Obesity, Inflammation, and Severe Asthma: an Update

Effects of menopause and fat mass in asthmatic inflammation

INTRODUCTION

Female hormones and obesity have an impact on women with asthma. We aimed to describe how these components affect asthma inflammatory processes.

METHODS

Sex hormones [FSH, LH, estradiol (E2), estrone (E1), testosterone and Δ4 androstenedione (A4)] and serum IL1β, IL13, IL17a, IL-5, IL6, TNF-a were measured from 11 to18 pre- and postmenopausal women with asthma.

RESULTS

Premenopausal normal weight women revealed higher levels of IL5 and IL17a than obese women on both days of the menstrual cycle (IL5: D1: 6.4 vs 1.4 pg/ml, p = .036 and D14: 3 vs 1.4 pg/ml, p = .045 and IL17a: D1: 13.7 pg/ml vs 10.6 pg/ml and D14: 12.4 pg/ml vs 10.6 pg/ml, p = .009, respectively). In premenopausal women on D1, Δ4 Androstenedione was positively correlated with IL1β (p = .016, r = 0.733), whereas on D14, Estradiol with IL1β (p = .009, r = -.768) and TNF-a with Testosterone (p = .004, r = -0.816), and Δ4 Androstenedione (p = .002, r = -0.841) negatively. In postmenopausal women, TNF-a was negatively associated with FSH (p = .004, r = -0.638), but positively with Testosterone (p = .025, r = 0.526) and IL10 also positively with Estradiol (p = .007, r = 0.610).

CONCLUSION

Obesity shows a protective role in asthma through the suppression of IL5 and IL17. Estrogens seem to inhibit Th1 and Th2 inflammation, while androgens have a dual role with negative and positive correlations with neutrophilic biomarkers.

AMPK Regulates M1 Macrophage Polarization through the JAK2/STAT3 Signaling Pathway to Attenuate Airway Inflammation in Obesity-Related Asthma

Abstract-Obesity-related asthma is primarily characterized by nonallergic inflammation, with pathogenesis involving oxidative stress, metabolic imbalance, and immunoinflammatory mechanisms. M1 macrophages, which predominantly secrete pro-inflammatory factors, mediate insulin resistance and systemic metabolic inflammation in obese individuals. Concurrently, adenosine monophosphate-activated protein kinase (AMPK) serves as a critical regulator of intracellular energy metabolism and is closely associated with macrophage activation. However, their specific roles and associated mechanisms in obesity-related asthma remain to be explored. In this study, we investigated the macrophage polarization status and potential interventional mechanisms through obesity-related asthmatic models and lipopolysaccharide (LPS) -treated RAW264.7 cell with a comprehensive series of evaluations, including HE, PAS and Masson staining of lung histopathology, immunohistochemical staining, immunofluorescence technology, qRT-PCR, Western Blot, and ELISA inflammatory factor analysis. The results revealed M1 macrophage polarization in obesity-related asthmatic lung tissue alongside downregulation of AMPK expression. Under LPS stimulation, exogenous AMPK activation attenuated M1 macrophage polarization via the Janus kinase 2/ signal transducer and activator of transcription 3 (JAK2/STAT3) signaling pathway. Additionally, in obesity-related asthmatic mice, AMPK activation was found to alleviate airway inflammation by regulating M1 macrophage polarization, the mechanism closely associated with the JAK2/STAT3 pathway. These findings not only advance our understanding of macrophage polarization in obesity-related asthma, but also provide new therapeutic targets for its treatment.

TRP channels associated with macrophages as targets for the treatment of obese asthma

Globally, obesity and asthma pose significant health challenges, with obesity being a key factor influencing asthma. Despite this, effective treatments for obese asthma, a distinct phenotype, remain elusive. Since the discovery of transient receptor potential (TRP) channels in 1969, their value as therapeutic targets for various diseases has been acknowledged. TRP channels, present in adipose tissue cells, influence fat cell heat production and the secretion of adipokines and cytokines, which are closely associated with asthma and obesity. This paper aims to investigate the mechanisms by which obesity exacerbates asthma-related inflammation and suggests that targeting TRP channels in adipose tissue could potentially suppress obese asthma and offer novel insights into its treatment.

