Innate lymphoid cell population distributions and related gene expression characteristics in blood from allergic and nonallergic patients with eosinophilic asthma.

BACKGROUND: Non-allergic eosinophilic asthma (NAEA) is a distinct subtype of asthma. However, the immune mechanisms associated with NAEA are not yet clearly understood. OBJECTIVE: To gain further insight into the pathogenesis of NAEA. METHODS: The proportion of innate lymphoid cells (ILCs) in the blood of patients with allergic eosinophilic asthma (AEA) and NAEA was evaluated. Eosinophilic asthma was defined when fractional exhaled nitric oxide measured at diagnosis (before initiating anti-asthma medications) was greater than 50 ppb. We evaluated the genome-wide gene expression profiles in peripheral blood mononuclear cells obtained at enrollment (in a stable state). RESULTS: A total of 57 participants were enrolled (10 healthy controls, 23 patients with NAEA, and 24 patients with AEA). We found that the type 1 ILC (ILC1) proportion significantly decreased, but the type 2 ILC (ILC2) and type 3 ILC (ILC3) proportions significantly increased in the blood of both patients with NAEA and those with AEA compared with healthy controls. However, there were no significant differences in the ILC1~3 proportions between NAEA and AEA patients. We also identified distinct biological pathways in patients with NAEA (anti-viral pathway) or AEA (IL-4 and IL-13 signaling and neutrophil degranulation pathways) based on co-expressed gene modules showing significant correlations with the ILC proportions. CONCLUSION: ILC proportions in the blood did not differ between NAEA and AEA patients. However, different biological pathways were related to the ILC proportions in these patients. Our results provide further insight into eosinophilic airway inflammation in allergic and non-allergic patients.

Computed tomography-based measurements associated with rapid lung function decline in severe asthma.

BACKGROUND: Patients with severe asthma are susceptible to lung function decline (LFD), but biomarkers that reliably predict an accelerated LFD have not been fully recognized. OBJECTIVE: To identify variables associated with previous LFD occurrences in patients with severe asthma by exploring the computed tomography (CT) imaging features within predefined LFD groups. METHODS: We obtained inspiratory and expiratory CT images of 102 patients with severe asthma and derived 2 airway structural parameters (wall thickness [WT] and hydraulic diameter) and 2 parenchymal variables (functional small airway disease and emphysema). We retrospectively calculated the annual changes in forced expiratory volume in 1 second and grouped participants by their values determined. The 4-imaging metrics, along with levels of several biomarkers, were compared among the LFD groups. RESULTS: Patients with severe asthma with enhanced LFD exhibited significantly lower WT and smaller hydraulic diameter compared with those with minimal change or slight decline in lung function, after an adjustment of smoking status. Conversely, CT-based percentages of emphysema and functional small airway disease did not significantly differ according to LFD. Furthermore, fractional exhaled nitric oxide (FeNO) level and the blood matrix metalloproteinase-9/TIMP metallopeptidase inhibitor 1 ratio were significantly higher in patients with severe asthma with enhanced LFD compared with those in the others. CONCLUSION: Lower WT on CT scans with increased FeNO that may represent increased airway inflammation significantly correlated with enhanced LFD in patients with severe asthma. Consequently, active management plans may help to attenuate LFD for patients with severe asthma with lower WT and high FeNO.

Relationship of computed tomography-based measurements with symptom perception and quality of life in patients with severe asthma.

BACKGROUND: Symptom perception and quality of life (QOL) are important domains for properly managing severe asthma. This study aimed to assess the relationship between airway structural and parenchymal variables measured using chest computed tomography (CT) and subjective symptom perception and QOL in patients with severe asthma enrolled in the Korean Severe Asthma Registry. METHODS: This study used CT-based objective measurements, including airway wall thickness (WT), hydraulic diameter, functional small airway disease (fSAD), and emphysematous lung (Emph), to assess their association with subjective symptom (cough, dyspnea, wheezing, and sputum) perception measured using the visual analog scale, and QOL measured by the Severe Asthma Questionnaire (SAQ). RESULTS: A total of 94 patients with severe asthma were enrolled in this study. The WT and fSAD% were significantly positively associated with cough and dyspnea, respectively. For QOL, WT and Emph% showed significant negative associations with the SAQ. However, there was no significant association between lung function and symptom perception or between lung function and QOL. CONCLUSION: Overall, WT, fSAD%, and Emph% measured using chest CT were associated with subjective symptom perception and QOL in patients with severe asthma. This study provides a basis for clarifying the clinical correlates of imaging-derived metrics and for understanding the mechanisms of respiratory symptom perception.

