COVID-19 treatments and pathogenesis including anosmia in K18-hACE2 mice.

The ongoing coronavirus disease 2019 (COVID-19) pandemic is associated with substantial morbidity and mortality. Although much has been learned in the first few months of the pandemic, many features of COVID-19 pathogenesis remain to be determined. For example, anosmia is a common presentation, and many patients with anosmia show no or only minor respiratory symptoms1. Studies in animals infected experimentally with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the cause of COVID-19, provide opportunities to study aspects of the disease that are not easily investigated in human patients. Although the severity of COVID-19 ranges from asymptomatic to lethal2, most experimental infections provide insights into mild disease3. Here, using K18-hACE2 transgenic mice that were originally developed for SARS studies4, we show that infection with SARS-CoV-2 causes severe disease in the lung and, in some mice, the brain. Evidence of thrombosis and vasculitis was detected in mice with severe pneumonia. Furthermore, we show that infusion of convalescent plasma from a recovered patient with COVID-19 protected against lethal disease. Mice developed anosmia at early time points after infection. Notably, although pre-treatment with convalescent plasma prevented most signs of clinical disease, it did not prevent anosmia. Thus, K18-hACE2 mice provide a useful model for studying the pathological basis of both mild and lethal COVID-19 and for assessing therapeutic interventions.

IL-17A-producing sinonasal MAIT cells in patients with chronic rhinosinusitis with nasal polyps.

BACKGROUND: Diverse immune cells contribute to the pathogenesis of chronic rhinosinusitis (CRS), an inflammatory disease of the nasal cavity and paranasal sinuses. However, whether mucosal-associated invariant T (MAIT) cells are present in human sinonasal tissues remains unclear. Furthermore, the characteristics of sinonasal MAIT cells have not been studied in patients with CRS. OBJECTIVE: We investigated the phenotype, function, and clinical implications of MAIT cells in patients with CRS. METHODS: Peripheral blood and sinonasal tissue were obtained from patients with CRS with (CRSwNP) or without nasal polyps (CRSsNP) and healthy controls. MAIT cells were analyzed by flow cytometry. RESULTS: We found that MAIT cells are present in human sinonasal tissues from healthy controls and patients with CRS. The sinonasal MAIT cell population, but not peripheral blood MAIT cells, from patients with CRSsNP, noneosinophilic CRSwNP (NE-NP), or eosinophilic CRSwNP (E-NP) had a significantly higher frequency of activated cells marked by CD38 expression. In functional analysis, the sinonasal MAIT cell population from NE-NP and E-NP had a significantly higher frequency of IL-17A+ cells but lower frequency of IFN-γ+ or TNF+ cells than control sinonasal tissues. Furthermore, CD38 expression and IL-17A production by sinonasal MAIT cells significantly correlated with disease extent evaluated by the Lund-Mackay computed tomography score in patients with E-NP. CONCLUSIONS: Sinonasal MAIT cells exhibit an activated phenotype and produce higher levels of IL-17A in patients with CRSwNP. These alterations are associated with the extent of disease in patients with E-NP.

Induction of human regulatory innate lymphoid cells from group 2 innate lymphoid cells by retinoic acid.

BACKGROUND: Group 2 innate lymphoid cells (ILC2s) play critical roles in induction and exacerbation of allergic airway inflammation. Thus clarification of the mechanisms that underlie regulation of ILC2 activation has received significant attention. Although innate lymphoid cells are divided into 3 major subsets that mirror helper effector T-cell subsets, counterpart subsets of regulatory T cells have not been well characterized. OBJECTIVE: We sought to determine the factors that induce regulatory innate lymphoid cells (ILCregs). METHODS: IL-10+ ILCregs induced from ILC2s by using retinoic acid (RA) were analyzed with RNA-sequencing and flow cytometry. ILCregs were evaluated in human nasal tissue from healthy subjects and patients with chronic rhinosinusitis with nasal polyps and lung tissue from house dust mite- or saline-treated mice. RESULTS: RA induced IL-10 secretion by human ILC2s but not type 2 cytokines. IL-10+ ILCregs, which were converted from ILC2s by means of RA stimulation, expressed a regulatory T cell-like signature with expression of IL-10, cytotoxic T lymphocyte-associated protein 4, and CD25, with downregulated effector type 2-related markers, such as chemoattractant receptor-homologous molecule on TH2 cells and ST2, and suppressed activation of CD4+ T cells and ILC2s. ILCregs were rarely detected in human nasal tissue from healthy subjects or lung tissue from saline-treated mice, but numbers were increased in nasal tissue from patients with chronic rhinosinusitis with nasal polyps and in lung tissue from house dust mite-treated mice. Enzymes for RA synthesis were upregulated in airway epithelial cells during type 2 inflammation in vivo and by IL-13 in vitro. CONCLUSION: We have identified a unique immune regulatory and anti-inflammatory pathway by which RA converts ILC2s to ILCregs. Interactions between airway epithelial cells and ILC2s play an important roles in the generation of ILCregs.

