Single cell RNA sequencing of human eosinophils from nasal polyps reveals eosinophil heterogeneity in chronic rhinosinusitis tissue.

BACKGROUND: Chronic rhinosinusitis with nasal polyps (CRSwNP) is characterized by type 2 inflammation in the United States, but the actual roles that eosinophils play in CRSwNP remain largely unclear. OBJECTIVE: To reveal the roles and heterogeneity of eosinophils in nasal polyp (NP) tissue, we performed single cell RNA sequencing (scRNA-Seq) analysis of NP tissue. METHODS: Sinonasal tissues (NP and control sinus tissue) and patient matched peripheral blood (PB) samples were obtained from 5 control patients and 5 patients with CRSwNP. Eosinophils were enriched before processing for scRNA-Seq. The gene expression profiles in eosinophils were determined by microwell-based scRNA-Seq technology (BD Rhapsody platform). We predicted the overall function of NP eosinophils by Gene Ontology (geneontology.org) enrichment and pathway analyses and confirmed expression of selected genes by flow cytometry. RESULTS: After filtering out contaminating cells, we detected 5,542 eosinophils from control PB, 3,883 eosinophils from CRSwNP PB, 101 eosinophils from control sinus tissues (not included in further analyses), and 9,727 eosinophils from NPs by scRNA-Seq. We found that 204 genes were downregulated and 354 genes upregulated in NP eosinophils compared to all PB eosinophils (>1.5-fold, Padj < .05). Upregulated genes in NP eosinophils were associated with activation, cytokine-mediated signaling, growth factor activity, NF-κB signaling, and antiapoptotic molecules. NP eosinophils displayed 4 clusters revealing potential heterogeneity of eosinophils in NP tissue. CONCLUSIONS: Elevated eosinophils in NP tissue appear to exist in several subtypes that may play important pathogenic roles in CRSwNP, in part by controlling inflammation and hyperproliferation of other cells.

Evidence that oncostatin M synergizes with IL-4 signaling to induce TSLP expression in chronic rhinosinusitis with nasal polyps.

BACKGROUND: Oncostatin M (OSM) may promote type 2 inflammation in chronic rhinosinusitis with nasal polyps (CRSwNP) by inducing thymic stromal lymphopoietin (TSLP). OBJECTIVE: We sought to study the impact of OSM on TSLP synthesis and release from nasal epithelial cells (NECs). METHODS: OSM receptors, IL-4 receptors (IL-4R), and TSLP were evaluated in mucosal tissue and primary NECs from patients with CRSwNP by quantitative PCR and immunofluorescence. Air-liquid interface-cultured NECs were stimulated with cytokines, including OSM, and quantitative PCR, ELISA, Western blot, and flow cytometry were used to assess the expression of OSM receptors, IL-4R, and TSLP. RESULTS: Increased levels of OSM receptor ß chain (OSMRß), IL-4Rα, and TSLP were observed in nasal polyp tissues and primary epithelial cells from nasal polyps of patients with CRSwNP compared with control tissues or cells from control subjects. The level of expression of OSMRß in tissue was correlated with levels of both IL-4Rα and TSLP. OSM stimulation of NECs increased the expression of OSMRß and IL-4Rα. Stimulation with IL-4 plus OSM augmented the production of TSLP; the response was suppressed by a signal transducer and activator of transcription 6 inhibitor. Stimulation of NECs with IL-4 plus OSM increased the expression of proprotein convertase subtilisin/kexin 3, an enzyme that truncates and activates TSLP. CONCLUSIONS: OSM increases the expression of IL-4Rα and synergizes with IL-4 to induce the synthesis and release of TSLP in NECs. Because the combination of IL-4 and OSM also augmented the expression of proprotein convertase subtilisin/kexin 3, these results suggest that OSM can induce both synthesis and posttranslational processing/activation of TSLP, promoting type 2 inflammation.

Retinoic acid promotes fibrinolysis and may regulate polyp formation.

