Association Between Air Pollution and Viral Infection in Severe Acute Exacerbation of Chronic Obstructive Pulmonary Disease.

BACKGROUND: Respiratory pathogen infections and air pollution are main causes of acute exacerbation of chronic obstructive pulmonary disease (AECOPD). Air pollution has a direct effect on the airway epithelial barrier and the immune system, which can have an influence on infection. However, studies on the relationship between respiratory infections and air pollutants in severe AECOPD are limited. Thus, the objective of this study was to investigate the correlation between air pollution and respiratory pathogen in severe AECOPD. METHODS: This multicenter observational study was conducted by reviewing electronic medical records of patients with AECOPD at 28 hospitals in South Korea. Patients were divided into four groups according to the comprehensive air-quality index (CAI) used in Korea. Identification rates of bacteria and viruses of each group were analyzed. RESULTS: Viral pathogens were identified in 270 (36.7%) of 735 patients. Viral identification rate was different (P = 0.012) according to air pollution. Specifically, the virus detection rate was 55.9% in the group of CAI 'D' with the highest air pollution. It was 24.4% in the group of CAI 'A' with the lowest air pollution. This pattern was clearly seen for influenza virus A (P = 0.042). When further analysis was performed with particulate matter (PM), the higher/lower the PM level, the higher/lower the virus detection rate. However, no significant difference was found in the analysis related to bacteria. CONCLUSION: Air pollution may make COPD patients more susceptible to respiratory viral infections, especially influenza virus A. Thus, on days with poor air quality, COPD patients need to be more careful about respiratory infections.

Impact of Nonpharmacological Interventions on Severe Acute Respiratory Infections in Children: From the National Surveillance Database.

BACKGROUND: Nonpharmacological interventions (NPIs) reduce the incidence of respiratory infections. After NPIs imposed during the coronavirus disease 2019 pandemic ceased, respiratory infections gradually increased worldwide. However, few studies have been conducted on severe respiratory infections requiring hospitalization in pediatric patients. This study compares epidemiological changes in severe respiratory infections during pre-NPI, NPI, and post-NPI periods in order to evaluate the effect of that NPI on severe respiratory infections in children. METHODS: We retrospectively studied data collected at 13 Korean sentinel sites from January 2018 to October 2022 that were lodged in the national Severe Acute Respiratory Infections (SARIs) surveillance database. RESULTS: A total of 9,631 pediatric patients were admitted with SARIs during the pre-NPI period, 579 during the NPI period, and 1,580 during the post-NPI period. During the NPI period, the number of pediatric patients hospitalized with severe respiratory infections decreased dramatically, thus from 72.1 per 1,000 to 6.6 per 1,000. However, after NPIs ceased, the number increased to 22.8 per 1,000. During the post-NPI period, the positive test rate increased to the level noted before the pandemic. CONCLUSION: Strict NPIs including school and daycare center closures effectively reduced severe respiratory infections requiring hospitalization of children. However, childcare was severely compromised. To prepare for future respiratory infections, there is a need to develop a social consensus on NPIs that are appropriate for children.

Prognostic marker for severe acute exacerbation of chronic obstructive pulmonary disease: analysis of diffusing capacity of the lung for carbon monoxide (DLCO) and forced expiratory volume in one second (FEV1).

BACKGROUND: It is important to assess the prognosis of patients with chronic obstructive pulmonary disease (COPD) and acute exacerbation of COPD (AECOPD). Recently, it was suggested that diffusing capacity of the lung for carbon monoxide (DLCO) should be added to multidimensional tools for assessing COPD. This study aimed to compare the DLCO and forced expiratory volume in one second (FEV1) to identify better prognostic factors for admitted patients with AECOPD. METHODS: We retrospectively analyzed 342 patients with AECOPD receiving inpatient treatment. We classified 342 severe AECOPD patients by severity of DLCO and FEV1 (≤ vs. > 50% predicted). We tested the association of FEV1 and DLCO with the following outcomes: in-hospital mortality, need for mechanical ventilation, need for intensive care unit (ICU) care. We analyzed the prognostic factors by multivariate analysis using logistic regression. In addition, we conducted a correlation analysis and receiver operating characteristic (ROC) curve analysis. RESULTS: In multivariate analyses, DLCO was associated with mortality (odds ratio = 4.408; 95% CI 1.070-18.167; P = 0.040) and need for mechanical ventilation (odds ratio = 2.855; 95% CI 1.216-6.704; P = 0.016) and ICU care (odds ratios = 2.685; 95% CI 1.290-5.590; P = 0.008). However, there was no statistically significant difference in mortality rate when using FEV1 classification (P = 0.075). In multivariate linear regression analyses, DLCO (B = - 0.542 ± 0.121, P < 0.001) and FEV1 (B = - 0.106 ± 0.106, P = 0.006) were negatively associated with length of hospital stay. In addition, DLCO showed better predictive ability than FEV1 in ROC curve analysis. The area under the curve (AUC) of DLCO was greater than 0.68 for all prognostic factors, and in contrast, the AUC of FEV1 was less than 0.68. CONCLUSION: DLCO was likely to be as good as or better prognostic marker than FEV1 in severe AECOPD.

