Asthma research in China: a five-year review

Scutellarin Alleviates Ovalbumin-Induced Airway Remodeling in Mice and TGF-β-Induced Pro-fibrotic Phenotype in Human Bronchial Epithelial Cells via MAPK and Smad2/3 Signaling Pathways

Asthma is a chronic inflammatory disease characterized by airway hyperresponsiveness (AHR), inflammation, and remodeling. Epithelial-mesenchymal transition (EMT) is an essential player in these alterations. Scutellarin is isolated from Erigeron breviscapus. Its vascular relaxative, myocardial protective, and anti-inflammatory effects have been well established. This study was designed to detect the biological roles of scutellarin in asthma and its related mechanisms. The asthma-like conditions were induced by ovalbumin challenges. The airway resistance and dynamic compliance were recorded as the results of AHR. Bronchoalveolar lavage fluid (BALF) was collected and processed for differential cell counting. Hematoxylin and eosin staining, periodic acid-Schiff staining, and Masson staining were conducted to examine histopathological changes. The levels of asthma-related cytokines were measured by enzyme-linked immunosorbent assay. For in vitro analysis, the 16HBE cells were stimulated with 10 ng/mL transforming growth beta-1 (TGF-β1). Cell migration was estimated by Transwell assays and wound healing assays. E-cadherin, N-cadherin, and α-smooth muscle actin (α-SMA) were analyzed by western blotting, real-time quantitative polymerase chain reaction, immunofluorescence staining, and immunohistochemistry staining. The underlying mechanisms of the mitogen-activated protein kinase (MAPK) and Smad pathways were investigated by western blotting. In an ovalbumin-induced asthmatic mouse model, scutellarin suppressed inflammation and inflammatory cell infiltration into the lungs and attenuated AHR and airway remodeling. Additionally, scutellarin inhibited airway EMT (upregulated E-cadherin level and downregulated N-cadherin and α-SMA) in ovalbumin-challenged asthmatic mice. For in vitro analysis, scutellarin prevented the TGF-β1-induced migration and EMT in 16HBE cells. Mechanistically, scutellarin inhibits the phosphorylation of Smad2, Smad3, ERK, JNK, and p38 in vitro and in vivo. In conclusion, scutellarin can inactivate the Smad/MAPK pathways to suppress the TGF-β1-stimulated epithelial fibrosis and EMT and relieve airway inflammation and remodeling in asthma. This study provides a potential therapeutic strategy for asthma.

Dexamethasone protects against asthma via regulating Hif-1α-glycolysis-lactate axis and protein lactylation

PURPOSE

Asthma can not be eradicated till now and its control primarily relies on the application of corticosteroids. Recently, glycolytic reprogramming has been reportedly contributed to asthma, this study aimed to reveal whether the effect of corticosteroids on asthma control is related to their regulation of glycolysis and glycolysis-dependent protein lactylation.

METHODS

Ovalbumin (OVA) aeroallergen was used to challenge mice and stimulate human macrophage cell line THP-1 following dexamethasone (DEX) treatment. Airway hyperresponsiveness, airway inflammation, the expressions of key glycolytic enzymes and pyroptosis markers, the level of lactic acid, real-time glycolysis and oxidative phosphorylation (OXPHOS), and protein lactylation were analyzed.

RESULTS

DEX significantly attenuated OVA-induced eosinophilic airway inflammation, including airway hyperresponsiveness, leukocyte infiltration, goblet cell hyperplasia, Th2 cytokines production and pyroptosis markers expression. Meanwhile, OVA-induced Hif-1α-glycolysis axis was substantially downregulated by DEX, which resulted in low level of lactic acid. Besides, key glycolytic enzymes in the lungs of asthmatic mice were notably co-localized with F4/80-positive macrophages, indicating metabolic shift to glycolysis in lung macrophages during asthma. This was confirmed in OVA-stimulated THP-1 cells that DEX treatment resulted in reductions in pyroptosis, glycolysis and lactic acid level. Finally, protein lactylation was found significantly increased in the lungs of asthmatic mice and OVA-stimulated THP-1 cells, which were both inhibited by DEX.

CONCLUSION

Our present study revealed that the effect of DEX on asthma control was associated with its suppressing of Hif-1α-glycolysis-lactateaxis and subsequent protein lactylation, which may open new avenues for the therapy of eosinophilic asthma.

A systematic review and meta-analysis of the prevalence and epidemiology of asthma in people over 14 years of age in China

OBJECTIVE

Asthma is a common chronic respiratory disease that seriously affects the health of adults and children. The risk factors for asthma are constantly changing; thus, it is necessary to study the prevalence of asthma and risk factors in different populations. Currently, there have been no epidemiological studies on the prevalence and risk factors of asthma in people over 14 years in mainland China. Therefore, we performed a meta-analysis of the prevalence and risk factors for asthma in mainland China.

METHODS

A literature search was conducted for studies on the epidemiology of asthma in China between 2000 and 2020 using English and Chinese databases. Prevalence and epidemiological information on asthma in people aged >14 years were extracted. Meta-analysis was performed using a random-effects model (If I2>50%) with 95% confidence intervals for forest plots.

