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.

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.

Optical coherence tomography analysis of late lumen enlargement after paclitaxel-coated balloon angioplasty for de-novo coronary artery disease.

BACKGROUND: Paclitaxel-coated balloon angioplasty for de-novo coronary artery lesions causes late lumen enlargement (LLE), however, the mechanisms and predictors of LLE have not been elucidated. METHODS AND RESULTS: We retrospectively analyzed 91 consecutive patients with 95 de-novo coronary lesions, who underwent paclitaxel-coated balloon angioplasty without stenting from August 2018 to July 2019 as well as follow-up coronary angiography and optical coherence tomography (OCT). The mean follow-up duration was 8.2 ± 2.9 months. The target lesion revascularization rate was 7.3%. OCT demonstrated LLE in 50.5% of lesions. The lesions with LLE had a higher incidence of vessel enlargement (76.6 vs. 29.2%, p < .01), regression of plaque or dissection flap (55.3 vs. 10.4%, p < 0.01; 40.4 vs. 14.6%, p < .01, respectively), and reattachment and healing of dissection flaps (74.5 vs. 27.1%, p < .01) compared with those without LLE. Preprocedure thick-cap fibroatheroma plaques and postprocedure deep dissection reaching the tunica media were positive predictors of LLE (hazard ratio, HR 3.74 [1.93-7.25], p < .001; HR 2.04 [1.02-4.05], p < .05, respectively). CONCLUSIONS: OCT analysis after paclitaxel-coated balloon treatment of de-novo coronary artery lesions revealed that the mechanism of LLE was associated with vessel enlargement, healing of dissection flaps, and regression of plaque or dissection flap. Preprocedure thick-cap fibroatheroma plaques and postprocedure deep dissection reaching the tunica media on OCT were predictors of LLE.

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.

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.

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.

Eosinophilic chronic rhinosinusitis.

Eosinophilic chronic rhinosinusitis (ECRS) is a subgroup of chronic rhinosinusitis with nasal polyps (CRSwNP), which is associated with severe eosinophilic infiltration and intractable. Its symptoms include dysosmia, nasal obstruction, and visous nasal discharge. The cause of ECRS is not clear, although it is thought that Staphylococcus aureus and its enterotoxins are involved in stimulating the Th2 system to promote IgE production and eosinophil infiltration through various pathways. While, the coagulation system is activated and the fibrinolytic system is suppressed, leading to deposition of fibrinous networks in nasal polyps. Therefore, a fibrin-degrading agent could be a new treatment for ECRS. Genetic analysis of nasal polyp cells using next-generation sequencing has identified some of the factors involved in ECRS, including periostin, which can be used as a biomarker of this condition. A protease inhibitor could be a therapeutic agent for ECRS. Regarding the role of eosinophils, many researchers have been interested in the mechanism of ETosis. However, the mechanism leading to development of nasal polyps is unknown. In Japan (as well as in East Asia), the incidence of non-ECRS is decreasing and that of ECRS is increasing, but the reason is also unknown. Thanks to the development of biologics therapy, it is thought that there will be a shift to precision medicine in the future.

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.

Murine allergic rhinitis and nasal Th2 activation are mediated via TSLP- and IL-33-signaling pathways.

Thymic stromal lymphopoietin (TSLP) and IL-33 are epithelium-derived proallergic cytokines that contribute to allergic diseases. Although the involvement of TSLP in allergic rhinitis (AR) is suggested, the exact role of TSLP in AR is poorly understood. Furthermore, the relative contribution of TSLP and IL-33 in nasal allergic responses has not been described. In this study, we examined the roles of TSLP and IL-33 in AR by analyzing acute and chronic AR models. Acute AR mice were intraperitoneally immunized with ragweed, then intranasally challenged with ragweed pollen for four consecutive days. Chronic AR mice were nasally administrated ragweed pollen on consecutive days for 3 weeks. In both models, TSLP receptor (TSLPR)-deficient mice showed defective sneezing responses and reduced serum ragweed-specific IgE levels compared with wild-type (WT) mice. Analyses of bone-marrow chimeric mice demonstrated that hematopoietic cells were responsible for defective sneezing in TSLPR-deficient mice. In addition, FcεRI(+)-cell-specific TSLPR-deficient mice showed partial but significant reduction in sneezing responses. Of note, Th2 activation and nasal eosinophilia were comparable between WT and TSLPR-deficient mice. ST2- and IL-33-deficient mice showed defective Th2 activation and nasal eosinophilia to acute, but not chronic, ragweed exposure. TSLPR and ST2 double-deficient mice showed defective Th2 activation and nasal eosinophilia even after chronic ragweed exposure. These results demonstrate that TSLPR signaling is critical for the early phase response of AR by controlling the IgE-mast-cell/basophil pathway. The IL-33/ST2 pathway is central to nasal Th2 activation during acute allergen exposure, but both TSLPR and ST2 contribute to Th2 responses in chronically allergen-exposed mice.