BACKGROUND: Patients with aspirin-exacerbated respiratory disease (AERD) regularly exhibit severe nasal polyposis. Studies suggest that chronic rhinosinusitis with nasal polyps (CRSwNP) is characterized by excessive fibrin deposition associated with a profound decrease in epithelial tissue plasminogen activator (tPA). Retinoids, including vitamin A and its active metabolite retinoic acid (RA), are necessary for maintaining epithelial function and well-known inducers of tPA in endothelial cells. OBJECTIVES: This study sought to determine whether endogenous retinoids are involved in NP pathophysiology and disease severity in patients with CRSwNP and AERD. METHODS: NP tissue was collected from patients with AERD or CRSwNP, and concentrations of retinoids and fibrinolysis markers were measured using ELISA. Normal human bronchial epithelial cells were stimulated alone or in combination with RA and IL-13 for 24 hours. RESULTS: This study observed lower retinoid levels in nasal polyps of patients with AERD than those with CRSwNP or healthy controls (P < .01). Levels of the fibrin-breakdown product d-dimer were the lowest in AERD polyps (P < .01), which is consistent with lower tPA expression (P < .01). In vitro, all-trans RA upregulated tPA levels in normal human bronchial epithelial cells by 15-fold and reversed the IL-13-induced attenuation of tPA expression in cultured cells (P < .01). CONCLUSIONS: RA, a potent inducer of epithelial tPA in vitro, is reduced in tissue from patients with AERD, a finding that may potentially contribute to decreased levels of tPA and fibrinolysis in AERD. RA can induce tPA in epithelial cells and can reverse IL-13-induced tPA suppression in vitro, suggesting the potential utility of RA in treating patients with CRSwNP and/or AERD.

Efficacy of an oral CRTH2 antagonist (AZD1981) in the treatment of chronic rhinosinusitis with nasal polyps in adults: A randomized controlled clinical trial.

BACKGROUND: Chronic rhinosinusitis with nasal polyps (CRSwNP) is a type 2 inflammatory disease of the upper airways. AZD1981 is a selective antagonist of chemoattractant receptor-homologous molecule expressed on T helper type 2 and other type 2 cells, including innate lymphoid cells type 2, eosinophils, and basophils. OBJECTIVE: To evaluate the efficacy of AZD1981 in reducing nasal polyp size when added to intranasal corticosteroids in adult patients with CRSwNP. METHODS: Eighty-one subjects (18-70 years of age) with CRSwNP were recruited and screened for trial eligibility from allergy and otolaryngology clinics from a single tertiary care site between June 2016 and August 2019. Eligible patients were randomized in a double-blind fashion to receive either AZD1981 (n = 22) or placebo (n = 21) orally three times a day for 12 weeks, added to intranasal corticosteroids. The primary endpoint was a change in nasal polyp score (NPS) at 12 weeks. Secondary endpoints included improvement in sinus computed tomography using Lund Mackay scoring, symptoms using visual analog scale, quality of life using Sino Nasal Outcome Test-22, and the Brief Smell Identification Test. RESULTS: Forty-three patients met the inclusion criteria and were enrolled. At 12 weeks, there was no difference in NPS change in the AZD1981 arm (mean 0, standard error 0.34, n = 15) compared with placebo (mean 0.20, standard error 0.36, n = 17); mean difference -0.20 (95% confidence interval: -1.21, 0.81; p = .69). No significant differences were observed for Lund Mackay score, symptoms, quality of life, or smell test. AZD1981 was well tolerated except for one case of hypersensitivity reaction. CONCLUSION: In patients with CRSwNP, the addition of AZD1981 to intranasal corticosteroids did not change nasal polyp size, radiographic scores, symptoms, or disease-specific quality of life.

Studies on activation and regulation of the coagulation cascade in chronic rhinosinusitis with nasal polyps.

