Pharmacological treatment of stable chronic obstructive pulmonary disease

Protective Effect of the Total Alkaloid Extract from Bulbus Fritillariae pallidiflorae in a Mouse Model of Cigarette Smoke-Induced Chronic Obstructive Pulmonary Disease

Purpose

In recent years, the incidence of chronic obstructive pulmonary disease (COPD) has been increasing year by year, but therapeutic drugs has no breakthrough. The total alkaloid extract from Bulbus Fritillariae pallidiflorae (BFP-TA) is widely used in treating lung diseases. Therefore, this study aimed to investigate the protective effect and mechanism of BFP-TA in COPD mice.

Methods

BFP-TA was prepared by macroporous adsorbent resin, and the material basis of BFP-TA was analyzed by HPLC-ELSD and UHPLC-MS/MS. Then, the COPD mouse model was induced by cigarette smoke (CS) for 12 weeks, administered at weeks 9-12. Subsequently, the body weight, lung-body ratio, pulmonary function, histopathology, and the levels of pro-inflammatory cytokines, matrix metalloproteinases (MMPs) and oxidative stress markers in the serum of mice were determined. The expressions of related protein of EMT and MAPK signaling pathways in the lung tissues of mice were detected by Western blot.

Results

The alkaloid relative content of BFP-TA is 64.28%, and nine alkaloids in BFP-TA were identified and quantified by UHPLC-MS/MS. Subsequently, the animal experiment showed that BFP-TA could improve pulmonary function, and alleviate inflammatory cell infiltration, pulmonary emphysema, and collagen fiber deposition in the lung of COPD mice. Furthermore, BFP-TA could decrease the levels of pro-inflammatory cytokines (TNF-α, IL-6 and IL-1β), MMPs (MMP-9 and MMP-12) and MDA, while increase the levels of TIMP-1 and SOD. Moreover, BFP-TA could decrease the protein expressions of collagen I, vimentin, α-SMA, MMP-9, MMP-9/TIMP-1, Bax, p-JNK/JNK, p-P38/P38, and p-ERK/ERK, while increase the level of E-cadherin.

Conclusion

This study is the first to demonstrate the protective effect of BFP-TA in CS-induced COPD mouse model. Furthermore, BFP-TA may improve airway remodeling by inhibiting the EMT process and potentially exert anti-inflammatory effect by inhibiting the MAPK signaling pathway.

The Bufei Nashen pill inhibits the PI3K/AKT/HIF-1 signaling pathway to regulate extracellular matrix deposition and improve COPD progression

ETHNOPHARMACOLOGICAL RELEVANCE

According to the theory and practice of traditional Chinese medicine (TCM), chronic obstructive pulmonary disease (COPD) can be classified as "cough," "dyspnea," or "lung distention disease." Bufei Nashen pill (BFNSP) is a classic Chinese herbal formula with certain activity against the above syndromes. FNSP has previously been shown to improve clinical symptoms (cough, lumbar and knee weakness, tinnitus) in patients with occupationally related interstitial lung disease.

AIM OF THE STUDY

There is a lack of convincing evidence supporting the use of BFNSP for the treatment of COPD. This study aimed to investigate the effect of BFNSP on COPD and explore its underlying mechanisms.

MATERIALS AND METHODS

Liquid chromatography-mass spectrometry (LC/MS) was used to analyze the main components of BFNSP and BFNSP-containing serum. A COPD rat model was generated, and the rats were treated with different doses of BFNSP. Lung function indices were analyzed by a pulmonary function testing system, and lung histopathology was assessed by HE staining and scanning electron microscopy. The levels of TGF-β1, IL-6, IL-8, IL-1β, MMP3, MMP-9, and TIMP1 in BALF and the levels of MMP3, MMP-9, TIMP1, and HA in serum were detected by ELISA. Immunohistochemical staining was performed to determine the expression of Col-I, Col-III, and LN in lung tissues. RT‒qPCR was performed to detect the mRNA expression of PI3K, Akt, HIF-1α, MMP-9, TGF-β1, TIMP1, and ERK1/2 in lung tissue, and Western blotting was performed to detect the protein expression of PI3K, p-PI3K, Akt, p-Akt, HIF-1α, MMP-9, TGF-β1, TIMP1, and p-ERK1/2 in lung tissue. In addition, in vitro cellular assays were performed for validation.

