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Although asthma is a common chronic airway disease that responds well to anti-inflammatory agents, some patients with asthma are unresponsive to conventional treatment. Mesenchymal stem cells (MSCs) have therapeutic potential for the treatment of inflammatory diseases owing to their immunomodulatory properties. However, the target cells of MSCs are not yet clearly known. This study aimed to determine the effect of human umbilical cord-derived MSCs (hUC-MSCs) on asthmatic lungs by modulating innate immune cells and effector T cells using a murine asthmatic model. Intravenously administered hUC-MSCs reduced airway resistance, mucus production, and inflammation in the murine asthma model. hUC-MSCs attenuated not only T helper (Th) 2 cells and Th17 cells but also augmented regulatory T cells (Tregs). As for innate lymphoid cells (ILC), hUC-MSCs effectively suppressed ILC2s by downregulating master regulators of ILC2s, such as

Transforming growth factor beta 1 (TGF-β1) 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-β1-induced lung remodeling and alveolar macrophage modulation. We characterized the in vivo effects of TGF-β1 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-β1-stimulated alveolar macrophages was assessed through mRNA analysis. TG2 was remarkably upregulated in the lungs of TGF-β1 transgenic (TGF-β1 Tg) mice, especially in alveolar macrophages and epithelial cells. In the absence of TG2, TGF-β1-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-β1 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-β1 Tg mice. At the same time, TG2 contributed to the regulation of TGF-β1-induced macrophage activation. Inhibition of TG2 did not affect the TGF-β1-induced expression of CD86, an M1 marker, in macrophages, but it did reverse the TGF-β1-induced expression of CD206. This result suggests that TG2 mediates TGF-β1-induced M2-like polarization but does not contribute to TGF-β1-induced M1 polarization. In conclusion, TG2 regulates macrophage modulation and plays an important role in TGF-β1-induced lung inflammation, destruction, and fibrosis.

Background/Aims: Tuberculosis has incidence and mortality rates that are among the highest for all communicable diseases. Adverse drug reactions (ADRs) to anti-tubercular drugs are common, and have a major impact on treatment maintenance and prognosis. It is important to understand the characteristics of ADRs and establish a suitable management plan. Methods: We retrospectively reviewed patients with ADRs during treatment with first-line antitubercular drugs such as isoniazid, rifampicin, ethambutol, and pyrazinamide from 2009 to 2018. Age, sex, and total treatment period, and the onset, severity, seriousness, and system organ class of ADRs, were analyzed to understand the characteristics of first-line anti-tubercular drug-related ADRs. Results: A total of 1,606 of 5,482 patients (29.3%) experienced ADRs after administration of first-line anti-tubercular drugs. The incidence of ADRs related to isoniazid, rifampicin, ethambutol, and pyrazinamide was 22.2%, 21.3%, 24.5%, and 29.6%, respectively. A total of 2,098 ADR reports were made (mean of 1.3 ± 0.6 per patient). The rates of mild, moderate, and severe ADRs were 32.4%, 61.1%, and 6.5%, respectively. There were 127 reports (6.1%) of serious ADRs. Skin and appendage disorders were most frequently reported (27.5%), followed by gastrointestinal disorders (17.5%), and liver and biliary system disorders (13.1%). The total treatment period was longer in patients who experienced ADRs (224.0 ± 3.1 days vs. 247.0 ± 4.7 days, p = 0.009). Conclusions: The incidence of ADRs to first-line anti-tuberculosis drugs was 29.3%, and 6.5% were severe ADRS. ADRs prolonged the overall treatment duration, indicating the importance of their detection and management.

