Characterization of Codeine Treatment Responders Among Patients with Refractory or Unexplained Chronic Cough: A Prospective Real-World Cohort Study.

PURPOSE: Codeine is a narcotic antitussive often considered for managing patients with refractory or unexplained chronic cough. This study aimed to evaluate the proportion and characteristics of patients who responded to codeine treatment in real-world practice. METHODS: Data from the Korean Chronic Cough Registry, a multicenter prospective cohort study, were analyzed. Physicians assessed the response to codeine based on the timing and degree of improvement after treatment initiation. Follow-up assessments included the Leicester Cough Questionnaire and cough severity visual analog scale at six months. In a subset of subjects, objective cough frequency was evaluated following the initiation of codeine treatment. RESULTS: Of 305 patients, 124 (40.7%) responded to treatments based on anatomic diagnostic protocols, while 181 (59.3%) remained unexplained or refractory to etiological treatments. Fifty-one subjects (16.7%) were classified as codeine treatment responders (those showing a rapid and clear response), 57 (18.7%) as partial responders, and 62 (20.3%) as non-responders. Codeine responders showed rapid improvement in objective cough frequency and severity scores within a week of the treatment. At 6 months, responders showed significantly improved scores in cough scores, compared to non-responders. Several baseline parameters were associated with a more favorable treatment response, including older age, non-productive cough, and the absence of heartburn. CONCLUSIONS: Approximately 60% of chronic cough patients in specialist clinics may require antitussive drugs. While codeine benefits some, only a limited proportion (about 20%) of patients may experience rapid and significant improvement. This underscores the urgent need for new antitussive drugs to address these unmet clinical needs.

Clinical Relevance of Staphylococcus aureus Nasal Colonization and Staphylococcal Enterotoxin-Specific IgE Sensitization in Late-Onset Asthma.

This prospective observational study examined whether Staphylococcus aureus (SA) nasal colonization and staphylococcal enterotoxin (SE)-specific IgE sensitization synergistically affect clinical outcomes of adults with late-onset asthma (onset age ≥ 40 years). Nasal swabs were taken to evaluate SA colonization. Serum SE-IgE level was measured. Subjects were classified into 4 groups according to SA colonization and SE-IgE sensitization positivity. Among 181 patients with late-onset asthma recruited, the proportions of SA/SE (‒/‒), SA/SE (+ /‒), SA/SE (‒/ +), and SA/SE (+ / +) were 33.7%, 15.5%, 28.2%, and 22.6%, respectively. Severe asthma was more frequent in the SA/SE (+ / +) group than in the SA/SE (‒/‒) group (41.5% vs. 13.1%). The relationship of SA/SE (+ / +) with severe asthma was significant in multivariate logistic regression (vs. SA/SE (‒/‒); adjusted odds ratio: 4.36; 95% confidence intervals: 1.50‒12.73; p = 0.007), whereas SA/SE (+ /‒) or SA/SE (‒/ +) was not. In conclusion, SA nasal colonization and SE-IgE sensitization may synergistically affect disease severity in late-onset asthmatics.

A unique population of neutrophils generated by air pollutant-induced lung damage exacerbates airway inflammation.

BACKGROUND: Diesel exhaust particles (DEPs) are the main component of traffic-related air pollution and have been implicated in the pathogenesis and exacerbation of asthma. However, the mechanism by which DEP exposure aggravates asthma symptoms remains unclear. OBJECTIVE: This study aimed to identify a key cellular player of air pollutant-induced asthma exacerbation and development. METHODS: We examined the distribution of innate immune cells in the murine models of asthma induced by house dust mite and DEP. Changes in immune cell profiles caused by DEP exposure were confirmed by flow cytometry and RNA-Seq analysis. The roles of sialic acid-binding, Ig-like lectin F (SiglecF)-positive neutrophils were further evaluated by adoptive transfer experiment and in vitro functional studies. RESULTS: DEP exposure induced a unique population of lung granulocytes that coexpressed Ly6G and SiglecF. These cells differed phenotypically, morphologically, functionally, and transcriptionally from other SiglecF-expressing cells in the lungs. Our findings with murine models suggest that intratracheal challenge with DEPs induces the local release of adenosine triphosphate, which is a damage-associated molecular pattern signal. Adenosine triphosphate promotes the expression of SiglecF on neutrophils, and these SiglecF+ neutrophils worsen type 2 and 3 airway inflammation by producing high levels of cysteinyl leukotrienes and neutrophil extracellular traps. We also found Siglec8- (which corresponds to murine SiglecF) expressing neutrophils, and we found it in patients with asthma-chronic obstructive pulmonary disease overlap. CONCLUSION: The SiglecF+ neutrophil is a novel and critical player in airway inflammation and targeting this population could reverse or ameliorate asthma.