Obesity-related asthma and its relationship with microbiota

Obesity and asthma are global public health problems. Obesity-related asthma is a special phenotype of asthma with a complex pathogenesis. Its occurrence and development are related to mechanical compression, inflammatory response, metabolic regulation, gene regulation, and vitamin D deficiency. Different treatment strategies used in the process of weight loss have a beneficial impact on asthma. Alterations in gut and airway microbial community structure and their metabolites may also contribute to obesity-related asthma. The role of the Th17/Treg balance in the gut microbiota regulating the immune responses and host metabolism is important. Therapeutic measures associated with the gut microbiota variety may contribute to improving chronic inflammation associated with obesity by regulating the Th17/Treg balance. An early reduction in microbial diversity can predict the development of asthma and lead to allergy through an imbalance of Th2/Th1 responses. Short-chain fatty acids (SCFAs) regulate the differentiation and activation of regulatory T cells, thereby regulating immune homeostasis in the lung to suppress allergic inflammation and weight gain. Therefore, clarifying the microbial mechanism of obesity-related asthma has important guiding significance for clinical treatment. In this review, we used the following terms: "asthma and obesity" and "obesity-related asthma", combining "phenotype", "airway inflammation" and "lung function", and reviewed the characteristics and pathogenesis of obesity-related asthma, the relationship between the gut and airway microbiota and obesity-related asthma, and the current treatment measures for the disease.

Effects of biological therapies on patients with Type-2 high asthma and comorbid obesity

Over 20 million adults and 6 million children in the United States (US) have asthma, a chronic respiratory disease characterized by airway inflammation, bronchoconstriction, and mucus hypersecretion. Obesity, another highly prevalent disease in the US, is a major risk factor for asthma and a significant cause of diminished asthma control, increased submucosal eosinophilia, and reduced quality of life. A large subgroup of these patients experiences severe symptoms and recurrent exacerbations despite maximal dosage of standard asthma therapies. In the past two decades, the development of biological therapies has revolutionized the field and advanced our understanding of type 2 inflammatory biomarkers. However, patients with obesity and comorbid asthma are not principally considered in clinical trials of biologics. Large landmark cluster analyses of patients with asthma have consistently identified specific asthma phenotypes that associate with obesity but may be differentiated by age of asthma onset and inflammatory cell profiles in sputum. These patterns suggest that biologic processes driving asthma pathology are heterogenous among patients with obesity. The biological mechanisms driving pathology in patients with asthma and comorbid obesity are not well understood and likely multifactorial. Future research needs to be done to elicit the cellular and metabolic functions in the relationship of obesity and asthma to yield the best treatment options for this multiplex condition. In this review, we explore the key features of type 2 inflammation in asthma and discuss the effectiveness, safety profile, and research gaps regarding the currently approved biological therapies in asthma patients with obesity.

Nomenclature of allergic diseases and hypersensitivity reactions: Adapted to modern needs: An EAACI position paper

The exponential growth of precision diagnostic tools, including omic technologies, molecular diagnostics, sophisticated genetic and epigenetic editing, imaging and nano-technologies and patient access to extensive health care, has resulted in vast amounts of unbiased data enabling in-depth disease characterization. New disease endotypes have been identified for various allergic diseases and triggered the gradual transition from a disease description focused on symptoms to identifying biomarkers and intricate pathogenetic and metabolic pathways. Consequently, the current disease taxonomy has to be revised for better categorization. This European Academy of Allergy and Clinical Immunology Position Paper responds to this challenge and provides a modern nomenclature for allergic diseases, which respects the earlier classifications back to the early 20th century. Hypersensitivity reactions originally described by Gell and Coombs have been extended into nine different types comprising antibody- (I-III), cell-mediated (IVa-c), tissue-driven mechanisms (V-VI) and direct response to chemicals (VII). Types I-III are linked to classical and newly described clinical conditions. Type IVa-c are specified and detailed according to the current understanding of T1, T2 and T3 responses. Types V-VI involve epithelial barrier defects and metabolic-induced immune dysregulation, while direct cellular and inflammatory responses to chemicals are covered in type VII. It is notable that several combinations of mixed types may appear in the clinical setting. The clinical relevance of the current approach for allergy practice will be conferred in another article that will follow this year, aiming at showing the relevance in clinical practice where various endotypes can overlap and evolve over the lifetime.

