis.

Evaluation of the prognostic value of neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio in acute exacerbation of chronic obstructive pulmonary disease

Background:

The present study aimed at determining and comparing the prognostic value and the relationship of neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios (PLRs) with acute exacerbation of chronic obstructive pulmonary disease (AECOPD).

Materials and Methods:

The present case–control study was performed on 100 chronic obstructive pulmonary disease patients and 100 healthy subjects (controls). Age, gender, and laboratory results of complete blood count tests including lymphocyte count, neutrophil count, platelet count, hemoglobin level, neutrophil-to-lymphocyte ratio (NLR), PLR, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) were obtained from the patient report and then recorded. The mentioned information was also completed for the control group. Following hospitalization, the patients that were discharged with clinically stable general status were re-examined, and the aforementioned laboratory information was rerecorded.

Results:

The results of the present study revealed that NLR with the sensitivity and specificity of 83.00% (74.2%–89.8%) and 93.00% (86.1%–97.1%) (cutoff value of 2.3), PLR with the sensitivity and specificity of 56.00% (46.0%–66.3%) and 83.00% (74.2%–89.8%) (cutoff value of 135.8), white blood cell (WBC) with the sensitivity and specificity of 69.00% (57.7%–77.8%) and 78.00% (68.6%–85.7%) (cutoff value of 8.5 × 103 μl), ESR with the sensitivity and specificity of 84.00% (75.3%–90.6%) and 99.00% (94.6%–100.0%) (cutoff value of 7.8), and CRP with the sensitivity and specificity of 52.00% (41.8%–62.1%) and 81.00% (71.9%–88.2%) (cutoff value of 1.9), respectively, had a significant prognostic value of AECOPD (P < 0.001). In addition to NLR had higher area under the curve (AUC) than PLR, WBC, and CRP. Therefore NLR had a better diagnostic value than the above three markers (P < 0.001). ESR also has higher AUC levels compared to PLR, WBC, and CRP and has a statistically better diagnostic value than them (P < 0.001), but did not differ significantly from ESR (difference between AUC: 0.02; P = 0.059).

Conclusion:

According to the results of the current study, NLR and PLR had a significant direct relationship with the two main markers of ESR and CRP, and both ratios had a significant prognostic value in AECOPD.

Can red blood cell distribution width (RDW) level predict the severity of acute exacerbation of chronic obstructive pulmonary disease (AECOPD)?

BACKGROUND

Elevated red blood cell distribution width (RDW) levels were associated with mortality in patients with stable chronic obstructive lung pulmonary diseases (COPD). There are limited data about RDW levels in acute exacerbation of COPD (AECOPD).

AIM/OBJECTIVE

The association of the RDW levels with the severity of AECOPD was evaluated according to admission location, (outpatient-clinic, ward and intensive care unit (ICU)).

METHODS

Cross sectional retrospective study was designed in tertiary care hospital for chest diseases in 2015. Previously COPD diagnosed patients admitted to hospital outpatient-clinic, ward and ICU due to AECOPD were included in the study. Patients demographics, RDW, biomarkers (CRP, RDW, Neutrophil to lymphocyte ratio (NLR), platelet to mean platelet volume (PLT-MPV)) C-CRP, biochemistry values were recorded from hospital electronic system. RDW values were subdivided below 0.11% (low), above and equal 0.15% (high) and between 0.11%-0.15% (normal). Neutrophil to lymphocyte ratio (NLR) and platelet to mean platelet volume (PLT-MPV) were also calculated. Biomarker values were compared according to where AECOPD was treated.

RESULTS

2771 COPD patients (33% female) and 1429 outpatients-clinic, 1156 ward and 186 ICU were enrolled in the study. The median RDW values in outpatients-clinic, ward and ICU were 0.16 (0.09-0.26), 0.07 (0.01-0.14) and 0.01 (0.00-0.07) respectively (P < .001). In outpatient to ward and ICU, low RDW values were significantly increased (31%, 66%, 83%, respectively) and high RDW values significantly decreased (54%, 24%, 10%) (P < .001). According to attack severity, low RDW values were determined.

CONCLUSION

Patients with AECOPD, lower RDW values should be considered carefully. Lower RDW can be used for decision of COPD exacerbation severity and follow up treatment response.

Neutrophil-to-lymphocyte ratio, blood eosinophils and COPD exacerbations: a cohort study

Background

Blood neutrophil-to-lymphocyte ratio (NLR) and blood eosinophils (B-Eos) are emerging biomarkers in COPD. This study examined whether they could predict acute exacerbations of COPD (AECOPDs), and determined their longitudinal stability.

Methods

In this closed cohort study, Swedish subjects with spirometry-verified COPD attended three yearly visits in a stable phase of the disease. Blood cell counts, spirometry and questionnaire-assessed AECOPD-history (worsening of COPD leading to an unscheduled visit and/or use of antibiotics and/or oral corticosteroids) were collected at each visit.

Results

Of 466 included subjects 57% were female. Baseline mean±sd forced expiratory volume in 1 s was 58±17% predicted. High NLR (≥3.0) was more common in subjects with previous AECOPDs than in those without (33.5% versus 20.4%, p=0.002). In two-level mixed-effects logistic regression models adjusted for confounders, NLR as a continuous variable (OR 1.20, 95% CI 1.04–1.38) and B-Eos ≥300 cells·µL⁻¹ (OR 1.54, 95% CI 1.06–2.24) were associated with future AECOPDs. In 386 subjects with blood cell data available at all three visits, the intraclass correlation coefficient for NLR was 0.61 (95% CI 0.56–0.66) and for B-Eos 0.69 (95% CI 0.64–0.73). NLR was persistently ≥3.0 in 10.6% and B-Eos was persistently ≥300 cells·µL⁻¹ in 15.3%.

