Eotaxin mRNA and protein expression in chronic sinusitis and allergen-induced nasal responses in seasonal allergic rhinitis

Mouse Model of Nitrogen Mustard Ocular Surface Injury Characterization and Sphingolipid Signaling

Vesicating chemicals like sulfur mustard (SM) or nitrogen mustard (NM) can cause devastating damage to the eyes, skin, and lungs. Eyes, being the most sensitive, have complicated pathologies that can manifest immediately after exposure (acute) and last for years (chronic). No FDA-approved drug is available to be used as medical counter measures (MCMs) against such injuries. Understanding the pathological mechanisms in acute and chronic response of the eye is essential for developing effective MCMs. Here, we report the clinical and histopathological characterization of a mouse model of NM-induced ocular surface injury (entire surface) developed by treating the eye with 2% (w/v) NM solution for 5 min. Unlike the existing models of specific injury, our model showed severe ocular inflammation, including the eyelids, structural deformity of the corneal epithelium and stroma, and diminished visual and retinal functions. We also observed alterations of the inflammatory markers and their expression at different phases of the injury, along with an activation of acidic sphingomyelinase (aSMase), causing an increase in bioactive sphingolipid ceramide and a reduction in sphingomyelin levels. This novel ocular surface mouse model recapitulated the injuries reported in human, rabbit, and murine SM or NM injury models. NM exposure of the entire ocular surface in mice, which is similar to accidental or deliberate exposure in humans, showed severe ocular inflammation and caused irreversible alterations to the corneal structure and significant vision loss. It also showed an intricate interplay between inflammatory markers over the injury period and alteration in sphingolipid homeostasis in the early acute phase.

The interplay of inflammation and remodeling in the pathogenesis of chronic rhinosinusitis: current understanding and future directions

Chronic rhinosinusitis (CRS), a common clinical condition characterized by persistent mucosal inflammation and tissue remodeling, has a complex pathogenesis that is intricately linked to innate and adaptive immunity. A number of studies have demonstrated that a variety of immune cells and cytokines that play a vital role in mediating inflammation in CRS are also involved in remodeling of the nasal mucosa and the cells as well as different cytokines involved in remodeling in CRS are also able to exert some influence on inflammation, even though the exact relationship between inflammation and remodeling in CRS has not yet been fully elucidated. In this review, the potential role of immune cells and cytokines in regulating inflammation and remodeling of CRS mucosa has been described, starting with the immune cells and cytokines that act together in inflammation and remodeling. The goal is to aid researchers in understanding intimate connection between inflammation and remodeling of CRS and to offer novel ideas for future research.

Febuxostat Alleviates Allergic Rhinitis by Inhibiting Inflammation and Monocyte Adhesion in Human Nasal Epithelial Cells via Regulating KLF6

Introduction

Febuxostat is a novel inhibitor of xanthine oxidase that suppresses cell adhesion molecules-mediated (CAMs) inflammation by activating KLF6. In this study, we explored the therapeutic function and potential mechanisms of febuxostat against allergic rhinitis (AR).

Methods

We investigated the role of febuxostat through in vitro cell and in vivo animal experiments. Human nasal epithelial cells (hNECs) were cultured with histamine as an in vitro model. To establish the AR animal model, rats were exposed to ovalbumin. Rats were randomly grouped into control, model, 7.5 mg/kg febuxostat, and 15 mg/kg febuxostat groups.

Results

In the in vitro study, we found significantly increased release of lactate dehydrogenase, elevated production of inflammatory factors and chemokines, and upregulated CAMs in histamine-treated hNECs. However, these results were significantly reversed for the 10 and 20 μM febuxostat treatments. The enhanced adhesion between hNECs and monocytes induced by histamine was dramatically repressed by febuxostat. In the vivo experiments, we observed that febuxostat ameliorated the increased sneezing times, the number of nose scratching episodes, and elevated HE pathological scores as well as alleviated the inflammation in nasal mucous tissues of AR mice. We found that KLF6, which was downregulated in histamine-treated hNECs, was significantly upregulated by febuxostat. The inhibitory effects of febuxostat on the expression levels of CAMs and adhesion between histamine-treated hNECs and monocytes were significantly abolished by the knockdown of KLF6.

Conclusion

Febuxostat alleviates AR by inhibiting inflammation and monocyte adhesion in human nasal epithelial cells through the regulation of KLF6.