Severity of adult-onset asthma - a matter of blood neutrophils and severe obesity

BACKGROUND

Adult-onset asthma is associated with a poor treatment response. The aim was to study associations between clinical characteristics, asthma control and treatment in adult-onset asthma.

METHODS

Previous participants within the population-based Obstructive Lung Disease in Northern Sweden studies (OLIN) were in 2019-2020 invited to clinical examinations including structured interviews, spirometry, fractional exhaled nitric oxide (FeNO), skin prick test and blood sampling. In total, n = 251 individuals with adult-onset asthma (debut >15 years of age) were identified. Uncontrolled asthma was defined according to ERS/ATS and treatment step according to GINA (2019).

RESULTS

Among individuals with uncontrolled asthma (34%), severe obesity (16.3% vs 7.9%, p = 0.041) and elevated levels of blood neutrophils, both regarding mean level of blood neutrophils (4.25*109/L vs 3.67*109/L, p = 0.003), and proportions with ≥4*109/L (49.4% vs 33.3%, p = 0.017) and ≥5*109/L (32.1% vs 13.7%, p < 0.001) were more common than among those with controlled asthma. Adding the dimension of GINA treatment step 1-5, individuals with uncontrolled asthma on step 4-5 treatment had the highest proportions of blood neutrophils ≥5*109/L (45.5%), severe obesity (BMI≥35, 26.1%), dyspnea (mMRC≥2) (34.8%), and most impaired lung function in terms of FEV1%<80% of predicted (42.9%), FEV1

CONCLUSION

This study indicates that in adult-onset asthma, primarily non-type-2 characteristics such as obesity and blood neutrophils associate with poor asthma control and higher doses of inhaled corticosteroids.

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Key Words

• Body mass index
• Eosinophils
• Epidemiology
• Follow-up studies
• Neutrophils
• Sweden

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MESH Headings

• Humans
• Adult
• Neutrophils
• Obesity, Morbid/complications
• Nitric Oxide/therapeutic use
• Asthma/drug therapy
• Eosinophils
• Obesity/complications

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Affiliation(s)

Sofia Winsa-Lindmark Umeå University, Department of Public Health and Clinical Medicine, Section for Sustainable Health/The OLIN Unit, Sweden.
Caroline Stridsman Umeå University, Department of Public Health and Clinical Medicine, The OLIN Unit, Sweden
Axel Sahlin Umeå University, Department of Public Health and Clinical Medicine, Section for Sustainable Health/The OLIN Unit, Sweden
Linnea Hedman Umeå University, Department of Public Health and Clinical Medicine, Section for Sustainable Health/The OLIN Unit, Sweden
Nikolai Stenfors Umeå University, Department of Public Health and Clinical Medicine, The OLIN Unit, Sweden
Tomi Myrberg Umeå University, Department of Surgical and Perioperative Sciences, Anesthesiology and Intensive Care Medicine, Sweden
Anne Lindberg Umeå University, Department of Public Health and Clinical Medicine, The OLIN Unit, Sweden
Eva Rönmark Umeå University, Department of Public Health and Clinical Medicine, Section for Sustainable Health/The OLIN Unit, Sweden
Helena Backman Umeå University, Department of Public Health and Clinical Medicine, Section for Sustainable Health/The OLIN Unit, Sweden

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Obesity-Associated Non-T2 Mechanisms in Obese Asthmatic Individuals

Obesity and asthma are two common health issues that have shown increased prevalence in recent years and have become a significant socioeconomic burden worldwide. Obesity increases asthma incidence and severity. Obese asthmatic individuals often experience increased exacerbation rates, enhanced airway remodeling, and reduced response to standard corticosteroid therapy. Recent studies indicate that obesity-associated non-T2 factors such as mechanical stress, hyperinsulinemia, systemic inflammation, adipose tissue mediators, metabolic dysregulation, microbiome dysbiosis, and high-fat-diet are responsible for increased asthma symptoms and reduced therapeutic response in obese asthmatic individuals. This manuscript reviews the recent findings highlighting the role of obesity-associated factors that contribute to airway hyper-reactivity, airway inflammation and remodeling, and immune cell dysfunction, consequently contributing to worsening asthma symptoms. Furthermore, the review also discusses the possible future therapies that might play a role in reducing asthma symptoms by diminishing the impact of obesity-associated non-T2 factors.