RESULTS

Nineteen studies (including data from 345,950 samples) met our evaluation criteria. The overall prevalence of asthma in Chinese adults is 2%, without differences between Northern and Southern China. The prevalence increased after 2010 compared with that before 2010. The prevalence of asthma also increased with age, with people aged 55-64 years being the most affected. The prevalence of asthma was independent of sex and residence area. In conclusion, the prevalence of asthma among adolescents (age >14 years) and adult population in China has increased since 2010.

CONCLUSION

Further studies are necessary to monitor the prevalence of asthma in mainland China. The elderly population also has a high prevalence of asthma, which should be focused on more in the future.

Protective effects of aloin on asthmatic mice by activating Nrf2/HO-1 pathway and inhibiting TGF-β/Smad2/3 pathway

BACKGROUND

Asthma is a severe chronic respiratory disease affecting all age groups with increasing prevalence. Anti-inflammatory strategies are promising options for the treatment of asthma. Although the inhibitory effect of aloin on inflammation has been demonstrated in various diseases, its effect on asthma remains unknown.

METHODS

A mice asthma model was established by treating with ovalbumin (OVA). The effects and mechanism of aloin on the OVA-treated mice were determined by enzyme-linked--immunosorbent serologic assay, biochemical examination, hematoxylin and eosin and Masson's staining, and Western blot assay.

RESULTS

OVA treatment in mice significantly increased the number of total cells, neutrophils, eosinophils, and macrophages and the concentration of interleukin (IL)-4, IL-5, and IL-13, which were attenuated with the administration of aloin. The content of malondialdehyde was enhanced in OVA-treated mice, with the decreased levels of superoxide dismutase and glutathione, which were reversed with aloin treatment. Aloin treatment reduced the airway resistance of OVA-induced mice. The inflammatory cell infiltration around small airways was accompanied by the thickening and contraction of bronchial walls and pulmonary collagen deposition in OVA-treated mice; however, these conditions were ameliorated with aloin treatment. Mechanically, aloin upregulated the expression of nuclear factor erythroid 2-related factor 2 (Nrf2)-heme oxygenase 1 (HO-1) pathway but inhibited the level of transforming growth factor beta-SMAD2/3 genes (TGF-β/Smad2/3) axis in OVA-induced mice.

CONCLUSION

Aloin treatment lessened airway hyperresponsiveness, airway remodeling, inflammation, and oxidative stress in OVA-treated mice, and was closely related to the activation of Nrf2/HO-1 pathway and the weakening of TGF-β/Smad2/3 pathway.

Development and validation of the patient reported outcomes questionnaire of children with asthma in China: A Caregiver's proxy-reported measure

Background

Research on asthma control levels and quality of life is essential for children with asthma during their growth stage. Therefore, it is necessary to develop a questionnaire that can be used for monitoring and evaluating the disease control effectiveness and quality of life of children with asthma in China and to conduct a preliminary evaluation for its reliability, validity, and discriminative ability.

Methods

The questionnaire was created through a literature review and qualitative interviews for a targeted population. Based on the previous work, 30 caregivers of children with asthma and 5 experienced pediatricians reviewed and discussed a collection of items. Then, 72 items were screened and selected to form the draft questionnaire. After three rounds of investigation (with 240, 503, and 360 participants, respectively), the final questionnaire was established according to the evaluation results. The structure of the questionnaire was explored through confirmatory factor analysis. Exploratory factor analysis and variability analysis were applied based on the first two rounds of investigation. Reliability, construct validity, and discriminative ability were evaluated based on the third round of investigation.

Results

The questionnaire contains 6 dimensions and 34 items, and the total cumulative variance contribution rate was 54.96%; Cronbach's α coefficient was 0.91; the split-half reliability coefficient was 0.75, and the test-retest reliability coefficient was 0.74. The children's age, gender, residence, asthma attack in the last three months, caregivers' education background, and monthly income per caregiver were correlated with patient-reported outcomes of children with asthma.

Conclusion

The questionnaire appeared to have good reliability, construct validity, and discriminative ability in children with asthma in China.

Characteristics of medicine use for children with asthma in China: a nationwide population-based study

OBJECTIVE

To analyze the asthma medication use in Chinese children of different age groups, regions, and levels of cities in China, based on the 2015 Healthcare Insurance Data in China.

METHODS

The China Healthcare Insurance Research Association (CHIRA) database was searched for children from 0 to 14 years old diagnosed as asthma based on the "J45" and "J46" coded in ICD-10. A cross-sectional study design was employed.

RESULTS

A total of 308,550 children were identified, all of whom were treated under the coverage of healthcare insurance. Among them, 2,468 children were eligible for inclusion in the present study. Compared with the current status of asthma care in European and American countries, under the guidelines for the diagnosis and treatment of asthma in China, the use percentages of ICS and short-acting β2 receptor agonist in children with asthma in China were lower, but the use percentages of oral corticosteroids, long-acting β2 receptor agonist, and theophylline (especially intravenous theophylline) were higher, especially in the Central and West China.

