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.

[STATE-OF-THE-ART OF GLOBAL START-UP INVESTMENT FOR ALLERGY AND IMMUNOLOGY 2022].

BACKGROUND: In 2022, the "New Capitalism Grand Design and Implementation Plan" was adopted in Japan, emphasizing the promotion and environmental development of startups. Given this context, an investigation into the startup and investment landscape in the allergy sector, both domestically and internationally, becomes imperative. METHODS: We analyzed 156 allergy-related startups from Japan, the US, and Europe from 2010 to 2021. Data on corporate information and investment trends were extracted from databases and VC websites. RESULTS: The total investment reached approximately 7.2 billion USD, with a ratio of 20:6:1 for the US, Europe, and Japan, respectively. The US showed a decline post its peak from 2016-2018, while Europe and Japan experienced growth. Notably, the US primarily invested in biopharmaceuticals for atopic dermatitis and food allergies, Europe in asthma-related apps, and Japan in healthcare apps and cross-border startups. DISCUSSION AND CONCLUSION: While Japan's investment environment in the allergy sector remains in its nascent stages and has room for development, the US and Europe are evidently ahead. Considering the rise of startups and funding limitations in Japan, external funding from regions like the US becomes a potential avenue. These findings are anticipated to contribute to the strategic activation of startups in allergy research and development.

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.

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.

Evaluation of adrenaline auto-injector prescription profiles: A population-based, retrospective cohort study within the National Insurance Claims Database of Japan.

BACKGROUND: Adrenaline is the first-line medication for managing anaphylaxis. A better understanding of prescription trends for adrenaline auto-injectors (AAIs) is important to improving patient care as well as information on health education interventions and medical guidelines. However, it has been difficult to gather comprehensive data in a sustainable manner. Thus, we aimed to investigate trends in AAI prescriptions in Japan. METHODS: We searched the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB), a unique and comprehensive database of health insurance claims, and investigated prescriptions for AAIs for all ages (April 2017 to March 2018). We assessed the annual number of prescriptions per person as well as prescription rates per 100,000 population per year by age, sex, and geographic region. RESULTS: A total of 88,039 subjects (56,109 males, 31,930 female) and 116,758 devices (1.33 AAIs per patient per year) were prescribed AAIs at least once a year for all ages. The prescription rate for AAIs was 69.5 per 100,000 population-years. Patients aged 0-9 years were prescribed AAIs at the rate of 278.9 per 100,000 population-years. Patients aged 0-19 years were 6.4 times more likely to be prescribed AAIs than those over 20 years of age. Males were more frequently prescribed AAIs than females in all age groups, except for those aged 20-24 years. We also evaluated differences in prescription rates by geographic region. CONCLUSIONS: This comprehensive evaluation revealed trends in AAI prescriptions, thus helping develop preventive strategies with respect to anaphylaxis in Japan.

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.

Serum IgG4 as a biomarker reflecting pathophysiology and post-operative recurrence in chronic rhinosinusitis.

BACKGROUND: Type 2 chronic rhinosinusitis (CRS), especially eosinophilic CRS (ECRS), is an intractable upper airway inflammatory disease. Establishment of serum biomarkers reflecting the pathophysiology of CRS is desirable in a clinical setting. As IgG4 production is regulated by type 2 cytokines, we sought to determine whether serum IgG4 levels can be used as a biomarker for CRS. METHODS: Association between the serum IgG4 levels and clinicopathological factors was analyzed in 336 CRS patients. Receiver operating characteristics (ROC) analysis was performed to determine the cut-off value of serum IgG4 levels that can be used to predict the post-operative recurrence. RESULTS: Serum IgG4 levels were significantly higher in patients with moderate to severe ECRS versus those with non to mild ECRS. The levels were also significantly higher in asthmatic patients and patients exhibiting recurrence after surgery compared to controls. ROC analysis determined that the best cut-off value for the serum IgG4 level to predict the post-operative recurrence was 95 mg/dL. The corresponding sensitivity and specificity were 39.7% and 80.5%, respectively. When we combined the two cut-off values for the serum IgG4 and periostin, patients with high serum levels of either IgG4 or periostin exhibited a high post-operative recurrence (OR: 3.95) as compared to patients having low serum levels of both IgG4 and periostin. CONCLUSIONS: The present results demonstrate that the serum IgG4 level is associated with disease severity and post-operative course in CRS. In particular, the combination of serum IgG4 and periostin could be a novel biomarker that predicts post-operative recurrence.

