Translational research in head and neck cancer: Molecular and immunological updates

Head and neck squamous cell carcinoma (HNSCC) has a poor prognosis. Each year, approximately 880,000 patients are newly diagnosed with HNSCC worldwide, and 450,000 patients with HNSCC die. Risk factors for developing HNSCC have been identified, with cigarette smoking, alcohol consumption, and viral infections being the major factors. Owing to the prevalence of human papillomavirus infection, the number of HNSCC cases is increasing considerably. Surgery and chemoradiotherapy are the primary treatments for HNSCC. With advancements in tumor biology, patients are eligible for novel treatment modalities, namely targeted therapies, immunotherapy, and photoimmunotherapy. Because this area of research has rapidly progressed, clinicians should understand the basic biology of HNSCC to choose an appropriate therapy in the upcoming era of personalized medicine. This review summarized recent developments in tumor biology, focusing on epidemiology, genetic/epigenetic factors, the tumor microenvironment, microbiota, immunity, and photoimmunotherapy in HNSCC, as well as how these findings can be translated into clinical settings.

The current findings in eosinophilic chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a persistent inflammatory disease of the nasal cavity and paranasal sinuses. Traditional classification is denoted by the presence (CRSwNP) or absence of nasal polyps (CRSsNP). Particularly, CRSwNP is distinguished by the presence of infiltrating cells and inflammatory markers in the nasal mucosa. Patients with CRSwNP in Western countries predominantly display a type 2 endotype, whereas those in Asian regions display a mixed type 2 endotype. Nevertheless, recent transcriptome analyses have revealed two types of nasal polyps - type 2 and non-type 2 polyps, suggesting that geographical differences in endotypes likely resulted from the different proportions of each endotype. Moreover, various endotypes of CRSsNP have been identified, making phenotype a crucial factor for predicting treatment efficacy. Type 2 endotypes, designated as eosinophilic CRS (ECRS) in Japan, are characterized by severe eosinophilic infiltration into the paranasal sinus tissue and are particularly refractory. In this review, we discuss the latest developments in ECRS. We also provide recent findings on the involvement of nasal epithelial cells in pathogenesis.

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 β-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 β-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.

Liquid-based cytology (LBC) with immunocytochemical staining improves fine-needle aspiration cytology (FNA) performance for salivary gland tumors

BACKGROUND

Liquid-based cytology (LBC), now used globally for the head and neck region, has been used at our hospital since 2011. This study was designed to analyze the efficacy of LBC with immunocytochemical staining on preoperative diagnosis of salivary gland tumors.

METHODS

This retrospective analysis of fine-needle aspiration (FNA) performance for salivary gland tumors was conducted at Fukui University Hospital. Salivary gland tumor operations conducted during April 2006 - December 2010 (84 cases) were classified as the Conventional Smear (CS) group, which were diagnosed morphologically by Papanicolaou and Giemsa staining. Those done during January 2012 - April 2017 (112 cases) were classified as the LBC group, which were diagnosed using LBC samples with immunocytochemical staining. The FNA results and pathological diagnosis of both groups were analyzed to calculate the FNA performance.

RESULTS

Compared to the CS group, cases of inadequate and indeterminate FNA sample were not reduced significantly by LBC with immunocytochemical staining. As for FNA performance, the accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of CS group were, respectively, 88.7%, 53.3%, 100%, 100%, and 87.0%. Those of LBC group were all 100%, representing significant improvement over the CS group.

CONCLUSIONS

Analysis results indicated the usefulness of LBC with immunocytochemical staining for preoperative diagnosis of salivary gland tumors.

The functional role and the clinical application of periostin in chronic rhinosinusitis

INTRODUCTION

Chronic rhinosinusitis (CRS) comprises several heterogenous groups, now classified based on endotype more often than on phenotype. A number of studies aimed at finding a useful biomarker for type 2 CRS suggest that periostin is a promising surrogate.

AREAS COVERED

A comprehensive overview of the clinical significance of tissue periostin expression and serum periostin in CRS patients is provided. The effects of comorbid asthma on serum periostin and samples other than serum in which periostin can be detected in CRS patients are also discussed. Moreover, the functional roles of periostin in CRS pathogenesis are summarized.

EXPERT OPINION

The position of periostin as a signature biomarker of type 2 CRS has been well established, enabling us to classify CRS patients by endotyping. Serum periostin is useful not only for endotyping CRS patients, but also for estimating disease severity, comorbidity, prognosis, and response to treatment, and in particular, predicting recurrence after surgery. However, it remains to be addressed how we apply serum periostin to using biologics for CRS patients. Further studies aimed at showing periostin to be a therapeutic target for CRS are awaited.

