Timing and predictors of death during treatment in patients with multidrug/rifampin-resistant tuberculosis in South Korea.

Background/Aims: This study aimed to investigate the timing and predictors of death during treatment among patients with multidrug/rifampin-resistant tuberculosis (MDR/RR-TB) in South Korea. Methods: This was a retrospective cohort study that included MDR/RR-TB cases notified between 2011 and 2017 in South Korea. Results: Among 7,226 MDR/RR-TB cases, 699 (9.7%) died at a median of 167 days (IQR 51-358 d) from the initiation of MDR-TB treatment. The cumulative proportion of all-cause death was 35.5% at 90 days and 52.8% at 180 days from treatment initiation. TB-related deaths occurred at a median of 133 days (IQR 32-366 d), which was significantly earlier than the median of 184 days (IQR 68-356 d) for non-TB-related deaths (p = 0.002). In a multivariate analysis, older age was the factor most strongly associated with death, with those aged ≥ 75 years being 68 times more likely to die (aHR 68.11, 95% CI 21.75-213.26), compared those aged ≤ 24 years. In addition, male sex, comorbidities (cancer, human immunodeficiency virus, and end stage renal disease), the lowest household income class, and TB-specific factors (previous history of TB treatment, smear positivity, and fluoroquinolone resistance) were identified as independent predictors of all-cause death. Conclusions: This nationwide study highlights increased deaths during the intensive phase and identifies high-risk groups including older people and those with comorbidities or socioeconomic vulnerabilities. An integrated and comprehensive strategy is required to reduce mortality in patients with MDR/RR-TB, particularly focusing on the early stages of treatment and target populations.

Factors affecting accuracy of clinical staging in resectable non-small cell lung cancer in a real-world study.

BACKGROUND: The clinical staging of non-small cell lung cancer (NSCLC) is well known to be related to their prognosis. However, there is usually a discrepancy between clinical staging and pathological staging. There are few analyses of clinical staging accuracy in patients with NSCLC. We compared the concordance rate between clinical and pathological staging of NSCLC and evaluated factors affecting the accuracy in real-world data. METHODS: Altogether, 811 patients with primary NSCLC who had undergone curative lung resection surgery in Severance Hospital from January 2019 to December 2020 were retrospectively reviewed. We used the eighth edition of the American Joint Committee on Cancer TNM staging. RESULTS: Among 811 patients, endobronchial ultrasound (EBUS) and positron emission tomography (PET-CT) were performed in 31.6% and 96.7%, respectively. The concordance rates between clinical and pathological TNM staging, T factor, and N factor, were 68.7%, 77.7%, and 85.8%, respectively. With multivariable logistic regression analysis, current smokers (OR 0.49; 95% CI: 0.32-0.76, p = 0.001) and a higher clinical stage (p < 0.001) contributed to the clinical staging inaccuracy. Additionally, the presence of a bronchoscopy specialist was significantly associated with clinical staging accuracy (OR 1.53; 95% CI: 1.10-2.13, p = 0.011). CONCLUSION: Clinical staging accuracy in NSCLC improved compared to before the widespread use of PET-CT and EBUS in clinical staging work-up. Smoking history and absence of expert bronchoscopy specialists showed a meaningful correlation with the inaccuracy of clinical staging. Thus, training more bronchoscopy experts would improve the staging accuracy of NSCLC, which could positively affect the prognosis of NSCLC.

A Quasi-experimental Study on the Effect of Pre-entry Tuberculosis Screening for Immigrants on Treatment Outcomes in South Korea: A Difference-in-Differences Analysis.

