Enhanced release of IgE-dependent early phase mediators from nasal polyp tissue

MZB1-expressing cells are essential for local immunoglobulin production in chronic rhinosinusitis with nasal polyps

BACKGROUND

The expression of MZB1 genes is significantly elevated in patients who have chronic rhinosinusitis with nasal polyp (CRSwNP) disease compared with healthy controls.

OBJECTIVE

To characterize MZB1-positive B cells in CRSwNP and to estimate the contribution of distinct subsets of B cells to the local overproduction of immunoglobulins.

METHODS

Single-cell RNA-sequencing with Cellular Indexing of Transcriptomes and Epitopes by Sequencing technology, Switching Mechanism At the 5' end of RNA Template sequencing, flow cytometry, immunohistochemistry and immunofluorescence staining, Western blot, QuantiGene Plex assay, B-cell ImmunoSpot assay, Luminex assay, and enzyme-linked immunosorbent assay were performed.

RESULTS

Significantly higher mRNA expression of MZB1 and HSP90B1 was found in type 2 CRSwNP compared with controls. In CRSwNP, MZB1 expression correlated with the local production of IgE. MZB1 could be colocalized with plasma and mature B cells, especially marginal zone (MZ) B cells. Single-cell transcriptome and epitope studies revealed prominent populations of B cells in type 2 CRSwNP with unexpectedly high MZB1 gene expression. The MZ B-cell population was significantly increased in CRSwNP compared with healthy controls in both peripheral blood mononuclear cells and nasal tissue single-cell suspensions. When those single cells were cultured overnight, the MZ B-cell numbers were positively correlated with local IgE production but negatively correlated with local IgM production. In vitro, MZB1 stimulation up-regulated the mRNA expression of IgE.

CONCLUSION

MZB1 was primarily expressed by plasma and mature B cells in nasal mucosa. MZB1 expression level was increased in CRSwNP compared with controls. MZB1 contributed to the local IgE production in type 2 CRSwNP.

An update on the role of chronic rhinosinusitis with nasal polyps as a co-morbidity in severe asthma

INTRODUCTION

Chronic rhinosinusitis and asthma are heterogeneous diseases with complex pathogenesis. The presence of chronic rhinosinusitis with nasal polyps has been associated with increased asthma exacerbation frequency and may represent a predictor of future exacerbations in severe asthma.

AREAS COVERED

This review provides the clinician with an overview of the prevalence and clinical impact of the chronic rhinosinusitis with nasal polyps in severe asthma and summarizes recommended therapeutic approaches, including innovative biologic therapies. To select relevant literature for inclusion in this review, we conducted a literature search using the PubMed and ClinicalTrials.gov databases, using terms 'chronic rhinosinusitis with nasal polyps' AND 'asthma' OR 'severe asthma.' The literature review was performed for publication years 2010-2020, restricting the articles to humans and English language publications.

EXPERT OPINION

Biological therapies have opened new perspectives in the treatment of upper and lower airway allergic diseases. Care pathways in severe asthma are almost consolidated, while they still rely on phenotypic rather than endotypic features in chronic rhinosinusitis with nasal polyps. Unveiling the correlation between clinical phenotypes and molecular endotypes will allow better stratification of patients with chronic rhinosinusitis with nasal polyps to identify candidates who benefit most from biological therapy.

A real-world assessment of asthma with chronic rhinosinusitis

BACKGROUND

Chronic rhinosinusitis (CRS) includes 2 main phenotypes: CRS without nasal polyps (CRSsNP) and CRS with nasal polyps (CRSwNP). CRS has been reported to be a comorbidity of asthma.

OBJECTIVE

This study aimed to investigate the role of CRS in outpatients with asthma visited in real-world setting.

METHODS

This cross-sectional study enrolled 499 consecutive outpatients with asthma. Age, sex, body mass index, smoking status, lung function, Asthma Control Test, inflammatory type 2 biomarkers (including fractional exhaled nitric oxide, blood eosinophils, serum total immunoglobulin E, and allergy), treatment step according to the Global Initiative for Asthma, and comorbidities (obstructive sleep apnea syndrome, arterial hypertension, bronchiectasis, diabetes mellitus type 2, and osteoporosis) were evaluated.