Validation of Previous Spirometric Reference Equations and New Equations.

BACKGROUND: Pulmonary functions are interpreted using predicted values from reference equations that vary with ethnicity, gender, age, height, and weight. The universally used Choi's reference equations are not validated for Korean populations, and the purpose of this study was to validate them and develop new reference equations. METHODS: Subjects with normal spirometry and chest radiographs, no co-morbidities, and non-smokers, from the Korean National Health and National Examination Survey (KNHANES)-VI were enrolled (n = 117). Intraclass correlation coefficient (ICC) was assessed for reliability of reference equations. New reference equations were developed using linear regression analysis. Differences between observed and predicted values were assessed to compare the reference equations from Choi's, Global Lung Function Initiative 2012, KNHANES-IV, and newly developed equations. RESULTS: The ICC of Choi's reference equations was 0.854 (P < 0.001). The new reference equations for men were: forced vital capacity (FVC) (L) = - 4.38775 - 0.01184 × age + 0.05547 × height, forced expiratory volume - 1 second (FEV1) (L) = - 2.40147 - 0.02134 × age + 0.04103 × height; and for women: FVC (L) = - 3.09063 + 0.003904 × age + 0.038694 × height; FEV1 (L) = - 1.32933 - 0.00872 × age + 0.02762 × height. The differences between the predicted and observed means were largest in Choi's equations, but lowest in the new equations with highest goodness of fit. CONCLUSION: Because Choi's reference equations presented larger differences from the observed values, despite reliability, and the new reference equations showed better goodness of fit, we suggest the latter for Korean populations.

A Randomized, Placebo-Controlled Phase 2 Trial of CNTO 6785 in Chronic Obstructive Pulmonary Disease.

Interleukin (IL)-17A may be an underlying factor in the pathophysiology of chronic obstructive pulmonary disease (COPD). Anti-IL-17 monoclonal antibodies have been used successfully in treating several immune-mediated inflammatory diseases. This phase 2, randomized, placebo-controlled, double-blind, parallel-group, proof-of-concept study is the first clinical study evaluating the efficacy and safety of the anti-IL-17A monoclonal antibody CNTO 6785 in patients with symptomatic moderate-to-severe COPD. Patients were treated with CNTO 6785 (n = 93) or placebo (n = 94) intravenously at Weeks 0, 2, and 4 (induction), then Weeks 8 and 12, and followed till Week 24. The primary efficacy endpoint was the change from baseline in pre-bronchodilator percent-predicted forced expiratory volume in 1 second at Week 16. Samples were collected at all visits for pharmacokinetic (PK) evaluation, and standard safety assessments were performed. The mean difference in the primary efficacy endpoint between CNTO 6785 and placebo was not statistically significant (-0.49%; p = 0.599). No other efficacy endpoints demonstrated clinically or statistically significant differences with CNTO 6785 compared with placebo. CNTO 6785 was generally well tolerated; no major safety signals were detected. The most frequently reported treatment-emergent adverse events were infections and infestations; however, no notable differences were observed between CNTO 6785 and placebo in terms of rates of infections. PK results suggested that the steady state of serum CNTO 6785 concentration was reached within 16 weeks. These results suggest that IL-17A is unlikely to be a dominant driver in the pathology of, or a viable therapeutic target for, COPD. ClinicalTrials.gov Identifier: NCT01966549; EudraCT Identifier: 2012-003607-36.

