Real-world safety and effectiveness of mepolizumab for patients with eosinophilic granulomatosis with polyangiitis in Japan: A 48-week interim analysis of the MARS study.

OBJECTIVES: The objective of the study is to assess real-world, long-term safety/effectiveness of mepolizumab for eosinophilic granulomatosis with polyangiitis (EGPA) in Japan. METHODS: The Mepolizumab long-term study to Assess Real-world Safety and effectiveness of EGPA in Japan (MARS) (GSK ID: 213684/NCT04551989) is an ongoing 96-week study of patients with EGPA who received four-weekly mepolizumab 300 mg subcutaneously for ≥96 weeks before study entry (baseline) and continued treatment. This interim analysis included safety from baseline to Week 48 (observation period) and clinical outcomes before mepolizumab and during the observation period. RESULTS: Of 118 patients enrolled, 29% (34/118) experienced adverse events (AEs), of which 13% (15/118) experienced serious AEs; none were considered mepolizumab related. The median oral corticosteroid (OCS) dose decreased from 6.9 (pre-mepolizumab) to 3.0 (baseline) and 2.0 mg/day (Weeks 45-48); the proportion of patients receiving no OCS increased from 8% to 32% and 38%, respectively. Patients experiencing clinical symptoms decreased from 94% (pre-mepolizumab) to 73% (baseline) and 67% (Week 48). During the observation period, 5% of patients experienced EGPA relapse; the rates of EGPA-related hospitalisations, EGPA-related emergency room/unscheduled visits, and asthma exacerbations were 0.05, 0.09, and 0.08 event/person-year, respectively. CONCLUSIONS: The results of mepolizumab treatment for ≥144 weeks (before baseline plus observation) were consistent with the known safety profile and allowed OCS dose reduction while improving disease control versus pre-treatment among patients with EGPA.

Direct platelet adhesion potentiates group 2 innate lymphoid cell functions.

BACKGROUND: Platelets are thought to be involved in the pathophysiology of asthma, presumably through direct adhesion to inflammatory cells, including group 2 innate lymphoid cells (ILC2s). Here, we tried to elucidate the effects of platelet adhesion to ILC2s in vitro and in vivo, as well as the mechanisms involved. METHODS: Alternaria-induced ILC2-dependent airway inflammation models using wild-type and c-mpl-/- mice were evaluated. Both purified CD41+ and CD41- ILC2s were cultured with IL-2 and IL-33 to determine in vitro Type 2 (T2) cytokine production and cell proliferation. RNA-seq data of flow-cytometry-sorted CD41+ and CD41- ILC2s were used to isolate ILC2-specific genes. Flow cytometry was performed to determine the expression of CD41 and adhesion-related molecules on ILC2s in both mouse and human tissues. RESULTS: T2 inflammation and T2 cytokine production from ILC2s were significantly reduced in the c-mpl-/- mice compared to wild-type mice. Platelet-adherent ILC2s underwent significant proliferation and showed enhanced T2 cytokine production when exposed to IL-2 and IL-33. The functions of ILC2-specific genes were related to cell development and function. Upstream regulator analysis identified 15 molecules, that are thought to be involved in ILC2 activation. CD41 expression levels were higher in ILC2s from human PBMCs and mouse lung than in those from secondary lymphoid tissues, but they did not correlate with the P-selectin glycoprotein ligand-1 or CD24 expression level. CONCLUSION: Platelets spontaneously adhere to ILC2s, probably in the peripheral blood and airways, thereby potentiating ILC2s to enhance their responses to IL-33.

Reduction in asthma exacerbation rate after mepolizumab treatment initiation in patients with severe asthma: A real-world database study in Japan.

