BACKGROUND:Tuberculosis (TB) remains a public health concern in South Korea despite declining national notifications. We evaluated temporal changes in clinical characteristics, diagnostic patterns, and treatment outcomes in the Korean Tuberculosis Cohort (KTBC) from 2019 to 2024. METHODS:We retrospectively analyzed prospectively collected data from the multicenter KTBC registry from January 2019 to December 2024. Overall analyses used the full cohort including extrapulmonary TB; radiographic, microbiologic, bronchoscopy, and drug-susceptibility analyses were restricted to patients with pulmonary involvement. Calendar year was treated as an ordinal variable, with trends tested by linear regression or the Cochran-Armitage test (P for trend). RESULTS:Among 33,826 patients, the proportion aged ≥65 years increased from 46.9% in 2019 to 54.8% in 2024 and any comorbidity from 59.6% to 71.5%. Among 26,271 patients with pulmonary involvement, chest radiography (CXR) findings suspicious for TB decreased from 71.2% to 42.3% and CXR cavitation from 18.0% to 9.0%, whereas computed tomography-detected cavitation decreased only modestly (20.4% to 17.7%). Xpert MTB/RIF testing increased from 41.5% to 77.0%, bronchoscopic yield from 71.2% to 81.8%, and treatment success from 59.7% to 70.0%, whereas mortality decreased from 10.0% to 7.3% and isoniazid resistance from 9.1% to 6.5% (all P for trend ≤0.011). CONCLUSION:TB care in South Korea increasingly involves older and medically complex patients. Pulmonary TB became less recognizable on initial chest radiography, whereas molecular testing, bronchoscopic confirmation, and treatment outcomes improved. These findings support public-private mix-based quality monitoring, integrated care for vulnerable patients, and diagnostic pathways adapted to less typical radiographic presentations.
BACKGROUND:Particulate matter with an aerodynamic diameter ≤10 μm (PM10) is a major environmental pollutant implicated in chronic airway injury and remodeling. This study investigated the effects of chronic PM10 exposure on epithelial barrier integrity, cellular differentiation, surfactant expression, and inflammatory signaling in a human small airway epithelial air-liquid interface (ALI) model. METHODS:Differentiated ALI cultures were exposed to PM10 for 7, 14, and 21 days. Transepithelial electrical resistance (TEER), epithelial lineage markers, surfactant proteins, inflammatory cytokines, and signaling pathways were analyzed using RT-PCR, ELISA, and western blotting. RESULTS:PM10 exposure significantly reduced TEER over time indicating progressive epithelial barrier dysfunction. Club cell and ciliated cell markers decreased, whereas basal cell markers remained relatively preserved, suggesting impaired epithelial differentiation. Surfactant mRNA levels, particularly SP-A and SP-B, were reduced, while secreted SP-A paradoxically increased and SP-B secretion decreased. Pro-inflammatory cytokines, including IL-1β, IL-6, IL-8, and TNF-α, were significantly elevated. In addition, cleaved Notch1, Notch3, phosphorylated NF-κB and IκBα, and the downstream Notch targets HES1 and HEY1 were increased in PM10 -exposed cells. CONCLUSION:Chronic PM10 exposure disrupts airway epithelial barrier integrity and impairs epithelial differentiation and function, accompanied by inflammatory activation through the Notch and NF-κB signaling pathways. These findings suggest a biologically plausible mechanistic link between environmental PM10 exposure and chronic airway epithelial dysfunction.
BACKGROUND:Reliable assessment of adherence to inhaled maintenance therapy is important in COPD management, yet no validated Vietnamese instruments have been available. This study translated and validated the Vietnamese versions of the Test of Adherence to Inhalers (TAI) and the Inhaler Medication Adherence Scale (IMAS). METHODS:A mixed-methods design was used. Phase 1 included forward-back translation, expert review, and cognitive testing to ensure semantic and cultural equivalence. Phase 2 was a cross-sectional survey of 210 clinically stable COPD patients at a tertiary outpatient clinic. Content validity, exploratory factor analysis (EFA), internal consistency, and four-week test-retest reliability were assessed. Content validity indexes were calculated from independent expert ratings using a four-point relevance scale. Associations with clinical indicators were examined using Spearman correlation. RESULTS:Content validity was high for both instruments (TAI S-CVI/Ave = 1.00; IMAS S-CVI/Ave = 0.96), and patient comprehension was excellent. EFA identified two components for the TAI, explaining 65.25% of variance, and four components for the IMAS, accounting for 74.27% of variance. Internal consistency was strong (TAI alpha = 0.87; IMAS alpha = 0.91), and reliability across age and symptom subgroups remained robust. Test-retest stability was high (ICC: TAI = 0.88; IMAS = 0.89). A moderate correlation between TAI and IMAS (rho = 0.43, p < 0.001) indicated that the two scales capture related but distinct behavioral and psychological aspects of adherence. CONCLUSION:The Vietnamese TAI and IMAS demonstrate good reliability, validity, and cultural suitability for assessing inhaler adherence in COPD. Their combined use may support routine evaluation, patient counseling, and adherence-focused research in Vietnam.