CONCLUSION

The asthma medication use was attributed to many factors, thus efforts are still needed to further popularize the GINA programs and China's guidelines for asthma diagnosis and treatment, especially in the Central and West China.

Irrational Use of Medicine in the Treatment of Presumptive Asthma Among Rural Primary Care Providers in Southwestern China

Poor knowledge, scarce resources, and lack of or misaligned incentives have been widely documented as drivers of the irrational use of medicine (IUM), which significantly challenges the efficiency of health systems across the globe. However, there is limited understanding of the influence of each factor on IUM. We used detailed data on provider treatment of presumptive asthma cases in rural China to assess the contributions of provider knowledge, resource constraints, and provider behavior on IUM. This study enrolled 370 village providers from southwest China. All providers responded to a clinical vignette to test their knowledge of how to treat presumptive asthma. Resource constraints (“capacity”) were defined as the availability of the prescribed medicines in vignette. To measure provider behavior (“performance”), a subset of providers (104 of 370) were randomly selected to receive unannounced visits by standardized patients (SPs) who performed of presumptive asthma symptoms described in the vignette. We found that, 54% (201/370) of providers provided the vignette-based patients with prescriptions. Moreover, 67% (70/104) provided prescriptions for the SPs. For the vignette, only 10% of the providers prescribed the correct medicines; 38% prescribed only unnecessary medicines (and did not provide correct medicine); 65% prescribed antibiotics (although antibiotics were not required); and 55% prescribed polypharmacy prescriptions (that is, they prescribed five or more different types of drugs). For the SP visits, the numbers were 12%, 51%, 63%, and 0%, respectively. The lower number of medicines in the SP visits was due, in part, to the injections’ not being allowed based on ethical considerations (in response to the vignette, however, 65% of providers prescribed injections). The difference between provider knowledge and capacity is insignificant, while a significant large gap exists between provider performance and knowledge/capacity (for 11 of 17 indicators). Our analysis indicated that capacity constraints play a minor role in driving IUM compared to provider performance in the treatment of asthma cases in rural China. If similar findings hold for other disease cases, this suggests that policies to reduce the IUM in rural China have largely been unsuccessful, and alternatives for improving aligning provider incentives with appropriate drug use should be explored.

Urinary Metabolomic Profiling Reveals Biological Pathways and Predictive Signatures Associated with Childhood Asthma

Background

Despite considerable efforts, the pathogenic mechanisms of asthma are still incompletely understood, due to its heterogeneous nature. However, metabolomics can offer a global view of a biological system, making it a valuable tool for further elucidation of mechanisms and biomarker discovery in asthma.

Methods

GC-MS-based metabolomic analysis was conducted for comparison of urine metabolic profiles between asthmatic children (n=30) and healthy controls (n=30).

Results

An orthogonal projections to latent structures discriminant-analysis model revealed a clear separation of the asthma and control groups (R ² _x =0.137, R ² _y =0.947, Q ²=0.82). A total of 20 differential metabolites were identified as discriminant factors, of which eleven were significantly increased and nine decreased in the asthma group compared to the control group. Pathway-enrichment analysis based on these differential metabolites indicated that sphingolipid metabolism, protein biosynthesis, and citric acid cycle were strongly associated with asthma. Among the identified metabolites, 2-hydroxybutanoic acid showed excellent discriminatory performance for distinguishing asthma from healthy controls, with an AUC of 0.969.

Conclusion

Our study revealed significant changes in the urine metabolome of asthma patients. Several perturbed pathways (eg, sphingolipid metabolism and citric acid cycle) may be related to asthma pathogenesis, and 2-hydroxybutanoic acid could serve as a potential biomarker for asthma diagnosis.

Airborne Bacteria Enriched PM2.5 Enhances the Inflammation in an Allergic Adolescent Mouse Model Induced by Ovalbumin

Air pollution events frequently occur in China during the winter. Most investigations of pollution studies have focused on the physical and chemical properties of PM2.5. Many of these studies have indicated that PM2.5 exacerbates asthma or eosinophil inflammation. However, few studies have evaluated the relationship between bacterial loads in PM2.5, and especially pathogenic bacteria and childhood asthma. Airborne PM2.5 samples from heavily polluted air were collected in Hangzhou, China between December 2014 and January 2015. PM2.5 and ovalbumin (OVA) were intratracheally administered twice in 4-week intervals to induce the allergic pulmonary inflammation in adolescent C57/BL6 mice. PM2.5 exposure caused neutrophilic alveolitis and bronchitis. In the presence of OVA, the levels of the Th2 cytokines IL-4, IL-12, and IL-17 were significantly increased in bronchoalveolar lavage fluids (BALF) after PM2.5 exposure, while eosinophil infiltration and mucin secretion were also induced. In addition to adjuvant effects on OVA-induced allergic inflammation, PM2.5 exposure also led to the maturation of dendritic cells. These results suggest that PM2.5 exposure may aggravate lung eosinophilia and that PM2.5-bound microbial can exacerbate allergic and inflammatory lung diseases.