Conclusions

Stable phase NLR and B-Eos were associated with future AECOPDs. NLR on its own is probably not useful to predict AECOPDs but might be included in a risk scoring index. A minority of subjects with COPD had persistently elevated stable-phase NLR or B-Eos, and the biomarkers showed fair longitudinal reliability.

Neutrophil-to-lymphocyte ratio and blood eosinophils in stable-phase COPD are associated with future exacerbations and show fair longitudinal reliabilityhttps://bit.ly/3CAS1jY

Neutrophil-to-Lymphocyte Ratio as a Factor Predicting Radiotherapy Induced Oral Mucositis in Head Neck Cancer Patients Treated with Radiotherapy

BACKGROUND

The objective of this research conducted in head and neck cancer (HNC) patients was the assessment of the relationship between neutrophil-to-lymphocyte ratio (NLR) and the incidence of severe radiotherapy (RT) induced oral mucositis (OM), as well as overall survival (OS).

METHODS

The study involved 207 patients in advanced stages (III-IV) of HNC. RTOG/EORTC scale was used to assess OM. The pre-treatment NLR was specified as the absolute neutrophil count divided by the absolute lymphocyte count.

RESULTS

Starting from second to seventh week of RT, we observed a significant, positive correlation between NLR values and OM grade. From the second to seventh week of RT, higher NLR values were related with significant increases (from 2- to over 24-fold) in the risk of occurrence of more severe OM (multivariate analysis confirmed its independent influence). Moreover, multivariate analysis for survival revealed that both higher TNM stage (HR = 1.84; p = 0.0043) and higher NLR values (HR = 1.48; p = 0.0395) were independent prognostic factors.

CONCLUSION

NLR is a simple and accurate parameter that is useful in the evaluation of the risk of more severe OM, as well as an independent prognostic factor of OS in patients subjected to RT due to HNC.

Area under flow-volume loop may predict severe exacerbation in COPD patients with high grade of dyspnea

OBJECTIVE

Exacerbations in patients with COPD may still be unpredictable, although the general risk factors have been well defined. We aimed to determine the role of a novel parameter, area under flow-volume loop, in predicting severe exacerbations.

METHODS

In this single-centre retrospective cohort study, 81 COPD patients over 40 years of age with high grade of dyspnea (having a CAT score of ≥10) and a history of ≥1 moderate exacerbation in the previous year were included. Area under flow-volume curve (AreaFE%) was obtained from pulmonary function test graph and calculated from Matlab programme. Univariate and multivariate logistic regression analyses were performed to determine independent risk factors of the severe exacerbation.

RESULTS

Patients with severe exacerbation (n = 70, 86.4 %) were older. They had lower FEV1%, FVC%, 6MWD, AreaFE% and higher CAT score than patients without exacerbation. After performing multivariate analysis, high CAT score and low AreaFE% value were found to be independent risk factors for severe exacerbation (OR: 1.12, 95 % CI: 1.065-1.724; p = 0.01 and OR: 1.18, 95 % CI: 0.732-0.974; p = 0.02).

CONCLUSIONS

We found that a low AreaFE% value was an independent risk factor in addition to a high CAT score and these both have an excellent discriminative ability in predicting the risk of severe exacerbation.

Neutrophil-to-Lymphocyte Ratio and Treatment Failure in Peritoneal Dialysis-Associated Peritonitis

Objective: We sought to explore if there is an association between neutrophil-to-lymphocyte ratio (NLR) and treatment failure in patients with peritoneal dialysis-associated peritonitis (PDAP).

Methods: Our cohort involved 337 episodes of PDAP experienced by 202 patients who were undergoing continuous ambulatory peritoneal dialysis at a single center from 1 July 2013 to 30 June 2018. The exposures were log-transformed NLR and a categorical variable grouped by the tertiles of NLR levels (T1, <3.75; T2, 3.75–6.53; and T3, >6.53) at baseline. Generalized estimating equation (GEE) and restricted cubic spline (RCS) analyses were done to determine the association between NLR and treatment failure, defined as catheter removal or all-cause mortality during therapy.

Results: After adjusting for other potential predictors, the log-transformed NLR exhibited an incremental relationship with the risk of treatment failure (odds ratio, 1.82; 95% confidence interval, 1.05–3.15). RCS analyses showed that the relationship was positively and linearly correlated (P for nonlinearity = 0.104). As a three-level categorical variable, in reference to T1, the T3 of NLR showed a 3.41-fold increased venture of treatment failure in fully adjusted model. Subgroup analyses suggested that the prognostic relevance of NLR in PDAP was particularly significant in gram-negative peritonitis.

Conclusions: A greater level of NLR at baseline was remarkably associated with a higher incidence of treatment failure among PDAP episodes regardless of other potential risk factors.

Predictive Value of Neutrophil/Lymphocyte Ratio (NLR) on Cardiovascular Events in Patients with COVID-19

BACKGROUND

The research on the association between coronavirus disease 2019 (COVID-19) and cardiovascular disease (CVD) is still insufficient.

AIM

This study aimed to investigate the association between neutrophil/lymphocyte ratio (NLR) and risk of cardiovascular events in patients with COVID-19.

METHODS

Our study included 159 patients with COVID-19 who were measured for NLR value within the first 24 hours of admission. They were followed up for 6 months after discharge and then the relationship between levels of NLR and risk of cardiovascular events was assessed.

RESULTS

In all included patients with COVID-19, NLR values in patients with cardiovascular events [16.28 (4.95-45.18)] were significantly higher than patients without cardiovascular events [4.75 (2.60-7.47)]. A multivariate logistic regression model revealed that elevated NLR value [increased per SD, 2.41 (1.43-4.29), P<0.001; increased 1 of NLR, 2.05 (1.33-4.01), P=0.010] was significantly and independently associated with increased risk of CVD history on admission after adjustment of related confounding factors. Then, Cox regression analysis revealed that elevated NLR value had a significant association with increased risk of cardiovascular events [increased per SD, 2.36 (1.42-4.36), P<0.001; Increased 1 of NLR, 2.00 (1.30-3.97), P=0.014] after adjustments of these same confounding factors. Furthermore, the ROC curve suggested that NLR value (AUC=0.803, 95% CI=0.731-0.875, P<0.001, sensitivity 81.2%, and specificity 82.6%) has a good predictive value for cardiovascular events during follow-up.

