Young Joo Cho

Insights, attitudes and perceptions about asthma and its treatment: Findings from a multinational survey of patients from 8 Asia-Pacific countries and Hong Kong

The Asthma Insight and Management (AIM) survey was conducted in North America, Europe, the Asia‐Pacific region and Latin America to characterize patients’ insights, attitudes and perceptions about their asthma and its treatment. We report findings from the Asia‐Pacific survey.

IL-33 induces Th17-mediated airway inflammation via mast cells in ovalbumin-challenged mice

Allergic asthma is characterized by infiltration of eosinophils, elevated Th2 cytokine levels, airway hyperresponsiveness, and IgE. In addition to eosinophils, mast cells, and basophils, a variety of cytokines are also involved in the development of allergic asthma. The pivotal role of eosinophils in the progression of the disease has been a subject of controversy. To determine the role of eosinophils in the progression of airway inflammation, we sensitized and challenged BALB/c wild-type (WT) mice and eosinophil-deficient ΔdblGATA mice with ovalbumin (OVA) and analyzed different aspects of inflammation. We observed increased eosinophil levels and a Th2-dominant response in OVA-challenged WT mice. In contrast, eosinophil-deficient ΔdblGATA mice displayed an increased proportion of mast cells and a Th17-biased response following OVA inhalation. Notably, the levels of IL-33, an important cytokine responsible for Th2 immune deviation, were not different between WT and eosinophil-deficient mice. We also demonstrated that mast cells induced Th17-differentiation via IL-33/ST2 stimulation in vitro. These results indicate that eosinophils are not essential for the development of allergic asthma and that mast cells can skew the immune reaction predominantly toward Th17 responses via IL-33 stimulation.

Insights, attitudes and perceptions about asthma and its treatment

The Asthma Insight and Management (AIM) survey was conducted in North America, Europe, the Asia‐Pacific region and Latin America to characterize patients’ insights, attitudes and perceptions about their asthma and its treatment. We report findings from the Asia‐Pacific survey.

Effects of Interleukin-9 Blockade on Chronic Airway Inflammation in Murine Asthma Models

Purpose Asthma is a chronic inflammatory disease of the airways associated with structural changes and airway remodeling. Interleukin (IL)-9 has pleiotropic effects on both inflammatory cells and airway structural cells, which are involved in asthma pathogenesis. We evaluated the effects of IL-9 blockade on chronic airway inflammation. Methods Acute airway inflammation was induced in Balb/c mice using aerosolized ovalbumin (OVA), whereas chronic asthma was induced by OVA exposure for 5 weeks with anti-IL-9 or isotype-matched antibody (Ab) treatment during the OVA challenge. Inflammatory cells in bronchoalveolar lavage fluid (BALF) were counted and lung tissues were stained to detect cellular infiltration, mucus deposition, and collagen accumulation. The levels of interferon (IFN)-γ, IL-4, IL-5, IL-9, IL-17, and immunoglobulin E (IgE) in BALF were measured using enzyme linked immunosorbent assays, and profiles of inflammatory cells and subsets of T helper (Th) cells were analyzed using flow cytometry. Results IL-9, IL-17, and IFN-γ levels were significantly increased in the chronic group compared to the acute asthma group. However, the number of IL-9-positive cells was not affected, with a decrease in Th17 cells in OVA-challenged caspase-1 knockout mice. Numbers of eosinophils, neutrophils, B cells, mast cells, and Th17 cells decreased after administration of anti-IL-9 Ab. Total IgE, IL-5, IL-9, and IL-17 levels were also lower in the anti-IL-9 group. Conclusions Our results suggest that anti-IL-9 Ab treatment inhibits pulmonary infiltration of inflammatory cells and cytokine production, especially IL-17. These results provide a basis for the use of an anti-IL-9 Ab to combat IL-17-mediated airway inflammation.

Flow Cytometry-Assisted Basophil Activation Test as a Safe Diagnostic Tool for Aspirin/NSAID Hypersenstivity

