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Abstract Background Ambient humidity has a significant impact on respiratory health and influences disease and symptoms. However, large-scale studies are required to clarify its specific effects on lung function and respiratory symptoms. We examined the relationship between relative humidity (RH), lung function, and respiratory symptoms using data from the Korea National Health and Nutrition Examination Survey (KNHANES). Methods In this cross-sectional study, we analyzed data from KNHANES participants aged ≥ 40 years, collected between 2016 and 2018. Pulmonary function tests (PFTs) and health questionnaires were used to assess lung function and respiratory symptoms. Individual environmental data, including RH, were obtained from the Community Multiscale Air Quality model and linked to the participants’ addresses. Short-term (0–14 days), mid-term (30–180 days), and long-term (1–5 years) RH exposures were examined. Linear regression models were used to evaluate the associations between RH and PFTs. Univariate and multivariable logistic regression models were applied to assess the risk of lung function abnormalities and respiratory symptoms. Results In total, 10,396 participants were included (mean age: 58.3 years, male: 43.6%). In multiple regression analysis, higher RH was negatively associated with the forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) ratio across various time lags, while FVC was positively correlated with long-term RH exposure. In multiple logistic analysis adjusted for clinical and environmental covariates, long-term higher RH exposure was associated with a lower risk of restrictive lung disease (odds ratio [OR] at 4-year moving average [MA]: 0.978, 95% confidence interval [CI]: 0.959–0.997), while mid-term RH exposure decreased the risk of chronic cough (OR at 90-day MA: 0.968, 95% CI: 0.948–0.987) and sputum production (OR at 90-day MA: 0.985, 95% CI: 0.969–1.001). Conclusions Higher RH was negatively associated with lung function and increased the risk of obstructive lung disease, whereas mid-term RH exposure reduced the risk of chronic cough and sputum production.

This study aims to compare and analyze differences and similarities between some Korean and international logistics-related journals. To this end, this study reviewed academic journal articles published between 2007 and 2011 in three international journals. A total of 990 articles were reviewed and categorized in terms of research topics, research methods, and analytical techniques, and subsequently compared. This study is, to the authors’ knowledge, the first attempt to evaluate and compare prestigious international journals and Korean journals in the logistics-related research field similar to studies undertaken in scientific journals. The differences and similarities revealed in this study will help logistics researchers understand the interaction and communication between international and Korean journals, and how they can be used to develop logistics research at both the international and local levels.

Purpose This study examined longitudinal changes in interstitial lung abnormalities (ILAs) and predictors of clinically significant interstitial lung diseases (ILDs) in a screening population with ILAs. Materials and Methods We retrieved 36891 low-dose chest CT records from screenings between January 2003 and May 2021. After identifying 101 patients with ILAs, the clinical findings, spirometry results, and initial and follow-up CT findings, including visual and artificial intelligence-based quantitative analyses, were compared between patients diagnosed with ILD (n = 23, 23%) and those who were not (n = 78, 77%). Logistic regression analysis was used to identify significant parameters for the clinical diagnosis of ILD. Results Twenty-three patients (n = 23, 23%) were subsequently diagnosed with clinically significant ILDs at follow-up (mean, 8.7 years). Subpleural fibrotic ILAs on initial CT and signs of progression on follow-up CT were common in the ILD group (both p < 0.05). Logistic regression analysis revealed that emerging respiratory symptoms (odds ratio [OR], 5.56; 95% confidence interval [CI], 1.28–24.21; p = 0.022) and progression of ILAs at follow-up chest CT (OR, 4.07; 95% CI, 1.00–16.54; p = 0.050) were significant parameters for clinical diagnosis of ILD. Conclusion Clinically significant ILD was subsequently diagnosed in approximately one-quarter of the screened population with ILAs. Emerging respiratory symptoms and progression of ILAs at followup chest CT can be predictors of clinically significant ILDs.