RESULTS

The results showed that BFNSP effectively improved the functional status of pulmonary ventilation, attenuated pathological damage in lung tissue, inhibited the release of inflammatory factors, reduced extracellular matrix deposition, and inhibited the activation of the PI3K/AKT/HIF-1 signaling pathway in lung tissue in COPD rats (P<0.05) and may alleviate COPD progression by inhibiting the PI3K/AKT/HIF-1 signaling pathway.

CONCLUSION

BFNSP inhibits the PI3K/AKT/HIF-1 signaling pathway to regulate extracellular matrix deposition and improve COPD progression.

The cuproptosis-related gene glutaminase promotes alveolar macrophage copper ion accumulation in chronic obstructive pulmonary disease

Cuproptosis, a novel mode of cell death, is strongly associated with a variety of diseases. However, the contribution of cuproptosis to the onset or progression of chronic obstructive pulmonary disease (COPD), the third most common chronic cause of mortality, is not yet clear. To investigate the potential role of cuproptosis in COPD, raw datasets from multiple public clinical COPD databases (including RNA-seq, phenotype, and lung function data) were used. For further validation, mice exposed to cigarette smoke for three months were used as in vivo models, and iBMDMs (immortalized bone marrow-derived macrophages) and RAW264.7 cells stimulated with cigarette smoke extract were used as in vitro models. For the first time, the expression of the cuproptosis-related gene glutaminase (GLS) was found to be decreased in COPD, and the low expression of GLS was significantly associated with the grade of pulmonary function. In vivo experiments confirmed the decreased expression of GLS in COPD, particularly in alveolar macrophages. Furthermore, in vitro studies revealed that copper ions accumulated in alveolar macrophages, leading to a substantially decreased amount of cell activity of macrophages when stimulated with cigarette extract. In summary, we demonstrate the high potential of GLS as an avenue for diagnosis and therapy in COPD.

Knockdown of JMJD3 ameliorates cigarette smoke extract-triggered bronchial epithelial cell injury via ACSL4-dependent ferroptosis

Chronic obstructive pulmonary disease (COPD), a heterogeneity of chronic respiratory disease pattern, presents considerable prevalence and mortality. We aimed to explore the role and mechanisms of Jumonji domain-containing protein-3 (JMJD3) in COPD. The viability and JMJD3 expression in human bronchial epithelial cell line BEAS-2B were respectively assayed by CCK-8 assay and Western blot following stepwise exposure to increasing concentrations of cigarette smoke extract (CSE). After JMJD3 was silenced and acyl-CoA synthetase long-chain family member 4 (ACSL4) was overexpressed in CSE-treated BEAS-2B cells, cell viability, cytotoxicity, oxidative stress and total iron level were estimated using kits. ELISA estimated inflammatory levels. DCFH-DA probe and BODIPY 581/591 C11 probe were exposed to assess ROS production and lipid peroxidation. Western blot tested the expressions of ferroptosis-associated proteins. Besides, H3K27me3 and ACSL4 expressions were tested by Western blot and immunofluorescence staining. In CSE-induced BEAS-2B cells, JMJD3 expression was increased and deletion of JMJD3 improved cell viability, reduced LDH release, mitigated inflammation, oxidative stress and inhibited ferroptosis. Moreover, JMJD3 interference raised H3K27me3 expression whereas lessened ACSL4 expression in CSE-treated BEAS-2B cells. CSE exposure reduced the abundance of ACSL4 in H3K27me3 antibody. Further ACSL4 elevation reversed the impacts of JMJD3 silencing on the damage of CSE-induced BEAS-2B cells. Collectively, JMJD3 depletion might suppress ferroptosis mediated by ACSL4 to alleviate CSE-triggered inflammation and oxidative stress in BEAS-2B cells.