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.

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.

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.

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.

The Percentage of PNAd-Expressing Vessels is Correlated with Disease Severity in Eosinophilic Chronic Rhinosinusitis

BACKGROUND

Eosinophilic chronic rhinosinusitis (ECRS) is a chronic inflammatory condition of the paranasal sinuses characterized by intractable nasal polyps with prominent eosinophil infiltration. These eosinophils are presumably recruited from peripheral blood via vessels expressing peripheral lymph node addressin (PNAd), a set of glycoproteins decorated with 6-sulfo sialyl Lewis x (sLe^x) glycans that serve as L-selectin ligands. Based on the severity classification algorithm proposed by the Japanese Epidemiological Survey of Refractory Eosinophilic Chronic Rhinosinusitis (JESREC) study group, ECRS is divided into mild, moderate and severe groups; however, as yet there are few reports comparing the clinicopathological differences among these groups.

OBJECTIVE

Our goal was to elucidate clinicopathological differences among the three different severities of ECRS with special reference to eosinophils and PNAd-expressing vessels.

METHODS

We performed quantitative immunohistochemical analysis of PNAd-expressing vessels using surgical specimens of nasal polyps from patients exhibiting varying severity of ECRS (n = 35) and from individuals with non-ECRS (n = 10). To this end, we immunostained tissue sections with anti-PNAd and anti-CD34 monoclonal antibodies, and then determined the number of vessels immunolabeled with each antibody.

RESULTS

The number of eosinophils infiltrating nasal polyps was correlated with ECRS severity. We also found that the PNAd + /CD34 + vessel ratio, namely, the percentage of PNAd-expressing vessels among all vessels, was positively correlated not only with ECRS severity but also with the number of eosinophils infiltrating nasal polyps formed in ECRS.

CONCLUSION

These results strongly suggest that PNAd-expressing vessels play at least a partial role in eosinophil recruitment to nasal polyps and consequent severity of ECRS.

Cellular Profiles of Prodynorphin and Preproenkephalin mRNA-Expressing Neurons in the Anterior Olfactory Tubercle of Mice

The olfactory tubercle (OT) is a striatal region that receives olfactory inputs. mRNAs of prodynorphin (Pdyn) and preproenkephalin (Penk), precursors of dynorphins and enkephalins, respectively, are strongly expressed in the striatum. Both produce opioid peptides with various physiological effects such as pain relief and euphoria. Recent studies have revealed that OT has anatomical and cytoarchitectonic domains that play different roles in odor-induced motivated behavior. Neuronal subtypes of the OT can be distinguished by their expression of the dopamine receptors D1 (Drd1) and D2 (Drd2). Here, we addressed whether and which type of opioid peptide precursors the D1- and D2-expressing neurons in the OT express. We used multiple fluorescence in situ hybridization for mRNAs of the opioid precursors and dopamine receptors to characterize mouse OT neurons. Pdyn was mainly expressed by Drd1-expressing cells in the dense cell layer (DCL) of the OT, whereas Penk was expressed primarily by Drd2-expressing cells in the DCL. We also confirmed the presence of a larger population of Pdyn-Penk-Drd1 co-expressing cells in the DCL of the anteromedial OT compared with the anterolateral OT. These observations will help understand whether and how dynorphins and enkephalins in the OT are involved in diverse odor-induced motivated behaviors.

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.

The anatomy of the foramina and efferent nerve fibers from the pterygopalatine ganglion in posterolateral nasal wall

Background

The advance of endoscopic surgery has enabled selective section of the postganglionic nerve branches from pterygopalatine ganglion (PPG) as a modification of the vidian neurectomy. Recent microanatomic studies have suggested that the nasal mucosa is also innervated by multiple efferent rami associated with the sphenopalatine artery (SPA) in the procedure “posterior nasal neurectomy.” This anatomic cadaveric study aims to identify all postganglionic nerve fibers in the lateral nasal wall which should inform future surgical procedures aimed at interrupting these nerve fibers.

Methods

Two cadaver heads, with a total of three individual sides, were dissected. All neurovascular structures penetrating the vertical plate of palatine bone were carefully identified following meticulous removal of the overlying mucosa layers. The efferent nerve fibers were identified and dissected back to their origin—the PPG or greater palatine nerve.

Results

Several foramina with efferent PPG nerves were identified on the vertical plate of the palatine bone and medial pterygoid plate. The superior, middle, and inferior turbinates (IT) were innervated by efferent nerves from the PPG via the anterior region of the SPA. The IT was innervated from nerves originating from behind the SPA through bony foramina. The lateral wall of inferior meatus was innervated by efferent nerves that originated from greater palatine nerve and pharyngeal nerve.