Chronic rhinosinusitis in elderly patients is associated with an exaggerated neutrophilic proinflammatory response to pathogenic bacteria.

BACKGROUND: Potential effects of aging on chronic rhinosinusitis (CRS) pathophysiology have not been well defined but might have important ramifications given a rapidly aging US and world population. OBJECTIVE: The goal of the current study was to determine whether advanced age is associated with specific inflammatory CRS endotypes or immune signatures. METHODS: Levels of 17 mucus cytokines and inflammatory mediators were measured in 147 patients with CRS. Hierarchical cluster analysis was used to identify and characterize inflammatory CRS endotypes, as well as to determine whether age was associated with specific immune signatures. RESULTS: A CRS endotype with a proinflammatory neutrophilic immune signature was enriched in older patients. In the overall cohort patients 60 years and older had increased mucus levels of IL-1ß, IL-6, IL-8, and TNF-α when compared with their younger counterparts. Increases in levels of proinflammatory cytokines were associated with both tissue neutrophilia and symptomatic bacterial infection/colonization in aged patients. CONCLUSIONS: Aged patients with CRS have a unique inflammatory signature that corresponds to a neutrophilic proinflammatory response. Neutrophil-driven inflammation in aged patients with CRS might be less likely to respond to corticosteroids and might be closely linked to chronic microbial infection or colonization.

Impact of Allergic Rhinitis on Nasal Mucociliary Clearance Time in Children.

BACKGROUND: Mucociliary clearance is one of the most important protective functions of the airway. Previous studies, checking the influence of allergic rhinitis (AR) on mucociliary clearance time (MCT), were made on small patient groups and brought contradictive results. OBJECTIVES: The aim of the study is to confirm whether AR in children influences MCT. METHODS: The examined group consisted of 842 AR children. A total of 96 children with no history of allergy rhinitis served as a comparative group. All patients underwent saccharin and skin prick tests and tests for blood eosinophilia, nasal eosinophilia, vitamin D3 serum concentration, total and specific IgE serum concentration. RESULTS: Nasal MCT was significantly longer in AR patients (mean ± SD: 10.5 ± 5.65 min) compared to controls (mean ± SD: 7.25 ± 4.3 min). Percentage of eosinophils in nasal smears in patients was significantly higher compared to controls and a weak, but significant positive correlation was observed between the percentage and MCT (r > 0.10, p < 0.008). Patients with intermittent and persistent moderate/ severe AR had significantly longer MCT and higher eosinophilia in nasal smears compared both to patients with intermittent and persistent mild RA and controls. No correlation was observed between MCT and: participant's age, total serum IgE, vitamin D3 serum concentration, absolute number or percentage of eosinophils in blood, prick test results or duration of illness. CONCLUSIONS: AR affects the mucociliary clearance in children, and its deterioration is related to more severe rhinitis with higher intensity of local nasal inflammation, reflected in nasal smear eosinophilia.

Focus on the Involvement of the Nose and Paranasal Sinuses in Eosinophilic Granulomatosis with Polyangiitis (Churg-Strauss Syndrome): Nasal Cytology Reveals Infiltration of Eosinophils as a Very Common Feature.