Prognostic Factors and Skeletal-Related Events in Patients with Small Cell Lung Cancer with Bone Metastases at the Time of Diagnosis.

BACKGROUND/OBJECTIVE: The aim of this study was to evaluate the characteristics and prognostic factors of small cell lung cancer (SCLC) with bone metastases. We also investigated the characteristics and predictive factors of skeletal-related events (SREs) in these patients. MATERIALS AND METHODS: Sixty-one patients who were first diagnosed with SCLC with bone metastases at our institution were included in this retrospective analysis. RESULTS: The overall survival (OS) of patients with bone metastases was shorter than that of patients without bone metastases (4.13 vs. 6.17 months, p = 0.015). Poor Eastern Cooperative Oncology Group (ECOG) performance status (PS; ≥2) and higher serum alkaline phosphatase (ALP; above upper normal limit × 2) were independent poor prognostic factors (p = 0.027 for ECOG PS, p = 0.002 for ALP). More than 1 SRE occurred in 21 patients (34.4%). Cervical spine metastasis, thoracic spine metastasis, pelvic bone metastasis, more than 5 bone metastatic regions and higher serum lactate dehydrogenase were correlated with the occurrence of SREs. Thoracic spinal metastasis was a strong predictive factor for the occurrence of SREs (odds ratio = 5.475; 95% CI: 1.080-27.755). CONCLUSION: Our study demonstrates the poor prognosis of SCLC patients with bone metastases. Physicians should treat SCLC patients with bone metastases with caution.

The effect of an IκB-kinase-ß(IKKß) inhibitor on tobacco smoke-induced pulmonary inflammation.

PURPOSE OF THE STUDY: Inactivation of NF-κB with IKKß knockout mice reduces tobacco smoke-induced pulmonary inflammation. In this study, we investigated whether the IKKß inhibitor PS-1145 could attenuate the pulmonary inflammation induced by tobacco smoke. MATERIALS AND METHODS: We divided 30 mice into three groups: a control group, a smoking group, and a PS-1145 group. Mice from the smoking and PS-1145 groups were exposed for 2 weeks to tobacco smoke. PS-1145 was injected intraperitoneally before every tobacco smoke exposure. After 2 weeks, bronchoalveolar lavage (BAL) was performed for cell counting and measuring of inflammatory chemokines. We analyzed the correlation between NF-κB and NF-κB-regulated chemokines in BAL fluid and measured the neutrophils and macrophages by immunostaining in lung tissues. RESULTS: The PS-1145 group showed a significant reduction in the number of total cells, neutrophils, and macrophages, as well as the KC and MCP-1 level, in the BAL fluid compared to the smoking group. There was no significant difference in the level of MIP-1α. The level of NF-κB in BAL fluid was significantly positively correlated with KC and MCP-1 levels, but not with MIP-1α level. The PS-1145 group also showed a significant fewer neutrophils and macrophages in the lung tissue. CONCLUSIONS: We conclude that the IKKß inhibitor PS-1145 suppressed the NF-κB signaling pathway and reduced the recruitment of inflammatory cells and chemokines in pulmonary inflammation induced by tobacco smoke. IKKß inhibition offers a potential therapeutic target for tobacco smoke-induced pulmonary inflammation.

Comparison of the Efficacy between Pemetrexed plus Platinum and Non-Pemetrexed plus Platinum as First-Line Treatment in Patients with Wild-Type Epidermal Growth Factor Receptor Nonsquamous Non-Small Cell Lung Cancer: A Retrospective Analysis.