Conclusion

This study demonstrated the anatomical positions of the postganglionic nerves that innervate the lateral nasal wall. These nerves are located anterior to the SPA as well as posterior to the SPA, where they penetrate the palatine bone.

Level of evidence: NA.

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.

Elevated Serum Leptin Levels in Patients With Eosinophilic Chronic Rhinosinusitis

Background: Eosinophilic chronic sinusitis (ECRS) is a subtype of CRS with nasal polyps (CRSwNP) that is frequently comorbid with asthma. Notably, ECRS patients often show a high recurrence of NPs after surgical resection. Leptin is a hormone produced by adipocytes that has been implicated in airway inflammatory diseases. However, to date, the role of leptin in ECRS has not been investigated. Objective: To determine whether the serum levels of leptin are altered in patients with ECRS. Methods: In total, 40 patients with ECRS, 15 patients with non-eosinophilic CRS (non-ECRS), and 12 individuals without CRS (control) were included in this study. Patient's serum leptin levels were assessed, and the number of eosinophils in their NPs were measured through a histological evaluation of the three densest areas with cellular infiltrate beneath the epithelial surface. Finally, nasal fibroblast cultures established from NPs were stimulated with varying concentrations of recombinant leptin in vitro to determine whether leptin affects eotaxin-3 (Chemokine (C-C motif) ligand 26 :26: CCL26) expression. Results: The serum leptin levels in both the ECRS and non-ECRS groups were significantly higher than those in the control subjects (p < 0.0001 vs. ECRS; p < 0.05 vs. non-ECRS). Furthermore, ECRS patients displayed significantly elevated serum leptin levels compared to non-ECRS patients (p < 0.001), although there was no difference in body mass index between the groups. Notably, serum leptin levels were correlated with the proportion of eosinophils in peripheral blood (r = 0.3575, p < 0.01) and the number of eosinophils in NPs (r = 0.5109, p < 0.0001). Serum leptin levels were also correlated with eotaxin-3 mRNA expression in NPs (r = 0.5374, p < 0.01). Finally, leptin significantly augmented eotaxin-3 expression in nasal fibroblasts established in vitro from NPs in a leptin receptor-dependent manner (p < 0.05). Conclusion: Leptin levels are elevated in ECRS patients and may both promote and indicate the severity of ECRS as well as systemic type 2-biased inflammatory responses. Combined, these data indicate that circulating leptin may play a significant role in the development of eosinophilic inflammation in NPs.

Regulation of the Expression of SARS-CoV-2 Receptor Angiotensin-Converting Enzyme 2 in Nasal Mucosa

BACKGROUND

Coronavirus disease 2019 (COVID-19) has caused a global pandemic. Higher expression of the virus receptor angiotensin-converting enzyme 2 (ACE2) in the nasal mucosa may be associated with high transmissibility and asymptomatic infection. In COVID-19, the elucidation of the determinants of ACE2 expression at nasal tissue level is crucial. The development of strategies to downregulate ACE2 expression in nasal epithelial cells might reduce transmission and be useful as a novel therapeutic approach.

OBJECTIVE

To verify ACE2 expression in the nasal mucosa of patients with seasonal allergic rhinitis induced by Japanese cedar pollen (SAR-JCP) and chronic rhinosinusitis with nasal polyp (CRSwNP) and to examine the effects of short-chain fatty acids (SCFAs) on ACE2 expression in airway epithelial cells.

METHODS

We assessed ACE2 expression in the nasal mucosa of control subjects, patients with SAR-JCP, and those with CRSwNP using real-time polymerase chain reaction. We also quantified ACE2 gene expression in cultured airway epithelial cells.

RESULTS

Although ACE2 expression was greatly increased in a few patients with SAR-JCP during the Japanese cedar pollen season, mean levels were not significantly increased. ACE2 mRNA expression was significantly decreased in nasal polyp tissue from patients with chronic rhinosinusitis compared with the expression in that from control subjects. SCFAs generated by gastrointestinal microbiota significantly reduced resting ACE2 expression in cultured airway epithelial cells. SCFAs also significantly suppressed the dsRNA-dependent upregulation of ACE2 expression in airway epithelial cells.

CONCLUSION

Inflammatory endotype affects ACE2 expression in the nasal mucosa and influences susceptibility to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In particular, type 2 inflammation could downregulate ACE2 expression in the nasal mucosa and reduces susceptibility to SARS-CoV-2 in patients with CRSwNP. Although in vivo experiments are required, administration of SCFAs to the nasal cavity might be worthy of consideration as a preventative or therapeutic strategy for the early-stage COVID-19.

