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Purpose: Long-term data are limited on the safety and efficacy of dupilumab in patients with uncontrolled, moderate-to-severe asthma from Korea. The current subgroup analysis was designed to evaluate the long-term safety and efficacy of dupilumab in patients enrolled from Korean centers in the parent studies (phase 2b and QUEST) and who participated in the TRAVERSE open-label extension (OLE) study., Methods: TRAVERSE was a global, multicenter, OLE study that assessed the safety and efficacy of dupilumab 300 mg every 2 weeks for up to 96 weeks in patients (n = 2,282) with uncontrolled, moderate-to-severe asthma who completed prior dupilumab asthma clinical trials. The primary outcome was the incidence of any treatment-emergent adverse events (TEAEs); the secondary outcomes included annualized severe exacerbation rate, pre-bronchodilator forced expiratory volume in 1 second (pre-BD FEV1), and 5-item Asthma Control Questionnaire (ACQ-5) score., Results: Safety outcomes were consistent with the parent studies and the overall TRAVERSE population; out of 74 patients, 70 experienced ≥ 1 TEAE, and 6 (8.1%) discontinued because of adverse events. During the treatment period, the unadjusted annualized severe exacerbation rate was low (0.470). Improvement in pre-BD FEV1 was seen as early as Week 2 with a mean change from the parent study baseline (PSBL), standard deviation (SD) of 0.42 L (0.47), which was sustained until Week 96. Mean change from PSBL (SD) in ACQ-5 score was -1.32 (0.76) at Week 48., Conclusions: This subgroup analysis of TRAVERSE showed the long-term safety and efficacy of dupilumab in patients with uncontrolled, moderate-to-severe asthma enrolled from Korean centers., Trial Registration: ClinicalTrials.gov Identifier: NCT02134028., Competing Interests: Chin Kook Rhee, Heung-Woo Park, and You Sook Cho are on the advisory panel on Sanofi, Korea; Hayeon Noh and Jerome Msihid are employees of Sanofi and may hold stocks or stock options in the company. Heung-Woo Park serves as a deputy editor for the Allergy, Asthma & Immunology Research journal and recuses himself from the editorial decisions on this manuscript. Jung-Won Park and You Sook Cho serve as editorial board members for the Allergy, Asthma & Immunology Research journal and recuse themselves from the editorial decisions on this manuscript., (Copyright © 2024 The Korean Academy of Asthma, Allergy and Clinical Immunology • The Korean Academy of Pediatric Allergy and Respiratory Disease.)

Purpose: Severe asthma is associated with high morbidity and healthcare utilization; however, treatment options for these patients are limited. This study aimed to determine the therapeutic effects of biologics in clinical practice., Methods: This multicenter, retrospective cohort study included 136 patients who received biologics for at least 4 months between September 2017 and July 2022 at 25 medical centers affiliated with the Korean Severe Asthma Registry (KoSAR). The study evaluated the treatment effects, including acute exacerbation rates, maintenance of oral corticosteroid dosages, lung function, quality of life, blood eosinophil count, and fractional exhaled nitric oxide (FeNO) levels, by comparing measurements before and after 4 months of biologic treatment. Responses for each medication was evaluated based on the Global Evaluation of Treatment Effectiveness score, and any adverse reactions were summarized., Results: With the administration of biologics over the course of 4 months, there was a reduction in asthma acute exacerbations, a significant improvement in lung function, and a significant decrease in daily maintenance dose of oral steroid. Blood eosinophil counts decreased in the mepolizumab and reslizumab groups, while FeNO levels decreased only in the dupilumab group. The Asthma Control Test, Quality of Life Questionnaire for Adult Korean Asthmatics, and the EuroQol-visual analogue scale scores showed a significant improvement. Most patients (80.15%) responded to the biologic treatment. Meanwhile, non-responders often had chronic rhinosinusitis as a comorbidity, exhibited lower lung function, and required higher doses of oral steroids. No severe adverse events were reported., Conclusions: Biologics are highly effective in Korean patients with Type 2 severe asthma, significantly reducing acute exacerbation rates and doses of oral corticosteroids, while also improving lung function. Therefore, it seems beneficial to administer biologics without any restrictions to patients exhibiting Type 2 severe asthma., Competing Interests: There are no financial or other issues that might lead to conflict of interest., (Copyright © 2024 The Korean Academy of Asthma, Allergy and Clinical Immunology • The Korean Academy of Pediatric Allergy and Respiratory Disease.)

Purpose: Few studies have compared the clinical characteristics of severe asthma (SA) in elderly patients compared to that in nonelderly patients., Methods: We analyzed data from the Korean SA Registry, a nationwide, real-world observational study of SA in Korea. The baseline clinical characteristics, disease control status, and medication use of the patients were compared between elderly (≥ 65 years) and nonelderly groups., Results: Of the 864 patients with SA, 260 (30.1%) were in the elderly group. The elderly group had lower atopy rate, but had higher prevalence of chronic obstructive pulmonary disease (COPD), hypertension, and osteoporosis than did the nonelderly group. The elderly group had a lower rate of type 2 inflammation and lower levels of forced expiratory volume in 1 second (FEV1) (% predicted) and FEV1/forced vital capacity ratio than did the nonelderly group ( P < 0.05 for all). However, asthma symptom scores and the frequency of asthma exacerbation were not significantly different between the 2 groups. Of controller medications, biologics were less frequently used in the elderly group ( P < 0.05 for all)., Conclusions: SA in the elderly is characterized by lower lung function, less type 2-low airway inflammation, and comorbidity with COPD. These findings are being taken into consideration in the management of elderly patients with SA in real-world clinical practice., Competing Interests: There are no financial or other issues that might lead to conflict of interest., (Copyright © 2024 The Korean Academy of Asthma, Allergy and Clinical Immunology • The Korean Academy of Pediatric Allergy and Respiratory Disease.)