Purpose Aspirin and non-steroidal anti-inflammatory drugs (ASA/NSAIDs) are common causes of drug hypersensitivity. An oral provocation test is the only definitive diagnostic test. This study assessed the reliability of a flow cytometry-assisted basophil activation test (FAST) as a safe diagnostic method for ASA/NSAID-induced hypersensitivity, as its high sensitivity and specificity have been demonstrated for many other drugs. Methods Eighteen patients and 11 controls were enrolled. Using a Flow-CAST kit® (Bühlmann Laboratories AG, Schönenbuch, Switzerland), 29 analyses with aspirin, ibuprofen, and diclofenac were performed by flow cytometry to detect double-positive staining of anti-IgE and anti-CD63. The stimulation index was defined as the activated basophil percentage after drug stimulation/basally active basophil percentage. A stimulation index≥2 and an absolute activated basophil percentage≥5 were considered positive. Results Patients with hypersensitivity to ASA/NSAIDs were predominantly female, and the prevalence of atopy was higher in patients than in controls. A sensitivity of 61%, specificity of 91%, positive predictive value of 92%, and negative predictive value of 59% were achieved. Conclusions FAST is a useful additional method for diagnosis of hypersensitivity reactions to ASA/NSAIDs. Further development is required to increase the sensitivity of the test.

A Metagenomic Analysis Provides a Culture-Independent Pathogen Detection for Atopic Dermatitis

Purpose Atopic dermatitis (AD) is an inflammatory skin disease, significantly affecting the quality of life. Using AD as a model system, we tested a successive identification of AD-associated microbes, followed by a culture-independent serum detection of the identified microbe. Methods A total of 43 genomic DNA preparations from washing fluid of the cubital fossa of 6 healthy controls, skin lesions of 27 AD patients, 10 of which later received treatment (post-treatment), were subjected to high-throughput pyrosequencing on a Roche 454 GS-FLX platform. Results Microbial diversity was decreased in AD, and was restored following treatment. AD was characterized by the domination of Staphylococcus, Pseudomonas, and Streptococcus, whereas Alcaligenaceae (f), Sediminibacterium, and Lactococcus were characteristic of healthy skin. An enzyme-linked immunosorbent assay (ELISA) showed that serum could be used as a source for the detection of Staphylococcus aureus extracellular vesicles (EVs). S. aureus EV-specific immunoglobulin G (IgG) and immunoglobulin E (IgE) were quantified in the serum. Conclusions A metagenomic analysis together with a serum detection of pathogen-specific EVs provides a model for successive identification and diagnosis of pathogens of AD.

RhoA-mediated signaling up-regulates hepatocyte growth factor gene and protein expression in response to apoptotic cells.

Clearance of apoptotic cells by macrophages induces HGF secretion. We examined the regulatory mechanisms of HGF mRNA and protein expression in macrophages upon exposure to apoptotic cells. The interaction of RAW 264.7 macrophages with apoptotic Jurkat cells, but not with viable cells, resulted in expression of HGF mRNA and protein. Exposure of RAW 264.7 cells to apoptotic cells induced activation of RhoA, the PI3K/Akt pathway, and MAPKs, including p38 MAPK, ERK, and JNK. Down‐regulation of the RhoA/Rho kinase pathway by pharmacological inhibitors or a RhoA‐specific siRNA suppressed HGF mRNA and protein expression by macrophages in response to apoptotic cells through the phosphorylation of Akt and the MAPKs. Inhibition of PI3K decreased phosphorylation of Akt and the MAPKs. Inhibition of JNK, but not p38 MAPK and ERK, reduced Akt phosphorylation. The pharmacological inhibitor of PI3K and the MAPKs blocked HGF mRNA and protein expression. Other types of apoptotic cells, such as HeLa cells and murine thymocytes, could also induce HGF mRNA through the RhoA‐dependent pathway. Likely, the RhoA‐dependent signaling pathway was required for HGF mRNA induction in primary cells of peritoneal macrophages in response to apoptotic cells. An HGFR‐blocking antibody did not alter apoptotic cell‐induced activation of RhoA, Akt, and the MAPKs, as well as HGF production. Overall, the data provide evidence that activation of the RhoA/Rho kinase pathway up‐regulates transcriptional HGF production in response to apoptotic cells.

House Dust Mite-Derived Chitin Enhances Th2 Cell Response to Inhaled Allergens, Mainly via a TNF-α-Dependent Pathway