Effect of Acinetobacter lwoffii on the modulation of macrophage activation and asthmatic inflammation.

BACKGROUND: Although lung macrophages are directly exposed to external stimuli, their exact immunologic roles in asthma are still largely unknown. The aim of this study was to investigate the anti-asthmatic effect of Acinetobacter lwoffii in terms of lung macrophage modulation. METHODS: Six-week-old female BALB/c mice were sensitized and challenged with ovalbumin (OVA) with or without intranasal administration of A. lwoffii during the sensitization period. Airway hyperresponsiveness and inflammation were evaluated. Using flow cytometry, macrophages were subclassified according to their activation status. In the in vitro study, a murine alveolar macrophage cell line (MH-S) treated with or without A. lwoffii before IL-13 stimulation were analysed by quantitative RT-PCR. RESULTS: In a murine asthma model, the number of inflammatory cells, including macrophages and eosinophils, decreased in mice treated with A. lwoffii (A. lwoffii/OVA group) compared with untreated mice (OVA group). The enhanced expression of MHCII in macrophages in the OVA group was decreased by A. lwoffii treatment. M2 macrophage subtypes were significantly altered. A. lwoffii treatment decreased CD11b+ M2a and CD11b+ M2c macrophages, which showed strong positive correlations with Th2 cells, ILC2 and eosinophils. In contrast, CD11b+ M2b macrophages were significantly increased by A. lwoffii treatment and showed strong positive correlations with ILC1 and ILC3. In vitro, A. lwoffii down-regulated the expression of M2 markers related but up-regulated those related to M2b macrophages. CONCLUSIONS AND CLINICAL RELEVANCE: Intranasal A. lwoffii exposure suppresses asthma development by suppressing the type 2 response via modulating lung macrophage activation, shifting M2a and M2c macrophages to M2b macrophages.

Peripheral blood transcriptomic clusters uncovered immune phenotypes of asthma.

BACKGROUND: Transcriptomic analysis has been used to elucidate the complex pathogenesis of heterogeneous disease and may also contribute to identify potential therapeutic targets by delineating the hub genes. This study aimed to investigate whether blood transcriptomic clustering can distinguish clinical and immune phenotypes of asthmatics, and microbiome in asthmatics. METHODS: Transcriptomic expression of peripheral blood mononuclear cells (PBMCs) from 47 asthmatics and 21 non-asthmatics was measured using RNA sequencing. A hierarchical clustering algorithm was used to classify asthmatics. Differentially expressed genes, clinical phenotypes, immune phenotypes, and microbiome of each transcriptomic cluster were assessed. RESULTS: In asthmatics, three distinct transcriptomic clusters with numerously different transcriptomic expressions were identified. The proportion of severe asthmatics was highest in cluster 3 as 73.3%, followed by cluster 2 (45.5%) and cluster 1 (28.6%). While cluster 1 represented clinically non-severe T2 asthma, cluster 3 tended to include severe non-T2 asthma. Cluster 2 had features of both T2 and non-T2 asthmatics characterized by the highest serum IgE level and neutrophil-dominant sputum cell population. Compared to non-asthmatics, cluster 1 showed higher CCL23 and IL1RL1 expression while the expression of TREML4 was suppressed in cluster 3. CTSD and ALDH2 showed a significant positive linear relationship across three clusters in the order of cluster 1 to 3. No significant differences in the diversities of lung and gut microbiomes were observed among transcriptomic clusters of asthmatics and non-asthmatics. However, our study has limitations in that small sample size data were analyzed with unmeasured confounding factors and causal relationships or function pathways were not verified. CONCLUSIONS: Genetic clustering based on the blood transcriptome may provide novel immunological insight, which can be biomarkers of asthma immune phenotypes. Trial registration Retrospectively registered.

