Prescription patterns and effectiveness of medications for chronic obstructive pulmonary disease: A retrospective study of real-world settings.

This study aimed to define real-world prescription patterns in Korea and compare the effectiveness of chronic obstructive pulmonary disease (COPD) medications. We used national claims data provided by the Health Insurance Review and Assessment Service in Korea and examined patients who were first diagnosed with COPD and started treatment between May 1, 2017, and April 30, 2018, with no change in drug regimen. Among 30,784 patients with COPD, long-acting ß2 agonist (LABA) combined with long-acting muscarinic antagonist (LAMA) (32.7%), inhaled corticosteroid-LABA (ICS-LABA) (25.6%), LAMA (18.3%), ICS (5.8%), or LABA (4.6%) were prescribed as the first-choice inhalers. The use of LABA-LAMA (hazard ratio [HR], 0.248-0.584), LAMA (HR, 0.320-0.641), ICS-LABA (HR, 0.325-0.643), and xanthine (HR, 0.563-0.828) significantly reduced the total and severe exacerbation rates compared with no use of each medication. However, the use of ICS or LABA individually did not yield such effects. The continued use of LABA-LAMA, LAMA, and ICS-LABA showed a significant effect on exacerbation rate, whereas the long-term use of ICS, LABA, and xanthine did not. Moreover, some high doses of ICS-LABA did not show significant effects. This real-world study revealed that LAMA and/or LABA could be the first choice of therapy, as recommended by recent guidelines. However, ICS, xanthine, and high-dose ICS-LABA are still being prescribed frequently as first-line drugs in Korea.

AI in evaluating ambulation of stroke patients: severity classification with video and functional ambulation category scale.

BACKGROUND: The evaluation of gait function and severity classification of stroke patients are important to determine the rehabilitation goal and the level of exercise. Physicians often qualitatively evaluate patients' walking ability through visual gait analysis using naked eye, video images, or standardized assessment tools. Gait evaluation through observation relies on the doctor's empirical judgment, potentially introducing subjective opinions. Therefore, conducting research to establish a basis for more objective judgment is crucial. OBJECTIVE: To verify a deep learning model that classifies gait image data of stroke patients according to Functional Ambulation Category (FAC) scale. METHODS: Gait vision data from 203 stroke patients and 182 healthy individuals recruited from six medical institutions were collected to train a deep learning model for classifying gait severity in stroke patients. The recorded videos were processed using OpenPose. The dataset was randomly split into 80% for training and 20% for testing. RESULTS: The deep learning model attained a training accuracy of 0.981 and test accuracy of 0.903. Area Under the Curve(AUC) values of 0.93, 0.95, and 0.96 for discriminating among the mild, moderate, and severe stroke groups, respectively. CONCLUSION: This confirms the potential of utilizing human posture estimation based on vision data not only to develop gait parameter models but also to develop models to classify severity according to the FAC criteria used by physicians. To develop an AI-based severity classification model, a large amount and variety of data is necessary and data collected in non-standardized real environments, not in laboratories, can also be used meaningfully.

Guidelines for Manufacturing and Application of Organoids: Skin.

To address the limitations of animal testing, scientific research is increasingly focused on developing alternative testing methods. These alternative tests utilize cells or tissues derived from animals or humans for in vitro testing, as well as artificial tissues and organoids. In western countries, animal testing for cosmetics has been banned, leading to the adoption of artificial skin for toxicity evaluation, such as skin corrosion and irritation assessments. Standard guidelines for skin organoid technology becomes necessary to ensure consistent data and evaluation in replacing animal testing with in vitro methods. These guidelines encompass aspects such as cell sourcing, culture techniques, quality requirements and assessment, storage and preservation, and organoid-based assays.

Development of a multiplex droplet digital PCR method for detection and monitoring of Mycobacterium tuberculosis and drug-resistant tuberculosis.