BACKGROUND:The COVID-19 pandemic disrupted global tuberculosis (TB) control, raising concerns about its impact on diagnosis, treatment outcomes, and latent infection management. Korea's Public-Private Mix (PPM) TB control project integrates private providers into national TB services. This study evaluated early pandemic trends in TB care and prevention within the PPM project. METHODS:Nationwide PPM cohort data from July 2019 to December 2021 were analyzed across five semi-annual periods. Monitoring indicators included diagnostic coverage, treatment success and completion, all-cause death, contact investigation, and initiation of TB preventive treatment (TPT). Trends were assessed using chi-square tests for trend. RESULTS:Diagnostic coverage increased significantly across most modalities (P < 0.001), except phenotypic drug susceptibility testing. Twelve-month treatment completion rate improved overall (P = 0.005), particularly among people < 65 years (P < 0.001) and new cases (P = 0.039). Treatment success rate remained stable (P = 0.123) but declined in those > 65 years (P = 0.030). All-cause death rate increased from 12.2% to 14.9% (P < 0.001), largely due to non-TB-related deaths. Contact investigation coverage peaked in early 2020 and subsequently declined, whereas TPT coverage rose steadily throughout the study period (P < 0.001). CONCLUSION:Despite global disruptions, Korea's PPM project maintained essential TB services during the early pandemic, with improvements in diagnostic testing and TPT uptake. However, increased death rates and declining treatment success among older adults warrant careful interpretation and suggest the need for continued monitoring and tailored support. Ongoing monitoring of TB indicators will be important to understand the longer-term impact of the pandemic on TB care and prevention.
BACKGROUND:The epidemiology of pneumococcal pneumonia can be influenced by vaccine implementation, serotype replacement, and viral circulation. We aimed to investigate 15-year trends in the epidemiological and clinical characteristics of severe pneumococcal pneumonia patients requiring intensive care unit (ICU) admission. METHODS:We analyzed data from a prospective cohort of adult patients with severe pneumonia admitted to the 28-bed medical ICU of a 2,700-bed tertiary hospital in South Korea between 2010 and 2024. Temporal changes in incidence, resistance to antimicrobial agents, frequency of co-infections, and mortality were evaluated across three 5-year periods. RESULTS:Among 2,511 ICU patients with severe pneumonia, 140 (5.6%) had pneumococcal infections. The proportion of pneumococcal cases decreased from 9.9% in 2010-2014 to 4.2% in 2015-2019, and further to 2.2% in 2020-2024 (p<0.001 for trend). Conversely, ceftriaxone non-susceptibility rates rose sharply from 4.8% to 16.7% and 45.5% across the same periods (p<0.001). Co-infections were frequent and increased significantly, largely due to respiratory viruses, with rates of 48.9%, 61.8%, and 77.8%, respectively (p=0.02). Influenza was the predominant co-pathogen during 2015-2019, whereas SARS-CoV-2 was most frequent in 2020-2024. The 90-day mortality rates remained stable over time (29.5%, 38.2%, and 27.8%, p=0.64). CONCLUSIONS:In this single-center ICU cohort, the proportion of severe pneumococcal pneumonia cases decreased over the 15-year period, whereas ceftriaxone non-susceptibility and viral co-infections became more frequent. These trends should be interpreted cautiously given the lack of serotype and individual vaccination data and incomplete susceptibility results. Continued surveillance of pneumococcal disease, antimicrobial resistance, and respiratory co-infections is warranted.