Prevalence of active and passive smoking among asthma and asthma-associated emergency admissions: a nationwide prevalence survey study

Asthma affects 7% of children and 8% of adults in the United States. There is a paucity of studies examining the association between passive smoking and an increased risk of asthma exacerbations that led the authors to examine the association between various modes of smoking and rates of asthma exacerbations. A retrospective cross-sectional/case-control study was conducted using the National Health and Nutrition Examination Survey dataset (2013-2018). Out of 312,979 respondents, 35,758 (11.43%) had a history of asthma, 9083 (2.9%) had asthma attacks in the past year, and 4731 (1.51%) had asthma-related emergency room admissions in the past year. Prevalence of asthma-related emergency admissions were higher among active cigarette smoking (46.25 vs 35.46%), e-cigarette smoking (26.63 vs 16.07%), and passive smoking at home (37.53 vs 25.67%), workplace passive smoking (14.35 vs 12.11%), in bar (32.38 vs 26.16%), and car (26.21 vs 14.44%) (p < 0.0001). In multivariate regression analysis, we found regular cigarette smoking (OR 1.13, 95% confidence interval (CI) 1.009-1.260, p = 0.0252), e-cigarette (OR 2.13, 95% CI 1.92-2.36, p = 0.0043), cigar use (OR 1.21, 95% CI 1.1-1.33, p < 0.001), ultra-long cigarette length (OR 4.85, 95% CI 3.33-7.06, p < 0.0001), and passive smoking (OR 5.25, 95% CI 3.43-8.06, p < 0.0001) were associated with increased rates of asthma exacerbations over last 12 months. The study shows increased odds of asthma exacerbations among those using ultra-long cigarettes, e-cigarettes, and cigars. Consequently, passive inhalation from even a single smoker in the home, workplace, bars and cars is associated with worsening outcomes in asthma patients.

Mendelian randomization analysis to analyze the genetic causality between different levels of obesity and different allergic diseases

BACKGROUND

The causal relationship between obesity and different allergic diseases remains controversial.

METHODS

The Two Sample MR package and Phenoscanner database were used to obtain and filter Genome-Wide Association Study (GWAS) data from the Open GWAS database. Mendelian randomization (MR) analysis was used to study the causal relationship between different levels of obesity and different allergic diseases. The data sets related to obesity and asthma were obtained from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were screened by the limma package. Cluster Profiler and GO plot packages were used for enrichment analysis to verify the results of MR analysis.

RESULTS

Two-sample MR analysis showed a causal relationship between obesity and childhood allergy (age < 16), allergic asthma and atopic dermatitis (P < 0.05). In addition, there was also a causal relationship between allergic asthma and obesity (P < 0.05), while there was no genetic causal relationship between obesity and allergic rhinitis, eczema, lactose intolerance and so on (P > 0.05). Subgroup analysis revealed a causal relationship between both class 1 and class 2 obesity and childhood allergy (age < 16) (P < 0.05). Obesity class 1 was associated with allergic asthma, while obesity class 3 was associated with atopic dermatitis (P < 0.05). Bioinformatics analysis shows that there were common DEGs between obesity and allergic asthma.

CONCLUSION

Obesity is a risk factor for childhood allergy (age < 16), allergic asthma and atopic dermatitis, while allergic asthma is also a risk factor for obesity. Class 1 and class 2 obesity are both causally associated with childhood allergy (age < 16). In addition, there is a causal relationship between milder obesity and allergic asthma, while heavier obesity is causally related to atopic dermatitis.