Purpose: Staphylococcus aureus enterotoxin-specific immunoglobulin E (SE-sIgE) sensitization tends to increase with age and is known to be associated with asthma and severity in older adults. However, the long-term impact of SE-sIgE in the elderly remains unknown. This study aimed to examine the relationships between SE-sIgE and fixed airflow obstruction (FAO) in a cohort of elderly asthmatics., Methods: A total of 223 elderly asthmatics and 89 controls were analyzed. Patients were assessed for demographics, history of chronic rhinosinusitis (CRS), asthma duration, acute exacerbation frequency, and lung function at baseline and then were prospectively followed up for 2 years. Serum total IgE and SE-sIgE levels were measured at baseline. Airflow obstruction was defined as forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) ratio < 0.7 at baseline and FAO was defined as FEV1/FVC ratio < 0.7 over the 2-year follow-up., Results: At baseline, the prevalence of airflow obstruction was 29.1%. Patients with airflow obstruction were significantly more likely to be male, and have a positive smoking history, comorbid CRS, and higher levels of SE-sIgE than those without airflow obstruction. Multivariate logistic regression analysis showed that airflow obstruction was significantly associated with current smoking and SE-sIgE sensitization at baseline. After the 2-year follow-up, baseline SE-sIgE sensitization was consistently related to FAO. Meanwhile, the number of exacerbations per year was significantly correlated with SE-sIgE levels., Conclusions: Baseline SE-sIgE sensitization was significantly associated with the number of asthma exacerbations and FAO after the 2-year follow-up in elderly asthmatics. These findings warrant further investigation of the direct and mediating roles of SE-sIgE sensitization on airway remodeling., Competing Interests: There are no financial or other issues that might lead to conflict of interest., (Copyright © 2023 The Korean Academy of Asthma, Allergy and Clinical Immunology • The Korean Academy of Pediatric Allergy and Respiratory Disease.)

The aging lung undergoes structural changes, immunosenescence, and inflammation, rendering the elderly more susceptible to developing obstructive airway disease. Thus, asthma in those of chronological age ≥ 65 years is not rare. Elderly asthma (EA) imposes considerable burdens in terms of mortality and morbidity, and expenditure. However, clinicians lack knowledge of EA and thus often prescribe inappropriate management. In this review, we ask 3 key questions frequently encountered during EA diagnosis and treatment: 1) Is EA different?; 2) How can we appropriately diagnose EA?; 3) Are there management strategies specific to EA? Based on recent studies, we provide tentative answers as follows: 1) late-onset EA differs in clinical features and pathogenetic mechanisms from non-EA, and thus further phenotypic and endotypic characterization of EA is needed; 2) both over- and under-diagnosis of asthma in the elderly can be reduced if the objective diagnostic tests are appropriately performed; 3) cautious prescription of ICS to selected EA patients should be encouraged, and a multifaceted approach which involves increasing medical awareness and inhaler use proficiency and adherence, seeking the assistance of caregivers, and correcting micronutrient deficiencies is required to reduce acute exacerbations in EA patients., Competing Interests: There are no financial or other issues that might lead to a conflict of interest., (Copyright © 2023 The Korean Academy of Asthma, Allergy and Clinical Immunology • The Korean Academy of Pediatric Allergy and Respiratory Disease.)

Purpose: To assess the effect of dupilumab on the annualized severe exacerbation rates, change in forced expiratory volume at first second (FEV1), overall asthma control and health-related quality of life in Korean patients from the LIBERTY ASTHMA QUEST study., Methods: Of the 1,902 patients enrolled in the LIBERTY ASTHMA QUEST study, a phase-3, randomized, double-blind, placebo-controlled, parallel-group study on dupilumab, 74 (4%) were Korean. The patients were randomly assigned to 4 treatment groups (2:2:1:1). The sub-analysis reported herewith was performed with the pooled groups of dupilumab and placebo from the 4 original treatment groups in the LIBERTY ASTHMA QUEST study. The efficacy endpoints were annualized rate of severe exacerbation events during the 52-week study period and changes from baseline in pre-bronchodilator FEV1 in week 12. Asthma control, asthma quality of life and the effect of treatment on the levels of type 2 inflammatory biomarkers were assessed. The safety profile was also evaluated., Results: In Korean patients, annualized severe exacerbation rates were reduced with dupilumab (n = 49) compared to placebo (n = 25) (0.259 vs 1.942) during the 52-week treatment period. The relative risk reduction with dupilumab was 87% ( P < 0.001). Improvements in pre-bronchodilator FEV1 (mean difference of 0.24 L, P = 0.021) were observed in week 12 in dupilumab-treated patients. Additionally, improvements in asthma control and asthma-related quality of life were observed; the FeNO and serum immunoglobulin E levels were reduced. The incidence of adverse events and serious adverse events was comparable between the dupilumab and placebo group. A total of 11 patients from the dupilumab group reported 63 injection site reactions., Conclusions: Dupilumab, as an add-on therapy in severe asthma, is efficacious and has an acceptable safety profile in Korean patients., Trial Registration: ClinicalTrials.gov Identifier: NCT02414854., Competing Interests: Chin Kook Rhee, Heung-Woo Park, You Sook Cho are on advisory panel on Sanofi Aventis Korea Jung-Won Park has no conflict of interest to declare., (Copyright © 2022 The Korean Academy of Asthma, Allergy and Clinical Immunology • The Korean Academy of Pediatric Allergy and Respiratory Disease.)

Purpose: Although asthma treatment guidelines recommend regular inhaled medication, real-world treatment patterns and outcomes in South Korea have not been examined. We examined real-world treatment patterns and outcomes among patients treated for asthma in South Korea., Methods: This retrospective cohort study utilized data from the South Korean National Health Insurance database (2013-2016). Newly treated patients with asthma aged ≥18 years without history of chronic obstructive pulmonary disease were included. Initial and maintenance medication prescriptions were examined. Treatment discontinuation and switch were described. Asthma exacerbation rates, poor asthma control, and healthcare resource utilization (HRU) were compared between maintenance treatment groups (inhaled versus oral) using adjusted incidence rate ratios (aIRR) and hazard ratios (aHR)., Results: Overall, 1,054,707 patients initiated any asthma medication; 37,868 patients initiated inhaled (n = 9,983, 26.4%) or oral (n = 27,885, 73.6%) maintenance medication. More patients initiating inhaled versus oral asthma medication discontinued treatment within 12 months (94.4% vs. 86.3%; P < 0.0001). Patients treated with inhaled and oral medication switched treatment (2.5% and 2.3%; P = 0.4160, respectively). Patients initiating inhaled medication had significantly lower rates of asthma exacerbation (aIRR, 0.52; 95% CI, 0.39-0.69), lack of asthma control (aHR, 0.55; 95% CI, 0.48-0.62; P < 0.0001), all-cause and asthma-related HRU versus oral medication., Conclusions: Despite current asthma guidelines, more patients in South Korea were prescribed oral than inhaled medications, resulting in suboptimal asthma management and increased HRU. This study highlights the need to reduce oral corticosteroid prescriptions for optimized treatment in asthma management., Competing Interests: N-KC, M-SK, C-HL, BRY, JL and H-WP have received research funds from GlaxoSmithKline plc. SS is an employee of and stock/shareholder in GlaxoSmithKline plc. DH was an employee of and stock/shareholder in GlaxoSmithKline plc. at the time of the study. WYC, PB, MSD and CK are employees of Analysis Group Inc., a consulting company that received research funds from GlaxoSmithKline plc. to conduct this study., (Copyright © 2022 The Korean Academy of Asthma, Allergy and Clinical Immunology • The Korean Academy of Pediatric Allergy and Respiratory Disease.)

