Impact of obesity in asthma: Possible future therapies.

Obesity is one of the factors associated with the severity of asthma. Obesity is associated with aggravation of the pathophysiology of asthma, including exacerbations, airway inflammation, decreased pulmonary function, and airway hyperresponsiveness. The present review addresses the characteristics of asthma with obesity, focusing especially on the heterogeneity caused by the degree of type 2 inflammation, sex differences, the onset of asthma, and race differences. To understand the severity mechanisms in asthma and obesity, such as corticosteroid resistance, fatty acids, gut microbiome, and cytokines, several basic research studies are evaluated. Finally, possible future therapies, including weight reduction, microbiome-targeted therapies, and other molecular targeted therapies are addressed. We believe that the present review will contribute to better understanding of the severity mechanisms and the establishment of novel treatments for severe asthma patients with obesity.

Thymic stromal lymphopoietin contributes to ozone-induced exacerbations of eosinophilic airway inflammation via granulocyte colony-stimulating factor in mice.

BACKGROUND: Ozone is one of the triggers of asthma, but its impact on the pathophysiology of asthma, such as via airway inflammation and airway hyperresponsiveness (AHR), is not fully understood. Thymic stromal lymphopoietin (TSLP) is increasingly seen as a crucial molecule associated with asthma severity, such as corticosteroid resistance. METHODS: Female BALB/c mice sensitized and challenged with house dust mite (HDM) were exposed to ozone at 2 ppm for 3 h. Airway inflammation was assessed by the presence of inflammatory cells in bronchoalveolar lavage fluid and concentrations of cytokines including TSLP in lung. Anti-TSLP antibody was administered to mice to block the signal. Survival and adhesion of bone marrow-derived eosinophils in response to granulocyte colony-stimulating factor (G-CSF) were evaluated. RESULTS: Ozone exposure increased eosinophilic airway inflammation and AHR in mice sensitized and challenged with HDM. In addition, TSLP, but not IL-33 and IL-25, was increased in lung by ozone exposure. To confirm whether TSLP signaling is associated with airway responses to ozone, an anti-TSLP antibody was administered, and it significantly attenuated eosinophilic airway inflammation, but not AHR. Interestingly, G-CSF, but not type 2 cytokines such as IL-4, IL-5, and IL-13, was regulated by TSLP signaling associated with eosinophilic airway inflammation, and G-CSF prolonged survival and activated eosinophil adhesion. CONCLUSIONS: The present data show that TSLP contributes to ozone-induced exacerbations of eosinophilic airway inflammation and provide greater understanding of ozone-induced severity mechanisms in the pathophysiology of asthma related to TSLP and G-CSF.

[THE EFFICACY OF BRONCHIAL THERMOPLASTY IN LONG-TERM MAINTENANCE OF ADULT PATIENTS WITH MODERATE TO SEVERE ASTHMA].

BACKGROUND AND AIMS: Bronchial thermoplasty (BT) is a bronchoscopic treatment for adult patients with moderate to severe asthma. A systematic review was conducted to examine the efficacy of this treatment. METHODS: Randomized controlled comparing BT to a control in adult patients with moderate to severe asthma were added to the previously conducted systematic review. Literature published prior to July 2022 was selected. RESULTS: Four trials were included in this study. BT resulted in significant improvement in quality of life. However, no significant difference in asthma control was observed. Moreover, the incidence of severe adverse events during the treatment period was increased by BT. Furthermore, BT did not improve lung function, increase withdrawal from oral corticosteroids, reduce frequency of rescue medication usage, or increase the number of symptom-free days. CONCLUSION: From a risk-benefit perspective, there is insufficient evidence to support a recommendation of BT in adult patients with moderate to severe asthma.

[RECURRENT AND VIRTUAL EDUCATION FOR ALL DISCIPLINES AND OCCUPATIONS IN THE ALLERGY REALM : A SURVEY OF THE PARTICIPANTS FROM THE INITIATIVE 'OUTREACH LECTURES' TO CREATE EDUCATIONAL OPPORTUNITIES].