Neuromuscular blocking agent re-exposure in a retrospective cohort with neuromuscular blocking agent-associated anaphylaxis.

BACKGROUND: Neuromuscular blocking agents (NMBAs) are one of the most common causes of perioperative anaphylaxis. Although skin test positivity may help identify reactive NMBAs, it is unclear whether skin test negativity can guarantee the safety of systemically administered NMBAs. OBJECTIVE: This study aimed to evaluate the real-world safety of alternative NMBAs screened using skin tests in patients with suspected NMBA-induced anaphylaxis. METHODS: A retrospective cohort of suspected NMBA-induced anaphylaxis were recruited among patients at Seoul National University Hospital from June 2009 to May 2021, and their characteristics and outcomes were assessed. RESULTS: A total of 47 cases (0.017%) of suspected anaphylaxis occurred in 282,707 patients who received NMBAs. Cardiovascular manifestations were observed in 95.7%, whereas cutaneous findings were observed in 59.6%. Whereas 83% had a history of undergoing general anesthesia, 17% had no history of NMBA use. In skin tests, the overall positivity to any NMBA was 94.6% (81.1% to culprit NMBAs) and the cross-reactivity was 75.7%, which is related to the chemical structural similarity among NMBAs; the cross-reactivity and chemical structure similarity of rocuronium were 85.3% and 0.814, respectively, with vecuronium; this is in contrast to 50% and 0.015 with cisatracurium and 12.5% and 0.208 with succinylcholine. There were 15 patients who underwent subsequent surgery with a skin test-negative NMBA; whereas 80.0% (12/15) safely completed surgery, 20.0% (3/15) experienced hypotension. CONCLUSION: Similarities in chemical structure may contribute to the cross-reactivity of NMBAs in skin tests. Despite the high negative predictability of skin tests for suspected NMBA-induced anaphylaxis, the potential risk of recurrent anaphylaxis has not been eliminated.

Rapamycin Restores Different Patterns of Cytokine Expression to Dexamethasone Treatment on CD14++CD16+ Monocytes from Steroid-Resistant Asthma Patients.

OBJECTIVE: We aimed to investigate the differences in interleukin (IL)-10, IL-1ß, IL-6, and tumor necrosis factor (TNF)-α expression in lipopolysaccharide (LPS)-stimulated CD14++CD16+ monocytes obtained from asthmatics after dexamethasone or dexamethasone plus rapamycin treatments between clinical steroid responders (R) and non-responders (NR). METHODS: Cytokine expressions in LPS-stimulated CD14++CD16+ p-mammalian target of rapamycin (mTOR) monocytes from R and NR were determined using flow cytometry. RESULTS: IL-10high CD14++CD16+ p-mTOR population following LPS stimulation increased in the R group although decreased in the NR group with dexamethasone treatment. IL-1ßhigh population decreased in the R group although increased in the NR group. Rapamycin treatment after LPS and dexamethasone resulted in a significant increase in the IL-10high population and a significant decrease in the IL-1ßhigh population in the NR group. CONCLUSION: Dexamethasone treatment resulted in different patterns of change in cytokine expressions in LPS-stimulated CD14++CD16+ p-mTOR monocytes between the R and NR. mTOR inhibition can restore steroid responsiveness involving IL-10 and IL-1ß in CD14++CD16+ p-mTOR monocytes.

A Critical Systematic Review for Inhaled Corticosteroids on Lung Cancer Incidence: Not Yet Concluded Story.

