Asthmatic Patients Research Articles

Altered static and dynamic functional network connectivity and combined Machine learning in asthma.

Altered static and dynamic functional network connectivity and combined Machine learning in asthma.

Personal exposure to particulate matter oxidative potential and airway inflammation: differences between asthmatic and non-asthmatic adults.

Personal exposure to particulate matter oxidative potential and airway inflammation: differences between asthmatic and non-asthmatic adults.

Identification and validation of PARK7 as a novel mitochondria-related signature associated with immune microenvironment in asthma.

Identification and validation of PARK7 as a novel mitochondria-related signature associated with immune microenvironment in asthma.

METTL14-mediated lncRNA NEAT1 promotes asthma progression by regulating the miR-302a-3p/March5 axis.

METTL14-mediated lncRNA NEAT1 promotes asthma progression by regulating the miR-302a-3p/March5 axis.

A lifestyle educational course as an adjunct to biologic administration in patients with severe asthma: A feasibility study.

A lifestyle educational course as an adjunct to biologic administration in patients with severe asthma: A feasibility study.

Multi-trait genetic analysis of asthma and eosinophils uncovers pleiotropic loci in East Asians

Asthma is a prevalent respiratory condition with over 100 genetic loci identified through genome-wide association studies (GWAS). However, the genetic basis of asthma in East Asians remains underexplored. To address this, we performed a comprehensive analysis of shared genetic mechanisms between asthma and white blood cell (WBC) traits in East Asians, aiming to identify potential pleiotropic loci. Using linkage disequilibrium score regression (LDSC), we identified a significant genetic correlation between asthma and eosinophil count, further supported by Mendelian randomization (MR) analysis. A multi-trait analysis of GWAS (MTAG) uncovered 52 genome-wide significant loci, including 31 previously unreported loci specific to East Asians. Notably, we discovered a missense variant (rs75326924) in the CD36 gene that exhibits increased expression in lymphocytes and type 2 innate lymphoid cell (ILC2)-enriched cells in asthma patients, confirmed by flow cytometry. Proteomic profiling demonstrated downregulation of immune-related proteins such as Interleukin-7, Oncostatin M, and VEGFA in carriers of rs75326924, a variant previously associated with CD36 deficiency. Our findings provide insights into genetic loci and candidate genes underlying asthma in East Asians, offering potential targets for therapeutic interventions tailored to this population.

Altered levels of angiogenin and tRNA-derived fragments associate with severe asthma

Recent discoveries highlight angiogenin (ANG) and 5’ tRNA-derived fragments as key factors in stress response and cell survival. To explore their role in asthma pathogenesis, particularly in severe cases, we evaluated the levels of ANG and 5’ tRNA halves (tRHs) derived from tRNA Glu (5'-tRH Glu: tRF-32-87R8WP9N1EWJM) and tRNA Gly (5’-tRH Gly: tRF-30-PNR8YP9LON4V), two abundant tRHs in the respiratory tract, in sputum and blood samples from asthmatic patients. We found ANG expression is significantly increased in circulating leukocytes from severe asthma patients but not in sputum infiltrates. On the contrary, tRHs levels showed significant alterations only in extracellular compartments. Both tRHs were downregulated in the plasma of asthmatic patients, while elevated 5’-tRH Gly levels were observed in severe sputum samples, indicating tissue-specific roles in disease pathology. Additionally, tRH expression in leukocytes was negatively associated with the disrupted corticosteroid response in asthmatic patients. Altered levels of ANG and 5’-tRH Glu and 5’-tRH Gly were further validated in an in vitro model of pollutant-aggravated, allergen-stimulated macrophages. In summary, our findings provide new insights into the role of ANG and tRHs in asthma pathogenesis, highlighting their potential as novel markers for asthma phenotyping.