BACKGROUND:Chronic obstructive pulmonary disease (COPD) is a condition with high prevalence and mortality, causing a substantial disease burden. Airway mucus hypersecretion (AMH) is clinically associated with impaired pulmonary function, diminished quality of life, and increased mortality in COPD patients. The purpose of this bibliometric research was to identify research developments and emerging hotspots within the field of AMH and COPD by providing a comprehensive overview of the current research landscape. METHODS:The Web of Science core (WOSCC) database was searched for publications addressing COPD and AMH from January 1, 1994, to December 31, 2024. A total of 1,405 publications were retrieved and subjected to bibliometric and visual analyses using CiteSpace, VOSviewer, and R software. RESULTS:From 1994 to 2024, both publication output and citation frequency in this field demonstrated a sustained upward trajectory. The United States of America (USA) occupies a prominent position in this domain, characterized by substantial collaborative networks and research productivity. While extensive inter-country and inter-institutional collaborations were evident, researcher-level collaborations remained relatively fragmented. Notably, Boucher, Richard C. received substantial recognition owing to his exceptional research productivity and citation impact. Keywords including exacerbations, autophagy, and mucus plugs exhibited the strongest citation bursts during 2023--2024. Conclusions:This research illustrates the present landscape, focal points, and future directions in the fields of COPD and AMH. Researchers may benefit from obtaining a rapid synopsis, along with citations and innovative concepts, to facilitate and inform subsequent investigations.
BACKGROUND:Exercise-induced desaturation (EID) during the 6-minute walk test (6MWT) is an established marker of adverse outcomes in patients with chronic obstructive pulmonary disease (COPD). We therefore sought to develop a screening-oriented machine learning approach to identify patients at increased risk of EID. METHODS:We analyzed data from the nationwide, multicenter Korea COPD Subgroup Study (KOCOSS). EID was defined as peripheral oxygen saturation (SpO2) < 90% with a decrease of ≥ 4%p. The cohort was stratified into training (80%) and test (20%) sets. Candidate predictors were selected using the Boruta algorithm, and models were developed using multivariable logistic regression (MLR), extreme gradient boosting (XGB), random forest (RF), and support vector classification (SVC), with a screening-oriented threshold strategy prioritizing sensitivity. RESULTS:Among 1,788 patients with COPD, 185 (10.3%) exhibited EID. All models showed high area under the precision-recall curve (PR-AUC) during internal validation. Predictors selected by the Boruta algorithm included body mass index, COPD Assessment Test, St. George's Respiratory Questionnaire-C, mental health indicators, pulmonary function parameters, X-ray-identified bronchiectasis, and hemoglobin level. In the independent test set, PR-AUC declined across models while calibration metrics showed modest differences between datasets. The XGB model achieved the highest sensitivity in internal validation and its sensitivity and specificity remained relatively stable in the test set. Baseline SpO2 and diffusion capacity of the lung for carbon monoxide were the most influential predictors. CONCLUSION:A screening-oriented machine learning approach using routinely available variables may facilitate targeted referral for the 6MWT in COPD.
BACKGROUND:Peripheral blood eosinophil count has been associated with bronchiectasis outcomes, but findings are inconsistent. Its role in acute exacerbations among Korean patients remain unclear. METHODS:This study retrospectively evaluated 492 patients with bronchiectasis at a tertiary hospital in Korea between 2014 and 2021. Using a negative binomial regression model adjusted for follow-up duration, we evaluated the association between peripheral eosinophil counts and acute exacerbations in Korean patients with bronchiectasis. RESULTS:Among the 492 patients, 190 (38.6%) were categorized into the lower eosinophilic group, 221 (44.9%) into the normal eosinophilic group, and 80 (16.2%) into the higher eosinophilic group. No significant differences were observed across eosinophilic groups in terms of hospitalization within one year, BSI scores, or FACED scores (all p > 0.05). In the parsimonious negative binomial regression analysis with false discovery rate (FDR) correction, oral corticosteroid use (IRR = 2.26; 95% CI: 1.46-3.52; FDR p = 0.001), older age (IRR = 1.03; 95% CI: 1.01-1.04; FDR p = 0.002), and lower FEV1 % predicted (IRR = 0.98; 95% CI: 0.97-0.99; FDR p < 0.001) were identified as independent risk factors for acute exacerbations. Conclusions:There was no significant association between peripheral blood eosinophil counts and either acute exacerbations or disease severity in Korean patients with bronchiectasis. In contrast, older age, lower lung function (FEV1 % predicted), and the use of oral corticosteroids were identified as independent risk factors for acute exacerbations. These findings underscore the importance of considering region-specific clinical and epidemiological factors in the management of bronchiectasis.