BACKGROUND: Despite the development of molecular research and targeted therapy, patients with wild-type epidermal growth factor receptor (EGFR) non-small cell lung cancer (NSCLC) still receive platinum doublet chemotherapy as the standard first-line treatment. We investigated the efficacy of first-line regimens in patients with wild-type EGFR nonsquamous NSCLC. METHODS: We retrospectively analyzed the efficacy of various platinum doublet regimens as first-line treatments. Between 2007 and 2013, a total of 165 patients with wild-type EGFR nonsquamous NSCLC were included in this study. RESULTS: Seventy-one (43.0%) patients were treated with pemetrexed plus platinum (PP) and 94 (57.0%) with non-pemetrexed plus platinum (NPP). The overall response rate was not different between the PP- and NPP-treated groups (26.8 vs. 28.7%, respectively; p = 0.78). The median progression-free survival (PFS) and overall survival (OS) also showed no differences between the two treatment groups (p = 0.12 for PFS, p = 0.42 for OS). The median PFS and OS for the PP group were 4.6 months (95% CI, 3.8-5.4) and 18.7 months (95% CI, 11.7-25.8), respectively, and for the NPP group, they were 4.2 months (95% CI, 3.4-5.0) and 12.2 months (95% CI, 10.3-14.1), respectively. In the subgroup analysis, most subgroups showed no significant difference in PFS and OS between the two treatment groups. CONCLUSION: Our data showed that the efficacy of various platinum doublet regimens was similar in patients with wild-type EGFR nonsquamous NSCLC.

The effect of adipose stem cell therapy on pulmonary fibrosis induced by repetitive intratracheal bleomycin in mice.

Adipose stem cells (ASCs) are detectable in the parenchyma and large airways of lungs after systemic administration, and ameliorate inflammatory infiltration and cell death in animal models of emphysema. We evaluated whether ASC treatment could attenuate lung fibrosis induced by repetitive intratracheal bleomycin administration. Male 8-week-old C57BL/6J mice (control group, bleomycin-only group, and bleomycin-plus-ASC group) were used. Eight biweekly doses of bleomycin were injected intratracheally via an intubation procedure at a dose of 0.04 units in a total volume of 100 µL of sterile saline. During the latter 2 months of the 4-month bleomycin exposure, human ASCs (3 × 10(5) cells) were administered repeatedly via intraperitoneal injection at the same time as bleomycin. Lung tissues were evaluated for histology, collagen content, TUNEL staining, and TGF-ß levels. Bronchoalveolar lavage (BAL) was performed for cell counting. Administrations of ASCs ameliorated the deleterious effects of repetitive intratracheal instillation of bleomycin, namely hyperplasia of Club cells (Clara cells) and cuboidal alveolar epithelial cells, infiltration of the perialveolar ducts by inflammatory cells, septal thickening, enlarged alveoli, and extensive fibrosis. Addition of ASC led to suppression of bleomycin-induced epithelial cell apoptosis and expression of TGF-ß. These results suggest a useful therapeutic effect of ASCs on pulmonary fibrosis induced by repetitive bleomycin administration. Further studies will be required to evaluate the efficacy of ASC therapy for the treatment of idiopathic pulmonary fibrosis.

Effects of transglutaminase 2 inhibition on ventilator-induced lung injury.

This study was performed to examine the role of transglutaminase 2 (TG2) in ventilator-induced lung injury (VILI). C57BL/6 mice were divided into six experimental groups: 1) control group; 2) lipopolysaccharide (LPS) group; 3) lung protective ventilation (LPV) group; 4) VILI group; 5) VILI with cystamine, a TG2 inhibitor, pretreatment (Cyst+VILI) group; and 6) LPV with cystamine pretreatment (Cyst+LPV) group. Acute lung injury (ALI) score, TG2 activity and gene expression, inflammatory cytokines, and nuclear factor-κB (NF-κB) activity were measured. TG2 activity and gene expression were significantly increased in the VILI group (P < 0.05). Cystamine pretreatment significantly decreased TG2 activity and gene expression in the Cyst+VILI group (P < 0.05). Inflammatory cytokines were higher in the VILI group than in the LPS and LPV groups (P < 0.05), and significantly lower in the Cyst+VILI group than the VILI group (P < 0.05). NF-κB activity was increased in the VILI group compared with the LPS and LPV groups (P < 0.05), and significantly decreased in the Cyst+VILI group compared to the VILI group (P = 0.029). The ALI score of the Cyst+VILI group was lower than the VILI group, but the difference was not statistically significant (P = 0.105). These results suggest potential roles of TG2 in the pathogenesis of VILI.

Rapid Progression of Acute Interstitial Pneumonia in a Patient with Low MDA-5 Antibody Titer.