BACKGROUND: To systematically review studies on inhaled corticosteroids (ICS) and lung cancer incidence in chronic airway disease patients. METHODS: We conducted electronic bibliographic searches on OVID-MEDLINE, EM- BASE, and the Cochrane Database before May 2020 to identify relevant studies. Detailed data on the study population, exposure, and outcome domains were reviewed. RESULTS: Of 4,058 screened publications, 13 eligible studies in adults with chronic obstructive pulmonary disease (COPD) or asthma evaluated lung cancer incidence after ICS exposure. Pooled hazard ratio and odds ratio for developing lung cancer in ICS exposure were 0.81 (95% confidence interval, 0.64 to 1.02; I2=95.7%) from 10 studies and 1.02 (95% confidence interval 0.50 to 2.07; I2=94.7%) from three studies. Meta-regression failed to explain the substantial heterogeneity of pooled estimates. COPD and asthma were variously defined without spirometry in 11 studies. Regarding exposure assessment, three and 10 studies regarded ICS exposure as a time-dependent and fixed variable, respectively. Some studies assessed ICS use for the entire study period, whereas others assessed ICS use for 6 months to 2 years within or before study entry. Smoking was adjusted in four studies, and only four studies introduced 1 to 2 latency years in their main or subgroup analysis. CONCLUSION: Studies published to date on ICS and lung cancer incidence had heterogeneous study populations, exposures, and outcome assessments, limiting the generation of a pooled conclusion. The beneficial effect of ICS on lung cancer incidence has not yet been established, and understanding the heterogeneities will help future researchers to establish robust evidence on ICS and lung cancer incidence.

Chronic viral hepatitis accelerates lung function decline in smokers.

Although hepatitis B virus (HBV) and hepatitis C virus (HCV) are hepatotrophic viruses, they may affect pulmonary diseases. The purpose of this study was to assess whether chronic viral hepatitis (CVH) infection was associated with a rapid decline in lung function. Repeated measurements of lung function were obtained from a well-curated health check-up database. A case was defined as an individual positive for HBsAg or anti-HCV antibody. A control was randomly selected (from the same dataset) after 1:1 matching in terms of age, sex, height, the body mass index, and smoking status. Separate analyses of non-smokers and smokers were performed. A total of 701 cases were enrolled (586 with HBV and 115 with HCV). In cross-sectional analysis, both forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) decreased significantly only in smokers (smoking cases vs. smoking controls) (adjusted p = 6.6 × 10-5 and adjusted p = 2.2 × 10-3, respectively). In longitudinal analysis, smoking cases showed significantly greater FEV1 and FVC decline rates than did smoking controls (adjusted p = 8.5 × 10-3 and adjusted p = 1.2 × 10-5, respectively). Such associations were particularly high in smoking cases at intermediate-to-high risk of hepatic fibrosis, as evaluated by the non-invasive Fibrosis-4 index. In summary, CVH was associated with both decreased lung function and accelerated lung function decline in smokers. A non-invasive measurement of hepatic fibrosis may be useful in predicting rapid lung function decline in smokers with CVH.

Transcriptome analysis of sputum cells reveals two distinct molecular phenotypes of "asthma and chronic obstructive pulmonary disease overlap" in the elderly.

BACKGROUND: Little is known about the pathogenesis of asthma and chronic obstructive pulmonary disease (COPD) overlap (ACO). This study examined the molecular phenotypes of ACO in the elderly. METHODS: A genome-wide investigation of gene expression in sputum cells from the elderly with asthma, ACO, or COPD was performed using gene set variation analysis (GSVA) with predefined asthma- or COPD-specific gene signatures. We then performed a subsequent cluster analysis using enrichment scores (ESs) to identify molecular clusters in the elderly with ACO. Finally, a second GSVA was conducted with curated gene signatures to gain insight into the pathogenesis of ACO associated with the identified molecular clusters. RESULTS: Seventy elderly individuals were enrolled (17 with asthma, 41 with ACO, and 12 with COPD). Two distinct molecular clusters of ACO were identified. Clinically, ACO cluster 1 (N = 23) was characterized by male and smoker dominance, more obstructive lung function, and higher proportions of both neutrophil and eosinophil in induced sputum compared to ACO cluster 2 (N = 18). ACO cluster 1 had molecular features similar to both asthma and COPD, with mitochondria and peroxisome dysfunction as important mechanisms in the pathogenesis of these diseases. The molecular features of ACO cluster 2 differed from those of asthma and COPD, with enhanced innate immune reactions to microorganisms identified as being important in the pathogenesis of this form of ACO. CONCLUSION: Recognition of the unique biological pathways associated with the two distinct molecular phenotypes of ACO will deepen our understanding of ACO in the elderly.

Analysis of Breakthrough Reactions in 1,143 Desensitization Procedures in a Single Tertiary Hospital Using a One-Bag Desensitization Protocol.