Safety profile and immunological response of dual sublingual immunotherapy with house dust mite tablet and Japanese cedar pollen tablet.

BACKGROUND: There have been no studies of dual administration of sublingual immunotherapy (SLIT) tablets for perennial and seasonal allergic rhinitis. This trial (JapicCTI-184014) was conducted to investigate the safety profile and immunological response during dual therapy with SQ house dust mite (HDM) and Japanese cedar pollen (JCP) SLIT tablets. METHODS: This was a multicenter, open-label, randomized trial of 109 Japanese patients with coexisting HDM and JCP allergic rhinitis who had positive tests for HDM- and JCP specific IgE (≥0.7 kU/L). Patients were allocated to receive HDM (N = 54) or JCP (N = 55) SLIT tablets alone for 4 weeks followed by 8 weeks of dual therapy with both SLIT tablets administered within 5 min of each other. Adverse events (AEs), adverse drug reactions (ADRs), and serum IgE and IgG4 specific for HDM (Dermatophagoides farinae, Dermatophagoides pteronyssinus) and JCP were recorded. RESULTS: The percentage of subjects with AEs and ADRs was similar between the two groups and between the two periods of monotherapy and dual therapy. Most AEs and ADRs were mild in severity, and no serious events were observed. The most common ADRs were local events in the oral cavity. Levels of IgE and IgG4 specific for HDM (D. farinae, D. pteronyssinus) and JCP were increased after treatment with HDM and JCP SLIT tablets, respectively. CONCLUSIONS: Dual therapy with both SLIT tablets administered within 5 min after 4 weeks of monotherapy with HDM or JCP tablet was well tolerated and induced the expected immunological responses.

Increased expression of L-plastin in nasal polyp of patients with nonsteroidal anti-inflammatory drug-exacerbated respiratory disease.

BACKGROUND: Most patients with nonsteroidal anti-inflammatory drug-exacerbated respiratory disease (NERD) suffer from recurrence of nasal polyps. However, little is known about the specific cellular and molecular mechanisms contributing to the pathogenesis of nasal polyp development in patients with NERD in particular, especially at baseline when cyclooxygenase 1 inhibitors are not present. The objectives of this study were to identify proteins involved in the pathogenesis of nasal polyps in patients with NERD. METHODS: We collected nasal polyp tissue from patients with NERD and from patients with aspirin-tolerant chronic rhinosinusitis with nasal polyps (CRSwNP). Protein profiles were analyzed by 2-dimensional electrophoresis and identified several proteins, including L-plastin, as highly expressed. We examined L-plastin and tissue factor (TF) expression by immunohistochemical and immunofluorescence analyses. To examine the role of L-plastin in eosinophils, we knocked down L-plastin expression in Eol-1 cells by using siRNA transfection. RESULTS: L-plastin protein levels in nasal polyp tissue were increased in patients with NERD relative to those in patients with aspirin tolerant CRSwNP. Immunofluorescence analysis revealed that L-plastin was dominantly expressed in eosinophils and L-plastin and TF were co-expressed in eosinophils in NERD nasal polyp tissue. Knockdown of L-plastin in Eol-1 cells disrupted the cell surface distribution of TF by stimulation with granulocyte macrophage colony-stimulating factor. CONCLUSION: Increased expression of L-plastin by eosinophils may contribute to abnormal fibrin deposition through TF translocation to the eosinophil cell surface in NERD nasal polyp tissue, which in turn may contribute to the pathogenesis of NERD.

Reduced nasal nitric oxide levels in patients with eosinophilic chronic rhinosinusitis.

BACKGROUND: In Eosinophilic chronic rhinosinusitis (ECRS), it is difficult to estimate the refractoriness and recurrence risk for each patient. Fraction of exhaled nitric oxide (FeNO) is known as a biomarker of eosinophilic inflammation in lower airway. It has been reported that nasal NO has some crucial functions in the upper and lower airways. However, in upper airway, paranasal sinuses, the usefulness of NO measurement remains controversial. The purpose of this study is to identify the usefulness of nasal NO measurement in ECRS and the involvement of nasal NO in the pathogenesis of ECRS. METHODS: We compared the nasal NO levels of ECRS, non-ECRS, and normal control groups. Correlation between nasal NO levels and clinical findings were observed. Then, we compared nasal NO levels before and after endoscopic sinus surgery (ESS). We also examine whether nasal NO levels might discriminate ECRS by the receiver operating characteristic (ROC) curve analysis. RESULTS: Nasal NO levels were significantly decreased in ECRS compared to the other two groups. Moreover, nasal NO levels in ECRS significantly and negatively correlated with eosinophil levels and CT score. However, they did not correlate with the nasal polyp score. Nasal NO levels were not upregulated soon after opening the sinus ostium by ESS. The ROC curves for nasal NO levels were used to discriminate all CRS patients and ECRS patients from normal controls. CONCLUSIONS: Nasal NO may be useful as a marker of ECRS severity and low nasal NO levels in ECRS may contribute to its pathogenesis.

