Analysis of PM2.5 inorganic and organic constituents to resolve contributing sources in Seoul, South Korea and Beijing, China and their possible associations with cytokine IL-8.

China and South Korea are the most polluted countries in East Asia due to significant urbanization and extensive industrial activities. As neighboring countries, collaborative management plans to maximize public health in both countries can be helpful in reducing transboundary air pollution. To support such planning, PM2.5 inorganic and organic species were determined in simultaneously collected PM2.5 integrated filters. The resulting data were used as inputs to positive matrix factorization, which identified nine sources at the ambient air monitoring sites in both sites. Secondary nitrate, secondary sulfate/oil combustion, soil, mobile, incinerator, biomass burning, and secondary organic carbon (SOC) were found to be sources at both sampling sites. Industry I and II were only identified in Seoul, whereas combustion and road dust sources were only identified in Beijing. A subset of samples was selected for exposure assessment. The expression levels of IL-8 were significantly higher in Beijing (167.7 pg/mL) than in Seoul (72.7 pg/mL). The associations between the PM2.5 chemical constituents and its contributing sources with PM2.5-induced inflammatory cytokine (interleukin-8, IL-8) levels in human bronchial epithelial cells were investigated. For Seoul, the soil followed by the secondary nitrate and the biomass burning showed increase with IL-8 production. However, for the Beijing, the secondary nitrate exhibited the highest association with IL-8 production and SOC and biomass burning showed modest increase with IL-8. As one of the highest contributing sources in both cities, secondary nitrate showed an association with IL-8 production. The soil source having the strongest association with IL-8 production was found only for Seoul, whereas SOC showed a modest association only for Beijing. This study can provide the scientific basis for identifying the sources to be prioritized for control to provide effective mitigation of particulate air pollution in each city and thereby improve public health.

Del-1 Plays a Protective Role against COPD Development by Inhibiting Inflammation and Apoptosis.

Neutrophilic inflammation is a prominent feature of chronic obstructive pulmonary disease (COPD). Developmental endothelial locus-1 (Del-1) has been reported to limit excessive neutrophilic inflammation by inhibiting neutrophil adhesion to the vascular endothelial cells. However, the effects of Del-1 in COPD are not known. We investigated the role of Del-1 in the pathogenesis of COPD. Del-1 protein expression was decreased in the lungs of COPD patients, especially in epithelial cells and alveolar macrophages. In contrast to human lung tissue, Del-1 expression was upregulated in lung tissue from mice treated with cigarette smoke extracts (CSE). Overexpression of Del-1 significantly suppressed IL-8 release and apoptosis in CSE-treated epithelial cells. In contrast, knockdown of Del-1 enhanced IL-8 release and apoptosis. In macrophages, overexpression of Del-1 significantly suppressed inflammatory cytokine release, and knockdown of Del-1 enhanced it. This anti-inflammatory effect was mediated by inhibiting the phosphorylation and acetylation of NF-κB p65. Nuclear factor erythroid 2-related factor 2 (Nrf2) activators, such as quercetin, resveratrol, and sulforaphane, increased Del-1 in both cell types. These results suggest that Del-1, mediated by Nrf2, plays a protective role against the pathogenesis of COPD, at least in part through anti-inflammatory and anti-apoptotic effects.

Machine Learning-Based Proteomics Reveals Ferroptosis in COPD Patient-Derived Airway Epithelial Cells Upon Smoking Exposure.

BACKGROUND: Proteomics and genomics studies have contributed to understanding the pathogenesis of chronic obstructive pulmonary disease (COPD), but previous studies have limitations. Here, using a machine learning (ML) algorithm, we attempted to identify pathways in cultured bronchial epithelial cells of COPD patients that were significantly affected when the cells were exposed to a cigarette smoke extract (CSE). METHODS: Small airway epithelial cells were collected from patients with COPD and those without COPD who underwent bronchoscopy. After expansion through primary cell culture, the cells were treated with or without CSEs, and the proteomics of the cells were analyzed by mass spectrometry. ML-based feature selection was used to determine the most distinctive patterns in the proteomes of COPD and non-COPD cells after exposure to smoke extract. Publicly available single-cell RNA sequencing data from patients with COPD (GSE136831) were used to analyze and validate our findings. RESULTS: Five patients with COPD and five without COPD were enrolled, and 7,953 proteins were detected. Ferroptosis was enriched in both COPD and non-COPD epithelial cells after their exposure to smoke extract. However, the ML-based analysis identified ferroptosis as the most dramatically different response between COPD and non-COPD epithelial cells, adjusted P value = 4.172 × 10-6, showing that epithelial cells from COPD patients are particularly vulnerable to the effects of smoke. Single-cell RNA sequencing data showed that in cells from COPD patients, ferroptosis is enriched in basal, goblet, and club cells in COPD but not in other cell types. CONCLUSION: Our ML-based feature selection from proteomic data reveals ferroptosis to be the most distinctive feature of cultured COPD epithelial cells compared to non-COPD epithelial cells upon exposure to smoke extract.