OBJECTIVE: This study ascertains the effects of the pre-entry tuberculosis (TB) screening policy, which was implemented as a strategy for managing TB among immigrants, on the treatment outcomes of immigrants in South Korea. METHODS: This study linked three different datasets from 2013 to 2018, namely (1) Korean National Tuberculosis Surveillance System; (2) National Health Information Database for patients diagnosed with TB with ICD code A15-A19, B90, or U84.3; and (3) Statistics Korea database related to cause of deaths. To identify the effect of the policy, cohorts comprising Korean and immigrant TB patients notified before (January 1, 2013-December 31, 2015) and after (September 1, 2016-December 31, 2018), the implementations of the policy were established. A difference-in-differences (DID) analysis of the treatment success and mortality rates was performed. RESULTS: Data from 100,262 TB patients were included in the analysis (before policy implementation: 1240 immigrants and 65,723 Koreans; after policy implementation: 256 immigrants and 33,043 Koreans). The propensity score matching-DID analysis results showed that the difference in the treatment success rate between immigrants and Koreans decreased significantly, from 16% before to 6% after the policy implementation. The difference in the mortality rate between the two groups decreased from - 3% before to - 1% after the policy implementation; however, this difference was insignificant. CONCLUSION: The treatment outcomes of immigrant TB patients in South Korea improved after the implementation of the pre-entry active TB screening policy. Future immigrant TB policies should consider establishing active patient support strategies and a healthcare collaboration system between countries.

Diagnosis of Primary Ciliary Dyskinesia via Whole Exome Sequencing and Histologic Findings.

PURPOSE: To assess the diagnostic potential of whole-exome sequencing (WES) and elucidate the clinical and genetic characteristics of primary ciliary dyskinesia (PCD) in the Korean population. MATERIALS AND METHODS: Forty-seven patients clinically suspected of having PCD were enrolled at a tertiary medical center. WES was performed in all patients, and seven patients received biopsy of cilia and transmission electron microscopy (TEM). RESULTS: Overall, PCD was diagnosed in 10 (21.3%) patients: eight by WES (8/47, 17%), four by TEM. Among patients diagnosed as PCD based on TEM results, two patients showed consistent results with WES and TEM of PCD (2/4, 50%). In addition, five patients, who were not included in the final PCD diagnosis group, had variants of unknown significance in PCD-related genes (5/47, 10.6%). The most frequent pathogenic (P)/likely pathogenic (LP) variants were detected in DNAH11 (n=4, 21.1%), DRC1 (n=4, 21.1%), and DNAH5 (n=4, 21.1%). Among the detected 17 P/LP variants in PCD-related genes in this study, 8 (47.1%) were identified as novel variants. Regarding the genotype-phenotype correlation in this study, the authors experienced severe PCD cases caused by the LP/P variants in MCIDAS, DRC1, and CCDC39. CONCLUSION: Through this study, we were able to confirm the value of WES as one of the diagnostic tools for PCD, which increases with TEM, rather than single gene tests. These results will prove useful to hospitals with limited access to PCD diagnostic testing but with relatively efficient in-house or outsourced access to genetic testing at a pre-symptomatic or early disease stage.

Disseminated Nontuberculous Mycobacterial Infection in a Tertiary Referral Hospital in South Korea: A Retrospective Observational Study.

PURPOSE: Disseminated nontuberculous mycobacterial (D-NTM) disease occurs primarily in immunocompromised hosts. However, these cases have rarely been reported in South Korea. This study aimed to describe the clinical manifestations, disease course, and underlying immune deficiencies of patients with D-NTM disease. MATERIALS AND METHODS: We retrospectively reviewed the cases of D-NTM disease from January 2005 to December 2019 at a tertiary referral hospital in South Korea. D-NTM disease was defined as a bloodstream infection or infection of two or more non-contiguous body organs with species identification. RESULTS: Of the 53342 mycobacterial samples from 23338 patients, extrapulmonary NTM was detected in 104 patients, and 3 (2.9%) were diagnosed with D-NTM disease. Mycobacterium avium was isolated from two patients, while M. abscessus subspecies abscessus was identified in one. The patients were aged between 18 and 25 years, and two patients were male. All patients were immunocompromised - one received lung transplantation, one was diagnosed with anhidrotic ectodermal dysplasia with T-cell immune deficiency, and one had monocytopenia and mycobacterial infection syndrome associated with GATA2 mutations. All patients underwent a standard macrolide-based regimen for >5 months, and their sputum tested negative. However, one patient died of bacterial sepsis, while the other two survived. CONCLUSION: D-NTM disease is rare in a tertiary referral center in South Korea. They occur primarily in immunocompromised patients at a relatively young age. Careful investigation of the underlying immune status is required when treating patients with D-NTM disease.