Background: Drug desensitization is helpful for patients who have experienced significant hypersensitivity reactions (HSRs) to antineoplastic agents. One-bag desensitization protocols, attracting attention in recent years, need to be validated on their safety and efficacy in a large number. Methods: One-bag desensitization procedures conducted from 2018 to 2020 were analyzed; their outcomes and the risk factors for breakthrough reactions (BTRs) were assessed in desensitization procedures to major drug types (platins, taxanes, and monoclonal antibodies). Results: A total of 1,143 procedures of one-bag desensitization were performed in 228 patients with 99% completion rate. BTRs occurred in 26% of the total desensitization procedures-34% in platins, 12% in taxanes, and 18% in mAbs. BTR occurrence rate decreased along the desensitization process with 80% of BTRs occurring within the 6th desensitization attempts. Severe BTR occurred more frequently with severe initial HSRs (1% in mild to moderate initial HSRs vs. 16% in severe). Severe initial HSR was also a significant risk factor for moderate to severe BTR in platins (odds ratio 1.56, 95% confidence interval [CI] 1.06-2.29, p = 0.025). The use of steroid was also associated with lower occurrence of moderate to severe BTR (odds ratio 0.50, 95% CI 0.35-0.72, p < 0.001). Conclusion: Most patients with HSRs to antineoplastic agents can safely receive chemotherapy through a one-bag desensitization protocol. Further studies on each drug with larger sample size can help verify the risk factors of BTRs and evaluate the efficacy of steroid premedication in improving the safety of desensitization in high-risk patients.

Targeting Chitinase 1 and Chitinase 3-Like 1 as Novel Therapeutic Strategy of Pulmonary Fibrosis.

Chitinase 1 (CHIT1) and chitinase 3-like-1 (CHI3L1), two representative members of 18-Glycosyl hydrolases family, are significantly implicated in the pathogenesis of various human diseases characterized by inflammation and remodeling. Notably, dysregulated expression of CHIT1 and CHI3L1 was noted in the patients with pulmonary fibrosis and their levels were inversely correlated with clinical outcome of the patients. CHIT1 and CHI3L1, mainly expressed in alveolar macrophages, regulate profibrotic macrophage activation, fibroblast proliferation and myofibroblast transformation, and TGF-ß signaling and effector function. Although the mechanism or the pathways that CHIT1 and CHI3L1 use to regulate pulmonary fibrosis have not been fully understood yet, these studies identify CHIT1 and CHI3L1 as significant modulators of fibroproliferative responses leading to persistent and progressive pulmonary fibrosis. These studies suggest a possibility that CHIT1 and CHI3L1 could be reasonable therapeutic targets to intervene or reverse established pulmonary fibrosis. In this review, we will discuss specific roles and regulatory mechanisms of CHIT1 and CHI3L1 in profibrotic cell and tissue responses as novel therapeutic targets of pulmonary fibrosis.

Validation of Practical Pathway in Patients With Anaphylaxis to Low Osmolar Contrast Media: A Retrospective Cohort Study.

BACKGROUND: An optimal strategy for choosing safe alternative low osmolar contrast media (LOCM) has not yet been established in patients with a history of LOCM-induced anaphylaxis. OBJECTIVES: To validate the practical pathway in patients with anaphylaxis to LOCMs and to compare 2 different doses of challenge testing with skin test-negative LOCM. METHODS: A retrospective cohort study was performed in patients with LOCM-induced anaphylaxis. Patients were challenged with intravenous LOCMs showing negativity in the skin test according to 2 different protocols: low-dose and high-dose (maximum dose 10 and 30 mL, respectively). Challenge-negative LOCMs were selected for use during computed tomography scans, and patients received intravenous pretreatment with 4 mg chlorpheniramine and 40 mg methylprednisolone. RESULTS: Of the 110 challenge tests, there were 4 (3.6%) positive challenges. Among 106 enhanced computed tomography scans performed using challenge-negative LOCMs, breakthrough reactions occurred in 8 (7.6%). Breakthrough reaction rates were not statistically different between the 2 protocols (8.9% and 6.0% in the low-dose challenge and the high-dose challenge, respectively). Compared with the low-dose protocol, the number needed to test of the high-dose challenge test decreased 2.5-fold. Moreover, none of the patients in the high-dose challenge group incurred severe reactions during computed tomography scans with challenge-negative LOCM, whereas 80% of reactions were severe in the low-dose challenge group. CONCLUSIONS: We validated a pathway consisting of a battery of skin testing to LOCMs and challenge with skin test-negative LOCM in patients with LOCM-induced anaphylaxis.