Developmental endothelial locus-1 as a potential biomarker for the incidence of acute exacerbation in patients with chronic obstructive pulmonary disease.

BACKGROUND: Despite the high disease burden of chronic obstructive pulmonary disease (COPD) and risk of acute COPD exacerbation, few COPD biomarkers are available. As developmental endothelial locus-1 (DEL-1) has been proposed to possess beneficial effects, including anti-inflammatory effects, we hypothesized that DEL-1 could be a blood biomarker for COPD. OBJECTIVE: To elucidate the role of plasma DEL-1 as a biomarker of COPD in terms of pathogenesis and for predicting acute exacerbation. METHODS: Cigarette smoke extract (CSE) or saline was intratracheally administered to wild-type (WT) and DEL-1 knockout (KO) C57BL/6 mice. Subsequently, lung sections were obtained to quantify the degree of emphysema using the mean linear intercept (MLI). Additionally, plasma DEL-1 levels were compared between COPD and non-COPD participants recruited in ongoing prospective cohorts. Using negative binomial regression analysis, the association between the plasma DEL-1 level and subsequent acute exacerbation risk was evaluated in patients with COPD. RESULTS: In the in vivo study, DEL-1 KO induced emphysema (KO saline vs. WT saline; P = 0.003) and augmented CSE-induced emphysema (KO CSE vs. WT CSE; P < 0.001) in 29 mice. Among 537 participants, patients with COPD presented plasma log (DEL-1) levels lower than non-COPD participants (P = 0.04), especially non-COPD never smokers (P = 0.019). During 1.2 ± 0.3 years, patients with COPD in the lowest quartile of Log(DEL-1) demonstrated an increased risk of subsequent acute exacerbation, compared with those in the highest quartile of Log(DEL-1) (adjusted incidence rate ratio, 3.64; 95% confidence interval, 1.03-12.9). CONCLUSION: Low DEL-1 levels are associated with COPD development and increased risk of subsequent COPD acute exacerbation. DEL-1 can be a useful biomarker in patients with COPD.

Impact of Sleep Duration on Mortality and Quality of Life in Chronic Kidney Disease: Results from the 2007-2015 KNHANES.

INTRODUCTION: In the general population, short and long sleep durations have been associated with adverse health outcomes. However, this association remains unclear in patients with chronic kidney disease (CKD). We examined the relationship of sleep duration to mortality and health-related quality of life (HRQOL) in individuals with CKD. METHODS: A total of 1,783 adults with CKD who participated in the 2007-2015 Korea National Health and Nutrition Examination Survey were analyzed. CKD was defined as an estimated glomerular filtration rate of <60 mL/min per 1.73 m2. Participants were categorized into 3 groups according to self-reported sleep duration: <6 h (short sleepers), 6-8 h, and >8 h (long sleepers). The outcome variables were all-cause mortality and HRQOL. HRQOL was assessed using the European Quality of Life-5 Dimensions (EQ-5D) index. RESULTS: During a median of 6.4 years, 481 (27%) deaths occurred. In unadjusted Cox regression analysis, long sleepers with CKD had an increased risk of death (hazard ratio [HR], 1.62; 95% confidence interval [CI]: 1.26-2.09). This significant association remained after adjusting for age, sex, and BMI (HR, 1.36; 95% CI: 1.05-1.75); however, it was lost after adjusting for CKD stage, social and lifestyle factors, and presence of comorbidities (HR, 1.15; 95% CI: 0.89-1.49). Compared with 6- to 8-h sleepers with CKD, long sleepers with CKD had significantly worse HRQOL in multivariable linear regression models. The adjusted means of the EQ-5D index were 0.80 (95% CI: 0.77-0.82) for short sleepers, 0.81 (95% CI: 0.80-0.82) for 6- to 8-h sleepers, and 0.76 (95% CI: 0.73-0.79) for long sleepers (p = 0.01). DISCUSSION/CONCLUSION: Long sleep duration is associated with poor HRQOL in Korean adults with CKD. The weak association between long sleep duration and mortality was attenuated after multivariable adjustment in this study.