The Role of Diet and Nutrition in Allergic Diseases

Allergic diseases are a set of chronic inflammatory disorders of lung, skin, and nose epithelium characterized by aberrant IgE and Th2 cytokine-mediated immune responses to exposed allergens. The prevalence of allergic diseases, including asthma, allergic rhinitis, and atopic dermatitis, has increased dramatically worldwide in the past several decades. Evidence suggests that diet and nutrition play a key role in the development and severity of allergic diseases. Dietary components can differentially regulate allergic inflammation pathways through host and gut microbiota-derived metabolites, therefore influencing allergy outcomes in positive or negative ways. A broad range of nutrients and dietary components (vitamins A, D, and E, minerals Zn, Iron, and Se, dietary fiber, fatty acids, and phytochemicals) are found to be effective in the prevention or treatment of allergic diseases through the suppression of type 2 inflammation. This paper aims to review recent advances in the role of diet and nutrition in the etiology of allergies, nutritional regulation of allergic inflammation, and clinical findings about nutrient supplementation in treating allergic diseases. The current literature suggests the potential efficacy of plant-based diets in reducing allergic symptoms. Further clinical trials are warranted to examine the potential beneficial effects of plant-based diets and anti-allergic nutrients in the prevention and management of allergic diseases.

Hormonal Contraceptives Are Associated With an Increase in Incidence of Asthma in Women

BACKGROUND

Use of exogenous female sex hormones is associated with the development of asthma, but the question of whether the effect is protective or harmful remains unresolved.

OBJECTIVE

To investigate whether initiation of hormonal contraceptive (HC) treatment was associated with development of asthma.

METHODS

We performed a register-based, exposure-matched cohort study including women who initiated HC treatment of any kind between 10 and 40 years of age and compared the incidence of asthma with women who did not initiate HCs. Asthma was defined as 2 redeemed prescriptions of inhaled corticosteroids within 2 years. Data were analyzed using Cox regression models adjusted for income and urbanization.

RESULTS

We included 184,046 women with a mean age of 15.5 years (SD 1.5 y), in which 30,669 initiated HC treatment and 153,377 did not. We found that initiation of HCs was associated with an increased hazard ratio (HR) of developing new asthma by 1.78 (95% CI 1.58-2.00; P < .001). The cumulative risk of new asthma was 2.7% after 3 years among users of HCs compared with 1.5% in nonusers. In the different subtypes of HCs, second- and third-generation contraceptives carried significant associations (second-generation HR 1.76; 95% CI 1.52-2.03; P < .001; third-generation HR 1.62 95% CI 1.23-2.12; P < .001). The association with increased incidence was seen only in women younger than 18 years.

CONCLUSIONS

In this study, first-time users of HCs had an increased incidence of asthma compared with nonusers. Clinicians prescribing HCs should be aware that airway symptoms may develop.

Serum CDC42 reflects the exacerbation risk and severity, Th1/2 cell imbalance and inflammation in asthmatic children

Aim: To explore the clinical implication of serum CDC42 in asthmatic children. Materials & methods: Serum CDC42 from 80 asthmatic children experiencing exacerbation, 80 asthmatic children in remission and 40 healthy controls was detected by ELISA. Results: CDC42 was highest in asthmatic children experiencing exacerbation followed by asthmatic children in remission and healthy controls (p < 0.001). Among asthmatic children experiencing exacerbation, CDC42 positively correlated with exacerbation severity (p = 0.011), Th2 (p = 0.017), TNF-α (p < 0.001), IL-6 (p = 0.009) and IL-8 (p = 0.008) and negatively correlated with Th1/Th2 ratio (p = 0.028). In asthmatic children in remission, CDC42 correlated with lower Th1/Th2 ratio (p = 0.028) and higher TNF-α (p = 0.026). In healthy controls, CDC42 showed no correlation with Th1/2 or inflammatory cytokines. Conclusion: Circulating CDC42 reflects exacerbation risk, Th1/2 imbalance and inflammation in asthmatic children.