CONCLUSION

High NLR value was clinically associated with elevated risk of cardiovascular events in patients with COVID-19, which might be a potential biomarker for predicting cardiovascular events in the current COVID-19 pandemic.

Epithelial Barrier Dysfunction in Chronic Respiratory Diseases

Mucosal surfaces are lined by epithelial cells, which provide a complex and adaptive module that ensures first-line defense against external toxics, irritants, antigens, and pathogens. The underlying mechanisms of host protection encompass multiple physical, chemical, and immune pathways. In the lung, inhaled agents continually challenge the airway epithelial barrier, which is altered in chronic diseases such as chronic obstructive pulmonary disease, asthma, cystic fibrosis, or pulmonary fibrosis. In this review, we describe the epithelial barrier abnormalities that are observed in such disorders and summarize current knowledge on the mechanisms driving impaired barrier function, which could represent targets of future therapeutic approaches.

High Neutrophil-to-Lymphocyte Ratio and Platelet-to-Lymphocyte Ratio Are Associated with Poor Survival in Patients with Hemodialysis

Background

The neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are markers for systemic inflammation condition. Although NLR has emerged as a risk factor for poor survival in end-stage renal disease (ESRD) patients, the relationship between PLR and mortality is still unknown. We aimed to explore the interaction of NLR and PLR in predicting mortality in hemodialysis (HD) patients.

Method

We enrolled 360 HD patients for a 71-month follow-up. The endpoint was all-cause and cardiovascular (CV) mortality. Pearson correlation analysis was conducted to evaluate the relationship between factors and NLR or PLR. Kaplan-Meier curves and Cox proportional analysis were used to assess the prognostic value of NLR and PLR.

Results

NLR was positively correlated with neutrophil and negatively correlated with lymphocyte, hemoglobin, and serum albumin. PLR was positively correlated with neutrophil and platelet and negatively correlated with lymphocyte and hemoglobin. In multivariate Cox regression, a higher NLR level was independently associated with all-cause mortality (OR 2.011, 95% CI 1.082-3.74, p = 0.027), while a higher PLR level might predict CV mortality (OR 2.768, 95% CI 1.147-6.677, p = 0.023) in HD patients.

Conclusion

NLR and PLR are cheap and reliable biomarkers for all-cause and CV mortality to predict survival in HD patients.

The predictive value of neutrophil-to-lymphocyte ratio for chronic obstructive pulmonary disease: a systematic review and meta-analysis

INTRODUCTION

There was inconsistent results regarding the associations of neutrophil to lymphocyte ratio (NLR) with the progression and prognosis of chronic obstructive pulmonary disease (COPD).

AREAS COVERED

This paper assess the role of NLR on the progression and prognosis of COPD using a meta-analytic approach. PubMed, EmBase, and the Cochrane library were systematically searched. The pooled weighted mean differences and odds ratios with 95% confidence intervals were applied for continuous and categorical variables using the random-effects model.

EXPECT COMMENATRY

NLR was significantly high when comparing COPD patients to healthy individuals, and acute exacerbation COPD to stable COPD. Moreover, elevated NLR were significantly associated with higher risk of mortality and exacerbation.

Platelet Count and Platelet Indices in Patients with Stable and Acute Exacerbation of Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis

Platelets play an important role in the pathophysiology of chronic obstructive pulmonary disease (COPD) by mediating thrombotic, inflammatory, and immune processes in the lung. We conducted a systematic review and meta-analysis of studies investigating the platelet count and three platelet indices, mean platelet volume (MPV), platelet distribution width (PDW), and platelet to lymphocyte ratio (PLR) in stable COPD vs. non-COPD patients and in stable COPD vs. acute exacerbation of COPD (AECOPD) patients (PROSPERO registration number: CRD42021228263). PubMed, Web of Science, Scopus and Google Scholar were searched from inception to December 2020. Twenty-seven studies were included in the meta-analysis, 26 comparing 4,455 stable COPD patients with 7,128 non-COPD controls and 14 comparing 1,251 stable COPD with 904 AECOPD patients. Stable COPD patients had significantly higher platelet counts (weighted mean difference, WMD = 13.39 x10⁹/L, 95% CI 4.68 to 22.11 x10⁹/L; p < 0.001) and PLR (WMD = 59.52, 95% CI 29.59 to 89.44; p < 0.001) than non-COPD subjects. AECOPD patients had significantly higher PLR values than stable COPD patients (WMD = 46.03, 95% CI 7.70 to 84.35; p = 0.02). No significant differences were observed in MPV and PDW. Between-study heterogeneity was extreme. In sensitivity analysis, the effect size was not modified when each study was sequentially removed. The was no evidence of publication bias. In our meta-analysis, specific platelet biomarkers were associated with stable COPD (platelet count and PLR) and AECOPD (PLR). However, the observed heterogeneity limits the generalizability of the findings. Further studies are required to determine their prognostic utility and the effects of targeted interventions in COPD.

Correlation of Low Levels of α-1 Antitrypsin and Elevation of Neutrophil to Lymphocyte Ratio with Higher Mortality in Severe COVID-19 Patients

Background

Variations in COVID-19 prevalence, severity, and mortality rate remain ambiguous. Genetic or individual differences in immune response may be an explanation. Moreover, hyperinflammation and dysregulated immune response are involved in the etiology of severe forms of COVID-19. Therefore, the aim of the present study was to analyze serum alpha-1 antitrypsin (AAT) levels, as an acute-phase plasma protein with immunomodulatory effect and neutrophil to lymphocyte ratio (NLR) as a marker of inflammation response in severe COVID-19 illness.