BACKGROUND: Eosinophilic granulomatosis with polyangiitis (EGPA) is a necrotizing vasculitis that predominantly affects small- to medium-sized vessels. It is characterized by a wide spectrum of extrapulmonary symptoms, including sinonasal and paranasal sinus abnormalities. These are the most common features of this disease, constituting diagnostic criteria for EGPA. However, the actual clinical features, cellular mechanisms and impact on patients' quality of life (QoL) are still a matter of study. METHODS: Thirty-nine EGPA patients underwent multidimensional rhinological evaluations, including rhinofibroscopy, nasal cytology, and QoL questionnaires. This was coupled with respiratory and rheumatological assessments. RESULTS: Twenty-eight patients were diagnosed with chronic rhinosinusitis (CRS). Of these, 18 had nasal polyposis (NP). Chronic rhinitis was diagnosed in 10 patients. Of these, 3 had allergic rhinitis (AR) and seven had non-AR (NAR). Overall, only 1 patient (2.6%) was normal. Nasal cytology showed that hypereosinophilia was present in 17/28 patients with CRS, 4/7 patients with NAR and all patients with AR. SNOT-22 and SF-36 showed a severe impact of nasal symptoms on QoL. No differences in asthma control or rheumatological patterns for EGPA were observed among patients with or without NP. CONCLUSIONS: Even when the rheumatological assessment scored EGPA "under control" according to the Birmingham Vasculitis Activity Score and Vasculitis Damage Index, sinonasal diseases and related nasal inflammatory processes were not controlled. Therefore, there is a need for clinical monitoring and targeted treatment to control the inflammatory processes and improve the QoL of EGPA patients.

Efficacy of add-on sublingual immunotherapy for adults with asthma: A meta-analysis and systematic review.

BACKGROUND: Sublingual immunotherapy (SLIT) reduces symptom scores and the use of rescue medication in children with allergic asthma, but the effect of SLIT therapy in adult patients has not been reported. OBJECTIVE: To examine the efficacy and adverse effects of SLIT add-on vs conventional medication in adult patients with mild to moderate asthma. METHODS: We systematically searched the MEDLINE, Embase, Cochrane, and Central databases. Eligible studies included adult patients with allergic asthma who received either SLIT or standard care. Standard mean differences were used as measures of efficacy in a random-effects model. RESULTS: Twenty trials that included 2,288 patients in the SLIT add-on group and 1,268 patients in the traditional therapy group were identified as eligible for final analysis. Compared with traditional therapy, SLIT add-on therapy was associated with significant improvements in lower and upper airway scores, a higher forced expiratory volume in 1 second, and maximal expiratory flow at 25% of forced vital capacity, and improved bronchial reactivity. Drug consumptions were significantly decreased as well. Airway inflammatory parameters, such as nasal eosinophil infiltration, were markedly improved. CONCLUSION: The findings of this study suggested that long-term SLIT add-on therapy is a complementary treatment for adults with asthma in addition to conventional medicine. It not only reduces symptom scores but also improves lung function and airway inflammation.

The use of immunohistochemical methods in the study of morphofunctional features of the human paranasal sinuses: literature review.

OBJECTIVE: Introduction:Chronic inflammatory diseases of the mucous membrane of the nose, paranasal sinuses, and pharynx are the most widespread pathology of the upper airways. The thorough study of the features of the organization of local immune protection of the mucous membrane of the paranasal sinuses is crucial for the deep understanding of the causes of the onset and development of this and other pathologies of the paranasal sinuses, the choice of methods of diagnostics and treatment. Consequently, immunohistochemical studies are of great potential and have become preferable for great number of researchers. The aim: The paper was aimed at the analysis of the publications on the use of immunohistochemical methods in the study of the structural and functional features of the paranasal sinuses. PATIENTS AND METHODS: Materials and methods: The bibliosemantic method has been used during the study. Findings of the current research works on the use of immunohistochemical methods in the study of the paranasal sinuses have been analyzed. RESULTS: Review:The findings of the analysis shows that the use of immunohistochemical methods in the otorhinolaryngology is becoming more and more popular in the study of both morphofunctional features of the paranasal sinuses and in various experimental studies. CONCLUSION: Conclusion: The use of immunohistochemical methods in the study of the paranasal sinuses in both clinical otorhinolaryngology and theoretical morphology is relevant to date and is considered reasonable and perspective.

Nasal interleukin 25 as a novel biomarker for patients with chronic rhinosinusitis with nasal polyps and airway hypersensitiveness: A pilot study.