BACKGROUND: Increased activation of the coagulation cascade and diminished fibrinolysis combine to promote fibrin deposition and polyp formation in chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP). More information is needed concerning mechanisms of coagulation in CRSwNP. OBJECTIVE: We investigated the mechanisms as well as the initiation and regulation of coagulation cascade activation in CRS. METHODS: Samples were collected from 135 subjects with CRSwNP, 80 subjects with chronic CRS without nasal polyps (NP), and 65 control subjects. The levels of activated factor X (FXa), prothrombin fragment 1+2 (F1+2), thrombin-antithrombin complex, tissue factor (TF), and TF pathway inhibitor (TFPI) were monitored in CRS by real-time PCR, ELISA, immunohistochemistry, or immunofluorescence. Heteromeric complexes of TF with activated factor VII (FVII) and TF with activated FVII and FXa were assessed by coimmunoprecipitation and Western blotting. RESULTS: Increased levels of FXa, F1+2, and thrombin-antithrombin complex were detected in NP tissue compared to uncinate tissue from CRS and control subjects. Although free TF protein levels were not increased in NP, immunoprecipitation of TF in NP tissue revealed increased complexes of TF with FVII. Local expression of FVII was detected in sinonasal mucosa, and the ratio of TFPI to FXa was lower in NP tissue. CONCLUSION: The coagulation cascade is associated with NP compared to control and uncinate tissue from CRS patients, and TF and FVII are produced locally in sinonasal mucosa in patients. TF and FVII can activate the extrinsic coagulation pathway, suggesting that this pathway may activate fibrin deposition in CRSwNP. Reduced formation of the complex of FXa and TFPI in NP may reduce natural suppression of the extrinsic coagulation pathway in CRSwNP.

Prognostic factors for polyp recurrence in chronic rhinosinusitis with nasal polyps.

BACKGROUND: Chronic rhinosinusitis with nasal polyps is frequently managed with endoscopic sinus surgery (ESS). Prior studies describe individual clinical variables and eosinophil density measures as prognostic for polyp recurrence (PR). However, the relative prognostic significance of these have not been extensively investigated. OBJECTIVES: We sought to evaluate the impact of PR on measures of disease severity post-ESS and quantify the prognostic value of various clinical variables and biomarkers. METHODS: Ninety-four patients with chronic rhinosinusitis with nasal polyps and prospectively biobanked polyp homogenates at the time of ESS were recruited 2 to 5 years post-ESS. Patients were evaluated with patient-reported outcome measures and endoscopic and radiographic scoring pre- and post-ESS. Biomarkers in polyp homogenates were measured with ELISA and Luminex. Relaxed least absolute shrinkage and selection operator regression optimized predictive clinical, biomarker, and combined models. Model performance was assessed using receiver-operating characteristic curve and random forest analysis. RESULTS: PR was found in 39.4% of patients, despite significant improvements in modified Lund-Mackay (MLM) radiographic and 22-item Sinonasal Outcomes Test scores (both P < .0001). PR was significantly associated with worse post-ESS MLM, modified Lund-Kennedy, and 22-item Sinonasal Outcomes Test scores. Relaxed least absolute shrinkage and selection operator identified 2 clinical predictors (area under the curve = 0.79) and 3 biomarkers (area under the curve = 0.78) that were prognostic for PR. When combined, the model incorporating these pre-ESS factors: MLM, asthma, eosinophil cationic protein, anti-double-stranded DNA IgG, and IL-5 improved PR predictive accuracy to area under the curve of 0.89. Random forest analysis identified and validated each of the 5 variables as the strongest predictors of PR. CONCLUSIONS: PR had strong associations with patient-reported outcome measures, endoscopic and radiographic severity. A combined model comprised of eosinophil cationic protein, IL-5, pre-ESS MLM, asthma, and anti-double-stranded DNA IgG could accurately predict PR.

Elevation of activated neutrophils in chronic rhinosinusitis with nasal polyps.