Methods

In this retrospective observational cohort study, 64 polymerase chain reaction (PCR) positive COVID-19 hospitalized patients were studied for AAT, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), troponin, complete blood count (CBC), random blood sugar, serum glutamate oxaloacetate transaminase (SGOT), serum glutamate pyruvate transaminase (SGPT), and arterial oxygen saturation (O2sat) at admission and during hospitalization.

Results

The results showed that hospitalized patients with COVID-19 had low serum levels of AAT and high CRP levels at the first days of hospitalization. In particular, the percentages of individuals with low, normal, and high AAT levels were 7.80%, 82.80%, and 9.40%, respectively, while high and low values of CRP accounted for 86.70% and 13.30% of patients. Most of the patients had an upward neutrophil to lymphocyte ratio (NLR) trend, with a higher mortality rate (p < 0.05) and troponin levels (p < 0.05). However, comorbidities, CRP alterations, ESR alterations, nonfasting blood sugar, SGOT, SGPT, O2sat, RBC, and PLT values were not significantly different between the NLR downward and upward trend groups.

Conclusions

The current study revealed that severe COVID-19 patients had low serum AAT levels related to CRP values. Therefore, AAT response may be considered as a new mechanism by which some COVID-19 patients show immune dysregulation and more severe symptoms.

Relationship of Red Cell Index with the Severity of Chronic Obstructive Pulmonary Disease

Background

We aimed to investigate the association between red cell index (RCI) and the severity of Chronic Obstructive Pulmonary Disease (COPD), and compare predictive value of RCI, neutrophil–lymphocyte ratio (NLR) and platelet–lymphocyte ratio (PLR) for the severity of COPD.

Methods

A total of 207 participants were recruited (100 COPD patients and 107 healthy controls). COPD patients were divided into two groups according to the optimal cut-off value of RCI determined by the receiver operating characteristic (ROC) curve. Pearson’s correlation test, logistic regression analysis and other tests were performed.

Results

Compared with low RCI group, the forced expiration volume in 1 second (FEV₁) and FEV₁ in percent of the predicted value (FEV₁%) in high RCI group were lower (p = 0.016, p = 0.001). There was a negative correlation between RCI and FEV₁% (r = −0.302, p = 0.004), while no correlation between FEV₁% and NLR as well as PLR were found. RCI showed higher predictive value than NLR and PLR for predicting Global Initiative for Chronic Obstructive Lung Disease classification (GOLD), with a cut-off value of 1.75 and area under the curve (AUC) of 0.729 (p = 0.001). Multivariate logistic regression analysis proved that RCI was an independent factor for lung function in COPD patients (odds ratio [OR] = 4.27, 95% CI: 1.57–11.63, p = 0.004).

Conclusion

RCI is a novel biomarker that can better assess pulmonary function and severity of COPD than NLR and PLR. Higher RCI is related to deterioration of pulmonary function.

Prevalence and characteristics of venous thromboembolism in severe exacerbation of chronic obstructive pulmonary disease in a tertiary care hospital in India

Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) carries a high risk of venous thromboembolism (VTE). Pulmonary embolism (PE) and AECOPD increase the mortality and morbidity risk associated with each other. Racial and ethnic differences in VTE risk have been documented in multiple studies. However, there is a dearth of reliable Indian data on the same. This study was planned to find the prevalence of VTE in the setting of severe AECOPD in a tertiary care hospital in India and to identify the clinical, laboratory and radiological characteristics of VTE in severe AECOPD. A total of 156 consecutive patients admitted with severe AECOPD and meeting the specified inclusion and exclusion criteria were recruited. Thorough workup of all patients was done including ABG, serum D dimer, ECG, compression ultrasound of lower limbs and 2-D echocardiography. Patients with high pre-test probability score, or intermediate pre-test probability score at presentation with serum D dimer above the age adjusted cut-off underwent computerised tomography pulmonary angiography (CTPA).  Results were analysed using SPSS version 23.  Sixteen (10.3%) patients had VTE, 15 (93.75%) of them being cases of isolated PE. Female gender, higher cumulative past exposure to corticosteroid, higher alveolar-arterial gradient, right ventricular dysfunction, and higher mean pulmonary artery pressure were associated with increased risk for VTE. The prevalence of VTE in AECOPD in this study among an Indian population is higher than among other Asians, but lower than among the Blacks, the Caucasians and the Middle-East ethnicities. Since a vast majority of VTE presents as PE without DVT in the setting of AECOPD, the absence of deep vein thrombosis of lower limbs does not rule PE in the setting.

Nicotine promotes breast cancer metastasis by stimulating N2 neutrophils and generating pre-metastatic niche in lung

Smoking has a profound impact on tumor immunity, and nicotine, which is the major addictive component of smoke, is known to promote tumor progression despite being a non-carcinogen. In this study, we demonstrate that chronic exposure of nicotine plays a critical role in the formation of pre-metastatic niche within the lungs by recruiting pro-tumor N2-neutrophils. This pre-metastatic niche promotes the release of STAT3-activated lipocalin 2 (LCN2), a secretory glycoprotein from the N2-neutrophils, and induces mesenchymal-epithelial transition of tumor cells thereby facilitating colonization and metastatic outgrowth. Elevated levels of serum and urine LCN2 is elevated in early-stage breast cancer patients and cancer-free females with smoking history, suggesting that LCN2 serve as a promising prognostic biomarker for predicting increased risk of metastatic disease in female smoker(s). Moreover, natural compound, salidroside effectively abrogates nicotine-induced neutrophil polarization and consequently reduced lung metastasis of hormone receptor-negative breast cancer cells. Our findings suggest a pro-metastatic role of nicotine-induced N2-neutrophils for cancer cell colonization in the lungs and illuminate the therapeutic use of salidroside to enhance the anti-tumor activity of neutrophils in breast cancer patients.