OBJECTIVE: To investigate the changes in asthma exacerbation, as well as in oral corticosteroid (OCS) use, exacerbation-related healthcare resource utilization (HRU), and healthcare costs before and after mepolizumab treatment initiation in patients with severe asthma who started treatment with mepolizumab in a real-world clinical setting in Japan. METHODS: A retrospective, observational, self-controlled study was conducted in Japan using a hospital-based administrative claims database. Patients who were diagnosed with asthma and who were new users of mepolizumab were included in the study. The primary outcome was the incidence rate of any asthma exacerbation/patient-year during the 12-month period before (baseline period) and after (follow-up period) the first mepolizumab prescription. Secondary outcome measures included the proportion of patients with ≥1 any asthma exacerbation, patients with exacerbation requiring hospitalization, the incidence rate of exacerbations requiring hospitalization/patient-year, the median daily OCS dose (OCS sparing effect), exacerbation-related HRU (hospitalization length, the proportion of patients with emergency visits, and the number of emergency/outpatient visits), and associated costs. RESULTS: Of the 377 patients included, 56.2% were ≥65 years of age. Following the first mepolizumab prescription, incidence rates for any asthma exacerbation were reduced by 40.6% (4.00/patient-year to 2.38/patient-year; the incidence rate ratio [95% confidence interval]: 0.60 [0.53-0.67]; p < 0.0001) from the baseline to follow-up periods. The incidence rate of exacerbations requiring hospitalization was reduced by 55.8% (0.37/patient-year to 0.16/patient-year) from the baseline to follow-up periods. The proportion of patients experiencing any exacerbation decreased from 84.4% to 57.8% and those requiring hospitalization decreased from 23.9% to 10.3% both from the baseline to follow-up periods. The median daily OCS dose decreased by 44.6% (median [interquartile range]: 6.7 [4.7-9.9] mg/day to 3.3 [0.9-5.6] mg/day) from the last baseline quarter to the 4th quarter of the follow-up period. All exacerbation-related HRUs decreased from the baseline to follow-up periods. Inpatient cost reduced by >50% (123,279 Japanese Yen [JPY]/patient-year vs. 57,283 JPY/patient-year), reducing the total cost by 80,716 JPY from the baseline to follow-up periods. CONCLUSION: Mepolizumab was effective in treating patients with severe asthma by reducing the incidence rates of exacerbations and exacerbation requiring hospitalization, OCS dose, exacerbation-related HRU, and cost in routine clinical practice in Japan.

Japanese guidelines for adult asthma 2020.

Bronchial asthma is characterized by chronic airway inflammation, which manifests clinically as variable airway narrowing (wheezes and dyspnea) and cough. Long-standing asthma may induce airway remodeling and become intractable. The prevalence of asthma has increased; however, the number of patients who die from it has decreased (1.3 per 100,000 patients in 2018). The goal of asthma treatment is to control symptoms and prevent future risks. A good partnership between physicians and patients is indispensable for effective treatment. Long-term management with therapeutic agents and the elimination of the triggers and risk factors of asthma are fundamental to its treatment. Asthma is managed by four steps of pharmacotherapy, ranging from mild to intensive treatments, depending on the severity of disease; each step includes an appropriate daily dose of an inhaled corticosteroid, which may vary from low to high. Long-acting ß2-agonists, leukotriene receptor antagonists, sustained-release theophylline, and long-acting muscarinic antagonists are recommended as add-on drugs, while anti-immunoglobulin E antibodies and other biologics, and oral steroids are reserved for very severe and persistent asthma related to allergic reactions. Bronchial thermoplasty has recently been developed for severe, persistent asthma, but its long-term efficacy is not known. Inhaled ß2-agonists, aminophylline, corticosteroids, adrenaline, oxygen therapy, and other approaches are used as needed during acute exacerbations, by selecting treatment steps for asthma based on the severity of the exacerbations. Allergic rhinitis, eosinophilic chronic rhinosinusitis, eosinophilic otitis, chronic obstructive pulmonary disease, aspirin-exacerbated respiratory disease, and pregnancy are also important conditions to be considered in asthma therapy.

Comparison of tumor cell numbers and 22C3 PD-L1 expression between cryobiopsy and transbronchial biopsy with endobronchial ultrasonography-guide sheath for lung cancer.