Network pharmacology prediction and molecular docking analysis reveal the mechanism of modified Bushen Yiqi formulas on chronic obstructive pulmonary disease

BACKGROUND

The present study aimed to explore the mechanism of the modified Bushen Yiqi formula (MBYF) in the treatment of chronic obstructive pulmonary disease (COPD) based on network pharmacology and molecular docking.

METHODS

First, the active ingredients and corresponding targets in MBYF were mined through the Traditional Chinese Medicine Systems Pharmacology database. Subsequently, Online Mendelian Inheritance in Man, DrugBank, and GeneCard were used to screen COPD-related targets. Cytoscape was used to construct a network of candidate components of MBYF in COPD treatment. The overlapping targets of COPD and MBYF were used to treat COPD, and then CytoHubba and CytoNAC plug-ins in Cytoscape were used for topology analysis to build the core network. In addition, core targets were used for Gene Ontology analysis and enrichment analysis of the Kyoto Encyclopedia of Genes and Genomes. Finally, AutoDock Vina software was used to conduct a molecular docking study on the core active ingredients and core targets to verify the above network pharmacological analysis.

RESULTS

Seventy-nine active components of MBYF were screened and 261 corresponding targets were found. At the same time, 1307 related targets corresponding to COPD were screened and 111 overlapping targets were matched. By bioinformatics analysis, 10 core targets were identified, and subsequently, enrichment analysis revealed 385 BP, two CC, eight MF and 78 related signaling pathways. The binding of the core active components in MBYF to the core target was further verified by molecular docking, and all showed good binding.

CONCLUSIONS

The active components of MBYF, such as quercetin, kaempferol, luteolin, and baicalein, may be the material basis for the treatment of chronic obstructive pulmonary disease. They affect the expression of inflammatory cells and inflammatory factors, protein phosphorylation, and smooth muscle hyperplasia through tumor necrosis factor, interleukin-17, mitogen-activated protein kinase, nuclear factor-kappa B and other signaling pathways.

The Study of the Influence of IL5RA Variants on Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a complex disease, and its pathogenesis is influenced by genetic factors. This study aimed to evaluate the role of IL5RA genetic variation in the risk of COPD. In this study, 498 patients with COPD and 498 normal controls were recruited. Subsequently, five SNPs (rs3804795, rs2290610, rs13097407, rs334782, and rs3856850) in the IL5RA gene were genotyped. Logistic analysis examined the association of five single nucleotide polymorphisms (SNPs) in IL5RA with the risk of COPD under various genetic models. Furthermore, the association between IL5RA and susceptibility to COPD was comprehensively analyzed with stratification based on age, sex, smoking, and alcohol consumption. Our study showed that IL5RA rs13097407 reduced susceptibility to COPD (OR = 0.43, p < 0.001, p (FDR)< 0.001). On the other hand, rs3856850 was associated with an increased risk of COPD (OR = 1.71, p = 0.002, p (FDR) = 0.002). Interestingly, the effect of IL5RA SNPs on susceptibility to COPD was found to be influenced by factors such as sex and smoking. IL5RA gene variants were significantly associated with susceptibility to COPD.

Keratin 15 protects against cigarette smoke-induced epithelial mesenchymal transformation by MMP-9

BACKGROUND

Chronic obstructive pulmonary disease (COPD), a chronic inflammatory lung disease, is a leading cause of morbidity and mortality worldwide. Prolonged cigarette smoking (CS) that causes irreversible airway remodeling and significantly reduces lung function is a major risk factor for COPD. Keratin15+ (Krt15+) cells with the potential of self-renewal and differentiation properties have been implicated in the maintenance, proliferation, and differentiation of airway basal cells; however, the role of Krt15 in COPD is not clear.

METHODS

Krt15 knockout (Krt15-/-) and wild-type (WT) mice of C57BL/6 background were exposed to CS for six months to establish COPD models. Krt15-CrePGR;Rosa26-LSL-tdTomato mice were used to trace the fate of the Krt15+ cells. Hematoxylin and eosin (H&E) and Masson stainings were performed to assess histopathology and fibrosis, respectively. Furthermore, lentivirus-delivered short hairpin RNA (shRNA) was used to knock down KRT15 in human bronchial epithelial (HBE) cells stimulated with cigarette smoke extract (CSE). The protein expression was assessed using western blot, immunohistochemistry, and enzyme-linked immunosorbent assay.