Smoking is known to impact tumor immunity and promote tumor progression. Here, the authors show that chronic nicotine exposure promotes the lung pre-metastatic niche formation by recruiting pro-tumor N2-neutrophils that release lipocalin-2.

Impact of Combined Chronic Obstructive Pulmonary Disease Status and Systemic Inflammation on Outcome of Advanced NSCLC: Multicenter Retrospective Cohort Study

Background

In patients with non-small cell lung cancer (NSCLC), both chronic obstructive pulmonary disease (COPD) and systemic inflammatory biomarkers, such as neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR), have significant association with prognosis. NLR and PLR also predict mortality in patients with COPD alone. A combination of the two parameters may be helpful in a more individualized approach for predicting prognosis in NSCLC.

Methods

Medical records of patients with stage IIIB and IV NSCLC from January 2012 to January 2018 in seven university hospitals were reviewed. Patients were categorized into four subgroups based on pulmonary function test results and cutoffs for NLR or PLR.

Results

A total of 277 patients were evaluated and categorized into non-COPD and COPD groups; 194 patients were in the non-COPD group and 83 patients were in the COPD group. The non-COPD group showed significantly longer overall survival (OS) compared with the COPD group (P = 0.019). Median survival was significantly different between high/low PLR groups (P < 0.001), between high/low NLR groups (P = 0.001), and between high/low c-reactive protein (CRP) groups (P < 0.001). PLR, NLR and CRP showed significant correlations with each other. PLR showed a significant negative linear correlation with FVC (absolute) (r = −0.149, P = 0.015), FVC (%) (r = −0.192, P = 0.002), DLCO (absolute) (r = −0.271, P < 0.001), DLCO (%) (r = −0.139, P = 0.032), and NLR (r = 0.718, P < 0.001). In the multivariate analysis, the high PLR, COPD sub-group showed significantly higher risk for mortality (HR 2.066 (1.175–3.633), P = 0.012) compared with the low-PLR non-COPD group. However, COPD-NLR subtype was not an independent predictor for OS.

Conclusion

A combination of COPD status and PLR may be a cost-effective and readily available prognostic marker in patients with advanced NSCLC.

Adiponectin is Associated with Neutrophils to Lymphocyte Ratio in Patients with Chronic Obstructive Pulmonary Disease

Disproportionate systemic inflammation in chronic obstructive pulmonary disease (COPD) is associated with declining lung functions and comorbidities. Neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) have emerged as valuable markers of the systemic inflammation in COPD. Adiponectin (Acpr30) circulates in serum as complexes of different molecular weight (HMW, MMW, LMW) with multifaceted metabolic and anti-inflammatory properties implicated in airway pathophysiology. We aimed to investigate the association between Acpr30 and its oligomers and the NLR and PLR in COPD patients. Seventy stable COPD patients were enrolled. Acrp30 serum levels and the HMW oligomers as well as hematological parameters and their ratio were evaluated. Both NLR and PLR are associated with lower BMI. Interestingly, total Acpr30 is negatively associated with NLR but not with PLR; after adjusting for age, BMI and FEV1, Acpr30 was independently associated with NLR. Conversely, HMW Acpr30 and HMW/Acpr30 ratio were positively correlated to NLR. The association of Acpr30, HMW Acpr30 and HMW/totalAcpr30 ratio with NLR but not with PLR in COPD patients indicates that Acrp30 oligomerization could represent a biological mechanism interfering with systemic inflammation in COPD. Further studies in larger cohorts of patients are required to confirm these results.

The Relationship of Lymphocyte to High-Density Lipoprotein Ratio with Pulmonary Function in COPD

Purpose

This study aimed to explore the relation between lymphocyte to high-density lipoprotein ratio (LHR) and pulmonary function of chronic obstructive pulmonary disease (COPD) patients compared with neutrophil–lymphocyte ratio (NLR) and platelet–lymphocyte ratio (PLR).

Patients and Methods

In total, 154 participants (n = 77 with COPD and n = 77 without COPD) were recruited. LHR, NLR, PLR, lung function and other data were collected and compared. Pearson’s correlation test and the receiver operating characteristics curves were used to compare the utility of LHR, NLR and PLR. Besides, univariate and multivariate logistic regression analyses were conducted.

Results

COPD patients with poorer lung function had a lower LHR level (P < 0.001). In low LHR group, more patients underwent greater airflow limitation than the other group (P = 0.006). LHR positively correlated with forced expiratory volume in 1 second in percent of the predicted value (FEV₁%) (r = 0.333, P = 0.003). At a cut-off value of 2.08, the sensitivity and specificity of LHR in predicting FEV₁% < 50 were 93.2% and 55.6%, respectively, with an AUC of 0.770 (P = 0.001) better than NLR and PLR. Based on logistic regression analyses, it was proved that LHR was associated with decreased risk of FEV₁ <50% predicted in COPD patients (odds ratio = 0.198, 95% CI: 0.048–0.811, P = 0.024).

Conclusion

In contrast with NLR and PLR, LHR has higher accuracy for predicting pulmonary function in COPD; lower LHR level is independently associated with poorer pulmonary function.