Dust mite-derived Enterobacterial fimbriae H protein enforces the allergen specific immunotherapy in asthma mice

BACKGROUND

The mite alimentary canal contains plenty of microbiota. It is accepted that some of the microbial products function as adjuvants to speed up immune responses.

OBJECTIVES

We identified five bacterial proteins from dust mite, and Enterobacterial fimbriae H (FimH) was one of them. This study aims to test a hypothesis that the FimH protein enforces immunotherapy in asthmatic mice.

METHODS

Asthmatic mice were treated by allergen specific immunotherapy (ASIT) with rDer f1/f2 or rDer f1/f2 plus FimH. Changes in inflammatory cell infiltration, airway hyperreactivity, frequency of Tregs, splenic CD4⁺IFN-γ⁺ cells, and serum levels of TGF-β, IL-10, IL-13 and IL-17A of asthmatic mice were checked.

RESULTS

ASIT with rDer f1/f2 plus FimH reduced inflammatory cell infiltration, airway hyperreactivity (AHR), and levels of IgE and IgG1 compared to ASIT with rDer f1/f2 alone, but the levels of IgG2a increased. Asthmatic mice that underwent ASIT with rDer f1/f2 plus FimH showed increased frequency of Tregs, splenic CD4⁺IFN-γ⁺ cells, serum levels of TGF-β and IL-10; and deceased splenic CD4⁺IL-4⁺ cells, and serum levels of IL-13 and IL-17A. In vitro study showed FimH triggered IL-10 expression in a concentration dependent manner and facilitated the differentiation of Tregs.

CONCLUSION

Used as an adjuvant, FimH enforces the effect of ASIT in asthmatic mice via augmenting Tregs.

Association between air pollutants and outpatient and emergency hospital visits for childhood asthma in Shenyang city of China

Effects of air pollution on asthma vary in different study areas, and long-term time series research on the effects of air pollution on asthma outpatients and emergency hospital visits has not been conducted in Northeast China. We assessed the impact of air pollutants on the risk of asthma outpatients and emergency hospital visits in Shenyang, China. A distributed lag non-linear model with a Poisson regression was used to assess the short-term effects of air pollutants on asthma outpatient and emergency hospital visits between January 1, 2013 and December 31, 2017. Confounding factors were adjusted using natural cubic splines. Ozone (O₃), carbon monoxide (CO), and suspended particulates < 10 μm in aerodynamic diameter (PM₁₀) were positively associated with the number of asthma hospital visits. The largest cumulative effects of O₃, CO, and PM₁₀ on hospital visits were on lag day 2 (RR = 1.163, 95% CI 1.051-1.287) for 0-5-year-old childhood asthma, on lag day 3 (RR = 1.386, 95% CI 1.136-1.69) for asthma in winter, and on lag day 10 (RR = 1.148, 95% CI 0.942-1.399) for female asthma, respectively. The cumulative effect of air pollution represented by the air quality index (AQI) was largest on lag day 10 for 0-5-year-old childhood asthma with an increase of 28.6% (95% CI 6.5-55.4) hospital visits every IQR increment of the AQI. CO, O₃, and PM₁₀ were the main air pollutants in Shenyang city. Children with bronchitis asthma were more vulnerable to air pollution during the cold season.

The economic burden of medical treatment of children with asthma in China

Background

At present, there are few studies on the economic burden and medical treatment of children with asthma in China. Thus this study aimed to investigate the economic burden of medical treatment of children with asthma in China.

Method

The 2015 China Medical Insurance Research Association (CHIRA) database was searched for patients with asthma from 0 to 14 years old. A cross-sectional study with cost analysis was conducted.

Results

The annual per capita direct medical cost was RMB 525 (US$75) related to asthma. Totaling 58% of the medical expenditure for asthma was covered by insurance in China, the majority of which were direct medical costs. Those that have the highest rates of using antibiotics were central China (100.0%), children aged 3 years and under (63.6%), as well as fourth-tier and fifth-tier cities (77.1%). Outpatient clinics (98.58% vs 1.42%, P < 0.01), tertiary hospitals (62.08% vs 37.92%, P < 0.01), and general hospitals (72.27% vs 27.73%, P < 0.01) were more often visited than the inpatient clinics, secondary and primary as well as the specialized clinics, respectively.

Conclusion

The economic burden of childhood asthma in China is relatively low, and the national medical insurance reduces their economic burden to a large extent. Abuse of antibiotics in treating asthma was found in China. There remain opportunities to strengthen the hierarchical medical system, reducing hospitalization and emergency visits, and ultimately reducing the economic burden of children with asthma.