Impact of ERS/ATS 2022 bronchodilator response guidelines in asthma control

The aim of this study was to determine whether the BDR according to the new cut-off values is associated with worse asthma control compared with the 2005 definition. We conducted a prospective study on moderate to severe asthma patients under clinical follow-up. Patients were classified based on the BDR using both ERS/ATS 2022 and 2005 thresholds. We collected clinical and functional data, along with exacerbations over a one-year follow-up period. Among the 198 patients included, mean age was 60.2 years-old (SD 16.3), with 74.7% being women and 69.7% having severe asthma. According to the 2005 threshold, 46 (23.2%) showed bronchodilator responsiveness, whereas with the 2022 recommendations decreased to 38 (19.2%). The agreement between the 2005 and 2022 ERS/ATS criteria for BDR positivity was 92.17%, with a Cohen’s kappa coefficient of 0.76 (p < 0.001). Using the 2022 cut-off values, patients with BDR had a significantly lower mean asthma control test (ACT) score (19.9 vs 22.5; p = 0.001), while no difference was observed with the 2005 criteria. The relative risk of exacerbations after 1 year follow-up was 1.23 (CI 95% 1-1.25) with the 2022 recommendations, compared to 1.09 (CI 95% 0.88- 1.38) with the 2005 criteria. The use of the new BDR criteria could provide a valuable marker of asthma control, allowing for better risk stratification and more informed therapeutic decisions.

Asthma care bundle and pathway to improve asthma management in a community paediatric inpatient unit, a quality improvement initiative

Abstract Background Asthma is the most common chronic paediatric condition and a frequent cause of emergency department visits and hospitalizations. Objectives The project objective was to decrease inpatient length of stay (LOS) for asthma exacerbations between May 2021 and 2022. Methods The Institute for Healthcare Improvement Model for improvement was employed to study if systemic changes to asthma management could reduce hospital LOS. The inpatient asthma care bundle consisted of a discharge checklist, standardized care pathway that allowed nurse titration of bronchodilator based on an objective scoring tool and standardized team education. Results The pre-intervention mean inpatient LOS was 56 h, 100 h for patients with a Paediatric Intensive Care Unit (PICU) stay, and 52 h for patients without a PICU stay. While the mean PICU LOS remained unchanged, the mean LOS for patients without PICU stay decreased to 34 h and was sustained through the project’s completion. The percentage of healthcare professionals feeling “comfortable”/’very comfortable’ caring for asthmatic patients remained unchanged during the project (100%). Caregivers’ confidence regarding asthma management mean score increased from 6/10 to 9/10 after hospital discharge. No statistical increase respiratory-based emergency department presentation within 10 days of discharge, use of high-flow ventilation and transfer to PICU was noted. Conclusions Implementing an inpatient asthma care bundle reduced the mean LOS for patients without PICU stay from 52 to 34 h, which represents a 35% decrease. The most impactful intervention was the implementation of the inpatient asthma management pathway.

Targeted Knockdown of Epithelial Estrogen Receptor α to Mitigate Ferroptosis and Epithelial-Mesenchymal Transition in Eosinophilic Asthma.

Estrogen receptor α (ERα) is involved with the hyperresponsiveness and airway remodeling in asthma, but developing therapies targeting ERα remains challenging due to its multifaceted roles in different cell types and the poor efficacy of systemic ERα intervention in asthma. Previously, we uncovered the association of increased ERα expression in airway epithelial cells with poor pulmonary function and epithelial-mesenchymal transition (EMT) in asthma patients. This study further investigated the association of ERα expression with the ferroptosis and EMT levels in a cohort of eosinophilic asthma (EA) patients as well as in an eosinophil-epithelial coculture cell model. By loading small interfering RNA (siRNA) into a mesoporous silica nanoparticle (MSN) and then coating the extracted bronchial epithelial cytomembrane (CM), a bronchial epithelial CM home-targeting nanoplatform (siRNA@MSN@CM) was constructed to selectively decrease the ERα expression in bronchial epithelial cells. The targeting effect of bronchial epithelial cells was confirmed in vitro and in vivo, demonstrating the successful targeted knockdown of ERα expression. Silencing ERα in epithelial cells effectively prevented ferroptosis and EMT induced by coculturing with ferroptotic eosinophils. Targeted intervention of epithelium ERα with intratracheal delivery of siRNA(ERα)@MSN@CM nanoparticle significantly reduced the levels of ferroptosis in bronchial epithelial cells, airway inflammation, and airway remodeling in asthmatic mouse models. This study introduces an innovative nanomaterial for targeted drug delivery to epithelial cells and underscores the potential of targeted knockdown ERα in bronchial epithelial cells as a therapeutic strategy for asthma treatment.