Mediterranean Diet and Airway Inflammation in School-Aged Children

There seems to exist an intricate relationship between airway inflammation, body mass index (BMI), and diet. The intake of specific foods or food groups has been suggested to suppress the oxidative stress and inflammatory processes that characterize airway inflammation, but little is known about dietary patterns and their complex interplay with BMI and airway inflammation. Therefore, this cross-sectional study aimed to explore the association between adherence to the Mediterranean diet (MD), a characteristic European diet, and levels of airway inflammation in school-aged children, taking into account their BMI. This cross-sectional analysis comprised 660 children: 49.1% females, 7-12 years old. Adherence to the MD was assessed through the alternate Mediterranean score (aMED). Higher scores represent a healthier diet (0-8). Airway inflammation was assessed measuring exhaled fractional nitric oxide (eNO). Two categories of BMI were considered: non-overweight/non-obese (p < 85th) and overweight/obese (p ≥ 85th). The associations between diet and airway inflammation were estimated using logistic regression models. Higher scores of the aMED were associated with decreased odds of having eNO ≥ 35 ppb, but only in non-overweight/non-obese children (OR = 0.77; 95% CI, 0.61-0.97). For overweight/obese children, the previous association was not significant (OR = 1.57, 95% CI, 0.88-2.79). Our findings suggest that adherence to the MD is associated with lower levels of airway inflammation among non-overweight/non-obese children.

Global, regional, and national burden of asthma and its attributable risk factors from 1990 to 2019: a systematic analysis for the Global Burden of Disease Study 2019

BACKGROUND

The burden of asthma in terms of premature death or reduced quality of life remains a huge issue. It is of great importance to evaluate asthma burden geographically and time trends from 1990 to 2019 and to assess the contributions of age, period, and cohort effects at global level.

METHODS

Asthma prevalence, deaths, and disability adjusted life years (DALYs) as well as risk-attributable burden were collected from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 database and were compared by age and sex. The Smoothing Splines models were used to estimate the relationship between asthma DALYs and the sociodemographic index (SDI). The Age-Period-Cohort model was used to determine effects of ages, periods, and birth cohorts on disease rates.

RESULTS

Between 1990 and 2019, the declines were 24.05% (95% uncertainty interval [UI] - 27.24 to - 20.82) in age-standardized asthma prevalence, 51.3% (- 59.08 to - 43.71) in mortality, and 42.55% (- 48.48 to - 36.61) in DALYs rate. However, the burden of asthma continued to rise, with an estimated 262.41 million prevalent cases globally (95% UI 224.05 to 309.45). Asthma caused greater DALYs in females than in males among people aged 20 years and older. The lowest age-standardized DALYs rate was observed at a SDI of approximately 0.70. The Longitudinal age curves showed an approximate W-shaped pattern for asthma prevalence and a likely J-shaped pattern for asthma mortality. The period effect on prevalence and mortality of asthma decreased from 1990 to 2019. Compared with the 1955-1959 birth cohort, the prevalence relative risk (RR) of asthma was highest in the 1905-1909 birth cohort, whereas the mortality RR continued to decline. At the global level, the percentages of high body-mass index, occupational asthmagens, and smoking contributing to DALYs due to asthma were 16.94%, 8.82%, and 9.87%, respectively.

CONCLUSIONS

Although the age-standardized rates of asthma burden declined in the past 30 years, the overall burden of asthma remains severe. High body mass index becomes the most important risk factor for DALYs due to asthma at the global level.

Emergent Inflammatory Markers and Echocardiographic Indices in Patients with Bronchial Asthma

Asthma is a heterogeneous disease, characterized by chronic inflammation and oxidative stress of the airways. Several inflammatory pathways including activation of the receptor for advanced glycation end products (RAGE) have been described in the course of the disease. DJ-1 is a redox-sensitive protein with multifaceted roles in mast cell homeostasis and an emerging role in the pathogenesis of asthma. Moreover, cardiac function abnormalities have been described via echocardiography in patients with asthma. The main aim of this study was to investigate the plasma levels of RAGE, its ligands and DJ-1 in asthmatic patients pre- and post-treatment along with echocardiographic indices of cardiovascular function. The study population was divided into two groups. Group A included 13 patients with newly diagnosed bronchial asthma who were free of treatment for at least two weeks and Group B included 12 patients without asthma. An echocardiography examination was performed on all patients. The plasma levels of RAGE, its ligands (AGEs, S100A12, S100B, S100A8/A9), the interleukins (IL-6, IL-1β) and DJ-1 were measured. No differences were noted among the two groups for baseline characteristics and echocardiographic indices of cardiac function. In Group A, 31% suffered from mild asthma, 54% from moderate asthma and 15% from severe asthma. Plasma levels of IL-6, AGEs and AGE/RAGE ratio were increased and those of S100A12 and DJ-1 were decreased in asthmatics. Pharmacotherapy with corticosteroids/β2-agonists decreased IL-6, and AGEs, and increased DJ-1. In search of novel approaches in diagnosing and treating patients with asthma, S100A12, ratio AGE/sRAGE, and DJ-1 in addition to IL-6 may prove to be useful tools.

