Neutrophil to lymphocyte ratio is a better indicator of COPD exacerbation severity in neutrophilic endotypes than eosinophilic endotypes

Short-term exposure to air pollution on peripheral white blood cells and inflammation biomarkers: a cross-sectional study on rural residents

Effects of short-term exposure to ambient air pollution on systemic immunological and inflammatory biomarkers in rural population have not been adequately characterized. From May to July 2021, 5816 participants in rural villages of northern Henan Province, China, participated in this cross-sectional study. Blood biomarkers of systemic inflammation were determined including peripheral white blood cells (WBC), eosinophils (EOS), basophils (BAS), monocytes (MON), lymphocytes (LYM), neutrophils (NEU), neutrophil-lymphocyte ratio (NLR), and serum high-sensitivity C-reactive protein (hs-CRP). The concentrations of ambient fine particulate matter (PM2.5), PM10, nitrogen dioxide (NO2), carbon monoxide (CO), and ozone (O3) were assessed up to 7 days prior to the blood draw. A generalized linear model was used to analyze the associations between air pollution exposure and the above-mentioned blood biomarkers. Significantly positive associations were revealed between PM2.5, CO and WBC; CO, O3 and LYM; PM2.5, PM10, SO2, CO and NEU; PM2.5, PM10, SO2, CO and NLR; PM2.5, PM10, SO2, NO2, CO, O3 and hs-CRP. Meanwhile, negative associations were found between SO2 and WBC; PM2.5, PM10, NO2, CO, or O3 and EOS; PM2.5, SO2, or CO and BAS; SO2, NO2 or O3 and MON; PM2.5, PM10, SO2, or NO2 and LYM. Moreover, men, individuals with normal body mass index (BMI), current smokers, and those older than 60 years were found vulnerable to air pollution effects. Taken together, short-term exposure to air pollution was associated with systemic inflammatory responses, providing insight into the potential mechanisms for air pollution-induced detrimental systemic effects in rural residents.

The association of systemic immune-inflammation index with lung function, risk of COPD and COPD severity: A population-based study

PURPOSE

The relationship between the levels of Systemic Immune-inflammation Index (SII) and chronic obstructive pulmonary disease (COPD), lung function, and COPD severity were not fully understood. We conducted this cross-sectional, population-based study to investigate the complex association between SII and COPD, lung function, and COPD severity among the US adults.

METHODS

Overall, 18,349 participants were included in the National Health and Nutrition Examination Survey (NHANES) between 2005 and 2018. The exposure variable was SII, calculated from platelet counts, neutrophil counts, and lymphocyte counts. Weighted univariable and multivariable logistic regression, subgroup analysis, and restricted cubic spline (RCS) regression were performed to assess the relationship between COPD, lung function, COPD severity and SII. Last, we used a propensity score matching (PSM) analysis to reduce selective bias and validate these relationships.

RESULTS

Approximately 1,094 (5.96%) of the participants were diagnosed as COPD. The multivariable-adjusted odds ratio (OR) (95% confidence interval, CI) for the Q2 group (Log-SII > 2.740) was 1.39 (1.16 to 1.68). Before and after matching, multivariable logistic regression models revealed that increased Log-SII levels (SII Logarithmic transformation) associated positively with the risk of COPD. The subgroup analysis showed no interaction between Log-SII and a variety of variables (P for interaction > 0.05). RCS showed a reversed L-shaped relationship between Log-SII with COPD (P for nonlinear = 0.001) in individuals. In addition, we observed negative significant correlations between forced expiratory volume in one second (FEV1) / forced vital capacity (FVC) %, FEV1/FVC% predicted and SII, and reversed U-shaped curve relationships between FEV1, FEV1% predicted and SII. High SII level is associated with severity of COPD, especially at Global Initiative on Obstructive Lung Disease (GOLD) 1 and GOLD 3.

CONCLUSIONS

In summary, the Log-SII level is associated with COPD risk, lung function, and COPD severity.

Meta-analysis of peripheral blood eosinophils in clinical testing of chronic obstructive pulmonary disease patients

Introduction

Meta-analysis was used to investigate the relationship between peripheral blood eosinophil (EOS) levels, clinical characteristics, and prognosis in chronic obstructive pulmonary disease (COPD)patients in previous literature.