Evaluation of Safety and Efficacy of Nebulizer Delivering Drugs in Lung Disease Patient: A Prospective Cohort Study

Respiratory disease, including asthma and Chronic Obstructive Pulmonary Disease (COPD), presents significant challenges in patient management and quality of life. Nebulizers are commonly used to deliver inhaled medications directly to the lungs, offering advantages for patients who struggle with traditional inhalers. However, the safety and efficacy of nebulizer treatments require thorough evaluation. This prospective cohort study aims to assess patient-reported outcomes, adherence to treatment regimens, and any adverse effects associated with nebulizer use. By analyzing these factors, the research seeks to inform clinical practices, enhance patient education, and develop guidelines to optimize the use of nebulizers in lung disease management. The study is on prospective observational cohort study was carried at a tertiary care hospital in erode, focusing on the nebulizer use patients for lung disease over a period of 9 months; the estimated sample size is 157 in were 22 patients were not involved in follow-up data were collected based on the questionnaires. The questioner is in 3section disease based, efficacy of drug and safety maintenance. In my study out of 157 patients, a male patient is highly affected by the respiratory disease. In hospital, 68% of the patient used the continuous nebulization. Albuterol drug is effective for asthma patients and combination of ipratropium bromide and levosalbutamol is effective in cod patients. Continuous nebulizer therapy in optimizing outcomes for respiratory patients and highlight the need for ongoing support to ensure patient comfort and satisfaction. My finding the use of albuterol for asthma and the combination of ipratropium bromide and levosalbutamol for COPD highlight the importance of proper medication use in enhancing clinical outcomes.

Association of IL4 (Rs2243250) Gene Variant and Mycoplasma Pneumoniae Infection with Asthma Susceptibility in an Iraqi Population.

Asthma is a multifactorial disease influenced by both genetic and environmental factors. This study aimed to investigate the association between the IL4 gene polymorphism (rs2243250) and asthma susceptibility, along with serum IL-4 levels. Additionally, it explored Mycoplasma pneumoniae infection as a potential risk factor for asthma. A total of 118 individuals were enrolled, including 60 asthma patients and 58 healthy controls. Genotyping for IL4 rs2243250 was performed using allele-specific PCR (AS-PCR). Previous Mycoplasma pneumoniae infection was assessed serologically, and serum IL-4 levels were measured using ELISA. No significant differences were observed between groups in terms of age, sex, or residence. Smoking (OR: 7.85, P = 0.001) and family history of asthma (OR: 5.33, P = 0.004) were identified as significant risk factors. Mycoplasma pneumoniae infection was significantly more prevalent in asthma patients (41.7%) than in controls, with a strong association with asthma risk (OR: 8.75, P < 0.0001). Genotype frequencies of rs2243250 differed significantly: CC (36.7% vs. 68.9%), CT (41.7% vs. 24.2%), and TT (21.6% vs. 6.9%) in patients versus controls, respectively. The T allele was more frequent among patients (42.5%) than controls (18.97%), increasing asthma risk (OR: 3.16, P = 0.0001). Both CT (OR: 3.25) and TT (OR: 5.91) genotypes were strongly associated with asthma. Moreover, individuals with the TT genotype had significantly higher serum IL-4 levels (P < 0.001). The IL4 rs2243250 polymorphism is associated with increased asthma susceptibility and elevated serum IL-4 levels in the Iraqi population. Mycoplasma pneumoniae infection also appears to be a significant contributing factor. Larger-scale studies are warranted to confirm these findings and further explore the role of this infection in asthma pathogenesis.

Predicting clinical exacerbations using respiratory oscillometry during home telemonitoring of patients taking medium/high dose asthma treatment

RationaleStrategies for asthma management need better tools to identify risk of exacerbations. In this prospective observational study, we investigated the utility of day-to-day variability in lung mechanics, measured by home telemonitored oscillometry, by examining relationships between current symptom control and future risk of exacerbation in asthma patients taking medium/high dose treatment, regardless of their level of asthma control.MethodsParticipants underwent ≥24 weeks of telemonitoring during stable or stepped-down treatment, with once-daily self-recording of symptoms, and oscillometry (Resmon Pro Diary, Restech srl, Milan, Italy). The Asthma Control Questionnaire (ACQ5) and exacerbations were capturedviaweekly telephone calls. Mean inspiratory resistance and reactance at 5 Hz (Rinspand Xinsp), and theirsdand coefficient of variation (CV) over 7-day windows, were calculated; their associations with current symptom control were examined using linear mixed modelling, and their predictive capacity for exacerbations in the following week using logistic regression and receiver-operator characteristic (ROC) analysis, and conditional probability methods.ResultsData from 30 participants were analysed (19 female; mean±sdage 59±13 years, BMI 30.1±6.6, %predFEV1 73.7±25.0), with mean monitoring adherence of 83.9±13.1%, with 16 exacerbations recorded from 12 participants. Only Xinspwas a significant predictor of current symptom control (p&lt;0.001). CVRinspprovided the highest accuracy for predicting future exacerbations (area under the ROC curve, AUC=0.664, p&lt;0.001); accuracy was further enhanced using individual conditional probability (AUC=0.836, p&lt;0.001).ConclusionThis proof-of-concept study shows that daily telemonitoring of oscillometry is useful for assessing current symptom control and future risk of exacerbations in asthma patients taking medium/high dose treatment.