Association between obesity and lung function changes by sex and age in adults with asthma.

OBJECTIVE: The lung function changes presenting before and after asthma treatment in obese people remain largely unknown. This study aimed to investigate the association between obesity and lung function changes before and after treatment in adults with asthma. METHODS: We enrolled 937 newly diagnosed asthma patients from Cohort for Reality and Evolution of Adult Asthma in Korea cohort in 2015-2017, who performed follow-up spirometry after three months of asthma treatment. The percentage changes (Δ) between the spirometry results before and after treatment were calculated. Patients were categorized into four body mass index (BMI) groups; underweight (<18.5), normal (18.5-22.9), overweight (23.0-24.9), and obese (≥25.0). Association between percent change of pulmonary function and BMI was analyzed according to sex and/or age (< 45 yrs, 45-65 yrs, ≥ 65 yrs), which were statistically corrected for age, sex, smoking status, and medication history. RESULTS: There was no consistent correlation between BMI and each lung function parameter. However, there were significant differences between BMI and ΔFEV1/FVC before and after 3 months of controller treatment. The obese asthmatics showed significantly lower ΔFEV1/FVC (6.0 ± 13.5%) than the underweight (12.6 ± 21.4%, P = 0.044) or normal weight (9.1 ± 14.6%, P = 0.031). Middle-aged women had higher BMI (24.11 ± 3.60 vs. 22.39 ± 3.52) and lower ΔFEV1/FVC (5.7 ± 11.9% vs. 8.9 ± 14.3%, P = 0.012) than young women. CONCLUSIONS: Obesity is negatively correlated with the ΔFEV1/FVC before and after controller treatment. Sex and age differentially contribute to lung function changes in response to asthma medications in adult asthmatics, showing a significant decrease in the ΔFEV1/FVC in middle-aged women.

Clusters of Severe Eosinophilic Asthma in a Korean Asthma Cohort.

BACKGROUND: Targeted therapies have broadened the available treatment options for patients with severe eosinophilic asthma (SEA). However, differences in the magnitude of treatment responses among patients indicate the presence of various underlying pathophysiological processes and patient subgroups. OBJECTIVES: We aimed to describe the characteristics of SEA and identify its patient subgroups. METHODS: Clinical data from the Cohort for Reality and Evolution of Adult Asthma in Korea were analyzed. Cluster analysis was performed among those with SEA using 5 variables, namely, prebronchodilator forced expiratory volume in 1 s, body mass index, age at symptom onset, smoking amount, and blood eosinophil counts. RESULTS: Patients with SEA showed prevalent sensitization to aeroallergens, decreased lung function, and poor asthma control status. Cluster analysis revealed 3 distinctive subgroups among patients with SEA. Cluster 1 (n = 177) consisted of patients reporting the lowest blood eosinophils (median, 346.8 cells/µL) and modest severe asthma with preserved lung function during the 12-month treatment period. Cluster 2 (n = 42) predominantly included smoking males with severe persistent airway obstruction and moderate eosinophilia (median, 451.8 cells/µL). Lastly, cluster 3 (n = 95) included patients with the most severe asthma, the highest eosinophil levels (median, 817.5 cells/µL), and good treatment response in terms of improved lung function and control status. CONCLUSIONS: Three subgroups were identified in SEA through the cluster analysis. The distinctive features of each cluster may help physicians predict patients who will respond to biologics with greater magnitude of clinical improvement. Further research regarding the underlying pathophysiology and clinical importance of each subgroup is warranted.

