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Significant changes in CpG methylation have been identified in nasal polyps, which are the main targets of nonsteroidal anti-inflammatory drug-exacerbated respiratory disease (NERD); however, these polyps are composed of various cellular components. In the present study, whole-genome CpG methylation in peripheral blood lymphocytes (PBLs) was analyzed to define the epigenetic changes in lymphocytes, which are the primary immune cells involved in NERD.Genomic DNA from peripheral blood mononuclear cells from 27 NERD and 24 aspirin-tolerant asthma (ATA) was subjected to bisulfate conversion and a methylation array. Quantitative CpG methylation, the β-values as a quantitative measure of DNA methylation, in lymphocytes were calculated after adjustments for cellular composition.Fifty-six hypermethylated and three hypomethylated differentially methylated CpGs (DMCs) in PBLs in the NERD compared with ATA. The top 10 CpG loci predicted the methylation risk score, with a positive predictive value of 91.3%, a negative predictive value of 81.5% and an accuracy of 84.3%. As demonstrated in the nasal polyps, 30 DMCs were predicted to bind to the following 10 transcription factors, ranked in descending order: AP-2alphaA, TFII-1, STAT4, FOXP3, GR, c-Est-1, E2F-1, XBP1, ENKTF-1 and NF-1. Gene ontology analysis identified 13 categories such as regulation of T-helper 17 cell differentiation, including SMAD7 and NFKBIZ. PBLs in NERD contained no DMCs in genes associated with the prostaglandin and leukotriene pathways, which were found in ATA.PBLs in NERD form a unique pattern of DNA CpG methylation, and the combined analysis may provide predictive values for NERD.

Introduction: Allergic rhinitis and asthma share a common inflammatory mechanism and are closely related, recognized as “one airway disease.” Thus, the guidelines recommend allergic rhinitis and asthma be treated together, and leukotriene antagonists and antihistamines have been administered simultaneously; however, there are few reports of the use of combination drugs so far. Methods: The aim of the study was to evaluate the treatment effects and adverse events of Monterizine® (a combination of montelukast and levocetirizine); a total of 2,254 patients with perennial allergic rhinitis and asthma were prospectively enrolled from 60 hospitals nationwide in Korea. They were followed up for 3 (Period 1) or 6 months (Period 2). Total nasal symptom score (TNSS), satisfaction, and safety data were collected and compared to baseline. Results: TNSS scores were analyzed for 2,254 subjects. At Period 1 (n = 2,024) and 2 (n = 1,861), the scores decreased significantly from baseline (−1.20 ± 2.49 and −1.63 ± 2.78, p < 0.001). The mean quality of life (QoL) was significantly improved at Period 1 and 2 relative to baseline (−3.75 ± 6.58, −4.83 ± 7.11, both p < 0.0001). There were no serious adverse drug reactions, but there were some minor reactions including nasopharyngitis (2.92%), rhinitis (0.37%), and somnolence (0.34%). Conclusions: TNSS score and QoL were significantly improved by 3–6 months’ treatment with Monterizine without significant adverse reactions. These results indicate that Monterizine, as a combination drug, is effective and safe for improving nasal symptoms and quality of life in patients with allergic rhinitis who also have asthma.

For the past three decades, more than a thousand of genetic studies have been performed to find out the genetic variants responsible for the risk of asthma. Until now, all of the discovered single nucleotide polymorphisms have explained genetic effects less than initially expected. Thus, clarification of environmental factors has been brought up to overcome the 'missing' heritability. The most exciting solution is epigenesis because it intervenes at the junction between the genome and the environment. Epigenesis is an alteration of genetic expression without changes of DNA sequence caused by environmental factors such as nutrients, allergens, cigarette smoke, air pollutants, use of drugs and infectious agents during pre- and post-natal periods and even in adulthood. Three major forms of epigenesis are composed of DNA methylation, histone modifications, and specific microRNA. Recently, several studies have been published on epigenesis in asthma and allergy as a powerful tool for research of genetic heritability in asthma albeit epigenetic changes are at the starting point to obtain the data on specific phenotypes of asthma. In this presentation, we mainly review the potential role of DNA CpG methylation in the risk of asthma and its sub-phenotypes including nonsteroidal anti-inflammatory exacerbated respiratory diseases.

Background Asthma exacerbation threatens patient's life. Several genetic studies have been conducted to determine the risk factors for asthma exacerbation, but this information is still lacking. We aimed to determine whether genetic variants of Oxidative Stress Responsive Kinase 1 (OXSR1), a gene with functions of salt transport, immune response, and oxidative stress, are associated with exacerbation of asthma. Methods Clinical data were obtained from 1454 asthmatics and single nucleotide polymorphisms (SNPs) of OXSR1 were genotyped. Genetic associations with annual exacerbation rate were analyzed depending on smoking status. Results Eleven SNPs were selected using Asian data in the International HapMap database. The common allele of rs1384006 C > T of OXSR1 showed a significantly higher annual exacerbation rate than the rare allele in non-smoking asthmatics (CC vs. CT vs. TT: 0.43 ± 0.04 vs. 0.28 ± 0.03 vs. 0.31 ± 0.09, P = 0.004, Pcorr = 0.039). The frequent exacerbators had a significantly higher frequency of the common allele of rs1384006 C > T than did the infrequent exacerbators (74.4% vs. 55.2%, P = 0.004, Pcorr = 0.038). Conclusion The common allele of rs1384006 C > T of OXSR1 was associated with the asthma exacerbation rate and a higher risk of being a frequent exacerbator, indicating that non-smoking asthmatics who carry common alleles may be vulnerable to asthma exacerbations.

Background This pilot study aimed to investigate the current status of e-cigarettes (ECs) use patterns among patients with chronic airway disease or chronic respiratory symptoms and the effects of ECs use on respiratory and mental health. Methods A cross-sectional survey was conducted at the outpatient clinic of eight teaching hospitals in South Korea between November 2019 and December 2019. All adult ECs users (19 years and above) who visited the outpatient clinic as a patient with chronic airway disease or chronic respiratory symptoms were eligible to participate in this study. Results A total of 51 subjects responded to the survey. Most of the participants were male (92.2%) and the mean age was 41.8 years. Dominant airway diseases were asthma and chronic obstructive pulmonary disease. Most of the subjects had a history of cigarette smoking and 19 subjects were dual users of current cigarettes and ECs. Most of the subjects started ECs use due to health-related reasons. When comparing exclusive ECs users and dual users, St. George's respiraory questionaire (SGRQ) scores, the proportion of cases with moderate to severe depressive symptoms, and average Fagerstrom Test for Nicotine Dependence scores for ECs were higher in dual users than exclusive ECs users (mean 4.64 vs. 2.38, p=0.006), respectively. Conclusion Most of the subjects started ECs use due to health concerns, but dual users have more respiratory symptoms and higher nicotine dependence in this pilot study. One hypothesis that comes from these results is that greater nicotine dependence may influence behaviours, habits and views about ECs. These preliminary observations need confirmation in a large cohort.