BACKGROUND: Chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP) is well characterized by type 2 (T2) inflammation characterized by eosinophilia in Western countries. However, the presence and roles of neutrophils in T2 CRSwNP are poorly understood. OBJECTIVE: We sought to clarify accumulation and inflammatory roles of neutrophils in CRSwNP in a Western population. METHODS: Sinonasal tissues and nasal lavage fluids were obtained from control patients and patients with CRS, and neutrophil markers were determined by ELISA. The presence of neutrophils in tissue was determined by flow cytometry. The gene expression profiles in neutrophils were determined by RNA sequencing. RESULTS: A neutrophil marker elastase was selectively elevated in nasal polyp (NP) tissue, whereas eosinophilic cationic protein (an eosinophil marker) was elevated in both uncinate and NP tissues of CRSwNP patients. Nasal lavage fluid myeloperoxidase (another neutrophil marker) was also significantly elevated in CRSwNP compared to control patients. Neutrophil markers were more greatly elevated in CRSwNP patients with recurrent disease. Flow cytometric analysis confirmed that neutrophil numbers were significantly elevated in NPs compared to control tissues. RNA sequencing analysis found that 344 genes were >3-fold and significantly elevated in NP neutrophils compared to peripheral blood neutrophils. Gene Ontology analysis suggested that the elevated genes in NP neutrophils were significantly associated with activation. Results suggest that neutrophils are accumulated in T2 NP tissues and that accumulated neutrophils are highly activated and contribute to inflammation in NPs. CONCLUSIONS: Neutrophils may play a heretofore unrecognized meaningful role in the pathogenesis of CRSwNP in Western countries and may be a potentially important therapeutic target in T2 CRSwNP.

Studies of the role of basophils in aspirin-exacerbated respiratory disease pathogenesis.

BACKGROUND: Aspirin-exacerbated respiratory disease (AERD) is characterized by the triad of chronic rhinosinusitis with nasal polyps (CRSwNP), asthma, and intolerance to cyclooxygenase-1 enzyme inhibitors. The underlying mechanisms contributing to AERD pathogenesis are not fully understood, but AERD is characterized by an enhanced type 2 inflammatory phenotype. Basophils are potent type 2 effector cells, but their involvement in AERD pathophysiology remains unclear. OBJECTIVE: We sought to characterize the systemic and local basophil responses in patients with AERD compared with patients with CRSwNP. METHODS: Sinonasal tissues including inferior turbinate and/or nasal polyps (NPs) and peripheral blood were collected from controls, patients with AERD, and patients with CRSwNP. Expression of cell surface (CD45, FcεRI, CD203c), activation (CD63), and intracellular (2D7) markers associated with basophils was characterized using flow cytometry. Clinical data including Lund-Mackay scores and pulmonary function were obtained. RESULTS: The mean number of basophils (CD45+CD203c+FcεRI+CD117-) detected in AERD NPs (147 ± 28 cells/mg tissue) was significantly elevated compared with that detected in CRSwNP NPs (69 ± 20 cells/mg tissue; P = .01). The number of circulating basophils was significantly elevated in patients with AERD (P = .04). Basophils in NPs had significantly higher CD203c and CD63 mean fluorescence intensity compared with blood in both conditions (P < .01). Basophils from AERD NPs had lower expression of the granule content marker 2D7 compared with those from matched blood (P < .01) or NPs of patients with CRSwNP (P = .06), suggesting ongoing degranulation. Basophil 2D7 mean fluorescence intensity significantly correlated with pulmonary function (r = 0.62; P = .02) and inversely correlated with sinonasal inflammation (r = -0.56; P = .004). CONCLUSIONS: Increased basophil numbers and extent of ongoing degranulation in NPs of patients with AERD compared with patients with CRSwNP may contribute to the exaggerated disease pathogenesis and severity unique to AERD.

Increased thrombin-activatable fibrinolysis inhibitor levels in patients with chronic rhinosinusitis with nasal polyps.

BACKGROUND: Chronic rhinosinusitis (CRS) is a heterogeneous chronic inflammatory disease subdivided based on the presence or absence of nasal polyps (NPs). Histologic features of chronic rhinosinusitis with nasal polyps (CRSwNP) include inflammatory cell infiltration and excessive fibrin deposition in NPs. Thrombin-activatable fibrinolysis inhibitor (TAFI) is an enzyme that plays an antifibrinolytic role in the body. The significance of TAFI has been documented in patients with chronic inflammatory diseases, including chronic lung disease; however, it has not been evaluated in the pathogenesis of NPs. OBJECTIVE: The objective of this study was to evaluate the potential role of TAFI in the pathogenesis of NPs. METHODS: Nasal lavage fluid was collected from control subjects and patients with CRS. We measured levels of thrombin/anti-thrombin complex (TATc) and TAFI protein using an ELISA. RESULTS: TATc levels in nasal lavage fluid were significantly increased in patients with CRSwNP and patients with chronic rhinosinusitis without nasal polyps (CRSsNP) compared with control subjects, and TAFI levels in nasal lavage fluid were also significantly increased in patients with CRSwNP compared with those in control subjects and patients with CRSsNP. There was a significant correlation between TATc and TAFI levels in nasal lavage fluid. Interestingly, patients with CRS and asthma showed increased TATc and TAFI levels in nasal lavage fluid compared with those in patients with CRS without asthma, especially patients with CRSwNP. CONCLUSIONS: Increased TATc and TAFI levels in nasal passages of patients with CRSwNP might participate in fibrin deposition in NPs and might play a role in the pathogenesis of CRSwNP and asthma.