RESULTS

A total of 179 (35.87%) patients had CRS, in particular 93 (18.64%) had CRSsNP and 86 (17.23%) had CRSwNP. Type 2 inflammation (defined by at least 1 positive biomarker) was present in 81.44% of patients (fractional exhaled nitric oxide > 30 parts per billion in 46.9%, blood eosinophil count > 300 cell/μL in 39.67%, serum total immunoglobulin E >100 IU/mL in 51.54%, and allergy in 53.71%). By multivariate analysis, type 2 inflammation and blood eosinophils greater than 300 cell/μL were the main predictors (odds ratio [OR] 2.54 and 2.26, respectively) of CRS-asthma association. In particular, CRSwNP comorbidity was predicted by type 2 inflammation (OR 3.4) and blood eosinophils greater than 300 cell/μL (OR 3.0). Smoking had conflicting outcome.

CONCLUSION

This study confirmed that CRS is a frequent asthma comorbidity because it affects more than one-third of outpatients with asthma. CRSwNP is associated with type 2 inflammation and blood eosinophilia. These outcomes underline that CRSwNP asthma phenotype deserves adequate attention for careful management and optimal identification of the best-tailored therapy.

Chronic rhinosinusitis with nasal polyposis: the role of personalized and integrated medicine

Chronic rhinosinusitis with nasal polyposis (CRSwNP) is a frequent disorder. From a clinical and an immunopathological point of view, different phenotypes and endotypes have been identified. The frequent comorbidity with asthma allowed to pave the way to the use of biological agents for the treatment of CRSwNP. Biological agents are targeted to antagonize IgE, interleukin (IL) 4, IL-5, and IL-13 at present. However, a correct and appropriate workup is mandatory, mainly concerning the exact definition of the specific pheno-endotype. The preliminary outcomes are promising, even though there is a need for well-established indications, criteria of responsiveness, duration, and safety. On the other hand, this personalized medicine could be fruitfully integrated with gold-standard medications, such as intranasal corticosteroids. As CRSwNP is a chronic disorder, treatment should be long-lasting, so complementary anti-inflammatory treatments could be opportunely integrated and/or alternated to steroids. (www.actabiomedica.it)

Pathophysiology of chronic rhinosinusitis, pharmaceutical therapy options

Research in immunology has brought great progress in knowledge of inflammatory processes in the last 2 decades, which also has an impact on the upper airways. Our understanding of the pathophysiology of chronic rhinosinusitis developed from a rather mechanistic point of view with a focus on narrow clefts and mucociliary clearance to the appreciation of a complex network of immunological pathways forming the basis of disease. We today differentiate various forms of inflammation, we start to understand complex immune-regulatory networks and the reasons for their failure, and have already developed innovative approaches for therapy for the most severely ill subjects. Due to this new knowledge in inflammation and remodeling processes within mucosal tissue, specifically on the key driving factors, new diagnostic tools and therapeutic approaches for chronic rhinosinusitis have developed; the differentiation of endotypes based on pathophysiological principles will be crucial for the use of innovative therapies, mostly humanized monoclonal antibodies. Several hundred of those antibodies are currently developed for various indications and will impact our specialty as well as pneumology to a great extent.

Aspirin challenge in patients with chronic rhinosinusitis with polyps correlates with local and systemic inflammatory markers

BACKGROUND

Acetylsalicylic acid (ASA; aspirin) is a well-known inducer of pseudoallergic response in patients with chronic rhinosinusitis with polyps (CRSwPs). The mechanism that leads to this response remains unclear. This study was designed to measure and compare the local and systemic inflammatory response to aspirin challenge in patients with CRSwPs who develop either a nasobronchial response (NBR) or a nasal response (NR), and compare it with nonresponders (non-Rs).

METHODS

The three groups underwent nasal wash before ASA challenge, and inflammatory mediators were measured in the nasal wash as well as in serum.

RESULTS

A total of 25 CRSwP patients were enrolled. The NBR patients (n = 13) had a significantly longer mean disease duration and a higher mean serum leukotriene E4 (LTE4) level than the NR (n = 6) and non-R (n = 6) patients (39.2 ± 9.7 months, 21 ± 8.8 months, and 22.8 ± 11.2 months, respectively, and 4221 ± 1205 pg/mL, 1430 ± 605 pg/mL, and 857 ± 461 pg/mL, respectively). The NBR and NR patients had a larger mean number of nasal eosinophils than the non-R group (52.8 ± 28.8 cells/μL, 47 ± 21.3 cells/μL, and 19.3 ± 13.4 cells/μL, respectively). The tryptase, albumin, nasal LTE4, and prostaglandin E2 levels were not significantly different between the three groups in any examined combination.

CONCLUSION

The nasal eosinophil and serum LTE4 levels correlate with aspirin sensitivity.