BACKGROUND:Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic lung disease with high mortality. Population-based data on long-term epidemiological trends and real-world treatment outcomes in Asia remain limited. This study described national trends in IPF prevalence and incidence in South Korea and evaluated pirfenidone use and associated mortality. METHODS:Using the Korean National Health Insurance Service customized research database, we identified prevalent IPF cases from 2010 to 2023 and incident cases from 2011 to 2023. IPF was defined using the International Classification of Diseases, 10th Revision, and rare incurable disease codes, based on a predefined operational definition. Among incident cases, the association between pirfenidone use and all-cause mortality was assessed using multivariable-adjusted Cox proportional hazards models. RESULTS:A total of 91,638 prevalent and 28,683 incident IPF cases were identified during the study period. The crude prevalence increased from 8.91 per 100,000 persons ≥50 years in 2010 to 63.78 per 100,000 in 2023. The crude incidence increased from 6.07 per 100,000 in 2011 to 16.86 per 100,000 in 2023. Similar increasing patterns were observed for age- and sex-standardized rates. IPF was more common in men, and demonstrated a pronounced age gradient. Following reimbursement approval, pirfenidone use increased substantially. Pirfenidone use was associated with a reduced risk of all-cause mortality (adjusted hazard ratio, 0.627; 95% confidence interval, 0.600-0.665), with progressively stronger associations observed with longer treatment duration. CONCLUSION:The burden of IPF in South Korea has increased over the past decade, during which expanded real-world pirfenidone use was associated with improved survival.
BACKGROUND:Rare interstitial lung diseases (ILDs) are a heterogeneous group of diffuse parenchymal lung disorders with low prevalence and diverse etiologies that pose diagnostic and therapeutic challenges. We aimed to establish a nationwide, multicenter registry of rare ILDs in South Korea to characterize their clinical features and outcomes. METHODS:We conducted a multicenter, observational cohort study involving 304 patients with rare ILDs including Birt-Hogg-Dubé syndrome (BHD), lymphangioleiomyomatosis (LAM), pulmonary alveolar proteinosis (PAP), pulmonary Langerhans cell histiocytosis (PLCH), pleuroparenchymal fibroelastosis (PPFE), and hypersensitivity pneumonitis (HP) enrolled across 20 centers in Korea between September 2023 and December 2024. Data on clinical characteristics, outcomes, and treatment were collected. RESULTS:LAM (28.3%) and PAP (26.6%) were the most prevalent, followed by BHD (18.1%), PLCH (13.2%), HP (7.6%), and PPFE (6.3%). Dyspnea was common in HP and PPFE, whereas BHD and LAM were often asymptomatic. Pneumothorax was frequent in BHD (44.6%) and LAM (11.6%) at diagnosis. PPFE showed the most impaired lung function and the highest mortality (26.3%), during a median follow-up of 69.5 months, followed by PAP (6.2%) and BHD (1.8%). During follow-up, cancer was reported in 25.0% of patients with BHD. Treatment strategies varied by disease: corticosteroids were commonly used in HP (86.9%), PPFE (42.1%), and PLCH (32.5%); sirolimus in LAM (53.5%); pirfenidone in PPFE (42.1%); and whole-lung lavage in PAP (23.5%). CONCLUSION:This is the first nationwide rare ILD registry in Korea, demonstrating heterogeneity in clinical features and outcomes and emphasizing the need for disease-specific diagnostic and therapeutic strategies.