BACKGROUND: The prevalence of multidrug-resistant tuberculosis (MDR-TB) among Korean tuberculosis patients is about 4.1%, which is higher than the OECD average of 2.6%. Inadequate drug use and poor patient compliance increase MDR-TB prevalence through selective pressure. Therefore, prompt detection of drug resistance in tuberculosis patients at the time of diagnosis and quantitative monitoring of these resistant strains during treatment are crucial. METHODS: A multiplex droplet digital PCR (ddPCR) assay was developed and assessed using DNA material of nine Mycobacterium tuberculosis strains with known mutation status that were purchased from the Korean National Tuberculosis Association. We collected a total of 18 MDR-TB residual samples referred for PCR analysis. Total DNA was extracted from the samples and subjected to the quadruplex ddPCR assay. Their results were compared to those of known resistance phenotypes. RESULTS: The analytical sensitivity and specificity of the multiplex ddPCR assay for detecting INH, RIF, EMB, FQ, and SM resistance-causing mutations ranged from 71.43 to 100% and 94.12-100%, respectively. Follow-up sample results showed that the quadruplex ddPCR assay was sensitive enough to detect IS6110 and other mutations even after onset of treatment. CONCLUSIONS: We developed a sensitive and accurate multiplex ddPCR assay that can detect the presence of tuberculosis quantitatively and resistance-conveying mutations concurrently. This tool could aid clinicians in the diagnosis and treatment monitoring of tuberculosis.

Angiotensin Receptor Blockers and the Risk of Suspected Drug-Induced Liver Injury: A Retrospective Cohort Study Using Electronic Health Record-Based Common Data Model in South Korea.

INTRODUCTION: Angiotensin receptor blockers are widely used antihypertensive drugs in South Korea. In 2021, the Korea Ministry of Food and Drug Safety acknowledged the need for national compensation for a drug-induced liver injury (DILI) after azilsartan use. However, little is known regarding the association between angiotensin receptor blockers and DILI. OBJECTIVE: We conducted a retrospective cohort study in incident users of angiotensin receptor blockers from a common data model database (1 January, 2017-31 December, 2021) to compare the risk of DILI among specific angiotensin receptor blockers against valsartan. METHODS: Patients were assigned to treatment groups at cohort entry based on prescribed angiotensin receptor blockers. Drug-induced liver injury was operationally defined using the International DILI Expert Working Group criteria. Cox regression analyses were conducted to derive hazard ratios and the inverse probability of treatment weighting method was applied. All analyses were performed using R. RESULTS: In total, 229,881 angiotensin receptor blocker users from 20 university hospitals were included. Crude DILI incidence ranged from 15.6 to 82.8 per 1000 person-years in treatment groups, most were cholestatic and of mild severity. Overall, the risk of DILI was significantly lower in olmesartan users than in valsartan users (hazard ratio: 0.73 [95% confidence interval 0.55-0.96]). In monotherapy patients, the risk was significantly higher in azilsartan users than in valsartan users (hazard ratio: 6.55 [95% confidence interval 5.28-8.12]). CONCLUSIONS: We found a significantly higher risk of suspected DILI in patients receiving azilsartan monotherapy compared with valsartan monotherapy. Our findings emphasize the utility of real-world evidence in advancing our understanding of adverse drug reactions in clinical practice.

Electric field simulation and appropriate electrode positioning for optimized transcranial direct current stimulation of stroke patients: an in Silico model.

Transcranial Direct Current Stimulation (tDCS) has benefits for motor rehabilitation in stroke patients, but its clinical application is limited due to inter-individual heterogeneous effects. Recently, optimized tDCS that considers individual brain structure has been proposed, but the utility thereof has not been studied in detail. We explored whether optimized tDCS provides unique electrode positions for each patient and creates a higher target electric field than the conventional approach. A comparative within-subject simulation study was conducted using data collected for a randomized controlled study evaluating the effect of optimized tDCS on upper extremity function in stroke patients. Using Neurophet tES LAB 3.0 software, individual brain models were created based on magnetic resonance images and tDCS simulations were performed for each of the conventional and optimized configurations. A comparison of electrode positions between conventional tDCS and optimized tDCS was quantified by calculation of Euclidean distances. A total of 21 stroke patients were studied. Optimized tDCS produced a higher electric field in the hand motor region than conventional tDCS, with an average improvement of 20% and a maximum of 52%. The electrode montage for optimized tDCS was unique to each patient and exhibited various configurations that differed from electrode placement of conventional tDCS. Optimized tDCS afforded a higher electric field in the target of a stroke patient compared to conventional tDCS, which was made possible by appropriately positioning the electrodes. Our findings may encourage further trials on optimized tDCS for motor rehabilitation after stroke.