Transforming growth factor-beta 1 pathways in inflammatory airway diseases

Transforming growth factor-beta 1 (TGF-β1) has been reported being involved in the remodeling and immunosuppression processes of inflammatory airway diseases; understanding the regulation of TGF-β1 is therefore a key to unravel the pathomechanisms of these diseases. This review briefly summarizes the current knowledge on the influencing factors for driving TGF-β1 and its regulatory pathways in inflammatory airway diseases and discusses possible therapeutic approaches to TGF-β1 control. The factors include smoking and oxidative stress, prostaglandins (PGs), leukotrienes (LTs), bradykinin (BK), and microRNAs (miRs). Based on the summary, new innovative treatment strategies may be developed for inflammatory airway diseases with an impaired expression of TGF-β1.

Cannabinoid receptor 1 controls human mucosal-type mast cell degranulation and maturation in situ

BACKGROUND

Because many chronic inflammatory and allergic disorders are intimately linked to excessive mast cell (MC) numbers and activation, it is clinically important to understand the physiologic mechanisms preventing excess MC accumulation/degranulation in normal human tissues.

OBJECTIVE

Because endocannabinoids are increasingly recognized as neuroendocrine regulators of MC biology, we investigated how cannabinoid receptor (CB) 1 signaling affects human mucosal-type mast cells (hMMCs).

METHODS

Using organ-cultured nasal polyps as a surrogate tissue for human bronchial mucosa, we investigated how CB1 stimulation, inhibition, or knockdown affects hMMC biology using quantitative (immuno)histomorphometry and electron microscopy.

RESULTS

Kit(+) hMMCs express functional CB1 in situ. Blockade of CB1 signaling (with the specific CB1 antagonist N-(piperidin-1-yl)-1-(2,4-dichlorophenyl)-5-(4-chlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide [AM251] or CB1 gene knockdown) enhanced hMMC degranulation and increased total numbers without affecting their proliferation in situ. This suggests that inhibiting CB1 signaling induces hMMC maturation from resident progenitor cells within human mucosal stroma. hMMC maturation was induced at least in part through upregulating stem cell factor production. Both the prototypic endocannabinoid anandamide and the CB1-selective agonist arachidonyl-2-chloroethylamide effectively counteracted secretagogue-triggered excessive hMMC degranulation.

CONCLUSIONS

The current serum-free nasal polyp organ culture model allows physiologically and clinically relevant insights into the biology and pharmacologic responses of primary hMMCs in situ. In human airway mucosa hMMC activation and maturation are subject to a potent inhibitory endocannabinoid tone through CB1 stimulation. This invites one to target the endocannabinoid system in human airway mucosa as a novel strategy in the future management of allergic diseases.

Role of imbalance of eicosanoid pathways and staphylococcal superantigens in chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a multifactorial disease of the upper airways with a high prevalence (approximately 11%) in the general population. Different immune and inflammatory mechanisms are involved in its pathogenesis. Alterations in the arachidonic acid pathway (leading to an imbalanced production of eicosanoids) have been linked to the pathophysiology of different diseases especially nasal polyposis, asthma, and aspirin-exacerbated respiratory disease. Furthermore, viral and bacterial infections have been identified as important factors amplifying the pro-inflammatory reactions in these pathologies. This review summarizes the impact of an imbalance in the eicosanoid pathway and the effect of Staphylococcus aureus enterotoxins on the regulation of the pro-inflammatory network in CRS and their translation into disease severity.

Omalizumab is effective in allergic and nonallergic patients with nasal polyps and asthma

BACKGROUND

Adult patients with nasal polyps often have comorbid asthma, adding to the serious effect on the quality of life of these patients. Nasal polyps and asthma might represent a therapeutic challenge; inflammation in both diseases shares many features, such as airway eosinophilia, local IgE formation, and a T(H)2 cytokine profile. Omalizumab is a human anti-IgE mAb with proved efficacy in patients with severe allergic asthma. Omalizumab could be a treatment option for patients with nasal polyps and asthma.

OBJECTIVE

The goal of this study was to investigate the clinical efficacy of omalizumab in patients with nasal polyps and comorbid asthma.

METHODS

A randomized, double-blind, placebo-controlled study of allergic and nonallergic patients with nasal polyps and comorbid asthma (n = 24) was conducted. Subjects received 4 to 8 (subcutaneous) doses of omalizumab (n = 16) or placebo (n = 8). The primary end point was reduction in total nasal endoscopic polyp scores after 16 weeks. Secondary end points included a change in sinus computed tomographic scans, nasal and asthma symptoms, results of validated questionnaires (Short-Form Health Questionnaire, 31-item Rhinosinusitis Outcome Measuring Instrument, and Asthma Quality of Life Questionnaire), and serum/nasal secretion biomarker levels.