Quinoline-3-carboxamides have been used to treat autoimmune/inflammatory diseases in humans because they inhibit the functions of S100 calcium-binding protein A9 (S100A9), which participates in the development of neutrophilic inflammation in asthmatics and in an animal model of neutrophilic asthma. However, the therapeutic effects of these chemicals have not been evaluated in asthma. The purpose of this study was to evaluate the effect of paquinimod, one of the quinoline-3-carboxamides, on a murine model of neutrophilic asthma.Paquinimod was orally administered to 6-week-old C57BL/6 mice sensitized and challenged with ovalbumin (OVA)/complete Freund's adjuvant (CFA) and OVA. Lung inflammation and remodeling were evaluated using bronchoalveolar lavage (BAL) and histologic findings including goblet cell count. S100A9, caspase-1, IL-1Paquinimod restored the enhancement of airway resistance and the increases in numbers of neutrophils and macrophages of BAL fluids and those of goblet cells in OVA/CFA mice toward the levels of sham-treated mice in a dose-dependent manner (0.1, 1, 10, and 25 mg/kg/day, p.o.). Concomitantly, p20 activated caspase-1, IL-1These data indicate that paquinimod effectively inhibits neutrophilic inflammation and remodeling in the murine model of neutrophilic asthma, possibly via downregulation of IL-17, IFN

Asthma exacerbation is induced by the interaction of genes and environmental factors such as cigarette smoke. NLRP4 counteracts the activity of the inflammasome, which is responsible for asthma exacerbation. In this study, we analyzed the association of single-nucleotide polymorphisms of NLRP4 with the annual rate of exacerbation and evaluated the additive effect of smoking in 1454 asthmatics. Asthmatics possessing the minor allele of rs1696718G A had more frequent exacerbation episodes than those homozygous for the common allele (0.59 vs. 0.36/year) and the association was present only in current and ex-smokers. There was a significant interaction between the amount smoked and rs16986718 genotypes (p = 0.014) and a positive correlation between the number of annual exacerbation episodes and amount smoked only in rs16986718G A AA homozygotes. The prevalence of frequent exacerbators (≥2 exacerbation episodes/year) was 2.5 times higher in rs16986718G A minor allele homozygotes than in common allele homozygotes (12.0% vs. 5.9%). Furthermore, the prevalence was 6 times higher in rs16986718G A minor allele homozygotes who were current and ex-smokers than in nonsmokers (25.6% vs. 4.1%). The minor allele of rs16986718G A in NLRP4 may be a genetic marker that predicts asthma exacerbation in adult asthmatics who smoke.

Exacerbation of asthma is affected by genetic and environmental factors, but little is known about genetic differences according to smoking status. We evaluated genetic factors associated with asthma exacerbations in smokers and non-smokers, and identified the underlying mechanisms via a genome-wide association study (GWAS) and gene-level analyses according to smoking status.A GWAS on the annual frequency of asthma exacerbations was performed in 420 non-smoking and 188 smoking patients with asthma. Gene-wise associations were analyzed by Multi-marker Analysis of GenoMic Annotation (MAGMA); Gene Ontology analysis was also performed.In the non-smoker group, 189 genes showed significant associations with the annual frequency of exacerbations (permutated P 0.001). The top 10 genes were F5, KLRC1, TAFA2, AIRE, IER3IP1, CHMP2A, IL31RA, ZNF497, DNMT3L, and MYT1L (permutated P = 1.0 × 10Our findings not only suggest novel genetic candidates for predicting asthma exacerbations, but also that asthma treatment strategies should take into account smoking behavior.

Background/aims The methacholine bronchial provocation test (MBPT) is used to detect and quantify airway hyper-responsiveness (AHR). Since improvements in the severity of asthma are associated with improvements in AHR, clinical studies of asthma therapies routinely use the change of airway responsiveness as an objective outcome. The aim of this study was to assess the relationship between serial MBPT and clinical profiles in patients with asthma. Methods A total of 323 asthma patients were included in this study. The MBPT was performed on all patients beginning at their initial diagnosis until asthma was considered controlled based on the Global Initiative for Asthma guidelines. A responder was defined by a decrease in AHR while all other patients were considered non-responders. Results A total of 213 patients (66%) were responders, while 110 patients (34%) were non-responders. The responder group had a lower initial PC20 (provocative concentration of methacholine required to decrease the forced expiratory volume in 1 second by 20%) and longer duration compared to the non-responder group. Members of the responder group also had superior qualities of life, compared to members of the non-responder group. Whole blood cell counts were not related to differences in PC20; however, eosinophil concentration was. No differences in sex, age, body mass index, smoking history, serum immunoglobulin E, or frequency of acute exacerbation were observed between responders and non-responders. Conclusions The initial PC20, the duration of asthma, eosinophil concentrations, and quality-of-life may be useful variables to identify improvements in AHR in asthma patients.

Background We previously reported that the ILVBL gene on chromosome 19p13.1 was associated with the risk for aspirin-exacerbated respiratory disease (AERD) and the percent decline of forced expired volume in one second (FEV1) after an oral aspirin challenge test. In this study, we confirmed the association between polymorphisms and haplotypes of the ILVBL gene and the risk for AERD and its phenotype. Methods We recruited 141 AERD and 995 aspirin-tolerant asthmatic (ATA) subjects. All study subjects underwent an oral aspirin challenge (OAC). Nine single nucleotide polymorphisms (SNPs) with minor allele frequencies above 0.05, which were present in the region from 2 kb upstream to 0.5 kb downstream of ILVBL in Asian populations, were selected and genotyped. Results In an allelic association analysis, seven of nine SNPs were significantly associated with the risk for AERD after correction for multiple comparisons. In a codominant model, the five SNPs making up block2 (rs2240299, rs7507755, rs1468198, rs2074261, and rs13301) showed significant associations with the risk for AERD (corrected P = 0.001–0.004, OR = 0.59–0.64). Rs1468198 was also significantly associated with the percent decline in FEV1 in OAC tests after correction for multiple comparisons in the codominant model (corrected P = 0.033), but the other four SNPs in hapblock2 were not. Conclusion To the best of our knowledge, this is the first report of an association between SNPs on ILVBL and AERD. SNPs on ILVBL could be promising genetic markers of this condition. Electronic supplementary material The online version of this article (10.1186/s12890-017-0556-6) contains supplementary material, which is available to authorized users.

S100A9 is an endogenous danger signal that promotes and exacerbates the neutrophilic inflammatory response. To investigate the role of S100A9 in neutrophilic asthma, S100A9 levels were measured in sputum from 101 steroid-naïve asthmatics using an ELISA kit and the levels were significantly correlated with percentages of neutrophils in sputum. Intranasal administration of recombinant S100A9 markedly increased neutrophil numbers at 8h and 24h later with concomitant elevation of IL-1β, IL-17, and IFN-γ levels. Treatment with an anti-S100A9 antibody restored the increased numbers of neutrophils and the increased airway resistance in OVA/CFA mice toward the levels of sham-treated mice. Concomitantly, the S100A9 and neutrophil elastase double positive cells were markedly reduced with attenuation of IL-1β, IL-17, and IFN-γ levels by the treatment with the anti-S100A9 antibody. Our data support a role of S100A9 to initiate and amplify the neutrophilic inflammation in asthma, possibly via inducing IL-1β, IL-17 and IFN-γ.