Home spirometry telemonitoring in pediatric patients with asthma: a mixed study.

To evaluate the feasibility and practicality of home spirometry telemonitoring for pediatric patients with asthma, including both motivators and barriers, as well as the requirements for effective implementation. This single-arm, prospective study involved three phases: outpatient spirometry examination, home spirometry telemonitoring, and semi-structured interviews. A total of 110 children aged 5-12 years, who required spirometry monitoring at the pediatric outpatient clinic of the Second Affiliated Hospital of Chongqing Medical University, were enrolled. The PF286 (referred to as PF286), a home spirometry telemonitoring device was used for this study. Upon enrollment, each child initially underwent spirometry with a clinical-grade spirometer (Jaeger). Subsequently, they were tested using the PF286 under both supervised and unsupervised settings. To assess the consistency between PF286 and the clinical spirometer, we employed Pearson correlation coefficients. Children diagnosed with mild-to-moderate asthma, based on specified tests, participated in a four-week home spirometry telemonitoring program. After the telemonitoring period, semi-structured interviews were conducted with children, their guardians, and healthcare professionals to evaluate their experiences and identify the motivators and barriers in integrating home spirometry telemonitoring into clinical care. Spirometry data were collected using the PF286. The findings suggest that the PF286 is suitable for home spirometry telemonitoring in children, with unsupervised use yielding reliable data for clinical application. Semi-structured interviews with eight groups of children and their guardians, five nurses, and four physicians identified five key themes: "benefits of telemonitoring", "data accuracy and reliability", "barriers", "emotions", and " expectations". The study concludes that home spirometry telemonitoring is feasible and acceptable for pediatric asthma management. However, several challenges, such as cost, insurance coverage, data security, health education, and healthcare workload, need to be addressed prior to its widespread implementation. Future research should focus on leveraging artificial intelligence for early disease detection, treatment guidance, and improving the quality of life for pediatric asthma patients.

IoT-Enabled Smart Inhaler with GSM and Cloud-Based Health Monitoring System

Abstract- Asthma is a chronic respiratory condition that affects millions of individuals worldwide and often leads to serious health complications due to missed medication and exposure to environmental triggers. To address this issue, this paper presents the design and development of an IoT-based Smart Inhaler System aimed at improving medication adherence, monitoring environmental conditions, and enabling real-time alerts during critical situations. The system comprises a smart inhaler unit embedded with a usage detection sensor and a wearable smart band equipped with temperature, humidity, and gas sensors to detect potentially harmful surroundings. The collected data is transmitted to a cloud platform via Wi-Fi, while a GSM module provides emergency communication through SMS alerts. This comprehensive solution ensures proactive asthma care by integrating real-time monitoring, data logging, and timely intervention. The implementation demonstrates improved safety, reduced risks, and enhanced healthcare support for asthma patients through a cost-effective and intelligent system. Keywords— Asthma, Smart Inhaler, IoT, Environmental Monitoring, GSM, ESP8266 Node MCU, ThingSpeak, MQTT, Real-Time Alerting