Establishment of a fluorescent PCR melting curve method for detecting asthma susceptibility using gene SNP typing

Objective: To develop a detection method for single nucleotide polymorphisms (SNPs) of bronchial asthma (BA) susceptibility genes (IL-13, IL-33, and GSDMA) based on fluorescence PCR melting curves.Methods: Peripheral blood samples from 33 patients with BA were collected. DNA was extracted, and positive plasmids were constructed. Probes and primers for fluorescence polymerase chain reaction (PCR) were designed according to IL-13, IL-33, and GSDMA sequences, and the SNPs were separately detected by gene sequencing and fluorescence PCR melting curve.Results: The system was successfully divided into 3 SNPs, including IL-13, IL-33, and GSDMA, and a comparison of sequencing methods showed that the results were completely consistent. The lowest detection limit was 1 ng/reaction, the sensitivity and specificity were 100%, and this method had high repeatability (CV = 2.8%).Conclusion: The fluorescence PCR melting curve method is suitable for the rapid and accurate classification of SNPs. The method is economical, simple, and efficient, and is suitable for the screening of the susceptible gene SNPs in a large-scale population of patients with BA.

Pharmacokinetics of Single and Repeat Doses of Fluticasone Furoate/Umeclidinium/Vilanterol in Healthy Chinese Adults

The pharmacokinetics (PK) and safety of single-inhaler fluticasone furoate/umeclidinium/vilanterol (FF/UMEC/VI) after single and repeat dosing in healthy Chinese adults were assessed. In this open-label study (NCT02837380), subjects received once-daily FF/UMEC/VI 100/62.5/25 µg on day 1 and repeat doses on days 2-7. PK parameters (days 1 and 7) included maximum observed concentration (C_max ) and area under the plasma concentration-time curve (AUC) from time zero (predose) to last time of quantifiable concentration (AUC_0-t ). Terminal phase half-life (t_½ ) on day 1 was estimated. The primary objective was to assess systemic exposure of FF 100 µg, UMEC 62.5 µg, and VI 25 µg following single-inhaler triple therapy on days 1 and 7. On day 1, geometric mean t_½ of UMEC and VI was 0.36 and 0.52 hours, respectively; t_½ of FF was not representative because of nonquantifiable concentration data. On days 1 and 7, geometric mean C_max of FF was 10.46 and 27.32 pg/mL, respectively; C_max of UMEC was 144.14 and 241.35 pg/mL, respectively; and C_max of VI was 120.42 and 196.78 pg/mL, respectively. AUC_0-t of FF was 1.77 and 276.96 pg·h/mL, respectively; AUC_0-t of UMEC was 28.44 and 117.19 pg·h/mL, respectively; and AUC_0-t of VI, 42.46 and 101.12 pg·h/mL, respectively. The PK of FF/UMEC/VI was as expected for the individual-component PK previously reported in healthy Chinese adults. No new safety signals were observed.

Contrasting associations of maternal smoking and pre-pregnancy BMI with wheeze and eczema in children

BACKGROUND

Childhood allergies are dynamic and associated with environmental factors. The influence of prenatal maternal smoking and obesity on childhood allergies and their comorbidities remains unclear, especially in prospective cohorts with serial longitudinal observations.

OBJECTIVE

We examined time trends in the prevalence and comorbidity of childhood allergies, including wheeze, eczema, and rhinoconjunctivitis, using a large-scale, population-based birth cohort in Japan, and assessed the effects of prenatal maternal smoking and BMI on the risk of childhood allergies.

METHODS

Parents completed the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaires about symptoms of allergies and their risk factors at age 1, 2, 4, and 7 years. Complete data from all pre- and postnatal questionnaires at age 1, 2, 4, and 7 were available for 3296 mother-child pairs.

RESULTS

We observed significant overlap of childhood allergies at 1, 2, 4, and 7 years. Maternal serum cotinine during pregnancy was associated with increased risk of wheezing in the children at age 1, 2, and 4 but disappeared at age 7. In contrast, maternal cotinine levels were inversely associated with the prevalence of eczema in children at age 7. We additionally observed that maternal pre-pregnancy BMI, not children's BMI, had a positive association with wheeze and an inverse association with eczema in 7-year-old children, respectively. We did not find any association of examined maternal factors and rhinoconjunctivitis.

CONCLUSIONS

We demonstrated contrasting association of prenatal maternal smoking and high BMI with postnatal wheeze and eczema. For precise assessment of allergy-associated risk factors, we need to contrast risk factors for different allergic diseases since focusing solely on one allergic disease may result in misleading information on the role of different risk factors.

Association Between TGF-β1 Polymorphisms and Asthma Susceptibility Among the Chinese: A Meta-Analysis

OBJECTIVE

Asthma is the most common chronic pulmonary disease in China and is characterized by airway inflammation and episodic airflow obstruction. The aim of this meta-analysis was to evaluate the relation of two transforming growth factor-β1 (TGF-β1) polymorphisms with asthma risk in Chinese population.

METHODS

PubMed, Springer, EMBASE, MEDLINE, CNKI (China National Knowledge Infrastructure), and Wanfang databases were used to search and retrieve relevant eligible case-control studies published through December 2017. The odds ratios (OR) and 95% confidence intervals (CI) were used to evaluate the effect.