Background Interleukin-32(IL-32)γ is a pro-inflammatory cytokine involved in the development and severity of chronic inflammatory diseases, but its role in asthma is unclear. Objective This study was conducted to evaluate the relationship of IL-32γ levels in sputum with the severity of asthma. Methods IL-32γ levels in the supernatant of induced sputum obtained from 89 patients with stable asthma were measured using a sandwich enzyme-linked immunosorbent assay (ELISA). The relationships between sputum IL-32γ levels and baseline forced expiratory volume in 1 s (FEV 1 % pred.), inflammatory cell profiles in sputum, and annual frequency of asthma exacerbation were determined. Results IL-32γ was detected in the sputum of 25 of 89 (28.1%) asthma patients, and the levels of sputum were negatively correlated with FEV 1 % pred. (ρ = −0.312, p = 0.003). The annual exacerbation rate was significantly higher in this group than in the IL-32-negative group (n = 64) (p = 0.03). Sputum IL-32γ levels correlated well with the annual exacerbation rate (ρ = 0.261, p = 0.014), but there were no differences in the inflammatory cell profiles in the induced sputum of IL-32-positive and IL-32-negative patients. Conclusion The level of IL-32γ in induced sputum may be associated with asthma severity and related with higher risk of asthma exacerbation.

Background Aspirin-exacerbated respiratory diseases (AERD) are caused by ingestion of non-steroidal anti-inflammatory drugs and are characterized by acute bronchospasms and marked infiltration of eosinophils, the latter being attributable to altered synthesis of cysteinyl leukotrienes (LT) and prostaglandins (PG). Recently, the innate Th2 response is revealed to induce eosinophil infiltration in allergic inflammation, however the role of the innate Th2 response has not been studies in AERD. Thus, we evaluated the relationship between the innate Th2 cytokines including IL-25, thymic stromal lymphopoietin (TSLP) and IL-33 and the development of AERD. Methods and materials Plasma IL-25, IL-33, and TSLP levels were measured before and after aspirin challenge in subjects with AERD (n = 25) and aspirin-tolerant asthma (ATA, n = 25) by enzyme-linked immunosorbent assay (ELISA). Pre and post-aspirin challenge levels of LTC4 and PGD2 were measured using ELISA. Results Basal plasma IL-25 levels were significantly higher in AERD group than in normal controls and in ATA group (p = 0.025 and 0.031, respectively). IL-33 and TSLP levels were comparable in the AERD and ATA groups. After the aspirin challenge, the IL-25 levels were markedly decreased in the ATA group (p = 0.024), while not changed in the AERD group. The post-challenge IL-25 levels of all asthmatic subjects were significantly correlated with aspirin challenge - induced declines in FEV1 (r = 0.357, p = 0.011), but not with basal and post challenge LTC4 and PGD2 levels. Conclusions IL-25 is associated with bronchospasm after aspirin challenge, possibly via mechanisms other than altered LTC4 and PGD2 production.

BACKGROUND Aspirin-exacerbated respiratory disease (AERD) is characterized by a severe and sudden asthma attack after aspirin ingestion in patients with asthma. We studied associations with six common single nucleotide polymorphisms (SNP) of the gasdermin B gene (GSDMB). OBJECTIVE DNA obtained from 572 patients with asthma (with AERD, n = 165; and with aspirin-tolerant asthma, n = 407) and 391 normal controls was subjected to genotyping of six SNPs of GSDMB. METHODS An association analysis between GSDMB variants and AERD, with a fall rate of the forced expiratory volume in the first second of expiration (FEV1), was performed by using logistic and regression models. RESULTS Two SNPs in the intron (rs870830, rs7216389) showed significant associations with AERD (minimum p = 7.00 × 10-4 in the dominant model), even after Bonferroni correction (pcorr = 0.01 for the rs870830). Regression analysis of the genetic variants with FEV1 revealed significant associations with rs870830 and the haplotype 2 (pcorr = 4.71 × 10-4 for rs870830 and pcorr = 1.14 × 10-3 for haplotype 2, respectively). CONCLUSION We found strong associations among GSDMB polymorphisms and the presence of AERD and FEV1 in Korean patients with asthma. Our findings indicated that genetic variations of GSDMB may be associated with the development of AERD and aspirin-induced bronchospasm.

Neutrophilic airway inflammation represents a pathologically distinct form of asthma and frequently appears in symptomatic adulthood asthmatics. However, clinical impacts and mechanisms of the neutrophilic inflammation have not been thoroughly evaluated up to date. Areas covered: Currently, distinct clinical manifestations, triggers, and molecular mechanisms of the neutrophilic inflammation (namely Toll-like receptor, Th1, Th17, inflammasome) are under investigation in asthma. Furthermore, possible role of the neutrophilic inflammation is being investigated in respect to the airway remodeling. We searched the related literatures published during the past 10 years on the website of Pub Med under the title of asthma and neutrophilic inflammation in human. Expert commentary: Epidemiologic and experimental studies have revealed that the neutrophilic airway inflammation is induced by a wide variety of stimuli including ozone, particulate matters, cigarette smoke, occupational irritants, endotoxins, microbial infection and colonization, and aeroallergens. These triggers provoke diverse immune and inflammatory responses leading to progressive and sometimes irreversible airway obstruction. Clinically, neutrophilic airway inflammation is frequently associated with severe asthma and poor response to glucocorticoid therapy, indicating the need for other treatment strategies. Accordingly, therapeutics will be targeted against the main mediators behind the underlying molecular mechanisms of the neutrophilic inflammation.

PURPOSE Different characteristics of airway microbiome in asthmatics may lead to differential immune responses, which in turn cause eosinophilic or neutrophilic airway inflammation. However, the relationships among these factors have yet to be fully elucidated. METHODS Microbes in induced sputum samples were subjected to sequence analysis of 16S rRNA. Airway inflammatory phenotypes were defined as neutrophils (>60%) and eosinophils (>3%), and inflammation endotypes were defined by levels of T helper (Th) 1 (interferon-γ), Th2 (interleukin [IL]-5 and IL-13), Th-17 (IL-17), and innate Th2 (IL-25, IL-33, and thymic stromal lymphopoietin) cytokines, inflammasomes (IL-1β), epithelial activation markers (granulocyte-macrophage colony-stimulating factor and IL-8), and Inflammation (IL-6 and tumor necrosis factor-α) cytokines in sputum supernatants was assessed by enzyme-linked immunosorbent assay. RESULTS The numbers of operational taxonomic units were significantly higher in the mixed (n = 21) and neutrophilic (n = 23) inflammation groups than in the paucigranulocytic inflammation group (n = 19; p < 0.05). At the species level, Granulicatella adiacens, Streptococcus parasanguinis, Streptococcus pneumoniae, Veillonella rogosae, Haemophilus parainfluenzae, and Neisseria perflava levels were significantly higher in the eosinophilic inflammation group (n = 20), whereas JYGU_s levels were significantly higher in the neutrophilic inflammation group compared to the other subtypes (p < 0.05). Additionally, IL-5 and IL-13 concentrations were correlated with the percentage of eosinophils (p < 0.05) and IL-13 levels were positively correlated with the read counts of Porphyromonas pasteri and V. rogosae (p < 0.05). IL-1β concentrations were correlated with the percentage of neutrophils (p < 0.05). had a tendency to be positively correlated with the read count of JYGU_s (p = 0.095), and was negatively correlated with that of S. pneumoniae (p < 0.05). CONCLUSIONS Difference of microbial patterns in airways may induce distinctive endotypes of asthma, which is responsible for the neutrophilic or eosinophilic inflammation in asthma.

Background: Few studies have evaluated the impact of air pollution levels on the severity of exacerbations. Thus, we compared the relative risks posed by air pollutant levels on moderate and severe...