Aim

To analyse the correlation between peripheral blood EOS levels and clinical characteristics and prognosis of patients with COPD using meta-analysis.

Material and methods

In databases such as PubMed, Embase, Web of Science, Cochrane Library, China National Knowledge Infrastructure (CNKI), and Wan Fang Data, literature related to the clinical characteristics or prognosis of COPD patients with high-level EOS published before July 2023 was searched for meta-analysis.

Results

Through computer search and screening, 29 articles were ultimately included. The meta-analysis results showed that compared to conventional EOS levels, COPD patients with high EOS levels had a lower proportion of GOLD III-IV grade patients (OR = 00.78, 95% CI (0.68, 0.88), p < 0.001), lower CAT scores (OR = -1.01, 95% CI (-1.75, -0.28), p = 0.007), shorter hospital stay (OR = -1.33, 95% CI (-1.52, -1.14), p < 0.001), and lower mortality rate (OR = 0.53, 95% CI (0.42, 0.66), p < 0.001). The readmission rate was low (OR = 0.40, 95% CI (0.33, 0.48), p < 0.001), and there was no statistically significant difference in FEV1%pred (OR = -0.55, 95% CI (-1.33, 0.23), p = 0.17), higher FEV1/FVC values (OR = -0.45, 95% CI (-1.08, 0.18), p = 0.160), and mechanical ventilation usage rate (OR = 0.89, 95% CI (0.65, 1.21), p = 0.450) among COPD patients with different EOS levels.

Conclusions

The levels of peripheral blood EOS in COPD patients are related to lung function, respiratory symptoms, etc.; Moreover, COPD patients with high-level EOS have shorter hospital stays, lower mortality and readmission rates. Therefore, ESO can be used as an auxiliary indicator for clinical symptom diagnosis of COPD patients and as an auxiliary indicator for predicting prognosis.

Neutrophil-to-Lymphocyte Ratio and Blood Eosinophil Levels As Inflammatory Indicators in Smoker and Non-smoker Young Adult Patients With Chronic Obstructive Pulmonary Disease at a Tertiary Care Hospital

Background Inflammatory markers are elevated in chronic obstructive pulmonary disease (COPD) and can be quantified to detect severity, prognosis, mortality risk, and response to treatment. However, the estimation costs are high. The blood neutrophil-to-lymphocyte ratio (NLR) and eosinophil levels are emerging as biomarkers in COPD, yet there is a paucity of data. Aim and objectives This study was designed to elucidate the roles of the NLR and eosinophil levels in smokers and non-smokers with stable COPD male subjects, correlating them with lung functions. Materials and methods A prospective observational clinical study was conducted from January to June 2023, after receiving approval from the Institutional Ethics Committee, on 73 COPD patients aged 30-60 years who gave voluntary informed consent. Complete blood counts and spirometry were performed. Patients with a forced expiratory volume in one second (FEV1) % predicted <70% and an FEV1/forced vital capacity (FVC) % <70% based on the pulmonary function test (MIR Spirolab) were included. They were further divided into mild (n=10), moderate (n=27), severe (n=26), and very severe (n=10) categories as per the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines. Subjects were also categorized into smoker (n=45) and non-smoker (n=28) groups. The complete blood count was analyzed using an automated analyzer (Beckman Coulter). Analysis was also carried out with an NLR of more or less than three. A P-value of less than 0.05 was considered significant. Results Smokers constituted 61.65% (n=45) of the subjects, and non-smokers 38.35% (n=28). Among smokers, 17.78% had very severe airflow obstruction. In all COPD subjects (n=73), lymphocytes, eosinophils, and lung functions were lower in the group where the NLR was greater than three. NLR in smokers (3.52±1.43) was higher than in non-smokers (3.39±0.94). In non-smokers (n=28), blood eosinophils and lymphocytes were elevated. In smokers (n=45), blood neutrophils, monocytes, and basophils were increased. Smokers showed a non-significant increase in RBC, mean corpuscular volume (MCV), and mean corpuscular hemoglobin (MCH). Neutrophils, monocytes, eosinophils, and NLR increased with disease severity. NLR negatively correlated with FEV1 (r=-0.350, p=0.034) and positively with pack-years (r=0.546, p<0.001) in smokers. NLR negatively correlated with eosinophils, FVC, FEV1/FVC, and FEV1 % predicted. In all COPD subjects (n=73), NLR negatively correlated with blood eosinophils (r=-0.184, p=0.12), BMI, and lung functions. Conclusion NLR is elevated in COPD subjects and can serve as a marker of inflammation and a predictor of the risk and severity of airflow limitation. NLR correlates both positively and negatively with pack-years and lung functions, respectively.