The Working Group on Severe Asthma of the Korean Academy of Allergy and Clinical Immunology recently published an expert opinion paper on the management of severe asthma in Korea. When developing a consensus, the working group encountered several diagnostic and treatment issues and decided to perform a questionnaire survey of Korean specialists with regard to severe asthma. An e-mail with a uniform resource locator link to the questionnaire was sent to 121 asthma specialists, of whom 44.6% responded. The most commonly accepted definitions of severe asthma were a history of fatal exacerbation or an asthma-triggered need for mechanical ventilation, 3-4 oral corticosteroid (OCS) bursts/year, and maintenance of OCS therapy for 3-6 months per year. Before diagnosing severe asthma, most physicians contemplate chest computed tomography, seek to control chronic rhinosinusitis, and consider poor inhaler compliance. For patients with uncontrolled severe asthma accompanied by type 2 (T2)-high inflammation, most biologics available in Korea were considered appropriate, but gaps were apparent in terms of T2-low asthma treatments. These findings about specialist perception of diagnosis and treatment of severe asthma will inform the use of emerging new drugs and facilitate personalized therapy., Competing Interests: There are no financial or other issues that might lead to a conflict of interest., (Copyright © 2021 The Korean Academy of Asthma, Allergy and Clinical Immunology · The Korean Academy of Pediatric Allergy and Respiratory Disease.)

Severe asthma (SA) presents in about 3%-5% of adult asthmatics and is responsible for over 60% of asthma-related medical expenses, posing a heavy socioeconomic burden. However, to date, a precise definition of or clear diagnostic criteria for SA have not been established, and therefore, it has been challenging for clinicians to diagnose and treat this disease. Currently, novel biologics targeting several molecules, such as immunoglobulin E, interleukin (IL)5, and IL4/IL13, have emerged, and many new drugs are under development. These have brought a paradigm shift in understanding the mechanism of SA and have also provided new treatment options. However, we need to agree on a precise definition of and its diagnostic criteria for SA. Additionally, it is necessary to explain the diagnostic criteria and to summarize current standard and additional treatment options. This review is an experts' opinion on SA from the Korean Academy of Asthma, Allergy, and Clinical Immunology, the Working Group on Severe Asthma, and aims to provide a definition of and diagnostic criteria for SA, and propose future direction for SA diagnosis and management in Korea., Competing Interests: There are no financial or other issues that might lead to conflict of interest., (Copyright © 2020 The Korean Academy of Asthma, Allergy and Clinical Immunology · The Korean Academy of Pediatric Allergy and Respiratory Disease.)

Purpose: Acute exacerbation (AE) is an important domain of asthma management and may be related with ineffective response to corticosteroid. This study aimed to find mechanisms of AE using genome-wide gene expression profiles of blood cells from asthmatics and its perturbation by in vitro dexamethasone (Dex)-treatment., Methods: We utilized lymphoblastoid B cells from 107 childhood asthmatics and peripheral blood mononuclear cells from 29 adult asthmatics who were treated with inhaled corticosteroids. We searched for a preserved co-expression gene module significantly associated with the AE rate in both cohorts and measured expression changes of genes belong to this module after Dex-treatment., Results: We identified a preserved module composed of 77 genes. Among them, expressions of 2 genes ( EIF2AK2 and NOL11 ) decreased significantly after Dex-treatment in both cohorts. EIF2AK2 , a key gene acting antiviral defense mechanism, showed significantly higher expressions in asthmatics with AE. The protein repair pathway was enriched significantly in 64 genes which belong to the preserved module but showed no expression differences after Dex-treatment in both cohorts. Among them, MSRA and MSRB2 may play key roles by controlling oxidative stress., Conclusions: Many genes belong to the AE rate-associated and preserved module identified in blood cells from childhood and adults asthmatics showed no expression changes after in vitro Dex-treatment. These findings suggest that we may need alternative treatment options to corticosteroids to prevent AE. EIF2AK2 , MSRA and MSRB2 expressions on blood cells may help us select AE-susceptible asthmatics and adjust treatments to prevent AE., Competing Interests: There are no financial or other issues that might lead to conflict of interest., (Copyright © 2020 The Korean Academy of Asthma, Allergy and Clinical Immunology · The Korean Academy of Pediatric Allergy and Respiratory Disease.)

The transcriptome represents the complete set of RNA transcripts that are produced by the genome under a specific circumstance or in a specific cell. High-throughput methods, including microarray and bulk RNA sequencing, as well as recent advances in biostatistics based on machine learning approaches provides a quick and effective way of identifying novel genes and pathways related to asthma, which is a heterogeneous disease with diverse pathophysiological mechanisms. In this manuscript, we briefly review how to analyze transcriptome data and then provide a summary of recent transcriptome studies focusing on asthma pathogenesis and asthma drug responses. Studies reviewed here are classified into 2 classes based on the tissues utilized: blood and airway cells., Competing Interests: There are no financial or other issues that might lead to conflict of interest., (Copyright © 2020 The Korean Academy of Asthma, Allergy and Clinical Immunology · The Korean Academy of Pediatric Allergy and Respiratory Disease.)