Cost-Effectiveness of Age-Expanding Strategy of Latent Tuberculosis Infection Treatment in Household Contacts in South Korea.

PURPOSE: The strategy of latent tuberculosis infection (LTBI) treatment in household tuberculosis (TB) contacts has been expanding in South Korea. However, there is little evidence of the cost-effectiveness of LTBI treatment in patients over 35 years of age. This study aimed to evaluate the cost-effectiveness of LTBI treatment among household TB contacts in different age groups in South Korea. MATERIALS AND METHODS: An age-structured model of TB was developed based on the reports from the Korea Disease Control and Prevention Agency and the National Health Insurance Service. Quality-adjusted life-years (QALY) and the averted number of TB-related deaths were estimated along with discounted costs for a measure of incremental cost-effectiveness ratios. RESULTS: The number of cumulative active TB cases would decrease by 1564 and 7450 under the scenario of LTBI treatment for those aged <35 years and <70 years, respectively, relative to the no-treatment scenario. The treatment strategies for patients aged 0 to <35 years, <55 years, <65 years, and <70 years would add 397, 1482, 3782, and 8491 QALYs at a cost of $660, $5930, $4560, and $2530, respectively, per QALY. For the averted TB-related deaths, LTBI treatment targeting those aged 0 to <35 years, <55 years, <65 years, and <70 years would avert 7, 89, 155, and 186 deaths at a cost of $35900, $99200, $111100, and $115700 per deaths, respectively, in 20 years. CONCLUSION: The age-specific expansion policy of LTBI treatment not only for those under 35 years of age but also for those under 65 years of age among household contacts was cost-effective in terms of QALYs and averted TB deaths.

Clinical features and molecular genetics associated with brain metastasis in suspected early-stage non-small cell lung cancer.

Introduction: Regarding whether brain magnetic resonance imaging (MRI) should be routine in patients with suspected early-stage lung cancer, guideline recommendations are inconsistent. Therefore, we performed this study to evaluate the incidence of and risk factors for brain metastasis (BM) in patients with suspected early-stage non-small-cell lung cancer (NSCLC). Methods: A review of the medical charts of consecutive NSCLC patients diagnosed between January 2006 and May 2020 was performed. We identified 1,382 NSCLC patients with clinical staging of T1/2aN0M0 (excluding BM), and investigated the incidence, clinical predictors, and prognosis of BM in the cohort. We also performed RNA-sequencing differential expression analysis using transcriptome of 8 patients, using DESeq2 package (version 1.32.0) with R (version 4.1.0). Results: Among 1,382 patients, nine hundred forty-nine patients (68.7%) underwent brain MRI during staging, and 34 patients (3.6%) were shown to have BM. Firth's bias-reduced logistic regression showed that tumor size (OR 1.056; 95% CI 1.009-1.106, p=0.018) was the only predictor of BM, and pathologic type was not a predictor of BM in our cohort (p>0.05). The median overall survival for patients with brain metastasis was 5.5 years, which is better than previously reported in the literature. RNA-sequencing differential expression analysis revealed the top 10 significantly upregulated genes and top 10 significantly downregulated genes. Among the genes involved in BM, Unc-79 homolog, non-selective sodium leak channel (NALCN) channel complex subunit (UNC79) was the most highly expressed gene in the lung adenocarcinoma tissues from the BM group, and an in vitro assay using A549 cells revealed that the NALCN inhibitor suppressed lung cancer cell proliferation and migration. Conclusions: Given the incidence and favorable outcome of BM in patients with suspected early-stage NSCLC, selective screening with brain MRI may be considered, especially in patients with high-risk features.

Healthcare use and medical cost before and after diagnosis of nontuberculous mycobacterial infection in Korea: the National Health Insurance Service-National Sample Cohort Study.