RESULTS

There was a significant decrease in total nasal endoscopic polyp scores after 16 weeks in the omalizumab-treated group (-2.67, P = .001), which was confirmed by means of computed tomographic scanning (Lund-Mackay score). Omalizumab had a beneficial effect on airway symptoms (nasal congestion, anterior rhinorrhea, loss of sense of smell, wheezing, and dyspnea) and on quality-of-life scores, irrespective of the presence of allergy.

CONCLUSION

Omalizumab demonstrated clinical efficacy in the treatment of nasal polyps with comorbid asthma, supporting the importance and functionality of local IgE formation in the airways.

Local free light chain expression is increased in chronic rhinosinusitis with nasal polyps

BACKGROUND

Free light chain (FLC) concentrations are demonstrated to be increased in different inflammatory disorders and are proposed to mediate mast cell-dependent immune responses. A role for mast cells is suggested in chronic rhinosinusitis with nasal polyposis (CRSwNP), which is characterized by a local Th2 inflammatory response. However, clear mast cell-activating factors are not always apparent. In this study, the presence of FLCs in CRS patients with or without nasal polyps (CRSw/sNP) was investigated and the effect of different treatments on FLC expression was analyzed.

METHODS

Nasal tissue, nasal secretion, and serum of control patients, patients with CRSwNP, and CRSsNP were analyzed for the presence of kappa and lambda FLC. The expression of FLCs in nasal polyp tissue was investigated using immunohistochemistry. In addition, FLC was measured in serum and nasal secretion of nasal polyp patients treated with methylprednisolone, doxycycline, anti-IL-5, or placebo.

RESULTS

Free light chain concentrations were increased in nasal secretion and mucosal tissue homogenates in patients with chronic rhinosinusitis, and this effect was most prominent in CRSwNP patients. Immunohistochemical analysis confirmed the increased FLC concentrations in nasal polyp tissue. In CRSwNP patients, treatment with methylprednisolone or anti-IL-5 resulted in the reduction in systemic or local FLC concentrations, respectively.

CONCLUSION

The presence of FLC in CRSwNP and CRSsNP suggests a possible role in mediating the local immune reaction in the paranasal cavities. Furthermore, the decrease in local FLCs after treatment with anti-IL-5 presumes that IL-5 creates an environment that favors FLC production.

Glandular mast cells with distinct phenotype are highly elevated in chronic rhinosinusitis with nasal polyps

BACKGROUND

Although chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP) is characterized by T(H)2 inflammation, the role of mast cells is poorly understood.

OBJECTIVE

The objective of this study was to investigate the presence, localization, and phenotype of mast cells in patients with CRS.

METHODS

We collected nasal tissue and nasal lavage fluid from patients with CRS and control subjects. We analyzed mRNA for the mast cell proteases tryptase, chymase, and carboxypeptidase A3 by using real-time PCR and measured mast cell protease proteins by using ELISA, immunohistochemistry, and immunofluorescence.

RESULTS

Tryptase mRNA was significantly increased in nasal polyps (NPs) from patients with CRSwNP (P< .001) compared with uncinate tissue from patients with CRS or control subjects. Tryptase protein was also elevated in NPs and in nasal lavage fluids from patients with CRSwNP. Immnohistochemistry showed increased numbers of mast cells in epithelium and glands but not within the lamina propria in NPs. The mast cells detected in the epithelium in NPs were characterized by the expression of tryptase and carboxypeptidase A3 but not chymase. Mast cells expressing all the 3 proteases were abundant within the glandular epithelium of NPs but were not found in normal glandular structures.

CONCLUSIONS

Herein we demonstrated a unique localization of mast cells within the glandular epithelium of NPs and showed that mast cells in NPs have distinct phenotypes that vary by tissue location. Glandular mast cells and the diverse subsets of mast cells detected may contribute to the pathogenesis of CRSwNP.