Mechanism of Lower Airway Hyperresponsiveness Induced by Allergic Rhinitis

Allergic rhinitis is a global illness that puzzles many researchers. Most patients with allergic rhinitis also have lower airway hyperresponsiveness, and an allergic rhinitis attack can increase lower airway hyperresponsiveness. However, the mechanism of the effect of allergic rhinitis on the lower airways is still unclear. In this paper, the effects of allergic rhinitis on the lower airways are studied in terms of epidemiology, anatomy, pathophysiology, nasal function loss, inflammation drainage, nasobronchial reflex, and whole-body circulatory flow to determine the mechanism involved and provide ideas for future diagnosis, treatment, and experiments.

Increased Thrombin-Activatable Fibrinolysis Inhibitor in Response to Sublingual Immunotherapy for Allergic Rhinitis

OBJECTIVES/HYPOTHESIS

The objective of this study was to determine the role of thrombin-activatable fibrinolysis inhibitor (TAFI) as a candidate biomarker for therapeutic efficacy of sublingual immunotherapy (SLIT) and to identify the role of TAFI in the pathogenesis of allergic rhinitis (AR).

STUDY DESIGN

Retrospective cohort study and laboratory study.

METHODS

Serum was collected from patients with allergies to Japanese cedar pollen before, during, and after treatment with SLIT. We measured the levels of immunoreactive TAFI, C3a, and C5a in serum by enzyme-linked immunosorbent assay (ELISA) and assessed their relative impact on a combined symptom-medication score. We also examined the impact of TAFI on mast cells and fibroblasts in experiments performed in vitro.

RESULTS

Serum levels of TAFI increased significantly in response to SLIT. By contrast, serum C3a levels decreased significantly over time; we observed a significant negative correlation between serum levels of TAFI versus C3a and symptom-medication score. Mast cell degranulation was inhibited in response to TAFI, as it was the expression of both CCL11 and CCL5 in cultured fibroblasts.

CONCLUSIONS

High serum levels of TAFI may be induced by SLIT. TAFI may play a critical protective role in pathogenesis of AR by inactivating C3a and by inhibiting mast cell degranulation and chemokines expression in fibroblasts.

LEVEL OF EVIDENCE

4 Laryngoscope, 2021.

The Role of Allergic Rhinitis in Chronic Rhinosinusitis

This literature review collates and summarizes recent literature to explore the relationship between chronic rhinosinusitis (CRS) and allergy. The relationship between CRS and allergy is not fully understood. However, current evidence suggests a relationship between allergy and specific endotypes of CRS with nasal polyposis, including allergic fungal rhinosinusitis and central compartment atopic disease. Specific endotypes of CRS with nasal polyps seem to have an association with allergy. More evidence is necessary to better characterize this relationship. Level of evidence: 5.

Expression of COX-1, COX-2, 5-LOX and CysLT 2 in nasal polyps and bronchial tissue of patients with aspirin exacerbated airway disease

Background

Aspirin exacerbated respiratory disease (AERD) is a disease of the upper and lower airways. It is characterized by severe asthma, chronic sinusitis with nasal polyps (CRSwNP) and intolerance towards nonsteroidal analgesics (NSAR). Arachidonic acid (AA) metabolites play an important role in the pathogenesis of AERD. It is still unknown, whether metabolism of AA is comparable between the upper and lower airways as well as between patients with and without NSAR intolerance.

Objective

We sought to analyze differences in the expression of cyclooxygenases type 1 and 2 (COX-1, COX-2), arachidonate 5-lipoxygenase (5-LOX) and cysteinyl leukotriene receptor type 2 ( CysLT 2 ) in nasal polyps and the bronchial mucosa of patients with aspirin intolerant asthma (AIA, n = 23 ) as compared to patients with aspirin tolerant asthma (ATA, n = 17 ) and a control group with nasal polyps, but without asthma (NPwA, n = 15 ).

Methods

Tissue biopsies from nasal polyps and bronchial mucosa were obtained during surgical treatment of nasal polyps by endonasal functional endoscopic sinus surgery (FESS) under general anesthesia from intubated patients. Immunohistochemistry was used to analyze the expression of COX-1, COX-2, 5-LOX and CysLT 2 in nasal and bronchial mucosa. Categorization into the different patient groups was performed according to the patient history, clinical and laboratory data, pulmonary function and provocation tests, as well as allergy testing.

Results

We observed a stronger expression of 5-LOX and CysLT 2 in submucosal glands of nasal and bronchial tissue compared to epithelial expression. The expression of COX-1 and COX-2 was stronger in epithelia compared to submucosal glands. There was a similar expression of the enzymes and CysLT 2 between upper and lower airways in all patient groups. We did not detect any significant differences between the patient groups.