BACKGROUND Melanoma differentiation associated gene-5 antibody (MDA-5 Ab) is one of the diagnostic autoantibodies that appears in idiopathic inflammatory myopathies (IIMs). Unlike when other autoantibodies are positive, when this antibody is positive, there is less characteristic muscle involvement. However, this MDA-5 Ab-positive myopathy presents extremely rapid progression of interstitial lung disease, resulting in a high mortality rate. Previous studies reported that the prognosis of this lung disease will be determined by the titer and suggest that low titers of MDA-5 antibody can indicate a good prognosis in associated interstitial lung disease. CASE REPORT Our case describes a 55-year-old woman who presented with acute respiratory symptoms and dyspnea. After hospitalization, symptoms and chest imaging worsened rapidly, and the radiology image of lung disease featured interstitial changes not seen in typical infections. We treated the patient with a high-flow oxygen nasal cannula, empirical antibiotics, and a systemic steroid. While treatment for a disease of unknown cause was continued, low titer of MDA-5 antibody was identified. CONCLUSIONS This case suggests 2 points to consider about non-infectious interstitial changes with acute respiratory distress syndrome. First, when treating rapidly progressing interstitial pneumonia of an unknown cause, it is recommended to consider lung involvement of MDA-5 Ab dermatomyositis. Second, a low titer of MDA-5 Ab can be associated with better prognosis in this MDA-5 Ab dermatomyositis-related lung disease.

Mechanical ventilation in patients with idiopathic pulmonary fibrosis in Korea: a nationwide cohort study.

BACKGROUND/AIMS: The prognosis of patients with idiopathic pulmonary fibrosis (IPF) and respiratory failure requiring mechanical ventilation is poor. Therefore, mechanical ventilation is not recommended. Recently, outcomes of mechanical ventilation, including those for patients with IPF, have improved. The aim of this study was to investigate changes in the use of mechanical ventilation in patients with IPF and their outcomes over time. METHODS: This retrospective, observational cohort study used data from the National Health Insurance Service database. Patients diagnosed with IPF between January 2011 and December 2019 who were placed on mechanical ventilation were included. We analyzed changes in the use of mechanical ventilation in patients with IPF and their mortality using the Cochran- Armitage trend test. RESULTS: Between 2011 and 2019, 1,227 patients with IPF were placed on mechanical ventilation. The annual number of patients with IPF with and without mechanical ventilation increased over time. However, the ratio was relatively stable at approximately 3.5%. The overall hospital mortality rate was 69.4%. There was no improvement in annual hospital mortality rate. The overall 30-day mortality rate was 68.7%, which did not change significantly. The overall 90-day mortality rate was 85.3%. The annual 90-day mortality rate was decreased from 90.9% in 2011 to 83.1% in 2019 (p = 0.028). CONCLUSION: Despite improvements in intensive care and ventilator management, the prognosis of patients with IPF receiving mechanical ventilation has not improved significantly.

Economic burden and epidemiology of pneumonia in Korean adults aged over 50 years.

This study was performed to estimate the direct medical costs and epidemiology of pneumonia in adults of Korea. We conducted a multi-center, retrospective, observational study and collected data targeting for community-acquired pneumonia patients ( ≥ 50 yr) from 11 hospitals. Costs attributable to the treatment of pneumonia were estimated by reviewing resource utilization and epidemiology data (distribution of pathogen, hospital length of stay, overall outcome) were also collected. A total 693 patients were included; average 70.1 ( ± 10.5) aged, 57.3% male and average 1.16 CURB-65 (confusion, blood urea nitrogen, respiratory rate, blood pressure, age > 65 yr) scored. The pathogen was identified in the 32.9% (228 patients); Streptococcus pneumoniae accounted for 22.4% (51 patients) of identified pathogens. The hospital mortality was 3.2% (especially, for S. pneumoniae was 5.9%) and average length of stay was 9 days. The mean total cost for the treatment of pneumonia was US dollar (USD) 1,782 (SD: USD 1,501). Compared to the cost of all caused pneumonia, that of pneumococcal pneumonia was higher, USD 2,049 ( ± USD 1,919), but not statistically significant. Charge of hospitalization accounted the greatest part of total medical costs. The economic burden of pneumonia was high in Korea, and the prevention of pneumonia should be considered as effective strategy.

Cardiac Dysfunction Is Not Associated with Increased Reintubation Rate in Patients Treated with Post-extubation High-Flow Nasal Cannula.