BACKGROUND: Chronic rhinosinusitis with nasal polyps (CRSwNP) is a chronic inflammatory disease of the upper airway and is tightly linked with airway hyperresponsiveness (AHR) and asthma. However, the surrogate biomarkers for indicating AHR and asthma in patients with CRSwNP remain elusive. OBJECTIVE: To investigate the surrogate biomarkers for indicating AHR and asthma in patients with CRSwNP. METHODS: In this study, sinonasal tissues were collected from 42 patients with CRSwNP (asthma, n = 17; asymptomatic AHR, n = 11; non-AHR, n = 14), 11 patients with chronic rhinosinusitis without nasal polyps (CRSsNP), and 13 controls. The protein and messenger RNA levels of interleukin (IL) 25 and other cytokines in nasal polyp (NP) and control sinonasal tissues were determined by quantitative real-time polymerase chain reaction and multiplex immunoassay, respectively. Multivariate logistic regression and receiver operating characteristic curve analysis were performed to assess the clinical relevance of IL-25. RESULTS: We found that the protein and messenger RNA levels of IL-25 were significantly increased in NP tissues compared with the control sinonasal tissues from patients with CRSwNP, patients with CRSsNP, and controls. Multivariate logistic regression revealed that the nasal IL-25 protein level and nasal and blood eosinophil counts were independent risk factors for AHR in patients with CRSwNP. According to receiver operating characteristic curve analysis, nasal tissue IL-25 had a sensitivity of 91.4% and a specificity of 62.8% (area under the curve, 0.845) at the cutoff level of 5 pg/µL for indicating AHR in this CRSwNP cohort. CONCLUSION: Our findings indicated that IL-25 was significantly increased in NP tissues and may be considered as the molecular indicator for AHR in patients with CRSwNP. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02110654.

Expression of immunoglobulin D is increased in chronic rhinosinusitis.

BACKGROUND: Immunoglobulin (Ig) D is largely localized to the upper airway and reacts with colonizing respiratory pathogens. OBJECTIVE: To determine whether chronic rhinosinusitis (CRS) is associated with increased IgD expression. METHODS: We performed immunofluorescent staining for cytoplasmic IgD, IgA, IgM, and surface plasma cell marker CD138 (syndecan-1) in sinus tissue of patients with CRS with and without nasal polyps (CRSwNP and CRSsNP, respectively) and control subjects without CRS (n = 6 each). Sinonasal mucus antibody levels of patients with CRSwNP or CRSsNP and control subjects were measured by enzyme-linked immunosorbent assay (n = 13, 11, and 9 subjects, respectively). Cells per square millimeter and antibody levels were compared by analysis of variance. Histopathology was performed with sinus tissue from subjects in the 3 groups (n = 6, 8, and 13 subjects respectively). RESULTS: Cells expressing cytoplasmic IgD exceeded those with cytoplasmic IgA and IgM and represented most CD138+ plasma cells in the lamina propria. The frequencies of IgD+ plasma cells were significantly higher in patients with CRSsNP and CRSwNP compared with control subjects (P < .01). Only patients with CRSwNP showed increased frequencies of IgM and IgA plasma cells (P < .01). In contrast to high plasma cell frequencies in tissues, the levels of secreted IgD were lower than those of IgA, IgM, and IgG but were highest in the CRSwNP group compared with the other groups (P < .05). CONCLUSION: IgD plasma cells are prominent in sinus tissues and are increased in CRS. That IgD protein also shows the lowest concentration of antibodies in secretions suggests that its activity might be targeted to the tissue rather than secretions.

Eosinophil production of prostaglandin D2 in patients with aspirin-exacerbated respiratory disease.

