Middle meatus microbiome in patients with eosinophilic chronic rhinosinusitis in a Japanese population.

BACKGROUND: Chronic rhinosinusitis (CRS) is a common chronic inflammatory disease and is subdivided into eosinophilic and noneosinophilic forms. There are few reports investigating the nasal microbiome and its pathological functions in patients with CRS. OBJECTIVE: We sought to analyze factors contributing to variations of the nasal microbiome in CRS, and on the basis of these factors, to elucidate whether the bacterial metabolites were related to the pathogenesis. METHODS: Nasal swabs were collected, and the V3 to V4 variable region of the 16S ribosomal RNA gene was amplified and sequenced. Factors contributing to variations of the nasal microbiome in patients with CRS were compared. The most influential factor was whether CRS was eosinophilic, and we compared α- and ß-diversity, bacterial species, and predictive bacterial functions between the 2 patient groups. In addition, the metabolites of the key bacteria were extracted, and we evaluated the predicted bacterial functions in airway epithelial cells. RESULTS: In total, 110 patients with CRS and 33 control subjects were enrolled. On the basis of the factors of variation, it was found that patients with eosinophilic CRS (n = 65) had different microbiomes with weighted UniFrac ß-diversity and lower α-diversity compared with those with noneosinophilic CRS (n = 45). A higher abundance of Fusobacterium nucleatum and an increased LPS pathway were observed in patients with noneosinophilic CRS compared with those with eosinophilic CRS. In airway epithelial cells, LPS derived from F nucleatum suppressed the expression levels of ALOX15 induced by TH2 cytokines. CONCLUSIONS: The differences in the nasal microbiome may play a key role in the pathophysiology of CRS.

[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.

Protein tyrosine kinase Abl promotes hepatitis C virus particle assembly via interaction with viral substrate activator NS5A.

Previously, we reported that knockdown of Abl protein tyrosine kinase by shRNA or pharmacological inhibition suppresses particle assembly of J6/JFH1 strain-derived hepatitis C virus (HCV) in Huh-7.5 cells. However, the detailed mechanism by which Abl regulates HCV replication remained unclear. In this study, we established Abl-deficient (Abl-) cells through genome editing and compared HCV production between Abl- cells expressing WT or kinase-dead Abl and parental Huh-7.5 cells. Our findings revealed that Abl expression was not required from the stages of virus attachment and entry to viral gene expression; however, the kinase activity of Abl was necessary for the assembly of HCV particles. Reconstitution experiments using human embryonic kidney 293T cells revealed that phosphorylation of Tyr412 in the activation loop of Abl was enhanced by coexpression with the viral nonstructural protein 5A (NS5A) and was abrogated by the substitution of NS5A Tyr330 with Phe (Y330F), suggesting that NS5A functions as a substrate activator of Abl. Abl-NS5A association was also attenuated by the Y330F mutation of NS5A or the kinase-dead Abl, and Abl Tyr412 phosphorylation was not enhanced by NS5A bearing a mutation disabling homodimerization, although the association of Abl with NS5A was still observed. Taken together, these results demonstrate that Abl forms a phosphorylation-dependent complex with dimeric NS5A necessary for viral particle assembly, but that Abl is capable of complex formation with monomeric NS5A regardless of tyrosine phosphorylation. Our findings provide the foundation of a molecular basis for a new hepatitis C treatment strategy using Abl inhibitors.

Laundry detergents and surfactants-induced eosinophilic airway inflammation by increasing IL-33 expression and activating ILC2s.