Predictive Role of White Blood Cell Differential Count for the Development of Acute Exacerbation in Korean Chronic Obstructive Pulmonary Disease

Purpose

Chronic obstructive pulmonary disease (COPD) is a respiratory disease characterized by chronic inflammation. Acute exacerbation of COPD (AECOPD) manifests as acute worsening of respiratory symptoms and is associated with high morbidity and mortality. The aim of the present study was to evaluate the predictive value of white blood count (WBC) and its derived inflammatory biomarkers for AECOPD.

Methods

From the Korean COPD Subgroup Study cohort, a prospective and multicenter observational study, 826 patients who had baseline complete blood count (CBC) and 3-year AECOPD data were included. Follow-up CBC data at 1 (n = 385), 2 (n = 294), and 3 (n = 231) years were collected for available patients. The primary outcome was the occurrence of AECOPD at 3 years. The risk of AECOPD was evaluated using a binary logistic analysis.

Results

The cumulative incidences of 12-, 24-, and 36-month AECOPD were 47.6%, 60.5%, and 67.6%, respectively. Patients with AECOPD at 3 years had higher baseline WBC counts, neutrophil counts, neutrophil/lymphocyte ratio (NLR), and neutrophil/monocyte ratio than those without AECOPD. Higher WBC count, neutrophil count, and NLR were associated with the 3-year occurrence of AECOPD in the univariate analysis, but only the higher neutrophil count was a significant risk factor (odds ratio [OR] = 1.468; 95% confidence interval [CI]: 1.024-2.104) in the covariates-adjusted analysis. In the analysis of changes in inflammatory parameters, a decrease in the platelet count (OR = 0.502; 95% CI: 0.280-0.902) and NLR (OR = 0.535; 95% CI: 0.294-0.974) at 2 years and an increase in the eosinophil count (OR = 2.130; 95% CI: 1.027-4.416) at 3 years were significantly associated with AECOPD in the adjusted analysis.

Conclusion

Our data suggest that a high baseline WBC count, particularly neutrophil count, was associated with a higher incidence of long-term AECOPD.

Prediction value of neutrophil and eosinophil count at risk of COPD exacerbation

INTRODUCTION

Predicting acute exacerbations (AEs) in chronic obstructive pulmonary disease (COPD) is crucial. This study aimed to identify blood biomarkers for predicting COPD exacerbations by inflammatory phenotypes.

MATERIALS AND METHODS

We analyzed blood cell counts and clinical outcomes in 340 COPD patients aged 20-90 years. Patients were categorized into eosinophilic inflammation (EOCOPD) and non-eosinophilic inflammation (N-EOCOPD) groups. Blood cell counts, eosinophil-to-lymphocyte ratio (ELR), neutrophil-to-lymphocyte ratio (NLR) and neutrophil-to-eosinophil ratio (NER) were calculated. Linear and logistic regression models assessed relationships between health outcomes and blood cell counts.

RESULTS

EOCOPD patients had distinct characteristics compared to N-EOCOPD patients. Increased neutrophil % and decreased lymphocyte % were associated with reduced pulmonary function, worse quality of life and more exacerbations, but they did not show statistical significance after adjusting by age, sex, BMI, smoking status, FEV1% and patient's medication. Subgroup analysis revealed a 1.372-fold increase in the OR of AE for every 1 unit increase in NLR in EOCOPD patients (p < .05). In N-EOCOPD patients, every 1% increase in blood eosinophil decreased the risk of exacerbation by 59.6%.

CONCLUSIONS

Our study indicates that distinct white blood cell profiles in COPD patients, with or without eosinophilic inflammation, can help assess the risk of AE in clinical settings.

Monocyte related haematological indices in acute exacerbations of COPD - a new biomarker?