BACKGROUND: Aspirin-exacerbated respiratory disease (AERD) differs from aspirin-tolerant disease in part because of eosinophilic tissue infiltration and overexpression of arachidonic acid metabolic pathway components that lead to enhanced secretion of cysteinyl leukotrienes and prostaglandin (PG) D2 observed constitutively and paradoxically in response to aspirin and other COX inhibitors. We have previously demonstrated the capacity of IFN-γ to drive cysteinyl leukotriene expression and response. OBJECTIVE: We investigated eosinophils as a source of PGD2 production in patients with AERD. METHODS: Eosinophils were enriched from tissue and peripheral blood obtained from control subjects, patients with aspirin-tolerant disease, and patients with AERD. mRNA was extracted and evaluated for expression of hematopoietic prostaglandin D synthase (hPGDS). Expression of hPGDS protein was confirmed with Western hybridization and immunofluorescence staining. Cells were stimulated with aspirin, and secretion of PGD2 was quantified. CD34+ progenitor cells were isolated and matured into eosinophils in the presence or absence of IFN-γ and hPGDS mRNA, and PGD2 release was measured. RESULTS: Gene expression analysis revealed that eosinophils from tissue and blood of patients with AERD display increased levels of hPGDS compared with asthmatic and control samples. Western hybridization confirmed the increase in hPGDS mRNA translated to increased protein expression. Immunofluorescence confirmed mast cells and eosinophils from tissue of patients with AERD and asthma demonstrated hPGDS expression, with higher levels in eosinophils from patients with AERD. Incubation of eosinophils from blood and tissue with aspirin stimulated PGD2 release. IFN-γ-matured eosinophil progenitors showed enhanced hPGDS expression and increased levels of PGD2 release at baseline and after aspirin stimulation. CONCLUSIONS: In addition to mast cells, eosinophils represent an important source of PGD2 in patients with AERD and identify a new target for therapeutic intervention.

Taste Receptors Mediate Sinonasal Immunity and Respiratory Disease.

The bitter taste receptor T2R38 has been shown to play a role in the pathogenesis of chronic rhinosinusitis (CRS), where the receptor functions to enhance upper respiratory innate immunity through a triad of beneficial immune responses. Individuals with a functional version of T2R38 are tasters for the bitter compound phenylthiocarbamide (PTC) and exhibit an anti-microbial response in the upper airway to certain invading pathogens, while those individuals with a non-functional version of the receptor are PTC non-tasters and lack this beneficial response. The clinical ramifications are significant, with the non-taster genotype being an independent risk factor for CRS requiring surgery, poor quality-of-life (QOL) improvements post-operatively, and decreased rhinologic QOL in patients with cystic fibrosis. Furthermore, indirect evidence suggests that non-tasters also have a larger burden of biofilm formation. This new data may influence the clinical management of patients with infectious conditions affecting the upper respiratory tract and possibly at other mucosal sites throughout the body.

Nasal nitric oxide in sleep-disordered breathing in children.

BACKGROUND: Inflammation plays a role in the pathogenesis and consequences of sleep-disordered breathing (SDB). The nasal mucosa and paranasal sinuses produce high levels of nitric oxide (NO). In asthma, exhaled NO is a marker of airway inflammation. There is only limited information whether nasal NO (nNO) accompanies also chronic upper airway obstruction, specifically, SDB. The objective of this study was to investigate nNO levels in children with SDB in comparison to healthy non-snoring children. METHODS: Nasal NO was measured in children who underwent overnight polysomnographic studies due to habitual snoring and suspected SDB and in healthy non-snoring controls. RESULTS: One hundred and eleven children participated in the study: 28 with obstructive sleep apnea (OSA), 60 with primary snoring (PS), and 23 controls. Nasal NO levels were significantly higher in children with OSA and PS compared to controls (867.4 ± 371.5, 902.0 ± 330.9, 644.1 ± 166.5 ppb, respectively, p = 0.047). No difference was observed between children with OSA and PS. No correlations were found between nNO levels and any of the PSG variables, nor with age, BMI percentile or tonsils size. CONCLUSIONS: Compared to healthy controls, nNO is increased in children with SDB, but it is not correlated with disease severity. This is probably due to the local mechanical processes and snoring.

Sinus microbiota varies among chronic rhinosinusitis phenotypes and predicts surgical outcome.

BACKGROUND: Chronic rhinosinusitis (CRS) is a prevalent multifactorial disease process in which bacteria are believed to play a role in the propagation of inflammation. Multiple subtypes of CRS have been described based on clinical and pathologic features, but a detailed examination of the sinus microbiota in patients with CRS and its clinical subtypes has yet to be performed. OBJECTIVE: We sought to examine the resident microbiota of CRS subtypes and determine whether bacterial diversity is a predictor of disease outcomes. METHODS: Sinus swabs from patients with CRS and healthy subjects collected during endoscopic sinus surgery were analyzed by means of molecular phylogenetic analysis of 16S rDNA pyrosequences. RESULTS: Fifty-six patients with CRS and 26 control subjects were studied. Biodiversity was similar between the CRS and control groups. Among the CRS subtypes examined, only 2 conditions (presence of purulence and comorbid condition of asthma) were associated with significant alterations in microbial community composition. In 27 patients with CRS who were followed postoperatively, those with better outcomes had more diverse bacterial communities present at the time of surgery, along with higher relative abundances of Actinobacteria. CONCLUSION: Analysis of microbiota in a large cohort reveals that particular CRS phenotypes (asthma and purulence) are characterized by distinct compositions of resident bacterial communities. We found that bacterial diversity and composition are predictors of surgical outcome, promoting the concept of community ecology in patients with CRS.