BACKGROUND AND OBJECTIVE: The global prevalence and incidence of nontuberculous mycobacterial (NTM) infections are increasing; however, population-level data on healthcare use and medical costs for people with NTM infections are limited. Thus, we investigated the rates of healthcare use and medical costs of people with NTM infections in South Korea using the National Health Insurance Service-National Sample Cohort from 2002 to 2015. METHODS: In this cohort study, people with and without NTM infection aged 20-89 years were matched 1 to 4 by sex, age, Charlson comorbidity index, and year of diagnosis. The overall and annual average healthcare use and medical costs were calculated. In addition, trends in healthcare use and medical costs for each of the 3 years before and after NTM diagnosis were investigated for people diagnosed with NTM infection. RESULTS: A total of 798 individuals (336 men and 462 women) diagnosed with NTM infection and 3192 controls were included in the study. NTM-infected patients had significantly higher rates of healthcare use and medical costs than those in the control group (p < 0.05). NTM-infected patients showed 1.5 times the medical cost and 4.5 times the respiratory disease cost of the control group. People diagnosed with NTM infection incurred the highest medical costs in the 6 months before diagnosis. CONCLUSION: NTM infection increases the economic burden on Korean adults. Appropriate diagnostic tests and treatment plans for NTM infections are needed to reduce the burden of the disease caused by such infection.

Gender differences in tuberculosis patients with comorbidity: A cross-sectional study using national surveillance data and national health insurance claims data in South Korea.

The coexistence of tuberculosis and other chronic diseases complicates disease management. Particularly, the lack of information on the difference in the prevalence of chronic diseases in tuberculosis based on age and gender can hinder the establishment of appropriate public health strategies. This study aimed to identify age- and gender-based differences in the prevalence of chronic diseases as comorbidities in patients with tuberculosis. An anonymized data source was established by linking the national health insurance claims data to the Korean national tuberculosis surveillance data from 2014 to 2018. The prevalence of chronic diseases was stratified by gender and age (age groups: ≤64, 65-74, and ≥75 years), and the differences in the prevalence of chronic diseases were analyzed by multinomial logistic regression and classified using the Charlson Comorbidity Index. A total of 148,055 patients with tuberculosis (61,199 women and 86,856 men) were included in this study. Among the patients aged ≥65 years, 48.2% were female and 38.1% were male. In this age group, the probability of chronic disease comorbidity was higher in female patients than in male patients. The prevalence of congestive heart failure and dementia as comorbidities in patients with tuberculosis increased more drastically with age in women than in men. Thus, the present study confirmed gender and age differences in the distribution of comorbidities among patients with tuberculosis. A more comprehensive gender-responsive approach for patients with tuberculosis and chronic diseases is required to alleviate the double burden of infectious diseases and non-communicable diseases in an aging society.

Clinical Outcomes and Prognosis of Patients With Interstitial Lung Disease Undergoing Lung Cancer Surgery: A Propensity Score Matching Study.

BACKGROUND: Patients with interstitial lung disease (ILD) may have a poor prognosis after lung cancer surgery because of respiratory complications and increased recurrence rates due to limited resection. Few studies have investigated prognosis after surgery by matching clinical variables between patients with and without ILD. PATIENTS AND METHODS: Medical records of patients who underwent lung cancer surgery between January 2010 and August 2020 at a referral hospital in South Korea were reviewed. Patients with ILD were identified based on preoperative computed tomography findings. Through propensity score matching, the clinical outcomes and prognoses of patients with (ILD group) and without ILD (control group) were compared. RESULTS: Of 1629 patients, 113 (6.9%) patients with ILD were identified, of whom 104 patients were matched. Before matching, patients with ILD had higher mean age, proportion of men, and rates of sublobar resection and squamous cell carcinoma than those without ILD. After matching, there was no significant difference in postoperative mortality rates between the control and ILD groups. The 5-year survival rate was significantly lower in the ILD group (66%) than in the control group (78.8%; P= .007). The 5-year survival rate of the ILD-GAP (Gender, Age, Physiology) stage III group (12.6%) was significantly lower than that of the ILD-GAP stage I (73.5%) and II groups (72.6%; P< .0001). Multivariable Cox analysis demonstrated that idiopathic pulmonary fibrosis, higher clinical stage, and recurrence were independent prognostic factors for mortality. CONCLUSION: Concomitant ILD negatively affects long-term prognosis after lung cancer surgery, and ILD subtype and physiological severity assessment help predict prognosis after surgery.

Protective effect of methotrexate on lung function and mortality in rheumatoid arthritis-related interstitial lung disease: a retrospective cohort study.