Allergic-like Hypersensitivity Reactions to Gadolinium-based Contrast Agents: An 8-year Cohort Study of 154 539 Patients.

Background With the widespread use of gadolinium-based contrast agents (GBCAs), the incidence of allergic-like hypersensitivity reactions (HSRs) to GBCAs is increasing. Research on the incidence and risk factors for HSRs to GBCAs is needed for their safe use. Purpose To determine the incidence of acute and delayed reactions to GBCAs and to discuss the risk factors and strategies for the prevention of HSRs to GBCAs. Materials and Methods All cases of HSRs to contrast media that occurred at the Seoul National University Hospital from July 1, 2012, to June 30, 2020, were assessed. Information including age, sex, GBCA type, onset, and severity of HSRs was retrospectively analyzed. Results Among the 331070 cases of GBCA exposure in 154539 patients, 1304 cases of HSRs (0.4%) were reported. Acute HSRs accounted for 1178 cases (0.4%), while 126 cases (0.04%) were delayed HSRs. While both premedication (odds ratio [OR] = 0.7, P = .041) and changing the type of GBCA (OR = 0.2, P < .001) showed preventative effects in patients with a history of acute HSRs, only premedication (OR = 0.2, P = .016) significantly reduced the incidence of HSRs in patients with a history of delayed reactions. The risk of an HSR to GBCA was higher in those with a history of an HSR to iodinated contrast media (OR = 4.6, P < .001). Conclusion The rate of hypersensitivity reactions (HSRs) to gadolinium-based contrast agents (GBCAs) was 0.4%. The absence of premedication, repeated exposures to the culprit GBCA, and a history of HSRs to iodinated contrast media and GBCAs were risk factors for HSRs to GBCAs. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Kallmes and McDonald in this issue.

Does the Use of Asthma-Controller Medication in Accordance with Guidelines Reduce the Incidence of Acute Exacerbations and Healthcare Costs?

BACKGROUND: In asthma, consistent control of chronic airway inflammation is crucial, and the use of asthma-controller medication has been emphasized. Our purpose in this study is to compare the incidence of acute exacerbation and healthcare costs related to the use of asthma-controller medication. METHODS: By using data collected by the National Health Insurance Review and Assessment Service, we compared one-year clinical outcomes and medical costs from July 2014 to June 2015 (follow-up period) between two groups of patients with asthma who received different prescriptions for recommended asthma-controller medication (inhaled corticosteroids or leukotriene receptor antagonists) at least once from July 2013 to June 2014 (assessment period). RESULTS: There were 51,757 patients who satisfied our inclusion criteria. Among them, 13,702 patients (26.5%) were prescribed a recommended asthma-controller medication during the assessment period. In patients using a recommended asthma-controller medication, the frequency of acute exacerbations decreased in the follow-up period, from 2.7% to 1.1%. The total medical costs of the controller group decreased during the follow-up period compared to the assessment period, from $3,772,692 to $1,985,475. Only 50.9% of patients in the controller group used healthcare services in the follow-up period, and the use of asthma-controller medication decreased in the follow-up period. CONCLUSION: Overall, patients using a recommended asthma-controller medication showed decreased acute exacerbation and reduced total healthcare cost by half.

Incidence and risk factors of late adverse reactions to low-osmolar contrast media: A prospective observational study of 10,540 exposures.

PURPOSE: To evaluate the incidence and risk factors of late adverse reactions (ARs) to non-ionic low-osmolar contrast media (LOCM). METHODS: The occurrence of late AR was monitored on day 1 and from day 7 to day 28 in all patients who received enhanced computed tomography using LOCM during a 5-week study period in a single tertiary hospital. Patients who experienced late AR were followed up for three years. RESULTS: Among the total 10,540 LOCM exposures, 315 ARs (3.0%) were reported; acute ARs occurred in 108 LOCM exposures (1.0%) and late ARs occurred in 207 LOCM exposures (2.0%) (90.9% within one week, 9.1% developed afterwards by day 20). Previous history of drug allergy (odds ratio [OR] = 4.59; 95% confidence interval [CI] 2.17-9.71) and allergic diseases (OR = 2.54; 95% CI 1.32-4.91) were risk factors of late ARs to LOCM. Although the recurrence rate was lowered with premedication from 8.5% to 1.7% (8/94 vs. 3/178; p = 0.016), LOCM change did not make difference compared to reuse of the culprit LOCM (2/38 vs. 9/234; p = 0.655). In patients with a history of late AR to LOCM, the risk of recurrent reactions decreased with longer time intervals between exposures (OR = 0.86; 95% CI: 0.77-0.97; p = 0.025) and with the use of antihistamine premedication (OR = 0.27; 95% CI: 0.06-0.99; p = 0.049). CONCLUSIONS: Late ARs to LOCM occurred mostly within one week. The use of premedication may be helpful in reducing the recurrence of late ARs.