BACKGROUND: We previously reported cryobiopsy (Cryo) with endobronchial ultrasonography-guide sheath (EBUS-GS) for peripheral pulmonary lesions (PPLs) provides significantly larger tissues than transbronchial biopsy (TBB) and provides high quantity and quality DNA for gene analysis by next generation sequencing. However, the tumor cell yields and programmed death ligand 1 (PD-L1) expression between each approach have not been compared. Here, we assessed the tumor cell numbers and PD-L1 expression for Cryo with EBUS-GS for PPLs and TBB in patients with lung cancer. METHODS: Sixteen patients were enrolled in this prospective study from June to November 2017 at Tokyo Women's Medical University Hospital. The number of tumor cells from a single biopsy, total number of tumor cells, average number of tumor cells, and 22C3 PD-L1 expression (≥ 50% and ≥ 1%) were compared between Cryo and TBB. RESULTS: The numbers of tumor cells from a single biopsy, total numbers of tumor cells, and average numbers of tumor cells obtained by Cryo were significantly larger than those obtained by TBB (Cryo [means ± standard errors of the means]: 1321 ± 303.7, 1981 ± 411.7, and 1406 ± 310.3; TBB: 208.8 ± 38.24, 1044 ± 189.0, and 208.8 ± 37.81; P < 0.0001, P = 0.0474, P = 0.0006, respectively). PD-L1 ≥ 50% and ≥ 1% patients for Cryo were 18.8 and 56.3%, respectively, whereas those for TBB were 12.5 and 37.5%, respectively. The sensitivity, specificity, positive predictive value, negative predictive value, concordance, and κ coefficient based on Cryo for TBB were 66.7, 100, 100, 92.9, 93.8%, and 0.7647, respectively, for PD-L1 ≥ 50%; and 44.4, 71.4, 66.7, 50, 56.3%, and 0.1515, respectively, for PD-L1 ≥ 1%. CONCLUSION: Cryo with EBUS-GS may be a useful diagnostic approach for lung cancer, with advantages over TBB for gene analysis and whole exon sequencing. Particularly, it could contribute to patients taking pembrolizumab as first-line therapy when PD-L1 was negative by evaluating TBB specimens. It could also provide ample tissue for PD-L1 expression analysis in addition to accurate diagnosis and gene analysis.

Activating prostaglandin E2 receptor subtype EP4 increases secreted mucin from airway goblet cells.

Prostaglandin E2 (PGE2) is a ligand of the E-type prostanoid receptors, EP1-4. PGE2 secretion is increased in the airways of patients with asthma by secretory phospholipases A2, which also increases MUC5AC mucin in goblet cells. We hypothesized that PGE2 would also increase MUC5AC mRNA and secreted protein through specific EP receptor activation. We sought to assess the effect of specific EP receptor activation on MUC5AC secretion from ciliated-enriched cells or goblet-enriched cells induced by IL-13. We develop an enriched goblet cell epithelium by growing normal human bronchial epithelial cells at air liquid interface for 14 days in the presence of IL-13. We examined exposure to 4 specific EP receptor agonists at 24 h and 14 days in cells grown with or without IL-13 exposure, and measured MUC5AC mRNA and secreted protein, as well as airway culture morphology, and EP receptor expression. In ciliated-enriched cells grown in the absence of IL-13, the EP4 receptor agonist modestly increased both MUC5AC mRNA and secretion (p < 0.001, 241% increase of transcripts and p < 0.01, 86% increase of secreted protein) but did not visibly change cell morphology. In goblet-enriched cells grown in the presence of IL-13, the EP4 receptor agonist greatly increased both MUC5AC mRNA and protein (p < 0.001, 315% increase of transcripts and 92% increase of secreted protein). Specific activation of the other EP receptor had no effect on secreted mucin. EP4 receptor mRNA and protein were significantly increased in goblet-enriched cells, while the other receptor mRNA were decreased. We conclude that PGE2 stimulates airway mucin production predominantly by EP4 receptor activation in association with increased EP4 receptor expression. This may contribute to mucus hypersecretion as seen in severe asthma.

Therapeutic approaches of asthma and COPD overlap.