Stratification of asthmatic patients based on relevant biomarkers enables the prediction of responsiveness against immune-targeted therapies in patients with asthma. Individualised therapy in patients with eosinophilic asthma has yielded improved clinical outcomes; similar approaches in patients with neutrophilic asthma have yet to be developed. We determined whether colony-stimulating factors (CSFs) in the airway reflect the inflammatory phenotypes of asthma and contribute to disease progression of neutrophilic asthma.We analysed three different mouse models of asthma and assessed cytokine profiles in sputum from human patients with asthma stratified according to inflammatory phenotype. In addition, we evaluated the therapeutic efficacy of various cytokine blockades in a mouse model of neutrophilic asthma.Among the CSFs, airway granulocyte CSF (G-CSF) contributes to airway neutrophilia by promoting neutrophil development in bone marrow and thereby distinguishes neutrophilic inflammation from eosinophilic inflammation in mouse models of asthma. G-CSF is produced by concurrent stimulation of the lung epithelium with interleukin (IL)-17A and tumour necrosis factor (TNF)-α; therefore, dual blockade of upstream stimuli using monoclonal antibodies or genetic deficiency of the cytokines in IL-17A×TNF-α double-knockout mice reduced the serum level of G-CSF, leading to alleviation of neutrophilic inflammation in the airway. In humans, the sputum level of G-CSF can be used to stratify patients with asthma with neutrophil-dominated inflammation.Our results indicated that myelopoiesis-promoting G-CSF and cytokines as the upstream inducing factors are potential diagnostic and therapeutic targets in patients with neutrophilic asthma.

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.

Grilling, a common cooking method worldwide, can produce more toxic gases than other cooking methods. However, the impact of frequently grilling meat or fish at home on airflow limitation in adult asthma has not been well elucidated. We performed a prospective cohort study of 91 adult patients with asthma enrolled from 2 university hospitals. Of the patients, 39 (42.9%) grilled meat or fish at least once a week and 52 (57.1%) less than once a week. Patients who grilled at least once a week tended to have lower peak expiratory flow rate (PEFR) than those who grilled less than once a week (median, 345.5 L/min; 95% confidence interval [CI], 291.8–423.2 L/min vs. median, 375.1 L/min; 95% CI, 319.7–485.7 L/min; P = 0.059). Among patients with severe asthma who received step 4-5 treatment, PEFR was significantly lower in patients who grilled at least once a week compared with those who grilled less than once a week (median, 297.8 L/min; 95% CI, 211.3–357.7 L/min vs. median, 396.1 L/min; 95% CI, 355.0–489.6 L/min; P < 0.001). Our results suggest that the frequency of grilling meat or fish at home may affect PEFR in asthmatic patients, especially those with severe asthma who needed a high level of asthma treatment.

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.

Purpose Asthma is a heterogeneous disease that responds to medications to varying degrees. Cluster analyses have identified several phenotypes and variables related to fixed airway obstruction; however, few longitudinal studies of lung function have been performed on adult asthmatics. We investigated clinical, demographic, and inflammatory factors related to persistent airflow limitation based on lung function trajectories over 1 year. Methods Serial post-bronchodilator forced expiratory volume (FEV) 1% values were obtained from 1,679 asthmatics who were followed up every 3 months for 1 year. First, a hierarchical cluster analysis was performed using Ward's method to generate a dendrogram for the optimum number of clusters using the complete post-FEV1 sets from 448 subjects. Then, a trajectory cluster analysis of serial post-FEV1 sets was performed using the k-means clustering for the longitudinal data trajectory method. Next, trajectory clustering for the serial post-FEV1 sets of a total of 1,679 asthmatics was performed after imputation of missing post-FEV1 values using regression methods. Results Trajectories 1 and 2 were associated with normal lung function during the study period, and trajectory 3 was associated with a reversal to normal of the moderately decreased baseline FEV1 within 3 months. Trajectories 4 and 5 were associated with severe asthma with a marked reduction in baseline FEV1. However, the FEV1 associated with trajectory 4 was increased at 3 months, whereas the FEV1 associated with trajectory 5 was persistently disturbed over 1 year. Compared with trajectory 4, trajectory 5 was associated with older asthmatics with less atopy, a lower immunoglobulin E (IgE) level, sputum neutrophilia and higher dosages of oral steroids. In contrast, trajectory 4 was associated with higher sputum and blood eosinophil counts and more frequent exacerbations. Conclusions Trajectory clustering analysis of FEV1 identified 5 distinct types, representing well-preserved to severely decreased FEV1. Persistent airflow obstruction may be related to non-atopy, a low IgE level, and older age accompanied by neutrophilic inflammation and low baseline FEV1 levels.

Background Annexin-A1 (ANXA1) is a glucocorticoid-induced protein with multiple actions in the regulation of inflammatory cell activation. The anti-inflammatory protein ANXA1 and its N-formyl peptide receptor 2 (FPR2) have protective effects on organ fibrosis. However, the exact role of ANXA1 in asthma remains to be determined. The aim of this study was to identify the role of ANXA1 in bronchial asthma. Methods In mice sensitized and challenged with ovalbumin (OVA-OVA mice) and mice sensitized with saline and challenged with air (control mice), we investigated the potential links between ANXA1 levels and bronchial asthma using ELISA, immunoblotting, and immunohistochemical staining. Moreover, we also determined ANXA1 levels in blood from 50 asthmatic patients (stable and exacerbated states). Results ANXA1 protein levels in lung tissue and bronchoalveolar lavage fluid were significantly higher in OVA-OVA mice compared with control mice. FPR2 protein levels in lung tissue were significantly higher in OVA-OVA mice compared with control mice. Plasma ANXA1 levels were increased in asthmatic patients compared with healthy controls. Plasma ANXA1 levels were significantly lower in exacerbated patients compared with stable patients with bronchial asthma (p

Purpose Asthma is a heterogeneous disease characterized by various types of airway inflammation and obstruction. Therefore, it is classified into several subphenotypes, such as early-onset atopic, obese non-eosinophilic, benign, and eosinophilic asthma, using cluster analysis. A number of asthmatics frequently experience exacerbation over a long-term follow-up period, but the exacerbation-prone subphenotype has rarely been evaluated by cluster analysis. This prompted us to identify clusters reflecting asthma exacerbation. Methods A uniform cluster analysis method was applied to 259 adult asthmatics who were regularly followed-up for over 1 year using 12 variables, selected on the basis of their contribution to asthma phenotypes. After clustering, clinical profiles and exacerbation rates during follow-up were compared among the clusters. Results Four subphenotypes were identified: cluster 1 was comprised of patients with early-onset atopic asthma with preserved lung function, cluster 2 late-onset non-atopic asthma with impaired lung function, cluster 3 early-onset atopic asthma with severely impaired lung function, and cluster 4 late-onset non-atopic asthma with well-preserved lung function. The patients in clusters 2 and 3 were identified as exacerbation-prone asthmatics, showing a higher risk of asthma exacerbation. Conclusions Two different phenotypes of exacerbation-prone asthma were identified among Korean asthmatics using cluster analysis; both were characterized by impaired lung function, but the age at asthma onset and atopic status were different between the two.