Benefits of Robot-Assisted Upper-Limb Rehabilitation from the Subacute Stage after a Stroke of Varying Severity: A Multicenter Randomized Controlled Trial.

BACKGROUND: The aim of this study was to compare the clinical effectiveness of robot-assisted therapy with that of conventional occupational therapy according to the onset and severity of stroke. METHODS: In this multicenter randomized controlled trial, stroke patients were randomized (1:1) to receive robot-assisted therapy or conventional occupational therapy. The robot-assisted training group received 30 min of robot-assisted therapy twice and 30 min of conventional occupational therapy daily, while the conventional therapy group received 90 min of occupational therapy. Therapy was conducted 5 days/week for 4 weeks. The primary outcome was the Wolf Motor Function Test (WMFT) score after 4 and 8 weeks of therapy. RESULTS: Overall, 113 and 115 patients received robot-assisted and conventional therapy, respectively. The WMFT score after robot-assisted therapy was not significantly better than that after conventional therapy, but there were significant improvements in the Motricity Index (trunk) and the Fugl-Meyer Assessment. After robot-assisted therapy, wrist strength significantly improved in the subacute or moderate-severity group of stroke patients. CONCLUSIONS: Robot-assisted therapy improved the upper-limb functions and activities of daily living (ADL) performance as much as conventional occupational therapy. In particular, it showed signs of more therapeutic effectiveness in the subacute stage or moderate-severity group.

Roles of Inflammatory Biomarkers in Exhaled Breath Condensates in Respiratory Clinical Fields.

BACKGROUND: Exhaled condensates contain inflammatory biomarkers; however, their roles in the clinical field have been under-investigated. METHODS: We prospectively enrolled subjects admitted to pulmonology clinics. We collected exhaled breath condensates (EBC) and analysed the levels of six and 12 biomarkers using conventional and multiplex enzyme-linked immunosorbent assay, respectively. RESULTS: Among the 123 subjects, healthy controls constituted the largest group (81 participants; 65.9%), followed by the preserved ratio impaired spirometry group (21 patients; 17.1%) and the chronic obstructive pulmonary disease (COPD) group (21 patients; 17.1%). In COPD patients, platelet derived growth factor-AA exhibited strong positive correlations with COPD assessment test (ρ=0.5926, p=0.0423) and COPD-specific version of St. George's Respiratory Questionnaire (SGRQ-C) score (total, ρ=0.6725, p=0.0166; activity, ρ=0.7176, p=0.0086; and impacts, ρ=0.6151, p=0.0333). Granzyme B showed strong positive correlations with SGRQ-C score (symptoms, ρ=0.6078, p=0.0360; and impacts, ρ=0.6007, p=0.0389). Interleukin 6 exhibited a strong positive correlation with SGRQ-C score (activity, ρ=0.4671, p=0.0378). The absolute serum eosinophil and basophil counts showed positive correlations with pro-collagen I alpha 1 (ρ=0.6735, p=0.0164 and ρ=0.6295, p=0.0283, respectively). In healthy subjects, forced expiratory volume in 1 second (FEV1)/forced vital capacity demonstrated significant correlation with CC chemokine ligand 3 (CCL3)/macrophage inflammatory protein 1 alpha (ρ=0.3897 and p=0.0068). FEV1 exhibited significant correlation with CCL11/eotaxin (ρ=0.4445 and p=0.0017). CONCLUSION: Inflammatory biomarkers in EBC might be useful to predict quality of life concerning respiratory symptoms and serologic markers. Further studies are needed.