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.

Survey of nebulizer therapy for nasal inflammatory diseases in Japan before and during the COVID-19 pandemic

Objective: Nebulizer therapy is an effective and safe topical treatment for rhinosinusitis and is frequently used by otolaryngologists in Japan. However, treatment methods used vary among regions and according to doctors’ preferences. In this study, we aimed to investigate the use of nebulizer therapy for rhinosinusitis. Administration of nebulizer therapy has been affected by the coronavirus disease 2019 (COVID-19) pandemic. Thus, we also investigated the difference in the prevalence of nebulizer use before and during the pandemic.

Methods: Between February and September 2016 and in January 2021, we administered questionnaire surveys on nebulizer treatment for rhinosinusitis to otorhinolaryngologists, who were members of the Oto-Rhino-Laryngological Society of Japan, in Aomori, Saitama, Mie, Fukui, Shiga, Okayama, and Kagoshima prefectures.

Results: More than 90% of the otorhinolaryngologists performed nebulizer treatment for rhinosinusitis in 2016. In April 2020 (the first wave of the COVID-19 pandemic), the use rate decreased to 20%, but in January 2021, the use rate increased to 60%. Jet nebulizers were the most frequently used type. One-third of the otolaryngologists enlarged the natural opening of the paranasal sinuses in more than half of their patients by using vasoconstrictors. Cefmenoxime and betamethasone were the most commonly used antibiotics and steroids, respectively.

Conclusion: Because it is important to perform nasal pretreatment and strict disinfection of nebulizer equipment, it is clear that education of otorhinolaryngologists as well as paramedical personnel is required to ensure safe and effective use of nebulizer therapy in Japan.

Trimellitic anhydride facilitates transepithelial permeability disrupting tight junctions in sinonasal epithelial cells

Trimellitic anhydride (TMA) is a chemical agent classified as a low molecular weight (LMW) agent causing occupational rhinitis (OR) or asthma. Although TMA is recognized as a respiratory sensitizer, the direct and non-immunologic effects of TMA remain unclear. Air- liquid interface (ALI) cultured human nasal epithelial cells (HNECs) derived from control subjects were treated with TMA, followed by measurement of the transepithelial electrical resistance (TEER), paracellular permeability of fluorescein isothiocyanate (FITC)-dextran and immunofluorescence of tight junction proteins claudin-1 and zonula occludens-1 (ZO-1). The cytotoxicity of TMA was evaluated by lactate dehydrogenase (LDH) assay. TMA at concentrations of 2 and 4 mg/mL significantly reduced the TEER within 10 min (p = 0.0177 on 2 mg/mL; p < 0.0001 on 4 mg/mL). The paracellular permeability of FITC-dextran was significantly increased upon challenge with 4 mg/mL TMA for 3 h (p = 0.0088) and 6 h (p = 0.0004). TMA treatment induced a reduction in the fluorescence intensity of claudin-1 and ZO-1 in a dose-dependent manner. LDH assay revealed 4 mg/mL TMA induced cytotoxicity only after 6 h incubation, while 1 or 2 mg/mL TMA caused no cytotoxicity. Our results suggest that TMA has a potential to penetrate the epithelial barrier by disrupting claudin-1 and ZO-1, indicating an important role for sensitization and OR development.

Der p 1 Disrupts the Epithelial Barrier and Induces IL-6 Production in Patients With House Dust Mite Allergic Rhinitis

Background:Dermatophagoides pteronyssinus 1/2 (Der p 1/Der p 2) are regarded as important allergens of house dust mite (HDM). However, the effect of both products on the epithelial barrier and immune response of patients with and without HDM allergic rhinitis (AR) remains unclear.

Methods: Air–liquid interface (ALI) cultured human nasal epithelial cells (HNECs) derived from control subjects (non-AR) (n = 9) and HDM-AR patients (n = 9) were treated with Der P 1 and Der P 2, followed by testing the transepithelial electrical resistance (TEER), paracellular permeability of fluorescein isothiocyanate (FITC)-dextrans and immunofluorescence of claudin-1 and ZO-1. Interleukin-6 (IL-6) production was evaluated by ELISA.