Cigarette smoke extract decreased basal and lipopolysaccharide-induced expression of MARCO via degradation of p300.

BACKGROUND AND OBJECTIVE: Alveolar macrophages of patients with COPD display impaired cytokine release and diminished phagocytosis. COPD exacerbations exhibit immune dysfunction towards the respiratory pathogens. CS and CSE were reported to aggravate bacterial infections in COPD patients. METHODS: MARCO is highly expressed in lungs and is involved in pathogen clearance. We investigated the effect of CSE on MARCO expression and its regulatory mechanisms. After relevant siRNA transfection and treatment with CSE and/or LPS, we measured the levels of MARCO by q-RT PCR, immunoblotting and flow cytometry. Immunofluorescence staining and immunoprecipitation were used to evaluate the mechanism. RESULTS: CSE decreased LPS-induced expression of MARCO mRNA and protein. Upregulation of MARCO by LPS was Nrf2-dependent. Nrf2 knockdown significantly suppressed LPS-induced increase in MARCO transcripts. CSE did not block nuclear translocation of Nrf2 in LPS-treated cells, but rather CSE itself strongly accumulated Nrf2 in the nucleus through the degradation of its cytoplasmic inhibitor, KEAP1. However, CSE markedly suppressed LPS-induced Nrf2 acetylation. Histone acetyltransferase p300/CBP directly acetylates Nrf2, which augments promoter-specific DNA binding of Nrf2. Our results reveal CSE-induced polyubiquitinylation and subsequent degradation of p300 via the proteasome. Pretreatment with proteasome inhibitors completely blocked CSE-induced degradation of p300 and suppression of MARCO expression. CONCLUSION: These findings suggest that CSE decreases MARCO expression via the proteasomal degradation of p300 in macrophages, which may be in part responsible for impaired bacterial phagocytosis.

Sleep Duration and Its Associations with Mortality and Quality of Life in Chronic Obstructive Pulmonary Disease: Results from the 2007-2015 KNAHNES.

BACKGROUND: While extreme sleep duration negatively affects mortality and health-related quality of life (HRQOL) in general populations, the relationship remains uncertain in patients with chronic obstructive pulmonary disease (COPD). OBJECTIVES: To evaluate the association between sleep duration and mortality and HRQOL in patients with COPD. METHODS: We analyzed 3,349 participants with COPD enrolled in the 2007-2015 Korea National Health and Nutrition Examination Survey (KNHANES). Participants aged 40 years or older with a smoking history and prebronchodilator forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) <0.7 were eligible. The participants were categorized as short sleepers (<6 h), 6-8 h, and long sleepers (>8) according to self-reported sleep duration. The outcome variables were all-cause mortality and HRQOL. HRQOL was measured using the European Quality of Life-5 Dimensions (EQ-5D) index. RESULTS: During a median of 6.5 years, 386 (11.5%) participants died. In unadjusted Cox regression analysis, short sleepers with COPD had an increased risk of death (hazard ratio, 1.35; 95% confidence interval [CI]: 1.07-1.71). However, this association was not significant after adjusting for sociodemographic factors, BMI, FEV1, and comorbidities. In unadjusted and adjusted multiple linear regression, short sleepers had significantly worse HRQOL. The adjusted means of the EQ-5D index were 0.88 (95% CI: 0.87-0.89) for short sleepers, 0.90 (95% CI: 0.90-0.91) for 6- to 8-h sleepers, and 0.89 (95% CI: 0.87-0.91) for long sleepers (p = 0.01). CONCLUSIONS: In patients with COPD, sleep duration was not associated with all-cause mortality. However, short sleep duration was significantly associated with worse HRQOL.

Dexmedetomidine versus midazolam for sedation during endobronchial ultrasound-guided transbronchial needle aspiration: A randomised controlled trial.