Abstract Inhaled corticosteroids (ICS) are commonly used for airway disease, but concerns about adrenal insufficiency (AI) have arisen. This retrospective observational study investigated the link between ICS use and AI risk using data from the National Health Insurance Service-National Sample Cohort, analyzing 66,631 patients with COPD (Korean Standard Classification of Diseases [KCD] codes J42-J44) or asthma (KCD codes J45-J46). ICS use, daily dosage, and AI cases (hospitalization or ≥ 2 outpatient visits with KCD code E27) were identified via diagnostic codes. Cox proportional hazard survival analysis and inverse probability of treatment weighting (IPTW) addressed baseline differences between ICS and non-ICS users. In total 66,631 patients, the mean age was 57.3 years, 42.6% were male, and 42.2% had a Charlson comorbidity index (CCI) of 2 or higher. Among the patients, 15.5% used ICS, with a mean daily dose of 404.2 µg/day. The incidence of AI was higher in ICS users (1.69 per 1000) than in non-users (0.54 per 1000). ICS use independently increased AI risk (HR: 3.06, 95% CI: 1.82–5.14, p

Background Chronic airway diseases, such as asthma and chronic obstructive pulmonary disease (COPD), are increasingly being treated with inhaled corticosteroid (ICS). However, ICSs carry potential infection risks, particularly nontuberculous mycobacteria (NTM). This study investigated the association between ICS use and NTM infection risk using national insurance data, particularly for individuals with chronic airway diseases. Methods We conducted a nationwide population-based study using data from the National Health Insurance Service-National Sample Cohort in South Korea from 2002 to 2019. The cohort included 57,553 patients diagnosed with COPD or asthma. To assess the risk of NTM infection, we used Cox proportional hazards models and propensity score-based inverse probability of treatment weighting (IPTW) to ensure a balanced analysis of covariates. Results Of the 57,553 patients (mean age 56.0 years, 43.2% male), 16.5% used ICS and 83.5% did not. We identified 63 NTM infection cases, including nine among ICS users and 54 among non-users. Before and after IPTW, ICS use was associated with a higher risk of NTM infection (adjusted hazard ratio [HR], 4.01; 95% confidence interval [CI], 1.48 to 15.58). Higher risks were significant for patients ≥65 years (adjusted HR, 6.40; 95% CI, 1.28 to 31.94), females (adjusted HR, 10.91; 95% CI, 2.24 to 53.20), never-smokers (adjusted HR, 6.31; 95% CI, 1.49 to 26.64), systemic steroid users (adjusted HR, 50.19; 95% CI, 8.07 to 312.19), and those with higher comorbidity scores (adjusted HR, 6.64; 95% CI, 1.19 to 37.03). Conclusion ICS use in patients with chronic airway diseases might increase the risk of NTM infection, particularly in older females, never-smokers, and systemic steroid users.

Background Obstructive sleep apnea (OSA) is a prevalent sleep disorder associated with various health issues. Although some studies have suggested an association between reduced lung function and OSA, this association remains unclear. Our study aimed to explore this relationship using data from a nationally representative population- based survey. Methods We performed an analysis of data from the 2019 Korea National Health and Nutrition Examination Survey. Our study encompassed 3,675 participants aged 40 years and older. Risk of OSA was assessed using the STOP-Bang (Snoring, Tiredness during daytime, Observed apnea, and high blood Pressure-Body mass index, Age, Neck circumference, Gender) questionnaire and lung function tests were performed using a portable spirometer. Logistic regression analysis was applied to identify the risk factors associated with a high-risk of OSA, defined as a STOP-Bang score of ≥3. Results Of 3,675 participants, 600 (16.3%) were classified into high-risk OSA group. Participants in the high-risk OSA group were older, had a higher body mass index, and a higher proportion of males and ever-smokers. They also reported lower lung function and quality of life index in various domains along with increased respiratory symptoms. Univariate logistic regression analysis indicated a significant association between impaired lung function and a high-risk of OSA. However, in the multivariable analysis, only chronic cough (odds ratio [OR], 2.413; 95% confidence interval [CI], 1.383 to 4.213) and sputum production (OR, 1.868; 95% CI, 1.166 to 2.992) remained significantly associated with a high OSA risk. Conclusion Our study suggested that, rather than baseline lung function, chronic cough, and sputum production are more significantly associated with OSA risk.