A prospective analysis evaluating tissue biopsy location and its clinical relevance in chronic rhinosinusitis with nasal polyps.

BACKGROUND: Chronic rhinosinusitis with nasal polyps (CRSwNP) has a high propensity for recurrence. Studies suggest that eosinophilia influences disease severity and surgical outcomes, but the selection of sinonasal site for measuring eosinophilia has not been examined. The aim of this study was to investigate how region-specific tissue eosinophilia affects radiographic severity, comorbidity prevalence, and polyp recurrence risk following sinus surgery. METHODS: Eosinophil cationic protein (ECP) levels in uncinate tissue (UT) and nasal polyp (NP) homogenates from 116 CRSwNP patients were measured using enzyme-linked immunosorbent assay (ELISA). Clinical history, radiographic severity, and time to polyp recurrence were obtained from electronic health records. The correlations between baseline Lund-Mackay scores and comorbidities were compared between UT and NP ECP levels. Cox regression and Kaplan-Meier analysis were then performed to assess whether UT or NP ECP better predicted recurrence. Censoring occurred at 4 years or at last follow-up if there was no endoscopic diagnosis of recurrent polyps. RESULTS: Lund-Mackay scores were significantly correlated with UT and NP ECP (r = 0.46 and 0.26 respectively, p < 0.05). UT but not NP ECP was significantly higher in patients with asthma (p < 0.01) and aspirin-exacerbated respiratory disease (AERD) (p < 0.05). Polyp recurrence risk was only significantly higher for patients with eosinophilic UT tissue (hazard ratio [HR] = 2.84, p = 0.025). When measured in NP, eosinophilia did not predict recurrence. CONCLUSION: Although ECP in NP was higher than in UT tissue, eosinophilia in UT tissue was a more clinically coherent biomarker of baseline radiographic severity, comorbid asthma and AERD, and prospective polyp recurrence risk than NP eosinophilia.

Evidence for altered levels of IgD in the nasal airway mucosa of patients with chronic rhinosinusitis.

BACKGROUND: IgD is an enigmatic antibody isotype best known when coexpressed with IgM on naive B cells. However, increased soluble IgD (sIgD) levels and increased IgD+IgM- B-cell populations have been described in the human upper respiratory mucosa. OBJECTIVE: We assessed whether levels of sIgD and IgD+ B cell counts are altered in nasal tissue from patients with chronic rhinosinusitis (CRS). We further characterized IgD+ B-cell populations and explored clinical and local inflammatory factors associated with tissue sIgD levels. METHODS: sIgD levels were measured by means of ELISA in nasal tissues, nasal lavage fluid, sera, and supernatants of dissociated nasal tissues. IgD+ cells were identified by using immunofluorescence and flow cytometry. Inflammatory mediator levels in tissues were assessed by using real-time PCR and multiplex immunoassays. Bacterial cultures from the middle meatus were performed. Underlying medical history and medicine use were obtained from medical records. RESULTS: sIgD levels and numbers of IgD+ cells were significantly increased in uncinate tissue (UT) of patients with chronic rhinosinusitis without nasal polyps (CRSsNP) compared with that of control subjects (4-fold, P < .05). IgD+ cells were densely scattered in the periglandular regions of UT from patients with CRSsNP. We also found that IgD+CD19+CD38bright plasmablast numbers were significantly increased in tissues from patients with CRSsNP compared with control tissues (P < .05). Among numerous factors tested, IL-2 levels were increased in UT from patients with CRSsNP and were positively correlated with tissue IgD levels. Additionally, supernatants of IL-2-stimulated dissociated tissue from patients with CRSsNP had significantly increased sIgD levels compared with those in IL-2-stimulated dissociated control tissue ex vivo (P < .05). Tissue from patients with CRS with preoperative antibiotic use or those with pathogenic bacteria showed higher IgD levels compared with tissue from patients without these variables (P < .05). CONCLUSION: sIgD levels and IgD+CD19+CD38bright plasmablast counts were increased in nasal tissue of patients with CRSsNP. IgD levels were associated with increased IL-2 levels and the presence of pathogenic bacteria. These findings suggest that IgD might contribute to enhancement mucosal immunity or inflammation or respond to bacterial infections in patients with CRS, especially CRSsNP.