SERPINB10 promotes macrophage M2 polarization and airway inflammation in asthma

BackgroundMacrophage M2 polarization plays a critical role in type 2 airway inflammation in asthma. We previously reported that serine peptidase inhibitor, clade B, member 10 (SERPINB10) promotes airway eosinophilic inflammation in asthma.ObjectiveTo investigate the role of SERPINB10 in macrophage M2 polarization and airway inflammation in asthma.MethodsThe expression of SERPINB10 was detected in bronchoalveolar lavage (BAL) cells from 15 control subjects and 36 asthma patients. Serpinb10 knockout mice and wild type mice were sensitized and challenged with ovalbumin (OVA). Macrophage polarization and airway inflammation were evaluated. An adoptive transfer experiment of Serpinb10-deficient macrophages to macrophage-depleted mice was performed to assess the effect of Serpinb10 deficiency in macrophages on the airway inflammation in the model. The role of SERPINB10 in the activation of IL-4 receptor (IL-4R) signaling pathway and macrophage M2 polarization was investigated in cell cultures.ResultsSERPINB10 expression was markedly elevated in BAL cells from asthmatic patients, and was significantly correlated with fractional exhaled nitric oxide and CD206, a marker for macrophage M2 polarization. In the OVA-induced allergic airway inflammation mouse model, Serpinb10 deficiency significantly inhibited airway inflammation, mucous cell metaplasia and airway hyperresponsiveness. Moreover, Serpinb10 deficiency suppressed the expression of M2 markers including Cd206, Arg1 in mouse lung tissues and the protein levels of M2 macrophage effector cytokines including Ccl17 and Ccl22 in BAL fluid. Adoptive transfer of Serpinb10-deficient bone marrow-derived macrophages (BMDMs) to wild type mice depleted macrophages significantly suppressed the airway inflammation and mucous cell metaplasia. Mechanistically, SERPINB10 suppresses the degradation of IL-4Rα in macrophages, thereby upregulating the phosphorylation of Stat6 and Akt and leading to macrophage M2 polarization.ConclusionsSERPINB10 promotes macrophage M2 polarization by suppressing IL-4Rα degradation and upregulating IL-4R signaling. SERPINB10 is a potential therapeutic target for asthma.

Bronchial Thermoplasty in the Treatment of Asthma A Literature Review

Introduction and purpose Asthma is a chronic inflammatory disorder affecting people worldwide. Although standard pharmacological management is adequate for most asthma patients, bronchial thermoplasty may serve as a therapeutic alternative in individuals with severe, uncontrolled asthma. The aim of this review is to summarize the knowledge of the effects of bronchial thermoplasty on symptom control, quality of life, and airway remodeling, as well as the use and effectiveness of this procedure in treating asthma. Description of the state of knowledge Bronchial thermoplasty (BT) is an endoscopic treatment method that can be used in patients with severe asthma, whose condition has not been adequately controlled with recommended pharmacological treatment. This procedure involves the application of radiofrequency energy to modify the airways’ structure and decrease airway smooth muscle mass. It is regarded as a safe and effective treatment option for long-term asthma management. Conclusion After bronchial thermoplasty, improved symptom control and a reduction in the frequency of exacerbations were observed, resulting from a decrease in airway smooth muscle mass and an expansion of airway volume. However, this therapeutic strategy is recommended for individuals for whom other treatments have proven ineffective.

COMPAC: COMputable Phenotype for Asthma in Children.

Background Pediatric asthma is one of the most common chronic diseases of childhood. Reliable identification of pediatric asthma patients in electronic health records (EHRs) is essential for both research and clinical care. However, existing computable phenotypes (CPs) exhibit varying effectiveness. This study aims to evaluate current CPs and develop a new CP, named COMPAC (COMputable Phenotype for Asthma in Children), to improve EHR-based identification of pediatric asthma patients. Methods Multiple CP rules were designed using various combinations of diagnosis codes, prescriptions, and clinical note text. A cohort from the University of Florida Integrated Data Repository (IDR) was used for validation through manual chart reviews. Performance was assessed using standard metrics and compared to existing CPs. Additionally, bootstrapping and demographic subgroup analyses were conducted to compare the performance of the new COMPAC to previously published CPs. Results COMPAC demonstrated improved case identification compared to existing CPs, with high sensitivity (0.728; 95% confidence interval [CI]: 0.607-0.864), positive predictive value (0.886; 95% CI: 0.737-1.0), and an overall F1 score of 0.797 (95% CI: 0.682-0.90). Notably, COMPAC outperformed two previously published CPs in terms of F1 score. Performance varied across demographic subgroups, with COMPAC showing the best results in males, non-Hispanic Whites, and the 6-12 year-old age group, though its performance was lower in the 2-5 year-old age range. Conclusion COMPAC offers an improved approach for pediatric asthma case identification in EHRs. However, further validation across different sites and refinement to capture a broader range of clinical presentations are necessary to optimize its sensitivity and specificity.