Purpose: Asthma in the elderly (EA; ≥ 65 years of age) is increasing, adding a heavy socioeconomic burden to the healthcare system. However, little is known about risk factors associated with acute exacerbations in EA patients. The objective of this study was to investigate risk factors for acute exacerbation in EA compared to non-elderly asthma (NEA)., Methods: We combined data from 3 adult asthma cohorts under a unified protocol and database. Asthmatic patients with regular follow-up during a 1-year period were selected from the cohorts to identify the risk factors predicting acute exacerbations in EA compared to NEA., Results: We selected a total of 1,086 patients from the merged cohort. During the observation period, 503 and 583 patients were assigned to the EA and NEA groups, respectively. The exacerbation rate was 31.0% in the EA and 33.2% in the NEA group. Multivariate logistic regression analysis revealed fixed airway obstruction, chronic rhinosinusitis (CRS), and male sex as independent risk factors for exacerbation in the EA group. In the NEA group, exacerbation increased along with an increase in eosinophil count. Bayesian analysis of the interactions among clinical factors revealed that forced expiratory volume in 1 second/forced vital capacity was directly related to exacerbation in the EA group, and eosinophil count was related to exacerbation in the NEA group., Conclusions: We suggest that fixed airway obstruction and CRS as the important clinical factors predicting acute exacerbations in EA, whereas in NEA, eosinophil count was the strong predictor of exacerbation., Competing Interests: There are no financial or other issues that might lead to conflict of interest, (Copyright © 2020 The Korean Academy of Asthma, Allergy and Clinical Immunology · The Korean Academy of Pediatric Allergy and Respiratory Disease.)

Background: Elderly asthma (EA) is increasing, but the pathogenesis is unclear. This study aimed to identify EA-related biological pathways by analyzing genome-wide gene expression profiles in sputum cells., Methods: A total of 3,156 gene probes with significantly differential expressions between EA and healthy elderly controls were used for a hierarchical clustering of genes to identify gene clusters. Gene set enrichment analysis provided biological information, with replication from Gene Expression Omnibus expression profiles., Results: Fifty-five EA patients and 10 elderly control subjects were enrolled. Two distinct gene clusters were found. Cluster 1 (n = 35) showed a lower eosinophil proportion in sputum and less severe airway obstruction compared to cluster 2 (n = 20). The replication data set also identified 2 gene clusters (clusters 1' and 2'). Among 5 gene sets significantly enriched in cluster 1 and 3 gene sets significantly enriched in cluster 2, we confirmed that 2 were significantly enriched in the replication data set (OXIDATIVE&#95;PHOSPHORYLATION gene set in cluster 1 and EPITHELIAL MESENCHYMAL TRANSITION gene set in cluster 2')., Conclusions: The findings of 2 distinct gene clusters in EA and different biological pathways in each gene cluster suggest 2 different pathogenesis mechanisms underlying EA., Competing Interests: There are no financial or other issues that might lead to conflict of interest., (Copyright © 2019 The Korean Academy of Asthma, Allergy and Clinical Immunology · The Korean Academy of Pediatric Allergy and Respiratory Disease.)

Purpose: Although mild to moderate asthma is much more common, the morbidity and mortality of severe asthma are much higher. This study was performed to identify and analyze the clinical characteristics of severe asthma in Korea., Methods: We registered patients with severe refractory asthma into the Severe Asthma Registry supported by the Severe Asthma Work Group of the Korean Academy of Asthma, Allergy and Clinical Immunology. Patients were enrolled since 2010 from the 15 university hospitals nationwide in Korea. Severe asthma was defined according to modified European Respiratory Society/American Thoracic Society criteria. Information on demographics, medical history, pulmonary function tests and skin prick tests was collected; the clinical characteristics of severe asthmatics were analyzed from the collected data., Results: A total of 489 patients were enrolled with a mean age of 62.3; 45% are male. Sixty percent of patients received Global Initiative for Asthma step 4 treatment, and 30% received step 5 treatment. The most common comorbidities were allergic rhinitis (58.7%). Aspirin hypersensitivity was observed in 14.0%. Approximately half (53.9%) are non-smokers. Atopy was proven in 38.5% of the patients. Regarding asthma medications, inhaled corticosteroids and long-acting β-agonist combination inhalers were most commonly prescribed (96.5%), followed by leukotriene antagonists (71.0%). A recombinant anti-immunoglobulin E monoclonal antibody (omalizumab) has been used in 1.8% of the patients. The mean forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1) and FEV1/FVC were 78.7%, 67.5% and 67.9% of predicted values, respectively. The mean Asthma Control Test and quality of life questionnaire scores were 16.5 out of 25 and 59.5 out of 85, respectively., Conclusions: The baseline characteristics of severe asthma patients in the Korea Severe Asthma Registry were analyzed and reported for the first time. With this cohort, further prospective studies should be performed to search for ways to improve management of severe refractory asthma., Competing Interests: There are no financial or other issues that might lead to conflict of interest., (Copyright © 2019 The Korean Academy of Asthma, Allergy and Clinical Immunology · The Korean Academy of Pediatric Allergy and Respiratory Disease.)

Purpose: Human leukocyte antigen (HLA) has been recognized as the most important genetic risk factor for severe cutaneous adverse drug reactions (SCARs) caused by certain drugs. However, cumulated observations suggest the presence of genetic risk factors for SCARs other than drug-specific HLA. We aimed to identify a common genetic risk factor of SCARs across multiple drugs., Methods: We performed 2 independent genome-wide association studies (GWASs). A total of 68 and 38 subjects with a diagnosis of SCAR were enrolled in each GWAS. Their allele frequencies were compared to those of healthy subjects in Korea., Results: No single nucleotide polymorphism (SNP) with genome-wide significance was found in either GWAS. We next selected and annotated the 200 top-ranked SNPs from each GWAS. These 2 sets of annotated genes were then entered into the web interface of ConsensusPathDB for a pathway-level analysis. The Fas signaling pathway was significantly over-represented in each gene set from the 2 GWASs., Conclusions: Our observations suggest that the Fas signaling pathway may be a common genetic risk factor for SCARs across multiple drugs., Competing Interests: There are no financial or other issues that might lead to conflict of interest., (Copyright © 2018 The Korean Academy of Asthma, Allergy and Clinical Immunology · The Korean Academy of Pediatric Allergy and Respiratory Disease.)