Results: Der p 1 reduced TEER significantly in a transient and dose-dependent manner in HNEC-ALI cultures from HDM-AR and non-AR patients, whilst the paracellular permeability was not affected. TEER was significantly reduced by Der p 1 at the 10-min time point in HDM-AR patients compared to non-AR patients (p = 0.0259). Compared to no-treatment control, in HNECs derived from HDM-AR patients, Der p 1 significantly cleaved claudin-1 after 30 min exposure (72.7 ± 9.5 % in non-AR group, 39.9 ± 7.1 % in HDM-AR group, p = 0.0286) and induced IL-6 secretion (p = 0.0271).

Conclusions: Our results suggest that patients with HDM-AR are more sensitive to Der p 1 than non-AR patients with increased effects of Der p1 on the mucosal barrier and induction of inflammation, indicating an important role for Der p1 in sensitization and HDM-AR development.

ORMDL3 overexpression facilitates FcεRI-mediated transcription of proinflammatory cytokines and thapsigargin-mediated PERK phosphorylation in RBL-2H3 cells

Introduction

The chromosomal region 17q21 harbors the human orosomucoid‐like 3 (ORMDL3) gene and has been linked to asthma and other inflammatory diseases. ORMDL3 is involved in the unfolded protein response (UPR), lipid metabolism, and inflammatory reactions. We investigated the effects of ORMDL3 overexpression in RBL‐2H3 cells to determine the contribution of ORMDL3 to inflammatory disease development.

Methods

We generated ORMDL3 stably overexpressing RBL‐2H3 cells to assess degranulation, transcriptional upregulation of interleukin‐4 (IL‐4), tumor necrosis factor‐α (TNF‐α), monocyte chemoattractant protein‐1 (MCP‐1), and mitogen‐activated protein kinase (MAPK) phosphorylation via FcεRI. In addition, we examined the effects of ORMDL3 overexpression on thapsigargin (TG)‐mediated proinflammatory cytokine transcription and UPR by monitoring MAPK, protein kinase‐like endoplasmic reticulum kinase (PERK), and inositol‐requiring enzyme 1 (IRE1) phosphorylation.

Results

Overexpression of ORMDL3 enhanced IL‐4, TNF‐α, and MCP‐1 expression after FcεRI cross‐linking, whereas the sphingosine‐1‐phosphate (S1P) agonist FTY720 suppressed this enhancement. There was no significant difference in degranulation and MAPK phosphorylation via FcεRI‐mediated activation between vector‐transfected and ORMDL3‐overexpressing cells. ORMDL3 overexpression accelerated TG‐mediated PERK phosphorylation, while MAPK phosphorylation and proinflammatory cytokine expression showed no significant changes in ORMDL3‐overexpressing cells.

Conclusions

Our findings suggest that ORMDL3 plays an important role in regulating proinflammatory cytokine expression via the S1P pathway and selectively affects the UPR pathway in mast cells.

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.

Dupilumab reduces systemic corticosteroid use and sinonasal surgery rate in CRSwNP

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a type 2 inflammatory disease with a high symptom burden and poor quality of life. Treatment options include recurrent surgeries and/or frequent systemic corticosteroids (SCS). Dupilumab, a fully human monoclonal antibody, blocks the shared receptor component for interleukin-4 and interleukin-13, key drivers of type 2-mediated inflammation. We report results of pooled analyses from 2 randomised, double-blind, placebo-controlled phase 3 studies (SINUS 24 [NCT02912468]; SINUS-52 [NCT02898454]) to evaluate dupilumab effect versus placebo in adults with CRSwNP with/without SCS use and sinonasal surgery.

METHODOLOGY

SINUS-24 patients were randomised 1:1 to subcutaneous dupilumab 300 mg (n=143) or placebo (n=133) every 2 weeks (q2w) for 24 weeks. SINUS-52 patients were randomised 1:1:1 to 52 weeks of subcutaneous dupilumab 300 mg q2w (n=150), 24 weeks q2w followed by 28 weeks of dupilumab 300 mg every 4 weeks (n=145) or 52 weeks of placebo q2w (n=153).

RESULTS

Dupilumab reduced the number of patients undergoing sinonasal surgery (82.6%), the need for in-study SCS use (73.9%), and SCS courses (75.3%). Significant improvements were observed with dupilumab vs placebo regardless of prior sinonasal surgery or SCS use in nasal polyp, nasal congestion, Lund-MacKay, and Sinonasal Outcome Test (22-items) scores, and the University of Pennsylvania Smell Identification Test.

CONCLUSIONS

Dupilumab demonstrated significant improvements in disease signs and symptoms and reduced the need for sino-nasal surgery and SCS use versus placebo in patients with severe CRSwNP, regardless of SCS use in the previous 2 years, or prior sinonasal surgery.