Asthma and COPD overlap (ACO) is an important clinical phenotype, due to the low-health-related quality of life (QOL), rapid decline in lung function, frequent exacerbation, and high economic burden. However, no large-scaled therapeutic trials of ACO have been conducted. At present, ACO is treated according to asthma/COPD guidelines. The goals of ACO treatment are to relieve symptoms and improve QOL and lung functions. Treatment must also prevent disease progression, airway remodeling, exacerbation, complications, and comorbidities. To achieve these goals, ACO needs first to be assessed based on pathophysiological findings. Comprehensive long-term management includes medication, reduction of risk factors, environmental improvement, patient education, rehabilitation, and vaccination. Drug treatment for ACO employs a combination of inhaled corticosteroids (ICSs) and long-acting bronchodilators; long-acting muscarinic antagonists and/or long-acting ß2-agonists. The dose of ICS is determined according to ACO severity. Leukotriene receptor antagonists and theophylline are used as add-on drugs. Macrolides and expectorants are recommended for reduction of mucus hypersecretion. Anti-IgE and anti-IL-5 antibodies, oral corticosteroids, and oxygen therapy are additional treatments for the most severe ACO. The therapeutic effects are evaluated using lung function tests, eosinophil counts in sputum and blood, FeNO, and symptom questionnaires. ACO exacerbation is treated by inhalation of short-acting ß2-agonist and systemic corticosteroids. The doses of corticosteroids are determined based on the asthma/COPD component of the exacerbation. Administration of antibiotics is recommended if sputum is purulent. Referral to specialists is necessary in cases of inability to control symptoms by medication, uncertain diagnosis with atypical features, or severe complications and comorbidities.

Foxc2 influences alveolar epithelial cell differentiation during lung development.

FOXC2, a forkhead transcriptional factor, is a candidate gene for congenital heart diseases and lymphedema-distichiasis syndrome and yellow nail syndrome; however, there are no reports on Foxc2 and the development of the lung. We have identified lung abnormalities in Foxc2-knockout embryos during investigation of cardiac development. The aim of this study was to clarify the morphological characteristics during lung development using ICR-Foxc2 knockout lungs. Mutant fetuses at embryonic days 10.5-18.5 were obtained from mating of Foxc2+/- mice and then analyzed. Notably, Foxc2-knockout lungs appeared parenchymatous and much smaller than those of the wild-type littermates. In the Foxc2 knockout lungs, the capillary beds remained distant from the alveolar epithelium until the late stages, the number of type2 alveolar cells per alveolar progenitor cell was lower and the type1 alveolar cells were thicker in Foxc2 knockout mice. In contrast, Foxc2 expression was only detected in the mesenchyme of the lung buds at E10.5, and it disappeared at E11.5 in Foxc2-LacZ knockin mice. Furthermore, the expression of Lef1 was significantly inhibited in E11.5 lungs. All of these results suggest that the abnormalities in Foxc2 knockout mice may involve maldifferentiation of alveolar epithelial cells and capillary vessel endothelial-alveolar epithelial approach as well as lymph vessel malformation. This is the first report about relationship between Foxc2 and lung development. This animal model might provide an important clue for elucidating the mechanism of lung development and the cause of respiratory diseases.

Japanese guidelines for adult asthma 2017.

Adult bronchial asthma is characterized by chronic airway inflammation, and presents clinically with variable airway narrowing (wheezes and dyspnea) and cough. Long-standing asthma induces airway remodeling, leading to intractable asthma. The number of patients with asthma has increased; however, the number of patients who die of asthma has decreased (1.2 per 100,000 patients in 2015). The goal of asthma treatment is to enable patients with asthma to attain normal pulmonary function and lead a normal life, without any symptoms. A good relationship between physicians and patients is indispensable for appropriate treatment. Long-term management by therapeutic agents and elimination of the causes and risk factors of asthma are fundamental to its treatment. Four steps in pharmacotherapy differentiate between mild and intensive treatments; each step includes an appropriate daily dose of an inhaled corticosteroid, varying from low to high levels. Long-acting ß2-agonists, leukotriene receptor antagonists, sustained-release theophylline, and long-acting muscarinic antagonist are recommended as add-on drugs, while anti-immunoglobulin E antibody and oral steroids are considered for the most severe and persistent asthma related to allergic reactions. Bronchial thermoplasty has recently been developed for severe, persistent asthma, but its long-term efficacy is not known. Inhaled ß2-agonists, aminophylline, corticosteroids, adrenaline, oxygen therapy, and other approaches are used as needed during acute exacerbations, by choosing treatment steps for asthma in accordance with the severity of exacerbations. Allergic rhinitis, eosinophilic chronic rhinosinusitis, eosinophilic otitis, chronic obstructive pulmonary disease, aspirin-induced asthma, and pregnancy are also important issues that need to be considered in asthma therapy.