Purpose: Severe asthma and asthma-chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS) are difficult to control and are often associated with poor clinical outcomes. However, much is not understood regarding the diagnosis and treatment of severe asthma and ACOS. To evaluate the current perceptions of severe asthma and COPD among asthma and COPD specialists, we designed an e-mail and internet-based questionnaire survey., Methods: Subjects were selected based on clinical specialty from among the members of the Korean Academy of Asthma, Allergy and Clinical Immunology and the Korean Academy of Tuberculosis and Respiratory Diseases. Of 432 subjects who received an e-mail invitation to the survey, 95 subjects, including 58 allergists and 37 pulmonologists, responded and submitted their answers online., Results: The specialists estimated that the percentage of severe cases among total asthma patients in their practice was 13.9%±11.0%. Asthma aggravation by stepping down treatment was the most common subtype, followed by frequent exacerbation, uncontrolled asthma despite higher treatment steps, and serious exacerbation. ACOS was estimated to account for 20.7% of asthma, 38.0% of severe asthma, and 30.1% of COPD cases. A history of smoking, persistently low forced expiratory volume in 1 second (FEV1), and low FEV1 variation were most frequently classified as the major criteria for the diagnosis of ACOS among asthma patients. Among COPD patients, the highly selected major criteria for ACOS were high FEV1 variation, positive bronchodilator response, a personal history of allergies and positive airway hyperresponsiveness. Allergists and pulmonologists showed different assessments and opinions on asthma phenotyping, percentage, and diagnostic criteria for ACOS., Conclusions: Specialists had diverse perceptions and clinical practices regarding severe asthma and ACOS patients. This heterogeneity must be considered in future studies and strategy development for severe asthma and ACOS., Competing Interests: There are no financial or other issues that might lead to conflict of interest., (Copyright © 2018 The Korean Academy of Asthma, Allergy and Clinical Immunology · The Korean Academy of Pediatric Allergy and Respiratory Disease.)

The aim of this study was to examine the daily practice patterns of Symbicort® Maintenance and Reliever Therapy (SMART) in Korean asthmatic patients and to analyze clinical signs related to overuse. This study used an observational, multicenter, noninterventional, prospective, uncontrolled design for examining asthmatic patients prescribed SMART to assess the frequency and pattern of Symbicort® usage as a maintenance and reliever medication. The characteristics of patients showing signs of overuse (frequency of inhalation: 8 or more times per day) were also analyzed. Among the 1,518 patients analyzed, 1,292 (85.1%) completed the trial. The number of mean inhalations per day was 2.14±1.15; the number of patients who had at least 1 as needed usage (PRN) inhalation per day was 843 (55.5%); the mean frequency of PRN use was 0.25±0.67 inhalations per day. The number of patients who overused for at least 1 day was 260 (17.1%). In particular, young patients, patients with limited physical activity, and patients with nocturnal symptoms demonstrated high frequency of overuse. The frequency of overuse during SMART was not high in Korean asthmatic patients and the asthma status of follow-up outpatients improved overall. However, there is a need for careful education targeted toward younger patients, patients with limited physical activity, and patients with nocturnal symptoms owing to their tendency to frequently overuse., Competing Interests: There are no financial or other issues that might lead to conflict of interest., (Copyright © 2018 The Korean Academy of Asthma, Allergy and Clinical Immunology · The Korean Academy of Pediatric Allergy and Respiratory Disease.)

Purpose: Inhalant allergen sensitization is one of the major factors involved in the pathogenesis of allergic respiratory diseases. However, the sensitization is determined by interactions between genetic and environmental factors. Thus, testing panels of inhalant allergens may differ among geographical areas. Here we aimed to determine 10 common inhalant allergens in Korean adult patients with suspected respiratory allergies and to examine the variation between different geographical locations., Methods: A total of 28,954 patient records were retrieved for retrospective analysis, from 12 referral allergy clinics located in 9 different areas. Inclusion criteria were Korean adults (≥18 years old) who underwent the inhalant allergen skin prick test for suspected history of respiratory allergy. The primary outcome was inhalant allergen skin prick response. Demographic and clinical information were also collected. Positive skin prick responses to allergens were defined as allergen-to-histamine wheal ratio ≥1. Based on skin test results, the most prevalent aeroallergens were determined., Results: The overall prevalence of allergic sensitization was 45.3%. Dermatophagoides farinae and Dermatophagoides pteronyssinus were the most commonly sensitized allergens. Other common inhalant allergens were cat epithelium (8.1%), birch (7.7%), mugwort (6.9%), alder (6.7%), hazel (6.7%), beech (6.7%), oak (6.6%), and Tyrophagus putres (6.2%), in decreasing order frequency. These 10 inhalant allergens explained 90% of inhalant allergen sensitization in the study participants. However, distinct patterns of the 10 inhalant sensitization were observed in patients living in Chungnam and Jeju. American cockroach, Gernam cockroach, and Trichophyton metagrophytes were unique in Chungnam. Orchard, Japanese cedar, and Velvet were unique in Jeju., Conclusions: The present analysis suggests a panel of 10 most common inhalant allergens in Korean adult patients with suspected respiratory allergies, which explained 90% of inhalant allergen sensitization. This panel can be utilized as a practical and convenient tool for primary practice and epidemiological surveys of respiratory allergic diseases., Competing Interests: There are no financial or other issues that might lead to conflict of interest., (Copyright © 2017 The Korean Academy of Asthma, Allergy and Clinical Immunology · The Korean Academy of Pediatric Allergy and Respiratory Disease)

Asthma exacerbation (AE) usually denotes worsening of asthma symptoms that requires intense management to prevent further deterioration. AE has been reported to correlate with clinical and demographic factors, such as race, gender, and treatment compliance as well as environmental factors, such as viral infection, smoking, and air pollution. In addition, recent observations suggest that there are likely to be genetic factors specific to AE. Understanding genetic factors specific to AE is essential to develop therapy tailored for exacerbation-prone asthma. Here, we summarize the results of studies involving genetic risk factors for AE. To simplify and enhance understanding, we reviewed the studies according to the following categories: hypothesis-driven approaches, hypothesis-free approaches, gene-environment interactions, and pharmacogenetics., Competing Interests: There are no financial or other issues that might lead to conflict of interest., (Copyright © 2017 The Korean Academy of Asthma, Allergy and Clinical Immunology · The Korean Academy of Pediatric Allergy and Respiratory Disease.)

