Background: Global Lung Function Initiative (GLI)-2012 reference equation is currently suggested for interpretation of spirometry results and a new local reference equation has been developed in South Korea. However, lung function profiles according to the different reference equations and their clinical relevance have not been identified in chronic obstructive pulmonary disease (COPD) patients. Methods: Our cross-sectional study evaluated Choi’s, Korean National Health and National Examination Survey (KNHANES)-VI, and GLI-2012 reference equations. We estimated the percentages of predictive forced expiratory volume in one second (FEV 1) and airflow limitation severity according to reference equations and analyzed their associations with patient reported outcomes (PROs): COPD assessment test (CAT) score, St. George's Respiratory Questionnaire for COPD patients (SGRQ-C) score, and six minute walk distance (6MWD). Results: In the eligible 2,180 COPD patients, lower predicted values of FEV 1 and forced vital capacity (FVC) were found in GLI-2012 compared to Choi's and KNHANES-VI equations.GLI-2012 equation resulted in a lower proportion of patients being classified as FEV 1 < 80% or FVC < 80% compared to the other equations. However, the Z-scores of FEV 1 and FVC were similar between the KNHANES-VI and GLI-2012 equations. Three reference equations exhibited significant associations between FEV 1 (%) and patient-reported outcomes (CAT score, SGRQ-C score, and 6MWD). Conclusion GLI-2012 reference equation may not accurately reflect FEV 1 (%) in the Korean population, but the Z-score using GLI-2012 equation can be a viable option for assessing FEV 1 and airflow limitation in COPD patients. Similar to the other two equations, the GLI-2012 equation demonstrated significant associations with PROs.

Background: Exhaled condensates contain inflammatory biomarkers; however, their roles in the clinical field have been under-investigated. Methods: We prospectively enrolled subjects admitted to pulmonology clinics. We collected exhaled breath condensates (EBC) and analysed the levels of six and 12 biomarkers using conventional and multiplex enzyme-linked immunosorbent assay, respectively. Results: Among the 123 subjects, healthy controls constituted the largest group (81 participants; 65.9%), followed by the preserved ratio impaired spirometry group (21 patients; 17.1%) and the chronic obstructive pulmonary disease (COPD) group (21 patients; 17.1%). In COPD patients, platelet derived growth factor-AA exhibited strong positive correlations with COPD assessment test (ρ=0.5926, p=0.0423) and COPD-specific version of St. George’s Respiratory Questionnaire (SGRQ-C) score (total, ρ=0.6725, p=0.0166; activity, ρ=0.7176, p=0.0086; and impacts, ρ=0.6151, p=0.0333). Granzyme B showed strong positive correlations with SGRQ-C score (symptoms, ρ=0.6078, p=0.0360; and impacts, ρ=0.6007, p=0.0389). Interleukin 6 exhibited a strong positive correlation with SGRQ-C score (activity, ρ=0.4671, p=0.0378). The absolute serum eosinophil and basophil counts showed positive correlations with pro-collagen I alpha 1 (ρ=0.6735, p=0.0164 and ρ=0.6295, p=0.0283, respectively). In healthy subjects, forced expiratory volume in 1 second (FEV1)/forced vital capacity demonstrated significant correlation with CC chemokine ligand 3 (CCL3)/macrophage inflammatory protein 1 alpha (ρ=0.3897 and p=0.0068). FEV1 exhibited significant correlation with CCL11/eotaxin (ρ=0.4445 and p=0.0017). Conclusion Inflammatory biomarkers in EBC might be useful to predict quality of life concerning respiratory symptoms and serologic markers. Further studies are needed.

Long-acting  2 -agonist (LABA)/long-acting muscarinic-antagonist (LAMA) dual therapy has been found to be more effective than LAMA monotherapy in the treatment of chronic obstructive pulmonary disease (COPD). However, among patients with group B or D COPD, the characteristics of patients for whom LABA/LAMA dual therapy is superior to LAMA monotherapy in minimizing acute exacerbations remain unknown.With data from a prospective COPD cohort, subgroup analyses were conducted to determine whether LABA/LAMA dual therapy was superior to LAMA monotherapy in reducing the rate of acute exacerbations in group B and D COPD patients. Group B and D COPD patients taking LAMA or LABA/LAMA were enrolled according to the 2022 Global initiative for Chronic Obstructive Pulmonary Disease guidelines. A total of 737 patients were included in this study: 600 with group B COPD and 137 with group D COPD. Compared with patients taking LAMA monotherapy, those taking LABA/ LAMA had a significantly lower incidence of acute exacerbations over 1 year. In the subgroup of patients ≥70 years old, there was a significantly lower risk of severe COPD exacerbations among group B patients taking LABA/LAMA than among those taking LAMA monotherapy (odds ratio [OR], 0.258; 95% confidence interval [CI], 0.095– 0.703). In contrast, in the subgroup of group D patients with COPD Assessment Test scores ≥25, compared with LAMA monotherapy, LABA/LAMA treatment was associated with lower risk of severe COPD exacerbations (OR, 0.115; 95% CI, 0.018-0.749).The combination of LABA and LAMA was found to be superior to LAMA monotherapy, especially for treating older adults with group B COPD, as well as for group D patients with severe symptoms.