Conclusions

The AA-metabolizing enzymes and the CysLT 2 were expressed in a very similar way in different microscopic structures in samples of the upper and lower airways of individual patients. We did not detect differences between the patient groups indicating the pathogenetic role of AA metabolism in these disorders is independent of the presence of NSAR-intolerance.

Chronic Rhinosinusitis: Does Allergy Play a Role?

A few chronic rhinosinusitis (CRS) variants have demonstrated a strong association with environmental allergy, including allergic fungal rhinosinusitis (AFRS) and central compartment atopic disease (CCAD). However, the overall relationship between CRS and allergy remains poorly defined. The goal of this review is to evaluate the relationship between CRS and allergy with a focus on specific CRS variants.

Association between plasma CCL11 (eotaxin-1) and cognitive status in older adults: Differences between rural and urban dwellers

The chemokine CCL11 has been implicated in age-related cognitive deterioration in mice, yet evidence on the relationship between CCL11 and cognitive function in humans is limited. This study explored associations between CCL11 and cognition in rural and urban community-dwelling older adults. Participants were 515 urban dwellers from the 3C-Bordeaux cohort and 318 rural dwellers from the AMI cohort. Plasma CCL11 was measured using an enzyme-linked immunoassay. Mini Mental State Examination (MMSE) test scores were used as the main measure of cognitive performance. Multivariate regression analysis was used to evaluate the cross-sectional association between CCL11 and cognitive performance. CCL11 was significantly higher in rural dwellers compared to city dwellers (median [IQR]: 145 [115-201] pg/mL vs. 103 [85-129] pg/mL; p < 0.001). After adjustment for confounders, CCL11 was found to be negatively associated with cognitive performance in rural dwellers but not in city dwellers. These results suggest that CCL11 may be an independent determinant of cognitive function in older rural dwellers and that the residential environment modifies this association.

The Role of RANTES in Nasal Polyposis

Background

Characteristic infiltrates of eosinophils are a hallmark of nasal polyps (NPs). Several studies suggest that members of the CC chemokine family may be involved in this process. RANTES (regulated on activation, normal t-cell-expressed and secreted) is a member of the CC chemokine family with chemotactic activity on mainly eosinophils and T lymphocytes. Thus, RANTES is an interesting target for the recruitment of eosinophils and T lymphocytes into the nose. The degree of the tissue eosinophilia has been reported to correlate with the severeness of the symptomatology of the disease and the extension on the lower respiratory tract, as well as with the probability of the recurrence of NPs. Therefore, we hypothesized that high numbers of eosinophils correlate with high levels of RANTES and that associated atopic diseases modify this correlation.

Methods

Total RNA was extracted from NP homogenates, reverse transcribed and RANTES mRNA expression analyzed using semiquantitative reverse transcription polymerase chain reaction and Northern blot analysis. Histological studies divided NPs in an eosinophilic and low eosinophilic group. Additionally, RANTES protein concentration was measured in homogenates by a RANTES-specific enzyme-linked immunosorbent assay.

Results

This study has clearly shown that RANTES is expressed and secreted in NPs. The group with a high tissue eosinophilia had a significant higher RANTES gene expression and protein production than NPs without tissue eosinophilia. The isolated coincidence of acetylsalicyl acid intolerance with chronic hyperplastic sinusitis/NP additionally increased significantly the RANTES amounts in NPs.

Conclusion

Increased RANTES leads to increased tissue eosinophilia. Associated acetylsalicylic acid intolerance seems to enhance the amount of RANTES in NPs and might explain in part the more severe clinical course in those patients. Thus, RANTES appears to play an important role in mobilization of eosinophils into the local inflamed tissue.

Study of Eosinophil Activation in Nasal Mucosa in Patients with Perennial Nasal Allergy: Effects of CO2 Laser Surgery

Carbon dioxide (CO2) laser surgery has been shown to be clinically effective in the treatment of nasal allergy. To investigate the mechanisms of eosinophil infiltration and activation underlying the therapeutic effects of CO2 laser surgery, we examined changes in the cytological profile of nasal mucosa after surgery. Twenty-two patients with perennial nasal allergy against house-dust mites underwent two or three rounds of laser surgery at 1-month intervals on an outpatient basis. The following parameters were evaluated at each visit: (i) improvement of clinical symptoms (nasal obstruction, rhinorrhea, and sneezing), (ii) percentage of infiltrating eosinophils in nasal mucosa, and (iii) the degree of EG2+ cells and intracellular adhesion molecule 1 (ICAM-1) expression by immunocyto-chemistry. All clinical symptoms significantly decreased after surgery. Significant reductions in eosinophil infiltration (p < 0.01) and the percentage of EG2+ cells (p < .005) were observed also. However, the degree of ICAM-1 expression in epithelial cells was not changed. These results suggest that CO2 laser surgery partially reduced the allergic reactions, leading to improvement of clinical symptoms.