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

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

Microparticles in nasal lavage fluids in chronic rhinosinusitis: Potential biomarkers for diagnosis of aspirin-exacerbated respiratory disease.

BACKGROUND: Microparticles (MPs) are submicron-sized shed membrane vesicles released from activated or injured cells and are detectable by flow cytometry. MP levels have been used as biomarkers to evaluate cell injury or activation in patients with pathological conditions. OBJECTIVE: We sought to compare MP types and levels in nasal lavage fluids (NLFs) from controls and patients with chronic rhinosinusitis without nasal polyps (CRSsNP), chronic rhinosinusitis with nasal polyps (CRSwNP), and aspirin-exacerbated respiratory disease (AERD). METHODS: We collected NLFs from patients with CRSsNP (n = 33), CRSwNP (n = 45), and AERD (n = 31) and control (n = 24) subjects. Standardized flow cytometry methods were used to characterize the following MP types: endothelial MPs, epithelial MPs (epithelial cell adhesion molecule [EpCAM](+)MPs, E-cadherin(+)MPs), platelet MPs (CD31(+)CD41(+)MPs), eosinophil MPs (EGF-like module-containing mucin-like hormone receptor-like 1[EMR1](+)MPs), mast cell MPs (high-affinity IgE receptor [FcεRI](+)c-kit(+)MPs), and basophil MPs (CD203c(+)c-kit(-)MPs). Basophil activation was evaluated by the mean fluorescence intensity of CD203c on basophil MPs. RESULTS: Activated mast cell MPs (CD137(+) FcεRI(+)c-kit(+)MPs) were significantly increased in NLFs of controls compared with NLFs of patients with CRSsNP (2.3-fold; P < .02), CRSwNP (2.3-fold; P < .03), and AERD (7.4-fold; P < .0001). Platelet MPs (3.5-fold; P < .01) and basophil MPs (2.5-fold; P < .05) were increased only in patients with AERD. Mean fluorescence intensity of CD203c on MPs was increased in patients with CRSwNP (P < .002) and AERD (P < .0001), but not in patients with CRSsNP. EpCAM(+)MPs in patients with CRSwNP were no different from control (P = .91) and lower than those in patients with CRSsNP (P < .02) and AERD (P < .002). CONCLUSIONS: Based on released MPs, mast cells, platelets, and basophils were more highly activated in patients with AERD than in patients with CRS. Epithelial injury was lower in patients with CRSwNP than in patients with CRSsNP and AERD. MP analysis may help identify phenotypes of CRS, and in distinguishing AERD from CRSwNP.

Classical complement pathway activation in the nasal tissue of patients with chronic rhinosinusitis.