COVID-19 Susceptibility in chronic obstructive pulmonary disease

In barely nine months, the pandemic known as COVID-19 has spread over 200 countries, affecting more than 22 million people and causing over than 786 000 deaths. Elderly people and patients with previous comorbidities such as hypertension and diabetes are at an increased risk to suffer a poor prognosis after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Although the same could be expected from patients with chronic obstructive pulmonary disease (COPD), current epidemiological data are conflicting. This could lead to a reduction of precautionary measures in these patients, in the context of a particularly complex global health crisis. Most COPD patients have a long history of smoking or exposure to other harmful particles or gases, capable of impairing pulmonary defences even years after the absence of exposure. Moreover, COPD is characterized by an ongoing immune dysfunction, which affects both pulmonary and systemic cellular and molecular inflammatory mediators. Consequently, increased susceptibility to viral respiratory infections have been reported in COPD, often worsened by bacterial co-infections and leading to serious clinical outcomes. The present paper is an up-to-date review that discusses the available research regarding the implications of coronavirus infection in COPD. Although validation in large studies is still needed, COPD likely increases SARS-CoV-2 susceptibility and increases COVID-19 severity. Hence, specific mechanisms to monitor and assess COPD patients should be addressed in the current pandemic.

Neutrophils to Lymphocyte Ratio as a Biomarker in Bronchiectasis Exacerbation: A Retrospective Study

Introduction

Bronchiectasis is a disorder resulting mainly from bronchial inflammation caused by recurrent or chronic infections. It is characterized by permanently dilated airways due to bronchial wall destruction. Exacerbations have a key role in bronchiectasis as they are associated with a negative impact on patient prognosis. Exacerbations are generally infectious events caused mostly by bacterial microorganisms. Infective or inflammatory agents cause neutrophil recruitment into the airways, which leads to proteolytic enzymes such as neutrophil elastase and matrix metalloproteinases release, resulting in airway matrix destruction. Neutrophil to lymphocyte ratio (NLR) is used as a biomarker of inflammation. It is calculated by dividing the number of neutrophils by the number of lymphocytes. Our aim is to evaluate Neutrophils to Lymphocyte Ratio in patients with bronchiectasis exacerbation and its correlation to microbiological data.

Methods 

The study involved patients with a diagnosis of bronchiectasis based on high-resolution computerised tomography (HRCT) of the chest who fulfilled the criteria of bronchiectasis exacerbation. Complete blood counts with differential counts, which included total white blood cells, neutrophils and lymphocytes, were obtained. NLR and C-reactive protein (CRP) levels were measured in patients with bronchiectasis exacerbation and in healthy controls. NLR was calculated as the ratio of the neutrophils to lymphocytes. The mean NLR values in patients with bronchiectasis exacerbation were compared to mean NLR values in healthy controls. The NLR values were compared to CRP levels in patients with bronchiectasis exacerbation. Sputum cultures were performed in all patients. The mean NLR values in patients with positive sputum cultures were compared with mean NLR values in patients with negative sputum cultures, and mean NLR values in patients with isolated Pseudomonas aeruginosa in sputum cultures were compared to mean NLR values in patients with other infectious agents isolated.

Results

The study population consisted of 80 patients with bronchiectasis exacerbation - 54 males and 26 females - with a mean age of 77.3±8.4 years, and 64 healthy controls - 36 males and 28 females - with a mean age of 62.9±15.3 years. The mean CRP levels in patients with bronchiectasis exacerbation were 75.03±73.87 mg/l. The mean NLR value in patients with bronchiectasis exacerbation was 9.2±7.8 and the mean NLR value of controls was 3.1±2.9 (p<0.001). The NLR values in patients with bronchiectasis exacerbation had no linear correlation with CRP values in these patients (r=0.002, p=0.992). Fifty-two patients had positive sputum cultures and 28 patients had negative sputum cultures. The mean NLR value in patients with positive sputum cultures was 10.5±9.1, and in patients with negative sputum cultures, it was 6.7±3.6 (p<0.012). The mean NLR value in patients with P.aeruginosa was 10.1±9.5, and in patients with other microorganisms isolated, it was 10.8±8.9 (p=0.784).

Conclusions

Neutrophil to lymphocyte ratio values are statistically greater in patients with bronchiectasis exacerbation compared to healthy controls. There is no linear correlation between NLR and CRP in these patients. NLR values are statistically greater in patients with positive sputum cultures compared to those with negative sputum cultures. Therefore, NLR can be used for predicting positive cultures in patients with bronchiectasis exacerbation.

Association of Neutrophil to Lymphocyte Ratio With Pulmonary Function in a 30-Year Longitudinal Study of US Veterans

IMPORTANCE

Chronic obstructive pulmonary disease (COPD) is a critical public health burden. The neutrophil to lymphocyte ratio (NLR), an inflammation biomarker, has been associated with COPD morbidity and mortality; however, its associations with lung function decline and COPD development are poorly understood.

OBJECTIVE

To explore the associations of NLR with lung function decline and COPD risks.

DESIGN, SETTING, AND PARTICIPANTS

This longitudinal cohort study included white male veterans in the US with more than 30 years of follow-up to investigate the associations of NLR with lung function, COPD, and hypomethylation of cg05575921, the top DNA methylation marker of lung function changes in response to tobacco smoking. This study included 7466 visits from 1549 participants, each examined up to 13 times between 1982 and 2018. A subgroup of 1411 participants without COPD at baseline were selected to analyze the association of NLR with incident COPD. Data were analyzed from September 2019 to January 2020.

EXPOSURES

The primary exposure was NLR, which was estimated using automated whole blood cell counts based on a blood sample collected at each visit. The methylation level of cg05575921 was measured in blood DNA from a subgroup of 1228 visits.

MAIN OUTCOMES AND MEASURES

The outcomes of interest were lung function, measured as forced respiratory volume in the first second (FEV1) in liters, forced vital capacity (FVC) in liters, percentage of FVC exhaled in the first second (FEV1/FVC), and maximal midexpiratory flow rate (MMEF) in liters per minute and COPD status, defined as meeting the Global Initiative for Chronic Obstructive Lung Diseases stage II (or higher) criteria. Both outcomes were measured as each visit.