Backgrounds The management of lung complications, especially fibrosis, after COVID-19 pneumonia, is an important issue in the COVID-19 post-pandemic era. We aimed to investigate risk factors for pulmonary fibrosis development in patients with severe COVID-19 pneumonia.Methods Clinical and radiological data were prospectively collected from 64 patients who required mechanical ventilation due to COVID-19 pneumonia and were enrolled from eight hospitals in South Korea. Fibrotic changes on chest CT were evaluated by visual assessment, and extent of fibrosis (mixed disease score) was measured using automatic quantification system.Results 64 patients were enrolled, and their mean age was 58.2 years (64.1% were males). On chest CT (median interval: 60 days [IQR; 41–78 days] from enrolment), 35 (54.7%) patients showed ≥3 fibrotic lesions. The most frequent fibrotic change was traction bronchiectasis (47 patients, 73.4 %). Median extent of fibrosis measured by automatic quantification was 10.6% (IQR, 3.8–40.7%). In a multivariable Cox proportional hazard model, which included nine variables with a p value of

Abstract Association between body mass index (BMI) and prognosis in patients with idiopathic pulmonary fibrosis (IPF) remains uncertain. We investigated the association between BMI and clinical outcomes in patients with IPF using national health claims data. The study included 11,826 patients with IPF and rare incurable disease exemption codes (mean age: 68.9 years, male: 73.8%) and available BMI data who visited medical institutions between January 2002 and December 2018. Multivariable Cox proportional hazard models were used to evaluate the association of BMI with all-cause mortality and hospitalization. Based on BMI, 3.1%, 32.8%, 27.8%, and 36.4% were classified as underweight, normal, overweight, and obese, respectively. Multivariable analysis showed independent associations of overweight (hazard ratio [HR] 0.856, 95% confidence interval [CI] 0.801–0.916) and underweight (HR 1.538, 95% CI 1.347–1.757) with mortality in patients with IPF. Similarly, overweight (HR 0.887, 95% CI 0.834–0.943) and underweight (HR 1.265, 95% CI 1.104–1.449) were also associated with hospitalization in patients with IPF in the multivariable analysis. Spline HR curve analysis adjusted for all covariates revealed a non-linear relationship between BMI and mortality in patients with IPF. Our data suggest that BMI is associated with clinical outcomes in patients with IPF.

Background Exercise capacity is associated with lung function decline in chronicobstructive pulmonary disease (COPD) patients, but a discrepancy between exercisecapacity and airflow limitation exists. This study aimed to explore factors contributingto this discrepancy in COPD patients. Methods Data for this prospective study were obtained from the Korean COPD SubgroupStudy. The exercise capacity and airflow limitation were assessed using the6-minute walk distance (6-MWD; m) and forced expiratory volume in 1 second (FEV1).Participants were divided into four groups: FEV1 >50%+6-MWD >350, FEV1 >50%+6-MWD ≤350, FEV1 ≤50%+6-MWD >350, and FEV1 ≤50%+6-MWD ≤350 and their clinicalcharacteristics were compared. Results A total of 883 patients (male:female, 822:61; mean age, 68.3±7.97 years) wereenrolled. Among 591 patients with FEV1 >50%, 242 were in the 6-MWD ≤350 group, andamong 292 patients with FEV1 ≤50%, 185 were in the 6-MWD >350 group. The multipleregression analyses revealed that male sex (odds ratio [OR], 8.779; 95% confidence interval[CI], 1.539 to 50.087; p=0.014), current smoking status (OR, 0.355; 95% CI, 0.178to 0.709; p=0.003), and hemoglobin levels (OR, 1.332; 95% CI, 1.077 to 1.648; p=0.008)were significantly associated with discrepancies in exercise capacity and airflow limitationin patients with FEV1 >50%. Meanwhile, in patients with FEV1 ≤50%, diffusioncapacity of carbon monoxide (OR, 0.945; 95% CI, 0.912 to 0.979; p=0.002) was significantlyassociated with discrepancies between exercise capacity and airflow limitation. Conclusion The exercise capacity of COPD patients may be influenced by factors otherthan airflow limitation, so these aspects should be considered when assessing andtreating patients.