Inhibition of Dickkopf-1 enhances the anti-tumor efficacy of sorafenib via inhibition of the PI3K/Akt and Wnt/ß-catenin pathways in hepatocellular carcinoma.

BACKGROUND: Sorafenib improves the overall survival in patients with advanced hepatocellular carcinoma (HCC). Dickkopf-1 (DKK1) is commonly overexpressed in HCC. In this study, we investigated whether the inhibition of DKK1 enhances the anti-tumor efficacy of sorafenib in HCC. METHODS: HCC cells were treated with sorafenib and WAY-262611, which is an inhibitor of DKK1. Transgenic mouse models were also developed using hydrodynamic tail vein injection. Mice were orally administered with sorafenib (32 mg/kg), WAY-262611 (16 mg/kg), or sorafenib + WAY-262611 for 10 days. Mechanisms of sorafenib and WAY-262611 were explored via western blotting, immunostaining, and RNA sequencing. RESULTS: DKK1 was significantly overexpressed in patients with HCC than in the healthy controls and patients with liver diseases except HCC (all P < 0.05). Compared with sorafenib alone, sorafenib + WAY-262611 significantly inhibited the cell viability, invasion, migration, and colony formation by promoting apoptosis and altering the cell cycles in HCC cells (all P < 0.05). Moreover, sorafenib + WAY-262611 decreased the p110α, phospho-Akt (all P < 0.05), active ß-catenin (all P < 0.05) and phospho-GSK-3ß (Ser9) expression levels, while increasing the phospho-GSK-3ß (Tyr216) expression levels compared with those in the sorafenib alone in vitro and in vivo. In addition, sorafenib + WAY-262611 inhibited tumor progression by regulating cell proliferation and apoptosis, significantly better than sorafenib alone in mouse models. CONCLUSIONS: Our results indicate that DKK1 inhibition significantly enhances the anti-tumor efficacy of sorafenib by inhibiting the PI3K/Akt and Wnt/ß-catenin pathways via regulation of GSK3ß activity, suggesting a novel therapeutic strategy for HCC. Video Abstract.

Effects of chitinase-1 inhibitor in obesity-induced and -aggravated asthma in a murine model.

AIMS: Despite recent investigations on the role of chitinase in asthma, its role in obesity-induced asthma has not been evaluated. Therefore, we investigated the roles of chitin, chitinase-1, and a chitinase-1 inhibitor (compound X, CPX) in a murine model. MAIN METHODS: We assigned C57BL/6 mice to the ovalbumin (OVA) model or obesity model group. In the OVA model, mice received intraperitoneal OVA twice within a 2-week interval and intranasal OVA for 3 consecutive days. Additionally, chitin was intranasally administered for 3 consecutive days, and CPX was intraperitoneally injected three times over 5 days. In the obesity model, a high-fat diet (HFD) was maintained for 13 weeks, and CPX was intraperitoneally injected eight times over 4 weeks. KEY FINDINGS: In the OVA model, chitin aggravated OVA-induced airway hyper-responsiveness (AHR), increased bronchoalveolar lavage fluid (BALF) cell proliferation, increased fibrosis, and increased the levels of various inflammatory cytokines (including chitinase-1, TGF-ß, TNF-α, IL-1 ß, IL-6, IL-4, and IL-13). CPX treatment significantly ameliorated these effects. In the obesity model, HFD significantly increased AHR, BALF cell proliferation, fibrosis, and the levels of various inflammatory cytokines. Particularly, compared to the control group, the mRNA expression of chitinase, chitinase-like molecules, and other molecules associated with inflammation and the immune system was significantly upregulated in the HFD and HFD/OVA groups. Immunofluorescence analysis also showed increased chitinase-1 expression in these groups. CPX significantly ameliorated all these effects in this model. SIGNIFICANCE: This study showed that CPX can be an effective therapeutic agent in asthma, especially, obesity-induced and -aggravated asthma to protect against the progression to airway remodeling and fibrosis.