Background/Aims: Despite proper use of pharmaceuticals, adverse drug reactions (ADRs) can lead to problems related to patient safety. We analyzed the characteristics of ADRs, particularly serious adverse events (SAEs), in a single tertiary medical institution. Methods: Spontaneous ADR report data collected from 2010 to 2019 in Seoul National University Hospital were assessed. Causality was evaluated according to the World Health Organization-Uppsala Monitoring Centre criteria. Age, sex, onset, severity, seriousness, and system organ class (SOC) of ADRs and SAEs were analyzed. Results: During the study period, a total of 49,955 individual case safety reports were assessed as possible, probable, or certain. Although the number of gastrointestinal ADR reports was high (25.9%), severe cases were uncommon (2.6%). By contrast, the number of hematologic disorders was low (6.6%) but 39.2% of them were severe. Among ADRs, 10.2% were assessed as SAEs, the proportion of which was high at extreme ages and in males. Body as a whole-general disorders were the most frequently reported SOC for SAEs, followed by skin and appendage disorders. Antineoplastic agents and antibiotics were the most common causative agents of SAEs and ADRs. Anaphylactic reaction was the most frequent SAE (6.5%). Conclusions: The proportion of SAE differs according to SOC and drug. Attention should be paid to SAEs in children and older adults because the rate of SAEs is significantly higher at extreme ages.

This investigation studied the effect of reduction sequence during rolling of ferritic stainless steel on texture and anisotropy. A series of thermomechanical processes were performed on the present samples utilizing rolling deformation, with a total height reduction of 83% but with different reduction sequences, 67% + 50% (route A) and 50% + 67% (route B). Microstructural analysis showed that no significant difference was found in terms of the grain morphology between route A and route B. In terms of the texture, as compared to route A, route B developed a sharper texture on all components along the γ-fiber and a considerably higher fraction of boundaries that displayed 38°111 misorientations with respect to the surrounding deformed grains. In consequence, optimal deep drawing properties were achieved, where rm was maximized and Δr was minimized. Moreover, despite the similar morphology between the two processes, the resistance toward ridging was improved in the case of route B. This was explained in relation to the selective growth-controlled recrystallization, which favors the formation of microstructure with homogeneous distribution of the //ND orientation.

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.

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.

Foreign molecules, including viruses and bacteria-derived toxins, can also induce airway inflammation. However, to the best of our knowledge, the roles of these molecules in the development of airway inflammation have not been fully elucidated. Herein, we investigated the precise role and synergistic effect of virus-mimicking double-stranded RNA (dsRNA) and staphylococcal enterotoxin B (SEB) in macrophages and epithelial cells. To identify cytokine expression profiles, both the THP-1-derived macrophages and BEAS-2B epithelial cells were stimulated with dsRNA or SEB. A total of 21 cytokines were evaluated in the culture supernatants. We observed that stimulation with dsRNA induced cytokine production in both cell types. However, cytokine production was not induced in SEB-stimulated epithelial cells, compared to the macrophages. The synergistic effect of dsRNA and SEB was evaluated observing cytokine level and intracellular phospho-signaling. Fifteen different types were detected in high-dose dsRNA-stimulated epithelial cells, and 12 distinct types were detected in macrophages; those found in macrophages lacked interferon production compared to the epithelial cells. Notably, a synergistic effect of cytokine induction by co-stimulation of dsRNA and SEB was observed mainly in epithelial cells, via activation of most intracellular phosphor-signaling. However, macrophages only showed an accumulative effect. This study showed that the type and severity of cytokine productions from the epithelium or macrophages could be affected by different intensities and a combination of dsRNA and SEB. Further studies with this approach may improve our understanding of the development and exacerbation of airway inflammation and asthma.

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.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.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 CD11bIntranasal 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.

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.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.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 levels100 cells/µL than in patients with levels ≥ 100 cells/µL (odds ratio [OR], 5.406; 95% confidence interval [CI], 1.266-23.078; adjustedThe baseline blood eosinophil count may predict the future clinical burden of asthma.