INTRODUCTION: Epidemiological studies demonstrated that cleaning work and frequent use of cleaning products are risk factors for asthma. Laundry detergents have been reported to have epithelial barrier-opening effects. However, whether laundry detergents directly induce airway inflammation and its mechanisms in vivo remain to be elucidated. METHODS: Two commercial laundry detergents and two commonly used surfactants for cleaning and cosmetics (sodium lauryl sulfate and sodium dodecyl benzene sulfonate) were intranasally administered to mice. Lungs were analyzed using flow cytometry, histology, ELISA, and quantitative PCR. Human bronchial epithelial cells were stimulated with laundry detergents and analyzed using quantitative PCR and western blotting. Involvement of oxidative stress was assessed using an antioxidant. Dust samples from homes were analyzed to determine their detergent content by measuring their critical micelle concentration (CMC). RESULTS: The administered laundry detergents and surfactants-induced eosinophilic airway inflammation accompanied by increased IL-33 expression and activation of group 2 innate lymphoid cells (ILC2s). Detergent-induced eosinophilic airway inflammation was significantly attenuated in Rag2-/- Il2rg-/- , Il33-/- mice, and also in wild-type mice treated with NAC. Detergent-induced IL-33 expression in airways was attenuated by NAC treatment, both in vivo and in vitro. CMCs were found in all of the tested dust extracts, and they differed significantly among the homes. CONCLUSION: The laundry detergents and surfactants-induced eosinophilic airway inflammation in vivo through epithelial cell and ILC2 activation. They induced IL-33 expression in airway epithelial cells through oxidative stress. Furthermore, detergent residues were present in house dust and are presumably inhaled into the airway in daily life.

Involvement of Activation of Mast Cells via IgE Signaling and Epithelial Cell-Derived Cytokines in the Pathogenesis of Pollen Food Allergy Syndrome in a Murine Model.

Murine models to elucidate the pathogenesis of pollen food allergy syndrome (PFAS), characterized by oral hypersensitivity symptoms induced by specific foods in patients previously sensitized with a pollen, are lacking. The study aimed to examine PFAS pathogenesis in a novel murine model. Birch pollen-immunized mice were orally administered apple extract, and oral symptoms were evaluated based on oral rubbing frequency following the challenge. The birch pollen-immunized mice orally challenged with apple extract exhibited PFAS-like symptoms, including oral rubbing and positive reaction of swelling by the prick test. The apple extract administered with a protease inhibitor reduced the oral rubbing frequency, which was also significantly reduced in the immunized Fcer1a -/- and mast cell-deficient mice compared with the immunized control mice. The oral rubbing frequency, serum IgE levels, and Th2-cytokine production by the cervical lymph node cells were significantly reduced in the immunized Il-33 -/- and thymic stromal lymphopoietin receptor-deficient (Crlf2 -/-) mice as compared with the immunized wild-type mice. IL-33 and thymic stromal lymphopoietin involve the pathogenesis of PFAS. The apple-extract stimulation did not lead to increased Th2-cytokine production in the oral mucosa or number of group 2 innate lymphoid cells or eosinophils. PFAS involves an early-phase response by mast cell degranulation via IgE signaling after the cross-reactivity of Bet v 1-specific IgE and the food allergen, and exacerbation of allergic symptom via proteases in food; PFAS does not involve a late phase with local Th2/eosinophilic inflammation in the oral mucosa. This novel murine model might be used for elucidating the pathogenesis and assessing new therapeutic strategies for PFAS.

Potential of Rice-Flour Jelly Made from High-Amylose Rice as a Dysphagia Diet: Evaluation of Pharyngeal Residue by FEES.

Dysphagia diets are recommended to prevent choking and aspiration in people with dysphagia; however, rice-porridge and mashed rice-porridge, which are used as staple foods for people with dysphagia in Japan, are time-consuming to prepare. The National Agriculture and Food Research Organization has found jelly-like food products made from high-amylose rice-flour (rice-flour jelly) to be easy to prepare with a texture suitable for dysphagia diets. To investigate the potential of rice-flour jelly for the dysphagia diet, we evaluated the amount of pharyngeal residue after swallowing rice-flour jelly using fiberoptic endoscopic evaluation of swallowing and compared it with those of rice-porridge, mashed rice-porridge, and fruit jelly. We enrolled 70 participants (43 males and 27 females, aged 32-96 years, median 74.5 years) and evaluated their pharyngeal residue using the Yale Pharyngeal Residue Severity Rating Scale which includes five levels from I (none) to V (severe). Statistical analysis showed that level I was more common in fruit jelly for vallecula residue and pyriform sinus residue, and level III (mild) was more common in rice-porridge for vallecula residue (p < 0.05). No differences of pharyngeal residue were found in rice-flour jelly or mashed rice-porridge. No significant difference was observed in the number of participants with laryngeal penetration or aspiration. Therefore, rice-flour jelly is a suitable alternative to rice-porridge as a staple food for people with dysphagia in terms of food texture.