Expression and Functional Analysis of CST1 in Intractable Nasal Polyps.

In this study, we found Cystatin SN (CST1), a type 2 cystatin subfamily member, to be highly expressed in nasal polyps from patients with intractable chronic rhinosinusitis (CRS) with nasal polyps, using a whole-transcript analysis with next-generation sequencing. Eosinophilic CRS (ECRS) involves nasal polyps that are refractory and recur immediately after endoscopic sinus surgery. We hypothesized that CST1 may contribute to the pathogenesis of ECRS. We examined the expression of CST1 in nasal polyps from patients with ECRS by assessing mRNA expression levels using real-time PCR and immunohistochemistry. CST1 showed significantly greater expression in the epithelial cells of nasal polyps from patients with ECRS than in those from patients who did not have ECRS (non-ECRS). In particular, CST1 showed very strong expression in patients with severe ECRS. The expression of CST1 may be correlated with the recurrent and refractory nature of ECRS. We examined the function of CST1 using nasal epithelial cells and nasal fibroblasts. Stimulation by a combination of IL-4 plus double-stranded RNA plus CST1 significantly elevated mRNA expression levels and protein levels of TSLP in nasal epithelial cells. Stimulation by TSLP or IL-33 significantly elevated mRNA expression levels of CST1 in nasal epithelial cells. Stimulation of CST1 significantly elevated mRNA expression levels of CCL11 and POSTN in nasal fibroblasts. CST1 could amplify eosinophilic infiltration and T-helper cell type 2 inflammation by interacting with epithelial-derived cytokines and fibroblasts on nasal polyps. CST1 may be involved in the pathogenesis of ECRS, and may contribute to the severity and recurrence of CRS with nasal polyps after endoscopic sinus surgery.

Potential Involvement of the Epidermal Growth Factor Receptor Ligand Epiregulin and Matrix Metalloproteinase-1 in Pathogenesis of Chronic Rhinosinusitis.

Chronic rhinosinusitis (CRS) is a heterogeneous chronic inflammatory disease of the nose and paranasal sinuses that presents without or with nasal polyps (CRSwNP). Notable features of CRSwNP are the frequent presence of type 2 allergic inflammation and high prevalence of Staphylococcus aureus (SA) colonization. As inflammation persists, sinus tissue undergoes epithelial damage and repair along with polyp growth, despite active medical management. Because one feature of damaged tissue is enhancement of growth factor signaling, we evaluated the presence of epidermal growth factor receptor (EGFR) ligands and matrix metalloproteinases (MMPs) in CRS. The objectives of this study were to analyze the expression of EGFR ligands and MMPs in patients with CRS and to investigate the possible role of SA on epithelial activation. Sinonasal tissues were collected during surgery from control subjects and patients with CRS. Tissues were processed as described previously for analysis of mRNA (RT-PCR) and proteins (ELISA) for the majority of EGFR ligands within the tissue extracts. CRS tissue was used for evaluation of the distribution of epiregulin (EREG), an EGFR ligand, and MMP-1 by immunohistochemistry. In parallel studies, expression of these genes and proteins was analyzed in cultured primary airway epithelial cells. Elevated expression of EREG and MMP-1 mRNA and protein was observed in uncinate and polyp tissue from patients with CRSwNP. Immunohistochemistry study of clinical samples revealed that airway epithelial cells expressed both of these proteins. Cultured primary human airway epithelial cells expressed MMP-1, and MMP-1 was further induced by stimulation with EREG or heat-killed SA (HKSA). The induction of MMP-1 by HKSA was blocked by an antibody against EREG, suggesting that endogenous EREG induces MMP-1 after stimulation with HKSA. EREG and MMP-1 were found to be elevated in nasal polyp and uncinate tissues in patients with CRSwNP. Elevated expression of EREG and MMP-1 may be related to polyp formation in CRS, and colonization of SA might further enhance this process.