BACKGROUND: Desaturation is a common complication of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). Dexmedetomidine (DEX), a commonly used sedative in intensive care, is associated with less respiratory depression compared with other sedatives. OBJECTIVE: We compared DEX with midazolam (MDZ) when used as a sedative during EBUS-TBNA. DESIGN: A randomised, parallel, double-blinded trial. SETTING: A university-affiliated teaching hospital between June 2014 and July 2015. PATIENTS: A total of 102 patients who underwent EBUS-TBNA were randomly allocated to two groups (48 DEX group, 54 MDZ group). INTERVENTIONS: DEX group received 0.25 to 0.75 µg kg-1 h-1 (start with 0.5 µg kg-1 h-1, modulated in three steps from 0.25 to 0.75 µg kg-1 h-1) of DEX after a loading dose of 0.25 µg kg-1 h-1 for 10 min to maintain a Ramsay Sedation Scale (RSS) of 3 to 5. If the patient was agitated, 1 mg of MDZ bolus was used as a rescue drug. Patients in the MDZ group initially received 0.05 mg kg-1 of MDZ as a bolus. For maintenance and rescue, 1 mg of MDZ bolus was used. MAIN OUTCOME MEASURES: The primary outcome was the presence of oxygen desaturation. Secondary outcomes were level of sedation (Ramsay Sedation Scale score), cough score, sedation and procedure satisfaction score. RESULTS: The baseline characteristics of the patients, duration of EBUS-TBNA procedures and the use of rescue MDZ were not different between the groups. There was no significant difference in desaturation events between the DEX and MDZ groups (56.3 and 68.5%, respectively; P = 0.20). The level of sedation and the sedation satisfaction scores were similar between the two groups. However, cough score was significantly lower in the DEX group (41.9 vs. 53.4; P = 0.02). CONCLUSION: The use of DEX during EBUS-TBNA was not superior to MDZ in terms of oxygen desaturation. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT02157818.

Improved Oxygenation After Prone Positioning May Be a Predictor of Survival in Patients With Acute Respiratory Distress Syndrome.

OBJECTIVES: Prone position ventilation improves oxygenation and reduces the mortality of patients with severe acute respiratory distress syndrome. However, there is limited evidence about which patients would gain most survival benefit from prone positioning. Herein, we investigated whether the improvement in oxygenation after prone positioning is associated with survival and aimed to identify patients who will gain most survival benefit from prone positioning in patients with acute respiratory distress syndrome. DESIGN: A retrospective cohort study. SETTING: Medical ICU at a tertiary academic hospital between 2014 and 2020. PATIENTS: Adult patients receiving prone positioning for moderate-to-severe acute respiratory distress syndrome. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The main outcomes were ICU and 28-day mortality. A total of 116 patients receiving prone positioning were included, of whom 45 (38.8%) were ICU survivors. Although there was no difference in PaO2:FIO2 ratio before the first prone session between ICU survivors and nonsurvivors, ICU survivors had a higher PaO2:FIO2 ratio after prone positioning than nonsurvivors, with significant between-group difference (p < 0.001). The area under the receiver operating characteristic curve of the percentage change in the PaO2:FIO2 ratio between the baseline and 8-12 hours after the first prone positioning to predict ICU mortality was 0.87 (95% CI, 0.80-0.94), with an optimal cutoff value of 53.5% (sensitivity, 91.5%; specificity, 73.3%). Prone responders were defined as an increase in PaO2:FIO2 ratio of greater than or equal to 53.5%. In the multivariate Cox regression analysis, prone responders (hazard ratio, 0.11; 95% CI, 0.05-0.25), immunocompromised condition (hazard ratio, 2.15; 95% CI, 1.15-4.03), and Sequential Organ Failure Assessment score (hazard ratio, 1.16; 95% CI, 1.06-1.27) were significantly associated with 28-day mortality. CONCLUSIONS: The PaO2:FIO2 ratio after the first prone positioning differed significantly between ICU survivors and nonsurvivors. The improvement in oxygenation after the first prone positioning was a significant predictor of survival in patients with moderate-to-severe acute respiratory distress syndrome.

Validation of age, PaO2/FlO2 and plateau pressure score in Korean patients with acute respiratory distress syndrome: a retrospective cohort study.