Abstract Background Smoking status has been linked to the development of idiopathic pulmonary fibrosis (IPF). However, the effect of smoking on the prognosis of patients with IPF is unclear. We aimed to investigate the association between smoking status and all-cause mortality or hospitalisation by using national health claims data. Methods IPF cases were defined as people who visited medical institutions between January 2002 and December 2018 with IPF and rare incurable disease exempted calculation codes from the National Health Insurance Database. Total 10,182 patients with available data on smoking status were included in this study. Ever-smoking status was assigned to individuals with a history of smoking ≥ 6 pack-years. The multivariable Cox proportional hazard model was used to evaluate the association between smoking status and prognosis. Results In the entire cohort, the mean age was 69.4 years, 73.9% were males, and 45.2% were ever smokers (current smokers: 14.2%; former smokers: 31.0%). Current smokers (hazard ratio [HR]: 0.709; 95% confidence interval [CI]: 0.643–0.782) and former smokers (HR: 0.926; 95% CI: 0.862–0.996) were independently associated with all-cause mortality compared with non-smokers. Current smokers (HR: 0.884; 95% CI: 0.827–0.945) and former smokers (HR: 0.909; 95% CI: 0.862–0.959) were also associated with a reduced risk of all-cause hospitalisation compared with non-smokers. A non-linear association between smoking amount and prognosis was found in a spline HR curve and showed increasing risk below 6 pack-years. Conclusion Ever-smoking status may be associated with favourable clinical outcomes in patients with IPF.

Abstract Interstitial lung abnormalities (ILA), incidental findings on computed tomography scans, have raised concerns due to their association with worse clinical outcomes. Our meta-analysis, which included studies up to April 2023 from PubMed/MEDLINE, Embase, and Cochrane Library, aimed to clarify the impact of ILA on mortality, lung cancer development, and complications from lung cancer treatments. Risk ratios (RR) with 95% confidence intervals (CI) were calculated for outcomes. Analyzing 10 studies on ILA prognosis and 9 on cancer treatment complications, we found that ILA significantly increases the risk of overall mortality (RR 2.62, 95% CI 1.94–3.54; I2 = 90%) and lung cancer development (RR 3.85, 95% CI 2.64–5.62; I2 = 22%). Additionally, cancer patients with ILA had higher risks of grade 2 radiation pneumonitis (RR 2.28, 95% CI 1.71–3.03; I2 = 0%) and immune checkpoint inhibitor-related interstitial lung disease (RR 3.05, 95% CI 1.37–6.77; I2 = 83%) compared with those without ILA. In conclusion, ILA significantly associates with increased mortality, lung cancer risk, and cancer treatment-related complications, highlighting the necessity for vigilant patient management and monitoring.

Background: Lymphangioleiomyomatosis (LAM) is a rare multisystemic disorder characterized by the proliferation of abnormal smooth muscle-like cells. Although serum vascular endothelial growth factor-D (VEGF-D) is currently used as a diagnostic biomarker for LAM, its diagnostic value in Korean patients is unclear. Objectives: To evaluate the diagnostic value of serum VEGF-D for LAM in Korean patients. Design: A multicenter prospective cohort study Methods: Serum samples were prospectively collected from five medical institutions, from patients with LAM ( n = 40) and controls ( n = 24; healthy participants = 3, other cystic lung diseases = 13, idiopathic pulmonary fibrosis = 4, idiopathic nonspecific interstitial pneumonia = 4). Serum VEGF-D levels were measured using the enzyme-linked immunosorbent assay, and the diagnostic value was evaluated using receiver operating characteristic (ROC) curve analysis. Results: The mean age of patients with LAM was 44.5 years, and all were female (controls: 47.8 years; female: 70.8%, p