Background: Asthma is a heterogeneous inflammatory airway disorder with various phenotypes. Quantitative computed tomography (QCT) methods can differentiate among lung diseases through accurate assessment of the location, extent, and severity of the disease. The purpose of this study was to identify asthma clusters using QCT metrics of airway and parenchymal structure, and to identify associations with visual analyses conducted by radiologists. Methods: This prospective study used input from QCT-based metrics including hydraulic diameter (Dh), luminal wall thickness (WT), functional small airway disease (fSAD), and emphysematous lung (Emph) to perform a cluster analysis and made comparisons with the visual grouping analysis conducted by radiologists based on site of airway involvement and remodeling evaluated. Results: A total of 61 asthmatics of varying severities were grouped into 4 clusters. From C1 to C4, more severe lung function deterioration, higher fixed obstruction rate, and more frequent asthma exacerbations were observed in the 5-year follow-up period. C1 presented non-severe asthma with increased WT, Dh of proximal airways, and fSAD. C2 was mixed with non-severe and severe asthmatics, and showed bronchodilator responses limited to the proximal airways. C3 and C4 included severe asthmatics that showed a reduced Dh of the proximal airway and diminished bronchodilator responses. While C3 was characterized by severe allergic asthma without fSAD, C4 included ex-smokers with high fSAD% and Emph%. These clusters correlated well with the grouping done by radiologists and clinical outcomes. Conclusions: Four QCT imaging-based clusters with distinct structural and functional changes in proximal and small airways can stratify heterogeneous asthmatics and can be a complementary tool to predict clinical outcomes.

Background Delayed hypersensitivity reactions (DHRs) to radiocontrast media (RCM) occur in approximately 0.5–23.0% of patients and are thought to be caused by T cell-mediated mechanisms. However, an optimal pharmacological preventive strategy is not yet established in patients with histories of delayed reactions to RCM. Objective We aimed to evaluate the efficacy of pharmacological prevention in patients with histories of delayed reactions to non-ionic low-osmolar RCM when re-exposed to RCM. Methods A retrospective review of electronic medical records of 117 patients with previous histories of DHRs to RCM who visited an allergy clinic for the prevention of reactions after the re-exposure to RCM was conducted. The effects of pharmacological prevention were compared according to the symptom scores of previous reactions based on their intensities and durations with electronic medical records (EMRs). Results Of the 117 patients who experienced DHRs after RCM injection, we confirmed the outcomes of RCM re-exposure in 101 patients. For pharmacological prevention, 92 patients (91.1%) received steroids before RCM injection and among them, 50 patients (49.5%) received additional steroids after RCM injection. With this pharmacological prevention, patients of symptoms improved or no recurrence, recurrence of similar previous symptoms, and recurrence of worse symptoms were 98 (97.0%), 2 (2.0%), and 1 (1.0%), respectively. The proportions of no recurrence after pharmacological prevention were lower in patients with severe reactions and higher symptom scores. Conclusion Pharmacological prevention showed a beneficial effect in most patients with delayed hypersensitivity to RCM. Further investigations are needed to establish an effective protocol for the prevention of delayed reactions to RCM.

Asthma is a heterogeneous disease whose development is shaped by a variety of environmental and genetic factors. While several recent studies suggest that microbial dysbiosis in the gut may promote asthma, little is known about the relationship between the recently discovered lung microbiome and asthma. Innate lymphoid cells (ILCs) have also been shown recently to participate in asthma. To investigate the relationship between the lung microbiome, ILCs, and asthma, we recruited 23 healthy controls (HC), 42 patients with non-severe asthma, and 32 patients with severe asthma. Flow cytometry analysis showed severe asthma associated with fewer natural cytotoxicity receptor (NCR)+ILC3s in the lung. Similar changes in other ILC subsets, macrophages, and monocytes were not observed. The asthma patients did not differ from the HC in terms of the alpha and beta-diversity of the lung and gut microbiomes. However, lung function correlated positively with both NCR+ILC3 frequencies and microbial diversity in the lung. Sputum NCR+ILC3 frequencies correlated positively with lung microbiome diversity in the HC, but this relationship was inversed in severe asthma. Together, these data suggest that airway NCR+ILC3s may contribute to a healthy commensal diversity and normal lung function.