The significant expression of TRPV3 in nasal polyps of eosinophilic chronic rhinosinusitis.

BACKGROUND: The number of patients with eosinophilic chronic rhinosinusitis (ECRS) has been increasing in recent years in Japan. In ECRS, nasal polyps recur immediately after endoscopic sinus surgery. The molecular biological mechanism underlying the refractoriness of ECRS is unclear. METHODS: Whole-transcriptome analysis with next-generation sequencing (RNA-seq) was conducted to investigate the molecular biological mechanism of ECRS. Real-time PCR, immunohistochemical staining, and immunofluorescence staining were performed to validate the results of RNA-seq. RESULTS: RNA-seq analysis revealed that in the nasal polyps of ECRS, the levels of 3 transcripts were elevated significantly and those of 7 transcripts were diminished significantly. Among the genes encoding these transcripts, TRPV3 (transient receptor potential cation channel, subfamily V, member 3) was identified as the only gene that is highly expressed in ECRS nasal polyps but this gene's expression was not previously detected using DNA microarray analysis in peripheral blood eosinophils. TRPV3 is newly identified here as a gene transcribed in ECRS. Our analysis also revealed that TRPV3 was highly expressed in the infiltrating eosinophils and mucosal epithelium of the nasal polyps of ECRS, and further that the more severe the refractoriness was after surgery, the higher the TRPV3 expression was in nasal polyps. CONCLUSIONS: TRPV3 might play a role in the refractoriness of ECRS. Additional studies are required to evaluate the function of TRPV3 in ECRS.

Nattokinase, profibrinolytic enzyme, effectively shrinks the nasal polyp tissue and decreases viscosity of mucus.

BACKGROUND: Chronic rhinosinusitis with nasal polyps (CRSwNP) is often comorbid with asthma and resistant to therapeutic interventions. We recently reported that excessive fibrin deposition caused by impairment of fibrinolysis might play pivotal role in forming nasal polyp. Nattokinase (NK), a serine protease produced by Bacillus subtilis, has been reported to be a strong fibrinolytic enzyme. NK could be a promising drug candidate for use in the treatment of both CRSwNP and asthma. The objective of this study was to investigate the effects of NK on nasal polyp tissues from patients with CRSwNP. The nasal discharge from patients with CRSwNP and sputum from subjects with asthma were also used to investigate whether NK influences the viscosity of mucus. METHODS: To examine the effects on NK on nasal polyp tissues, pieces of nasal polyps were incubated either with saline or NK (10-1000 FU/ml) at 37 °C for 24 h. We assessed the presence of fibrin in nasal polyp tissue incubated with NK by means of immunohistochemistry. To examine the effects of NK on nasal discharge and sputum from patients with CRSwNP and asthma, respectively, were incubated with NK solution at 37 °C for 1 h. RESULTS: NK effectively shrinks the nasal polyp tissue through fibrin degradation. We also found that the viscosity of the nasal discharge and sputum from patients with CRSwNP and asthma, respectively, was significantly reduced by incubation with NK solution. CONCLUSIONS: NK may be an effective alternative therapeutic option in patients with CRSwNP and comorbid asthma by causing fibrin degradation.

Proallergic cytokines and group 2 innate lymphoid cells in allergic nasal diseases.

Recent advances in our understanding of proallergic cytokines and group 2 innate lymphoid cells (ILC2s) indicate their critical roles in type 2 immunity-mediated disorders. Proallergic cytokines, interleukin (IL)-25, IL-33, and thymic stromal lymphopoietin, are released from epithelial cells in inflamed tissues and drive type 2 inflammation by acting on innate and acquired immune systems. ILC2s are an innate immune population that responds to proallergic cytokines by producing type 2 cytokines. In line with allergic disorders in the lung, skin, and intestine, emerging evidence suggests the involvement of proallergic cytokines and ILC2s in allergic nasal diseases such as chronic rhinosinusitis with polyps (CRSwNP), allergic fungal rhinosinusitis, and allergic rhinitis (AR). In CRSwNP patients, both proallergic cytokine levels and ILC2s frequency are increased in the nasal mucosa. Increased proallergic cytokine levels correlate with poorer disease outcomes in CRSwNP. Levels of nasal proallergic cytokines are also elevated in AR patients. In addition, animal studies demonstrate that cytokines are essential for the development of AR. It is becoming clear that the proallergic cytokine/ILC2s axis participates in allergic diseases by multiple mechanisms dependent upon the inflammatory context. Thus, a thorough understanding of these cytokines and ILC2s including their tissue- and disease-specific roles is essential for targeting the pathways to achieve therapeutic applications.