Long-Term Clinical Outcomes of Patients with Chronic Obstructive Pulmonary Disease with Sarcopenia.

BACKGROUND AND OBJECTIVE: Sarcopenia with muscle wasting and weakness is a common occurrence among patients with chronic obstructive pulmonary disease (COPD). We aimed to evaluate the clinical outcomes of sarcopenia in patients with COPD. METHODS: We reviewed the electronic medical records of 71 patients with COPD between 1 January 2012, and 31 December 2018. We longitudinally analyzed clinical outcomes in patients with COPD with and without sarcopenia. RESULTS: Compared to the non-sarcopenia group COPD, the sarcopenia group showed a higher rate of acute exacerbation events of COPD (AE COPD, 84.6% vs. 31.0%, p = 0.001), all-cause mortality (30.8% vs. 5.2%, p = 0.022), and pneumonia occurrence per year (median [first quartile-third quartile]; 0.2 [0.0-1.6] vs. 0.0 [0.0-0.2], p = 0.025). Sarcopenia was an independent risk factor for AE COPD in Cox regression analysis (hazard ratio, 5.982; 95% confidence interval, 1.576-22.704). Hand grip strength was associated with the COPD Assessment Test (CAT) score and annual Charlson's comorbidity index score change. Total skeletal muscle mass index (SMMI) was associated with the modified medical research council dyspnea scale score, CAT score, body mass index, airflow obstruction, dyspnea, and exercise (BODE) index, and alanine transaminase. Trunk SMMI was significantly associated with AE COPD, while appendicular SMMI was associated with BODE index and annual intensive care unit admissions for AE COPD. CONCLUSIONS: Sarcopenia is associated with clinical prognosis, pneumonia occurrence, and the acute exacerbation of COPD requiring intensive care in patients with COPD. Therefore, it is important to carefully monitor sarcopenia development as well as recommend appropriate exercise and nutritional supplementation in patients with COPD.

Low Skeletal Muscle Mass and Clinical Outcomes in Chronic Obstructive Pulmonary Disease.

BACKGROUND: In patients with chronic obstructive pulmonary disease (COPD), decreased muscle mass is a frequently encountered comorbidity in clinical practice. However, the evaluation of muscle mass in patients with COPD in real-world practice is rare. METHODS: We retrospectively reviewed the electronic medical records of all patients with COPD who underwent bioelectrical impedance analysis at least once between January 2011 and December 2021 in three hospitals. Then, we analyzed the performance rate of muscle mass measurement in the patients and the correlation between muscle mass, clinical parameters, and COPD prognosis. RESULTS: Among the 24,502 patients with COPD, only 270 (1.1%) underwent muscle mass measurements. The total skeletal muscle mass index was significantly correlated with albumin, alanine transaminase, and creatinine to cystatin C ratio in patients with COPD (r=0.1614, p=0.011; r=0.2112, p=0.001; and r=0.3671, p=0.001, respectively). Acute exacerbation of COPD (AE COPD) was significantly correlated with muscle mass, especially the truncal skeletal muscle mass index (TSMI) in males (r=-0.196, p=0.007). In the multivariate analysis, TSMI and cystatin C were significant risk factors for AE COPD (hazard ratio, 0.200 [95% confidence interval, CI, 0.048 to 0.838] and 4.990 [95% CI, 1.070 to 23.278], respectively). CONCLUSION: Low muscle mass negatively affects the clinical outcomes in patients with COPD. Despite its clinical significance, muscle mass measurement is performed in a small proportion of patients with COPD. Therefore, protocols and guidelines for the screening of sarcopenia in patients with COPD should be established.

Safety and therapeutic effects of personalized transcranial direct current stimulation based on electrical field simulation for prolonged disorders of consciousness: study protocol for a multi-center, double-blind, randomized controlled trial.