BACKGROUND: Studies on the risk and protective factors for lung function decline and mortality in rheumatoid arthritis-related interstitial lung disease (RA-ILD) are limited. OBJECTIVES: We aimed to investigate clinical factors and medication uses associated with lung function decline and mortality in RA-ILD. METHODS: This retrospective cohort study examined the medical records of patients with RA-ILD who visited Severance Hospital between January 2006 and December 2019. We selected 170 patients with RA-ILD who had undergone at least one spirometry test and chest computed tomography scan. An absolute decline of ⩾10% in the functional vital capacity (FVC) was defined as significant decline in pulmonary function. Data for analysis were retrieved from electronic medical records. RESULTS: Ninety patients (52.9%) were female; the mean age was 64.0 ± 10.2 years. Multivariate logistic regression showed that a high erythrocyte sediment rate level at baseline [odds ratio (OR) = 3.056; 95% confidence interval (CI) = 1.183-7.890] and methotrexate (MTX) use (OR = 0.269; 95% CI = 0.094-0.769) were risk and protective factors for lung function decline, respectively. Multivariate Cox regression analysis indicated that age ⩾65 years (OR = 2.723; 95% CI = 1.142-6.491), radiologic pattern of usual interstitial pneumonia (UIP) or probable UIP (OR = 3.948; 95% CI = 1.522-10.242), baseline functional vital capacity (FVC) % predicted (OR = 0.971; 95% CI = 0.948-0.994), and MTX use (OR = 0.284; 95% CI = 0.091-0.880) were predictive of mortality. CONCLUSION: We identified risk and protective factors for lung function decline and mortality in patients with RA-ILD. MTX use was associated with favorable outcome in terms of both lung function and mortality in our cohort.

Comorbidities of nontuberculous mycobacteria infection in Korean adults: results from the National Health Insurance Service-National Sample Cohort (NHIS-NSC) database.

BACKGROUND: The global prevalence and incidence of nontuberculous mycobacteria (NTM) infection are increasing. However, the prevalence of NTM infection-associated comorbidities remains understudied. Thus, we investigated the comorbidities associated with NTM infection using the National Health Insurance Service-National Sample Cohort (NHIS-NSC) 2.0 database of the National Health Insurance Service (NHIS). METHODS: In this case-control study, patients with NTM infection and controls aged 20-89 years of age were matched 1:4 by sex, age, region, and income. A total of 26 comorbidities were selected based on previous reports and claims data analysis. The distribution of comorbidities was compared between patients with NTM infection and controls by sex and age using logistic regression analysis. RESULTS: In total, 893 patients (379 men and 514 women) with NTM infection (mean age, 56.1 years) and 3,572 controls (mean age, 55.6 years) were included. The odds ratio for prevalence of respiratory diseases, metabolic diseases, musculoskeletal disorders, gastrointestinal diseases, skin diseases, mental diseases, and neoplasms was significantly higher in patients with NTM infection than in the control group. Among comorbid diseases, the odds ratios (ORs) for the prevalence of the respiratory diseases such as bronchiectasis (OR [95% confidence interval (CI)]: 26.79 [19.69-36.45]) and interstitial pneumonitis (OR [95% CI]: 15.10 [7.15-31.89]) were the highest. No significant differences were observed in NTM infection-related comorbidities between men and women. In the younger age group (20-39 years old), the prevalence of respiratory and systemic diseases such as hypertension and diabetes was higher in the patient group than in the control group. CONCLUSIONS: NTM infection is associated with several respiratory and systemic diseases that should be considered when providing medical care to patients with NTM infection.

Long-term clinical course and progression of lymphangioleiomyomatosis in a single lung transplant referral centre in Korea.