C-reactive protein (CRP) and leukocyte count are standard tools for recognising inflammation in COPD patients. This study aimed to find if there is a pattern in monocyte related haematological indices - monocyte to neutrophil ratio (MNR) and monocyte to lymphocyte ratio (MLR) - which could be helpful in differentiating COPD patients in need for hospitalization due to acute exacerbation of COPD or differentiating frequent COPD exacerbators from non-frequent COPD exacerbators. The study included 119 patients with COPD and 35 control subjects, recruited at the Clinic for Respiratory Diseases Jordanovac, University Hospital Centre Zagreb, Croatia. Complete blood count was performed on Sysmex XN-1000, CRP on Cobas c501, and Fbg on BCS XP analyser. Data were analysed with MedCalc statistical software. The COPD patients were divided into three groups - frequent exacerbators (FE), non-frequent exacerbators (NFE), patients hospitalized for acute COPD exacerbations (HAE) and the control group were healthy smokers (HS). A statistically significant difference was found in the values of MNR while comparing these groups of patients: FE vs HAE (p<0.000), NFE vs HAE (p<0.000) and HS vs HAE (p<0.001); and for the values of MLR: FE vs HAE (p<0.022), NFE vs HAE (p<0.000) and HS vs HAE (p<0.000). As MLR and MNR have shown the statistical difference comparing the group of HAE to NFE, FE and HS, MLR and MNR could be valuable and available markers of acute COPD exacerbations and need for hospitalization.

Serum YKL-40 Levels, Leukocyte Profiles, and Acute Exacerbations of Advanced COPD

Little information exists on YKL-40-a key protein in tissue remodeling-and complete blood count (CBC) parameters during acute exacerbations of advanced chronic obstructive pulmonary disease (COPD). This pilot exploratory study (August 2020-January 2021) investigated the connection between serum YKL-40 levels and CBC profile in sex- and age-matched individuals with severe COPD (GOLD stage III, n = 23, median age = 66 years, 65.21% males) and very severe COPD (GOLD stage IV, n = 24, median age = 66.5 years, 74.81% males). The measured parameters were serum YKL-40, absolute leukocyte count (ALLC), absolute neutrophil count (ANC), neutrophil percentage, absolute lymphocyte count (ALC), lymphocyte percentage, neutrophil-to-lymphocyte ratio (NLR), absolute eosinophil count (AEC), eosinophil percentage, absolute monocyte count (AMC), monocyte percentage, absolute basophil count (ABC), basophil percentage, hemoglobin levels, and hematocrit concentrations. No significant inter-group differences were observed. However, high YKL-40 subjects (n = 23)-as stratified via median YKL-40 (3934.5 pg/mL)-showed significantly increased neutrophil percentage and NLR but significantly lower lymphocyte-, eosinophil-, and basophil-related parameters compared to low YKL-40 patients (n = 24). These results reveal multidimensional, YKL-40-associated changes in leukocyte profile of patients with advanced COPD during acute exacerbations, with potential implications for personalized treatment.

Short-term impacts of air pollution on the platelet-lymphocyte ratio and neutrophil-lymphocyte ratio among urban adults in China

The short-term impacts of urban air pollution on the platelet-lymphocyte ratio (PLR) and neutrophil-lymphocyte ratio (NLR) remain obscure. In this study, we included 3487 urban adults from the Wuhan-Zhuhai cohort. Individual inhalation exposure to air pollutants was estimated by combining participants' daily breath volume and ambient concentrations of six air pollutants (including fine particulate matter (PM_2.5), inhalable particulate matter (PM₁₀), nitrogen dioxide (NO₂), sulfur dioxide (SO₂), carbon monoxide (CO) and ozone (O₃)). The cumulative impacts were assessed by applying lag structures of up to 7 days before the survey date. Associations of air pollutants with PLR and NLR were assessed using a linear mixed model and Bayesian kernel machine regression (BKMR) model. We found that PLR was negatively related to PM_2.5 (lag02-lag06), PM₁₀ (lag02-lag07), NO₂ (lag02-lag07), and SO₂ (lag03-lag05) and NLR was negatively related to PM₁₀ (lag05 and lag07). In the BKMR model, a negative joint association between the six-air-pollutant mixture and PLR and NLR was observed, whereas PM₁₀ and NO₂ appeared to be more important than the other pollutants in the mixture. The negative impact of air pollutants was stronger in males, participants with lower body mass index (< 24 kg/m²), those cooking meals at home, drinkers, and non-exercisers. In conclusion, short-term exposure to air pollutants is significantly related to PLR and NLR in peripheral blood. PLR and NLR may provide new insight into the molecular mechanism underlying the adverse health impact of air pollutants.