Increased Thrombin-Activatable Fibrinolysis Inhibitor in Response to Sublingual Immunotherapy for Allergic Rhinitis

OBJECTIVES/HYPOTHESIS

The objective of this study was to determine the role of thrombin-activatable fibrinolysis inhibitor (TAFI) as a candidate biomarker for therapeutic efficacy of sublingual immunotherapy (SLIT) and to identify the role of TAFI in the pathogenesis of allergic rhinitis (AR).

STUDY DESIGN

Retrospective cohort study and laboratory study.

METHODS

Serum was collected from patients with allergies to Japanese cedar pollen before, during, and after treatment with SLIT. We measured the levels of immunoreactive TAFI, C3a, and C5a in serum by enzyme-linked immunosorbent assay (ELISA) and assessed their relative impact on a combined symptom-medication score. We also examined the impact of TAFI on mast cells and fibroblasts in experiments performed in vitro.

RESULTS

Serum levels of TAFI increased significantly in response to SLIT. By contrast, serum C3a levels decreased significantly over time; we observed a significant negative correlation between serum levels of TAFI versus C3a and symptom-medication score. Mast cell degranulation was inhibited in response to TAFI, as it was the expression of both CCL11 and CCL5 in cultured fibroblasts.

CONCLUSIONS

High serum levels of TAFI may be induced by SLIT. TAFI may play a critical protective role in pathogenesis of AR by inactivating C3a and by inhibiting mast cell degranulation and chemokines expression in fibroblasts.

LEVEL OF EVIDENCE

4 Laryngoscope, 2021.

A Phase II, Multicenter, Randomized, Placebo-Controlled Study of Benralizumab, a Humanized Anti-IL-5R Alpha Monoclonal Antibody, in Patients With Eosinophilic Chronic Rhinosinusitis

BACKGROUND

Strong eosinophil infiltration in chronic rhinosinusitis with nasal polyp (CRSwNP) is highly associated with recalcitrance and higher nasal polyp recurrence rate after surgery. The prevalence of eosinophilic CRSwNP (ECRS) is increasing in Asian countries including Japan. Benralizumab is a humanized anti-IL-5R alpha monoclonal antibody that depletes eosinophils by antibody-dependent cell-mediated cytotoxicity.

OBJECTIVE

To assess the efficacy and safety of benralizumab in patients with ECRS.

METHODS

This phase II, randomized, double-blind, placebo-controlled study was conducted in Japan. Patients were randomized 1:2:2 to placebo, a single administration of benralizumab 30 mg, or benralizumab 30 mg every 4 weeks (q4w) for a total of three doses. The primary endpoint was the change in nasal polyp score from baseline at Week 12.

RESULTS

Overall, 56 patients were enrolled (placebo, n = 11; benralizumab single dose, n = 22; benralizumab q4w, n = 23). Although the mean total nasal polyp score began to decrease after the initiation of benralizumab treatment, there were no statistically significant differences in change in nasal polyp score from baseline at Week 12 between benralizumab and placebo (placebo, -0.5 ± 0.8; benralizumab single, -0.3 ± 0.8; benralizumab q4w, -0.5 ± 1.5). Post-hoc analysis showed that the administration of benralizumab decreased nasal polyp scores ≥2 points in 42.2% of ECRS patients and that patients with high blood eosinophil levels had a greater tendency to respond to benralizumab treatment. The safety profile was similar to that in previous studies and no unexpected adverse events were noted.

CONCLUSION

Although benralizumab did not meet the primary efficacy endpoint, reductions of nasal polyp scores were seen in the benralizumab group compared with the placebo group over the whole study period, especially in patients with high levels of blood eosinophils.

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.

Baicalin suppresses type 2 immunity through breaking off the interplay between mast cell and airway epithelial cell

ETHNOPHARMACOLOGICAL RELEVANCE

The traditional Japanese herbal medicine Shin'iseihaito was reported to ameliorate the airway type 2 inflammatory response in clinical and experimental studies. Airway type 2 inflammatory diseases, including bronchial asthma and eosinophilic chronic rhinosinusitis (ECRS), often coexist and interact with each other. However, it is still unclear how Shin'iseihaito exerts its pharmacological effects on cells involved in airway mucosa.

AIM OF THE STUDY

This study aims to examine the direct effect of baicalin, a representative bioactive compound of Shin'iseihaito, on type 2 immune responses in human airway epithelial cells and mast cells.

MATERIAL AND METHODS

We measured the plasma pharmacokinetics of flavonoids derived from Shin'iseihaito and investigated the effects of baicalin on type 2 immune responses in human airway epithelial cells and human mast cells.