Eosinophils and Mast Cells in Aspirin-Exacerbated Respiratory Disease

Aspirin-exacerbated respiratory disease (AERD) involves overexpression of proinflammatory mediators, including 5-lipoxygenase and leukotriene C₄ synthase (LTC₄S), resulting in constitutive overproduction of cysteinyl leukotrienes. Mast cells and eosinophils have roles in mediating many of the observed effects. Increased levels of both interleukin-4 (IL-4) and interferon (IFN)-γ are present in the tissue of patients with AERD. Previous studies showed that IL-4 is primarily responsible for the upregulation of LTC₄S by mast cells. Our studies show that IFN-γ, but not IL-4, drives this process in eosinophils. This article examines the overall role that eosinophils and mast cells contribute to the pathophysiology of AERD.

Natural Killer Cell Deficits Aggravate Allergic Rhinosinusitis in a Murine Model

OBJECTIVE

Defective innate immune functions can contribute to chronic rhinosinusitis (RS). Recently, it has been reported that chronic RS patients show impaired function of natural killer (NK) cells. We investigated the role of NK cells in eosinophilic inflammation in an allergic RS mouse model.

METHODS

Mice sensitized to ovalbumin (OVA) by intraperitoneal injection received nasal challenges with OVA for 5 weeks. NK cell depletion was achieved by intraperitoneal injections of anti-asialo ganglio-N-tetraosylceramide (ASGM1) antibodies 10 days before OVA sensitization and every 5 days thereafter until sacrifice. Sinonasal complex samples were evaluated histologically, and IL-4, IL-5, IL-13, IFN-γ, MIP-2, and eotaxin levels were measured in the nasal lavage fluid. Differential white blood cell counts were also obtained.

RESULTS

Allergic RS mice showed significantly more eosinophilic inflammation in the sinonasal mucosa, elevated levels of IL-4, IL-5, IL-13, and eotaxin in the nasal lavage fluid, and peripheral blood eosinophilia compared to control mice. The depletion of NK cells by anti-ASGM1 treatment induced more prominent eosinophilic inflammation and increased secretion of IL-5 and peripheral blood eosinophilia in allergic RS mice.

CONCLUSION

The depletion of NK cells aggravates allergen-induced sinonasal eosinophilic inflammation, suggesting that impaired NK cell activity may be an exacerbating factor in eosinophilic chronic RS.

Drivers of chronic rhinosinusitis: Inflammation versus infection

Studies of the underlying cause or causes of chronic rhinosinusitis (CRS) over the past 20 or more years have expanded from a focus on systemic immune and allergic mechanisms to an intense search for the underlying drivers of mucosal inflammation. These drivers involve mucosal inflammatory pathways that become activated by allergens, microbial stimuli, or poorly understood exogenous or endogenous stimuli. The holy grail in the study of CRS is to identify specific drivers of mucosal inflammation and translate these into more effective treatment for CRS. Certain deficiencies in local innate immunity have been described in patients with CRS that predispose to increased sinus mucosal bacterial colonization/infection, including deficient local production of antimicrobial lactoferrin and deficient functioning of the bitter taste receptor TAS2R38. Conversely, certain innate factors, namely IL-25, IL-33, and thymic stromal lymphopoietin (TSLP), are elaborated by sinus epithelial cells in response to microbial stimulation or airway injury and promote local TH2 inflammation. The precise physiologic role of these factors in innate or adaptive immunity is unclear, although IL-33 might function as an alarmin triggered by damage-associated molecular patterns. The cytokines IL-25 and TSLP, similarly promote proinflammatory tissue responses. Another feature of epithelial dysregulation in patients with CRS is overproduction of eosinophil-promoting C-C chemokines by sinus epithelium, perhaps driven in part through innate stimuli, as well as TH2 cytokines, such as IL-13. Strategies to reduce the microbial stimulation of maladaptive TH2 inflammation or to suppress the local elaboration of TH2-promoting epithelial factors, such as IL-33, have potential therapeutic benefit in patients with CRS, although the extent to which this is realized in patient care remains limited at present. This rostrum will summarize my views on the major microbial drivers of mucosal inflammation and dysregulation of innate TH2-promoting factors in patients with CRS based on recent experimental data.