Association Between Clinical Burden and Blood Eosinophil Counts in Asthma: Findings From a Korean Adult Asthma Cohort.

BACKGROUND: Some reports have suggested that the clinical and economic burdens of asthma are associated with blood eosinophil levels. The association between clinical burden and blood eosinophil counts were evaluated in a Korean adult asthma cohort. METHODS: Clinical information including blood eosinophil counts that were not affected by systemic corticosteroids were extracted from the Cohort for Reality and Evolution of Adult Asthma in Korea database. Clinical burden was defined as 1) asthma control status, 2) medication demand and 3) acute exacerbation (AE) events during 1 consecutive year after enrollment. All patients were divided into atopic and non-atopic asthmatics. The associations between asthma outcomes and the blood eosinophil count were evaluated. RESULTS: In total, 302 patients (124 atopic and 178 non-atopic asthmatics) were enrolled. In all asthmatics, the risk of severe AE was higher in patients with blood eosinophil levels < 100 cells/µL than in patients with levels ≥ 100 cells/µL (odds ratio [OR], 5.406; 95% confidence interval [CI], 1.266-23.078; adjusted P = 0.023). Among atopic asthmatics, the risk of moderate AE was higher in patients with blood eosinophil levels ≥ 300 cells/µL than in patients with levels < 300 cells/µL (OR, 3.558; 95% CI, 1.083-11.686; adjusted P = 0.036). Among non-atopic asthmatics, the risk of medication of Global Initiative for Asthma (GINA) steps 4 or 5 was higher in patients with high blood eosinophil levels than in patients with low blood eosinophil levels at cutoffs of 100, 200, 300, 400, and 500 cells/µL. CONCLUSION: The baseline blood eosinophil count may predict the future clinical burden of asthma.

Lung virome: New potential biomarkers for asthma severity and exacerbation.

BACKGROUND: Although some respiratory virus infections are known to contribute to the development and exacerbation of asthma, commensal viromes in airway have not been extensively studied due to technical challenges. OBJECTIVES: This study investigated the characteristics of the virome in asthmatic airways. METHODS: Both the bacteriome and virome profiles in sputum from 12 healthy individuals, 15 patients with nonsevere asthma, and 15 patients with severe asthma were analyzed and assessed for the association with clinical characteristics such as severity, exacerbation, Asthma Control Test (ACT), and lung function. RESULTS: While analysis of the 16S ribosomal RNA bacteriome in the airway showed no differences, clear contrasts in the diversity and composition of airway viromes were observed between healthy controls and patients with asthma. Herpesviruses were the most abundant type of virus in the asthma group (44.6 ± 4.6%), mainly with cytomegalovirus (CMV) and EBV accounting for 24.5 ± 3.3% and 16.9 ± 3.5%, respectively, in contrast to those in the healthy controls (5.4 ± 2.5% and 7.1 ± 3.0%, respectively). CMV and EBV were more abundant in patients with asthma who experienced exacerbation, and their abundance showed correlation with more severe asthma, lower ACT score, and lower lung function. On the contrary, bacteriophage that is abundant in healthy controls was severely reduced in patients with asthma in the order of nonsevere and severe asthma and presented significant positive correlation with ACT and FEV1/forced vital capacity. CONCLUSIONS: Lung viromes, especially, CMV, EBV, and bacteriophage may be potential biomarkers of asthma severity and exacerbation.

Characteristics of Specialist-Diagnosed Asthma-COPD Overlap in Severe Asthma: Observations from the Korean Severe Asthma Registry (KoSAR).