Background Idiopathic pulmonary fibrosis (IPF) is a chronic progressive fibrosing interstitial lung disease with a poor prognosis. While there is evidence suggesting that outdoor air pollution affects the clinical course of IPF, the impact of indoor air pollution on patients with IPF has not been extensively studied. Therefore, this prospective multicentre observational study aims to investigate the association between indoor air pollution and clinical outcomes in patients with IPF.Methods and analysis This study enrolled 140 patients with IPF from 12 medical institutes in the Seoul and Metropolitan areas of the Republic of Korea. Over the course of 1 year, participants visited the institutes every 3 months, during which their clinical data and blood samples were collected. Additionally, indoor exposure to particulate matter ≤2.5 µm (PM2.5) was measured using MicroPEM (RTI International, Research Triangle Park, North Carolina, USA) in each participant’s house for 5 days every 3 months. Lung function was assessed using both site spirometry at each institution and portable spirometry at each participant’s house every 3 months. The study will analyse the impact of indoor PM2.5 on clinical outcomes, including mortality, acute exacerbation, changes in lung function and health-related quality of life, in the participants. This study represents the first attempt to evaluate the influence of indoor air pollution on the prognosis of patients with IPF.Ethics and dissemination This study has received approval from the institutional review board of all participating institutions, including Asan Medical Center, Seoul, Republic of Korea (2021-0072).Trial registration number KCT0006217.

Abstract Background Respiratory diseases contribute to global morbidity and mortality, and temperature is a significant factor. We investigated the association between ambient temperature and emergency department (ED) visits for various respiratory diseases in Seoul, South Korea. Methods Using data from the National Emergency Department Information System (2008–2017), we analysed 1,616,644 ED visits for respiratory diseases, categorised according to the Korean Standard Classification of Diseases 7th revision codes (J00-J99). Using a time-stratified case-crossover design and a distributed lag nonlinear model, we investigated the effect of temperature exposure on ED visits for respiratory diseases, calculating the relative risk (RR) for the maximum risk temperature (MaxRT) of both cold and hot extremes compared to the minimum risk temperature (MinRT). Results Cold temperatures (MaxRT: -9.0 °C) resulted in a 2.68-fold increase (RR = 2.68, 95% CI = 2.26–3.14) in ED visits for total respiratory diseases, while hot temperatures (MaxRT: 29.4 °C) led to a 1.26-fold increase (RR = 1.26, 95% CI = 1.11–1.42) compared to the MinRT (24.8 °C). Cold temperatures increased the risk of most respiratory diseases, except interstitial lung disease, whereas hot temperatures increased ED visits for acute upper respiratory infections and influenza. Cold temperatures increased ED visits for all age groups, especially those aged 18–64 (RR = 3.54, 95% CI = 2.90–4.33), while hot temperatures significantly affected those

Objectives The effect of air pollution on the prognosis of rheumatoid arthritis-associated interstitial lung disease (RA-ILD) remains poorly understood. We aimed to evaluate the effect of long-term exposure to particulate matter with an aerodynamic diameter of ≤10 µm (PM10) and nitrogen dioxide (NO2) on mortality in patients with RA-ILD.Methods We included 309 patients (mean age, 61.7 years; male, 44.3%) with RA-ILD. Individual-level long-term exposures to PM10 and NO2 at their residential addresses were estimated using a national-scale exposure prediction model. The effect of the two air pollutants on mortality was estimated using a Cox-proportional hazards model adjusted for individual-level and area-level characteristics.Results The median follow-up period was 4.8 years, and 40.8% of patients died or underwent lung transplantation. The annual average concentrations of PM10 and NO2 were 56.3 μg/m3 and 22.4 ppb, respectively. When air pollutant levels were stratified by quartiles, no association was observed between air pollutant concentration and mortality in patients with RA-ILD. However, when stratified by two groups (high exposure (top 25th percentile) vs low exposure (bottom 75th percentile)), we observed a significant association between high PM10 exposure and mortality (HR 1.68; 95% CI 1.11 to 2.52; p=0.013) but no association between NO2 exposure and mortality. In the subgroup analyses, the effect of high PM10 exposure on mortality was significant in patients aged

