Unique features of non-obstructive emphysema and pure airway obstruction

The Impact of Inhaled Corticosteroids on the Prognosis of Chronic Obstructive Pulmonary Disease

Background

A comprehensive analysis of the effects of inhaled corticosteroids (ICS) on COPD in a real-world setting is required due to safety concerns regarding ICS in COPD. This study aimed to explore the impact of ICS on the prognosis of Asian COPD patients in the real-life world.

Methods

We examined 978 COPD patients registered in the Korean National Health and Nutrition Examination Survey (KNHANES) database and with their data linked to Health Insurance and Review Assessment (HIRA) data. The outcome measures were ascertained by HIRA from January 1, 2009, to December 31, 2012. This study enrolled two arms; ICS users (N = 85, mean age = 66.7 ± 8.9 years) and non-ICS users (N = 893, mean age = 63.7 ± 9.7 years).

Results

Compared to the non-ICS users, the ICS users had a higher rate of pneumonia, tuberculosis, and acute exacerbations (P<0.05). Hospitalization due to respiratory causes was also higher among ICS users (P<0.05). Multivariate analysis showed that acute exacerbation was independently associated with the development of pneumonia (P<0.05), whereas ICS therapy had a tendency to be associated with pneumonia. Another multivariate analysis demonstrated that old age, FEV₁, ICS therapy, and pneumonia were independently associated with the occurrence of acute exacerbation (P<0.05). The concomitant pneumonia (HR = 3.353, P = 0.004) was independently associated with higher mortality (P<0.05).

Conclusion

Our data demonstrated that the ICS users had a higher rate of pneumonia and tuberculosis and the concomitant pneumonia was independently associated with higher mortality, highlighting the importance of cautious and targeted administration of ICS in COPD.

Screening and identification of tissue-infiltrating immune cells and genes for patients with emphysema phenotype of COPD

Objective

To study the tissue-infiltrating immune cells of the emphysema phenotype of chronic obstructive pulmonary disease (COPD) and find the molecular mechanism related to the development of emphysema to offer potential targets for more precise treatment of patients with COPD.

Methods

Combined analyses of COPD emphysema phenotype lung tissue-related datasets, GSE47460 and GSE1122, were performed. CIBERSORT was used to assess the distribution of tissue-infiltrating immune cells. Weighted gene co-expression network analysis (WGCNA) was used to select immune key genes closely related to clinical features. Rt-qPCR experiments were used for the validation of key genes. Emphysema risk prediction models were constructed by logistic regression analysis and a nomogram was developed.

Results

In this study, three immune cells significantly associated with clinical features of emphysema (FEV1 post-bronchodilator % predicted, GOLD Stage, and DLCO) were found. The proportion of neutrophils (p=0.025) infiltrating in the emphysema phenotype was significantly increased compared with the non-emphysema phenotype, while the proportions of M2 macrophages (p=0.004) and resting mast cells (p=0.01) were significantly decreased. Five immune-related differentially expressed genes (DEGs) were found. WGCNA and clinical lung tissue validation of patients with emphysema phenotype were performed to further screen immune-related genes closely related to clinical features. A key gene (SERPINA3) was selected and included in the emphysema risk prediction model. Compared with the traditional clinical prediction model (AUC=0.923), the combined prediction model, including SERPINA3 and resting mast cells (AUC=0.941), had better discrimination power and higher net benefit.

Conclusion

This study comprehensively analyzed the tissue-infiltrating immune cells significantly associated with emphysema phenotype, including M2 macrophages, neutrophils, and resting mast cells, and identified SERPINA3 as a key immune-related gene.

Imbalance Between Injury and Defense in the COPD Emphysematous Phenotype

The chronic obstructive pulmonary disease (COPD) emphysematous phenotype is characterized by destruction of lung tissue structure. Patients with this phenotype usually present with typical emphysema-like changes on chest computed Tomography CT, experience higher mortality and poorer prognosis, and are insensitive to routine pharmacological COPD therapy. However, the pathogenesis for the COPD emphysematous phenotype remains unclear, resulting in diagnostic and therapeutic challenges. The imbalance between injury and defense mechanisms is essential in the progression of many pulmonary diseases. Thus, in this review, we focus on the pathogenesis of the COPD emphysematous phenotype and discuss the pathophysiological processes involved in disease progression, from the perspective of injury and defense imbalance.

Cancer development in patients with COPD: a retrospective analysis of the National Health Insurance Service-National Sample Cohort in Korea

BACKGROUND

COPD is a well-known risk factor for lung cancer, independent of smoking behavior. By investigating the retrospective National Health Insurance Service-National Sample Cohort (NHIS-NSC) in Korea, this study attempted to prove the hypothesis that COPD is a risk factor for major cancers developing outside of the lungs. We also aimed to investigate the environmental factors associated with the development of lung cancer in COPD patients.

METHODS

This study analyzed data from the NHIS-NSC over a 12-year period. Among the 514,795 subjects in the NHIS-NSC, 16,757 patients who were diagnosed with any cancer from 2002 to 2003 were excluded. This cohort enrolled six arms consisting of never-smokers without COPD (N = 313,553), former smokers without COPD (N = 41,359), smokers without COPD (N = 112,627), never-smokers with COPD (N = 7789), former smokers with COPD (N = 1085), and smokers with COPD (N = 2677).

RESULTS

Incident rate of lung cancer per 100,000 person-year was higher according to smoking and COPD (216 in non-COPD and 757 in COPD among never-smokers, 271 in non-COPD and 1266 in COPD among former smokers, 394 in non-COPD and 1560 in COPD among smokers, p <  0.01). Old age, male sex, lower BMI, low exercise level, history of diabetes mellitus, smoking, and COPD were independent factors associated with the development of lung cancer (p <  0.01). Multi-variable analyses showed that COPD, regardless of smoking status, contributed to the development of lung cancer, and colorectal cancer and liver cancer among other major cancers (p <  0.01).

CONCLUSION

Our data suggested that COPD was an independent risk factor for the development of lung cancer, and colorectal cancer and liver cancer among other major cancers in the Korean population, regardless of smoking status.

Comparative analysis of pathophysiological parameters between emphysematous smokers and emphysematous patients with COPD

Emphysematous smokers with normal spirometry form a considerable proportion of the clinical population. However, despite presenting with respiratory symptoms and activity limitation, they cannot be diagnosed with chronic obstructive lung disease (COPD) according to current criteria. Thus, we aimed to determine whether emphysema in smokers has a different pathogenesis from that in patients with COPD. We compared 12 pairs of lung tissue samples from emphysematous patients with normal spirometry and COPD, and determined the degree of emphysema using computed tomography. With a focus on COPD-related pathogenesis, we independently assessed inflammatory response, protease-antiprotease balance, oxidative stress, and apoptosis in both groups. Both groups showed similar pathological changes at a comparable degree of emphysema; the expression of inflammatory factors was comparable, with overexpression of proteases and decreased levels of antiproteases. Moreover, there was no significant difference in the activities of glutathione and superoxide dismutase, and expression of apoptosis-related factors. In conclusion, emphysema in smokers with normal spirometry and in patients with COPD had similar pathogenesis. Forced expiratory volume in 1 second cannot be used as the sole diagnostic criterion in patients with COPD; early intervention is of great importance to such patients.