Highlighting the importance of healthy sleep patterns in the risk of adult asthma under the combined effects of genetic susceptibility: a large-scale prospective cohort study of 455 405 participants

BACKGROUND

Individuals with asthma usually have comorbid sleep disturbances; however, whether sleep quality affects asthma risk is still unclear. We aimed to determine whether poor sleep patterns could increase the risk of asthma and whether healthy sleep patterns could mitigate the adverse effect of genetic susceptibility.

METHODS

A large-scale prospective study was performed in the UK Biobank cohort involving 455 405 participants aged 38-73 years. Polygenic risk scores (PRSs) and comprehensive sleep scores, including five sleep traits, were constructed. A multivariable Cox proportional hazards regression model was used to investigate the independent and combined effects of sleep pattern and genetic susceptibility (PRS) on asthma incidence. Subgroup analysis across sex and sensitivity analysis, including a 5-year lag, different covariate adjustments and repeat measurements were performed.

RESULTS

A total of 17 836 individuals were diagnosed with asthma during over 10 years of follow-up. Compared with the low-risk group, the HRs and 95% CIs for the highest PRS group and the poor sleep pattern group were 1.47 (95% CI: 1.41 to 1.52) and 1.55 (95% CI: 1.45 to 1.65), respectively. A combination of poor sleep and high genetic susceptibility led to a twofold higher risk compared with the low-risk combination (HR (95% CI): 2.22 (1.97 to 2.49), p<0.001). Further analysis showed that a healthy sleep pattern was associated with a lower risk of asthma in the low, intermediate and high genetic susceptibility groups (HR (95% CI): 0.56 (0.50 to 0.64), 0.59 (0.53 to 0.67) and 0.63 (0.57 to 0.70), respectively). Population-attributable risk analysis indicated that 19% of asthma cases could be prevented when these sleep traits were improved.

CONCLUSIONS

Individuals with poor sleep patterns and higher genetic susceptibility have an additive higher asthma risk. A healthy sleep pattern reflected a lower risk of asthma in adult populations and could be beneficial to asthma prevention regardless of genetic conditions. Early detection and management of sleep disorders could be beneficial to reduce asthma incidence.

Leptin and Asthma: What Are the Interactive Correlations?

Leptin is an adipokine directly correlated with the proinflammatory obese-associated phenotype. Leptin has been demonstrated to inhibit adipogenesis, promote fat demarcation, promote a chronic inflammatory state, increase insulin sensitivity, and promote angiogenesis. Leptin, a regulator of the immune response, is implicated in the pathology of asthma. Studies involved in the key cell reaction and animal models of asthma have provided vital insights into the proinflammatory role of leptin in asthma. Many studies described the immune cell and related cellular pathways activated by leptin, which are beneficial in asthma development and increasing exacerbations. Subsequent studies relating to animal models support the role of leptin in increasing inflammatory cell infiltration, airway hyperresponsiveness, and inflammatory responses. However, the conclusive effects of leptin in asthma are not well elaborated. In the present study, we explored the general functions and the clinical cohort study supporting the association between leptin and asthma. The main objective of our review is to address the knowns and unknowns of leptin on asthma. In this perspective, the arguments about the different faces of leptin in asthma are provided to picture the potential directions, thus yielding a better understanding of asthma development.

IL-33 receptor inhibition in subjects with uncontrolled asthma: A randomized, placebo-controlled trial

Background

Most biologics for severe asthma target only type 2 immunity. Inhibition of IL-33 signaling has the potential to target type 2 and non-type 2 pathways.