Previously, we used a proteomic approach to demonstrate that the protein level of fatty acid-binding protein 1 (FABP1) is increased in nasal polyps in patients with aspirin-exacerbated respiratory disease (AERD). To reveal the genetic effect of FABP1 variants, we evaluated the association of FABP1 polymorphisms with the risk of AERD in 207 asthmatics with AERD and 1019 aspirin-tolerant asthmatics (ATA). Seven polymorphisms of FABP1 were selected from the National Center for Biotechnology Information (build 36) using minor allele frequency and linkage disequilibrium criteria. The genotype and haplotype distributions were not significantly different between the AERD and ATA groups in all of the genetic models. The percent decline of forced expiratory volume in 1 second (FEV1) after the oral aspirin challenge (OAC) test did not differ according to single-nucleotide polymorphism (SNP) genotypes. In haplotype analysis, asthmatic patients who were BL2ht2 homozygotes showed a greater decline in FEV1 after the OAC test than subjects who possessed 1 or no copy of BL2ht2 (P = 0.035). However, these observations were not significant after correction for multiple comparisons (corrected P value = 1.00). Neither genotype nor haplotype was associated with the presence of nasal polyposis in the study subjects. Although we did not find a significant association between the FABP1 polymorphisms and AERD, our data suggest that the 7 SNPs are not associated with the increased expression of FABP1 in asthmatic patients with AERD. Further studies of epigenetic factors that may contribute to the increased expression of FABP1 in AERD should be performed.

Objectives Asthma can be suppressed by inhaled corticosteroids (ICS). However, response to ICS shows marked inter-individual variability. This study is aimed to identify the genetic variants associated with the change in the percentage of forced expiratory volume in 1 second (%ΔFEV1) following ICS treatment. Methods A genome-wide association study was performed in a Korean asthmatic cohort. To further investigate these genetic associations, 11 additional single-nucleotide polymorphisms (SNPs) on the allantoicase (ALLC) gene were selected from the HapMap database and genotyped in the same asthmatic patients in the follow-up study. Results In a genome-wide study, we identified the lowest P-value in ALLC, but none of the SNPs met the genome-wide association criteria (P Conclusions Although the associated signals could not overcome the genome-wide multiple correction due to small sample size (n = 189), our results suggest that associated SNPs of ALLC might be genetic predictors of response to ICS, at least with respect to ΔFEV1 in Korean asthmatics.

Aspirin-exacerbated respiratory disease (AERD) has attracted a great deal of attention because of its association with increased asthma severity. To identify plasma biomarkers for the prediction of AERD, the six most abundant plasma proteins (albumin, IgG, antitrypsin, IgA, transferrin, and haptoglobin) in pooled plasma samples were removed using a multiple affinity removal system column. Two-dimensional gel electrophoresis (2DE) was used for differential display proteomic analysis of the pooled plasma. Proteins were identified by matrix assisted laser desorption ionization time-of-flight (MALDI-TOF)/TOF. Enzyme-linked immunosorbent assay (ELISA) was performed to identify and quantify apolipoprotein H (Apo H) in plasma from subjects with AERD and aspirin-tolerant asthma (ATA). Eight protein spots showed differences in relative intensity between pooled plasma from subjects with AERD (n = 8) and those with ATA (n = 8). MALDI-TOF/TOF analysis showed decreases in the levels of alpha-fibrinogen precursor, Apo H, fibrin beta, and proapolipoprotein in AERD as compared with ATA, and increases in chain A human complement component C3, 90-kDa heat shock protein, complement component C4a, and kininogen-1 isoform 2. Apo H concentrations were significantly increased in plasma from subjects with ATA than those with AERD and normal controls, as measured by ELISA (P

Member RAS oncogene family (RAB1A), a member of the RAS oncogene family, cycles between inactive GDP-bound and active GTP-bound forms regulating vesicle transport in exocytosis. Thus, functional alterations of the RAB1A gene may contribute to aspirin intolerance in asthmatic sufferers. To investigate the relationship between single-nucleotide polymorphisms (SNPs) in the RAB1A gene and aspirin-exacerbated respiratory disease (AERD), asthmatics (n=1197) were categorized into AERD and aspirin-tolerant asthma (ATA). All subjects were diagnosed as asthma on the basis of the Global Initiative for Asthma (GINA) guidelines. AERD was defined as asthmatics showing 15% or greater decreases in forced expiratory volume in one second (FEV(1)) or naso-ocular reactions by the oral acetyl salicylic acid (ASA) challenge (OAC) test. In total, eight SNPs were genotyped. Logistic regression analysis identified that the minor allele frequency of +14444 TG and +41170 CG was significantly higher in the AERD group (n=181) than in the ATA group (n=1016) (p=0.0003-0.03). Linear regression analysis revealed a strong association between the SNPs and the aspirin-induced decrease in FEV(1) (p=0.0004-0.004). The RAB1A gene may play a role in the development of AERD in asthmatics and the genetic polymorphisms of the gene have the potential to be used as an indicator of this disease.

Nonsteroidal anti-inflammatory drug (NSAID)-exacerbated respiratory disease (NERD) has attracted a great deal of attention because of its association with severe asthma. However, it remains widely underdiagnosed in asthmatics as well as the general population. Upon pharmacological inhibition of cyclooxygenase 1 by NSAIDs, production of anti-inflammatory prostaglandin E2 and lipoxins ceases, while release of proinflammatory cysteinyl leukotrienes increases. To determine the underlying mechanisms, many studies have attempted to elucidate the genetic variants, such as single nucleotide polymorphisms, responsible for alterations of prostaglandins and leukotrienes, but the results of these genetic studies could not explain the whole genetic pathogenesis of NERD. Accordingly, the field of epigenetics has been introduced as an additional contributor to genomic alteration underlying the development of NERD. Recently, changes in CpG methylation, as one of the epigenetic components, have been identified in target tissues of NERD. This review discusses in silico analyses of both genetic and epigenetic components to gain a better understanding of their complementary roles in the development of NERD. Although the molecular mechanisms underlying NERD pathogenesis remain poorly understood, genetic and epigenetic variations play significant roles. Our results enhance the understanding of the genetic and epigenetic mechanisms involved in the development of NERD and suggest new approaches toward better diagnosis and management.

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.

For the past three decades, a large number of genetic studies have been performed to examine genetic variants associated with asthma and its subtypes in hopes of gaining better understanding of the mechanisms underlying disease pathology and to identify genetic biomarkers predictive of disease outcomes. Various methods have been used to achieve these objectives, including linkage analysis, candidate gene polymorphism analysis, and genome-wide association studies (GWAS); however, the degree to which genetic variants contribute to asthma pathogenesis has proven to be much less significant than originally expected. Subsequent application of GWAS to well-defined phenotypes, such as occupational asthma and non-steroidal anti-inflammatory drugexacerbated respiratory diseases, has overcome some of these limitations, although with only partial success. Recently, a combinatorial analysis of single nucleotide polymorphisms (SNPs) identified by GWAS has been used to develop sets of genetic markers able to more accurately stratify asthma subtypes. In this review, we discuss the implications of the identified SNPs in diagnosis of asthma and its subtypes and the progress being made in combinatorial analysis of genetic variants.

Aspirin-exacerbated respiratory disease (AERD) is characterized by the development of airway obstruction in asthmatic individuals following the ingestion of aspirin or other nonsteroidal anti-inflammatory drugs. TAPBP (TAP-binding protein, tapasin) is upregulated by eicosanoids, which act as potent inflammatory molecules in aspirin-related reactions. Thus, functional alterations in the TAPBP gene may contribute toward AERD.We examined the relationship between the single nucleotide polymorphisms on the TAPBP gene and AERD.A group of asthmatic patients (n=1252) underwent the oral aspirin challenge. Oral aspirin challenge reactions were categorized into two groups as follows: 15% or greater decreases in forced expiratory volume in 1 s or naso-ocular and skin reactions (AERD), or 15% or less decreases in forced expiratory volume in 1 s without naso-ocular and skin reactions (aspirin-tolerant asthma). Five single nucleotide polymorphisms of the TAPBP gene were genotyped.Logistic regression analysis showed that the minor allele frequencies of TAPBP rs2071888 CG (Thr260Arg) on exon 4 (P0.05), which was in absolute linkage disequilibrium with rs1059288 TC on 3'UTR, were significantly higher in the AERD group than in the aspirin-tolerant asthma group, and the P values remained significant after multiple comparisons (Pcorr=0.006, odds ratio: 1.37, 95% confidence interval: 1.11-1.69, additive model; Pcorr=0.009, odds ratio: 1.52, 95% confidence interval: 1.14-2.03, dominant model). Alpha-helical wheel plotting showed that 260Arg had greater hydrophilic helical property than 260Thr.TAPBP polymorphisms may play a role in the development of AERD.