RESULTS

A total of 2040 asthma patients and 1952 controls from 12 studies were analyzed. Two polymorphic sites of TGF-β1 gene were identified: -509C/T and +869T/C. We found that the -509C/T polymorphism was associated with increased asthma risk under the heterozygous model (CT vs. CC: OR = 1.40, 95% CI = 1.03-1.90, p = 0.03) and the dominant model (TT+CT vs. CC: OR = 1.41, 95% CI = 1.05-1.90, p = 0.02). Subgroup analyses by age suggested that -509C/T variant was associated with childhood asthma. Analysis of disease severity indicated that this variant was associated with both mild-to-moderate asthma and severe asthma. However, the +869T/C polymorphism was not associated with asthma susceptibility in subgroup analysis by age or disease severity.

CONCLUSIONS

This study demonstrated that the -509C/T polymorphism of the TGF-β1 gene might be a risk factor for asthma in the Chinese population, especially in Chinese children. Further large-scale case-control studies are still required.

Urinary polycyclic aromatic hydrocarbon metabolites and adult asthma: a case-control study

Polycyclic aromatic hydrocarbons (PAHs) exposure was reported to be associated with childhood asthma. However, the quantitative relationship between PAHs exposure and adult asthma and possible inflammatory pathways are less clear. We aimed to investigate potential associations between urinary PAHs metabolites and adult asthma. We enrolled 507 adult asthma cases and 536 matched controls. The concentrations of 12 urinary PAHs metabolites and plasma cytokines of interleukin (IL)-9 and eotaxin were measured. Potential associations between urinary PAHs metabolites and adult asthma were analyzed by logistic regression. The relationships between urinary PAHs metabolites and plasma cytokines were determined by generalized linear regression. After adjusted for covariates, each 1-unit-increase in natural log-transformed concentrations of 2-hydroxyfluorene (2-OHFLU), 4- hydroxyphenanthrene (4-OHPHE), 1-OHPHE, 2-OHPHE, 1-Hydroxypyrene (1-OHPYR) and ∑OH-PAHs were significantly associated with elevated risk of adult asthma with odds ratios of 2.04, 2.38, 2.04, 1.26, 2.35 and 1.34, respectively. And the associations were more pronounced in the subjects who were female, younger than 45 years, smoker and had history of occupational dust exposure. No associations were observed between urinary PAHs metabolites levels and expressions of IL-9 and eotaxin. Our results demonstrated that elevated urinary PAHs metabolites levels were associated with increased risk of asthma in adults.

Serum Eosinophil Cationic Protein Is a Useful Marker for Assessing the Efficacy of Inhaled Corticosteroid Therapy in Children with Bronchial Asthma

Bronchial asthma (BA) is a chronic inflammatory disorder of airways for which the effective therapies include inhaled corticosteroids (ICS) and short-acting β2-adrenoreceptor agonist (SABA). Serum eosinophil cationic protein (ECP) has been reported to reflect the degree of airway inflammation. We, therefore, explored the implication of serum ECP in assessing the efficacy of ICS therapy in BA children. Our prospective randomized control study enrolled 126 BA children and 78 healthy children (the control group). The BA patients were randomly assigned as two groups; 59 children were treated with ICS, twice a day, for three months and 67 patients received SABA inhalation only if necessary. After the 3-month therapy, the serum levels of ECP, endothelin-1, and nitric oxide and the eosinophil percentage (EOS%) in induced sputum were significantly lower in the ICS group, compared with the SABA group, but were still higher than the control group (all P < 0.05). The forced expiratory volume (FEV1%pred) and forced vital capacity (FEV1/FVC) were improved to the levels of the control group after therapy. Pearson correlation analysis presented that higher serum ECP levels were associated with higher EOS% in serum and with lower pulmonary function indices (FEVl%pred and FEV1/FVC). Importantly, the ICS group exhibited higher quality of life scores and lower symptom scores compared with the SABA group (all P < 0.05). ROC results revealed the diagnostic efficiency of serum ECP levels on the efficacy of ICS. In conclusion, measuring serum ECP levels is helpful for assessing the efficacy of ICS therapy in BA children.

Applicability of internet search index for asthma admission forecast using machine learning

OBJECTIVE

This study aimed to determine whether a search index could provide insight into trends in asthma admission in China. An Internet search index is a powerful tool to monitor and predict epidemic outbreaks. However, whether using an internet search index can significantly improve asthma admissions forecasts remains unknown. The long-term goal is to develop a surveillance system to help early detection and interventions for asthma and to avoid asthma health care resource shortages in advance.

METHODS

In this study, we used a search index combined with air pollution data, weather data, and historical admissions data to forecast asthma admissions using machine learning.

RESULTS

Results demonstrated that the best area under the curve in the test set that can be achieved is 0.832, using all predictors mentioned earlier.

CONCLUSION

A search index is a powerful predictor in asthma admissions forecast, and a recent search index can reflect current asthma admissions with a lag-effect to a certain extent. The addition of a real-time, easily accessible search index improves forecasting capabilities and demonstrates the predictive potential of search index.