Purpose Chitin is a potent adjuvant in the development of immune response to inhaled allergens in the airways. According to other studies, chitin is known as multi-faced adjuvants which can induce Th2 responses. Recently, we found that TNF-α is a key mediator in the development of Th2 cell response to inhaled allergens. Here, we evaluated the immunologic mechanisms in the development of airway hypersensitivity to inhaled allergens, enhanced by house dust mite (HDM)-derived chitin. Methods The role of TNF-α and TLRs was evaluated in an airway hypersensitivity mouse model induced by a sensitization with an allergen (ovalbumin, OVA) and HDM-derived chitin using mice with the null mutation of target genes. Results The present study showed that airway sensitization with HDM-derived chitin plus OVA enhanced OVA-induced airway inflammation v. OVA alone. This phenotype was associated with the increased expression of Th1, Th2, and Th17 cytokines and also with the enhanced production of OVA-specific IgE, IgG1, and IgG2a. As for T cell responses, OVA-specific Th2 cell response, enhanced by chitin, was abolished by the treatment of chitinase, whereas Th1 and Th17 cell responses enhanced by this treatment. Moreover, the null mutation of the TNF-α gene revealed similar effects as the chitinase treatment. In contrast, all the OVA-specific T cell responses, enhanced by chitin, were blocked by the absence of TLR2, but not of TLR1, TLR4, or TLR6. Conclusions In conclusion, these data suggest that HDM-derived chitin may enhance airway hypersensitivity to inhaled allergens, via the TLR2-dependent pathway, and that chitin-induced TNF-α can be a key mediator in the development of Th2 cell response to inhaled allergens.

A Randomized, Multicenter, Double-blind, Phase III Study to Evaluate the Efficacy on Allergic Rhinitis and Safety of a Combination Therapy of Montelukast and Levocetirizine in Patients With Asthma and Allergic Rhinitis

PURPOSE The aim of this study was to evaluate the efficacy and safety of a fixed-dose combination of montelukast and levocetirizine in patients with perennial allergic rhinitis with mild to moderate asthma compared with the efficacy and safety of montelukast alone. METHODS This study was a 4-week, randomized, multicenter, double-blind, Phase III trial. After a 1-week placebo run-in period, the subjects were randomized to receive montelukast (10 mg/day, n = 112) or montelukast (10 mg/day)/levocetirizine (5 mg/day) (n = 116) treatment for 4 weeks. The primary efficacy end point was mean daytime nasal symptom score. Other efficacy end points included mean nighttime nasal symptom score, mean composite symptom score, overall assessment of allergic rhinitis by both subjects and physicians, forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), FEV1/FVC, asthma control test score, and the frequency of rescue medication used during the treatment period. FINDINGS Of 333 patients screened for this study, 228 eligible patients were randomized to treatment. The mean (SD) age of patients was 43.32 (15.02) years, and two thirds of subjects were female (66.67%). The demographic characteristics were similar between the treatment groups. Compared with the montelukast group, the montelukast/levocetirizine group reported significant reductions in mean daytime nasal symptom score (least squares mean [SE] of combination vs montelukast, -0.98 [0.06] vs -0.81 [0.06]; P = 0.045). For all other allergic rhinitis efficacy end points, the montelukast/levocetirizine group showed greater improvement than the montelukast group. Similar results were observed in overall assessment scores and in FEV1, FVC, FEV1/FVC, and asthma control test score changes from baseline for the 2 treatment groups. Montelukast/levocetirizine was well tolerated, and the safety profile was similar to that observed in the montelukast group. IMPLICATIONS The fixed-dose combination of montelukast and levocetirizine was effective and safe in treating perennial allergic rhinitis in patients with asthma compared with montelukast alone. ClinicalTrials.gov identifier: NCT02552667.

294 Reference Values and Influencing Factors of Exhaled Nitric Oxide in Healthy Korean Adults.

Background Fractional exhaled nitric oxide (FeNO) is widely used as an inflammatory marker for asthma. However, reference values and influencing factors of FeNO using Niox Mino, which is the only device achieving US FDA approval, are not well described in healthy Asian adults. This study aimed to suggest the reference values and influencing factors of FeNO in healthy Korean adults. Methods Subjects who were over 19 years old and did not have any history of rhinitis, asthma or recent respiratory symptoms were enrolled. FeNO levels were measured using Niox Mino. Age, gender, body mass index (BMI), smoking status and lung function were also measured to analyze factors associated with FeNO levels. Results The mean value of FeNO was 16.14 ± 10.04 ppb. The reference value of FeNO, which was defined as the value of 95% in distribution curve, was same or less than 34 ppb. In a univariate analysis, FeNO levels were not associated with age, BMI and smoking history. However, atopy status (18.2 ± 11.8 for atopy and 15.1 ± 8.5 for nonatopy groups, P = 0.008) and gender (17.8 ± 10.2 for male and 14.8 ± 9.8 for female groups, P < 0.001) were positively associated with FeNO levels. In stratified analysis, the significance of both variables remained unchanged (P < 0.001). Conclusions Our data suggested that the reference value of FeNO in healthy Korean adults seemed to be same or less than 34 ppb. Reference values of FeNO in Korean adults are influenced by gender and atopy status.