Effect of tiotropium on mucus hypersecretion and airway clearance in patients with COPD.

BACKGROUND: Increased sputum production is an important feature of COPD, in which a large amount of secretions stagnated in the respiratory lumen may aggravate airflow limitation, impair airway mucociliary transport, and cause recurrent respiratory infection and, hence, acute exacerbations of the diseases. There is evidence that airway mucus hypersecretion is associated with the severity and prognosis of COPD, but the symptoms are generally difficult to treat. METHODS: In an open, non-controlled study, we examined the effect of the anticholinergic agent tiotropium on airway mucus hypersecretion in 22 COPD patients. After a 4-week run-in period, the patients received 18 µg of tiotropium once daily delivered through the handihaler for 8 weeks, while symptoms and their impact associated with sputum were scored according to cough and sputum assessment questionnaire (CASA-Q). At week 0 and week 8, spirometry was performed before and 30 min after the administration of albuterol. To test the effect of tiotropium on airway mucociliary transport, nasal clearance time was measured. To evaluate airway mucus production, solid composition of the sputum (dry/wet weight ratio) was measured. RESULTS: Treatment with tiotropium increased both prebronchodilator FEV1 and postbronchodilator FEV1. Tiotropium decreased cough symptom scores and provided with favorable influences on sputum-related symptoms, and none of the patients complained of worsening of the symptoms judging from the CASA-Q score. Both solid composition of the sputum and mucin contents decreased and nasal clearance time was shortened from 29.4 ± 5.1 to 20.6 ± 4.1min (p < 0.05) during the 8-week treatment. CONCLUSIONS: Tiotropium decreases symptoms associated with sputum in COPD patients, an effect that may be related to the inhibition of airway mucus hypersecretion and improvement of airway mucociliary clearance.

The therapy of biological agents in severe asthma.

Bronchial asthma is a heterogeneous disease characterized by airway hyperresponsiveness, smooth muscle contraction and airway inflammation. Multiple factors such as genetic back- ground and environmental factors are involved in the pathogenesis of asthma. Allergic asthma is a Th2-driven eosinophilic inflammatory disease, in which may cytokines including IL- 4, IL-5, and IL-13 play important roles. Monoclonal antibody therapies target specific mole- cules in severe asthma. Omalizumab, an IgE antibody, reduces symptoms and acute exac- erbations in severe asthma, and mepolizumab, a more recent monoclonal antibody against IL-5, is also efficacious in similar group of patients. In order to improve clinical ability and to achieve optimal health and economical benefit of biologics, further studies on clinical fac- tors and biomarkers which predict the drug efficacy are required.

Effects of regular treatment with combination of salmeterol/fluticasone propionate and salmeterol alone in cough variant asthma.

OBJECTIVE: Cough variant asthma (CVA) is an important cause of chronic cough, and pathophysiological features of the disease appear to be similar to typical asthma. Because CVA is recognized as a precursor of asthma, early intervention with long-term anti-inflammatory agents may be recommended. However, the role of combination therapy with inhaled corticosteroid and ß2-agonist in the treatment of CVA has not been elucidated. To evaluate the effectiveness of the combination therapy, we investigated the clinical impact of regular treatment with salmeterol/fliticasone propionate combination (SFC) and inhaled salmeterol (SAL) alone in patients with CVA. METHODS: The study was a randomized, controlled, parallel-group multi-center trial. Forty-three CVA patients were assigned to SFC (50/100 µg once daily) or SAL (50 µg twice daily) for 12 weeks. Then, these medications were stopped for the next 24 weeks. Main outcome measures were cough symptoms, pulmonary function and airway inflammation. RESULTS: Treatment with each of SFC and SAL significantly decreased cough scores and increased FEV1 and PEF, where the efficacy was more pronounced with SFC than SAL. SFC also decreased sputum eosinophil counts and eosinophil cationic protein contents, whereas SAL had no effect. After discontinuation of the treatment, cough scores increased, pulmonary function and eosinophilic airway inflammation were aggravated and returned to the baseline levels. CONCLUSIONS: Maintenance therapy with SFC provides further improvements in cough symptoms, pulmonary function and airway inflammation, and discontinuation of the therapy causes worsening of the disease, indicating that stopping or interrupting anti-inflammatory therapy may not be advisable in patients with CVA.