Abstract Background Acute exacerbation (AE) is the most lethal postoperative complication in idiopathic pulmonary fibrosis (IPF); however, prediction before surgery is difficult. We investigated the role of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in predicting postoperative AE in IPF. Method Clinical data of 48 IPF patients who underwent 18F-FDG PET/CT before thoracic surgery were retrospectively analyzed. Mean and maximal standardized uptake values (SUVmean and SUVmax, respectively) were measured in the fibrotic area. Additionally, adjusted values-SUV ratio (SUVR, defined as SUVmax-to-liver SUVmean ratio), tissue fraction-corrected SUVmean (SUVmeanTF), and SUVR (SUVRTF)-were calculated. Results The mean age of the subjects was 67.8 years and 91.7% were male. After thoracic surgery, 21 (43.8%) patients experienced postoperative complications including prolonged air leakage (29.2%), death (14.6%), and AE (12.5%) within 30 days. Patients who experienced AE showed higher SUVmax, SUVR, SUVmeanTF, and SUVRTF than those who did not, but other clinical parameters were not different between patients with and without AE. The SUV parameters did not differ for other complications. The SUVR (odds ratio [OR] 29.262; P = 0.030), SUVmeanTF (OR 3.709; P = 0.041) and SUVRTF (OR 20.592; P = 0.017) were significant predicting factors for postoperative AE following a multivariate logistic regression analysis. On receiver operating characteristics curve analysis, SUVRTF had the largest area under the curve (0.806, P = 0.007) for predicting postoperative AE among SUV parameters. Conclusions Our findings suggest that 18F-FDG PET/CT may be useful in predicting postoperative AE in IPF patients and among SUVs, SUVRTF is the best parameter for predicting postoperative AE in IPF patients.

Abstract Background Radial endobronchial ultrasound (R‐EBUS) transbronchial lung biopsy (TBLB) improves the diagnostic yield from peripheral pulmonary lesions (PPLs). However, the small specimens obtained using small forceps through a guide sheath (GS) may impede diagnosis and molecular analysis. Here, we investigated the diagnostic significance of additional conventional TBLB with standard forceps after R‐EBUS‐GS‐guided TBLB. Methods We retrospectively reviewed data from 55 patients who underwent conventional TBLB after R‐EBUS‐GS‐guided TBLB for PPL diagnosis. Procedures were performed on single PPLs with no visible lesions on bronchoscopy. In cases with inconclusive pathologic confirmation, final diagnoses were made based on pathologic specimens or clinical observations. Results The median size of the target lesions was 28 mm. The appearances on computed tomography images were solid (n = 45, 81.8%), part‐solid (n = 7, 12.7%), and cavitary nodules (n = 3, 5.5%). A computed tomography bronchus sign was present in 35 (63.6%) cases, and a radial probe was positioned within target lesion in 32 (58.2%) cases. R‐EBUS‐GS‐guided TBLB was diagnostic in 30 (54.5%) patients, and subsequent conventional TBLB yielded additional diagnostic information in 8 (14.5%) patients. Probe positioning within target lesions and the outer margin of PPLs more than 1 cm from pleura were significantly associated with enhanced diagnostic yield from the combined procedures. In conventional TBLB, probe positioning within target lesions (75.0% vs. 11.8%, P = 0.004) and characteristic of nonsolid nodules (83.3% vs. 15.8%, P = 0.006) were significantly associated with additional diagnostic utility. Conclusions Conventional TBLB following R‐EBUS‐GS‐guided TBLB could be a useful procedure for diagnosing PPLs, especially for nonsolid nodules. Key points Significant findings of the study: Additional conventional TBLB with standard forceps after R‐EBUS‐GS‐guided TBLB yielded an additional 14.5% diagnostic utility for peripheral pulmonary lesions. For conventional TBLB, probe positioning within target lesions and nonsolid nodules were significantly associated with additional diagnostic utility. What this study adds: Conventional TBLB with standard forceps after R‐EBUS‐GS‐guided TBLB is an effective and economically accessible diagnostic tool for peripheral pulmonary lesions.