BACKGROUND:Pulmonary hypertension (PH) is a heterogeneous disorder with substantial morbidity and mortality. Thrombotic remodeling of pulmonary vasculature is a recognized contributor to disease progression, particularly in pulmonary arterial hypertension (PAH), prompting interest in anticoagulation as a potential adjunctive therapy. Despite the frequent use, anticoagulants continue to remain a controversial therapy across various subtypes of PH. METHODS:This review structurally evaluated published studies and evidence around the risks and benefits of anticoagulation across all five PH groups. Relevant peer-reviewed clinical trials, observational studies, and meta-analyses were identified through searches of PubMed, the Cochrane Library, and Google Scholar and were reviewed for survival outcomes, thromboembolic events, hemodynamics, and bleeding complications associated with anticoagulant use in PH. RESULTS:Evidence suggests that anticoagulation may provide a survival benefit in idiopathic PAH, while outcomes in connective tissue disease-associated PAH appear neutral or unfavorable due to increased bleeding risk. In other PH groups, anticoagulation has not demonstrated clear benefit and is generally reserved for standard indications such as atrial fibrillation or venous thromboembolism, except in chronic thromboembolic pulmonary hypertension, where it remains a cornerstone of therapy. Conclusion:There is currently no clear consensus on anticoagulation strategies across most pulmonary hypertension subtypes (except group 4). Given the heterogeneity of pulmonary hypertension, further well-designed prospective trials and PH-specific risk stratification tools are needed to clarify the role of anticoagulation and advance precision-based care in pulmonary hypertension.
BACKGROUND:Fluticasone furoate/umeclidinium/vilanterol (FF/UMEC/VI) is a single-inhaler triple therapy administered via the ELLIPTA inhaler. FF/UMEC/VI 100/62.5/25µg was approved in Korea to treat COPD in 2018 and asthma in 2022 (100/62.5/25µg and 200/62.5/25µg). Safety and efficacy of FF/UMEC/VI are well established in global clinical trials, though Korean real-world evidence remains limited. METHODS:This Korean multicentre post-marketing surveillance assessed safety and clinical outcomes of FF/UMEC/VI 100/62.5/25µg in COPD (May 2018-May 2024) and safety of FF/UMEC/VI in asthma (100/62.5/25µg: August 2022-May 2024; 200/62.5/25µg: September 2022-May 2024). Safety was assessed by total, serious and unexpected adverse event (AE) and adverse drug reaction (ADR) incidence. For COPD, physicians assessed within-patient improvement in clinical outcomes (lung function [FEV1, FVC], exacerbations and symptoms [mMRC dyspnoea, CAT]). RESULTS:Overall, 606 patients with COPD and 132 patients with asthma were evaluated. Mean (SD) administration for FF/UMEC/VI 100/62.5/25µg was 254.11(119.97) days overall; 271.83(104.99) for COPD; 20.74(10.87) for integrated asthma; 34.17(13.06) days for asthma with FF/UMEC/VI 200/62.5/25µg. ADRs occurred in 2.64% (16/606) of patients with COPD and 3.79% (5/132) with asthma. Most ADRs were mild; all serious/unexpected ADRs resolved. Of 33 patients with COPD who reported pneumonia, all events were considered unlikely to be treatment-related. Physicians determined improvement in 74.87% (283/378) of patients with COPD post- versus pre-FF/UMEC/VI administration. Conclusions:FF/UMEC/VI was well tolerated in Korean patients with asthma or COPD, with no new safety concerns identified. In COPD, within-patient improvement was observed in clinical outcomes post-administration. These results support continued FF/UMEC/VI use in real-world clinical practice in Korea.
Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is the standard minimally invasive method for mediastinal staging in non-small cell lung cancer. As the tumor, node, metastasis (TNM) classification evolves with more refined prognostic stratification of N2 substages, accurate mediastinal evaluation has become increasingly critical. Beyond conventional staging, recent advances have significantly expanded the clinical utility of EBUS-TBNA. This review explores six key areas of development: evidence supporting systematic over targeted mediastinal sampling and the potential to omit confirmatory mediastinoscopy after negative EBUS-TBNA; the role of endoscopic ultrasound in accessing paraesophageal and inferior mediastinal stations; expanded procedural capabilities with third-generation thin scope EBUS; novel tissue acquisition devices, including the 19-gauge needle, mini forceps, and mediastinal cryobiopsy; considerations for tissue adequacy in next-generation sequencing; and image-based adjunctive tools such as elastography and artificial intelligence-driven sonographic analysis. Collectively, these developments underscore the growing role of EBUS-TBNA as a comprehensive diagnostic platform in thoracic oncology, extending its utility from mediastinal staging to peripheral lesion access, molecular profiling, and image-guided decision support.