BACKGROUND: In the enhancement of allergy care involving multidisciplinary and multiple medical departments, there is a perceived need for education that targets not only specialists but also non-specialists. However, research on the need for and methods of such education remains inadequate. OBJECTIVE: To design a remote allergy care education program for all medical practitioners and to validate its necessity and utility. METHODS: The Empowering Next Generation Allergist/immunologist toward Global Excellence Task Force (ENGAGE-TF), supported by the Japanese Society of Allergology, initiated a virtual educational program called 'Outreach Lectures' in collaboration with Keio University and Fukui University. This initiative was widely promoted through social media and various institutions, and a survey was conducted through its mailing list. RESULTS: 1139 responses were obtained. More than half were physicians from non-allergy specialties, representing a diverse range of healthcare professions. Over 70% expressed being 'very satisfied,' and over 60% found the difficulty level 'appropriate.' Free-form feedback revealed differences in learning focus based on profession and learning approach based on years of experience. CONCLUSION: The high participation rate (90%) of non-specialist physicians underscores the demand for addressing allergic conditions in primary care. The effectiveness of virtual / recurrent education, particularly for healthcare professionals with over 11 years of experience, was implied. Further follow-up investigation focusing on quantitative and objective assessment of educational effectiveness is indispensable.

Effect of health locus of control on physical activity in stable patients with chronic obstructive pulmonary diseases.

[Purpose] A strong correlation exists between low physical activity and the prognosis of patients with chronic obstructive pulmonary disease (COPD). The interaction between psychological factors and low physical activity remains unclear in patients with COPD. Here, we investigated the impact of the health locus of control (HLOC) on the response to an education program in patients with COPD. [Participants and Methods] We assessed the physical activities and HLOC in participants with COPD before and after a five-month education program. We assessed physical activity using the Japanese version of the International Physical Activity Questionnaire (IPAQ). We evaluated the HLOC using the Japanese version of the HLOC scales. We provided an identical educational program to all participants after the initial evaluation. [Results] The total activity and walking scores were significantly elevated after the intervention. We observed a significant negative correlation between the IPAQ Total score after the intervention and the supernatural HLOC. We also observed significant negative correlations between the IPAQ Vigorous score after the intervention and Family HLOC and Chance HLOC. [Conclusion] The response of patients with COPD to self-care educational programs was influenced by the HLOC.

The Nonantibiotic Macrolide EM900 Attenuates House Dust Mite-Induced Airway Inflammation in a Mouse Model of Obesity-Associated Asthma.

INTRODUCTION: Obesity-associated asthma is characterized by type 2-low airway inflammation. We previously showed that EM900, which is a 12-membered nonantibiotic macrolide, suppressed airway inflammation in a mouse model of asthma exacerbation. The aim of this study was to clarify the effects of EM900 in obesity-associated asthma. METHODS: BALB/c mice were fed a low-fat diet (LFD) or high-fat diet (HFD). Mice were intranasally sensitized and challenged with house dust mites (HDMs) and were orally administered EM900. Airway inflammation was assessed using inflammatory cells in bronchoalveolar lavage (BALF). Cytokines were examined by ELISA in lung tissues. Lung interstitial macrophages (CD45+, CD11clow, CD11b+, and Ly6c-) were counted by flow cytometry in single cells from lung tissues. RESULTS: Body weight increased significantly in the HFD compared with the LFD group. The total cell count and numbers of neutrophils and eosinophils in BALF were significantly suppressed by EM900 administration in the HFD-HDM group. The levels of interleukin (IL)-17A were increased in the HFD-HDM group compared with the LFD-HDM group, although the difference did not reach statistical significance. The levels of IL-17A, macrophage inflammatory protein 2, IL-1ß, IL-5, and regulated on activation, normal T cell expressed and secreted in lung tissue were significantly suppressed by EM900 administration in the HFD-HDM group. The percentage of interstitial macrophages in lungs was significantly decreased by EM900 administration in the HFD-HDM group. CONCLUSION: Both type 2 and type 2-low airway inflammation were attenuated by EM900 in this obesity-associated asthma model. These results show that EM900 might be a candidate agent for the treatment of obesity-associated asthma.

The non-antibiotic macrolide EM900 attenuates HDM and poly(I:C)-induced airway inflammation with inhibition of macrophages in a mouse model.