Antileukotrienes in upper airway inflammatory diseases

Leukotrienes (LTs) are a family of inflammatory mediators including LTA4, LTB4, LTC4, LTD4, and LTE4. By competitive binding to the cysteinyl LT1 (CysLT1) receptor, LT receptor antagonist drugs, such as montelukast, zafirlukast, and pranlukast, block the effects of CysLTs, improving the symptoms of some chronic respiratory diseases, particularly bronchial asthma and allergic rhinitis. We reviewed the efficacy of antileukotrienes in upper airway inflammatory diseases. An update on the use of antileukotrienes in upper airway diseases in children and adults is presented with a detailed literature survey. Data on LTs, antileukotrienes, and antileukotrienes in chronic rhinosinusitis and nasal polyps, asthma, and allergic rhinitis are presented. Antileukotriene drugs are classified into two groups: CysLT receptor antagonists (zafirlukast, pranlukast, and montelukast) and LT synthesis inhibitors (5-lipoxygenase inhibitors such as zileuton, ZD2138, Bay X 1005, and MK-0591). CysLTs have important proinflammatory and profibrotic effects that contribute to the extensive hyperplastic rhinosinusitis and nasal polyposis (NP) that characterise these disorders. Patients who receive zafirlukast or zileuton tend to show objective improvements in, or at least stabilisation of, NP. Montelukast treatment may lead to clinical subjective improvement in NP. Montelukast treatment after sinus surgery can lead to a significant reduction in eosinophilic cationic protein levels in serum, with a beneficial effect on nasal and pulmonary symptoms and less impact in NP. Combined inhaled corticosteroids and long-acting β-agonists treatments are most effective for preventing exacerbations among paediatric asthma patients. Treatments with medium- or high-dose inhaled corticosteroids, combined inhaled corticosteroids and LT receptor antagonists, and low-dose inhaled corticosteroids have been reported to be equally effective. Antileukotrienes have also been reported to be effective for allergic rhinitis.

Differences in urinary leukotriene E4 levels and distribution of eosinophils between chronic rhinosinusitis patients with aspirin-intolerant and -tolerant asthma

OBJECTIVE

Urinary leukotriene E4 (U-LTE4) concentrations are significantly elevated in patients with aspirin-intolerant asthma (AIA). However, the relationship between the clinicopathogenetic features of eosinophilic rhinosinusitis and U-LTE4 concentration remains unknown. Here we examined the relationship between U-LTE4 level and eosinophil in chronic rhinosinusitis.

METHODS

We measured the U-LTE4 concentrations and eosinophil counts in ethmoidal and maxillary sinuses and peripheral blood in 30 asthmatic patients (including 15 AIA patients).

RESULTS

Eosinophil counts in ethmoidal sinuses and peripheral blood were markedly higher in asthmatic patients than in controls. Although there were no significant differences between eosinophil counts in maxillary and ethmoidal sinuses for ATA group, eosinophil counts were higher in ethmoidal sinus compared to that in maxillary sinus in the AIA group (P<.05). Eosinophil counts were higher in the maxillary than in ethmoidal sinuses for control patients (P<.05). Despite low correlation between eosinophil counts in peripheral blood and eosinophil counts in maxillary sinus (rs=0.4323, P<.001), moderate correlation was observed between eosinophil counts in peripheral blood and eosinophil counts in ethmoidal sinus (rs=0.5249, P<.0001). Basal U-LTE4 concentrations were higher in AIA patients than in those with aspirin-tolerant asthma. Despite low correlation between eosinophil counts and U-LTE4 concentration in maxillary sinus (rs=0.3849, P<.01), moderate correlation was observed between eosinophil counts and U-LTE4 concentrations in ethmoidal sinus (rs=0.4736, P<.001).

CONCLUSION

We describe the differences in U-LTE4 and other parameters in AIA compared to ATA, and correlation among parameters. We demonstrate that eosinophil-dominant inflammation starts in ethmoidal sinus clinicopathogenetically in CRS with asthma. U-LTE4 concentration was not exclusively associated with eosinophil counts in ethmoidal sinus. Eosinophils in ethmoidal sinus may be a major production site for CysLTs, particularly in AIA. CRS with AIA is assumed to be characterized by leukotriene-eosinophil cross-interaction in ethmoidal sinus.