OBJECTIVES We investigated the incidence of immediate hypersensitivity reaction (HSR) caused by different types of low-osmolar contrast media (LOCM) and cumulative exposure to LOCM. METHODS This cohort study included all consecutive patients who underwent LOCM-enhanced computed tomography from 2012 through 2014. We assessed 5 LOCM (iobitridol, iohexol, iomeprol, iopamidol, and iopromide). All patients were monitored for adverse events, and new symptoms and signs were recorded in real time using the Contrast Safety Monitoring and Management System (CoSM2oS). RESULTS The overall incidence of immediate HSR to LOCM was 0.97% (2004 events resulting from 205 726 exposures). Incidence differed significantly depending on whether the patient had a previous history of HSR to LOCM (0.80% in patients with no history and 16.99% in patients with a positive history of HSR to LOCM, P=.001). The incidence of HSR to individual LOCM ranged from 0.72% (iohexol) to 1.34% (iomeprol), although there were no significant differences across the 5 LOCM. A longitudinal analysis demonstrated that the incidence of HSR increased gradually with more frequent previous exposure to LOCM (HR=2.006 [95%CI, 1.517-2.653], P

Chronic cough is a common problem in various populations. The present study assessed the impact of cough and unmet needs in Korean patients with chronic cough. This cross-sectional multi-center study enrolled adult patients newly referred to clinic for assessment of chronic cough. A second group of patients with unexplained chronic cough following detailed assessment were recruited for comparison. Patients completed self-reported questionnaires, including cough characteristics, impact of cough on daily life, and unmet needs. A total of 447 subjects were recruited from six referral clinics, including 408 with chronic cough and 39 with unexplained chronic cough. Almost all patients reported that cough impacted their daily lives. Psychosocial impacts were more evident in unexplained cough patients compared to newly referred patients. Approximately 75% of newly referred patients had previously sought medical care for cough on multiple occasions, but the effectiveness of treatment was limited (70.3%) or absent (17.3%). The most frequent unmet need was the ineffectiveness of treatment (49.3%), followed by unclear diagnosis (30.1%). The majority of participants ( > 80%) expressed the need for further information on accessing cough specialists and disease management. The main problem faced by unexplained cough patients was poor cough control despite treatment (64%). Chronic cough has a substantial impact on daily life and is worst in those whose cough remains unexplained following assessment. Ineffectiveness of treatment and unclear diagnosis were major unmet needs. Medical information about chronic cough was also lacking. Improvements in the management of chronic cough patients in Korea are necessary.

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.

Patient education is important for successful management of atopic dermatitis; however, due to limited time and resources, patient education remains insufficient. This study aimed to investigate the current state of education provided by Korean dermatologists, pediatric allergists, and allergists to patients with atopic dermatitis. A questionnaire survey consisting of items regarding educational programs for patients with atopic dermatitis was conducted via e-mail. In total, 153 participants responded to the questionnaires, and 26.8% indicated that they have had separate educational programs. The workforce involved in the educational program included nurses, residents or fellows, dieticians, pharmacists, and clinical psychologists. Most education protocols addressed the characteristics and natural course of atopic dermatitis and environmental management. Overall, 96.7% of the participants replied that an additional charge is needed for education; moreover, additional assistance from an academic society or association, in the form of medical staff, organized data, and advertisement, is required to develop and provide a well-structured educational program. A standardized education protocol will effectively provide appropriate education for patients with atopic dermatitis. Arrangement of education fees, covered by the National Health Insurance Service, will lead to the establishment of a structured educational program and participation of an additional medical workforce.