OBJECTIVE: Macrolides have been reported to reduce the exacerbation of severe asthma. The aim of this study was to clarify the effects and mechanisms of EM900, a non-antibiotic macrolide, on allergic airway inflammation. METHODS: Mice were sensitized and challenged by house dust mite (HDM), then exposed to polyinosinic-polycytidylic acid (poly(I:C)) as a model of asthma complicated with viral infection. Mice were administered with EM900. Airway inflammation was assessed from inflammatory cells in bronchoalveolar lavage fluid (BALF) and cytokines in lung tissues. Lung interstitial macrophages were counted by flow cytometry. Cytokine production, phosphorylation of NF-κB, and p38 in macrophages were examined by ELISA and western blotting. RESULTS: Counts of cells in BALF and concentrations of IL-13, IL-5, RANTES, IL-17A, and MIP-2 were significantly decreased by EM900 compared to those without EM900. Percentages of lung interstitial macrophages were significantly decreased with EM900. Concentrations of IL-6, RANTES, and MIP-2 induced by HDM and poly(I:C) were significantly suppressed by EM900 through the suppression of NF-κB and p38 phosphorylation in macrophages. CONCLUSIONS: HDM and poly(I:C)-induced airway inflammation is attenuated by EM900 with the inhibition of lung interstitial macrophages. Clinical use of EM900 is expected, because EM900 has inhibitory effects against airway inflammation without inducing bacterial drug resistance.

A rare case of Trichosporon mycotoxinivorans and Cryptococcus neoformans co-infection in lung.

A 70-year-old woman with liver cirrhosis caused by primary biliary cirrhosis and rheumatoid arthritis was found to have multiple pulmonary nodular shadows in the right middle and lower lung fields on chest radiography. The multiple pulmonary nodules and masses rapidly increased over 2 months. Trichosporon mycotoxinivorans and Cryptococcus neoformans were identified in brushing specimens, bronchial lavage, and transbronchial lung biopsy specimens. The patient was diagnosed as having a co-infection of the lung with T. mycotoxinivorans and C. neoformans, and was treated with fluconazole. Although the pulmonary shadows were under control with treatment, she died 5 months later due to liver failure. We report herein a rare case of co-infection of the lung with T. mycotoxinivorans and C. neoformans.

Clinical features of Japanese patients with exacerbations of chronic obstructive pulmonary disease.

BACKGROUND: Exacerbations are critical events in chronic pulmonary obstructive disease (COPD). The frequency of COPD exacerbations is associated with the prognosis, including mortality, but no useful biomarker has been established. METHODS: The present retrospective study investigated 481 COPD patients. Clinical features in the stable period were compared between patients who experienced severe exacerbation (n = 88, 18.3%) and those who never experienced severe exacerbation (n = 393, 81.7%). In the patients who experienced exacerbations, clinical features were also compared between frequent exacerbators (exacerbation rate ≥ 2 times/year, n = 27, 30.7%) and infrequent exacerbators (1 time/year, n = 61, 69.3%). RESULTS: Compared to COPD patients who never experienced exacerbations, body mass index (BMI), serum albumin, and pulmonary functions were significantly lower, and the cardiovascular disease comorbidity rate, COPD assessment test score, modified Medical Research Council dyspnea scale, and use of long-term oxygen therapy, long-acting ß2 adrenergic agonist therapy, inhaled corticosteroid therapy, and macrolide therapy were significantly higher in COPD patients with exacerbations (all p < 0.01). In patients who experienced exacerbations, frequent exacerbators had significantly lower % forced expiratory volume in 1.0 s and a higher risk of critical exacerbations, percentage of blood eosinophils, history of mechanical ventilation use, and use of long-term oxygen therapy and of macrolide therapy than infrequent exacerbators (all p < 0.01). On multivariate analysis, the percentage of blood eosinophils was the parameter most correlated with exacerbation frequency (ß value [95% confidence interval] 1.45 [1.12-1.88], p < 0.01). CONCLUSION: Blood eosinophil in the stable period is the factor most correlated with the frequency of severe exacerbations. TRIAL REGISTRATION: The patients in this study was registered retrospectively.

Clinical impact of advanced chronic kidney disease in patients with non-HIV pulmonary cryptococcosis.