We aimed to describe the clinical features of lymphangioleiomyomatosis (LAM) in Korean patients and identify factors associated with progressive disease (PD). Clinical features of 54 patients with definite or probable LAM from 2005 to 2018 were retrospectively analysed. Common features were pneumothorax (66.7%) and abdominal lymphadenopathy (50.0%). Twenty-three (42.6%) patients were initially treated with mechanistic target of rapamycin (mTOR) inhibitors. Lung transplantation (LT) was performed in 13 (24.1%) patients. Grouped based on the annual decline in forced expiratory volume in 1 s (FEV1) from baseline and LT, 36 (66.7%) patients exhibited stable disease (SD). All six deaths (11.1%) occurred in PD. Proportion of SD was higher in those treated initially with mTOR inhibitors than in those under observation (p = 0.043). Univariate analysis revealed sirolimus use, and baseline forced vital capacity, FEV1, and diffusing capacity of the lungs for carbon monoxide are associated with PD. Multivariate analysis showed that only sirolimus use (odds ratio 0.141, 95% confidence interval 0.021-0.949, p = 0.044) reduced PD. Kaplan-Meier analysis estimates overall survival of 92.0% and 74.7% at 5 and 10 years, respectively. A considerable proportion of LAM patients remain clinically stable without treatment. LT is an increasingly viable option for patients with severe lung function decline.

Identification of MicroRNAs as Potential Blood-Based Biomarkers for Diagnosis and Therapeutic Monitoring of Active Tuberculosis.

Early diagnosis increases the treatment success rate for active tuberculosis (ATB) and decreases mortality. MicroRNAs (miRNAs) have been studied as blood-based markers of several infectious diseases. We performed miRNA profiling to identify differentially expressed (DE) miRNAs using whole blood samples from 10 healthy controls (HCs), 15 subjects with latent tuberculosis infection (LTBI), and 12 patients with ATB, and investigated the expression of the top six miRNAs at diagnosis and over the treatment period in addition to performing miRNA-target gene network and gene ontology analyses. miRNA profiling identified 84 DE miRNAs in patients with ATB, including 80 upregulated and four downregulated miRNAs. Receiver operating characteristic curves of the top six miRNAs exhibited excellent distinguishing efficiency with an area under curve (AUC) value > 0.85. Among them, miR-199a-3p and miR-6886-3p can differentiate between ATB and LTBI. Anti-TB treatment restored the levels of miR-199b-3p, miR-199a-3p, miR-16-5p, and miR-374c-5p to HC levels. Furthermore, 108 predicted target genes were related to the regulation of cellular amide metabolism, intrinsic apoptotic signaling, translation, transforming growth factor beta receptor signaling, and cysteine-type endopeptidase activity. The DE miRNAs identified herein are potential biomarkers for diagnosis and therapeutic monitoring in ATB.

Reference values of skeletal muscle area for diagnosis of sarcopenia using chest computed tomography in Asian general population.

BACKGROUND: Diagnostic cutoff points for sarcopenia in chest computed tomography (CT) have not been established although CT is widely used for investigating skeletal muscles. This study aimed to determine reference values for sarcopenia of thoracic skeletal muscles acquired from chest CT scans and to analyse variables related to sarcopenia using the cutoff values determined in a general Asian population. METHODS: We retrospectively reviewed chest CT scans of 4470 participants (mean age 54.8 ± 9.9 years, 65.8% male) performed at a check-up centre in South Korea (January 2016-August 2017). To determine cutoffs, 335 participants aged 19-39 years (mean age 35.2 ± 3.6 years, 75.2% male) were selected as the healthy and younger reference group, and 4135 participants aged ≥40 years (mean age 56.4 ± 8.4 years, 65.1% male) were selected as the study group. We measured the following: cross-sectional area (CSA) of the pectoralis, intercostalis, paraspinal, serratus, and latissimus muscles at the 4th vertebral region (T4CSA ); T4CSA divided by height2 (T4MI); pectoralis muscle area (PMCSA ); and PMCSA divided by height2 (PMI) at the 4th vertebral region. Sarcopenia cutoff was defined as sex-specific values of less than -2 SD below the mean from the reference group. RESULTS: In the reference group, T4CSA , T4MI, PMCSA , and PMI cutoffs for sarcopenia were 100.06cm2 , 33.69cm2 /m2 , 29.00cm2 , and 10.17cm2 /m2 in male, and 66.93cm2 , 26.01cm2 /m2 , 18.29cm2 , and 7.31cm2 /m2 in female, respectively. The prevalence of sarcopenia in the study group measured with T4CSA , T4MI, PMCSA and PMI cutoffs were 11.4%, 8.7%, 8.5%, and 10.1%, respectively. Correlations were observed between appendicular skeletal mass divided by height2 measured by bioelectrical impedance analysis (BIA) and T4CSA (r = 0.82; P < 0.001)/T4MI (r = 0.68; P < 0.001), and ASM/height2 measured by BIA and PMCSA (r = 0.72; P < 0.001)/PMI (r = 0.63; P < 0.001). In the multivariate logistic regression models, sarcopenia defined by T4CSA /T4MI were related to age [odds ratio (95% confidence interval), P-values: 1.09 (1.07-1.11), <0.001/1.05 (1.04-1.07), <0.001] and diabetes [1.60 (1.14-2.25), 0.007/1.47 (1.01-2.14), 0.043]. Sarcopenia defined by PMCSA /PMI were related to age [1.09 (1.08-1.10), <0.001/1.05 (1.03-1.06), <0.001], male sex [0.23 (0.18-0.30), <0.001/0.47 (0.32-0.71), <0.001], diabetes [2.30 (1.73-3.05), <0.001/1.63 (1.15-2.32), 0.007], history of cancer [2.51 (1.78-3.55), <0.001/1.61 (1.04-2.48), 0.033], and sufficient physical activity [0.67 (0.50-0.89), 0.007/0.74 (0.56-0.99), 0.042]. CONCLUSIONS: The reference cutoff values of a general population reported here will enable sex-specific standardization of thoracic muscle mass quantification and sarcopenia assessment.