BACKGROUND: Cardiac dysfunction patients have long been considered at high risk of reintubation. However, it is based on past studies in which only conventional oxygen therapy was applied after extubation. We investigated association between cardiac dysfunction and reintubation rate in situation where high-flow nasal cannula (HFNC) was widely used during post-extubation period. METHODS: We conducted a retrospective observational cohort study of patients treated with HFNC after planned extubation in medical intensive care unit of single tertiary center. Patients were divided into normal function group (ejection fraction [EF] ≥45%) and cardiac dysfunction group (EF <45%). The primary outcome was reintubation rate within 72 hours following extubation. RESULTS: Of 270 patients, 35 (13%) had cardiac dysfunction. Baseline characteristics were similar in both groups. There were no differences in the changes in vital signs between the two groups during the first 12 hours after extubation except diastolic blood pressure. The reintubation rates were 20% and 17% for cardiac dysfunction group and normal function group, respectively (p=0.637). In a multivariate Cox regression analysis, cardiac dysfunction was not associated with an increased risk of reintubation within 72 hours following extubation (hazard ratio, 1.56; p=0.292). CONCLUSION: Cardiac dysfunction was not associated with increased reintubation rate within 72 hours when HFNC is immediately applied after planned extubation.

The efficacy and safety of DW1601 in patients with acute bronchitis: a multi-center, randomized, double-blind, phase III clinical trial.

BACKGROUND/AIMS: DW1601, an oral fixed dose combination syrup composed of DW16011 and Pelargonium sidoides, was developed to enhance the symptom relief effect in patients with acute bronchitis. We evaluated the efficacy and safety of DW1601 compared to DW16011 or P. sidoides for treatment of acute bronchitis using a randomized, double-blind, placebocontrolled, multi-centre trial design. METHODS: A total of 204 patients with acute bronchitis was randomized 1:1:1 to receive DW1601 (n = 67), DW16011 (n = 70), or P. sidoides (n = 64) for 7 days. The primary outcome was efficacy of DW1601 compared to DW16011 or P. sidoides in reducing the total bronchitis severity score (BSS) at day 4 of treatment. Secondary endpoints were changes in total and symptomspecific BSS, response rate and patient satisfaction rate. Safety analysis was assessed at day 7. RESULTS: At 4 days after medication, decrease of total BSS from baseline was significantly greater in the DW1601 group than in the DW16011 group (-3.51 ± 0.18 vs. -2.65 ± 0.18, p = 0.001) or P. sidoides group (-3.56 ± 0.18 vs. -2.64 ± 0.19, p < 0.001). In addition, the BSS total score at day 7 and the BSS cough and sputum component scores at days 4 and 7 were significantly more improved with DW1601 treatment compared with the DW16011 group or P. sidoides group. Participants treated with DW1601 showed higher rates of response and satisfaction than control groups (response rate, DW1601, 100% vs. DW16011, 85.7% vs. P. sidoides, 85.9%; satisfaction rate, DW1601, 92.6% vs. DW16011, 82.9% vs. P. sidoides, 81.2%). Significant adverse events were not observed in the DW1601 group. CONCLUSION: DW1601 is superior to DW16011 or P. sidoides in improving symptoms of acute bronchitis.

Clinical efficacy of adjuvant chemotherapy in stage IB (< 4 cm) non-small cell lung cancer patients with high-risk factors.

BACKGROUND/AIMS: Adjuvant chemotherapy is the standard of care for resected stage II-IIIA non-small cell lung cancer (NCSLC). The efficacy of adjuvant chemotherapy in stage IB (< 4 cm) NSCLC with high-risk factors is controversial. METHODS: This retrospective multicenter study included 285 stage IB NSCLC patients with high-risk factors according to the 8th edition tumor, node, metastasis (TNM) classification from four academic hospitals. High-risk factors included visceral pleural invasion, vascular invasion, lymphatic invasion, lung neuroendocrine tumors, and micropapillary histology patterns. RESULTS: Of the 285 patients, 127 (44.6%) were included in the adjuvant chemotherapy group and 158 (55.4%) were included in the non-adjuvant chemotherapy group. The median follow-up was 41.5 months. Patients in the adjuvant chemotherapy group had a significantly reduced recurrence rate and risk of mortality than those in the non-adjuvant chemotherapy group (hazards ratio, 0.408; 95% confidence interval, 0.221 to 0.754; p = 0.004 and hazards ratio, 0.176; 95% confidence interval, 0.057 to 0.546; p = 0.003, respectively). Adjuvant chemotherapy should be particularly considered for the high-risk factors such as visceral pleural involvement or vascular invasion. Based on the subgroup analysis, adjuvant chemotherapy should be considered when visceral pleural involvement is present, even if the tumor size is < 3 cm. CONCLUSION: Adjuvant chemotherapy may be useful for patients with stage IB NSCLC with high-risk factors and is more relevant for patients with visceral pleural involvement or vascular invasion.