BACKGROUND: Pulmonary cryptococcosis is an uncommon infectious disease that can develop in both immunocompromised and immunocompetent patients. The severity of chronic kidney disease (CKD) was reported to be one of the risk factors for pulmonary cryptococcosis, but its clinical characteristics have not been fully assessed. The purpose of this study was to clarify the clinical characteristics of advanced CKD in patients with pulmonary cryptococcosis. METHODS: The present study retrospectively investigated 56 patients who had non-human immunodeficiency virus (HIV) pulmonary cryptococcosis and were treated at Saga University Hospital between 2005 and 2018. The clinical characteristics were evaluated and compared between patients with estimated glomerular filtration rate (eGFR) > 45 mL/min/1.73 m2 (n = 42, early CKD) and those with eGFR < 45 mL/min/1.73 m2 (n = 14, advanced CKD. RESULTS: Compared with patients with early CKD, those with advanced CKD had significantly higher rate of disseminated cryptococcosis (21.4% vs. 2.4%, p = 0.03); lower percentage of patients who recovered after treatment (63.6% vs. 92.5%, p = 0.02); and more frequent clinical features of fever (57.1% vs. 19.0%, p < 0.01), pleural effusion (21.4% vs. 2.4%, p = 0.03), high white blood cell count (8550/mL vs. 6150/mL, p = 0.01) and C-reactive protein (CRP) (2.1 mg/dL vs. 0.2 mg/dL, p = 0.02), and low level of serum albumin (3.0 g/dL vs. 3.8 g/dL, p < 0.01). Multivariate analysis adjusted by immunosuppressive drug use indicated the significant factors of fever (odds ratio or ß value [95% confidence interval] 6.4 [1.65-20.09], p < 0.01), high white blood cell count (1293.2 [110.2-2476.2], p = 0.03), C-reactive protein (0.89 [0.18-1.59], p = 0.01) and low level of serum albumin (- 0.34 [- 0.54 - - 0.14], p < 0.01) in patients with eGFR < 45 mL/min/1.73m2. CONCLUSION: Advanced CKD was associated with poor clinical characteristics and outcomes in patients with non-HIV pulmonary cryptococcosis. TRIAL REGISTRATION: The patients in this study were registered retrospectively.

Adherence barriers to inhaled medicines in Japanese older patients with asthma evaluated using the "Adherence Starts with Knowledge 20" (ASK-20) questionnaire.

OBJECTIVE: We investigated adherence barriers to inhaled medicines among older compared to younger adults with asthma in Japan. METHODS: Adherence barriers to inhaled medicines were evaluated in 251 Japanese older (n = 138) and younger (n = 113) adults with asthma using the self-reporting "Adherence Starts with Knowledge 20" (ASK-20) questionnaire. RESULTS: There were fewer older adults with poor adherence to inhaled medicines than younger adults. The ASK-20 questionnaire revealed (odds ratio [95% confidence interval]) item Q11 ("My doctor/nurse and I work together to make decisions"; 2.94 [1.31, 6.61]; p < 0.05) as an independent adherence barrier to inhaled medicines among older adults, whereas younger adults reported item Q3 ("My use of alcohol gets in the way of taking my medicines"; 3.91 [1.02 to 15.1]; p < 0.05) and item Q16 ("Taken a medicine more or less often than prescribed? "; 2.31 [1.32 to 4.06]; p < 0.05) as barriers. Older adults with poor adherence identified item Q1 ("I just forget to take my inhaled medicines some of the time"; 4.43 [1.77, 11.1]; p < 0.05) as a barrier, although the total ASK-20 scores and total barrier counts were significantly higher in older (both, p < 0.05) and younger (both, p < 0.05) adults with poor adherence than in those with good adherence. CONCLUSION: Older Japanese patients had better adherence to inhaled medicines than younger patients. Barriers were different between older and younger adults. These results will help personalize education for inhaled medicines in Japanese asthmatics.

Lipopeptides are signaled by Toll-like receptor 1, 2 and 6 in endolysosomes.

Toll-like receptors (TLRs) recognize a variety of microbial products and induce defense responses. Pathogen sensing by TLRs occurs either on the cell surface or in endolysosomes. TLR-dependent responses are greatly influenced by the site of pathogen sensing. TLR heterodimers TLR1/TLR2 and TLR2/TLR6 recognize tri- or diacylated microbial lipopeptides, respectively. Although TLR1, 2 and 6 are believed to localize on the cell surface of immune cells, little is known about where lipopeptides are signaled. In this study, we established mAbs to TLR1, 2 and 6. TLR1, 2 and 6 were expressed on the surface of B cells, monocytes and dendritic cells in a manner dependent on a TLR-specific chaperone PRAT4A (protein associated with TLR4 A). Cell surface localization of TLR1 or TLR6 was not necessarily required for TLR2 response. Furthermore, a dynamin inhibitor 'Dynasore' abolished the lipopeptide responses by preventing lipopeptide internalization into LAMP-1 and LAMP-2 positive compartments. Our findings suggest that lipopeptides elicit TLR1/2 and TLR2/6 signaling in the endolysosomes, but not on the cell surface.

ß2 adrenergic agonist attenuates house dust mite-induced allergic airway inflammation through dendritic cells.

