New insights into chronic rhinosinusitis associated with IgG4-related disease

IgG4-related disease (IgG4-RD) is a chronic inflammatory disorder characterized by elevated IgG4 serum levels, abundant IgG4-positive plasmacyte infiltration, and fibrosis of various organs, including the head and neck. We aimed to provide an overall review of IgG4-RD in the sinonasal region and propose a novel entity and criteria of chronic rhinosinusitis (CRS) associated with IgG4-RD as "IgG4-CRS," a distinct manifestation of IgG4-RD in the sinonasal region. Sinonasal involvement has been increasingly recognized; however, this region is not included in the classic IgG4-RD-affected organs. The clinical features of IgG4-CRS, including its prevalence and relationship with allergies and olfactory disturbances, have also been explored. Serum IgG4 levels and IgG4-positive plasma cell infiltrations, crucial diagnostic factors, have been discussed in association with IgG4-CRS pathogenesis. Fibrosis, a hallmark of IgG4-RD, is observed in sinonasal tissues; however, typical fibrosis, such as storiform fibrosis, is not usually found. Mimics or complications in eosinophilic CRS (ECRS) and antineutrophil cytoplasmic antibody-associated vasculitis (AAV) are highlighted. Treatment often involves typically effective glucocorticoids. Organ-specific diagnostic criteria for the sinonasal region have not currently been established. Hence, this review aims to foster awareness and understanding of IgG4-CRS among ENT physicians and to provide a basis for future research and diagnostic refinement.

C-C Motif Chemokine Receptor 3-Mediated Extracellular Signal-Regulated Kinase 1/2 and p38 Mitogen-Activated Protein Kinase Signaling: Promising Targets for Human Airway Epithelial Mucin 5AC Induction by Eotaxin-2 and Eotaxin-3

INTRODUCTION

Eotaxin-2 and -3 of the C-C chemokine subfamily function as potent chemoattractant factors for eosinophil recruitment and various immune responses in allergic and inflammatory airway diseases. Mucin 5AC (MUC5AC), a major gel-forming secretory mucin, is overexpressed in airway inflammation. However, the association between mucin secretion and eotaxin-2/3 expression in the upper and lower airway epithelial cells has not been fully elucidated. Therefore, in this study, we investigated the effects of eotaxin-2/3 on MUC5AC expression and its potential signaling mediators.

METHODS

We analyzed the effects of eotaxin-2 and -3 on NCI-H292 human airway epithelial cells and primary human nasal epithelial cells (HNEpCs) via reverse transcription-polymerase chain reaction, enzyme-linked immunosorbent assay, and western blotting. Along with immunoblot analyses with specific inhibitors and small interfering RNA (siRNA), we explored the signaling pathway involved in MUC5AC expression following eotaxin-2/3 treatment.

RESULTS

In HCI-H292 cells, eotaxin-2/3 activated the mRNA expression and protein production of MUC5AC. A specific inhibitor of C-C motif chemokine receptor 3 (CCR3), SB328437, suppressed eotaxin-2/3-induced MUC5AC expression at both the mRNA and protein levels. Eotaxin-2/3 induced the phosphorylation of extracellular signal-regulated kinase (ERK)-1/2 and p38, whereas pretreatment with a CCR3 inhibitor significantly attenuated this effect. Induction of MUC5AC expression with eotaxin-2/3 was decreased by U0126 and SB203580, specific inhibitors of ERK1/2 and p38 mitogen-activated protein kinase (MAPK), respectively. In addition, cell transfection with ERK1/2 and p38 siRNAs inhibited eotaxin-2/3-induced MUC5AC expression. Moreover, specific inhibitors (SB328437, U0126, and SB203580) attenuated eotaxin-2/3-induced MUC5AC expression in HNEpCs.

CONCLUSION

Our results imply that CCR3-mediated ERK1/2 and p38 MAPK are involved in the signal transduction of eotaxin-2/3-induced MUC5AC overexpression.