Blood monocyte levels predict the risk of acute exacerbations of chronic obstructive pulmonary disease: a retrospective case-control study

Monocytes were critical cells in the innate immune system. Monocyte recruitment to the lungs is a crucial process of pathophysiology in chronic obstructive pulmonary disease (COPD). Current evidence on the association between the occurrence of acute exacerbations of COPD (AECOPD) and monocytes was unclear. This study aimed to examine whether blood monocytes are associated with the occurrence of AECOPD and to determine the specific blood monocyte level to predict AECOPD. A retrospective case-control study was conducted at Changhua Christian Hospital. A total of 444 eligible patients with COPD were included between January 2017 and December 2019. Restricted cubic splines were used to analyze the nonlinear relationships between continuous white blood cell values and the occurrence of AECOPD. The association between monocytes and the occurrence of AECOPD was assessed using the logistic, lasso, and ridge regression models. Restricted cubic splines revealed nonlinear associations among the monocyte level, the continuous value of the eosinophil-to-lymphocyte ratio, and the occurrence of AECOPD. The lowest risk of occurrence of AECOPD ranged from 7.4 to 10%; < 7.4% with an absolute count < 0.62 or > 10% indicated significant risk. No significant association was noted between the eosinophil-to-lymphocyte ratio categories in the tertiles (< 0.049, 0.049 to < 0.122, and ≥ 0.122) and the risk of AECOPD. A significantly higher risk was noted in the association of the occurrence of AECOPD with the CAT score; mMRC score; wheezing cough; preexisting chronic pulmonary disease; hypertension and malignancy; use of dual- and triple, and oral long-acting bronchodilators for COPD treatment; and WBC count. We reported a nonlinear relationship between monocytes and the occurrence of AECOPD. Patients with monocyte percentage of > 10% or < 7.4% with an absolute count < 0.62 had higher risk of occurrence of AECOPD. Overall, our study demonstrated the specific value of monocytes in identifying high risks of the occurrence of AECOPD; this value is an easy-to-obtain, inexpensive biomarker in patients with AECOPD and should be further investigated in future prospective clinical studies.

Risk Factors for Length of Hospital Stay in Acute Exacerbation Chronic Obstructive Pulmonary Disease: A Multicenter Cross-Sectional Study

Background/Purpose

Patients and Methods

Results

Conclusion

Association of baseline parameters with year 0 and year 1 acute exacerbations in male patients with chronic obstructive pulmonary disease

Objectives

Acute exacerbations (AEs) of chronic obstructive pulmonary disease (COPD) can affect health status, hospitalization and readmission rates, and disease progression. This study aimed to identify independent markers associated with COPD AEs.

Methods

This study included male patients with COPD and collected data regarding their AEs and baseline clinical parameters.

Results

We included 149 male patients. Among them, 58 were included in the year 0 high-AE group and 91 in the low-AE group. Multivariate analysis revealed that the high-AE group had higher white blood cell count, lower serum albumin level, and post-bronchodilator (BD) forced expiratory volume in one second (FEV₁) (%) with a combined receiver operating characteristic curve (ROC) of 0.721 (p < 0.001). Additionally, 34 patients were included in the year 1 high-AE group and 70 in the low-AE group (p < 0.001). Multivariate analysis revealed that the high-AE group had higher platelet count, positive asthma history, and lower pre-BD FEV₁ (%) with a combined ROC of 0.782 (p < 0.001).

Conclusion

In male patients with COPD, baseline white blood cell count, albumin level, and post-BD FEV₁ (%) were correlated with year 0 AE; on the other hand, baseline platelet count, positive asthma history, and pre-BD FEV₁ (%) were associated with year 1 AE.