BACKGROUND: Long-acting ß2 adrenergic agonists (LABAs) are commonly used combined with inhaled corticosteroids (ICS) to treat asthmatic patients. Previous reports suggest that LABAs have an anti-inflammatory effect in bronchial asthma, and this should be further investigated. The aim of this study was to investigate whether LABAs inhibit allergic airway inflammation and how this occurs. RESULTS: We assessed the effect of the LABA formoterol (FORM) on inflammatory cell responses in airway, lung and regional lymph nodes, using an HDM-induced murine allergic asthma model in vivo. The effect of FORM on cytokine production from bone marrow derived dendritic cells (BMDCs) stimulated with HDM was evaluated in vitro. Adoptive transfer of BMDCs pulsed with HDM in the presence or absence of FORM to naïve mice was performed and the inflammatory response to subsequent HDM challenge was analyzed. FORM treatment suppressed HDM-induced changes and caused an increase in the number of eosinophils and neutrophils in bronchoalveolar lavage. The concentration of IL-4 and IL-17 in lung tissue homogenate was elevated and led to an accumulation of IL-4, IL-13, IL-5 and IL-17 producing cells in regional lymph nodes. FORM inhibited the production of IL-6 and IL-23 from BMDCs stimulated with HDM in vitro, and enhanced IL-10 production. The BMDCs adoptive transfer experiment indicated that dendritic cells mediate the effect of FORM, since FORM treatment of BMDCs in vitro attenuated airway inflammation. CONCLUSION: These results suggested that FORM modulates dendritic cell function and attenuates Th2 and Th17 responses induced by HDM. Thus, we propose that the clinical significance of LABAs should be re-investigated taking into account these immune-modulating effects.

Human TLR4 polymorphism D299G/T399I alters TLR4/MD-2 conformation and response to a weak ligand monophosphoryl lipid A.

A cell surface heterodimer Toll-like receptor 4 (TLR4)/MD-2 senses lipopolysaccharide (LPS), a principal membrane component of Gram-negative bacteria. LPS binds to MD-2 and induces dimerization of TLR4/MD-2. Dimerized TLR4 activates downstream signaling. TLR4 polymorphism replacing Asp299 with Gly and Thr399 with Ile (D299G/T399I) causes LPS hyporesponsiveness, and is associated with a variety of infectious and noninfectious diseases. However, a molecular mechanism underlying the LPS hyporesponsiveness remains controversial. We here asked whether the TLR4 polymorphism influenced cell surface expression of TLR4/MD-2, ligand-dependent TLR4/MD-2 dimerization or TLR4/MD-2 responses to a weak agonist monophosphoryl lipid A (MPL). A newly established anti-TLR4 mAb detected D299G/T399I TLR4/MD-2 on Ba/F3 cells, whereas a previous anti-TLR4 mAb did will this fit on the line above?, suggesting that the D299G/T399I polymorphism caused a conformational change in TLR4. Hyporesponsiveness of D299G/T399I TLR4/MD-2 was much more apparent when cells were stimulated with MPL than with lipid A. MPL-dependent TLR4/MD-2 dimerization was impaired by the D299G/T399I polymorphism. The D299G/T399I polymorphism did not alter LPS-binding to soluble TLR4/MD-2, but impaired its dimerization. These results suggest that the D299G/T399I TLR4 polymorphism impairs TLR4/MD-2 responses by altering ligand-dependent dimerization.

Clinical Impacts of Interventions for Physical Activity and Sedentary Behavior on Patients with Chronic Obstructive Pulmonary Disease.

Recently, physical activity has increasingly become the focus in patients with chronic obstructive airway disease (COPD) because it is a strong predictor of COPD-related mortality. In addition, sedentary behavior, which is included as a category of physical inactivity including such behaviors as sitting or lying down, has an independent clinical impact on COPD patients. The present review examines clinical data related to physical activity, focusing on the definition, associated factors, beneficial effects, and biological mechanisms in patients with COPD and with respect to human health regardless of COPD. The data related to how sedentary behavior is associated with human health and COPD outcomes are also examined. Lastly, possible interventions to improve physical activity or sedentary behavior, such as bronchodilators and pulmonary rehabilitation with behavior modification, to ameliorate the pathophysiology of COPD patients are described. A better understanding of the clinical impact of physical activity or sedentary behavior may lead to the planning of a future intervention study to establish high-level evidence.

A 45-Year-Old Woman With Unexplained Iron Deficiency Anemia and No Respiratory Symptoms.