BACKGROUND: Complement plays a major role in inflammatory diseases, but its involvement and mechanisms of activation in patients with chronic rhinosinusitis (CRS) are not known. OBJECTIVES: After earlier studies discovering autoantibodies in patients with CRS, we sought to investigate the nature, extent, and location of complement activation in nasal tissue of patients with CRS. Specifically, we were interested in whether antibody-mediated activation through the classical pathway was a major mechanism for complement activation in patients with CRS. METHODS: Nasal tissue was obtained from patients with CRS and control subjects. Tissue homogenates were analyzed for complement activation products (ELISA-C5b-9, C4d, activated C1, and C5a) and major complement-fixing antibodies (Luminex). Tissue sections were stained for C5b-9, C4d, and laminin. Antibodies were purified with protein A/G columns from nasal polyps (NP), matching patient serum, and control serum and assayed for basement membrane binding by means of ELISA. RESULTS: C5b-9 levels were significantly increased in NP tissue compared with uncinate tissue (UT) of patients with chronic rhinosinusitis with nasal polyps (CRSwNP) and those with chronic rhinosinusitis without nasal polyps (CRSsNP; P < .01). Similarly, C4d levels were increased in NPs compared with UT of patients with CRSwNP, patients with CRSsNP, and control subjects (P < .05). Activated C1 levels were also increased in NP tissue compared with UT of patients with CRSsNP and control subjects (P < .05) and correlated with levels of C5a (P < .01), local immunoglobulins (especially IgM, P < .0001), and anti-double-stranded DNA IgG (P < .05). Immunofluorescence showed that C5b-9 and C4d deposition occurred linearly along the epithelial basement membrane. NP tissue extracts had significantly more anti-basement membrane antibodies than sera from patients with CRSwNP and control subjects (P < .0001). CONCLUSION: Levels of C5b-9, C4d, and activated C1 were significantly increased locally in NP tissue. C5b-9 and C4d were almost universally deposited linearly along the basement membrane of NP tissue. Furthermore, activated C1 levels were best correlated with local immunoglobulin and C5a levels. Together, these data suggest that the classical pathway plays a major role in complement activation in patients with CRS.

Neutrophils are a major source of the epithelial barrier disrupting cytokine oncostatin M in patients with mucosal airways disease.

BACKGROUND: We have previously shown that oncostatin M (OSM) levels are increased in nasal polyps (NPs) of patients with chronic rhinosinusitis (CRS), as well as in bronchoalveolar lavage fluid, after segmental allergen challenge in allergic asthmatic patients. We also showed in vitro that physiologic levels of OSM impair barrier function in differentiated airway epithelium. OBJECTIVE: We sought to determine which hematopoietic or resident cell type or types were the source of the OSM expressed in patients with mucosal airways disease. METHODS: Paraffin-embedded NP sections were stained with fluorescence-labeled specific antibodies against OSM, GM-CSF, and hematopoietic cell-specific markers. Live cells were isolated from NPs and matched blood samples for flow cytometric analysis. Neutrophils were isolated from whole blood and cultured with the known OSM inducers GM-CSF and follistatin-like 1, and OSM levels were measured in the supernatants. Bronchial biopsy sections from control subjects, patients with moderate asthma, and patients with severe asthma were stained for OSM and neutrophil elastase. RESULTS: OSM staining was observed in NPs, showed colocalization with neutrophil elastase (n = 10), and did not colocalize with markers for eosinophils, macrophages, T cells, or B cells (n = 3-5). Flow cytometric analysis of NPs (n = 9) showed that 5.1% ± 2% of CD45+ cells were OSM+, and of the OSM+ cells, 56% ± 7% were CD16+Siglec-8-, indicating neutrophil lineage. Only 0.6 ± 0.4% of CD45+ events from matched blood samples (n = 5) were OSM+, suggesting that increased OSM levels in patients with CRS was locally stimulated and produced. A majority of OSM+ neutrophils expressed arginase 1 (72.5% ± 12%), suggesting an N2 phenotype. GM-CSF levels were increased in NPs compared with those in control tissue and were sufficient to induce OSM production (P < .001) in peripheral blood neutrophils in vitro. OSM+ neutrophils were also observed at increased levels in biopsy specimens from patients with severe asthma. Additionally, OSM protein levels were increased in induced sputum from asthmatic patients compared with that from control subjects (P < .05). CONCLUSIONS: Neutrophils are a major source of OSM-producing cells in patients with CRS and severe asthma.

Proton pump inhibitors decrease eotaxin-3/CCL26 expression in patients with chronic rhinosinusitis with nasal polyps: Possible role of the nongastric H,K-ATPase.