Background/Aims: Pulmonary toxicities of coronavirus disease 2019 (COVID-19) vaccination are exceedingly rare. However, there are a few reported cases after mRNA vaccination, especially from Asian countries. The purpose of this study was to report the clinical characteristics of patients with COVID-19 vaccine-related pneumonitis (CV-P) and to review cases reported in the literature. Methods: We performed a prospective, observational case series analysis. Results: Eleven patients with a median age of 80 years were enrolled. Ten patients developed CV-P after BNT162b2-mRNA vaccination and one after ChAdOx1 nCoV-19 vaccination. We identified various patterns of CV-P, including transient infiltration, life-threatening acute respiratory distress syndrome, and aggravation of underlying interstitial lung disease. Most patients showed favorable outcomes with good responses to corticosteroid therapy. Conclusions Identifying the mechanism of CV-P requires further investigation; however, radiological and laboratory findings in our case series support inflammatory dysregulation in the lung parenchyma after vaccination. Clinicians should consider CV-P in patients with atypical lung infiltration, no specific etiologies, and recent COVID-19 vaccination

Background/Aims: Postbronchodilator forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) less than 0.7 using spirometry is the golden standard to diagnose airf low limitation of chronic obstructive pulmonary disease (COPD). Recently, measuring FEV6 has been suggested as an alternative to measure FVC. Studies about the cut-off value for FEV1/FEV6 to diagnose airflow limitation have shown variable results, with values between 0.7 and 0.8. The purpose of this study was to determine the best cut-off value of FEV1/FEV6 to detect airflow limitation using handheld spirometry. Methods: We recruited subjects over 40 years of age with smoking history over 10 pack-years. Participants underwent measurements with both handheld spirometry and conventional spirometry. We calculated the sensitivity and specificity of the value of FEV1/FEV6 using receiver-operating characteristic (ROC) curve analysis to obtain the diagnostic accuracy of handheld spirometry to detect airflow limitation. Results: A total of 290 subjects were enrolled. Their mean age and smoking amount were 63.1 years and 31.6 pack-years, respectively. According to our ROC curve analysis, when FEV1/FEV6 ratio was 73%, sensitivity and specificity were the maximum and the area under the ROC curve was 0.93, showing an excellent diagnostic accuracy. Sensitivity, specificity, positive predictive value, and negative predictive value were 86.7%, 89.7%, 88.0%, and 88.5%, respectively. Participants with FEV1/FEV6 ≤ 73% had lower FEV1 predicted value compared to those with FEV1/FEV6 > 73% (65.4% vs. 86.5%, p < 0.001). Conclusions In summary, we demonstrate that the value of 73% in FEV1/FEV6 using handheld spirometry has the best sensitivity and specificity to detect airflow limitation in subjects with risk of COPD.

Background/Aims: Studies on the effectiveness of public health measures to prevent respiratory virus transmission in real-world settings are lacking. We investigated the effectiveness of universal mask use and adherence to other personal preventive measures on the changing viral respiratory infection patterns during the coronavirus disease 2019 (COVID-19) pandemic. Methods: Data were extracted from the South Korean National Respiratory Virus Sentinel Surveillance System. During the COVID-19 pandemic, a cross-sectional survey on adherence to personal preventive measures was conducted. Additionally, the number of subway passengers was analyzed to estimate physical distancing compliance. Results: During the pandemic, adherence to personal preventive measures significantly increased, particularly indoors and on public transportation. Respiratory virus trends were compared based on laboratory surveillance data of 47,675 patients with acute respiratory infections (2016 to 2020). The 2019 to 2020 influenza epidemic ended within 3 weeks, from the epidemic peak to the epidemic end, quickly ending the inf luenza season; with a 1.8- to 2.5-fold faster decline than in previous seasons. Previously, the overall respiratory virus positivity rate remained high after the influenza seasons had ended (47.7% to 69.9%). During the COVID-19 pandemic, this positive rate, 26.5%, was significantly lower than those in previous years. Hospital-based surveillance showed a decreased number of hospitalized patients with acute viral respiratory illnesses. Conclusions This study suggests that high compliance to the use of personal preventive measures in public might reduce the incidence of all respiratory virus infections and its hospitalization rates, with no additional quarantine, isolation, or contact screening.