Retinoic acid promotes fibrinolysis and may regulate polyp formation.

BACKGROUND: Patients with aspirin-exacerbated respiratory disease (AERD) regularly exhibit severe nasal polyposis. Studies suggest that chronic rhinosinusitis with nasal polyps (CRSwNP) is characterized by excessive fibrin deposition associated with a profound decrease in epithelial tissue plasminogen activator (tPA). Retinoids, including vitamin A and its active metabolite retinoic acid (RA), are necessary for maintaining epithelial function and well-known inducers of tPA in endothelial cells. OBJECTIVES: This study sought to determine whether endogenous retinoids are involved in NP pathophysiology and disease severity in patients with CRSwNP and AERD. METHODS: NP tissue was collected from patients with AERD or CRSwNP, and concentrations of retinoids and fibrinolysis markers were measured using ELISA. Normal human bronchial epithelial cells were stimulated alone or in combination with RA and IL-13 for 24 hours. RESULTS: This study observed lower retinoid levels in nasal polyps of patients with AERD than those with CRSwNP or healthy controls (P < .01). Levels of the fibrin-breakdown product d-dimer were the lowest in AERD polyps (P < .01), which is consistent with lower tPA expression (P < .01). In vitro, all-trans RA upregulated tPA levels in normal human bronchial epithelial cells by 15-fold and reversed the IL-13-induced attenuation of tPA expression in cultured cells (P < .01). CONCLUSIONS: RA, a potent inducer of epithelial tPA in vitro, is reduced in tissue from patients with AERD, a finding that may potentially contribute to decreased levels of tPA and fibrinolysis in AERD. RA can induce tPA in epithelial cells and can reverse IL-13-induced tPA suppression in vitro, suggesting the potential utility of RA in treating patients with CRSwNP and/or AERD.

Executive summary: Japanese guidelines for allergic rhinitis 2020.

The Practical Guideline for the Management of Allergic Rhinitis, the fist guideline for allergic rhinitis in Japan, was prepared after a symposium held by the Japanese Society of Allergology in 1993. The current 9th edition was published in 2020 and is widely used today. The most recent collection of evidence from the literature was supplemented to the revised guideline to incorporate evidence-based medicine. The revised guideline includes updated epidemiology of allergic rhinitis in Japan, a figure representing the mechanisms of allergic rhinitis in both the onset and sensitization phases with the introduction of regulatory T cells and type 2 innate lymphoid cells, practical assessment for diagnosis, new pharmacotherapy agents such as anti-IgE mAb and a new drug delivery system for antihistamines, sublingual immunotherapy for children, dual sublingual immunotherapy for house dust mites and Japanese cedar pollen extract, new classification for surgery for allergic rhinitis, and treatment and prescriptions for older adults. An evidence-based step-by-step strategy for treatment is also described.

Dupilumab efficacy in chronic rhinosinusitis with nasal polyps from SINUS-52 is unaffected by eosinophilic status.