BACKGROUND: A predictive scoring system for acute respiratory distress syndrome (ARDS) patients, which incorporates age, PaO2/FlO2, and plateau pressure, APPS, was developed recently. It was validated externally in a Caucasian population but has not been studied in Asian populations. The aim of this study was to validate APPS in Korean ARDS patients. METHODS: We retrospectively reviewed the medical records of patients who were diagnosed with ARDS using the Berlin criteria and admitted to the medical ICU at Seoul National University Hospital from January 2015 to December 2016. The validation of the APPS was performed by evaluating its calibration and predictive accuracy. Its calibration was plotted and quantified using the Hosmer-Lemeshow test. Its predictive accuracy was assessed by calculating the area under the receiver operating characteristics (AUC-ROC) curve. RESULTS: A total of 116 patients were analyzed, 32 of whom survived. Of the 116 patients, 11 (9.5%) were classified as APPS grade 1 (score 3-4), 88 (75.9%) as grade 2 (score 5-7) and 17 (14.6%) as grade 3 (score 8-9). In-hospital mortality was 27.3% for grade 1, 73.9% for grade 2 and 94.1% for grade 3 (P for trend < 0.001). The APPS was well calibrated (Hosmer-Lemeshow test, P = 0.578) and its predictive accuracy was acceptable (AUC-ROC 0.704, 95% confidence interval 0.599-0.809). CONCLUSIONS: The APPS predicted in-hospital mortality in Korean patients with ARDS with similar power to its application in a Western population and with acceptable predictive accuracy. TRIAL REGISTRATION: Retrospectively registered.

Rapid Muscle Loss Negatively Impacts Survival in Critically Ill Patients With Cirrhosis.

PURPOSE: To assess the impact of rapid muscle loss before admission to intensive care unit (ICU) in critically ill patients with cirrhosis. MATERIALS AND METHODS: Patients with cirrhosis who had undergone 2 or more recent computed tomography scans before admission to the medical ICU were included. Muscle cross-sectional area at the level of the third lumbar vertebra was quantified using OsiriX software. The rate of muscle mass change and skeletal muscle index (SMI) were also calculated. Multivariable Cox proportional hazards regression was used to evaluate the association between muscle loss and mortality. RESULTS: Among 125 patients, 113 (90.4%) patients were classified as having sarcopenia. The mean body mass index was 22.6 (3.9) kg/m2. Thirty-nine (31.2%) patients were within the normal range for muscle mass change, while 86 (68.8%) patients demonstrated rapid decline in muscle mass before admission to the ICU. Patients with rapid muscle loss showed high ICU mortality (59.3%) and in-hospital mortality (77.9%). Multivariate Cox analysis showed that ICU mortality and in-hospital mortality were independently associated with malignancy, Acute Physiology and Chronic Health Evaluation (APACHE) II score, SMI, and rapid muscle loss. CONCLUSION: Rapid muscle decline is correlated with increased ICU mortality and in-hospital mortality in critically ill patients with cirrhosis.

Sleep duration and health-related quality of life in Korean adults: 2007-2015 Korea National Health and Nutrition Examination Survey.

PURPOSE: To evaluate the association of sleep duration with health-related quality of life (HRQOL) and examine the influence of age, sex, and common comorbidities on this association. METHODS: Using appropriate survey design, we analyzed 50,181 adults who participated in the 2007-2015 Korea National Health and Nutrition Examination Survey. Participants were categorized into five groups according to self-reported sleep duration ≤ 5 (short sleeper), 6, 7, 8, and ≥ 9 h (long sleeper). HRQOL was measured with the European Quality of Life-5 Dimensions (EQ-5D) index and visual analogue scale (VAS). RESULTS: In multiple linear regression, short sleep duration was associated with lower EQ-5D index (ß = - 0.024; 95% confidence interval [CI], - 0.027 to - 0.021) and lower EQ-VAS (ß = - 3.0; 95% CI, - 3.7 to - 2.3), and long sleep duration was associated with lower EQ-5D index (ß = - 0.016; 95% CI, - 0.021 to - 0.011) and lower EQ-VAS (ß = - 2.2; 95% CI, - 3.1 to - 1.3) compared with 7-h sleepers. Old-age (≥ 65 years old) short and long sleepers had significantly lower EQ-5D index than those of < 65 years old. When separated according to sex, men with long sleep and women with short sleep showed the lowest EQ-5D index. Short and long sleepers with hypertension, diabetes, hypercholesterolemia, cardiovascular disease, or depression showed significantly lower EQ-5D index than those without comorbidities. CONCLUSIONS: Extreme sleep duration was associated with poor HRQOL. Short and long sleepers with old age and comorbidities had significantly lower HRQOL than those without such conditions.