Purpose: Recent evidence suggests a global burden of chronic cough in general populations. However, the definitions vary greatly among epidemiological studies, and none have been validated for clinical relevance. We aimed to examine previous epidemiological definitions in detail and explore the operational characteristics., Methods: A systematic review was conducted for epidemiological surveys that reported the prevalence of chronic cough in general adult populations during the years 1980 to 2013. A literature search was performed on Pubmed and Embase without language restriction. Epidemiological definitions for chronic cough were classified according to their components, such as cutoff duration. Meta-analyses were performed for the male-to-female ratio of chronic cough prevalence to explore operational characteristics of epidemiological definitions., Results: A total of 70 studies were included in the systematic review. The most common epidemiological definition was identified as 'cough ≥3 months' duration without specification of phlegm (n=50); however, it conflicted with the cutoff duration in current clinical guidelines (cough ≥8 weeks). Meta-analyses were performed for the male-to-female ratio of chronic cough among 28 studies that reported sex-specific prevalence using the most common definition. The pooled male-to-female odds ratio was 1.26 (95% confidence interval 0.92-1.73) with significant heterogeneity (I²=96%, P<0.001), which was in contrast to clinical observations of female predominance from specialist clinics. Subgroup analyses did not reverse the ratio or reduce the heterogeneity., Conclusions: This study identified major issues in defining chronic cough in future epidemiological studies. The conflict between epidemiological and clinical diagnostic criteria needs to be resolved. The unexpected difference in the gender predominance between the community and clinics warrants further studies. Clinical validation of the existing definition is required.

Eosinophils have been reported to modulate T cell responses. Previously, we reported that high-mobility group box 1 protein (HMGB1) played a key role in the pathogenesis of asthma. This study was conducted to test our hypothesis that eosinophils could modulate T cell responses via HMGB1 in the pathogenesis of asthma characterized by eosinophilic airway inflammation. We performed in vitro experiments using eosinophils, dendritic cells (DCs), and CD4(+) T cells obtained from a murine model of asthma. The supernatant of the eosinophil culture was found to significantly increase the levels of interleukin (IL)-4 and IL-5 in the supernatant of CD4(+) T cells co-cultured with DCs. HMGB1 levels increased in the supernatant of the eosinophil culture stimulated with IL-5. Anti-HMGB1 antibodies significantly attenuated increases of IL-4 and IL-5 levels in the supernatant of CD4(+) T cells co-cultured with DCs that were induced by the supernatant of the eosinophil culture. In addition, anti-HMGB1 antibodies significantly attenuated the expressions of activation markers (CD44 and CD69) on CD4(+) T cells. Our data suggest that eosinophils modulate CD4(+) T cell responses via HMGB1 in the pathogenesis of asthma.

Nitric oxide (NO) is a biologic mediator of various physiologic functions. Recent evidence suggests the clinical utility of fractional exhaled NO (FeNO) as a biomarker for assessing asthma and other respiratory diseases. FeNO methodologies have been recently standardized by international research groups and subsequently validated in several Korean population studies. Normal ranges for FeNO have been reported for various ethnic groups, and the clinical utility has been widely evaluated in asthma and various respiratory diseases. Based on current evidence including most of Korean population data, this position paper aims to introduce the methodological considerations, and provide the guidance for the proper clinical application of FeNO measurements in Korean populations.

Purpose: Exhaled nitric oxide (NO) is a useful non-invasive biomarker for asthma diagnosis; however, the literature suggests that exhaled NO levels may be affected by demographic factors. The present analysis investigated determinant factors that present exhaled NO reference levels for Korean elderly adults., Methods: For reference levels, we analyzed the baseline data of healthy adult participants in the Ansung cohort. The fraction of exhaled NO (FeNO) was measured by NIOX MINO®. The characterization of the subjects was performed through structured questionnaires, spirometry, and methacholine challenge tests. To validate the diagnostic utility of the determined reference levels, asthma patients were recruited from medical institutions for FeNO measurement., Results: A total of 570 healthy subjects were analyzed (mean age, 59.9±12.3; male, 37.0%) for reference levels. FeNO levels significantly correlated with weight, height, body mass index, atopy, or forced expiratory volume in 1 second % predicted by simple linear regression analysis. Multiple linear regression analysis identified gender as an independent determinant for FeNO levels; subsequently, the reference values for FeNO were 18.2±10.6 ppb (5th to 95th percentile, 6.0 to 37.4 ppb) for males and 12.1±6.9 ppb (5th to 95th percentile, 2.5 to 27.0 ppb) for females. The diagnostic utility of FeNO reference levels was validated by receiver operating curve analysis (area under curve, 0.900 for males and 0.885 for females) for diagnosing asthma. The optimal cutoff values for the prediction of asthma were 30.5 ppb for males and 20.5 ppb for females., Conclusions: The current analysis presented reference ranges and the diagnostic utility of FeNO levels for asthma in Korean elderly adults.

Purpose: The present study aimed to examine the age and gender distributions among chronic cough patients referred to a tertiary cough clinic in Korea, and to investigate clinical factors related to the demographic findings., Methods: Study participants were unselectively recruited from adult chronic cough patients who attended the cough clinic for the first time during one year. To validate their representativeness, their age and gender distributions were compared to the entire chronic cough population, or with those presenting with other chronic disease. Data from the baseline investigations were analyzed to identify clinical factors related to the demographic findings., Results: A total of 272 chronic cough patients were included. They had a middle-aged female predominant feature (mean age: 52.8±15.7 years and female 69.1%). Their age and gender distributions were almost identical to the entire chronic cough population, but were distinct from patients with hypertension. Among clinical factors, the older female predominance was associated with enhanced capsaicin cough sensitivity, and also with the presence of 'cough by cold air' symptom. Allotussia and laryngeal paresthesia were highly common in chronic cough patients, affecting 94.8% and 86.8% of them, respectively., Conclusions: The present study demonstrated older female predominance among adult chronic cough patients attending a referral cough clinic in Korea. The demographic features were significantly associated with the capsaicin cough responses and also potentially with allotussia (particularly cold air as the trigger). These findings suggest a role of cough reflex sensitization in the pathophysiology of chronic cough in adults.