Involvement of CD40-CD40L and ICOS-ICOSL in the development of chronic rhinosinusitis by targeting eosinophils

Background

Chronic rhinosinusitis (CRS), whose prevalence and pathogenesis are age-related, is characterized by nasal tissue eosinophil infiltration. CD40-CD40 ligand (CD40L) pathway involves in the eosinophil-mediated inflammation, and inducible co-stimulator (ICOS)-ICOS ligand (ICOSL) signal can strengthen CD40-CD40L interaction. Whether CD40-CD40L and ICOS-ICOSL have a role in the development of CRS remains unknown.

Objectives

The aim of this study is to investigate the association of CD40-CD40L and ICOS-ICOSL expression with CRS and underlying mechanisms.

Methods

Immunohistology detected the expression of CD40, CD40L, ICOS, and ICOSL. Immunofluorescence was performed to evaluate the co-localizations of CD40 or ICOSL with eosinophils. Correlations between CD40-CD40L and ICOS-ICOSL as well as clinical parameters were analyzed. Flow cytometry was used to explore the activation of eosinophils by CD69 expression and the CD40 and ICOSL expression on eosinophils.

Results

Compared with the non-eCRS subset, ECRS (eosinophilic CRS) subset showed significantly increased CD40, ICOS, and ICOSL expression. The CD40, CD40L, ICOS, and ICOSL expressions were all positively correlated with eosinophil infiltration in nasal tissues. CD40 and ICOSL were mainly expressed on eosinophils. ICOS expression was significantly correlated with the expression of CD40-CD40L, whereas ICOSL expression was correlated with CD40 expression. ICOS-ICOSL expression positively correlated with blood eosinophils count and disease severity. rhCD40L and rhICOS significantly enhanced the activation of eosinophils from patients with ECRS. Tumor necrosis factor-α (TNF-α) and interleukin-5 (IL-5) obviously upregulated CD40 expression on eosinophils, which was significantly inhibited by the p38 mitogen-activated protein kinase (MAPK) inhibitor.

Conclusions

Increased CD40-CD40L and ICOS-ICOSL expressions in nasal tissues are linked to eosinophils infiltration and disease severity of CRS. CD40-CD40L and ICOS-ICOSL signals enhance eosinophils activation of ECRS. TNF-α and IL-5 regulate eosinophils function by increasing CD40 expression partly via p38 MAPK activation in patients with CRS.

Immunopathologic Role of Eosinophils in Eosinophilic Chronic Rhinosinusitis

Chronic rhinosinusitis (CRS) is a diverse chronic inflammatory disease of the sinonasal mucosa. CRS manifests itself in a variety of clinical and immunologic patterns. The histological hallmark of eosinophilic CRS (ECRS) is eosinophil infiltration. ECRS is associated with severe disease severity, increased comorbidity, and a higher recurrence rate, as well as thick mucus production. Eosinophils play an important role in these ECRS clinical characteristics. Eosinophils are multipotential effector cells that contribute to host defense against nonphagocytable pathogens, as well as allergic and nonallergic inflammatory diseases. Eosinophils interact with Staphylococcus aureus, Staphylococcal enterotoxin B, and fungi, all of which were found in the tissue of CRS patients. These interactions activate Th2 immune responses in the sinonasal mucosa and exacerbate local inflammation. Activated eosinophils were discovered not only in the tissue but also in the sinonasal cavity secretion. Eosinophil extracellular traps (EETs) are extracellular microbes trapping and killing structures found in the secretions of CRS patients with intact granule protein and filamentous chromatic structures. At the same time, EET has a negative effect by causing an epithelial barrier defect. Eosinophils also influence the local tissue microenvironment by exchanging signals with other immune cells and structural cells. As a result, eosinophils are multifaceted leukocytes that contribute to various physiologic and pathologic processes of the upper respiratory mucosal immune system. The goal of this review is to summarize recent research on the immunopathologic properties and immunologic role of eosinophils in CRS.