Mortality risk and causes of death in patients with non-cystic fibrosis bronchiectasis.

BACKGROUND: All-cause mortality risk and causes of death in bronchiectasis patients have not been fully investigated. The aim of this study was to compare the mortality risk and causes of death between individuals with bronchiectasis and those without bronchiectasis. METHODS: Patients with or without bronchiectasis determined based on chest computed tomography (CT) at one centre between 2005 and 2016 were enrolled. Among the patients without bronchiectasis, a control group was selected after applying additional exclusion criteria. We compared the mortality risk and causes of death between the bronchiectasis and control groups without lung disease. Subgroup analyses were also performed according to identification of Pseudomonas or non-tuberculous mycobacteria, airflow limitation, and smoking status. RESULTS: Of the total 217,702 patients who underwent chest CT, 18,134 bronchiectasis patients and 90,313 non-bronchiectasis patients were included. The all-cause mortality rate in the bronchiectasis group was 1608.8 per 100,000 person-years (95% confidence interval (CI), 1531.5-1690.0), which was higher than that in the control group (133.5 per 100,000 person-years; 95% CI, 124.1-143.8; P < 0.001). The bronchiectasis group had higher all-cause (adjusted hazard ratio (aHR), 1.26; 95% CI, 1.09-1.47), respiratory (aHR, 3.49; 95% CI, 2.21-5.51), and lung cancer-related (aHR, 3.48; 95% CI, 2.33-5.22) mortality risks than the control group. In subgroup analysis, patients with airflow limitation and ever smokers showed higher all-cause mortality risk among bronchiectasis patients. Therefore, we observed significant interrelation between bronchiectasis and smoking, concerning the risks of all-cause mortality (P for multiplicative interaction, 0.030, RERI, 0.432; 95% CI, 0.097-0.769) and lung cancer-related mortality (RERI, 8.68; 95% CI, 1.631-15.736). CONCLUSION: Individuals with bronchiectasis had a higher risk of all-cause, respiratory, and lung cancer-related mortality compared to control group. The risk of all-cause mortality was more prominent in those with airflow limitation and in ever smokers.

Serum Uric Acid Level as a Prognostic Marker in Patients With Acute Respiratory Distress Syndrome.

PURPOSE:: Uric acid acts as both a pathogenic inflammatory mediator and an antioxidative agent. Several studies have shown that uric acid level correlates with the incidence, severity, and prognosis of pulmonary diseases. However, the association between uric acid level and acute respiratory distress syndrome (ARDS) has not been studied. This study was conducted to elucidate how serum uric acid level is related with clinical prognosis of ARDS. METHODS:: A retrospective cohort study with propensity score matching was conducted at a medical intensive care unit of a tertiary teaching hospital. The medical records of patients diagnosed with ARDS admitted from 2005 through 2011 were reviewed. RESULTS:: Two hundred thirty-seven patients with ARDS met the inclusion criteria. Patients with a serum uric acid level <3.0 mg/dL were classified into the low uric acid group, and those with a level ≥3 mg/dL were classified into the normal to high uric acid group. We selected 40 patients in each group using propensity score matching. A higher percentage of patients in the low uric acid group experienced clinical improvement in ARDS. More patients died from sepsis in the normal to high uric acid group. Kaplan-Meier analysis showed that a low serum uric acid level was significantly associated with better survival rate. CONCLUSION:: In patients with ARDS, a low serum uric acid level may be a prognostic marker of a low risk of in-hospital mortality.

Diagnostic and prognostic values of serum activin-a levels in patients with acute respiratory distress syndrome.