Role of Systemic Inflammatory Reaction in Female Genital Organ Malignancies - State of the Art

Systemic inflammatory reaction (SIR) is an unfavorable prognostic factor in many malignancies and has a role in all stages of the neoplastic process: initiation, promotion, and disease progression. Analysis of SIR can be performed by assessing indicators (eg, lymphocyte-to-neutrophil, platelet-to-lymphocyte, and monocyte-to-neutrophil ratios) and products of neutrophils and lymphocytes (ie, the systemic immune-inflammation index), or by examining the relationship between levels of C-reactive protein and albumin (based on the Glasgow Prognostic Score, modified Glasgow Prognostic Score, and C-reactive protein-to-albumin ratio). Risk stratification is essential in the clinical management of cancer; hence, the evaluation of these factors has potential applications in the clinical management of patients with cancer and in the development of new therapeutic targets. This review summarizes the current knowledge on SIR indicators and presents their clinical utility in malignancies of the female genital organs.

Blood eosinophil count-guided corticosteroid therapy and as a prognostic biomarker of exacerbations of chronic obstructive pulmonary disease: a systematic review and meta-analysis

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is characterized by persistent respiratory symptoms and dyspnea, as well as an increase in the number of leukocytes in the airways, lungs, and pulmonary vessels. A 'One size fits all' approach to COPD patients with different clinical features may be considered outdated. The following are the two major objectives of this meta-analysis: the first is to determine if blood eosinophil counts (BEC) can serve as a prognostic biomarker of COPD outcomes, and the second is to determine which level of BEC is effective for inhaled corticosteroid (ICS) treatment.

METHODS

We searched articles published before 15 May 2021 in the following four electronic databases: Web of Science, Cochrane Library, EMBASE, and PubMed.

RESULTS

A total of 42 studies, comprising a sampling of 188,710 subjects, were summarized and compared in this meta-analysis. The rate ratio (RR) of exacerbations of COPD (ECOPD) between ICS and non-ICS treatment was statistically significant for the COPD patients with a baseline BEC ⩾ 2% or ⩾ 200 cells/μl, RR = 0.82 (0.73, 0.93) or 0.79 (0.70, 0.89) respectively, while the RR of ECOPD between ICS and non-ICS treatment was statistically insignificant for the COPD patients with baseline BEC < 2% or <200 cells/μl, RR = 0.97 (0.87, 1.08) or 0.97 (0.86, 1.08), suggested that ICS therapy was beneficial to the improvement of ECOPD in patients with a baseline BEC ⩾ 2% or BEC ⩾ 200 cells/μl.

CONCLUSION

Our research shows that a BEC ⩾ 200 cells/μl or ⩾2% is likely to become the cutoff value of ICS treatment for ECOPD. Moreover, we believe that the baseline BEC can be used as a biomarker for predicting ECOPD. The stability of BEC requires special attention.

The correlational study about neutrophil-to-lymphocyte ratio and exercise tolerance of chronic obstructive pulmonary disease patients

To study the relationship between neutrophil to lymphocyte ratio (NLR) and exercise tolerance of patients with chronic obstructive pulmonary disease (COPD).235 patients with COPD were selected as the study subjects. Complete blood count, C reactive protein (CRP), pulmonary function tests, the 6-minute walk distance (6MWD), Modified Medical Respiratory Council, the COPD assessment test, and clinical COPD questionnaire were tested. Heart rate, oxygen saturation, and Borg scale were tested before or after 6MWD test.By the median of NLR, the subjects were divided into 2 groups, NLR ≥4.5 group and NLR <4.5 group. The white blood cell count (WBC), CRP and deoxygenation saturation in the NLR ≥4.5 group were higher than those in the NLR <4.5 group, while the age, body mass index (BMI), 6MWD, and heart rate variation were lower than those in the NLR <4.5 group. CRP, WBC, and deoxygenation saturation had positive effects on NLR, BMI, 6MWT, and heart rate variation had negative effects on NLR. The Pearson correlation analysis showed NLR was positively correlated with WBC, CRP, BMI index, 6MWT, and deoxygenation saturation, while it was negatively correlated with BMI and heart rate variation.NLR might associate with exercise tolerance and cardiorespiratory reserve of COPD patients, and could be used as an indicator of muscle function in COPD patients.

Endo-phenotyping of COPD patients

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is a heterogeneous syndrome and may comprise several different phenotypes that are driven by different molecular mechanisms (endotypes). Several different clinical, genetic, and inflammatory phenotypes of COPD have been recognized and this may lead to more precise effective therapies.