Background: Disorders of consciousness (DOC) resulting from acquired brain injury (ABI) increase the mortality rate of patients, complicate rehabilitation, and increase the physical and economic burden that DOC imposes on patients and their families. Thus, treatment to promote early awakening from DOC is vital. Transcranial direct current stimulation (tDCS) has shown great potential for promoting neuro-electrochemical activity. However, previous tDCS studies did not consider structural damage or head and brain lesions, so the applicability of the results to all DOC patients was limited. In this study, to establish a patient-specific tDCS treatment plan considering the brain lesions of and damage sustained by DOC patients, we considered the electric field calculated by a the "finite electric" three-dimensional brain model based on magnetic resonance images. This protocol was developed to aid tDCS treatment of actual patients, and to verify its safety and effectiveness. Methods/design: Twenty-four patients with DOC after ABI will be enrolled in this cross-over trial. All participants will receive typical rehabilitation combined with sham tDCS and typical rehabilitation plus personalized tDCS (P-tDCS). Each interventional period will last 2 weeks (30 min/day, 5 days/week). The primary outcome [score on the Korean version of the Coma Recovery Scale-Revised (K-CRS-R)] will be assessed at baseline and the end of the first day of the intervention. Secondary outcomes (K-CRS-R at 1 week and 2 weeks after experimental session and quantitative EEG changes quantitative electroencephalography changes) will be measured at baseline and the end of week 4. Adverse events will be recorded during each treatment session. Discussion: For patients with neurological disorders, tDCS has served as a painless, non-invasive, easily applied, and effective therapy for several decades, and there is some evidence that it can improve the level of consciousness of patients with DOC. However, variability in the effects on consciousness among subjects have been reported and personalized strategies are lacking. This protocol is for a randomized controlled trial designed to validate the effectiveness and safety of P-tDCS combined with typical rehabilitation for DOC. Clinical trial registration: https://cris.nih.go.kr, identifier KCT0007157.

Outstanding Characteristics of Birt-Hogg-Dube Syndrome in Korea.

Birt-Hogg-Dube (BHD) is a rare genetic disorder characterized by multiple lung cysts, typical skin manifestations, and renal tumors. We prospectively enrolled thirty-one subjects from four South Korean institutions with typical lung cysts, and next-generation sequencing was conducted. We prospectively enrolled thirty-one subjects from four Korean institutions with typical lung cysts. Next-generation sequencing was performed to investigate mutations in the following genes: FLCN, TSC1, TSC2, CFTR, EFEMP2, ELN, FBLN5, LTBP4, and SERPINA1. BHD was diagnosed in 11 of the 31 enrolled subjects (35.5%; FLCN mutations). Notably, we identified three novel mutations (c.1098G>A, c.139G>T, and c.1335del) that have not been previously reported. In addition to FLCN mutations, we also observed mutations in CFTR (16.1%), LTBP4 (9.7%), TSC2 (9.7%), TSC1 (3.2%), ELN (3.2%), and SERPINA1 (3.2%). According to a systematic review of 45 South Korean patients with BHD, the prevalence of pneumothorax (72.7%) was greater in South Korea than in the rest of the world (50.9%; p = 0.003). The prevalence of skin manifestations (13.6%) and renal tumors (9.1%) was lower in Korea than in the rest of the world, at 47.9% [p < 0.001] and 22.5% [p = 0.027], respectively). This study confirmed a significant prediction model for BHD based on age, number of lung cysts (>40), and maximal diameter of lung cysts (>2 cm) regardless of skin manifestations and renal tumors. Importantly, three novel mutations (c.1098G>A, c.139G>T, and c.1335del) were identified. In conclusion, South Korean patients with BHD display characteristics that are different from those observed in patients of other nationalities. Detailed characterization of lung cysts is needed to define BHD, especially in South Korea, even if patients do not present with skin or renal lesions.

Airflow obstruction and chronic obstructive pulmonary disease are common in pulmonary tuberculosis even without sequelae findings on chest X-ray.