Sinus and adenoid inflammation in children with chronic rhinosinusitis and asthma.

BACKGROUND: Chronic rhinosinusitis (CRS) and asthma frequently coexist in children and adults. However, the precise pathophysiologic mechanism of this interaction is still poorly understood, especially in children, owing to the lack of direct measurements of mucosal inflammation in the upper airways. OBJECTIVE: To determine the pathophysiologic mechanism by analyzing the expression of a large array of inflammatory cytokines and chemokines in the sinus and adenoid tissues surgically removed from pediatric patients with CRS refractory to medical management. METHODS: Twenty-eight children 2 to 12 years old diagnosed with CRS with or without asthma and 10 controls were included in this prospective, nonrandomized study. Mucosal expression of 40 inflammatory cytokines was measured with a multiplex assay and was normalized to total tissue protein. RESULTS: Compared with children with CRS and without asthma, children with CRS and asthma had significantly higher sinus levels of tumor necrosis factor-α and adenoid levels of epidermal growth factor, eotaxin, fibroblast growth factor-2, growth-related oncogene, and platelet-derived growth factor-AA. CONCLUSION: The inflammatory response in the upper airway mucosa of children with asthma and CRS was similar, but more severe, compared with children with CRS without asthma. This observation is consistent with the hypothesis that asthma in these patients is caused or exacerbated by severe upper airway disease and supports the concept that treating sinus disease is paramount in the management of chronic asthma in children using, for the first time, direct measurements of airway inflammation in children.

The nasal and sinus microbiome in health and disease.

There has been great interest in unraveling the complex inter-relationships between microbes and humans as they relate to human health and disease. This review will focus on recent advances in the appreciation and understanding of these relationships in terms of the upper respiratory tract, specifically the nose and paranasal sinuses.

The effect of smoking on CT score, bacterial colonization and distribution of inflammatory cells in the upper airways of patients with chronic rhinosinusitis.

OBJECTIVE: The study was designed to determine whether smoking affects CT score, bacterial colonization of the upper airways and distribution of inflammatory cells in nasal mucosa in patients with chronic rhinosinusitis. MATERIAL AND METHODS: Sixty-four patients were enrolled in the prospective study. We characterized differences in CT score, rate of revision surgery, differences in bacterial colonization in the middle nasal meatus and distribution of inflammatory cells in nasal tissue in smoking and non-smoking patients with chronic rhinosinusitis with nasal polyps (CRSwNP), chronic rhinosinusitis without nasal polyps (CRSsNP) and control group. RESULTS: Direct tobacco use was associated with significantly more severe form of the disease according to the preoperative CT investigation of paranasal sinuses using Lund-Mackay scoring system in both CRSwNP (p = 0.035) and CRSsNP (p = 0.023) groups. More intense colonization of upper-respiratory tract by the pathogenic bacteria in smokers compared to non-smokers was found. Non-pathogenic bacterial flora was more often present in non-smokers compared to smokers. Plasma cells and lymphocytes were the most numerous cells in nasal tissue in all three groups. In smokers with presence of pathogenic bacteria in middle nasal meatus there was stronger neutrophil (p = 0.002) and macrophage infiltration (p = 0.044) in CRSsNP group. CONCLUSION: Tobacco smoke exposure is related to higher Lund-Mackay score, increased colonization by pathogenic bacteria and lower incidence of commensals in middle nasal meatus, but does not influence cell distribution in nasal mucosa in patients with chronic rhinosinusitis.

Osteoclast-like multinucleated giant cells in sinonasal inflammation of granulomatosis with polyangiitis (Wegener's granulomatosis).