AREAS COVERED

The different clinical phenotypes, including smoking versus nonsmoking COPD, small airway disease versus emphysema, non-exacerbators versus frequent exacerbators are discussed. Rare genetic endotypes (alpha₁-antitrypsin deficiency, telomerase polymorphisms), and inflammatory phenotypes (eosinophilic versus neutrophilic) are also recognized in stable and exacerbating patients and have implications for the choice of therapy.

EXPERT OPINION

Clinical phenotypes have so far not proved to be very useful in selecting more personalized therapy for COPD. Even with genetic endotypes, this has not led to improved therapy. More promising is the recognition that COPD patients who have increased sputum or blood eosinophils tend to have more frequent exacerbations and inhaled corticosteroids are more effective in preventing exacerbation. Increased blood eosinophils have proved to be a useful biomarker now used to target ICS more effectively. Furthermore, COPD patients with low eosinophils are more likely to get pneumonia with ICS and to have lower airway bacterial colonization.

Analysis of Blood Biomarkers in Patients with Chronic Obstructive Pulmonary Disease (COPD) and with Asthma-COPD Overlap (ACO)

Chronic obstructive pulmonary disease (COPD) is a heterogeneous entity with different clinical phenotypes, such as asthma-COPD overlap (ACO). The aim of this retrospective study was to compare routine blood biomarkers in patients with ACO and the remaning COPD phenotypes. Data were collected from stable COPD patients visited in during 2018, including C-reactive protein (CRP), fibrinogen, neutrophyl/lymphocyte ratio (NLR) and platelet/lymphocyte ratio (PLR).A total of 77 patients with COPD were included, 24 (31%) fulfilled the diagnosis of ACO. Clinically, patients with ACO presented more dyspnoea and wheezing. Regarding laboratory parameters, both groups had low levels of lymphocytes, especially the non-ACO group (24.2% vs. 29.3%; p = 0.031), patients with ACO had significantly higher eosinophil counts (4.7% vs. 1.9%; p < 0.001) but a lower percentage of neutrophils (56.8% vs. 64.7%; p = 0.003), NLR and PLR (2.5 vs. 3.8; p = 0.013 and 115 vs. 160; p = 0.063, respectively). In conclusion, besides the expected eosinophilic inflammation in patients with ACO, both groups had low levels of lymphocytes, especially the non-ACO group. The low levels of lymphocytes, in particular in non-ACO patients, should be confirmed in larger studies.

Correlations between neutrophil to lymphocyte ratio, blood eosinophils and clinical characteristics in chronic obstructive pulmonary disease

BACKGROUND AND AIMS

Chronic obstructive pulmonary disease (COPD) is currently the third leading cause of death worldwide, with increasing mortality and morbidity. The neutrophil to lymphocyte ratio (NLR) and blood eosinophils level (EOS) represent biomarkers of inflammation in various diseases, with current research in the field of COPD. The aim of this study was to determine correlations of NLR and EOS with certain characteristics of COPD in a group of patients without major comorbidities.

METHODS

We conducted an observational study on COPD patients admitted to the Clinical Hospital of Pneumology in Cluj-Napoca, Romania. The smoking history, body mass index (BMI), NLR, EOS, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and the arterial partial pressure of oxygen (PaO2) were determined. Functional assessment consisted of spirometric and BODE index determinations. The duration of hospitalization was expressed as the length of stay (LOS). The patients were divided into 3 subgroups: active smokers (AS), former smokers (FS) and never smokers (NS).

RESULTS

No significant differences between AS and FS were found when age, airway obstruction, BODE index, PaO2, ESR and CRP were considered. The NLR was higher in AS versus FS (p=0.035), while EOS was lower in AS group (p=0.061). COPD patients with ≥300 EOS/μL had lower CRP, ESR levels and NLR compared to those with eosinophilia <300/μL (p=0.020, p=0.009 and p=0.007, respectively). With a threshold of 3.5 for NLR, patients with lower NLR had lower CRP values (p=0.05). COPD patients with higher NLR had significant lower EOS levels (p=0.018). Overall, the NLR and EOS were not correlated with the investigated characteristics (p>0.05), but intragroup analysis (based on smoking status) revealed correlations with ESR (p=0.0001), CRP (p=0.053), BODE index (p=0.029) and LOS (p=0.042).

CONCLUSIONS

AS have higher NLR and lower EOS levels versus FS. COPD patients with higher EOS level have lower CRP, ESR and NLR. In AS, EOS level is positively correlated with BODE index and negatively correlated with NLR.