Objective

This multicenter phase IIA study evaluated the safety and efficacy of GSK3772847, a human mAb directed against the IL-33 receptor (IL-33R) in subjects with moderate-to-severe uncontrolled asthma.

Methods

Adults with uncontrolled asthma despite inhaled corticosteroid/long-acting β2-agonist therapy received equivalent replacement medication (open-label fluticasone propionate/salmeterol [500/50 μg, twice daily]) for 2 weeks before randomization at week 0. At weeks 0, 4, 8, and 12, participants were administered blinded placebo or 10 mg/kg of intravenous GSK3772847. At week 2, salmeterol was discontinued; thereafter, fluticasone propionate was titrated by approximately 50% on weeks 4, 6, 8, and 10. Asthma control was assessed until week 16. Participants with loss of asthma control discontinued treatment. The primary end point was loss of asthma control; secondary end points were the efficacy, safety, tolerability, pharmacodynamics, and pharmacokinetics of GSK3772847.

Results

At week 16, 56 participants (81%) and 45 (66%) receiving placebo and GSK3772847, respectively, had loss of asthma control (an 18% reduction [95% credible interval = 2%-35%]). Early loss of asthma control prevented full analysis of the secondary efficacy end points after week 4. The most frequent classes of treatment-related adverse events were cardiac disorders (n = 3 [4%] in both groups) and musculoskeletal/connective tissue disorders (with GSK3772847, n = 3 [4%]; with placebo n = 0). Target engagement of IL-33R by GSK3772847 was demonstrated.

Conclusion

Treatment with GSK3772847 may be beneficial for patients with uncontrolled asthma. Further studies are warranted.

Edible algae (Ecklonia cava) bioprocessed with mycelia of shiitake (Lentinula edodes) mushrooms in liquid culture and its isolated fractions protect mice against allergic asthma

BACKGROUND

Ecklonia cava is an edible marine brown alga harvested from the ocean that is widely consumed in Asian countries as a health-promoting medicinal food The objective of the present study is to evaluate the anti-asthma mechanism of a new functional food produced by bioprocessing edible algae Ecklonia cava and shiitake Lentinula edodes mushroom mycelia and isolated fractions.

METHODS

We used as series of methods, including high performance liquid chromatography, gas chromatography, cell assays, and an in vivo mouse assay to evaluate the asthma-inhibitory effect of Ecklonia cava bioprocessed (fermented) with Lentinula edodes shiitake mushroom mycelium and its isolated fractions in mast cells and in orally fed mice.

RESULTS

The treatments inhibited the degranulation of RBL-2H3 cells and immunoglobulin E (IgE) production, suggesting anti-asthma effects in vitro. The in vitro anti-asthma effects in cells were confirmed in mice following the induction of asthma by alumina and chicken egg ovalbumin (OVA). Oral administration of the bioprocessed Ecklonia cava and purified fractions suppressed the induction of asthma and was accompanied by the inhibition of inflammation- and immune-related substances, including eotaxin; thymic stromal lymphopoietin (TSLP); OVA-specific IgE; leukotriene C4 (LTC4); prostaglandin D2 (PGD2); and vascular cell adhesion molecule-1 (VCAM-1) in bronchoalveolar lavage fluid (BALF) and other fluids and organs. Th2 cytokines were reduced and Th1 cytokines were restored in serum, suggesting the asthma-induced inhibitory effect is regulated by the balance of the Th1/Th2 immune response. Serum levels of IL-10, a regulatory T cell (Treg) cytokine, were increased, further favoring reduced inflammation. Histology of lung tissues revealed that the treatment also reversed the thickening of the airway wall and the contraction and infiltration of bronchial and blood vessels and perialveolar inflammatory cells. The bioprocessed Ecklonia cava/mushroom mycelia new functional food showed the highest inhibition as compared with commercial algae and the fractions isolated from the bioprocessed product.

CONCLUSIONS

The in vitro cell and in vivo mouse assays demonstrate the potential value of the new bioprocessed formulation as an anti-inflammatory and anti-allergic combination of natural compounds against allergic asthma and might also ameliorate allergic manifestations of foods, drugs, and viral infections.