RESULTS

Krt15-/- CS mice developed severe inflammatory cell infiltration, airway remodeling, and emphysema. Moreover, Krt15 knockout aggravated CS-induced secretion of matrix metalloproteinase-9 (MMP-9) and epithelial-mesenchymal transformation (EMT), which was reversed by SB-3CT, an MMP-9 inhibitor. Consistent with this finding, KRT15 knockdown promoted MMP-9 expression and EMT progression in vitro. Furthermore, Krt15+ cells gradually increased in the bronchial epithelial cells and were transformed into alveolar type II (AT2) cells.

CONCLUSION

Krt15 regulates the EMT process by promoting MMP-9 expression and protects the lung tissue from CS-induced injury, inflammatory infiltration, and apoptosis. Furthermore, Krt15+ cells transformed into AT2 cells to protect alveoli. These results suggest Krt15 as a potential therapeutic target for COPD.

Optimizing inhaled corticosteroid use in patients with chronic obstructive pulmonary disease: assessing blood eosinophils, neutrophil-to-lymphocyte ratio, and mortality outcomes in US adults

Objective

Accurate biomarkers for evaluating mortality rates in patients with chronic obstructive pulmonary disease (COPD) remain scarce. This study aimed to explore the relationships between mortality rates in patients with COPD and blood eosinophil counts, neutrophil counts, and lymphocyte counts, along with the neutrophil-to-lymphocyte ratio (NLR). Additionally, we sought to identify the optimal response values for these biomarkers when utilizing inhaled corticosteroids (ICS).

Methods

Utilizing a nationally representative, multistage cross-sectional design and mortality correlation study, we analyzed data from the National Health and Nutrition Examination Survey (NHANES) 1999-2018 involving US adults aged 40 years or older with COPD. The primary endpoint was all-cause mortality, with Kaplan-Meier survival curves and restricted cubic splines applied to illustrate the relationship between leukocyte-based inflammatory markers and mortality. The analysis was conducted in 2023.

Results

Our analysis included 1,715 COPD participants, representing 6,976,232 non-institutionalized US residents [weighted mean age (SE), 62.09 (0.28) years; range, 40-85 years]. Among the participants, men constituted 50.8% of the population, and the weighted mean follow-up duration was 84.9 months. In the ICS use group, the weighted proportion of participants over 70 years old was significantly higher compared with the non-ICS use group (31.39% vs 25.52%, p < 0.0001). The adjusted hazard ratios for all-cause mortality related to neutrophil counts, lymphocyte counts, and NLR were 1.10 [95% confidence interval (CI), 1.04-1.16, p < 0.001], 0.83 (95% CI, 0.71-0.98; p = 0.03), and 1.10 (95% CI, 1.05-1.15; p < 0.0001), respectively. Optimal ICS response was linked with higher levels of eosinophil count (≥240 cells/μL), neutrophil count (≥3,800 cells/μL), NLR (≥4.79), and lower levels of lymphocyte count (<2,400 cells/μL).

Conclusion

Adjusted baseline neutrophil, lymphocyte counts, and NLR serve as independent risk factors for all-cause mortality in patients with COPD. Further, ICS application appears to mitigate mortality risk, particularly when NLR levels reach 4.79 or higher, underlining the importance of ICS in COPD management.

Satisfaction with medication in older adult patients with chronic respiratory diseases: a multicenter cross-sectional observational study

Purpose

To gain insight into medication satisfaction and factors associated with chronic respiratory disease, particularly chronic obstructive pulmonary disease (COPD) in older adults, focusing on public health issues and improving the health of the older adult population.

Methods

This cross-sectional study was conducted from October 2022 to November 2022 in 24 hospitals in different regions of Hunan Province, China. Older adult patient treatment satisfaction was assessed using the Treatment Satisfaction Questionnaire for Medication version II. Multiple regression analysis was used to identify factors independently associated with patient treatment satisfaction.