It has been recently reported that cigarette smoke exposure during allergen sensitization facilitates the development of allergic asthma; however, the underlying mechanisms remain elusive. We evaluated the role of interleukin (IL-23) in a cigarette smoke extract (CSE)-induced Dermatophagoides pteronyssinus (Dp)-allergic asthma mouse model. BALB/c mice were exposed to CSE during allergen sensitization period. Anti-IL-23p19 or IL-23R antibody was administered during the sensitization period. And we evaluated several immunological responses. The expression of IL-23 and IL-23 receptor (IL-23R) was examined in lung tissue. IL-23 and IL-23R expression was increased in the airway epithelium of Dp/CSE co-administered mice. CSE administration during the sensitization promoted Dp-allergic sensitization and the development of asthma phenotypes. Additionally, the proportion of innate lymphoid type 2 cells (ILC2) was also increased by CSE and Dp co-instillation. Anti-IL-23 or IL-23R antibody treatment during allergen sensitization significantly diminished phenotypes of allergic asthma and the ILC2 population. The levels of IL-33 and thymic stromal lymphopoietin (TSLP) were also significantly reduced by anti-IL-23 or IL-23R antibody treatment. IL-23 may thus play a significant role in cigarette smoke-induced allergic sensitization and asthma development. Clinically, the increase in allergen sensitization due to cigarette exposure causes onset of asthma, and IL-23 may be important in this mechanism. KEY MESSAGES: IL-23 and IL-23R expression was increased in the lung epithelium of Dp and CSE co-exposed mice during sensitization period. The population of ILC2s was increased in Dp and CSE co-exposed mice during sensitization period. Anti-IL23 or IL-23R antibody treatment with co-administration of CSE and HDM during sensitization period significantly suppresses ILC2. In vitro, IL-23 blockade in Dp and CSE-stimulated epithelial cells suppressed IL-13 expression in ILC2.

While hypersensitivity reactions (HSR) to intravenously administered iodinated contrast media (ICM) have been well studied, not much is known about HSR to intra-arterially administered ICM.A prospective observational study was performed to evaluate coronary angiography (CAG)-induced ICM hypersensitivity in patients who underwent CAG using ICM including ioversol, a low-osmolar non-ionic monomer, and iodixanol, an iso-osmolar non-ionic dimer. The HSR were investigated through in-patient monitoring after CAG and telephone interview after discharge.A total of 714 patients were enrolled during the observation period, of whom 26 (3.6%) showed immediate HSR and 108 (15.1%) showed delayed HSR. With regard to severity, proportion of immediate HSR grades 1, 2, and 3 was 57.7%, 38.5%, and 3.8%, respectively, whereas that of delayed HSR grades 1, 2, and 3 was 85.2%, 13.9%, and 0.9%, respectively. Multivariate analysis revealed that previous intra-arterial exposure to ICM was an independent risk factor for immediate HSR (odds ratio (OR) 2.92, 95% confidence interval (CI) 1.22-6.96; p = 0.015). Iodixanol was a significant risk factor for delayed HSR (OR 1.61, 95% CI 1.07-2.43; p = 0.024) and correlated with a higher incidence of delayed HSR within 24-h post-ICM administration compared to ioversol.The incidence rate of immediate and delayed HSR in intra-arterially administered ICM was 3.6% and 15.1%, respectively. Previous exposure to intra-arterially administered contrast media was a significant risk factor for immediate HSR. Compared to ioversol, iodixanol was associated with relatively earlier and more frequent delayed HSR.• In this prospective study, the incidence of immediate and delayed hypersensitivity in intra-arterial injection of contrast media during coronary angiography was 3.6% and 15.1%, respectively. • Delayed hypersensitivity reactions were more common but less severe than immediate hypersensitivity reactions during coronary angiography. • Previous exposure to ICM via intra-arterial route was a significant risk factor for immediate hypersensitivity to intra-arterial contrast medium.

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.

While patients with nonalcoholic fatty liver disease (NAFLD) continue to increase worldwide, few hematological biomarkers are helpful. This study examined the potential of small dense low density lipoprotein (sdLDL) as a noninvasive biomarker for NAFLD and investigated the relevance of liver fibrosis. One hundred seventy two patients were enrolled: 121 NAFLD patients and 51 healthy controls. The lipoprotein profiles of NAFLD patients and controls were analyzed, and transient elastography (Fibroscan®) was performed to evaluate the degree of NAFLD. The liver biopsy results in some NAFLD patients were also analyzed. Age-gender matching was performed among the 172 patients, and a comparison with 46 NAFLD patients with the control group confirmed that the sdLDL (P .001) is significantly higher in the NAFLD group. A liver fibrosis test performed on 121 NAFLD patients confirmed a positive correlation between the degree of hepatic fibrosis and the sdLDL/LDL ratio (R = 0.215, P = .017). The area under the curve of the sdLDL for the diagnosis of NAFLD was 0.734 (95% CI, 0.631-0.838), and the area under the curve of the sdLDL/LDL ratio was 0.730 (95% CI, 0.621-0.829). The sdLDL and NAFLD activity scores of the 11 NAFLD patients who underwent liver biopsy showed a positive correlation, but it was not statistically significant. The sdLDL was higher in NAFLD patients than in controls and showed a tendency to increase gradually with increasing degree of hepatic steatosis and fibrosis. In particular, the sdLDL/LDL ratio showed a significant correlation with the degree of hepatic fibrosis, and the sdLDL measurement could be useful in NAFLD patients.