Background: Many chronic obstructive pulmonary disease (COPD) patients receiving monotherapy continue to experience symptoms, exacerbations and poor quality of life. This study aimed to assess the efficacy and safety of direct switch from once-daily tiotropium (TIO) 18 μg to indacaterol/glycopyrronium (IND/GLY) 110/50 μg once-daily in COPD patients in Korea. Methods: This was a randomized, open-label, parallel group, 12-week trial in mild-to-moderate COPD patients who received TIO 18 μg once-daily for ≥12 weeks prior to study initiation. Patients aged ≥40 years, with predicted postbronchodilator forced expiratory volume in 1 second (FEV1) ≥50%, post-bronchodilator FEV1/forced vital capacity <0.7 and smoking history of ≥10 pack-years were included. Eligible patients were randomized in a 1:1 ratio to either IND/GLY or TIO. The primary objective was to demonstrate superiority of IND/GLY over TIO in pre-dose trough FEV1 at week 12. Secondary endpoints included transition dyspnea index (TDI) focal score, COPD assessment test (CAT) total score, and rescue medication use following the 12-week treatment, and safety assessment. Results: Of the 442 patients screened, 379 were randomized and 347 completed the study. IND/GLY demonstrated superiority in pre-dose trough FEV1 versus TIO at week 12 (least squares mean treatment difference [Δ], 50 mL; p=0.013). Also, numerical improvements were observed with IND/GLY in the TDI focal score (Δ, 0.31), CAT total score (Δ, –0.81), and rescue medication use (Δ, –0.09 puffs/day). Both treatments were well tolerated by patients. Conclusion A direct switch from TIO to IND/GLY provided improvements in lung function and other patient-reported outcomes with an acceptable safety profile in patients with mild-to-moderate airflow limitation.

Background/Aims: Postbronchodilator forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) less than 0.7 using spirometry is the golden standard to diagnose airf low limitation of chronic obstructive pulmonary disease (COPD). Recently, measuring FEV6 has been suggested as an alternative to measure FVC. Studies about the cut-off value for FEV1/FEV6 to diagnose airflow limitation have shown variable results, with values between 0.7 and 0.8. The purpose of this study was to determine the best cut-off value of FEV1/FEV6 to detect airflow limitation using handheld spirometry. Methods: We recruited subjects over 40 years of age with smoking history over 10 pack-years. Participants underwent measurements with both handheld spirometry and conventional spirometry. We calculated the sensitivity and specificity of the value of FEV1/FEV6 using receiver-operating characteristic (ROC) curve analysis to obtain the diagnostic accuracy of handheld spirometry to detect airflow limitation. Results: A total of 290 subjects were enrolled. Their mean age and smoking amount were 63.1 years and 31.6 pack-years, respectively. According to our ROC curve analysis, when FEV1/FEV6 ratio was 73%, sensitivity and specificity were the maximum and the area under the ROC curve was 0.93, showing an excellent diagnostic accuracy. Sensitivity, specificity, positive predictive value, and negative predictive value were 86.7%, 89.7%, 88.0%, and 88.5%, respectively. Participants with FEV1/FEV6 ≤ 73% had lower FEV1 predicted value compared to those with FEV1/FEV6 > 73% (65.4% vs. 86.5%, p < 0.001). Conclusions In summary, we demonstrate that the value of 73% in FEV1/FEV6 using handheld spirometry has the best sensitivity and specificity to detect airflow limitation in subjects with risk of COPD.

Background/Aims: Studies on the effectiveness of public health measures to prevent respiratory virus transmission in real-world settings are lacking. We investigated the effectiveness of universal mask use and adherence to other personal preventive measures on the changing viral respiratory infection patterns during the coronavirus disease 2019 (COVID-19) pandemic. Methods: Data were extracted from the South Korean National Respiratory Virus Sentinel Surveillance System. During the COVID-19 pandemic, a cross-sectional survey on adherence to personal preventive measures was conducted. Additionally, the number of subway passengers was analyzed to estimate physical distancing compliance. Results: During the pandemic, adherence to personal preventive measures significantly increased, particularly indoors and on public transportation. Respiratory virus trends were compared based on laboratory surveillance data of 47,675 patients with acute respiratory infections (2016 to 2020). The 2019 to 2020 influenza epidemic ended within 3 weeks, from the epidemic peak to the epidemic end, quickly ending the inf luenza season; with a 1.8- to 2.5-fold faster decline than in previous seasons. Previously, the overall respiratory virus positivity rate remained high after the influenza seasons had ended (47.7% to 69.9%). During the COVID-19 pandemic, this positive rate, 26.5%, was significantly lower than those in previous years. Hospital-based surveillance showed a decreased number of hospitalized patients with acute viral respiratory illnesses. Conclusions This study suggests that high compliance to the use of personal preventive measures in public might reduce the incidence of all respiratory virus infections and its hospitalization rates, with no additional quarantine, isolation, or contact screening.

Adrenal Cortex Hormones ; Asthma ; Eosinophils ; Humans ; Inflammation ; Nebulizers and Vaporizers ; Nitric Oxide ; Odds Ratio ; Prescriptions ; Pulmonary Disease, Chronic Obstructive ; Respiratory Sounds