BACKGROUND: We aimed to evaluate whether serum activin-A levels are elevated and have any value in predicting severity and prognosis in acute respiratory distress syndrome (ARDS). METHODS: Retrospective cohort study was performed with patients who were admitted to MICU with diagnosis of ARDS and have serum samples stored within 48 h of Intensive care unit (ICU) admission between March 2013 and December 2016 at a single tertiary referral hospital. Serum activin-A levels were measured with ELISA kit, and were compared with those of normal healthy control and non-ARDS sepsis patients. RESULTS: Total 97 ARDS patients were included for the study. Levels of Activin-A were elevated in ARDS patients compared to those of healthy controls (Log-transformed activin-A levels 2.89 ± 0.36 vs. 2.34 ± 0.11, p < 0.001, absolute activin-A levels 1525.6 ± 1060.98 vs. 225.9 ± 30.1, p = 0.016) and non-ARDS sepsis patients (Log-transformed activin-A levels 2.89 ± 0.36 vs. 2.73 ± 0.34, p = 0.002, Absolute activin-A levels 1525.6 ± 1060.98 vs. 754.8 ± 123.5 pg/mL, p = 0.036). When excluding five outliers with extremely high activin-A levels, activin-A showed statistically significant correlation with in-hospital mortalities (In-hospital survivors 676.2 ± 407 vs. non-survivors 897.9 ± 561.9 pg/mL, p = 0.047). In predicting in-hospital mortality, serum activin-A concentrations showed superior area under curve compared to that of Acute physiologic and chronic health evaluation II scores (0.653; 95% CI [0541, 0.765] vs. 0.591, 95% CI [0.471, 0.710]). With cut-off level of 708 pg/mL, those with high serum activin-A levels had more than twofold increased risk of in-hospital mortalities. However, those relations were missing when outliers were in. CONCLUSIONS: Serum activin-A levels in ARDS patients are elevated. However, its levels are weakly associated with ARDS outcomes.

Exogenous neutrophil elastase enters bronchial epithelial cells and suppresses cigarette smoke extract-induced heme oxygenase-1 by cleaving sirtuin 1.

An imbalance between oxidative stress and antioxidant activity plays an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD). Cigarette smoke, a major risk factor of COPD, induces cellular oxidative stress, but levels of antioxidants such as heme oxygenase-1 (HO-1) are reduced in individuals with severe COPD. In this study, we evaluated the molecular mechanism of reduced HO-1 expression in human bronchial epithelial cells. We found that cigarette smoke extract (CSE) increases HO-1 levels via activation of NFE2-related factor 2 (Nrf2). However, pretreating cells with the protease neutrophil elastase (NE) suppressed the CSE-induced expression of HO-1 mRNA and protein. NE also decreased the sirtuin 1 (SIRT1) level, but did not inhibit CSE-induced nuclear translocation and DNA-binding activity of Nrf2. Transfection of cells with a Myc/His-tagged SIRT1 expression vector completely blocked the NE-mediated suppression of HO-1 expression. We further noted that the NE-induced down-regulation of SIRT1 was not due to decreased transcription or proteasomal/lysosomal degradation or loss of solubility. Immunofluorescence staining revealed that NE enters the cell cytoplasm, and we observed that NE directly cleaved SIRT1 in vitro, indicating that SIRT1 levels are decreased via direct degradation by internalized NE. Of note, we observed decreased SIRT1 levels in NE-treated primary human bronchial epithelial cells and in lung homogenates from both smokers and patients with COPD. In conclusion, NE suppresses CSE-induced HO-1 expression by cleaving SIRT1. This finding indicates the importance of cross-talk between oxidative stress and protease responses in the pathogenesis of COPD.

The cutoff point of clinical chronic obstructive pulmonary disease questionnaire for more symptomatic patients.

BACKGROUND: An adequate threshold for the Clinical Chronic Obstructive Pulmonary Disease (COPD) Questionnaire (CCQ) defining more symptomatic COPD patients has not been determined. We aimed to determine the efficacy of the CCQ and the appropriate CCQ threshold for more symptomatic COPD patients. METHODS: COPD patients aged > 40 years who smoked/had smoked ≥10 packs/year were prospectively enrolled over 1 year from three South Korean hospitals (n = 126). Correlations between the CCQ and St. George's Respiratory Questionnaire (SGRQ), COPD Assessment Test (CAT), the modified Medical Round Council (mMRC) scale, lung function, and exercise capacity were evaluated. "More symptomatic patients" were those with an SGRQ score ≥ 25. Area under the receiver operating curve and classification and regression tree analyses were performed to determine the CCQ threshold equivalent to an SGRQ score ≥ 25. RESULTS: The CCQ significantly correlated with the SGRQ, CAT, and mMRC scale (r = 0.76, 0.69, and 0.53, respectively). A CCQ cutoff of 1.4 predicted an SGRQ score of 25 better than others. A CCQ score of 1.4 was a significant determinant of an SGRQ score ≥ 25 even after adjusting for potential confounders. CONCLUSIONS: The CCQ was correlated with other symptom indicators, lung function, and exercise capacity. A CCQ cutoff of 1.4 agreed better than CCQ cutoff of 1.0, suggested by guideline, and this cutoff value may identify more symptomatic COPD patients well. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02527486 . Date of registration: December 19, 2014, retrospectively registered.