BACKGROUND: Chronic rhinosinusitis with nasal polyps (CRSwNP) is often characterized by tissue eosinophilia that is associated with poor prognosis. Recent findings that proton pump inhibitors (PPIs) directly modulate the expression of eotaxin-3, an eosinophil chemoattractant, in patients with eosinophilic diseases suggest therapeutic potential for PPIs in those with CRSwNP. OBJECTIVE: We assessed the effect of type 2 mediators, particularly IL-13 and eotaxin-3, on tissue eosinophilia and disease severity in patients with chronic rhinosinusitis (CRS). Further investigation focused on PPI suppression of eotaxin-3 expression in vivo and in vitro, with exploration of underlying mechanisms. METHODS: Type 2 mediator levels in nasal tissues and secretions were measured by using a multiplex immunoassay. Eotaxin-3 and other chemokines expressed in IL-13-stimulated human sinonasal epithelial cells (HNECs) and BEAS-2B cells with or without PPIs were assessed by using ELISA, Western blotting, real-time PCR, and intracellular pH imaging. RESULTS: Nasal tissues and secretions from patients with CRSwNP had increased IL-13, eotaxin-2, and eotaxin-3 levels, and these were positively correlated with tissue eosinophil cationic protein levels and radiographic scores in patients with CRS (P < .05). IL-13 stimulation of HNECs and BEAS-2B cells dominantly induced eotaxin-3 expression, which was significantly inhibited by PPIs (P < .05). Patients with CRS taking PPIs also showed lower in vivo eotaxin-3 levels compared with those without PPIs (P < .05). Using intracellular pH imaging and altering extracellular K+, we found that IL-13 enhanced H+,K+-exchange, which was blocked by PPIs and the mechanistically unrelated H,K-ATPase inhibitor, SCH-28080. Furthermore, knockdown of ATP12A (gene for the nongastric H,K-ATPase) significantly attenuated IL-13-induced eotaxin-3 expression in HNECs. PPIs also had effects on accelerating IL-13-induced eotaxin-3 mRNA decay. CONCLUSION: Our results demonstrated that PPIs reduce IL-13-induced eotaxin-3 expression by airway epithelial cells. Furthermore, mechanistic studies suggest that the nongastric H,K-ATPase is necessary for IL-13-mediated epithelial responses, and its inhibitors, including PPIs, might be of therapeutic value in patients with CRSwNP by reducing epithelial production of eotaxin-3.

A pilot study of symptom profiles from a polyp vs an eosinophilic-based classification of chronic rhinosinusitis.

BACKGROUND: Chronic rhinosinusitis (CRS) is likely a biologically heterogeneous disease process. Current guidelines propose subclassification using polyp status while others propose using mucosal eosinophilia. We hypothesized that appropriate CRS subclassification would increase homogeneity of baseline symptoms, and identify characteristic symptoms of each subtype. METHODS: A total of 57 CRS patients undergoing surgery prospectively completed a preoperative battery of 73 questions relating to symptoms including the 22-item Sino-Nasal Outcome Test (SNOT-22) and 29-item Patient-Reported Outcomes Measurement Information System (PROMIS-29) general quality of life (QOL) measures. Eosinophilic cationic protein (ECP) levels were determined from ethmoid, uncinate, and polyp tissue homogenates using enzyme-linked immunosorbent assay (ELISA) and normalized to total protein. Patients were classified as eosinophilic (eCRS) or non-eosinophilic (neCRS) using a 95th percentile threshold established from control tissue from 82 patients without CRS. Separate pairwise comparisons were performed on patient-reported symptoms using polyp and eosinophilic status. RESULTS: Of the 57 patients, 28 had CRS with nasal polyps (CRSwNP); 27 of 57 patients had eCRS (CRSwNP, n = 21; CRS without nasal polyps [CRSsNP], n = 6). CRSwNP patients had increased need to blow nose, frequency of nasal congestion, more severe difficulty breathing through nose, more severe nasal discharge, but less cough (p < 0.05). eCRS patients had more bothersome loss of taste/smell, ear pain, sneezing, severe difficulty breathing through nose, and severe nasal congestion compared to neCRS patients (p < 0.05). CONCLUSION: Subclassifying CRS with symptoms alone is difficult with neither polyp status nor eosinophilia giving a distinctive clinical symptom profile. However, certain symptoms may help otolaryngologists identify CRS subtypes, which may help guide future treatments. Further validation and evaluation of prognosis following treatment is required to evaluate appropriate means of subclassifying CRS.