BACKGROUND: While the clinical characteristics and outcomes of asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) have been frequently compared with those of COPD or asthma, the prevalence and features of ACO in patients with severe asthma are unclear. OBJECTIVES: Evaluation of the prevalence and clinical features of ACO using the Korean severe asthma registry. METHODS: At the time of registration, ACO was determined in patients with severe asthma by attending specialists. Patients were classified into ACO and non-ACO groups, and the demographic and clinical characteristics of these two groups were compared. RESULTS: Of 482 patients with severe asthma, 23.7% had ACO. Patients in the ACO group were more likely to be male (P < .001), older (P < .001), and ex- or current smokers (P < .001) compared with those in the non-ACO group. Patients in the ACO group had lower mean forced expiratory volume in 1 second (P < .001) and blood eosinophil percentage (P = .006), but higher blood neutrophil percentage (P = .027) than those in the non-ACO group. The ACO group used more inhaled long-acting muscarinic antagonist (P < .001), methylxanthine (P = .001), or sustained systemic corticosteroid (P = .002). In addition, unscheduled emergency department visits due to exacerbation were more frequent in the ACO group (P = .006). CONCLUSION: Among patients with severe asthma, those with ACO were older, predominantly male, and were more likely to have a smoking history than those with asthma only. Patients with ACO used more systemic corticosteroid and had more frequent exacerbations related to emergency department visits than those with severe asthma only.

Discontinuation of inhaled corticosteroids in patients with controlled asthma: The DISCO (Discontinuation of Inhaled Steroid in Controlled asthmatics Over 6 months) study.

BACKGROUND: Although inhaled corticosteroids (ICSs) are the recommended first-line therapy for asthma, determining whether to continue or discontinue ICS treatment in patients with mild asthma remains challenging for clinicians. Several studies have revealed that patients with mild-persistent asthma maintained a well-controlled state after ICS withdrawal. However, the long-term outcomes of ICS withdrawal have not yet been determined. OBJECTIVE: To determine the possible clinical outcomes of the discontinuation of ICS in patients with well-controlled mild asthma. METHODS: We investigated the clinical outcomes of discontinuing ICSs in patients with well-controlled mild asthma and compared the time to loss of control (LOC) between patients who stopped ICS treatment (ICS withdrawal group, IWG) and those who continued treatment for 3 years (continuous ICS group, CIG). RESULTS: A significant difference in the time to LOC was observed between the IWG and CIG (hazard ratio, 2.56; 95% confidence interval, 1.52-4.33; P < .001). Increasing fractional exhaled nitric oxide levels (P = 0.008) and sputum eosinophil counts (%) (P = 0.015) revealed a weak but significant association with LOC risk in the CIG. The sputum eosinophil counts (P = 0.039) and serum total immunoglobulin E levels (P = 0.014) were significantly higher in the LOC group than in the non-LOC group of the CIG. CONCLUSION: Our results suggest that the maintenance of ICS treatment may help keep patients' asthma under control. Furthermore, patients with LOC had significantly higher sputum eosinophil counts in the CIG than those in the non-LOC group. Therefore, continuous ICS use by patients with mild, well-controlled asthma could be associated with good clinical outcomes. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: KCT0002234.

Transglutaminase 2 mediates lung inflammation and remodeling by transforming growth factor beta 1 via alveolar macrophage modulation.

Transforming growth factor beta 1 (TGF-ß1) induces pulmonary fibrosis by enhancing epithelial apoptosis and affects the enzymatic activity of transglutaminase 2 (TG2). The aim of this study was to determine the role of TG2 in TGF-ß1-induced lung remodeling and alveolar macrophage modulation. We characterized the in vivo effects of TGF-ß1 and TG2 on lung inflammation, fibrosis, and macrophage activity using transgenic C57BL/6 mice with wild and null TG2 loci. The effect of TG2 inhibition on in vitro TGF-ß1-stimulated alveolar macrophages was assessed through mRNA analysis. TG2 was remarkably upregulated in the lungs of TGF-ß1 transgenic (TGF-ß1 Tg) mice, especially in alveolar macrophages and epithelial cells. In the absence of TG2, TGF-ß1-induced inflammation was suppressed, decreasing the number of macrophages in the bronchoalveolar lavage fluid. In addition, the alveolar destruction and peribronchial fibrosis induced by TGF-ß1 overexpression were significantly reduced, which correlated with decreases in the expression of fibroblast growth factor and matrix metallopeptidase 12, respectively. However, TG2 deficiency did not compromise the phagocytic activity of alveolar macrophages in TGF-ß1 Tg mice. At the same time, TG2 contributed to the regulation of TGF-ß1-induced macrophage activation. Inhibition of TG2 did not affect the TGF-ß1-induced expression of CD86, an M1 marker, in macrophages, but it did reverse the TGF-ß1-induced expression of CD206. This result suggests that TG2 mediates TGF-ß1-induced M2-like polarization but does not contribute to TGF-ß1-induced M1 polarization. In conclusion, TG2 regulates macrophage modulation and plays an important role in TGF-ß1-induced lung inflammation, destruction, and fibrosis.