Seasonal variation of pediatric asthma exacerbations and its association with asthma phenotypes.

The objective of this study was to examine the associations of blood inflammatory phenotypes with acute pediatric asthma exacerbations during different seasons and the COVID-19 pandemic. A retrospective study was conducted involving 32,160 pediatric asthma patients from January 2008 to December 2021. Asthma blood inflammatory phenotypes were categorized based on low (L) and high (H) eosinophils (E) and neutrophils (N) (LBE/HBE: ≥ 0.25 × 109/L and LBN/HBN: ≥ 5 × 109/L, respectively) and logistic regression was used to examine the odds ratio (OR) of outcome variables. A 109/L increase of neutrophils and eosinophils was associated with a 1.015-fold (95% CI: 1.009-1.021) and a 1.057-fold increase in the OR (95% CI: 1.026-1.088) for asthma exacerbations of hospitalized pediatric asthma patients. An increase in HBE/LBN phenotype was associated with a respective 1.232-fold (95% CI: 1.081-1.404) and 1.248-fold (95% CI: 1.101-1.414) increase in the OR for asthma exacerbations of hospitalized pediatric asthma patients before the COVID-19 pandemic in the winter and autumn seasons. However, an increase of LBE/LBN phenotype was associated with a respective 0.873-fold (95% CI: 0.769-0.991), 0.872-fold (95% CI: 0.771-0.986), and 0.813-fold (95% CI: 0.709-0.932) decrease in the OR for asthma exacerbations in the winter, spring and summer seasons. HBE/LBN phenotype had a higher risk of asthma exacerbations among hospitalized pediatric asthma patients in the winter and autumn, while LBE/LBN phenotype had a lower risk in the winter, spring, and summer. Blood eosinophils and neutrophils have been indicated to have a potential influence on pediatric asthma development and severity. HBE/LBN phenotype was associated with increased asthma exacerbations among hospitalized pediatric asthma patients during winter and autumn. Eosinophil and neutrophil predominance exhibited a higher influence on pediatric asthma exacerbations.

Short-term exposure to fine particulate matter and asthma exacerbation: a large population-based case-crossover study in Southern Thailand

BackgroundAsthma exacerbations remain a significant global health issue despite advances in management. Fine particulate matter (PM2.5, particles ≤ 2.5 μm in diameter) is a known trigger for asthma exacerbations. However, studies on the acute effects of PM2.5, particularly in regions with relatively low pollution levels, are limited. This study examined the time-lagged association between daily PM2.5 exposure and asthma exacerbations in Songkhla province, southern Thailand, where PM2.5 concentrations frequently approach the World Health Organization’s (WHO) Global Air Quality Guidelines. Approximately 41% of days during the study period had PM2.5 concentrations below the 2021 Guideline level of 15 µg/m³. Additionally, the province is periodically affected by seasonal transboundary haze from forest fires.MethodsA case-crossover study was conducted using daily PM2.5 and meteorological data from January 2010 to December 2023, alongside health records of asthma patients from Songklanagarind Hospital. District-level daily PM2.5 concentrations were estimated through inverse distance weighted interpolation. Conditional logistic regression, incorporating time-lagged models and cubic splines, was applied.ResultsThe study included 11,848 case days and 39,810 control days, with a mean daily PM2.5 concentration of 18.2 µg/m³. PM2.5 concentrations > 50 µg/m³ were significantly associated with asthma exacerbations at multiple time lags (lag0, lag2, and lag01 to lag03), with odds ratios ranging from 1.41 to 1.64, compared to the lowest concentration group (PM2.5 0–15 µg/m³). Temperature showed no significant effect, while relative humidity was positively associated with asthma exacerbations at lag3, lag06, and lag07. Subgroup analyses revealed associations between PM2.5 exposure and asthma exacerbations at early lags for both males and females. Additionally, children aged 6–11 years and 12–17 years exhibited greater susceptibility to asthma exacerbations, particularly at PM2.5 concentrations of 15–25 µg/m³.ConclusionThis study underscores the short-term effects of PM2.5 on asthma exacerbations, particularly during high-pollution episodes of transboundary haze in regions that generally experience low levels of air pollution. These findings emphasize the importance of achieving the WHO air quality targets to mitigate the health impacts from PM2.5.