BACKGROUND: The human monoclonal antibody dupilumab blocks interleukin (IL)-4 andIL-13, key and central drivers of type 2 inflammation. Dupilumab, on background mometasone furoate nasal spray (MFNS), improved outcomes in the phase III SINUS-52 study (NCT02898454) in patients with severe chronic rhinosinusitis with nasal polyps (CRSwNP). This posthoc analysis of SINUS-52 examined whether eosinophilic status of CRSwNP was a predictor of dupilumab efficacy. METHODS: Patients were randomized 1:1:1 to dupilumab 300 mg every 2 weeks (q2w) until week 52; dupilumab 300 mg q2w until Week 24, then 300 mg every 4 weeks until week 52; or placebo (MFNS) until week 52. Coprimary endpoints were change from baseline in nasal polyps score (NPS), nasal congestion (NC), and Lund-Mackay score assessed by CT (LMK-CT) at week 24. Patients (n = 438) were stratified by eosinophilic chronic rhinosinusitis (ECRS) status according to the Japanese Epidemiological Survey of Refractory Eosinophilic Rhinosinusitis algorithm. RESULTS: Dupilumab significantly improved NPS, NC, and LMK-CT scores versus placebo at week 24 in all ECRS subgroups (p < 0.001), with improvements maintained or increased at week 52 (p < 0.001). There was no significant interaction between ECRS subgroup (non-/mild or moderate/severe) and dupilumab treatment effect for all endpoints at weeks 24 and 52 (p > 0.05), except LMK-CT at week 24 (p = 0.0275). Similar results were seen for the secondary endpoints. Dupilumab was well tolerated across all ECRS subgroups. CONCLUSION: Dupilumab produced consistent improvement in symptoms of severe CRSwNP irrespective of ECRS status. Therefore, blood eosinophil level may not be a suitable biomarker for dupilumab efficacy in CRSwNP.

Intranasal levels of lead as an exacerbation factor for allergic rhinitis in humans and mice.

BACKGROUND: Air pollutants are suspected to affect pathological conditions of allergic rhinitis (AR). OBJECTIVES: After detecting Pb (375 µg/kg) in Japanese cedar pollen, the effects of intranasal exposure to Pb on symptoms of AR were investigated. METHODS: Pollen counts, subjective symptoms, and Pb levels in nasal epithelial lining fluid (ELF) were investigated in 44 patients with Japanese cedar pollinosis and 57 controls from preseason to season. Effects of intranasal exposure to Pb on symptoms were confirmed by using a mouse model of AR. RESULTS: Pb levels in ELF from patients were >40% higher than those in ELF from control subjects during the pollen season but not before the pollen season. Pb level in ELF was positively associated with pollen counts for the latest 4 days before visiting a hospital as well as scores of subjective symptoms. Intranasal exposure to Pb exacerbated symptoms in allergic mice, suggesting Pb as an exacerbation factor. Pb levels in ELF and nasal mucosa in Pb-exposed allergic mice were higher than those in Pb-exposed nonallergic mice, despite intranasally challenging the same amount of Pb. Because the increased Pb level in the nasal mucosa of Pb-exposed allergic mice was decreased after washing the nasal cavity, Pb on the surface of but not inside the nasal mucosa may have been a source of increased Pb level in ELF of allergic mice. CONCLUSIONS: Increased nasal Pb level partially derived from pollen could exacerbate subjective symptoms of AR, indicating Pb as a novel hazardous air pollutant for AR.

Diversities of allergic pathologies and their modifiers: Report from the second DGAKI-JSA meeting.

In October 2021, researchers from the German Society of Allergy and Clinical Immunology (DGAKI) and from the Japanese Society of Allergology (JSA) focused their attention on the pathological conditions and modifiers of various allergic diseases. Topics included 1) the pathophysiology of IgE/mast cell-mediated allergic diseases; 2) the diagnosis and prevention of IgE/mast cell-mediated diseases; 3) the pathophysiology, diagnosis, and treatment of eosinophilic airway diseases; and 4) host-pathogen interaction and allergic diseases. This report summarizes the panel discussions, which highlighted the importance of recognizing the diversity of genetics, immunological mechanisms, and modifying factors underlying allergic diseases.

Comparison of sensitization and prevalence of Japanese cedar pollen and mite-induced perennial allergic rhinitis between 2006 and 2016 in hospital workers in Japan.