Novel tobacco products including electronic cigarette and heated tobacco products increase risk of allergic rhinitis and asthma in adolescents: Analysis of Korean youth survey.

BACKGROUND: The effect of novel tobacco products, such as electronic cigarettes (EC) and heated tobacco products (HTP), on allergic rhinitis (AR) and asthma is not well known. OBJECTIVE: To evaluate the health effect of novel tobacco products on asthma and AR. METHODS: This study was conducted using large survey data on Korean middle and high school students. The relationship between current asthma/AR and novel tobacco products user status was evaluated. In order to compare the combined effects of conventional cigarette (CC), EC, and HTP use on current allergic diseases, the participants were classified into 18 groups based on CC (current, former, and never), EC (current, former, and never), and HTP (ever and never) status. RESULTS: A total of 60,040 participants representing 2,850,118 Korean adolescents were analyzed. Of all participants, 6.7%, 2.7%, and 2.9% were current CC, current EC, and ever HTP users, respectively. Current CC and ever HTP use was significantly associated with current asthma and AR in adjusted models. Current EC showed association with current AR but the association with asthma disappeared in the adjusted model. Among 18 groups, the groups including current CC use showed higher risk of current AR and asthma than never HTP-never EC-never CC group. The odds ratio of current asthma especially increased more in those who used EC and/or HTP with CC concurrently than those in the never HTP-never EC-current CC user group. CONCLUSION: Using EC and/or HTP in adolescents might enhance the adverse effect of CC on AR and asthma.

Correction to: Immediate and delayed hypersensitivity after intra-arterial injection of iodinated contrast media: a prospective study in patients with coronary angiography.

The original version of this article, published on 01 April 2019, unfortunately contained a mistake. The presentation of Fig. 1 was incorrect. The corrected figure is given below.

Pharmacokinetic modeling analysis of cilostazol and its active metabolites (OPC-13015 and OPC-13213) after multiple oral doses of cilostazol in healthy Korean volunteers.

Cilostazol is a selective inhibitor of phosphodiesterase III (PDE III), which is prescribed for patients with peripheral arterial disease, especially intermittent claudication. The purpose of the study was to investigate the pharmacokinetic (PK) of cilostazol and its metabolites on the immediate (IR) formulation of cilostazol in healthy Korean male volunteers by population PK modeling analysis implemented using NONMEM software.A 2 × 2 crossover study comparing multiple oral doses of IR and SR formulations of cilostazol were conducted. Serial plasma concentrations of cilostazol and its active metabolites were used in this analysis.The PK was best depicted by one-compartment model, with absorption kinetics of cilostazol having mixed first- and zero-order kinetics with a time delay at the beginning of absorption. The introduction of interoccasion variabilities into zero-order (D1), first-order (Ka), and relative bioavailability (F1) significantly improved the model fit, and total body water (TBW) was identified as a significant covariate positively affecting the clearance of cilostazol. The model validation suggested that the model constructed in this study predicted the plasma concentration of cilostazol and its two active metabolites reasonably well.The PK model we developed explored the PK characteristics of cilostazol in Korean male subjects, and may be useful for identifying optimal individual dosing regimens of cilostazol.

Implementation of Asthma Management Guidelines and Possible Barriers in Korea.