Biologic and targeted small-molecule therapies have revolutionized the management of severe asthma by specifically targeting key inflammatory pathways. These advances have led to significant reductions in exacerbations, improved lung function, and decreased dependence on corticosteroids. However, a substantial number of patients still experience breakthrough exacerbations and inadequate disease control, indicating that there are residual inflammatory mechanisms beyond the classical type-2 pathways. Current biologics that target immunoglobulin E, interleukin-5, interleukin-4 receptor alpha, and thymic stromal lymphopoietin show efficacy in biomarker-defined populations. Yet, their clinical benefits are closely tied to baseline type-2 biomarkers, and they often fall short for patients with non-type-2 or mixed inflammatory phenotypes. Emerging evidence from transcriptomic and clinical studies suggests that factors such as epithelial dysfunction, innate immune activation, and tissue repair pathways contribute to ongoing disease instability, even with targeted cytokine blockade. These insights have spurred the development of new therapeutic strategies, including biologics aimed at upstream epithelial alarmins like interleukin-33, oral small-molecule inhibitors such as Bruton tyrosine kinase inhibitors, lineage-directed eosinophil-suppressing agents, inhaled biologics, and nanobody-based therapies. Additionally, long-acting and ultra- long-acting biologics are designed to enhance treatment durability and adherence, while bispecific antibodies integrate both upstream and downstream inflammatory inhibition into a single molecular construct. These advancements signify a shift towards broader and more sustained modulation of inflammatory pathways. Future progress in asthma treatment will hinge on integrating insights from epithelial biology, refining biomarker- guided patient selection, and developing multispecific and upstream-targeting therapies to address persistent disease heterogeneity and improve long-term clinical outcomes.
BACKGROUND:With the increasing use of linezolid for the treatment of drug-resistant tuberculosis, concerns have emerged regarding serious adverse effects, including optic neuritis. To systematically review the available evidence on the incidence of optic neuritis reported in the cohort, its onset, linezolid doses and duration, spectrum, management approaches, and outcomes across case reports and series studies. METHODS:A systematic review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines after registration in International Prospective Register of Systematic Reviews (PROSPERO; CRD420251108339). We searched PubMed, EMBASE, and Scopus. Eligible studies included case reports, case series, and cohort studies of patients with tuberculosis who developed optic neuritis while receiving linezolid. Data were extracted independently by two reviewers, and methodological quality was assessed using a validated tool for evaluating case reports and case series. Results were synthesized narratively with descriptive statistics. RESULTS:Nineteen case reports and case series, 35 cohort studies, and safety data from five randomized controlled trials were included. Most reported cases originated from India (61.6%), with a mean age of 30.6±13.0 years; 65.4% were male. Linezolid was administered at 600 mg/day in nearly 90% of cases, with a median exposure of 7 months. Visual symptoms were typically painless and bilateral. After discontinuation of linezolid, more than half of the patients achieved complete visual recovery, while 34.6% experienced residual visual impairment. Across cohort studies, the incidence of optic neuritis ranged from 0.47% to 30%, with higher rates observed in smaller studies from a single country and among patients with a low body mass index. CONCLUSION:This infrequent but clinically significant complication requires early recognition, prompt drug withdrawal, and routine ophthalmological monitoring.
Precision medicine aims to define subtypes of a heterogeneous disease, which can lead to more specific diagnosis, prognosis, and/or treatment. Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease and therefore appropriate for a precision medicine approach. The idea of COPD heterogeneity has been proposed for decades, initially with subtypes of emphysema and chronic bronchitis. Modern approaches include the use of chest computed tomography (CT) scan imaging and omics biomarkers. One path forward is to start by identifying a clinical question, then try to understand the epidemiology, to describe clinical phenotypes and disease subtypes. One can then incorporate omics biomarkers to arrive at an endotype, a subtype with a shared biologic mechanism. Eosinophilic COPD and alpha-1 antitrypsin deficiency-related emphysema are endotypes that already have specific therapies. Subtypes such as patients with frequent exacerbations can be targeted with several treatments, but multiple biological processes are likely to be important. This review will highlight these approaches, using examples such as airway-predominant COPD, frequent exacerbations, and asthma-COPD overlap. These investigations have been conducted in large observational studies, including the multi-center US Genetic Epidemiology of COPD Study (COPDGene). The analyses have leveraged the wealth of data in COPDGene, including clinical information, pulmonary function tests, chest CT scans, and multi-omics such as genetics, RNA-sequencing, and proteomics. Despite these advances, there are many challenges for COPD precision medicine, such as the requirement for large studies with longitudinal outcomes and available biospecimens. Clinical trials of targeted therapies will be needed for the ultimate application of precision medicine in COPD.