Background In this study, the association of asthma with CD53, a member of the tetraspanin family, was assessed for the first time in a mechanism-based study. Methods Genetic polymorphisms of CD53 were analyzed in 591 subjects and confirmed in a replication study of 1001 subjects. CD53 mRNA and protein levels were measured in peripheral blood leukocytes, and the effects of the promoter polymorphisms on nuclear factor binding were examined by electrophoretic mobility shift assay. Cellular functional studies were conducted by siRNA transfections. Results Among tagging SNPs of CD53, the − 1560 C>T in the promoter region was significantly associated with asthma risk. Compared with the CC genotype, the CT and TT genotypes were associated with a higher asthma risk, with odd ratios of 1.74 ( P = 0.009) and 2.03 ( P = 0.004), respectively. These findings were confirmed in the replication study with odd ratios of 1.355 ( P = 0.047) and 1.495 ( P = 0.039), respectively. The − 1560 C>T promoter SNP had functional effects on nuclear protein binding as well as mRNA and protein expression levels in peripheral blood leukocytes. When CD53 was knocked down by siRNA in THP-1 human monocytic cells stimulated with house dust mite, the production of inflammatory cytokines as well as NFκB activity was significantly over-activated, suggesting that CD53 suppresses over-activation of inflammatory responses. Conclusions The − 1560 C>T SNP is a functional promoter polymorphism that is significantly associated with population asthma risk, and is thought to act by directly modulating nuclear protein binding, thereby altering the expression of CD53, a suppressor of inflammatory cytokine production.

Asthma is a global health problem which threatens approximately 300 million patients worldwide. Among them, up to 20 % of the asthma patients are classified as aspirin exacerbated respiratory disease (AERD). Interleukin-1 receptor associated kinase (IRAK2) is associated with necrosis factor kappa B (NF-кB) pathway via interleukin-1 (IL-1) signaling. NF-кB pathway is known to be involved in asthma development, and several interleukin and IRAK family members have also been reported to be associated with asthma or AERD. Since IRAK2 plays an important role in the asthma etiology, we hypothesized that the genetic variants of IRAK2 may be associated with AERD. This study genotyped a total of 25 common single nucleotide polymorphisms (SNPs) in 163 AERD cases and 429 aspirin-tolerant asthma (ATA) controls. As a result, no significant association was found between the genetic variants of IRAK2 and AERD (P > 0.05). In further regression analysis for the forced expiratory volume in 1 s (FEV1) decline, an important phenotype for diagnosing AERD, although one haplotype (BL1_ht3) showed a nominal association with FEV1 decline (P = 0.04), the significance disappeared after correction for multiple testing (P > 0.05). Despite limitations in our study and need for replications, our results suggest that the genetic variants of IRAK2 might not be associated with AERD and the obstructive symptoms in asthma.

The aim of the present study was to develop a diagnostic set of single-nucleotide polymorphisms (SNPs) for discriminating aspirin-exacerbated respiratory disease (AERD) from aspirin-tolerant asthma (ATA) using the genome-wide association study (GWAS) data; the GWAS data were filtered according to p-values and odds ratios (ORs) using PLINK software, and the 10 candidate SNPs most closely associated with AERD were selected, based on 100 AERD and 100 ATA subjects. Using multiple logistic regression and receiver-operating characteristic (ROC) curve analysis, eight SNPs were chosen as the best model for distinguishing between AERD and ATA. The relative risk for AERD in each subject was calculated based on the relative risk of each of the eight SNPs. Ten of the original 109,365 SNPs highly associated (filtered with p0.001 and ORs) with the risk for AERD were selected. A combination model of the eight SNPs among the 10 SNPs showed the highest area under the ROC curve of 0.9. The overall relative risk for AERD based on the eight SNPs was significantly different between the AERD and ATA groups (p=2.802E-21), and the sensitivity and specificity were 78% and 88%, respectively. The candidate set of eight SNPs may be useful in predicting the risk for AERD.

BACKGROUND: The functional role of the human diffuse panbronchiolitis critical region 1 (DPCR1) gene, located in the major histocompatibility complex class I, has not been widely investigated. However, this gene is a well known genetic marker for diffuse panbronchiolitis, a disease affecting human respiratory bronchioles. In this study we explored the association between polymorphisms in DPCR1 and aspirin-exacerbated respiratory disease (AERD), an asthma phenotype. METHODS: Genotyping of 6 polymorphisms was carried out in a total of 189 Korean asthmatic patients stratified into 93 AERD cases and 96 aspirin tolerant asthma controls. Subjects who exhibited significant decrease of FEV1 by aspirin provocation were identified as AERD subjects. Logistic and regression analyses were performed to investigate the association between DPCR1 polymorphisms and the risk of AERD as well as FEV1 decline. RESULTS: Initial analysis revealed significant association of rs2517449 with AERD, with a P value of .03 via a recessive model; however, the association signal disappeared after multiple testing corrections. In addition, rs2517449 and rs2240804 also showed association signals with decline of FEV1 after aspirin provocation (P = .007 and .03, respectively, in a recessive model). After testing for multiple comparisons, only the association signal from rs2517449 was retained (Pcorr = .04), while other polymorphisms showed no associations with the risk of AERD and FEV1 decline. CONCLUSIONS: Our results show that polymorphisms in DPCR1 are not associated with the risk of AERD.

Background and objective: One of the clinical manifestations of refractory asthma (RA) in a certain group of patients is persistent airway obstruction (PAO), despite treatment with high doses of inhaled and/or systemic corticosteroids. Airway neutrophilic inflammation is frequently observed in RA; however, the relationship between neutrophilic inflammation and PAO has not been evaluated in this group of patients. The aim of this study was to compare the clinical parameters and patterns of inflammatory cells between patients with or without PAO due to RA, and to identify the factors associated with PAO. Methods: Seventy-seven patients with RA were recruited from a cohort of 2298 asthmatic patients. Sputum differential cell counts were performed at initial presentation. Clinical and physiological parameters were compared between patients with (n = 19) or without PAO (n = 58). Results: The group with PAO had a longer duration of asthma and a higher frequency of near-fatal asthma than the non-PAO group, although higher doses of inhaled corticosteroids were used in the PAO group (P = 0.037). Neutrophilic inflammation was predominant in the group with PAO, whereas eosinophilic inflammation was predominant in the non-PAO group (P = 0.003). When both groups were stratified according to smoking status, the non-smoking PAO group had the longest duration of asthma, with early onset of asthma (P