BACKGROUND: There could be a gap between asthma management guidelines and current practice. We evaluated the awareness of and compliance with asthma management guidelines, and the internal and external barriers to compliance, for the first time in Korea. METHODS: From March to September of 2012, 364 physicians treating asthma patients at primary, secondary, and tertiary teaching hospitals were enrolled. They completed a questionnaire on the awareness of and compliance with asthma management guidelines, and the barriers and alternatives to their implementation. RESULTS: Of the 364 physicians, 79.1% were men and 56.9% were primary care physicians. The mean age was 40.5 ± 11.2 years. Most of them were aware of asthma management guidelines (89.3%). However, only a portion (11.0%) of them complied with the guidelines for asthma. Pulmonary function tests for diagnosis of asthma were performed by 20.1% of all physicians and 9.2% of primary care physicians, and by 9.9% of all physicians and 5.8% of primary care physicians for monitoring. Physicians stated that 'asthma monitoring' was the most difficult part of the guidelines, followed by 'environmental control and risk factors.' Only 39.6% (31.9% of the primary care physicians) prescribed an inhaled corticosteroid (ICS) as the first-line treatment for persistent asthma. The internal barriers were physician's preference for oral medications, difficulty in use even with inhaler training, and concern over ICS side effects. The external barriers were possible rejection of medical reimbursement by health insurance, refusal by the patient, cost, and a poor environment for teaching the patient how to use the inhaler. Alternatives proposed by physicians to implement asthma management guidelines were to improve medical reimbursement policies and the level of awareness of such guidelines. CONCLUSION: Compliance with the asthma management guidelines, including ICS prescription, is low despite the awareness of the guidelines. It is necessary to develop a strategy to overcome the internal and external barriers.

Innate immune crosstalk in asthmatic airways: Innate lymphoid cells coordinate polarization of lung macrophages.

BACKGROUND: Recent studies have emphasized the role of innate lymphoid cells (ILCs) in the development of asthma. The involvement of group 2 innate lymphoid cells (ILC2s) in asthma is well studied: however, the participation of other types of ILCs in the development of asthma remains unclear. OBJECTIVE: This study aims to understand the role of various ILCs in patients with asthma, especially their effect on macrophage polarization. METHODS: Each subset of ILCs and macrophages in induced sputum from 51 steroid-naive patients with asthma and 18 healthy donors was analyzed by using flow cytometry. Alveolar macrophages (AM) were sorted and cocultured with each subset of ILCs to determine whether the polarization of macrophages could be regulated by ILCs. RESULTS: In addition to ILC2s, numbers of group 1 innate lymphoid cells (ILC1s) and group 3 innate lymphoid cells (ILC3s) were increased in induced sputum from asthmatic patients when compared with those in healthy control subjects. The dominance of macrophages in induced sputum was more prominent in asthmatic patients than in healthy control subjects. A positive correlation between numbers of ILC2s and numbers of M2 macrophages and those of ILC1s/ILC3s and M1 macrophages was observed. Coculture of ILC2s with AMs induced expression of M2 macrophage-related genes, whereas coculture of ILC1s and ILC3s with AMs induced expression of M1 macrophage-related genes through cytokine secretion, as well as cell-cell contact. According to the inflammatory signature, patients with eosinophilic asthma have more ILC2s and M2 macrophages, and those with noneosinophilic asthma have an M1 macrophage-dominant profile. CONCLUSION: A different subset of ILCs regulates macrophage polarization, contributing to developing the distinct phenotype of asthma.

Cough persistence in adults with chronic cough: A 4-year retrospective cohort study.