PURPOSE: Pulmonary tuberculosis (TB) is a well-known risk factor for airflow obstruction and chronic obstructive pulmonary disease (COPD). The prognosis of TB without sequelae on chest X-ray (CXR) remains uncertain. METHODS: We used the 2008-2009 Korea National Health and Nutrition Examination Survey (KNHANES) data and 2007-2012 KNHANES-matched Health Insurance Review and Assessment Service cohort data. Airflow obstruction was assessed using a pulmonary function test. COPD was defined using diagnostic codes and the use of COPD medication for 3-year. We classified subjects into three groups based on TB history and sequelae on CXR. RESULTS: In 4911 subjects, the CXR(-) (no TB sequelae on CXR) post-TB group (n = 134) showed similar characteristics and normal lung function compared to that of the control group (n = 4,405), while the CXR(+) (TB sequelae on CXR) post-TB group (n = 372) showed different characteristics and reduced lung function. The prevalence of airflow obstruction was 9.3%, 13.4%, and 26.6% in control, CXR(-) post-TB, and CXR(+) post-TB groups, respectively. COPD was more common in the post-TB with CXR(+) (6.5%) or without CXR (-) (4.5%) groups, than in the control group (1.8%). Compared to the CXR(-) post-TB group, the control group showed a lower risk for airflow obstruction (OR, 0.774; p = .008). The CXR(+) post-TB group showed a higher risk for airflow obstruction (OR, 1.456; p = .011). The Control group also showed a lower risk for the development of COPD than the CXR(-) post-TB group (OR, 0.496; p = .011). CONCLUSIONS: We need to educate TB patients that airway obstruction and COPD can easily develop, even if TB sequelae are not observed on CXR.

Next-generation sequencing analysis of hepatitis C virus resistance-associated substitutions in direct-acting antiviral failure in South Korea.

BACKGROUND/AIMS: We used next-generation sequencing (NGS) to analyze resistance-associated substitutions (RASs) and retreatment outcomes in patients with chronic hepatitis C virus (HCV) infection who failed direct-acting antiviral agent (DAA) treatment in South Korea. METHODS: Using prospectively collected data from the Korean HCV cohort study, we recruited 36 patients who failed DAA treatment in 10 centers between 2007 and 2020; 29 blood samples were available from 24 patients. RASs were analyzed using NGS. RESULTS: RASs were analyzed for 13 patients with genotype 1b, 10 with genotype 2, and one with genotype 3a. The unsuccessful DAA regimens were daclatasvir+asunaprevir (n=11), sofosbuvir+ribavirin (n=9), ledipasvir/sofosbuvir (n=3), and glecaprevir/pibrentasvir (n=1). In the patients with genotype 1b, NS3, NS5A, and NS5B RASs were detected in eight, seven, and seven of 10 patients at baseline and in four, six, and two of six patients after DAA failure, respectively. Among the 10 patients with genotype 2, the only baseline RAS was NS3 Y56F, which was detected in one patient. NS5A F28C was detected after DAA failure in a patient with genotype 2 infection who was erroneously treated with daclatasvir+asunaprevir. After retreatment, 16 patients had a 100% sustained virological response rate. CONCLUSION: NS3 and NS5A RASs were commonly present at baseline, and there was an increasing trend of NS5A RASs after failed DAA treatment in genotype 1b. However, RASs were rarely present in patients with genotype 2 who were treated with sofosbuvir+ribavirin. Despite baseline or treatment-emergent RASs, retreatment with pan-genotypic DAA was highly successful in Korea, so we encourage active retreatment after unsuccessful DAA treatment.

Particulate matter10-induced airway inflammation and fibrosis can be regulated by chitinase-1 suppression.