Nationwide Social Distancing and the Epidemiology of Severe Acute Respiratory Infections.

Nonpharmaceutical interventions (e.g., social distancing) are recommended to prevent the spread of respiratory viruses. However, few epidemiological studies have assessed whether social distancing in actual settings reduces the disease burden of severe acute respiratory infections (SARIs) in the general population. Accordingly, we aimed to assess associations between nationwide social distancing for coronavirus disease 2019 (COVID-19) and non-COVID-19 SARIs. We collected data on SARI epidemiologic characteristics recorded from January 2018 through December 2020 from the nationwide sentinel SARI surveillance data maintained by the Korea Disease Control and Prevention Agency. The number of SARIs per 1000 hospitalized patients decreased significantly to 18.61, 18.15, and 6.25 in 2018, 2019, and 2020 (p<0.001), respectively, during the surveillance period of 3 years. The number of intensive care unit admissions associated with SARIs per 1000 hospitalized patients was 0.83, 0.69, and 0.54 in 2018, 2019, and 2020 (p<0.001), respectively, and the number of SARI-associated mortalities per 1000 patients was 0.42, 0.29, and 0.27 in 2018, 2019, and 2020 (p<0.001), respectively. Moreover, SARIs had two peak seasons in 2 years of the surveillance period (2018 and 2019). However, seasonality was not observed since social distancing was initiated. Our sentinel surveillance data demonstrated a remarkable reduction in SARI disease burden and a change in seasonality following the implementation of nationwide social distancing. Accordingly, we suggest that social distancing could be effective in forthcoming seasonal epidemics of non-COVID19 origin, although the impact thereof on other aspects of society needs to be carefully considered.

Metabolic Fingerprinting Uncovers the Distinction Between the Phenotypes of Tuberculosis Associated COPD and Smoking-Induced COPD.

Background: Although smoking is considered the main cause of chronic obstructive pulmonary disease (COPD), several other risk factors, including pulmonary tuberculosis (TB), contribute significantly to disease causation, particularly in developing countries. However, the underlying pathogenesis of TB-associated COPD (T-COPD) is unclear. Moreover, the need for prompt diagnosis and treatment of T-COPD to decrease the future burden of inflammation is underestimated. This study aimed to identify distinctive endogenous metabotypes of T-COPD, compared to smoking-associated COPD (S-COPD). Methods: Cross-sectional metabolomic analyses and clinical examinations of serum samples were performed for three groups of 168 male subjects: T-COPD (n = 59), S-COPD (n = 70), and healthy normal controls (n = 39). To retain a broad spectrum of metabolites, we performed technically distinct analyses (global metabolomic profiling using LC-QTOFMS and targeted analyses using LC-MS/MS). Results: Higher levels of IL-6 and C-reactive protein and St. George Respiratory Questionnaire scores were seen in the T-COPD group, compared to those in the S-COPD group. Global metabolomic profiling showed elevated metabolites, including arachidonic and eicosanoic acids, in the T-COPD group. Typical changes in tryptophan catabolism were observed through targeted profiling. Additionally, in the T-COPD group, kynurenine was elevated, and serotonin levels were reduced; therefore, indoleamine dioxygenase (IDO)/tryptophan hydroxylase (TPH) activities were dysregulated. Correlation analyses showed that changes in oxylipins were positively correlated with serum levels of IL-6 and C-reactive protein. Conclusion: Patients with TB-related COPD have enhanced inflammatory responses that may be linked to fatty acid pathways and tryptophan catabolism, which could be novel therapeutic targets for T-COPD.