Clinical Evaluation of Sinonasal Lesions in Patients With Immunoglobulin G4-Related Disease

Objectives:

Immunoglobulin G4-related disease (IgG4-RD) is a systemic disease entity characterized by elevated serum IgG4 and extensive IgG4-positive plasma cell infiltration of various organs. Patients with IgG4-RD show nasal manifestations with chronic rhinosinusitis. The objective of this study was to evaluate the clinical characteristics of sinonasal lesions in patients with IgG4-RD.

Methods:

We evaluated radiological findings of sinonasal lesions in 79 patients with IgG4-RD who were divided into 3 groups according to severity. We also compared serological findings, including serum IgG4 and IgE levels, and eosinophil counts.

Results:

Rhinosinusitis was found in 41 patients (51.9%). Although there were no significant differences in the serum IgG4 and IgE levels of the groups, there was a significant increase in eosinophil counts (445 ± 311.9/mm3) in Group C. Furthermore, 14 of the 41 patients with rhinosinusitis (34.1%) showed improvement after prednisolone administration. Patients with IgG4-RD and serum eosinophilia tend to also have sinonasal lesions.

Conclusions:

Rhinosinusitis is common in patients with IgG4-RD, and its pathogenesis can be similar to eosinophilic chronic rhinosinusitis.

Nasal fluid release of eotaxin-3 and eotaxin-2 in persistent sinonasal eosinophilic inflammation

BACKGROUND

The aim of the present study was to measure eotaxin-3 (CCL26) and eotaxin-2 (CCL24) in nasal lavage fluid of patients with different forms of chronic sinonasal eosinophilic inflammation to evaluate their role in the pathophysiology of nasal hypereosinophilia.

METHODS

The study was an analytic cross-section study, level of evidence 3b. Patients (n = 80) with nasal hypereosinophilia were randomly recruited and grouped in the following categories: persistent allergic rhinitis (AR) (n = 25), nonallergic rhinitis with eosinophilia syndrome (NARES) (n = 30), and chronic rhinosinusitis with polyps (CRSwNP) (n = 25). Non-rhinitic volunteers (n = 20) were recruited as controls. CCL24 and CCL26 concentrations were measured by enzyme-linked immunosorbent assay (ELISA) Quantikine Human Immunoassays (R&D Systems, Minneapolis, MN) in nasal lavage fluids. Differential cell counts were performed by microscopic cytological examination of nasal tissue scraped from the inferior turbinate.

RESULTS

Mean CCL26 levels were significantly higher (p < 0.05) in AR and in NARES (132.0 pg/mL and 187.63 pg/mL, respectively) than in the control group (13.5 pg/mL); in patients with CRSwNP, CCL26 values were increased compared to controls even though the difference was not statistically significant (58.9 pg/mL vs 16.5 pg/mL). Mean CCL24 levels measured in AR, NARES, and CRSwNP were significantly increased (p < 0.05) compared to controls (96.7 pg/mL, 135.4 pg/mL, and 107.0 pg/mL, respectively, vs 32.2 pg/mL). Moreover, we observed a significant correlation between CCL24 and CCL26 levels, evaluating them intraindividually by Spearman's rank correlation test. Finally, a significant correlation was found between CCL24 and CCL26 levels and the percentage of eosinophilic infiltration of nasal mucosa.

CONCLUSION

Our data suggest that CCL26 and CCL24 are likely involved in the pathogenesis of chronic nasal hypereosinophilia, with a complex cooperation and different involvement of the various members of eotaxin family. Further studies are necessary to better understand the actual physiopathologic mechanism, possible clinical relevance, and therapeutic implications.