Background Transglutaminase 2 (TG2), a multifunctional calcium‐dependent acyltransferase, is upregulated in asthmatic airways and reported to play a role in the pathogenesis of allergic asthma. However, the underlying mechanism is not fully understood. Objective To investigate the role of TG2 in alternative activation of alveolar macrophages by using murine asthma model. Methods TG2 expression was assessed in induced sputum of 21 asthma patients and 19 healthy controls, and lung tissue of ovalbumin (OVA)‐induced murine asthma model. To evaluate the role of TG2 in asthma, we developed an OVA asthma model in both TG2 null and wild‐type mice. The expression of M2 macrophage markers was measured by fluorescence‐activated cell sorting (FACS) after OVA sensitization and challenge. To evaluate the effect of TG2 inhibition in vitro, interleukin 4 (IL‐4) or IL‐13‐stimulated expression of M2 macrophage markers was measured in CRL‐2456 cells in the presence and absence of a TG2 inhibitor. Results The expression of both TG2 and M2 markers was increased in the sputum of asthmatics compared with that of healthy controls. The expression of TG2 was increased in macrophages of OVA mice. Airway hyperresponsiveness, and the number of inflammatory cells, including eosinophils, was significantly reduced in TG2 null mice compared with wild‐type mice. Enhanced expression of M2 markers in OVA mice was normalized by TG2 knockout. IL‐4 or IL‐13‐stimulated expression of M2 markers in alveolar macrophages was also attenuated by TG2 inhibitor treatment in vitro. Conclusion Our results suggest that TG2‐mediated modulation of alveolar macrophage polarization plays important roles in the pathogenesis of asthma., Transglutaminase 2 (TG2) is crucial in the development of asthma by alternatively activating alveolar macrophage as well as augmentation of Th2 response. TG2 inhibitor directly suppresses Th2 cytokine‐driven alternative activation of alveolar macrophage.

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 aims 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 (HDM) and DEP. Changes in immune cell profiles caused by DEP exposure were confirmed by flow cytometry, RNA seq analysis. The roles of Sialic acid-binding, Ig-like lectin F (SiglecF)+ neutrophils were further evaluated by adoptive transfer experiment and in vitro functional studies. Results We show here that DEP exposure induces a unique population of lung granulocytes that co-express Ly-6G and sialic acid-binding, Ig-like lectin (Siglec)-F. These cells differ phenotypically, morphologically, functionally, and transcriptionally from other SiglecF-expressing cells in the lungs. Our findings with murine models suggest that intratracheal challenge with DEP induces the local release of adenosine 5'-​triphosphate (ATP), which is a damage-associated molecular pattern (DAMP) signal. ATP 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 in the patients with asthma-COPD overlap (ACO). Conclusion SiglecF+ neutrophil is a novel and critical player in airway inflammation and targeting the populations could reverse or ameliorate asthma.

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.We aimed to describe the characteristics of SEA and identify its patient subgroups.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.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.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.

Cough is a protective mechanism against aspiration, but it becomes pathologic when cough reflex is impaired or hypersensitive. Chronic cough is a clinical syndrome in adults, commonly characterized by hypersensitivity in the cough reflex, and is more prevalent and difficult to manage in older adults (≥65 years). The reason for the age-related increase in prevalence is unknown but may be related to comorbidities that are more frequent with aging. Adverse drug reactions can be also problematic in the aged patients, as they are prone to cognitive dysfunction, injurious fall, or pneumonia. In this chapter, we describe the characteristics of chronic cough in older adults and discuss clinical approaches including safety issues of therapeutic options.