Background: Several studies using bronchoalveolar lavage fluid (BALF) reported that lung microbial communities were associated with the development and clinical outcome of idiopathic pulmonary fibrosis (IPF). However, the microbial communities in IPF lung tissues are not well known. This study is aimed to investigate bacterial microbial communities in lung tissues and determine their impact on the clinical outcomes of patients with IPF.Methods: Genomic DNA extracted from lung tissues of patients with IPF (n = 20; 10 non-survivors) and age- and sex-matched controls (n = 20) was amplified using fusion primers targeting the V3 and V4 regions of the 16S RNA genes with indexing barcodes.Results: Mean age of IPF subjects was 63.3 yr, and 65% were male. Alpha diversity indices did not significantly differ between IPF patients and controls, or between IPF non-survivors and survivors. The relative abundance of Lactobacillus, Paracoccus, and Akkermansia was increased, whereas that of Caulobacter, Azonexus, and Undibacterium decreased in patients with IPF compared with that in the controls. A decreased relative abundance of Pelomonas (odds ratio [OR], 0.352, p = 0.027) and Azonexus (OR, 0.013, p = 0.046) was associated with a diagnosis of IPF in the multivariable logistic analysis adjusted by age and gender. Multivariable Cox analysis adjusted for age and forced vital capacity (FVC) revealed that higher relative abundance of Streptococcus (hazard ratio [HR], 1.993, p = 0.044), Sphingomonas (HR, 57.590, p = 0.024), and Clostridium (HR, 37.189, p = 0.038) was independently associated with IPF mortality. The relative abundance of Curvibacter (r = 0.590) and Thioprofundum (r = 0.373) was correlated positively, whereas that of Anoxybacillus (r = −0.509) and Enterococcus (r = −0.593) was correlated inversely with FVC. In addition, the relative abundance of the Aquabacterium (r = 0.616) and Peptoniphilus (r = 0.606) genera was positively correlated, whereas that of the Fusobacterium (r = −0.464) and Phycicoccus (r = −0.495) genera was inversely correlated with distance during the 6-min walking test.Conclusions: The composition of the microbiome in lung tissues differed between patients with IPF and controls and was associated with the diagnosis, mortality, and disease severity of IPF.

Background The detection rate of ground‐glass nodules (GGNs) in the lung has increased with the increased use of low‐dose computed tomography (CT) of the chest for cancer screening; however, limited data is available on the natural history, follow‐up, and treatment of GGNs. The aim of this study was to identify factors associated with an increase in the size of GGNs. Methods A total of 338 patients (mean ages, 59.8 years; males, 35.5%) with 689 nodules who underwent chest CT at our institute between June 2004 and February 2014 were included in this study. The cut‐off date of follow‐up was August 2018. We analyzed the size, solidity, number, and margins of the nodules compared with their appearance on previous chest CT images. The Cox proportional hazard model was used to identify risk factors associated with nodule growth. Results The median follow‐up period was 21.8 months. Of the 338 patients, 38.5% had a history of malignancy, including lung cancer (8.9%). Among the 689 nodules, the median size of the lesions was 6.0 mm (IQR, 5–8 mm), and the proportion of nodules with size ≥10 mm and multiplicity was 17.1% and 66.3%, respectively. Compared to the nodules without an increase in size, the 79 nodules with an increase in size during the follow‐up period were initially larger (growth group, 7.0 mm vs. non‐growth group, 6.0 mm; P = 0.027), more likely to have a size ≥10 mm (26.6% vs. 15.9%; P = 0.018), and had less frequent multiplicity (54.4% vs. 67.9%, P = 0.028). In the multivariate analysis, nodule size ≥10 mm (hazard ratio [HR], 2.044; P = 0.005), a patient history of lung cancer (HR: 2.190, P = 0.006), and solitary nodule (HR: 2.499, P < 0.001) were independent risk factors for nodule growth. Conclusion Careful follow‐up of GGNs is warranted in patients with a history of malignancy, a large , or a solitary nodule.