RESULTS

Among 1549 included men (mean [SD] age, 68.3 [9.3] years) with 7466 visits from 1982 to 2018, a 1-unit increase in NLR was associated with statistically significant mean (SE) decreases of 0.021 (0.004) L in FEV1, 0.016 (0.005) L in FVC, 0.290% (0.005) L in FVC, 0.290% (0.065%) in FEV1/FVC, and 3.65 (0.916) L/min MMEF. Changes in NLR up to approximately 10 years were associated with corresponding longitudinal changes in lung function. Furthermore, this increase in NLR was associated with 9% higher odds of COPD (odds ratio, 1.09 [95% CI, 1.03-1.15]) for all visits and 27% higher risk of incident COPD (odds ratio, 1.07 [95% CI, 1.07-1.51]) for participants without COPD at baseline. Additionally, a 1-unit increase in NLR was associated with a mean (SE) decrease of 0.0048 (0.0021 in cg05575921 hypomethylation, which may mediate the adverse association of NLR-related inflammation on lung function.

CONCLUSIONS AND RELEVANCE

These findings suggest that NLR may be a clinically relevant biomarker associated with high risk of lung function impairment and COPD alone or in combination with DNA methylation profiles.

Cutaneous lewisite exposure causes acute lung injury

Lewisite is a strong vesicating and chemical warfare agent. Because of the rapid transdermal absorption, cutaneous exposure to lewisite can also elicit severe systemic injury. Lewisite (2.5, 5.0, and 7.5 mg/kg) was applied to the skin of Ptch1^+/- /SKH-1 mice and acute lung injury (ALI) was assessed after 24 hours. Arterial blood gas measurements showed hypercapnia and hypoxemia in the lewisite-exposed group. Histological evaluation of lung tissue revealed increased levels of proinflammatory neutrophils and a dose-dependent increase in structural changes indicative of injury. Increased inflammation was also confirmed by altered expression of cytokines, including increased IL-33, and a dose-dependent elevation of CXCL1, CXCL5, and GCSF was observed in the lung tissue. In the bronchoalveolar lavage fluid of lewisite-exposed animals, there was a significant increase in HMGB1, a damage-associated molecular pattern molecule, as well as elevated CXCL1 and CXCL5, which coincided with an influx of neutrophils to the lungs. Complete blood cell analysis revealed eosinophilia and altered neutrophil-lymphocyte ratios as a consequence of lewisite exposure. Mean platelet volume and RBC distribution width, which are predictors of lung injury, were also increased in the lewisite group. These data demonstrate that cutaneous lewisite exposure causes ALI and may contribute to mortality in exposed populations.

The Correlation Between Asthma Severity and Neutrophil to Lymphocyte Ratio

Background—The prognosis is essential in management and follows up of asthmatic patients. Neutrophil to lymphocyte ratio is considered as the common prognostic marker for many diseases especially the asthma. Aim of study—To assess the relationship between asthma severity and neutrophil to lymphocyte ratio in comparison to healthy controls. Patients and methods—This study is a cross sectional study conducted in Respiratory Consultancy Clinic in Baghdad Teaching Hospital in Medical City during the period from 1st of October, 2018 to 31st of March, 2019 on sample of 50 asthmatic patients and 50 healthy controls. The diagnosis of asthma was confirmed by the supervisor through clinical symptoms, signs, spirometery with reversibility test (according to GINA guideline.). Results—A highly significant difference was observed between asthmatic cases and controls regarding age (p<0.001). A significant association was observed between obesity and asthmatic cases (p=0.001). There was a highly significant association between high neutrophil/lymphocyte ratio and asthmatic cases (p<0.001). The neutrophil/lymphocyte ratio was significantly increased with advanced age, females, severe and uncontrolled asthma. Conclusions—The neutrophil to lymphocyte ratio is useful biomarker in assessment of asthma severity.

ERS International Congress, Madrid, 2019: highlights from the Basic and Translational Science Assembly

In this review, the Basic and Translational Sciences Assembly of the European Respiratory Society (ERS) provides an overview of the 2019 ERS International Congress highlights. In particular, we discuss how the novel and very promising technology of single cell sequencing has led to the development of a comprehensive map of the human lung, the lung cell atlas, including the discovery of novel cell types and new insights into cellular trajectories in lung health and disease. Further, we summarise recent insights in the field of respiratory infections, which can aid in a better understanding of the molecular mechanisms underlying these infections in order to develop novel vaccines and improved treatment options. Novel concepts delineating the early origins of lung disease are focused on the effects of pre- and post-natal exposures on neonatal lung development and long-term lung health. Moreover, we discuss how these early life exposures can affect the lung microbiome and respiratory infections. In addition, the importance of metabolomics and mitochondrial function analysis to subphenotype chronic lung disease patients according to their metabolic program is described. Finally, basic and translational respiratory science is rapidly moving forward and this will be beneficial for an advanced molecular understanding of the mechanisms underlying a variety of lung diseases. In the long-term this will aid in the development of novel therapeutic targeting strategies in the field of respiratory medicine.

Highlights of basic and translational science presented at #ERSCongress 2019 summarising latest research on the lung cell atlas, lung infections, early origins of lung disease and the importance of metabolic alterations in the lunghttp://bit.ly/2UbdBs4

Hyperuricemia Is Not Predictive of Long-Term Outcome in Patients with Stable Chronic Obstructive Pulmonary Disease

BACKGROUND

Although the association of hyperuricemia with an increased risk of mortality has been demonstrated in the context of acute exacerbation of chronic obstructive pulmonary disease (COPD), the long-term outcomes of hyperuricemia have not been studied in the case of stable COPD.

METHODS

We retrospectively analyzed baseline data of 240 men with stable COPD enrolled in the Korea Obstructive Lung Disease cohort. We evaluated associations between serum uric acid levels and clinical parameters, risk factors for all-cause mortality, and acute exacerbation of COPD.