BACKGROUND: The prevalence of allergic rhinitis (AR) is increasing worldwide, mainly due to an increase in antigen exposure. We conducted an epidemiological study involving the staff of the University of Fukui Hospital and its associated hospital in 2006. There were 1540 participants aged ≥20 years, and the rates of Japanese cedar (JC) pollinosis and mite-induced perennial allergic rhinitis (PAR) were 36.8% and 15.8%, respectively. In 2016, we conducted a second survey. METHODS: The rate of sensitization to JC pollen and mites and the prevalence of JC pollinosis and mite-induced PAR were analyzed based on data from questionnaires and antigen-specific immunoglobulin E (IgE) levels. RESULTS: In the present study, we analyzed data of 1472 participants aged between 20 and 59 years. Total sensitization to JC pollen and total prevalence of JC pollinosis were 57.8% (851/1472) and 40.8% (601/1472), respectively. Total sensitization to mites and total prevalence of mite-induced PAR were 41.4% (610/1472) and 18.8% (276/1472), respectively. Total prevalence of JC pollinosis and mite-induced PAR increased significantly over a decade. Among the 334 people who participated in the 2006 and 2016 cross-sectional studies, 13% of JC pollinosis and 36% of mite-induced PAR experienced remission. However, since the number of new onset cases was higher that the number of remission cases, a slight increase in prevalence was observed over a decade. CONCLUSIONS: The prevalence of JC pollinosis and mite-induced PAR continues to show increasing trends, accompanied by an increase in antigen exposure. The remission rate of JC pollinosis was particularly low.

Efficacy and safety of dupilumab in patients with severe chronic rhinosinusitis with nasal polyps (LIBERTY NP SINUS-24 and LIBERTY NP SINUS-52): results from two multicentre, randomised, double-blind, placebo-controlled, parallel-group phase 3 trials.

BACKGROUND: Patients with chronic rhinosinusitis with nasal polyps (CRSwNP) generally have a high symptom burden and poor health-related quality of life, often requiring recurring systemic corticosteroid use and repeated sinus surgery. Dupilumab is a fully human monoclonal antibody that inhibits signalling of interleukin (IL)-4 and IL-13, key drivers of type 2 inflammation, and has been approved for use in atopic dermatitis and asthma. In these two studies, we aimed to assess efficacy and safety of dupilumab in patients with CRSwNP despite previous treatment with systemic corticosteroids, surgery, or both. METHODS: LIBERTY NP SINUS-24 and LIBERTY NP SINUS-52 were two multinational, multicentre, randomised, double-blind, placebo-controlled, parallel-group studies assessing dupilumab added to standard of care in adults with severe CRSwNP. SINUS-24 was done in 67 centres in 13 countries, and SINUS-52 was done in 117 centres in 14 countries. Eligible patients were 18 years or older with bilateral CRSwNP and symptoms despite intranasal corticosteroid use, receiving systemic corticosteroids in the preceding 2 years, or having had sinonasal surgery. Patients in SINUS-24 were randomly assigned (1:1) to subcutaneous dupilumab 300 mg or placebo every 2 weeks for 24 weeks. Patients in SINUS-52 were randomly assigned (1:1:1) to dupilumab 300 mg every 2 weeks for 52 weeks, dupilumab every 2 weeks for 24 weeks and then every 4 weeks for the remaining 28 weeks, or placebo every 2 weeks for 52 weeks. All patients were randomly assigned centrally with a permuted block randomisation schedule. Randomisation was stratified by asthma or non-steroidal anti-inflammatory drug-exacerbated respiratory disease status at screening, previous surgery at screening, and country. Patients with or without comorbid asthma were included. Coprimary endpoints were changes from baseline to week 24 in nasal polyp score (NPS), nasal congestion or obstruction, and sinus Lund-Mackay CT scores (a coprimary endpoint in Japan), done in an intention-to-treat population. Safety was assessed in a pooled population of both dupilumab groups in SINUS-52 up to week 24 and the dupilumab group in SINUS-24 and the placebo groups in both studies until week 24. The trials are complete and registered at ClinicalTrials.gov, NCT02912468 and NCT02898454. FINDINGS: Between Dec 5, 2016, and Aug 3, 2017, 276 patients were enrolled in SINUS-24, with 143 in the dupilumab group and 133 in the placebo group receiving at least one study drug dose. Between Nov 28, 2016, and Aug 28, 2017, 448 patients were enrolled in SINUS-52, with 150 receiving at least one dose of dupilumab every 2 weeks, 145 receiving at least one dose of dupilumab every 2 weeks for 24 weeks and every 4 weeks until week 52, and 153 receiving at least one dose of placebo. Dupilumab significantly improved the coprimary endpoints in both studies. At 24 weeks, least squares mean difference in NPS of dupilumab treatment versus placebo was -2·06 (95% CI -2·43 to -1·69; p<0·0001) in SINUS-24 and -1·80 (-2·10 to -1·51; p<0·0001) in SINUS-52; difference in nasal congestion or obstruction score was -0·89 (-1·07 to -0·71; p<0·0001) in SINUS-24 and -0·87 (-1·03 to -0·71; p<0·0001) in SINUS-52; and difference in Lund-Mackay CT scores was -7·44 (-8·35 to -6·53; p<0·0001) in SINUS-24 and -5·13 (-5·80 to -4·46; p<0·0001) in SINUS-52. The most common adverse events (nasopharyngitis, worsening of nasal polyps and asthma, headache, epistaxis, and injection-site erythema) were more frequent with placebo. INTERPRETATION: In adult patients with severe CRSwNP, dupilumab reduced polyp size, sinus opacification, and severity of symptoms and was well tolerated. These results support the benefits of adding dupilumab to daily standard of care for patients with severe CRSwNP who otherwise have few therapeutic options. FUNDING: Sanofi and Regeneron Pharmaceuticals.