RESULTS

Baicalin, wogonin, and wogonoside were detected in the plasma. The maximum plasma concentration of baicalin was highest at 1610 ng/ml (3.6 μM). In the normal human bronchial epithelial cells treated with baicalin, with or without stimulation by IFN-γ, the IL-33 expression was significantly downregulated. However, baicalin treatment did not affect the levels of thymic stromal lymphopoietin and IL-25. We noted that IL-33-dependent expression of tryptase mRNA in mast cells was significantly inhibited by baicalin. Also, the expression of IL-5 in mast cells enhanced by stimulation with TSLP plus IL-1β was significantly downregulated by baicalin treatment. Moreover, the enhancement of IL-13 expression in mast cells by IL-33 simulation was also significantly inhibited by baicalin.

CONCLUSIONS

Our results prove that by breaking off the vicious circle of mast cells and airway epithelial cells, baicalin may be an effective alternative therapeutic option for the treatment of type 2 inflammatory diseases, such as ECRS and comorbid asthma.

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.

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.

The Effect of Dupilumab on Intractable Chronic Rhinosinusitis with Nasal Polyps in Japan

Objectives/Hypothesis

Dupilumab, which blocks the shared receptor component for interleukin‐4 and interleukin‐13, reduced polyp size, sinus opacification, and symptom severity, and was well tolerated in patients with chronic rhinosinusitis with nasal polyps (CRSwNP) in the SINUS‐52 study (NCT02898454). We assessed dupilumab in patients enrolled at Japanese centers.

Methods

Patients on a background of mometasone furoate nasal spray, received dupilumab 300 mg every 2 weeks (q2w) for 52 weeks (Arm A); dupilumab 300 mg q2w for 24 weeks, followed by every 4 weeks (q4w) for 28 weeks (Arm B); or placebo (Arm C). Co‐primary endpoints were week 24 nasal polyp score (NPS), nasal congestion (NC) score, and sinus Lund–Mackay CT (LMK‐CT) scores. Symptoms, sense of smell, health‐related quality of life, and safety were assessed during the 52‐week treatment period.

Results

Of 49 patients enrolled in Japan, 45 completed the study. Week 24 least squares (LS) mean improvement versus placebo were as follows: NPS (Arm A: −3.1, P < .0001; Arm B: −2.1, P = .0011); NC score (Arm A: −1.2, P < .0001; Arm B: −0.9, P < .0001); and LMK‐CT (Arm A: −5.1, P = .0005; Arm B: −2.8, P = .0425). The most common treatment‐emergent adverse event in dupilumab and placebo‐treated patients was nasopharyngitis.

Conclusion

Dupilumab provided rapid, significant, and clinically meaningful improvements for patients with CRSwNP in Japan. Dupilumab was well tolerated, and safety and efficacy were consistent with the overall study population.

Level of Evidence

2 Laryngoscope, 131:E1770–E1777, 2021

Enhanced 15-Lipoxygenase 1 Production is Related to Periostin Expression and Eosinophil Recruitment in Eosinophilic Chronic Rhinosinusitis

BACKGROUND

The pathological features of chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP) tissues include an eosinophilic infiltration pattern (eosinophilic CRS (ECRS)) or a less eosinophilic pattern (non-ECRS). Recently, it has been suggested that 15-lipoxygenase 1 (15-LOX-1) may have significant roles in allergic disease; however, the significance of 15-LOX-1 in CRS is not well understood. The objective of this study was to demonstrate the expression of 15-LOX-1 in CRS.

METHODS

The mRNA expression levels of 15-LOX-1 and periostin in nasal tissues were measured by quantitative real-time polymerase chain reaction. We also performed an immunofluorescence study of nasal tissues. Cells of the Eol-1 eosinophilic leukemic cell line were stimulated with interleukin-33 to test the induction of 15-LOX-1.

RESULTS

The expression level of 15-LOX-1 mRNA in nasal polyps (NPs) was significantly higher in ECRS patients than in non-ECRS patients. The immunofluorescence study revealed that both airway epithelial cells and eosinophils in NPs expressed 15-LOX-1. A significant correlation was seen between the number of eosinophils and the mRNA expression levels of 15-LOX-1 and periostin in nasal polyps. Moreover, interleukin-33 enhanced 15-LOX-1 expression in Eol-1 cells.

CONCLUSIONS

15-LOX-1 was shown to be a significant molecule that facilitates eosinophilic inflammation in ECRS.