Eosinophilic otitis media is associated with asthma severity and smoking history.

PURPOSE: Eosinophilic otitis media (EOM) is an intractable otitis media characterized by an accumulation of eosinophils in the middle ear and a strong association with asthma. We investigated the relationship between EOM and asthma severity, asthma risk factors, lung function, and airway structural changes assessed by high-resolution computed tomographic (HRCT) scanning. MATERIALS AND METHODS: Forty-one asthma patients with chronic rhinosinusitis (18 men and 23 women; mean age 56 years; age range 25-82 years) were included in this study. EOM was diagnosed according to the published diagnostic criteria. Asthma severity and risk factors for asthma, such as smoking history (Brinkman index, BI), were examined. Airway wall thickness and emphysema were assessed with HRCT scanning by a blinded respiratory specialist using a validated method. Lung function was measured using standard procedures. RESULTS: EOM was diagnosed in 34% of the patients. Asthma severity, BI and airway wall thickness were each statistically greater in patients with EOM than in patients without EOM. CONCLUSION: There was a close relationship between EOM and asthma severity in asthma patients with chronic rhinosinusitis. Cessation of smoking might help prevent EOM by reducing airway wall thickness.

Budesonide/formoterol maintenance and reliever therapy in moderate-to-severe asthma: effects on eosinophilic airway inflammation.

Although the budesonide and formoterol in a single inhaler for maintenance and reliever therapy has been evaluated in recent studies, the effects on eosinophilic airway inflammation remain uncertain. The purpose of this study was to compare the efficacy, including anti-inflammatory effects, of as-needed budesonide/formoterol with salbutamol in Japanese patients with moderate-to-severe asthma. Patients with asthma using an inhaled corticosteroid plus a long-acting beta2-agonist as a controller and at least one asthma exacerbation in the previous 12 months were randomized to budesonide/formoterol maintenance therapy (160/4.5 micrograms, 2 inhalations twice daily) plus either as-needed budesonide/formoterol (160/4.5 micrograms; n = 32) or salbutamol (100 micrograms; n = 31) up to 4 inhalation daily for 48 weeks. The time to first asthma exacerbation was significantly prolonged with as-needed budesonide/formoterol compared with salbutamol (log-rank test; p = 0.0342). There was a 66% reduction in the hazard ratio for a first exacerbation with as-needed budesonide/formoterol (p = 0.0334). The frequencies of both mild and severe exacerbations and reliever use were consistently less with budesonide/formoterol than salbutamol. As-needed budesonide/formoterol significantly improved in lung function and symptom scores compared with salbutamol. In addition, the contents of eosinophil cationic protein and B12 tryptase, as well as number of eosinophils and mast cells in induced sputum, decreased to a greater extent with budesonide/formoterol compared with salbutamol. In conclusion, the budesonide and formoterol for maintenance and reliever therapy seems more effective in controlling persistent asthma with a significant reduction of airway inflammation. Clinical trial 121104, www.clinicaltrials.gov.

Macrolide effects on the prevention of COPD exacerbations.