Purpose: Identification of tolerable alternative analgesics is crucial for management in nonsteroidal anti-inflammatory drug (NSAID)-sensitive patients. We investigated cross-reactivity of acetaminophen and celecoxib according to the type of aspirin/NSAID hypersensitivity and aimed to determine the risk factors for cross-intolerance., Methods: We retrospectively reviewed the medical records of patients intolerant to aspirin and NSAIDs who had undergone an acetaminophen and/or celecoxib oral provocation test. Aspirin/NSAID hypersensitivity was classified into 4 types according to a recently proposed classification: aspirin-exacerbated respiratory disease (AERD), aspirin-exacerbated chronic urticaria (AECU), aspirin-induced acute urticaria/angioedema (AIAU), and NSAID-induced blended reaction (NIRD)., Results: A total of 180 patients with hypersensitivity to aspirin and NSAIDs were enrolled; 149 acetaminophen provocation test results and 145 celecoxib provocation test results were analyzed. The overall cross-reaction rates to acetaminophen and celecoxib were 24.8% and 10.3%, respectively. There was a significant difference in the cross-reactivity to acetaminophen according to the type of NSAID hypersensitivity. Cross-reactivity to acetaminophen was highest in the AECU group (43.9%), followed by the AERD (33.3%), NIBR (16.7%), and AIAU (12.5%) groups. Underlying chronic urticaria was more prevalent in patients with cross-intolerance to both acetaminophen (P=0.001) and celecoxib (P=0.033). Intolerance to acetaminophen was associated with intolerance to celecoxib (P<0.001)., Conclusions: Acetaminophen and celecoxib may induce adverse reactions in a non-negligible portion of aspirin/NSAID-sensitive patients. Physicians should be aware of the possible cross-reactions of these alternative drugs and consider an oral challenge test to confirm their tolerability.

Purpose: Allergic asthma (AA) and rheumatoid arthritis (RA) are immune tolerance-related diseases, and immune tolerance is known to be influenced by costimulatory molecules. In this study, we sought to identify common genetic susceptibility in AA and RA., Methods: Two hundred cases of AA, 184 cases of RA, and 182 healthy controls were recruited at the Seoul National University Hospital, Seoul, Korea. Eight single nucleotide polymorphisms (SNPs) in five genes coding costimulatory molecules, namely, -318C>T, +49A>G, and 6230G>A in CTLA4, IVS3+17T>C in CD28, -3479T>G and I179V in CD86, -1C>T in CD40, and -3458A>G in CD40LG were scored, and genetic interactions were evaluated by multifactor dimensionality reduction (MDR) analysis., Results: MDR analysis revealed a significant gene-gene interaction between -3479T>G CD86 and -3458A>G CD40LG for AA. Subjects with the T/T genotype of -3479T>G CD86 and the A/A genotype of -3458A>G CD40LG were found to be significantly more likely to develop AA than those with the T/T genotype of -3479T>G CD86 and A/- genotype of -3458A>G CD40LG (adjusted OR, 6.09; 95% CI, 2.89-12.98; logistic regression analysis controlled by age). Similarly those subjects showed a significant risk of developing RA (adjusted OR, 39.35; 95% CI, 15.01-107.00, logistic regression analysis controlled by age)., Conclusions: Our findings suggest that a genetic interaction between CD86 and CD40LG favors the development of both AA and RA.

Purpose: This study evaluates offending allergens in patients with allergic rhinitis (AR) according to age that establish a minimal panel for skin prick test (SPT) allergens required to identify if a patient is sensitized., Methods: We retrospectively analyzed SPT results according to age to determine the minimum test battery panel necessary to screen at least 93%-95% of AR patients. Allergic skin tests (common airborne indoor and outdoor allergens) were performed on 7,182 patients from January 2007 to June 2011. All patients were classified into 9 groups according to age; subsequently, we investigated offending allergens by age group., Results: A total of 5,032 (70.1%) patients were found sensitized to at least one of the 55 aeroallergen extracts tested. The annual ranking of offending allergens was not significantly different from each other over the past 5 years. House dust mites (HDM) were the most prevalent allergens ranked from first to third for all 5 years. The allergens in the minimum test panel differed slightly among all age groups; in addition, the types of sensitized allergen sources were more diverse in the older versus younger age group. HDM covered a larger proportion of the sensitized allergens in the younger age group versus the older age group. Testing with 5 allergens (Dermatophagoides farinae, Tetranychus urticae, oak, mugwort and cockroach) adequately identified over 90% of the sensitized patients., Conclusions: A SPT with around 5-7 allergens adequately detected most of the sensitization in the majority of the age groups in Korea. However, this study suggests that physicians perform the SPT with appropriately selected allergens in each age category for the screening of AR.

Purpose: Sputum eosinophilia is observed frequently in patients with rhinitis. Sputum eosinophilia in patients with non-asthmatic allergic rhinitis has been suggested to be related to nonspecific airway hyperresponsiveness (AHR). However, the clinical significance of sputum eosinophilia in patients with non-asthmatic rhinitis without AHR has not been determined. We conducted a retrospective study examining the influence of sputum eosinophilia in patients with non-asthmatic rhinitis without AHR on pulmonary function and expression of fibrosis-related mediators., Methods: Eighty-nine patients with moderate-to-severe perennial rhinitis without AHR were included. All underwent lung function tests (forced expiratory volume in 1 second [FEV1] and forced vital capacity [FVC]), skin tests to inhalant allergens, methacholine bronchial challenge tests, and hypertonic saline-induced sputum to determine eosinophil counts. Sputum mRNA levels for transforming growth factor-β (TGF-β), matrix metalloproteinase-9 (MMP-9), and tissue inhibitor of metalloproteinase-1 (TIMP-1) were also examined. Patients were divided into two groups according to the presence of sputum eosinophilia (≥3%, eosinophilia-positive [EP] and <3%, eosinophilia-negative [EN] groups)., Results: FEV1 was significantly lower (P=0.04) and FEV1/FVC tended to be lower (P=0.1) in the EP group than in the EN group. In sputum analyses, the MMP-9 mRNA level (P=0.005) and the ratio of MMP-9 to TIMP-1 expression (P=0.01) were significantly higher in the EP group than in the EN group. There was no significant difference in TGF-β mRNA expression between the two groups., Conclusions: Sputum eosinophilia in patients with moderate-to-severe perennial rhinitis without AHR influenced FEV1 and the expression pattern of fibrosis-related mediators.