Strategic Outlook toward 2030: Japan's research for allergy and immunology - Secondary publication

Strategic Outlook toward 2030: Japan's Research for Allergy and Immunology (Strategy 2030) is the national research strategy based on Japan's Basic Law on Measures Against Allergic Diseases, a first of its kind worldwide. This strategy was established by a multi-disciplinary committee consisting of administrators of the Ministry of Health, Labour and Welfare of Japan, young and senior experts from various research societies and associations, and representatives of patient and public groups. Whereas the issues of transition, integration, and international collaboration have yet to be solved in this research realm in Japan, identification of unmet needs, digitization of information and transparent procedures, and strategic planning for complex problems (a process dubbed MIERUKA by the Toyota Way) are crucial to share and tackle the same vision and goals. The committee developed three specific actions focusing on preemptive treatment, interdisciplinarity and internationality, and life stage. The real success of Strategy 2030 is made by the spontaneous contributions of doctors, dentists, veterinarians, and other medical professionals; basic and clinical research scientists, research supporters, and pharmaceutical/medical device companies; manufacturers of food, healthcare, and home appliances; and patients, their families, and the public. The hope is to establish a stable society in which people can live long, healthy lives, as free as possible from allergic and immunological diseases, at each individual life stage. This article is based on a Japanese review first reported in Arerugi, introduces the developmental process and details of Strategy 2030.

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.

Epidemiological study of oral allergy syndrome in birch pollen dispersal-free regions

BACKGROUND

Oral allergy syndrome (OAS) is an immediate allergy caused by a cross-reaction of highly homologous common antigens (pan-allergens) contained in fruits/vegetables and pollen.

METHODS

A questionnaire was provided to 6824 outpatient visitors and serum levels of specific IgEs against crude antigens and pan-allergen components were measured to study the relationship between the prevalence of OAS and pollinosis in the Fukui Prefecture where there is almost no dispersal of birch pollen.

RESULTS

The prevalence of OAS was 10.8%. The rate of pollinosis complication in the OAS group was 67.4%, and OAS was observed in 16.8% of pollinosis patients. Causative foods in order of frequency were melon, pineapple, kiwi fruit, peach, and apple. A significantly higher number of patients from the OAS group were positive for birch, alder, and timothy grass-specific IgE. The rate of positivity for anti-component IgE corresponding to pollen in OAS group was also significantly higher. Of 34 patients with OAS caused by eating apples, 28 (82.4%) were positive for Mal d1-specific IgE. Of the 52 patients with peach-induced OAS, 41 (78.8%) were positive for Pur p1-specific IgE. The concordance rates between crude antigen-specific IgE and anti-PR-10 component-specific IgE were 87.1% and 93.3% for apple and peach respectively.

CONCLUSIONS

In regions where birch pollen is not dispersed, OAS patients have a significant association with the onset of Bet v1-associated allergy. Anti-PR-10 component IgE was useful in diagnosing OAS, and crude antigen-specific IgE was also associated with apple and peach allergies.

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.

Galectin-10, the protein that forms Charcot-Leyden crystals, is not stored in granules but resides in the peripheral cytoplasm of human eosinophils

A predominant protein of human eosinophils is galectin-10 (Gal-10), also known as Charcot-Leyden crystal protein (CLC-P) because of its remarkable ability to form Charcot-Leyden crystals (CLCs), which are frequently found in tissues from patients with eosinophilic disorders. CLC-P/Gal-10 is highly expressed in human eosinophils and considered a biomarker of eosinophil involvement in inflammation. However, the intracellular sites where large pools of CLC-P/Gal-10 constitutively reside are still unclear, and whether this protein is derived or not from eosinophil granules remains to be established. Here, we applied pre-embedding immunonanogold transmission electron microscopy combined with strategies for optimal antigen and cell preservation and quantitative imaging analysis to investigate, for the first time, the intracellular localization of CLC-P/Gal-10 at high resolution in resting and activated human eosinophils. We demonstrated that CLC-P/Gal-10 is mostly stored in the peripheral cytoplasm of human eosinophils, being accumulated within an area of ∼250 nm wide underneath the plasma membrane and not within specific (secretory) granules, a pattern also observed by immunofluorescence. High-resolution analysis of single cells revealed that CLC-P/Gal-10 interacts with the plasma membrane with immunoreactive microdomains of high CLC-P/Gal-10 density being found in ∼60% of the membrane area. Eosinophil stimulation with CCL11 or TNF-α, which are known inducers of eosinophil secretion, did not change the peripheral localization of CLC-P/Gal-10 as observed by both immunofluorescence and immuno-EM (electron microscopy). Thus, in contrast to other preformed eosinophil proteins, CLC-P/Gal-10 neither is stored within secretory granules nor exported through classical degranulation mechanisms (piecemeal degranulation and compound exocytosis).