Results

Only 15.9% of all patients scored above 80 in the effectiveness domain, while 11.6 and 16.5% scored above 80 in the convenience and global satisfaction domains, respectively, while 17.3% reported having side effects. Interstitial lung disease was associated with lower drug satisfaction than other disorders (p < 0.05). Multifactorial regression analysis showed that age, education background, profession, and smoking status were independently associated with satisfaction among patients with chronic respiratory diseases (p < 0.05). Education background, profession, CAT score, number of acute exacerbations, duration of home oxygenation and duration of home ventilator use were independently associated with satisfaction in patients with COPD (p < 0.05).

Conclusion

Low satisfaction with chronic respiratory drug therapy was associated with age, education background, profession and smoking status. Satisfaction was lower for patients with interstitial lung disease. For COPD, CAT score, education background, profession, number of acute exacerbations, home oxygen and ventilator use influence satisfaction. Clinicians can identify appropriate patients and communicate effectively with them throughout treatment and follow-up, vigorously promote smoking cessation and home oxygen therapy, increase medication satisfaction, especially among older adults, and in turn improve public health and the quality of life of older adults.

Rational use of inhaled corticosteroids for the treatment of COPD

Inhaled corticosteroids (ICS) are the mainstay of treatment for asthma, but their role in chronic obstructive pulmonary disease (COPD) is debated. Recent randomised controlled trials (RCTs) conducted in patients with COPD and frequent or severe exacerbations demonstrated a significant reduction (~25%) in exacerbations with ICS in combination with dual bronchodilator therapy (triple therapy). However, the suggestion of a mortality benefit associated with ICS in these trials has since been rejected by the European Medicines Agency and US Food and Drug Administration. Observational evidence from routine clinical practice demonstrates that dual bronchodilation is associated with better clinical outcomes than triple therapy in a broad population of patients with COPD and infrequent exacerbations. This reinforces guideline recommendations that ICS-containing maintenance therapy should be reserved for patients with frequent or severe exacerbations and high blood eosinophils (~10% of the COPD population), or those with concomitant asthma. However, data from routine clinical practice indicate ICS overuse, with up to 50-80% of patients prescribed ICS. Prescription of ICS in patients not fulfilling guideline criteria puts patients at unnecessary risk of pneumonia and other long-term adverse events and also has cost implications, without any clear benefit in disease control. In this article, we review the benefits and risks of ICS use in COPD, drawing on evidence from RCTs and observational studies conducted in primary care. We also provide a practical guide to prescribing ICS, based on the latest global treatment guidelines, to help primary care providers identify patients for whom the benefits of ICS outweigh the risks.

Effective Component Compatibility of Bufei Yishen Formula III Which Regulates the Mucus Hypersecretion of COPD Rats via the miR-146a-5p/EGFR/MEK/ERK Pathway

Background

The effective-component compatibility of Bufei Yishen formula III (ECC-BYF III) with 5 ingredients (ginsenoside Rh1, astragaloside, icariin, nobiletin, and paeonol) has been shown to protect against chronic obstructive pulmonary disease (COPD). The present study aimed to observe the effects of ECC-BYF III in a COPD rat model and dissect its potential mechanisms in regulating mucus hypersecretion via the miR-146a-5p/epidermal growth factor receptor (EGFR)/MEK/ERK pathway.

Methods

COPD model rats were treated with normal saline, ECC-BYF III, or N-acetylcysteine (NAC). Pulmonary function, lung tissue histology with H & E and AB-PAS staining, expression levels of interleukin (IL)-4, IL-6, IL-1β, MUC5AC, MUC5B, and FOXA2 in lung tissues and the mRNA and proteins involved in the miR-146a-5p/EGFR/MEK/ERK pathway were evaluated.

Results

The COPD rats showed a significant decrease in the pulmonary function and serious pathological damage to the lung tissue. ECC-BYF III and NAC significantly improved the ventilation function and small airway pathological damage in the COPD rats. The goblet cells and the expression levels of IL-1β, IL-6, MUC5AC, and MUC5B were increased in the COPD rats and were significantly decreased after ECC-BYF III or NAC intervention. The expression levels of IL-4 and FOXA2 in the COPD rats were markedly decreased and were improved in the ECC-BYF III and NAC groups. ECC-BYF III appeared to have a potent effect in restoring the reduced expression of miR-146a-5p. The increased phosphorylation levels of EGFR, MEK, and ERK1/2 and the protein expression levels of SPDEF in the lungs of COPD rats could be significantly reduced by ECC-BYF III.