The number of senile patients with chronic obstructive pulmonary disease (COPD) has recently increased due to an increase in life expectancy, the habit of smoking and the inhalation of toxic particles. COPD exacerbations are caused by airway bacterial and viral infections, as well as the inhalation of oxidative substrates. COPD exacerbations are associated with the worsening of symptoms and quality of life, as well as an increased mortality rate. Several drugs, including long-acting anti-cholinergic agents, long-acting ß(2)-agonists and inhaled corticosteroids, have been developed to improve symptoms in COPD patients and to prevent COPD exacerbations. Treatment with macrolide antibiotics has been reported to prevent COPD exacerbations and improve patient quality of life and symptoms, especially in those patients who have frequent exacerbations. In addition to their antimicrobial effects, macrolides have a variety of physiological functions, such as anti-inflammatory and anti-viral effects, reduced sputum production, the inhibition of biofilm formation and the inhibition of bacterial virulence factor production. These unique activities may relate to the prevention of exacerbations in COPD patients who receive macrolides. Herein, we review the inhibitory effects that macrolides have on COPD exacerbations and explore the possible mechanisms of these effects.

Chronic low-grade systemic inflammation causes DNA damage in the lungs of mice.

BACKGROUND: Whether systemic inflammation compromises the pulmonary system is largely unknown. We tested the hypothesis that chronic low-grade systemic inflammation damages alveolar wall cells. METHODS: A chronic low-grade systemic inflammatory state was induced in 8-week-old male C57/BL6J mice by administration of lipopolysaccharide (LPS, 44.4 µg/day) for a 90-day period by subcutaneous implantation of a delayed-release pellet system. Acute systemic inflammation was induced in another group of mice by a single intraperitoneal injection of LPS (125 µg/body). The lungs of mice were examined for histologic changes and genetic damage to alveolar wall cells. RESULTS: Chronic LPS exposure for a 30-day period or a 90-day period did not cause any obvious architectural changes in the lungs except for a mild level of alveolar macrophage infiltration. Despite the lack of architectural changes in the lung, immunofluorescence staining for γH2AX and phosphorylated 53BP1 showed that chronic LPS exposure resulted in an almost doubling of the number of DNA double-strand breaks (DSBs) in type 1 and type 2 alveolar epithelial cells and in alveolar endothelial cells. Acute LPS exposure also resulted in a doubling of the number of DSBs in type 1 and type 2 alveolar epithelial cells and in alveolar endothelial cells at 24 h, but the increased number of DSBs returned to the baseline level by 48 h. CONCLUSIONS: These results suggest that chronic systemic low-grade inflammation induces persistent DNA damage in alveolar epithelial and endothelial cells before architectural changes in the lung become evident.

Niflumic acid inhibits goblet cell degranulation in a guinea pig asthma model.

BACKGROUND: Human Ca(2+)-activated Cl ion channel 1 (hCLCA1) is expressed in goblet cell hyperplasia in the airway of asthmatics, and murine CLCA3 is associated with antigen-sensitized and IL-13-induced goblet cell metaplasia in mice. However, the role of CLCA in goblet cell degranulation is not fully investigated. Niflumic acid (NFA), a relatively specific CLCA inhibitor, inhibits goblet cell metaplasia, but the effect of NFA on goblet cell degranulation has not been determined in an asthma model. METHODS: Guinea pigs were sensitized with ovalbumin (OA) twice and then challenged with saline, OA, histamine, and one of the Ca(2+)-dependent secretagogues, UTP. The PAS/AB-stained mucus area in the tracheal epithelium was measured with a computer image analysis system, and the morphology of mucus granules was examined by transmission electron microscopy. In the in vitro experiment, goblet cells cultured with IL-13 at the air-liquid interface were stimulated with UTP in the presence or absence of NFA, and the MUC5AC level in cell lysates was measured by ELISA. RESULTS: The mucus areas were smaller in the OA-, histamine-, and UTP-challenged animals than in the saline-challenged animals. NFA inhibited the decrease in mucus area and morphological changes in mucus granules. UTP caused swelling and exocytosis of mucus granules and MUC5AC secretion by cultured goblet cells, and NFA inhibited these changes. CONCLUSIONS: NFA inhibited the secretory response of mucus granules in an asthma model, suggesting that CLCA may be associated with goblet cell degranulation and that CLCA inhibitors may be useful for the treatment of hypersecretion in asthma.