Pathological mechanisms and clinical features of eosinophilic chronic rhinosinusitis in the Japanese population

The overall pathological view of paranasal sinus inflammation in the Japanese population has profoundly changed in recent years. Eosinophilic chronic rhinosinusitis (ECRS) is a clinical entity of intractable chronic sinus inflammation accompanied by numerous infiltrations of activated eosinophils in the paranasal sinus mucosa and/or nasal polyps. Several pathologic processes are considered to act in concert to promote the accumulation of eosinophils in ECRS. They include infiltration of progenitor cells, increase in local IL-3, IL-5, IL-13, GM-CSF and eotaxin production, and upregulation of adhesion molecules. The role of nasal allergen sensitization and innate immunity responses in the sinus mucosa has also been proposed in the development of ECRS. Various pathogens including TLRs ligands may trigger an abnormal immune response at the mucosal surface. The objectives of ECRS management should focus directly on inhibition of local eosinophil infiltration. Surgical procedures include widely opening the bony wall septum of every affected sinus and mechanical removal of diseased mucosal lesion. The use of local and/or systemic steroids, leukotriene receptor antagonists, and Th2 cytokine antagonists is recommended. Local administration of steroids is a potent treatment strategy for preventing relapse of nasal polyposis and is considered to be the first-line treatment for ECRS patients.

The effect of H1 antagonists carebastine and olopatadine on histamine induced expression of CC chemokines in cultured human nasal epithelial cells

BACKGROUND

CC chemokines have been shown to play an important role in inducing selective recruitment of inflammatory cells into local allergic inflammatory sites. CC chemokines are also known as histamine releasing factors. We previously showed that histamine enhances transcription of CC chemokines from nasal mucosa which leads to further induction of histamine release. This cyclic cascade may cause prolonged allergic inflammation. The aim of this study is to clarify the relationship between histamine and CC chemokine production by using human nasal epithelial cells (HNECs) and to examine the potential of H1 receptor (H1R) antagonists in new therapeutic approaches for the treatment of nasal allergy.

METHODS

HNECs were isolated from the nasal turbinates of patients diagnosed with nasal allergy. HNEC monolayers were cultured for 48 hours with or without histamine (10(-3) to 10(-5) mol/L). Furthermore, an H1R antagonist, either carebastine or olopatadine, was added to the supernatant (10(-3) to 10(-7) mol/L) 30 minutes before incubation with histamine. The expression of Regulated on Activation, Normal T-cell Expressed and Secreted (RANTES) and monocyte chemotactic protein-1 (MCP-1) in the culture media were measured by ELISA.

RESULTS

The release of RANTES and MCP-1 was significantly upregulated by histamine compared with the control group. Both carebastine and olopatadine inhibited the release of CC chemokine production to the control level in both groups.

CONCLUSIONS

This study suggests that the interaction between histamine and CC chemokines may prolong allergic inflammation in human nasal mucosa. We also demonstrate the potential use of H1R antagonists in new therapeutic approaches to the treatment of nasal allergy through inhibiting this histamine-CC chemokine interaction.

RANTES production from mononuclear cells in response to the specific allergen in asthma patients

BACKGROUND

Eosinophils are considered to be the major inflammatory cells in asthma. Since regulated on activation, normal T expressed and secreted (RANTES) is a potent chemoattractant for various important inflammatory cells such as eosinophils as well as memory T cells potentially recruiting these cells to an inflamed focus, RANTES has been considered to play a key role in various allergic disorders such as asthma.

METHODS

To extend our understanding of the participation of eosinophils and T cells in relation to the production of RANTES in response to the specific allergen in asthma, we examined the production of RANTES from peripheral blood mononuclear cells cultured with specific allergen in atopic asthma patients by a sandwich enzyme-linked immunosorbent assay.

RESULTS

It was revealed that mononuclear cells produced RANTES but not eotaxin in response to the specific allergen in asthma. RANTES production from mononuclear cells of asthma patients with eosinophilia was greater than that of asthma patients without eosinophilia. Moreover, in this study, no differences in RANTES production between CD4 negative cells and CD8 negative cells were observed.

CONCLUSIONS

Taken together, these findings may suggest that mononuclear cells play a crucial role in the pathogenesis, particular in eosinophil and T lymphocyte recruitment into the inflamed focus of asthma through RANTES production in response to the specific allergen.