Background Nasal polyps, part of the aspirin triad symptoms, are edematous protrusions arising from the mucosa of the nasal sinuses. Although the causative factors and pathogenesis of the polyps are unknown, the significant effect of human leukocyte antigen-DR (HLA-DR) expression in nasal polyps and genetic associations of the major histocompatibility complex class II, DR alpha (HLA-DRA) with immune-mediated diseases have been revealed. Methods To investigate the associations of HLA-DRA polymorphisms with nasal polyposis in asthmatic patients and in aspirin-hypersensitive subgroups, 22 single nucleotide polymorphisms (SNPs) were genotyped in a total of 467 asthmatic patients including 158 nasal polyp-positive and 309 polyp-negative subjects. Results Statistical analysis showed that four SNPs (p = 0.0005-0.02; Pcorr = 0.009-0.033) and one haplotype (p = 0.002; Pcorr = 0.029) were significantly associated with the presence of nasal polyposis in asthmatic patients. In further analysis, although significant signals disappeared after corrections for multiple testing, two HLA-DRA polymorphisms (rs9268644C>A, rs3129878A>C) were found to be potential markers for nasal polyp development in aspirin-tolerant asthma (p = 0.005 and 0.007, respectively) compared with the aspirin-exacerbated respiratory disease (p > 0.05) subgroup. In silico analysis predicted major “C” allele of rs14004C>A in 5’ -untranslated region as a potential binding site for regulatory glucocorticoid receptor. In addition, sequence nearby rs1051336G>A is suspected to be a pyrimidine-rich element that affects mRNA stability. Conclusion Despite the need for replication in larger cohorts and/or functional evaluations, our findings suggest that HLA-DRA polymorphisms might contribute to nasal polyposis susceptibility in patients with asthma

The angiotensinogen ( AGT ) gene enhances the effect of several bronchoconstrictors and produces a peptide that is accumulated in the airways of asthma patients; events that may underpin the pathogenesis of aspirin-intolerant asthma (AIA). To carry out a case-control analysis between AGT and aspirin-induced bronchospasm following treatment with an anti-asthma drug, montelukast (MLK), 38 single nucleotide polymorphisms (SNPs) in AGT were genotyped in 56 AIA cohort. Genotyping was performed with TaqMan assay and haplotypes were inferred using PHASE algorithm ver. 2.0. Statistical analyses of each SNPs and haplotypes were performed using SAS version 9.1. Among 13 variants displaying significant signals, two SNPs ( +2401C>G and +2476C>T ) in the intronic region of AGT were significantly associated with modification of drug response even after correction for multiple testing ( P = 0.0009–0.002; P corr = 0.02–0.03). Furthermore, the two variants also exhibited associations with MLK response rate ( P = 0.0003–0.0006; P corr = 0.006–0.01). Although our results are preliminary and further replication in a larger-scale group of subjects should be warranted, these observations provide evidence that AGT variants might be one of genetic factors involved in the response of anti-asthma drugs in AIA patients.

Aspirin exacerbated respiratory disease (AERD) is a clinical condition characterized by severe decline in forced expiratory volume in one second (FEV1) following the ingestion of non-steroidal anti-inflammatory drugs (NSAIDs), including aspirin. The exacerbated inflammatory response in Fancc-deficient mice has been reported to be associated with hemopoietic responses that are also related to AERD pathogenesis. To investigate associations of FANCC polymorphisms with AERD and related phenotypes, this study genotyped 25 common single nucleotide polymorphisms (SNPs) in a total of 592 Korean asthmatics including 163 AERD and 429 aspirin-tolerant asthma (ATA) subjects. Logistic analysis revealed that genetic polymorphisms of the FANCC gene might not be directly related to AERD development and nasal polyposis (P > 0.05). However, the FEV1 decline by aspirin provocation showed significant associations with FANCC polymorphisms (P = 0.006-0.04) and a haplotype (unique to rs4647416G > A, P = 0.01 under co-dominant, P = 0.006 under recessive model). In silico analysis showed that the "A" allele of rs4647376C > A, which was more prevalent in AERD than in ATA, could act as a potential branch point (BP) site for alternative splicing (BP score = 4.16). Although replications in independent cohorts and further functional evaluations are still needed, our preliminary findings suggest that FANCC polymorphisms might be associated with the obstructive symptoms in allergic diseases.

Background and objective: The neurotransmitter, 5-hydroxytryptamine, acts as an immunomodulator by stimulating the release of inflammatory cytokines and regulating the function of dendritic cells and monocytes. The 5-hydroxytryptamine receptor 4 (HTR4) gene is located in a region previously linked to an increased risk of asthma and atopy. The aim of this study was to investigate the association between HTR4 and asthma. Methods: Thirty-two single nucleotide polymorphisms (SNP) in HTR4 were investigated by direct sequencing of 24 DNA samples from unrelated Korean subjects. Results: The 32 genetic variants comprised 22 intronic SNP, two SNP in the 3′-untranslated region (exon 7) and eight SNP in the 3′-downstream region. Logistic regression analysis showed that two intronic polymorphisms were significantly associated with the risk of asthma. Two minor HTR4 alleles, +142828G > A and +122769G > A, occurred at significantly higher frequencies in the asthmatic group than in the healthy control group (49.59% vs 42.29%, P = 0.003, and 47.99% vs 40.35%, P = 0.008, respectively), and these differences remained significant after correction for multiple testing (P = 0.05, dominant mode of inheritance; and P = 0.03, dominant mode, respectively). Haplotype analysis revealed three haplotype blocks. The frequency of haplotype 1 in block 2 was significantly higher in asthmatics (P = 0.003, dominant mode), whereas the frequency of haplotype 4 in block 3 was significantly lower in asthmatics (P = 0.0009, dominant mode). Conclusions: SNP and haplotypes of the HTR4 gene were associated with the asthma phenotype and genetic variation of HTR4 may affect susceptibility to the development of asthma.

Aim: Thromboxane A synthase (TBXAS1) converts prostaglandin H to thromboxane A, a potent constrictor of smooth respiratory muscle. Thus, functional alterations of the TBXAS1 gene may contribute to aspirin-intolerant asthma (AIA). Materials & methods: We investigated the relationship between SNPs in the TBXAS1 gene and AIA. Asthmatics (n = 470) were categorized into AIA (20% or greater decreases in forced expiratory volume in 1 s [FEV1], or 15% to 19% decreases in FEV1 with naso-ocular or cutaneous reactions) and aspirin-tolerant asthma (ATA). A total of 101 SNPs were genotyped. mRNA expression of the TBXAS1 gene by peripheral blood mononuclear cells and plasma thromboxane B2 (TXB2) concentrations were measured by reverse transcriptase (RT)-PCR and ELISA. Results: Logistic regression analysis showed that the rare allele frequency of rs6962291 in intron 9 was significantly lower in the AIA group (n = 115) than in the ATA group (n = 270) (pcorr = 0.04). The linear regression analysis revealed a strong association of rs6962291 with the aspirin challenge-induced FEV1 fall (p = 0.003). RT-PCR revealed an exon-12-deleted splice variant. We measured TBXAS1 mRNA levels in peripheral blood mononuclear cells. The mRNA levels of the full-length wild-type and splice variant were significantly higher in the TT homozygotes than in the AA homozygotes of rs6962291 (1.00 ± 0.18 vs 0.57 ± 0.03 and 1.00 ± 0.18 vs 0.21 ± 0.05, p = 0.047 and 0.001, respectively). The plasma TXB2 level was significantly lower in rs6962291 AA carriers than in rs6962291 TT (p = 0.016) carriers. Conclusion: The rare allele of rs6962291 may play a protective role against aspirin hypersensitivity via a lower catalytic activity of the TBXAS1 gene, attributed to the increase of a nonfunctioning isoform of TBXAS1. Original submitted 26 August 2010; Revision submitted 29 October 2010.