Purpose: Atopy is an important cause of asthma. Few data on the prevalence of atopy or comparisons with clinical characteristics of asthma in Korean patients have been published. We evaluated the effects of atopy on clinical profiles and airway inflammation in Korean asthmatics., Methods: We retrospectively enrolled 1,492 asthmatics from the Cohort for Reality and Evolution of Adult Asthma in Korea (COREA) cohort who had undergone skin prick tests for aeroallergens. The patients' clinical characteristics, lung function, PC20, and sputum and blood inflammatory cell counts were compared based on the presence or absence of atopy. Atopy was defined as one or more positive reactions (A/H ratio >1) on a skin prick test., Results: Among 11 aeroallergens, house dust mites (Dermatophagoides farinae and Dermatophagoides pteronyssinus) were the most prevalent cause of a positive skin prick test. As compared with non-atopic asthmatics, atopic asthmatics showed early onset of the disease. Atopic patients with asthma had a higher FEV1, FVC, and FEV1/FVC as compared with non-atopic patients with asthma. In addition, asthmatics without atopy had more uncontrolled asthma (P=0.001) and severe rhinitis (P<0.05) as compared with atopic asthmatics. Smoking, as measured in pack years, was higher in the non-atopic asthmatics than in the atopic asthmatics. The erythrocyte sedimentation rate was higher in non-atopic asthmatics than in the atopic asthmatics and patients with non-atopic asthma had a higher sputum neutrophil count than did those with atopic asthma., Conclusions: Our data indicate that atopic asthmatics had an early onset of disease and high IgE levels, while the non-atopic asthmatics had decreased lung function and a high sputum neutrophil count, suggesting that a different approach is needed to treat atopic asthma.

Purpose: Drug-induced liver injury (DILI) is the most common adverse drug reaction; however, it is not easily predicted. We hypothesize that DILI has a common genetic basis. Based on the findings of previous animal studies on toxic hepatitis, we selected the thioredoxin reductase 1 gene (TXNRD1) as a candidate marker of DILI for this genetic association study., Methods: Records from 118 patients with DILI were extracted from the database of the Adverse Drug Reaction Research Group in South Korea. Causative drugs included antituberculosis drugs (n=68, 57.6%), antibiotics (n=22, 18.6%), antiepileptic drugs (n=7, 5.9%), non-steroidal anti-inflammatory drugs (n=5, 4.2%), and others (n=16, 13.7%). Seven single nucleotide polymorphisms (SNPs) in TXNRD1 (rs10735393, rs4964287, rs4595619, rs10861201, rs11111997, rs4246270, and rs4246271) were scored in 118 DILI patients and in 120 drug-matched controls without liver injury., Results: No differences were found between the frequencies of any of the 7 SNPs in the cases and controls; however, a significant association was found between a TTA haplotype composed of rs10735393, rs4964287, and rs4595619 and DILI using an allele model (odds ratio, 1.79; 95% confidence interval, 1.18-2.73; P=0.008; Bonferroni corrected P=0.024)., Conclusions: These results suggest that genetic variations in TXNRD1 favor the development of DILI, although a larger confirmative study is needed.

Purpose: Allergic rhinitis is clinically defined as a disorder of the nose induced by IgE mediated inflammation after allergen exposure of the nasal mucosa. Many reports have stated that Panax ginseng and fermented red ginseng have anti-inflammatory effects, especially against Th2-type inflammation. This study was conducted to evaluate the therapeutic effects of fermented red ginseng in allergic rhinitis., Methods: In this 4-week, double-blind, placebo-controlled study, 59 patients with persistent perennial allergic rhinitis were randomly divided into two groups: those receiving fermented red ginseng tablets (experimental group) and those receiving placebo (control group). The primary efficacy variable was the total nasal symptom score (TNSS; rhinorrhea, sneezing, itchy nose, and nasal congestion). Secondary efficacy variables were the Rhinitis Quality of Life (RQoL) score and skin reactivity to inhalant allergens, as determined by the skin prick test., Results: There was no significant difference in the TNSS score and TNSS duration score between the experimental and placebo groups in weeks 1, 2, 3, or 4. For nasal congestion, fermented red ginseng was significantly effective (P<0.005), while placebo caused no change. The activity and emotion of RQoL improved markedly secondary to treatment with fermented red ginseng (P<0.05), while placebo caused no change. Additionally, fermented red ginseng reduced skin reactivity to sensitized perennial allergens (P<0.05). Fermented red ginseng was well tolerated., Conclusions: Fermented red ginseng improved nasal congestion symptoms and RQoL in patients with perennial allergic rhinitis.

Purpose: Asthma-related morbidity and mortality are increasing, and the financial burden imposed by this condition will substantially increase. Nevertheless, little information is available regarding the nature and magnitude of the burden due to asthma at the national level. This study was conducted to characterize the financial burden imposed by asthma in the Republic of Korea at the national level., Methods: The overall prevalence of asthma and the costs of related medical services were determined using data from the National Health Insurance Corporation, which is responsible for the National Health Insurance scheme. Indirect costs, including expenditures on complementary and alternative medicines, and the economic impact of an impaired quality of life (intangible costs) were estimated by surveying 660 asthmatics, and these estimates were transformed to the national level using the prevalence of asthma., Results: The prevalence of asthma and total costs related to the disease in 2004 were 4.19% and $2.04 billion, respectively. Direct costs and indirect costs contributed equally to total costs (46.9% and 53.1%, respectively). However, when intangible costs were included, total costs rose to $4.11 billion, which was equivalent to 0.44% of the national gross domestic product in 2004., Conclusions: The results provide evidence that asthma is a major health cost factor in the Republic of Korea and that intangible costs associated with asthma are significant cost drivers.

Purpose: Patient care based on asthma guidelines is cost-effective and leads to improved treatment outcomes. However, ineffective implementation strategies interfere with the use of these recommendations in clinical practice. This study investigated physicians' preferences for asthma guidelines, including content, supporting evidence, learning strategies, format, and placement in the clinical workplace., Methods: We obtained information through a questionnaire survey. The questionnaire was distributed to physicians attending continuing medical education courses and sent to other physicians by airmail, e-mail, and facsimile., Results: A total of 183 physicians responded (male to female ratio, 2.3:1; mean age, 40.4±9.9 years); 89.9% of respondents were internists or pediatricians, and 51.7% were primary care physicians. Physicians preferred information that described asthma medications, classified the disease according to severity and level of control, and provided methods of evaluation/treatment/monitoring and management of acute exacerbation. The most effective strategies for encouraging the use of the guidelines were through continuing medical education and discussions with colleagues. Physicians required supporting evidence in the form of randomized controlled trials and expert consensus. They preferred that the guidelines be presented as algorithms or flow charts/flow diagrams on plastic sheets, pocket cards, or in electronic medical records., Conclusions: This study identified the items of the asthma guidelines preferred by physicians in Korea. Asthma guidelines with physicians' preferences would encourage their implementation in clinical practice.