Conclusions

ECC-BYF III has a significant effect in improving the airway mucus hypersecretion in COPD model rats, as well as a protective effect against limited pulmonary function and injured lung histopathology. The protective effect of ECC-BYF III in reducing airway mucus hypersecretion in COPD may involve the miR-146a-5p/EGFR/MEK/ERK pathway.

Analysis of the Clinical Efficacy and Molecular Mechanism of Xuefu Zhuyu Decoction in the Treatment of COPD Based on Meta-Analysis and Network Pharmacology

Background

Chronic obstructive pulmonary disease (COPD) is becoming a major public health burden worldwide. It is urgent to explore more effective and safer treatment strategy for COPD. Notably, Xuefu Zhuyu Decoction (XFZYD) is widely used to treat respiratory system diseases, including COPD, in China.

Objective

This study is aimed at comprehensively evaluating the therapeutic effects and molecular mechanism of XFZYD on COPD.

Methods

Original clinical studies were searched from eight literature databases. Meta-analysis was conducted using the Review Manager software (version 5.4.1). Network pharmacology and molecular docking experiments were utilized to explore the mechanisms of action of XFZYD.

Results

XFZYD significantly enhanced the efficacy of clinical treatment and improved the pulmonary function and hypoventilation of COPD patients. In addition, XFZYD significantly improved the hypercoagulability of COPD patients. The subgroup analysis suggested that XFZYD exhibited therapeutic effects on both stable and acute exacerbation of COPD. XFZYD exerted its therapeutic effects on COPD through multicomponent, multitarget, and multipathway characteristics. The intervention of the PI3K-AKT pathway may be the critical mechanism.

Conclusion

The application of XFZYD based on symptomatic relief and supportive treatment is a promising clinical decision. More preclinical and clinical studies are still needed to evaluate the safety and therapeutic effects of long-term use of XFZYD on COPD.

Discovery of Clinical Candidate CHF-6366: A Novel Super-soft Dual Pharmacology Muscarinic Antagonist and β2 Agonist (MABA) for the Inhaled Treatment of Respiratory Diseases

The development of molecules embedding two distinct pharmacophores acting as muscarinic antagonists and β₂ agonists (MABAs) promises to be an excellent opportunity to reduce formulation issues and boost efficacy through cross-talk and allosteric interactions. Herein, we report the results of our drug discovery campaign aimed at improving the therapeutic index of a previous MABA series by exploiting the super soft-drug concept. The incorporation of a metabolic liability, stable at the site of administration but undergoing rapid systemic metabolism, to generate poorly active and quickly eliminated fragments was pursued. Our SAR studies yielded MABA 29, which demonstrated a balanced in vivo profile up to 24 h, high instability in plasma and the liver, as well as sustained exposure in the lung. In vitro safety and non-GLP toxicity studies supported the nomination of 29 (CHF-6366) as a clinical candidate, attesting to the successful development of a novel super-soft MABA compound.

Study on the Management of the Health Status of Patients with Stable Chronic Obstructive Pulmonary Disease Treated with Double Bronchodilator

Objective

To investigate the patients with stable chronic obstructive pulmonary disease (COPD) to understand the use of double bronchodilator therapy and influencing factors.

Methods

The patients with stable COPD who used double bronchodilators were continuously enrolled in our hospital. The information of demographic characteristics, medical history, physical examination, drug use, and correct treatment methods after using inhaled drugs were collected by standardized questionnaire. Measurement data between groups were compared by using the independent sample t-test, and counting data between groups were compared by using the chi-square test.