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.

Long-term compliance with nasal continuous positive airway pressure therapy for sleep apnea syndrome in an otorhinolaryngological office.

Continuous positive airway pressure (CPAP) is effective for patients with SAS. CPAP therapy requires long-term usage to prevent recurrence of symptoms. It is, thus, important to examine the level of long-term CPAP use and the factors influencing compliance with CPAP therapy for SAS. Compliance with CPAP therapy was examined in 204 patients in whom such therapy was started between 2003 and 2009. The median follow-up duration was 19 months (IQR = 6.8-37.5). Although the subjective and objective curative effects were significant, 18 patients (8.9%) refused CPAP therapy. Survival analysis showed that the patients' adherence to CPAP after 5 years was 89.8%. Multivariate analysis, including gender, age, BMI, AHI, arousal index, minSpO2, ESS, sleep stage, and LMI, indicated that the degree of improvement of AHI, percentage of deep sleep stage, and LMI were clinical variables independently associated with long-term adherence to CPAP. Furthermore, use of appropriate drugs for the patients with nasal congestion resulted in better satisfaction and adherence to CPAP therapy. We have shown that the rate of compliance and the subjective and objective curative effects of CPAP therapy were high, and detected the independent clinical factors associated with continued CPAP therapy.

Impella-Supported Optical Coherence Tomography-Guided Aggressive Rotational Atherectomy for Heavily Calcified Lesions in Left Main Trunk Bifurcation in a Patient with Severe Left Ventricular Systolic Dysfunction.

The Impella, a percutaneous left ventricular assist device, has been reported to minimize the risk of hemodynamic compromise and improve clinical outcomes during percutaneous coronary intervention (PCI) in complex high-risk indicated patients (CHIPs). Optical coherence tomography (OCT) provides information on calcified plaque thickness, which is helpful in determining the indication and endpoint of atherectomy during PCI for calcified lesions. However, there are few reports on OCT-guided aggressive rotational atherectomy with Impella assistance in CHIPs. A 71-year-old man on dialysis for end-stage renal failure was admitted for congestive heart failure. Transthoracic echocardiography revealed severe left ventricular systolic dysfunction, and coronary angiography performed after improvement of heart failure showed severe stenosis with heavily calcified lesions in the left main trunk (LMT) bifurcation and right coronary artery. The patient refused coronary artery bypass surgery and was revascularized using PCI. PCI was started with prophylactic Impella CP insertion because of the high risk of hemodynamic collapse. After OCT-guided rotational atherectomy with 1.5- and 2.0-mm burr toward the left anterior descending artery and left circumflex artery, respectively, double-kissing culotte stenting was performed in the LMT, and good dilation was obtained. Impella CP was removed immediately after PCI without hemodynamic compromise, and the procedure was completed.

Effects of aromatase or estrogen receptor gene deletion on masculinization of the principal nucleus of the bed nucleus of the stria terminalis of mice.

The principal nucleus of the bed nucleus of the stria terminalis (BNSTp) is a sexually dimorphic nucleus, and the male BNSTp is larger and has more neurons than the female BNSTp. To assess the roles of neuroestrogen synthesized from testicular androgen by brain aromatase in masculinization of the BNSTp, we performed morphometrical analyses of the adult BNSTp in aromatase knockout (ArKO), estrogen receptor-α knockout (αERKO), and estrogen receptor-ß knockout (ßERKO) mice and their respective wild-type littermates. In wild-type littermates, the BNSTp of males had a larger volume and greater numbers of neuronal and glial cells than did that of females. The volume and neuron number of the BNSTp in ArKO and αERKO males and glial cell number of the BNSTp in αERKO males were significantly smaller than those of wild-type male littermates, and they were not significantly different from those in female mice with either gene knockout. In contrast, there was no significant morphological difference in the BNSTp between ßERKO and wild-type mice. Next, we examined the BNSTp of ArKO males subcutaneously injected with estradiol benzoate (EB) on postnatal days 1, 2, and 3 (1.5 µg/day). EB-treated ArKO males had a significantly greater number of BNSTp neurons than did oil-treated ArKO males. The number of BNSTp neurons in EB-treated ArKO males was comparable to that in wild-type males. These findings suggested that masculinization of the BNSTp in mice involves the actions of neuroestrogen that was synthesized by aromatase and that this estrogen mostly binds to ERα during the postnatal period.

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, 131:2413-2420, 2021.

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-1ß 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.

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.