Charcot-Leyden crystal formation is closely associated with eosinophil extracellular trap cell death.

Protein crystallization in human tissue rarely occurs. Charcot-Leyden crystals (CLCs) were described in various eosinophilic diseases >150 years ago, but our understanding of CLC formation still remains limited. In this study, we demonstrate that CLCs observed in varied inflamed human tissues are closely associated with eosinophil cell-free granules and nuclear envelope/plasma membrane disintegration with release of filamentous chromatin (extracellular traps), typical morphologies of a regulated pathway of extracellular trap cell death (ETosis). During the process of eosinophil ETosis, eccentrically localized cytoplasmic and perinuclear CLC protein (galectin-10) is homogeneously redistributed in the cytoplasm. Rapid (1-2 minutes) formation of intracytoplasmic CLCs was observed using time-lapse imaging. Plasma membrane rupture enabled the release of both intracellularly formed CLCs and soluble galectin-10 that further contributed to formation of CLCs extracellularly, in parallel with the expulsion of free intact granules and extracellular traps. CLC formation and galectin-10 release were dependent on nicotinamide adenine dinucleotide phosphate oxidase activation. To our knowledge, this is the first demonstration of natural formation of CLCs in association with an active physiological process (ie, ETosis). These results indicate that dynamic changes in intracellular localization and release of galectin-10 contribute to CLC formation in vivo and suggest that CLC/galectin-10 might serve as an indicator of ETosis.

Adult-onset eosinophilic airway diseases.

Eosinophilic airway inflammation is one of the cardinal features of allergic airway diseases such as atopic asthma and allergic rhinitis. These childhood-onset conditions are mediated by allergen and allergen-specific IgE and often accompanied by other allergic diseases including food allergy and eczema. They can develop consecutively in the same patient, which is referred to as an allergic march. In contrast, some phenotypes of asthma, nonsteroidal anti-inflammatory drugs-exacerbated airway disease (N-ERD), chronic rhinosinusitis with nasal polyps (CRSwNP)/eosinophilic CRS and allergic bronchopulmonary aspergillosis/mycosis (ABPA/ABPM) are adult-onset airway diseases, which are characterized by prominent peripheral blood eosinophilia. Most of these conditions, except for ABPA/ABPM, are nonatopic, and the coexistence of multiple diseases, including an adult-onset eosinophilic systemic disease, eosinophilic granulomatosis with polyangiitis (EGPA), is common. In this review, we focus on eosinophil biology, genetics and clinical characteristics and the pathophysiology of adult-onset eosinophilic asthma, N-ERD, CRSwNP/eosinophilic CRS, ABPA/ABPM and EGPA, while exploring the common genetic, immunological and pathological conditions among these adult-onset eosinophilic diseases.