Association Between Routine Blood Biomarkers and Clinical Phenotypes and Exacerbations in Chronic Obstructive Pulmonary Disease

Introduction

Chronic obstructive pulmonary disease (COPD) is associated with increased lung and systemic inflammation. We aimed to identify associations between easy-to-obtain blood biomarkers and the frequency and severity of exacerbations.

Methods

Cross-sectional, multicentre study performed in four centres in Spain, Italy, Bulgaria, and Slovenia. Blood samples were obtained for blood cell count, C-reactive protein (CRP), alpha-1 antitrypsin (AAT) and fibrinogen analysis. The neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR) and eosinophil/basophil ratio (EBR) were calculated. Firstly, patients were divided into clinical phenotypes according to the Spanish guidelines of COPD, and secondly, patients were classified into 2 groups: non-exacerbators (≤1 ambulatory exacerbation in the previous year) and exacerbators (≥2 ambulatory exacerbations or 1 hospitalisation in the previous year). A multivariate stepwise logistic regression model was performed to identify laboratory parameters associated with exacerbators.

Results

A total of 355 patients with a mean age 66 years (SD=8.9) were included, and 64% were male. The mean FEV1% (forced expiratory volume in the first second) was 55% (SD=20%), and the mean COPD Assessment Test (CAT) score was 15.6 (SD=7.9). One hundred ninety-six (55.2%) patients were classified in the non-exacerbator group, and 159 (44.8%) were exacerbators. Patients in the exacerbators group presented lower haemoglobin levels (p=0.019) and ERB (p= 0.023) but higher CRP levels (p=0.001). In the multivariate analysis, females, higher levels of CRP, lower FEV1% and low EBR were independently related to exacerbators.

Conclusion

Female sex, having a more severe impairment of lung function, higher CRP levels and a lower EBR are associated with an exacerbator phenotype in COPD.

Prognostic value of platelet and neutrophil to lymphocyte ratio in COPD patients

Background: Chronic obstructive pulmonary disease (COPD) is the third driving reason for death around the world and a real number of patients suffers from disease exacerbation. Platelet lymphocyte ratio (PLR) and neutrophil lymphocyte ratio (NLR) are novel biomarkers in acute exacerbation of COPD (AECOPD) and related to expanded 90-day mortality in patients with COPD.Objectives: This work aimed to assess NLR and PLR in COPD patients.Methods: This case-control study was carried out on 100 COPD patients and 60 healthy subjects. Complete blood count (CBC) with differential was made during and after exacerbation to define NLR and PLR.Results: The cases and controls groups were matched as regards age, sex, and body mass index (BMI) (P-values: 0.3, 0.2, and 0.06 respectively). NLR and PLR were increased significantly in COPD patients (2.24 ± 0.56 and 157.1 ± 28.36) compared to control group (1.31 ± 0.23 and 102.82 ± 3.99) (P-value < 0.0001). During exacerbation NLR and PLR were elevated significantly compared to stable condition (P-value < 0.0001). NLR and PLR show a significant positive correlation with smoking index, COPD stage, and dyspnea severity.Conclusion: NLR and PLR increased in stable COPD patients and further increased during exacerbation that can predict in hospital mortality.

Inflammatory endotypes in COPD

Chronic obstructive pulmonary disease (COPD) is a major global health problem that is poorly treated by current therapies as it has proved difficult to treat the underlying inflammation, which is largely corticosteroid-resistant in most patients. Although rare genetic endotypes of COPD have been recognized, despite the clinical heterogeneity of COPD, it has proved difficult to identify distinct inflammatory endotypes. Most patients have increased neutrophils and macrophages in sputum, reflecting the increased secretion of neutrophil and monocyte chemotactic mediators in the lungs. However, some patients also have increased eosinophils in sputum and this may be reflected by increased blood eosinophils. Increased blood and sputum eosinophils are associated with more frequent exacerbations and predict a good response to corticosteroids in reducing and treating acute exacerbations. Eosinophilic COPD may represent an overlap with asthma but the mechanism of eosinophilia is uncertain as, although an increase in sputum IL-5 has been detected, anti-IL-5 therapies are not effective in preventing exacerbations. More research is needed to link inflammatory endotypes to clinical manifestations and outcomes in COPD and in particular to predict response to precision medicines.