Relationships between lung function decline and skeletal muscle and fat mass changes: a longitudinal study in healthy individuals.

BACKGROUND: The associations between long-term changes in body mass composition and decline in lung function in healthy adults are unknown. METHODS: Using a well-defined health check-up database, we first assessed individual longitudinal changes in muscle mass (MM) and fat mass (FM) measured via bioelectrical impedance analyses. Then we classified the enrolled individuals into five body composition groups according to their MM index (MMI) [MM (kg)/height (m)2 ] or FM index (FMI) [FM (kg)/height (m)2 ] change rate quartiles. Linear mixed models adjusted for age, smoking status, height, and body mass index were used to analyse the rate of forced expiratory volume in 1 s (FEV1) decline and body composition groups. RESULTS: A total of 15 476 middle-aged individuals (6088 women [mean age ± standard deviation: 50.74 ± 7.44] and 9388 men [mean age ± standard deviation: 49.36 ± 6.99]) were enrolled. The mean number of measurements was 6.96 (interquartile range [IQR]: 5-9) over an average follow-up period of 8.95 years (IQR: 6.73-11.10). Decrease in MMI was significantly associated with accelerated FEV1 decline in men only (P = 1.7 × 10-9 ), while increase in FMI was significantly associated with accelerated FEV1 decline in both women and men (P = 7.9 × 10-10 and P < 2.0 × 10-16 respectively). Linear mixed model analyses indicated that annual increase of 0.1 kg/m2 in MMI was related to accelerated FEV1 decline by 30.79 mL/year (95% confidence interval [CI]: 26.10 to 35.48 mL/year) in men. Annual increase of 0.1 kg/m2 in FMI was related to accelerated FEV1 decline by 59.65 mL/year in men (95% CI: 56.84 to 62.28 mL/year) and by 22.84 mL/year in women (95% CI: 18.95 to 26.74 mL/year). In body composition analysis, we found increase in MMI was significantly associated with attenuated FEV1 decline in men only (P = 1.7 × 10-9 ), while increase in FMI was significantly associated with accelerated FEV1 decline in both women and men (P = 7.9 × 10-10 and P < 2.0 × 10-16 respectively). Individuals characterized with gain MM combined with loss of FM were associated with the most favourable outcome (i.e. the smallest rate of decline in FEV1) in both women and men. In men, loss of FM over time is more closely related with attenuated FEV1 decline than change in MM (gain or loss). CONCLUSIONS: Change in body composition over time can be used to identify healthy middle-aged individuals at high risk for rapid FEV1 decline.

Lung function decline is associated with serum uric acid in Korean health screening individuals.

We performed a retrospective cohort study of 19,237 individuals who underwent at least three health screenings with follow-up periods of over 5 years to find a routinely checked serum marker that predicts lung function decline. Using linear regression models to analyze associations between the rate of decline in the forced expiratory volume in 1 s (FEV1) and the level of 10 serum markers (calcium, phosphorus, uric acid, total cholesterol, total protein, total bilirubin, alkaline phosphatase, aspartate aminotransferase, creatinine, and C-reactive protein) measured at two different times (at the first and third health screenings), we found that an increased uric acid level was significantly associated with an accelerated FEV1 decline (P = 0.0014 and P = 0.037, respectively) and reduced FEV1 predicted % (P = 0.0074 and P = 8.64 × 10-7, respectively) at both visits only in non-smoking individuals. In addition, we confirmed that accelerated forced vital capacity (FVC) and FEV1/FVC ratio declines were observed in non-smoking individuals with increased serum uric acid levels using linear mixed models. The serum uric acid level thus potentially predicts an acceleration in lung function decline in a non-smoking general population.

Pragmatic Randomized Controlled Trial for Stepping Down Asthma Controller Treatment in Patients Controlled with Low-Dose Inhaled Corticosteroid and Long-Acting ß2-Agonist: Step-Down of Intervention and Grade in Moderate Asthma Study.