CASE PRESENTATION: A 45-year-old Japanese woman was diagnosed with anemia in a work place medical check-up and came to our hospital for further investigations. She had experienced general fatigue and orthostatic dizziness for 6 months without fever or respiratory symptoms, including cough, sputum, hemoptysis, or dyspnea. She had undergone annual medical check-ups previously, which had shown no abnormalities, including anemia. She had no history of weight loss, epimenorrhagia, hematuria, or melena. She had no significant positive medical history and was not on any regular medication or supplements. She had no history of alcohol abuse or smoking.

Pleural lymphoma combined with pleural sarcoidosis.

A patient with sarcoidosis was found to have a massive left pleural effusion. Her chest computed tomography showed small nodules in the lung parenchyma and swelling of the hilar lymph nodes, with normal visceral and parietal pleura. Thoracoscopy showed white nodules on the visceral pleura and normal parietal pleura, which were resected. Epithelioid granulomas were seen in the visceral pleura and lung parenchyma. Surprisingly, in the parietal pleura, abnormal cells that were positive for the leukocyte common antigen, CD20, and CD79a were found, leading to the diagnosis of malignant B-cell lymphoma.

Efficacy and safety of once-daily single-inhaler triple therapy for mild-to-moderate chronic obstructive pulmonary disease: a study protocol for a randomised and interventional study.

INTRODUCTION: Bronchodilators, including long-acting muscarinic antagonists (LAMA) and long-acting beta 2 agonists (LABA), are the main treatments for chronic obstructive pulmonary disease (COPD). The efficacy of triple therapy (inhaled corticosteroids/LAMA/LABA) has also been reported. However, the effect of triple therapy on patients with mild-to-moderate COPD has not yet been clarified. This study aims to investigate the safety and efficacy of triple therapy, compared with LAMA/LABA combination therapy, for lung function and health-related quality of life in patients with mild-to-moderate COPD and identify baseline characteristics and biomarkers to predict responders and non-responders to triple therapy. METHODS AND ANALYSIS: This is a multicentre, prospective, open-label, randomised, parallel-group study. Mild-to-moderate patients with COPD will be randomised to receive fluticasone furoate/umeclidinium/vilanterol or umeclidinium/vilanterol for 24 weeks. A total of 668 patients will be enrolled from March 2022 to September 2023 from 38 sites in Japan. The primary endpoint is the change in the trough forced expiration volume in 1 s after 12 weeks of treatment. Secondary endpoints are responder rates based on the COPD assessment test score and the St. George's Respiratory Questionnaire total score after 24 weeks of treatment. The safety endpoint is the occurrence of any adverse events. We will also investigate safety in terms of changes in microbial colonisation in sputum and antimycobacterium avium complex antibodies. ETHICS AND DISSEMINATION: The study protocol and informed consent documents were approved by the Saga University Clinical Research Review Board (approval number: CRB7180010). Written informed consent will be obtained from all patients. Recruitment of the patients began in March 2022. The results will be disseminated through scientific peer-reviewed publications and domestic and international medical conferences. TRIAL REGISTRATION NUMBERS: UMIN000046812 and jRCTs031190008.

Effect of Azithromycin on Exacerbations in Asthma Patients with Obesity: Protocol for a Multi-Center, Prospective, Single-Arm Intervention Study.

INTRODUCTION: Obesity is associated with severe asthma, but no specific treatment has been established. The gut microbiome is increasingly recognized as a crucial factor, but specific treatments focused on the gut microbiome have not been established. Recently, azithromycin has been found to have the capacity to attenuate exacerbations, a characteristic of severe asthma. The effect of azithromycin on obesity-induced severe asthma is not understood. METHODS: The purpose of the present study is to clarify the effect of azithromycin on exacerbations in asthmatic patients with obesity. To explore the mechanism, the gut microbiome, metabolites of microbes such as short-chain fatty acids, and blood inflammatory cytokines will be analyzed to evaluate the correlation with the effect of azithromycin on exacerbations in obesity-induced severe asthma. A multi-center, prospective, single-arm intervention study is planned. DISCUSSION: The present study will allow us to evaluate the effect of azithromycin on exacerbations, particularly in asthma patients with obesity, and explore biomarkers, targeting molecules including the gut microbiome, which are correlated with decreased exacerbations. The present results could contribute to identifying new therapeutic prospects and targeted microbes or molecules associated with severe clinical characteristics in asthmatic patients with obesity. TRIAL REGISTRATION: This study has been registered as a prospective study with the University Hospital Medical Information Network (UMIN0000484389) and the Japan Registry of Clinical Trials (jRCTs071220023).