Human cystatin SN is an endogenous protease inhibitor that prevents allergic rhinitis.

BACKGROUND: Protease allergens disrupt epithelial barriers to exert their allergenicity. Cystatin SN (encoded by CST1) is an endogenous cysteine protease inhibitor upregulated in nasal epithelia in patients with allergic rhinitis (AR). OBJECTIVE: We sought to investigate the protective effect of human cystatin SN on AR symptoms using pollen-induced AR mouse models. METHODS: We performed an in vitro protease activity assay to evaluate the effect of recombinant human cystatin SN (rhCystatin SN) on Japanese cedar (JC) or ragweed proteases. A human nasal epithelial cell line, RPMI 2650, was used to examine tight junction (TJ) disruption in vitro. Mice were sensitized and nasally challenged with JC or ragweed pollens with or without rhCystatin SN to examine the effect of rhCystatin SN on AR symptoms and the epithelial barrier in vivo. Because mice lack CST1, we generated transgenic (Tg) mice expressing human CST1 under control of its genomic control region (hCST1-Tg mice) to examine the role of cystatin SN in physiologically expressed conditions. RESULTS: rhCystatin SN inhibited JC but not ragweed protease activities and prevented JC-induced but not ragweed-induced TJ disruption in vitro. Exogenous administration of rhCystatin SN ameliorated JC-induced but not ragweed-induced sneezing and nasal TJ disruption in vivo. Furthermore, hCST1-Tg mice showed decreased JC-induced but not ragweed-induced sneezing symptoms and nasal TJ disruption compared with wild-type mice. CONCLUSION: Human cystatin SN suppresses AR symptoms through inhibiting allergen protease activities and protecting the nasal TJ barrier in an allergen-specific manner. We propose that upregulation of nasal endogenous protease inhibitors, including cystatin SN, is a novel therapeutic strategy for protease allergen-induced AR.

Increased thrombin-activatable fibrinolysis inhibitor levels in patients with chronic rhinosinusitis with nasal polyps.

BACKGROUND: Chronic rhinosinusitis (CRS) is a heterogeneous chronic inflammatory disease subdivided based on the presence or absence of nasal polyps (NPs). Histologic features of chronic rhinosinusitis with nasal polyps (CRSwNP) include inflammatory cell infiltration and excessive fibrin deposition in NPs. Thrombin-activatable fibrinolysis inhibitor (TAFI) is an enzyme that plays an antifibrinolytic role in the body. The significance of TAFI has been documented in patients with chronic inflammatory diseases, including chronic lung disease; however, it has not been evaluated in the pathogenesis of NPs. OBJECTIVE: The objective of this study was to evaluate the potential role of TAFI in the pathogenesis of NPs. METHODS: Nasal lavage fluid was collected from control subjects and patients with CRS. We measured levels of thrombin/anti-thrombin complex (TATc) and TAFI protein using an ELISA. RESULTS: TATc levels in nasal lavage fluid were significantly increased in patients with CRSwNP and patients with chronic rhinosinusitis without nasal polyps (CRSsNP) compared with control subjects, and TAFI levels in nasal lavage fluid were also significantly increased in patients with CRSwNP compared with those in control subjects and patients with CRSsNP. There was a significant correlation between TATc and TAFI levels in nasal lavage fluid. Interestingly, patients with CRS and asthma showed increased TATc and TAFI levels in nasal lavage fluid compared with those in patients with CRS without asthma, especially patients with CRSwNP. CONCLUSIONS: Increased TATc and TAFI levels in nasal passages of patients with CRSwNP might participate in fibrin deposition in NPs and might play a role in the pathogenesis of CRSwNP and asthma.

The roles of IL-5 and anti-IL-5 treatment in eosinophilic diseases: Asthma, eosinophilic granulomatosis with polyangiitis, and eosinophilic chronic rhinosinusitis.