BACKGROUND: Current asthma guidelines recommend stepping down controller treatment when the condition is well-controlled for a certain time. However, the optimal step-down strategy for well-controlled patients receiving a low-dose inhaled corticosteroid (ICS) with a long-acting ß2-agonist (LABA) remains unclear. OBJECTIVE: This study was a randomized, open-label, three-arm, parallel pragmatic trial comparing two kinds of step-down approaches for maintaining treatment. METHODS: Adults with asthma who were aged 18 years or older, and who had been stable with low-dose ICS/LABA for at least 3 months, were enrolled. Subjects (n = 225) were randomly allocated into one of three groups (maintaining low-dose ICS/LABA [G1], discontinuing LABA [G2], and reducing ICS/LABA to once daily [G3]), and were observed for 6 months. The primary end point was a change in Asthma Control Test (ACT) scores between randomization and the final 6-month follow-up. RESULTS: The change in ACT was analyzed in the per-protocol population; noninferiority was not demonstrated in either step-down group compared with the maintenance group (95% confidence interval of the difference, G2 vs G1 = -1.40-0.55; G3 vs G1 = -1.19-0.77). Although over 90% of patients were fine, higher rates of treatment failure were observed in step-down groups (G1: 0%; G2: 9.46%; and G3: 9.09%; P = .027). There were no significant differences between step-down approaches in terms of ACT change or treatment failure. CONCLUSIONS: Both step-down methods were not noninferior to maintenance of treatment. Step-down therapy can be attempted when patients are stable, but appropriate monitoring and supervision are necessary with precautions regarding loss of disease control.

Patients' experiences of asthma exacerbation and management: a qualitative study of severe asthma.

Exacerbation is a defining feature of severe asthma, and oral corticosteroids (OCSs) are frequently prescribed to manage exacerbations. This qualitative study was conducted to examine the experience of patients with severe asthma, with a focus on asthma exacerbation and OCS treatment. Adults with severe asthma were recruited from three tertiary hospitals in South Korea. Data were collected through in-depth qualitative interviews. Verbatim transcripts were analysed using Colaizzi's phenomenological method to uncover the meaning of the participants' experience. Recruitment of participants continued until thematic saturation. 14 patients with severe asthma were recruited. Four theme clusters emerged: 1) experience of asthma exacerbation; 2) impact on life; 3) OCS treatments; and 4) disease perception. The patients experienced severe physical and psychosocial distress from asthma exacerbations, felt helpless due to failed efforts to prevent exacerbation and were living a restricted life due to fear of exacerbation. They feared OCS side-effects but had no other choice than to rely on OCSs because other interventions were ineffective. Most had poor knowledge and understanding of severe asthma and the long-term health consequences. Asthma exacerbation affects wide aspects of life in patients with severe asthma. Several components may underlie reliance on OCSs, including experience of distress during exacerbation, fear of future exacerbation and lack of proper knowledge about the long-term health consequences of severe asthma and OCS treatments. A multi-disciplinary approach is warranted to support the patients and to provide systematic education about the long-term health implications of severe asthma.

Different Biological Pathways Between Good and Poor Inhaled Corticosteroid Responses in Asthma.

Gene regulatory networks address how transcription factors (TFs) and their regulatory roles in gene expression determine the responsiveness to anti-asthma therapy. The purpose of this study was to assess gene regulatory networks of adult patients with asthma who showed good or poor lung function improvements in response to inhaled corticosteroids (ICSs). A total of 47 patients with asthma were recruited and classified as good responders (GRs) and poor responders (PRs) based on their responses to ICSs. Genome-wide gene expression was measured using peripheral blood mononuclear cells obtained in a stable state. We used Passing Attributes between Networks for Data Assimilations to construct the gene regulatory networks associated with GRs and PRs to ICSs. We identified the top-10 TFs that showed large differences in high-confidence edges between the GR and PR aggregate networks. These top-10 TFs and their differentially-connected genes in the PR and GR aggregate networks were significantly enriched in distinct biological pathways, such as TGF-ß signaling, cell cycle, and IL-4 and IL-13 signaling pathways. We identified multiple TFs and related biological pathways influencing ICS responses in asthma. Our results provide potential targets to overcome insensitivity to corticosteroids in patients with asthma.