RESULTS

The mean age of subjects was 66.4 ± 7.7 years, and the median follow-up time was 5.9 years. We identified no significant difference in terms of lung function or laboratory findings between patients with hyperuricemia and those without. Serum uric acid level was negatively associated with systemic inflammation indicated by neutrophil-lymphocyte ratio (r = -0.211, P = 0.001). Univariate Cox regression analysis revealed hyperuricemia to not be associated with an increased risk of all-cause mortality in men with stable COPD (hazard ratio [HR], 0.580; 95% confidence interval [CI], 0.250-1.370; P = 0.213). In the multivariate Cox regression model, hyperuricemia was not an independent predictor of acute exacerbation (HR, 1.383; 95% CI, 0.977-1.959; P = 0.068).

CONCLUSION

Among men with stable COPD, hyperuricemia is not an independent predictor of all-cause mortality or future acute exacerbation of COPD. These results differ from those of previous studies on patients with acute exacerbation of COPD.

Feasibility of mean platelet volume as a biomarker for chronic obstructive pulmonary disease: A systematic review and meta-analysis

Objective

To evaluate the feasibility of mean platelet volume (MPV) as a biomarker for chronic obstructive pulmonary disease (COPD).

Methods

A systematic search for studies published up to March 2019 was performed in the PubMed and Web of Science databases. Three independent investigators screened the titles and abstracts of including studies according to eligibility criteria. The Newcastle–Ottawa Scale was used to assess the quality of eligible studies, and statistical analyses were performed using Review Manager version 5.3.

Results

A total of eight studies with 1230 COPD patients and 443 healthy controls were included in our meta-analysis. No significant differences in MPV level were identified in pairwise comparisons of the acute exacerbations of COPD (AECOPD), stable COPD, and control groups. Furthermore, no significant correlation was observed between MPV level and systemic inflammatory biomarkers.

Conclusions

MPV does not appear to represent a suitable biomarker of disease phase or inflammatory burden in COPD. However, future large-scale studies should be performed to further investigate the relationship between MPV and COPD.

Environmental correlates of chronic obstructive pulmonary disease in 96 779 participants from the UK Biobank: a cross-sectional, observational study

BACKGROUND

The role of environmental exposures in chronic obstructive pulmonary disease (COPD) remains inconclusive. We examined the association between environmental exposures (PM_2·5, greenness, and urbanicity) and COPD prevalence using the UK Biobank cohort data to identify key built environment correlates of COPD.

METHODS

In this cross-sectional, observational study we used baseline data for UK Biobank participants. Included participants were aged 39 years and older, white, had available spirometry data, and had complete data for phenotypes and exposures. COPD was defined by spirometry with the 2017 Global Initiative for Chronic Obstructive Lung Disease criteria. Environmental exposures were PM_2·5 derived from monitoring data and interpolated using land-use regression at the participants' geocoded residential addresses. Built environment metrics of residential greenness were modelled in terms of normalised difference vegetation index from remotely sensed colour infrared data within a 500 m residential catchment, and an urbanicity index derived from spatial analyses and measured with a 1 km buffer around each participant's residential address. Logistic regression models examined the associations between environmental exposures and COPD prevalence adjusting for a range of confounders. Subgroup analyses by urbanicity and effect modification by white blood cell count as an inflammatory marker were also done.

FINDINGS

We assessed 96 779 participants recruited between April 4, 2006, and Oct 1, 2010, of which 5391 participants had COPD with a prevalence of 5·6%. Each 10 μg/m³ increment in ambient PM_2·5 exposure at a participant's residential location was associated with higher odds of COPD (odds ratio 1·55, 95% CI 1·14-2·10). Among the built environment metrics, urbanicity was associated with higher odds of COPD (1·05, 1·01-1·08 per interquartile increment), whereas residential greenness was protective, being associated with lower odds of COPD (0·89, 0·84-0·93 for each interquartile increment in greenness). The results remained consistent in models of COPD defined as per lower limit of normal criteria. The highest quartile of white blood cell count was associated with lower lung function and higher COPD risk with a significant interaction between PM_2·5 and white blood cell count only in the model of lung function (p=0·0003).

INTERPRETATION

In this study of the built environment and COPD, to our knowledge the largest done in the UK, we found that exposure to ambient PM_2·5 and urbanicity were associated with a higher risk of COPD. Residing in greener areas, as measured by normalised difference vegetation index, was associated with lower odds of COPD, suggesting the potential value of urban planning and design in minimising or offsetting environmental risks for the prevention and management of COPD.

FUNDING

University of Hong Kong, UK Biobank, and UK Economic & Social Research Council.

Predictive Value of Novel Inflammation-Based Biomarkers for Pulmonary Hypertension in the Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Recently, there has been an increasing interest in the potential clinical use of several inflammatory indexes, namely, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic-immune-inflammation index (SII). This study aimed at assessing whether these markers could be early indicators of pulmonary hypertension (PH) in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). A total of 185 patients were enrolled in our retrospective study from January 2017 to January 2019. Receiver operating characteristic curve (ROC) and area under the curve (AUC) were used to evaluate the clinical significance of these biomarkers to predict PH in patients with AECOPD. According to the diagnostic criterion for PH by Doppler echocardiography, the patients were stratified into two groups. The study group consisted of 101 patients complicated with PH, and the control group had 84 patients. The NLR, PLR, and SII values of the PH group were significantly higher than those of the AECOPD one (p < 0.05). The blood biomarker levels were positively correlated with NT-proBNP levels, while they had no significant correlation with the estimated pulmonary arterial systolic pressure (PASP) other than PLR. NLR, PLR, and SII values were all associated with PH (p < 0.05) in the univariate analysis, but not in the multivariate analysis. The AUC of NLR used for predicting PH was 0.701 and was higher than PLR and SII. Using 4.659 as the cut-off value of NLR, the sensitivity was 81.2%, and the specificity was 59.5%. In conclusion, these simple markers may be useful in the prediction of PH in patients with AECOPD.