BACKGROUND: Particulate matter10 (PM10) can induce airway inflammation and fibrosis. Recently, chitinase-1 has been shown to play key roles in inflammation and fibrosis. We aimed to investigate the effects of chitinase-1 inhibitor in PM10-treated murine mice models. METHODS: In female BALB/c mice, PM10 was intranasally administered six times over 3 weeks, and ovalbumin (OVA) was intraperitoneally injected and then intranasally administered. Chitinase-1 inhibitor (CPX) 6 times over 3 weeks or dexamethasone 3 times in the last week were intraperitoneally administered. Two days after the last challenges, mice were euthanized. Messenger RNA sequencing using lung homogenates was conducted to evaluate signaling pathways. RESULTS: PM10 and/or OVA-induced airway inflammation and fibrosis murine models were established. CPX and dexamethasone ameliorated PM10 or PM10/OVA-induced airway hyper-responsiveness, airway inflammation, and fibrosis. CPX and dexamethasone also reduced levels of various inflammatory markers in lung homogenates. PM10 and OVA also induced changes in mRNA expression across an extreme range of genes. CPX and dexamethasone decreased levels of mRNA expression especially associated with inflammation and immune regulation. They also significantly regulated asthma and asthma-related pathways, including the JACK-STAT signaling pathway. CONCLUSIONS: Chitinase-1 suppression by CPX can regulate PM10- and OVA-induced and aggravated airway inflammation and fibrosis via an asthma-related signaling pathway.

Asthma and increased risk of myocardial infarction and mortality among hypertensive Korean patients.

This study aimed to evaluate the effects of asthma on cardiovascular disease incidence in patients with hypertension. A total of 639,784 patients with hypertension from the Korea National Health Insurance Service database were included, of whom 62,517 had history of asthma after propensity score matching. The risks of all-cause mortality, myocardial infarction (MI), stroke, and end-stage renal disease (ESRD) were assessed according to the presence of asthma, long-acting ß2-agonist (LABA) inhaler usage, and/or systemic corticosteroid usage for up to 11 years. In addition, whether these risks were modified by average blood pressure (BP) levels during the follow-up period was examined. Asthma was associated with an increased risk of all-cause mortality (hazard ratio [HR], 1.203; 95% confidence interval [CI], 1.165-1.241) and MI (HR, 1.244; 95% CI, 1.182-1.310) but not the risk of stroke or ESRD. LABA inhaler usage was associated with a higher risk of all-cause mortality and MI, and systemic corticosteroids usage showed a higher risk of ESRD as well as all-cause mortality and MI among hypertensive patients with asthma. Compared to patients without asthma, there was a graded increase in the risk of all-cause mortality and MI in those with asthma without LABA inhaler/systemic corticosteroid usage and in those with asthma with LABA inhaler/systemic corticosteroid usage. These associations were not significantly modified by BP levels. This nationwide population-based study supports that asthma may be a clinical factor that increases the risk of poor outcomes in patients with hypertension.

Association between Serum Levels of Interleukin-25/Thymic Stromal Lymphopoietin and the Risk of Exacerbation of Chronic Obstructive Pulmonary Disease.

Th2 inflammation is associated with various characteristics of patients with chronic obstructive pulmonary disease (COPD). In this study, we analyzed the COPD exacerbation risk associated with serum levels of interleukin (IL)-25/thymic stromal lymphopoietin (TSLP) and eosinophils. We studied the KOCOSS cohort, a multicenter COPD cohort created by 54 medical centers in South Korea. We extracted data collected between April 2012 and August 2020. We measured serum levels of TSLP and IL-25 in those who agreed to provide blood, and assessed exacerbation risk according to each. In all, 562 patients were enrolled. The IL-25-high group had a lower St. George's Respiratory Questionnaire score than others, and the TSLP-high group had a poorer exercise capacity than the TSLP-low group. There were no significant differences in the forced expiratory volume in 1 s (FEV1), the levels of Th2 inflammatory biomarkers, or the exacerbation histories between the two groups. The 3-year decline in FEV1 was not significantly affected by IL-25 or TSLP levels. In terms of 1-year exacerbation risk, individuals in the IL-25-high group were at lower risk for moderate-to-severe exacerbation than others. A high TSLP level was associated with a lower risk of severe exacerbation but only in the eosinophil-low group. Serum levels of IL-25 are negatively correlated with moderate-to-severe exacerbation risk in this cohort. A negative correlation between severe exacerbation risk and TSLP level was apparent only in the eosinophil-low group.