OBJECTIVES: To determine whether generation of osteoclast-like multinucleated giant cells (MNG) is a general feature of granulomatosis with polyangiitis (GPA). METHODS: MNG phenotype of GPA sinus was examined by immunohistochemistry using antibodies against CD68, and cathepsin K. Tartrate resistant acid phosphatase (TRAP) expression was assessed by enzymatic color reaction. Effects of bacterial wall components peptidoglycan (PGN) or lipoteichoic acid (LTA) on TRAP + MNG formation were determined. RESULTS: Tissue infiltrating MNGs in sinus expressed CD68, TRAP, and cathepsin K. They were strikingly less frequent in sinus than in lung lesions (23.1% vs. 70%, p=0.04). PGN and LTA inhibited MNG formation in a dose-dependent manner. CONCLUSIONS: While the generation of osteoclast-like MNGs is an intrinsic feature of GPA, MNGs are rare in sinonasal GPA lesions. Inhibition of MNG formation by bacterial cell wall components may occur preferentially in this sinonasal microenvironment, and contribute to these striking regional pathological differences.

Increased CXCL10 expression in nasal fibroblasts from patients with refractory chronic rhinosinusitis and asthma.

BACKGROUND: Chronic rhinosinusitis (CRS) is characterized by local inflammation of the sinonasal tissues. CRS patients with nasal polyps and asthma often develop acute exacerbation of sinonasal symptoms after upper respiratory tract infections. However, the influence of concomitant asthma on the nasal immune response to viral infection remains unclear. METHODS: Specimens of nasal polyp and mucosal tissues were obtained from 3 groups of CRS patients (n = 14 per group): 1) patients without asthma (CRS group), 2) patients with aspirin-tolerant asthma (ATA group), and 3) patients with aspirin-intolerant asthma (AIA group). Nasal fibroblasts isolated from the specimens were stimulated with poly I:C. CXCL10 expression was analyzed by the quantitative real-time polymerase chain reaction and enzyme-linked immunoadsorbent assay. Biopsy specimens from CRS patients without asthma were subjected to immunohistochemistry for detection of T-bet and GATA-3 expression in CD3+ T cells by double labeling. RESULTS: Nasal fibroblasts from the ATA and AIA groups showed significantly enhanced expression of CXCL10 mRNA and protein after poly I:C stimulation compared with cells from the CRS group and the control group (normal nasal mucosa). In addition to T helper (Th)2 cells, there was more abundant infiltration of Th1 cells into tissues from the AIA and ATA groups. CONCLUSIONS: Our findings suggest that CRS associated with asthma may become intractable through the over-production of CXCL10 in response to viral infection.

[Expression and significance of IgG4 in inflammatory disease of nasal cavity and paranasal sinuses].

OBJECTIVE: To study the prevalence of IgG4-positive plasma cells in inflammatory disease of nasal cavity and paranasal sinuses and its association with IgG4-related sclerosing disease (IgG4-SD). METHODS: The expression of IgG4 and IgG in plasma cells of 103 cases diagnosed as inflammatory disease of nasal cavity and paranasal sinuses with dense lymphoplasmacytic infiltrate was studied by immunohistochemistry (EnVision) and quantitatively analyzed by medical image analysis system. RESULTS: Immunohistochemical study showed marked infiltration by IgG4-positive plasma cells (>50 per high-power field) in 28 cases, moderate infiltration (30 to 50 per high-power field) in 23 cases, mild (10 to 29 per high-power field) in 30 cases and negative (<10 per high-power field) in 22 cases (P < 0.05). Twenty-two cases studied fulfilled the diagnostic criteria of IgG4-SD (>50 IgG4-positive plasma cells per high-power field and IgG4-to-IgG ratio > 40%), including 3 cases of chronic sinusitis (3/20), 3 cases of nasal polyps (3/18), 3 cases of inflammatory pseudotumor (3/17), 4 cases of fungal sinusitis (4/20), 1 case of rhinoscleroma (1/12), 7 cases of Wegener's granulomatosis (7/11) and 1 case of Rosai-Dorfman disease (1/2). CONCLUSION: Inflammatory disease of nasal cavity and paranasal sinuses fulfilling the diagnostic criteria IgG4-SD is not uncommon. Definitive diagnosis of IgG4-SD requires correlation with other clinical and laboratory findings. Some cases of unexplained inflammatory disease of nasal cavity and paranasal sinus may represent a member of the IgG4-SD spectrum. IgG4 carries diagnostic value in differential diagnosis of inflammatory disease occurring in nasal cavity and paranasal sinuses.