Disease burden of mild asthma in China

BACKGROUND AND OBJECTIVE

The impact, treatment patterns and control of mild asthma are poorly understood for Chinese patients. This study describes the characteristics, therapeutic interventions and burden of mild asthma on patients residing in major cities of China.

METHODS

The Respiratory Disease Specific Program 2015, a cross-sectional survey, was conducted with Chinese physicians and their patients. The survey assessed clinical characteristics, asthma symptoms, exacerbations, rescue inhaler usage, treatment adherence, asthma control, work and activity impairments and healthcare utilization for patients prescribed Global Initiative for Asthma (GINA) Step 1 or 2 treatment defined mild asthma.

RESULTS

From a total sample of 988 patients, 229 patients met the criteria for mild asthma, with 25.3% classified as Step 1 and 74.7% as Step 2. Overall, 12.6% of patients were considered of high adherence to prescribed treatment. Physicians reported that 75% of patients overall were well controlled, although well-controlled asthma as defined by GINA was achieved in only 14.2% of patients. 26.5% of patients indicated daily use of as-needed rescue medication in the last 4 weeks. 17.8% of patients experienced ≥1 exacerbations in the last 12 months and impaired work productivity was 27.2% overall.

CONCLUSION

Less than 15% of patients were well controlled according to GINA criteria despite physicians reporting the majority of patients were well controlled. Over one-fourth of patients relied on daily rescue inhaler medication, while exacerbation frequency and work and activity impairment were higher than might reasonably be expected in a mild asthmatic population.

Placenta‑derived mesenchymal stem cells improve airway hyperresponsiveness and inflammation in asthmatic rats by modulating the Th17/Treg balance

Mesenchymal stem cells (MSCs) possess reparative and immunoregulatory properties, representing a hope for stem cell-based treatments. However, the mechanisms by which transplanted MSCs affect T helper (Th)17/regulatory T cell (Treg) balance in asthma patients remain unclear. The aim of the present study was to assess the therapeutic effects of human placenta MSCs (hPMSCs) in asthma, and explore the underlying mechanisms; in addition, the impact of hPMSCs transplantation on Th17/Treg balance in lymph and serum samples from asthmatic animals was evaluated. Sprague-Dawley rats were sensitized and challenged with ovalbumin (OVA). Administration of hPMSCs from human placenta resulted in increased Th17 and Treg in lymph samples compared with peripheral blood specimens. Enhanced pause values in OVA-treated animals were significantly higher than those in the control and hPMSCs treatment groups. The numbers of total cells, macrophages, neutrophils, and eosinophils were markedly increased in the OVA group compared with those of control + hPMSCs and control groups. In addition, interleukin 10, forkhead box P3 (Foxp3) and Treg levels in lymph, peripheral blood and lung tissue samples from asthma rats were increased significantly following hPMSC transplantation. Furthermore, Foxp3 protein levels increased, while those of RAR-related orphan receptor γ (RORγt) decreased after hPMSCs transplantation compared with the asthma group. Reduced IL-17, RORγt and Th17 levels were accompanied by reduced inflammatory cell infiltration, sub-epithelial smooth layer attenuation and mucus production in lung tissues. These results suggest that hPMSCs may improve airway hyperresponsiveness and inflammation by regulating the Th17/Treg balance in rats with asthma.

Markov Chain-Based Acute Effect Estimation of Air Pollution on Elder Asthma Hospitalization

Background

Asthma caused substantial economic and health care burden and is susceptible to air pollution. Particularly, when it comes to elder asthma patient (older than 65), the phenomenon is more significant. The aim of this study is to investigate the Markov-based acute effects of air pollution on elder asthma hospitalizations, in forms of transition probabilities.

Methods

A retrospective, population-based study design was used to assess temporal patterns in hospitalizations for asthma in a region of Sichuan province, China. Approximately 12 million residents were covered during this period. Relative risk analysis and Markov chain model were employed on daily hospitalization state estimation.

Results

Among PM2.5, PM10, NO₂, and SO₂, only SO₂ was significant. When air pollution is severe, the transition probability from a low-admission state (previous day) to high-admission state (next day) is 35.46%, while it is 20.08% when air pollution is mild. In particular, for female-cold subgroup, the counterparts are 30.06% and 0.01%, respectively.

Conclusions

SO₂ was a significant risk factor for elder asthma hospitalization. When air pollution worsened, the transition probabilities from each state to high admission states increase dramatically. This phenomenon appeared more evidently, especially in female-cold subgroup (which is in cold season for female admissions). Based on our work, admission amount forecast, asthma intervention, and corresponding healthcare allocation can be done.