Abstract Background Lymphangioleiomyomatosis is a rare disease caused by unregulated activation of mammalian target of rapamycin (mTOR) signalling pathway. Sirolimus showed efficacy in a phase 3 trial of patients with lymphangioleiomyomatosis, but the optimal dose remains unclear. Methods We investigated the efficacy and safety of low-dose compared with conventional-dose sirolimus. Clinical data of 39 patients with lymphangioleiomyomatosis (mean age, 34.8 years; median treatment period, 29.6 months) who received sirolimus were retrospectively reviewed. Low-dose sirolimus was defined as any dose that maintained mean blood trough levels lower than those maintained with conventional doses (5–15 ng/mL). Results Fifty-one percent of patients received low-dose therapy. The rate of decline in lung function decreased after treatment in the whole group (forced expiratory volume in 1 s [FEV1], − 0.12 ± 0.47 [before] vs. 0.24 ± 0.48% predicted/month [after], p = 0.027; diffusing capacity for carbon monoxide [DLco], − 0.33 ± 0.61 vs. 0.03 ± 0.26% predicted/month, p = 0.006) compared with before treatment. In the low-dose group, the rate of decline in FEV1 (− 0.08 ± 0.38 [before] vs. 0.19 ± 0.51% predicted/month [after], p = 0.264) and DLco (-0.13 ± 0.62 vs. 0.02 ± 0.28% predicted/month, p = 0.679) showed a numeric trend towards improvement after treatment; however, the conventional-dose group showed significant improvement in FEV1 (− 0.26 ± 0.54 [before] vs. 0.22 ± 0.38 [after] % predicted/month, p = 0.024) and DLco (− 0.55 ± 0.58 vs. 0.04 ± 0.25% predicted/month, p = 0.002) after treatment. Adverse events (AEs) occurred in 89.7% of patients and the most common AEs was hypercholesterolaemia (43.6%), followed by stomatitis (35.9%). The occurrences of AE were similar between the low- and conventional-dose groups (85.0% vs. 94.7%, p = 0.605). Conclusions Low-dose sirolimus may stabilise lung function decline in lymphangioleiomyomatosis patients, but its efficacy appears to be inferior to that of conventional-dose sirolimus.

Abstract Background The prevalence and incidence of sarcoidosis varies worldwide. We estimated the prevalence and incidence of sarcoidosis in Korea using nationwide claims data from the Korean Health Insurance Review and Assessment Service. Methods Cases of sarcoidosis were identified for any visit between 2007 to 2016 that listed the Korean Classification of Disease, 7th edition code of sarcoidosis and rare incurable disease exempted calculation code. A narrow case definition was used as follows: 1) ≥ two sarcoidosis-coded visits within 1 year of the first claim, 2) no claims for other diseases that could form granuloma. Results A total of 4791 patients (narrow, n = 2388) visited medical institutions for sarcoidosis during the study period; 2999 patients (narrow, n = 1696) were newly identified between 2009 and 2015. The sarcoidosis prevalence was 9.37 per 105 people (narrow, 4.69) and was highest between ages 60–69 years. The incidence rate was 0.85 per 105 population at risk (narrow, 0.48), with the highest incidence rate between ages 50–59 years. For incident cases (mean age: 48.5 year), the age distribution in whole population and females showed monophasic patterns peaking at aged 50–59 years, while males had biphasic incidence peak at aged 30–39 years and 60–69 years. The annual incidence rates showed increasing trends from 0.85 per 105 population at risk in 2009 to 0.97 per 105 population at risk in 2015. Conclusions In comparison with previous reports, the prevalence and incidence of sarcoidosis in Korea have increased and middle-aged women showed the highest risk.

Adenocarcinoma is the most common type of non-small cell lung cancer. Some causative genomic alterations in epidermal growth factor receptor (EGFR), including deletions in exon 19 (E19 dels) and a point mutation in E21, are known to have favourable prognoses due to sensitivity to tyrosine kinase inhibitors; however, the prognoses of other uncommon mutations are unclear. This study analysed the clinical significance of EGFR mutation types in lung adenocarcinoma. We retrospectively reviewed 1,020 subjects (mean age: 66.8 years, female: 41.7%) who were diagnosed with advanced lung adenocarcinoma, had EGFR mutation data, and did not undergo surgery from five medical institutes between 2010 and 2016. Subjects were classified according to EGFR mutation status, particularly for exon-specific mutations. EGFR positivity was defined as the presence of mutation and EGFR negativity was defined as wild-type EGFR. EGFR positivity was 38.0%, with the incidence of mutations in E18, E19, E20, and E21 was 3.6%, 51.0%, 3.4%, and 42.0%, respectively. The EGFR positive group survived significantly longer than the negative group (p