BACKGROUND: There is very limited evidence regarding long-term prognosis of chronic cough. We examined longitudinal outcomes among patients with chronic cough, and explored predictors of cough persistence. METHODS: A retrospective cohort was constructed of adults who had newly visited a specialist cough clinic in 2012-2013. All had undergone systematic investigation for chronic cough. The Hull Airway Reflux Questionnaire (HARQ) was administered to assess reflux cough symptoms. A follow-up survey was conducted in 2016-2017 to assess cough persistence. RESULTS: From 418 candidates, 323 participated in the follow-up study; main analyses focused on patients with chronic persistent cough (n = 64; 19.8%) and remitted cough (n = 193; 59.8%). Compared with remitted cough group, chronic persistent cough group had more family history of chronic cough (17.2% vs. 4.7%, p = 0.001) and cold air-sensitive cough (62.5% vs. 44.6%, p = 0.013). The total HARQ score did not differ; however, two items (cough with eating and cough with certain foods) scored significantly higher in chronic persistent cough. In multivariate analyses, a family history of chronic cough (adjusted odds ratio 4.27 [95% confidence interval 1.35-9.89]), cold air-sensitive cough (2.01 [1.09-3.73]), and cough with eating (1.22 [1.02-1.45]) were associated with chronic persistent cough at 4 years. CONCLUSIONS: Cough persists in about 20% of patients after 4 years following systematic assessment and treatments. Several cough characteristics, such as family history, cold air-sensitivity, or reflux cough, may be associated with cough persistence. Larger cohort studies are warranted to further understand long-term prognosis and confirm predictors of persistence in patients with chronic cough.

Different upper airway microbiome and their functional genes associated with asthma in young adults and elderly individuals.

BACKGROUND: Microbes in the airway have been shown to be associated with the pathogenesis of asthma. The upper airway microbiome influences the dysbiosis of the lower airway microbiome. However, to date, the influence of upper airway microbiome for adult and elderly asthma has not been fully elucidated. Here, the metagenome of upper airway microbiome of young adults and elderly was analyzed to identify their association with adult asthma. METHODS: Nasopharyngeal swabs were collected from young adult and elderly asthma patients and non-asthmatic subjects. The compositions and functional genes of airway microbiome were analyzed by high-throughput sequencing. RESULTS: The composition of microbiota differed between young adult and elderly, and it was different between asthmatics and non-asthmatics in each age group. Different bacteria were related to FEV1% predicted in each age group. Genes related to lysine degradation, N-glycan biosynthesis, caprolactam degradation, and PPAR signaling pathway, which could be related to the reduction in inflammation and degradation of air pollutants, were higher in non-asthmatics. Genes related to pentose phosphate pathway, lipopolysaccharide biosynthesis, flagella assembly, and bacterial chemotaxis-which may all be related to increased inflammation and colonization of pathogenic bacteria-were higher in young adult asthmatic patients. However, the functional genes of airway microbiome in elderly patients were not significantly different according to asthma morbidity. CONCLUSIONS: These results suggest that the composition and function of upper airway microbiome could influence asthma pathogenesis, and the microbiome could play various roles depending on the age group.

Duration of Observation for Detecting a Biphasic Reaction in Anaphylaxis: A Meta-Analysis.

BACKGROUND: We conducted a meta-analysis to determine a practical observation time for detecting a biphasic reaction after resolution of the initial anaphylactic reaction. METHODS: A systematic literature search identified studies on adult patients with anaphylaxis and a subsequent biphasic reaction due to various causes that contained sufficient data to extract outcomes. The outcomes were pooled using a random-effects model. RESULTS: Twelve studies with a total of 2,890 adult patients with anaphylaxis and 143 patients with a biphasic reaction were included. In terms of the pooled negative predictive value, 1 h of observation achieved a 95.0% negative predictive value and ≥6 h of observation provided a 97.3% negative predictive value (95% CI: 95.0-98.5). The negative predictive value for a biphasic reaction increased with a longer observation time after initial anaphylaxis, and the increasing trend slowed down from 6 h of observation time. The pooled additional incidence rates of biphasic reactions per 100 person-hours after 1- and 4-h observations were 0.45 (95% CI: 0.20-1.04) and 0.41 (95% CI: 0.19-0.87), respectively. After > 8-12 h of postanaphylactic observation, the negative predictive value reached > 98%, while the additional incidence per 100 person-hours was < 0.10. CONCLUSIONS: An observation time of ≥6 h after resolution of an initial anaphylaxis symptom can exclude recurrence of a secondary reaction in > 95% of patients. Although longer observation periods resulted in the detection of more biphasic reactions, 6-12 h of observation time would be practical, supporting current relevant guidelines.