Curcumin ameliorates asthmatic airway inflammation by activating nuclear factor-E2-related factor 2/haem oxygenase (HO)-1 signalling pathway

Previous studies have shown that curcumin alleviates asthma in vivo. However, the relationship between curcumin and the nuclear factor-E2-related factor 2 (Nrf2)/haem oxygenase (HO)-1 pathway in asthma treatment remains unknown. The aim of the present study was to investigate the mechanisms of curcumin involved in the amelioration of airway inflammation in a mouse asthma model. Curcumin was administrated to asthmatic mice, and bronchoalveolar lavage fluid was collected. Inflammatory cell infiltration was measured by Giemsa staining. Immunoglobulin E production in bronchoalveolar lavage fluid was measured by enzyme-linked immunosorbent assay. Histological analyses were evaluated with haematoxylin-eosin and periodic acid-Schiff staining. Airway hyperresponsiveness was examined by whole-body plethysmography. Nuclear factor-E2-related factor 2, HO-1, nuclear factor-κB and inhibitory κB/p-inhibitory κB levels in lung tissues were detected by western blot, and Nrf2 activity was measured by electrophoretic mobility shift assay. Tumour necrosis factor-α, interleukin (IL)-1β, and IL-6 levels in the small interfering RNA-transfected cells were detected by enzyme-linked immunosorbent assay. Curcumin treatment significantly reduced immunoglobulin E production, attenuated inflammatory cell accumulation and goblet cell hyperplasia, and ameliorated mucus secretion and airway hyperresponsiveness. Nuclear factor-E2-related factor 2 and HO-1 levels in lung tissues were significantly increased. Meanwhile, Nrf2 activity was enhanced. Nuclear factor-κB and p-inhibitory κB levels were elevated in the lung tissue of ovalbumin-challenged mice. Both were restored to normal levels after curcumin treatment. Haem oxygenase-1 and nuclear Nrf2 levels were enhanced in dose- and time-dependent manners in curcumin-treated RAW264.7 cells. Curcumin blocked lipopolysaccharide-upregulated expression of tumour necrosis factor-α, IL-1β, and IL-6. After the cells were transfected with HO-1 or Nrf2 small interfering RNA, lipopolysaccharide-induced pro-inflammation cytokine expression was significantly restored. In summary, curcumin might alleviate airway inflammation in asthma through the Nrf2/HO-1 pathway, potentially making it an effective drug in asthma treatment.

Air Pollutants, Climate, and the Prevalence of Pediatric Asthma in Urban Areas of China

Background. Prevalence of childhood asthma varies significantly among regions, while its reasons are not clear yet with only a few studies reporting relevant causes for this variation. Objective. To investigate the potential role of city-average levels of air pollutants and climatic factors in order to distinguish differences in asthma prevalence in China and explain their reasons. Methods. Data pertaining to 10,777 asthmatic patients were obtained from the third nationwide survey of childhood asthma in China's urban areas. Annual mean concentrations of air pollutants and other climatic factors were obtained for the same period from several government departments. Data analysis was implemented with descriptive statistics, Pearson correlation coefficient, and multiple regression analysis. Results. Pearson correlation analysis showed that the situation of childhood asthma was strongly linked with SO2, relative humidity, and hours of sunshine (p < 0.05). Multiple regression analysis indicated that, among the predictor variables in the final step, SO2 was found to be the most powerful predictor variable amongst all (β = -19.572, p < 0.05). Furthermore, results had shown that hours of sunshine (β = -0.014, p < 0.05) was a significant component summary predictor variable. Conclusion. The findings of this study do not suggest that air pollutants or climate, at least in terms of children, plays a major role in explaining regional differences in asthma prevalence in China.

Acute effects of air pollution on asthma hospitalization in Shanghai, China

Air pollution has been accepted as an important contributor to asthma development and exacerbation. However, the evidence is limited in China. In this study, we investigated the acute effect of air pollution on asthma hospitalization in Shanghai, China. We applied over-dispersed generalized additive model adjusted for weather conditions, day of the week, long-term and seasonal trends. An interquartile range increase in the moving average concentrations of PM10, SO2, NO2 and BC on the concurrent day and previous day corresponded to 1.82%, 6.41%, 8.26% and 6.62% increase of asthmatic hospitalization, respectively. The effects of SO2 and NO2 were robust after adjustment for PM10. The associations appeared to be more evident in the cool season than in the warm season. Our results contribute to the limited data in the scientific literature on acute effects of air pollution on asthma in high exposure settings, which are typical in developing countries.

An aerosol formulation of R-salbutamol sulfate for pulmonary inhalation

An aerosol formulation containing 7.5 mg of R-salbutamol sulfate was developed. The aerosol was nebulized with an air-jet nebulizer, and further assessed according to the new European Medicines Agency (EMA) guidelines. A breath simulator was used for studies of delivery rate and total amount of the active ingredient at volume of 3 mL. A next generation impactor (NGI) with a cooler was used for analysis of the particle size and in vitro lung deposition rate of the active ingredient at 5 °C. The anti-asthmatic efficacy of the aerosol formulation was assessed in guinea pigs with asthma evoked by intravenous injection of histamine compared with racemic salbutamol. Our results show that this aerosol formulation of R-salbutamol sulfate met all the requirements of the new EMA guidelines for nebulizer. The efficacy of a half-dose of R-salbutamol equaled that of a normal dose of racemic salbutamol.