Which bronchodilator reversibility criteria can predict severe acute exacerbation in chronic obstructive pulmonary disease patients?

BACKGROUND: It is unclear whether various bronchodilator reversibility (BDR) criteria affect the prognosis of chronic obstructive pulmonary disease (COPD). The aim of this study is to evaluate the impact of positive BDR defined according to various BDR criteria on the risk of severe acute exacerbation (AE) in COPD patients. METHODS: Patients from four prospective COPD cohorts in South Korea who underwent follow-up for at least 1 year were enrolled in this study. The assessed BDR criteria included the Global Initiative for Chronic Obstructive Lung Disease (GOLD), American Thoracic Society (ATS), American College of Chest Physicians, (ACCP), major criteria of the Spanish definition of asthma-COPD overlap syndrome (ACOS), criteria compatible with ACOS in the Global Initiative for Asthma (GINA), and European Respiratory Society (ERS). The rate of patients with severe AE who required hospitalization within 1 year due to BDR results according to each set of criteria was analyzed using logistic regression models. RESULTS: Among a total of 854 patients, the BDR-positive cases varied according to the criteria used. There was a 3.5% positive BDR rate according to GINA and a 29.9% rate according to the ATS criteria. Positive BDR according to the GOLD criteria was significantly associated with a decreased risk of severe AE (adjusted odds ratio (aOR) = 0.38; 95% Confidence interval (CI) = 0.15-0.93). This result remained statistically significant even in a sensitivity analysis that included only participants with a smoking history of at least 10 pack-years and in the analysis for the propensity score-matched participants. CONCLUSIONS: Among different criteria for positive BDR, the use of the GOLD ones was significantly associated with a decreased risk of severe AE in COPD patients. Increase use of ICS/LABA may have affected this relationship.

Different prevalence and clinical characteristics of asthma-chronic obstructive pulmonary disease overlap syndrome according to accepted criteria.

BACKGROUND: A unified definition of asthma-chronic obstructive pulmonary disease overlap syndrome (ACOS) is not available, which makes it difficult to evaluate the prevalence and clinical features of patients with ACOS. OBJECTIVE: To investigate the prevalence and clinical characteristics of ACOS according to the updated widely accepted diagnostic criteria. METHODS: Participants were enrolled from a prospective cohort study conducted between April 2013 and November 2016 in South Korea. We adopted 4 criteria of ACOS: modified Spanish, American Thoracic Society (ATS) Roundtable criteria, the Latin American Project for the Investigation of Obstructive Lung Disease (PLATINO), and the Global Initiative for Asthma/Global Initiative for Chronic Obstructive Lung Disease (GINA/GOLD) criteria. The prevalence, clinical characteristics, and exacerbations of ACOS were investigated. RESULTS: Among 301 patients with chronic obstructive pulmonary disease, 31.3%, 11.9%, 48.3%, and 46.15% were diagnosed with ACOS according to the modified Spanish, ATS Roundtable criteria, PLATINO, and GINA/GOLD criteria, respectively. Compared with other criteria, patients with ACOS diagnosed according to the modified Spanish criteria had better exercise capacity and lung function at baseline but higher risk of moderate to severe (adjusted hazard ratio, 1.97; 95% confidence interval, 1.14-3.41; P = .01) and total (adjusted odds ratio, 2.10; 95% confidence interval, 1.33-3.31; P < .01) exacerbations during at least a 1-year follow-up period than patients without ACOS. CONCLUSION: The prevalence of ACOS varied according to the diagnostic criteria. Among the different criteria, the modified Spanish criteria could identify patients with more asthmatic features and higher risk of exacerbation. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02527486.