Results

A total of 102 patients were included in the analysis. The proportion of patients with stable COPD who correctly used dual bronchodilators was 59.8% (61 patients). In the GOLD classification, the correct use rate of C-level patients was 69.8%, which was significantly higher than the used correct rate of D-level patients (49.0%) (P=0.032). In the age group, the correct use rate of patients <65 years old was 72.1%, which was significantly higher than that of patients ≥65 years old (50.8%) (P=0.031). In addition, education level, duration of drug use, and drug type may also affect the correct use of drugs, but no significant statistical significance was found between the groups of these three factors (P > 0.05).

Conclusion

There is still a gap between the treatment of dual bronchodilators in patients with stable COPD and the guidelines, so the management of COPD should be strengthened. Besides, the correct use rate could be affected by the GOLD classification and age.

Improving Physiological, Physical, and Psychological Health Outcomes: A Narrative Review in US Veterans with COPD

The Veterans Health Administration (VHA) is the largest integrated healthcare system in the United States (US) providing healthcare to an increasing number of middle-aged and older adults who remain at greater risk for chronic obstructive pulmonary disease (COPD) compared to their civilian counterparts. The VHA has obligated research funds, drafted clinical guidelines, and built programmatic infrastructure to support the diagnosis, treatment, and care management of Veterans with COPD. Despite these efforts, COPD remains a leading cause of morbidity and mortality in Veterans. This paper provides a narrative review of research conducted with US Veteran samples targeting improvement in COPD outcomes. We review key physiological, physical, and psychological health outcomes and intervention research that included US Veteran samples. We conclude with a discussion of directions for future research to continue advancing the treatment of COPD in Veterans and inform advancements in COPD research within and outside the VHA.

Inhaled Phosphodiesterase Inhibitors for the Treatment of Chronic Obstructive Pulmonary Disease

Phosphodiesterase (PDE) 4 inhibitors prevent the metabolism of cyclic adenosine monophosphate, thereby reducing inflammation. Inhaled PDE4 inhibitors aim to restrict systemic drug exposure to enhance the potential for clinical benefits (in the lungs) versus adverse events (systemically). The orally administered PDE4 inhibitor roflumilast reduces exacerbation rates in the subgroup of chronic obstructive pulmonary disease patients with a history of exacerbations and the presence of chronic bronchitis, but can cause PDE4 related adverse effects due to systemic exposure. CHF6001 is an inhaled PDE4 inhibitor, while inhaled ensifentrine is an inhibitor of both PDE3 and PDE4; antagonism of PDE3 facilitates smooth muscle relaxation and hence bronchodilation. These inhaled PDE inhibitors have both reported positive findings from early phase clinical trials, and have been well tolerated. Longer term trials are needed to firmly establish the clinical benefits of these drugs.

Airway Bacteria Quantification Using Polymerase Chain Reaction Combined with Neutrophil and Eosinophil Counts Identifies Distinct COPD Endotypes

BACKGROUND

Chronic obstructive pulmonary disease (COPD) inflammatory endotypes are associated with different airway microbiomes. We used quantitative polymerase chain reaction (qPCR) analysis of sputum samples to establish the bacterial load upper limit in healthy controls; these values determined the bacterial colonisation prevalence in a longitudinal COPD cohort. Bacteriology combined with sputum inflammatory cells counts were used to investigate COPD endotypes.

METHODS

Sixty COPD patients and 15 healthy non-smoking controls were recruited. Sputum was analysed by qPCR (for Haemophilus influenzae, Moraxella catarrhalis, Streptococcus pneumoniae and Psuedomonas aeruginosa) and sputum differential cell counts at baseline and 6 months.

RESULTS

At baseline and 6 months, 23.1% and 25.6% of COPD patients were colonised with H. influenzae, while colonisation with other bacterial species was less common, e.g., S. pneumoniae-1.9% and 5.1%, respectively. H. influenzae + ve patients had higher neutrophil counts at baseline (90.1% vs. 67.3%, p < 0.01), with similar results at 6 months. COPD patients with sputum eosinophil counts ≥3% at ≥1 visit rarely showed bacterial colonisation.

CONCLUSIONS

The prevalence of H. influenzae colonisation was approximately 25%, with low colonisation for other bacterial species. H. influenzae colonisation was associated with sputum neutrophilia, while eosinophilic inflammation and H. influenzae colonisation rarely coexisted.