Nontuberculous mycobacterial infection after lung transplantation: A single-center experience in South Korea.

PURPOSE: Nontuberculous mycobacteria (NTM) infection is an important issue after lung transplantation. However, a large-scale epidemiological study on this issue in Korea is lacking. We aimed to evaluate the epidemiology of NTM infection after lung transplant surgery in Korea. METHODS: Between October 2012 and December 2018, we retrospectively evaluated lung transplant recipients in a referral hospital in South Korea. A total of 215 recipients were enrolled. The median age at transplantation was 56 years (range, 17-75), and 62% were men. Bronchoscopy was performed according to the surveillance protocol and clinical indications. A diagnosis of NTM infection was defined as a positive NTM culture from a bronchial washing, bronchoalveolar lavage sample, or two separate sputum samples. We determined NTM pulmonary disease (NTM-PD) according to the American Thoracic Society/Infectious Disease Society of America 2007 guidelines. The Kaplan-Meier method and log-rank test were used for conditional survival analysis in patients with follow-up of ≥12 months. RESULTS: Fourteen patients (6.5%) were diagnosed with NTM infection at a median of 11.8 months (range, 0.3-51.4) after transplantation. Nine patients (4.2%) were diagnosed with NTM-PD, and the incidence rate was 1980/100,000 person-years. Mycobacterium abscessus was the most common species causing NTM-PD (66%), followed by M. avium complex (33%). The presence of NTM infection did not influence all-cause mortality among those who underwent follow-up for ≥12 months (N = 133, log-rank P = 0.816). CONCLUSION: The incidence of NTM-PD was considerably high among lung-transplant recipients. M. abscessus was the most common causative species of NTM-PD after lung transplantation.

Association between Dietary Patterns and Chronic Obstructive Pulmonary Disease in Korean Adults: The Korean Genome and Epidemiology Study.

In addition to smoking, dietary habits may contribute to the development of chronic obstructive pulmonary disease (COPD). This study aimed to examine the association between dietary patterns and lung function in a Korean community cohort. A total of 5436 participants were included from the Ansan-Ansung cohort study. To identify the dietary patterns, we performed principal component factor analysis using the results of a semi-quantitative food frequency questionnaire. The forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio were measured by spirometry. Multiple logistic regression models were used to evaluate the association between dietary patterns and lung function after adjusting for confounders. We identified four major dietary patterns; 'prudent', 'coffee, fat, and sweet', 'westernized', and 'white rice'. After adjusting for potential confounders, the 'coffee, fat, and sweet' dietary pattern was negatively associated with lung function, particularly the FEV1/FVC ratio. Participants with high scores for the 'coffee, fat and sweet' pattern had a higher risk of COPD among men but not women. Therefore, these results indicate that the 'coffee, fat and sweet' dietary pattern is inversely related to lung function in Korean adults. Our results indicate that dietary habits may be modifiable risk factors for COPD.