IL-5 is the most potent activator of eosinophils and is produced by Th2 cells and ILC2s. A role for IL-5 in eosinophil extracellular trap cell death, i.e., a proinflammatory cell death, has also been reported. Mepolizumab and benralizumab are humanized mAbs that target IL-5 and the IL-5 receptor α, respectively, and their therapeutic efficacy for severe asthma has been established. Although consistent differences in the efficacies of those drugs have not been proven, benralizumab extensively depleted eosinophils via Ab-dependent cell-mediated cytotoxicity. Blood eosinophil count, but not FeNO or IgE, is the best-established predictive biomarker of the efficacy of anti-IL-5 treatment. Regarding the choice of biologics, the balance between blood eosinophil count and FeNO, indication of comorbidities, longitudinal safety, and interval of injection should be considered. Mepolizumab was also effective in maintaining the remission of refractory eosinophilic granulomatous polyangiitis. Moreover, mepolizumab decreased the proportion of patients who required surgery and lowered the nasal polyp score in patients with chronic rhinosinusitis with nasal polyps; a further extensive trial is currently under way. In a phase II benralizumab study performed in Japan, no significant effect on nasal polyp score at week 12 was observed, suggesting a requirement for longer treatment. In this review, the role of IL-5 in eosinophil biology and the current status of anti-IL-5 therapy are discussed. The longitudinal safety of anti-IL-5 therapy has been increasingly established, and this strategy will be continuously indicated for eosinophilic diseases as a specific treatment for eosinophilic inflammation.

Dupilumab: Basic aspects and applications to allergic diseases.

Interleukin (IL)-4 and IL-13, signature type 2 cytokines, exert their actions by binding to two types of receptors sharing the IL-4R α chain (IL-4Rα). Since IL-4 and IL-13 play important and redundant roles in the pathogenesis of allergic diseases, blocking both the IL-4 and IL-13 signals would be a powerful and effective strategy for treating allergic diseases. Dupilumab (Dupixent®) is a fully human monoclonal antibody recognizing IL-4Rα and blocking both the IL-4 and IL-13 signals. Dupilumab was first prescribed for atopic dermatitis (AD) patients and has been widely approved for adult patients with moderate to severe AD since 2018. Dupilumab has since been used for asthma, receiving approval for uncontrolled asthma in 2019. A phase 3 study using dupilumab for chronic rhinosinusitis with nasal polyps (CRSwNP) has been just completed, with positive results. Several clinical trials of dupilumab for other diseases in which type 2 inflammation is dominant are now underway. It is hoped that dupilumab will open the door to a new era for treating allergic patients with AD, asthma, and CRSwNP, and for more patients with type 2 inflammations.

Japanese guidelines for allergic rhinitis 2020.

Like asthma and atopic dermatitis, allergic rhinitis is an allergic disease, but of the three, it is the only type I allergic disease. Allergic rhinitis includes pollinosis, which is intractable and reduces quality of life (QOL) when it becomes severe. A guideline is needed to understand allergic rhinitis and to use this knowledge to develop a treatment plan. In Japan, the first guideline was prepared after a symposium held by the Japanese Society of Allergology in 1993. The current 8th edition was published in 2016, and is widely used today. To incorporate evidence based medicine (EBM) introduced from abroad, the most recent collection of evidence/literature was supplemented to the Practical Guideline for the Management of Allergic Rhinitis in Japan 2016. The revised guideline includes assessment of diagnosis/treatment and prescriptions for children and pregnant women, for broad clinical applications. An evidence-based step-by-step strategy for treatment is also described. In addition, the QOL concept and cost benefit analyses are also addressed. Along with Allergic Rhinitis and its Impact of Asthma (ARIA), this guideline is widely used for various clinical purposes, such as measures for patients with sinusitis, childhood allergic rhinitis, oral allergy syndrome, and anaphylaxis and for pregnant women. A Q&A section regarding allergic rhinitis in Japan was added to the end of this guideline.