Objective Aspirin affects interleukin-4 (IL-4) synthesis; however, the genetic role of IL-4 has not been evaluated in asthmatics with aspirin hypersensitivity. The objective of the study was to examine the influence of single nucleotide polymorphisms (SNPs) in IL-4 gene on aspirin hypersensitivity in asthmatics at the genetic and molecular levels. Methods Aspirin-intolerant (AIA, n= 103 ) and aspirin-tolerant asthmatics (n=2 70 ) were genotyped and functional promoter assays were performed. Results Of 15 S N Ps tested, seven (- 589T > C (rs2243250) in promoter, -33T>C (rs2070874) in the 5'-untranslated region, +4047A>G (rs2243266), + 4144C> G (rs2243267), + 4221C> A (rs2243268), +4367G>A (rs2243270), and +5090A>G (rs2243274) in introns) were significantly associated with AIA risk. The frequency of the rare allele (C) of -589T>C was higher in the AIA group than in the aspirin-tolerant asthmatic group (P corr =0.016), and a gene dose-dependent decline in forced expiratory volume in 1 s was noted after an aspirin challenge (P=0.0009). Aspirin unregulated IL-4 mRNA production in Jurkat T and K562 leukemia cells. A reporter plasmid assay revealed that aspirin augmented IL-4 promoter transactivation with the -589T>C C and -33T>C C alleles, compared with that bearing the -589T> C T and -33T > C T alleles. Further, electrophoretic mobility shift assay showed the formation of nuclear complexes with -33T>C and - 589T > C allele-containing probes; this was augmented by aspirin. The complexes formed with the -33T>C and -589T>C probes were shifted by treatment with anti-CCAAT-enhancer-binding proteins β and anti-nuclear factor of activated T-cells antibodies, respectively, indicating the inclusion of these transcription factors. Conclusion Aspirin may regulate IL4 expression in an allele-specific manner by altering the availability of transcription factors to the key regulatory elements in the IL4 promoter, leading to aspirin hypersensitivity.

Nuclear factor-κB (NF-κB) orchestrates the expression of genes responsible for airway inflammation and remodeling in asthma. The activity of NF-κB is tightly regulated by IKBA, which may be modulated by genetic polymorphisms of the IKBA gene. We investigated the association between asthma susceptibility and IKBA gene polymorphisms in a Korean population. Genotyping was performed in BA (bronchial asthma) and NC (normal control). We measured reverse transcription-polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay, and luciferase reporter assays, respectively. A -673A>T (rs2233407) was associated with asthma development in subjects with atopic asthma (odds ratio = 0.56, p = 0.004). The IKBA mRNA level was higher in B-cell lines with the rs2233407 TT genotype compared with those with the AA genotype (p = 0.024). The luciferase activity of the rs2233407 T genotype was higher than that of the A (p = 0.002). The cytoplasmic levels of total IKBA and IKBA [p-S32] were higher in B cell lines of the rs2233407 TT genotype than those of the AA (p = 0.016 and p = 0.036, respectively), whereas nuclear NF-κB activity in cells with the IKBA rs2233407 AA genotype was higher than in cells with the AA (p = 0.038). The IKBA rs2233407 A>T polymorphism may predispose individuals to the development of atopic asthma via regulation of IKBA gene expression at the transcriptional level.

Aspirin-intolerant asthma (AIA), as a clinical syndrome caused by aspirin, is characterized by lung inflammation and reversible bronchoconstriction. Recently, the altered trafficking and diminished airway reactivity have been implicated in allergic airway remodeling. The stromal membrane-associated protein 1-like (SMAP1L) exerts common and distinct functions in vesicle trafficking including endocytosis. The disturbance of pulmonary surfactant synthesis has been elucidated to be associated with asthma experimentally. Moreover, in alveolar type II (ATII) cells that synthesize pulmonary surfactant, alterations of clathrin-dependent endocytosis cause disturbance at the surfactant function, suggesting that SMAP1L, which directly interacts with clathrin, could be associated with asthma and related phenotypes.To verify our hypothesis that SMAP1L could play a role in the development of AIA, this study investigated associations between single-nucleotide polymorphisms (SNPs) of the SMAP1L gene and AIA.We conducted an association study between 19 SNPs of the SMAP1L gene and AIA in a total of 592 Korean subjects including 163 AIA and 429 aspirin-tolerant asthma (ATA) patients. Associations between polymorphisms of SMAP1L and AIA were analyzed with sex, smoking status, atopy, and body mass index as covariates.Logistic analyses revealed that three common polymorphisms, rs2982510, rs2294752, and rs446738, were putatively associated with the increased susceptibility to AIA (p = .003, p(corr) = .004, OR = 0.24, 95% CI = 0.09-0.62 for rs2982510 and rs2294752; p = .008, p(corr) = .03, OR = 0.44, 95% CI = 0.24-0.80 for rs446738, in the recessive model). In addition, rs2982510 and rs2294752 were significantly associated with the fall of forced expiratory volume in 1 s (FEV₁) by aspirin provocation (p = .001, p(corr) = .04 in the recessive model for both SNPs).Our findings suggest that SMAP1L might be a susceptible gene to AIA, providing a new strategy for the control of aspirin intolerance.

The kinesin family number 3A (KIF3A) gene on the human chromosomal 5q31-33 region, which is known as a susceptibility locus for immune diseases including asthma, plays a crucial role in generation of cilia.A treatment with aspirin in the human bronchial epithelial cells increased the mRNA expression level of KIF3A compared to that of the untreated control (P ≤ 0.01), and nasal polyp epithelia from aspirin-intolerant asthma (AIA) patients also showed a higher expression of KIF3A protein than aspirin-tolerant asthma controls. Further logistic analyses revealed that most polymorphisms of KIF3A were significantly associated with AIA (P = 0.0004-0.02; P(corr) = 0.004-0.04) and the decline of forced expiratory volume at 1 s (FEV(1))% by aspirin provocation (P = 0.004-0.04; P(corr) = 0.03).Our findings suggest that the KIF3A gene and/or its polymorphisms might have a susceptibility effect on AIA, providing a new step toward controlling aspirin intolerance in asthmatics.

Aims: Cysteinyl leukotrienes are inactivated by acetyl coenzyme A-dependent N-acetyltransferase (NAT). Thus, functional alterations of the NAT gene may contribute to the risk of aspirin-intolerant asthma. Materials & methods: Asthmatics (n = 438) were categorized into aspirin-intolerant asthma (15% or greater decrease in the forced expiratory volume in 1 s or cutaneous reactions, n = 170) or aspirin-tolerant asthma (n = 268) groups. In total, 14 polymorphisms of the NAT2 gene were genotyped by a single-base extension method. Results: The distributions of all loci of the 14 SNPs were in Hardy–Weinberg equilibrium (p > 0.05). Among the 14 SNPs, six common SNPs (minor allele frequency >5%) in a Korean population were used for haplotype construction and further statistical analysis. The logistic regression analysis demonstrated that NAT2 -9246G>C and haplotype 2 (TCACGG) were significantly associated with the risk of aspirin-intolerant asthma. The rare allele frequencies of the SNP and Ht2 were significantly higher in the aspirin-intolerant asthma group than in the aspirin-tolerant asthma group (pcorr = 0.03 and pcorr = 0.02 in codominant model). Conclusion: In a large genetic epidemiology study of aspirin-intolerant asthma in a Korean population, genetic polymorphisms of NAT2 were found to be related to a risk of aspirin hypersensitivity among asthmatics.