Relationship of the lung microbiome with PD-L1 expression and immunotherapy response in lung cancer.

BACKGROUND: Lung cancer is the primary cause of cancer-related deaths worldwide. The human lung serves as a niche to a unique and dynamic bacterial community that is related to the development of multiple diseases. Here, we investigated the differences in the lung microbiomes of patients with lung cancer. METHODS: 16S rRNA sequencing was performed to evaluate the respiratory tract microbiome present in the bronchoalveolar lavage fluid. Patients were stratified based on programmed death-ligand 1 (PD-L1) expression levels and immunotherapy responses. RESULTS: In total, 84 patients were prospectively analyzed, of which 59 showed low (< 10%), and 25 showed high (≥ 10%) PD-L1 expression levels. The alpha and beta diversities did not significantly differ between the two groups. Veillonella dispar was dominant in the high-PD-L1 group; the population of Neisseria was significantly higher in the low-PD-L1 group than in the high-PD-L1 group. In the immunotherapy responder group, V. dispar was dominant, while Haemophilus influenzae and Neisseria perflava were dominant in the non-responder group. CONCLUSION: The abundances of Neisseria and V. dispar differed significantly in relation to PD-L1 expression levels and immunotherapy responses.

Association of protein consumption and energy intake on sarcopenia in tuberculosis survivors.

BACKGROUND: Tuberculosis (TB) causes undernutrition, and it has a long recovery time after treatment. It is accompanied by adverse health outcomes, such as sarcopenia. OBJECTIVE: We aimed to evaluate the prevalence of sarcopenia and its association with protein and total energy intakes among Korean TB survivors. METHODS: Data of the population-based Korea National Health and Nutrition Examination Survey (2008-2011) were analyzed, including 9,203 participants aged ⩾ 40 years. We used three definitions for sarcopenia-appendicular skeletal muscle mass (ASM, kg) divided by body mass index (BMI, kg/m2), weight (kg), or height squared (m2). Daily protein and total energy intakes were estimated with a 24-h recall method. Multiple logistic regression was used to evaluate the association between dietary protein/total energy intake and sarcopenia among TB survivors. RESULTS: The prevalence of sarcopenia was 11.2%, 10.7%, and 24.3% among TB survivors with sarcopenia defined by ASM divided by BMI, weight, and height squared, respectively. The prevalence of sarcopenia among TB survivors was higher than among those without TB. After adjusting for age, weight, sex, education level, employment status, smoking status, and drinking status, sufficient protein and total energy intakes were associated with a lower risk of sarcopenia in TB survivors. CONCLUSION: The prevalence of sarcopenia was higher in TB survivors than in those without TB. We suggest consuming sufficient protein intake along with increasing total energy intake in TB survivors.

Impact of non-cystic fibrosis bronchiectasis on critically ill patients in Korea: a retrospective observational study.

This study investigated the impact of bronchiectasis on patients admitted to the intensive care unit (ICU) at a hospital in Korea. Patients with bronchiectasis were diagnosed using results of chest computed tomography performed before ICU admission. The severity of bronchiectasis was based on the number of affected lobes, and patients with ≥ 3 bronchiectatic lobes were classified into the severe bronchiectasis group. Overall, 823 patients were enrolled. The mean age was 66.0 ± 13.9 years, and 63.4% were men. Bronchiectasis and severe bronchiectasis were present in 148 (18.0%) and 108 (13.1%) patients, respectively. The increase in the number of bronchiectatic lobes was related to the rise in ICU mortality (P for trend = 0.012) and in-hospital mortality (P for trend = 0.004). Patients with severe bronchiectasis had higher odds for 28-day mortality [odds ratio (OR) 1.122, 95% confidence interval (CI) 1.024-1.230], ICU mortality (OR 1.119, 95% CI 1.023-1.223), and in-hospital mortality (OR 1.208, 95% CI 1.092-1.337). The severe bronchiectasis group showed lower overall survival (log-rank P < 0.001), and the adjusted hazard ratio was 1.535 (95% CI 1.178-2.001). Severe bronchiectasis had a negative impact on all-cause mortality during ICU and hospital stays, resulting in a lower survival rate.