A Herbal Composition of Scutellaria baicalensis and Eleutherococcus senticosus Shows Potent Anti-Inflammatory Effects in an Ex Vivo Human Mucosal Tissue Model

Background. Patients seek an effective alternative to pharmacotherapy including herbal treatment options for allergic rhinitis and rhinosinusitis. Material and Methods. Nasal mucosal tissue was obtained from 12 patients, fragmented, preincubated with tissue culture medium, S. baicalensis and/or E. senticosus and/or vitamin C (each compound 0.2 μg/mL and 2 μg/mL) for 1 hour at 37°C/5% CO2, and stimulated with anti-IgE for 30 minutes and 6 hours to imitate the allergic early and late phases. Furthermore, Staphylococcus aureus superantigen B (SEB) stimulation for 6 hours was used to imitate T-cell activation. Results. The combination of S. baicalensis and E. senticosus had a more potent suppressive effect on the release of PGD2, histamine, and IL-5 than S. baicalensis alone. The combination also resulted in a significant inhibition of SEB-induced cytokines comparable or superior to an established topical corticosteroid, fluticasone propionate. Vitamin C increased ciliary beat frequency, but had no anti-inflammatory effects. Discussion. The combination of S. baicalensis and E. senticosus may be able to significantly block allergic early-and late-phase mediators and substantially suppress the release of proinflammatory, and Th1-, Th2-, and Th17-derived cytokines.

Mucosal tissue polyclonal IgE is functional in response to allergen and SEB

BACKGROUND

Staphylococcus aureus may modify airway disease by inducing local formation of polyclonal IgE antibodies (abs), the role of which is unknown.

METHODS

Nasal mucosal tissue and serum was obtained from 12 allergic rhinitis (AR) and 14 nasal polyp (NP) subjects. Skin prick tests were performed, and total and specific IgE abs to inhalant allergens and enterotoxin B were determined in serum and tissue. Tissue fragments were stimulated with anti-IgE, enterotoxin B, or grass and house dust mite allergens in different concentrations for 30 min. RBL SX38 cells were sensitized with NP homogenates containing IgE and stimulated with grass pollen extracts.

RESULTS

In AR patients, degranulation of tissue mast cells upon allergen exposure and presence of specific IgE to inhalant allergens corresponded in almost all cases. Total IgE concentrations in serum and mucosal tissue homogenates highly correlated. In contrast, in NP patients, reactivity of tissue mast cells upon allergen exposure and presence of specific IgE to inhalant allergens or Staphylococcus aureus enterotoxin B corresponded for tissue, but not for serum. Total IgE was significantly higher in tissue compared to serum and failed to show correlation. Tissue IgE to grass pollen was functional to degranulate RBL cells.

CONCLUSION

We here demonstrate that mucosal IgE abs in NP tissue are functional and able to activate mast cells; specific IgE abs in NP tissue can be found independently of their presence in serum. We postulate that superantigen-induced polyclonal IgE in airway disease contributes to chronic inflammation by continuously activating mast cells.

CRTH2 mediates the activation of human Th2 cells in response to PGD(2) released from IgE/anti-IgE treated nasal polyp tissue

BACKGROUND

Mast cells release mediators upon stimulation that contribute to the pathogenesis of chronic airway disease, including the recruitment and activation of Th2 lymphocytes. The objective was to determine the involvement of prostaglandin D(2) (PGD(2)) and its receptors in the chemotaxis of Th2 cells, using nasal polyp tissue.

METHODS

Tissue explants from ten patients with nasal polyposis were incubated with RPMI alone or RPMI containing IgE/anti-IgE for 30 min. Some samples were treated with diclofenac to inhibit the production of PGD(2). Supernatants were assayed for PGD(2) content and for their ability to promote human Th2 cell chemotaxis in the presence and absence of a CRTH2 antagonist. Transcript levels of D protanoid receptor type 1 (DP(1)), chemoattractant receptor-homologous receptor expressed on Th2 cells (CRTH2) and PGD(2) synthase were analysed by real time PCR.

RESULTS

Increased release of PGD(2) by nasal polyp tissue treated with IgE/anti-IgE was significantly inhibited by preincubation of the tissue with diclofenac. Transcript levels of PGD(2) synthase, DP(1) and CRTH2 receptors increased after stimulation with IgE/anti-IgE. Supernatants from IgE/anti-IgE-stimulated nasal polyp tissue caused significantly increased chemotaxis of Th2 cells. The levels of PGD(2) produced and the degree of Th2 cell chemotaxis were highly correlated. Diclofenac inhibited the production of Th2 cell chemotactic activity, and the chemotactic effect of the supernatant on Th2 cells was inhibited by the CRTH2 antagonist ramatroban.

CONCLUSION

These data suggest that in immunologically activated nasal polyp tissue, PGD(2) produced by mast cells promotes the migration of Th2 cells through a CRTH2 dependent mechanism.