Factors driving the aspirin exacerbated respiratory disease phenotype

BACKGROUND

Aspirin-exacerbated respiratory disease (AERD) is explained in part by overexpression of 5-lipoxygenase and leukotriene C4 synthase (LTC4S), resulting in constitutive overproduction of cysteinyl leukotrienes (CysLTs) and driving the surge in CysLT production that occurs with aspirin ingestion. Similarly, AERD is characterized by the overexpression of CysLT receptors. Increased levels of both interleukin (IL)-4 and interferon (IFN)-γ are present in the tissue of AERD subjects. Previous studies demonstrated that IL-4 is primarily responsible for the up-regulation of LTC4S by mast cells.

METHODS

Literature review.

RESULTS

Our previous studies demonstrated that IFN-γ, but not IL-4, drives this process in eosinophils. These published studies also extend to both IL-4 and IFN-γ the ability to up-regulate CysLT receptors. Prostaglandin E2 (PGE2) acts to prevent CysLT secretion by inhibiting mast cell and eosinophil activation. PGE2 concentrations are reduced in AERD, and our published studies confirm that this reflects diminished expression of cyclooxygenase (COX)-2. A process again that is driven by IL-4. Thus, IL-4 and IFN-γ together play an important pathogenic role in generating the phenotype of AERD. Finally, induction of LTC4S and CysLT1 receptors by IL-4 reflects in part the IL-4-mediated activation of signal transducer and activator of transcription 6 (STAT6). Our previous studies demonstrated that aspirin blocks trafficking of STAT6 into the nucleus and thereby prevents IL-4-mediated induction of these transcripts, thereby suggesting a modality by which aspirin desensitization could provide therapeutic benefit for AERD patients.

CONCLUSION

This review will examine the evidence supporting this model.

Profibrotic transforming growth factor beta 1 and activin A are increased in nasal polyp tissue and induced in nasal polyp epithelium by cigarette smoke and Toll-like receptor 3 ligation

BACKGROUND

The mechanism of airway remodeling in chronic rhinosinusitis with nasal polyposis (CRSwNP) remains unknown. We wished to determine whether profibrotic transforming growth factor beta 1 (TGF-β1) and activin A and their downstream signaling proteins are increased in CRSwNP and if they are regulated in epithelial cells by noxious or inflammatory stimuli.

METHODS

Frozen tissue from CRSwNP patients, healthy control (HC) middle turbinates, and sinus tissue from CRS without NP (CRSsNP) patients were immunostained for TGF-β1, activin A, and downstream signaling proteins. Primary nasal epithelial cells (PNECs) from HCs and CRSwNP patients were cultured in media, cigarette smoke extract (CSE), or double-stranded RNA (dsRNA) (a ligand for Toll-like receptor-3) and examined for inflammatory and profibrotic genes using real-time polymerase chain reaction (PCR).

RESULTS

CRSwNP patients showed increased TGF-β1 and activin A in the stroma, increased TGF-β1 signaling (phosphorylated Smad2/3) in the stroma and epithelium, and increased Smad3-dependent Snail1 in the stroma. Immunostaining for TGF-β1, pSmad2/3, and Snail1 in CRSwNP patients was highly correlated. Immunostaining for pSmad2/3 and Snail1 was similar in CRSwNP and CRSsNP patients. Compared to HCs, PNECs from CRSwNP patients were more responsive to CSE and dsRNA in terms of TGF-β1 and activin A and more strongly induced by dsRNA in terms of chemokines.

CONCLUSION

Increased TGF-β1 and activin A and increased downstream TGF-β1 signaling is present in CRSwNP patients, primarily in the stroma. This may contribute to features of airway remodeling previously described. PNECs from CRSwNP patients are induced to produce TGF-β1 and activin A by CSE and dsRNA, suggesting that cigarette smoke and viral infection might also contribute to airway remodeling.

The possible link between elevated serum levels of epithelial cell-derived neutrophil-activating peptide-78 (ENA-78/CXCL5) and autoimmunity in autistic children

Background

In autoimmune disorders, the underlying pathogenic mechanism is the formation of antigen-antibody complexes which trigger an inflammatory response by inducing the infiltration of neutrophils. Epithelial cell-derived neutrophil-activating peptide-78 (ENA-78) is a chemokine that recruits and activates neutrophils, thus it could play a pathogenic role in inflammation and autoimmune disorders. Some autistic children have elevated levels of brain specific auto-antibodies. We are the first to evaluate serum expression of ENA-78 and its relation to antineuronal auto-antibodies in autistic children.

Methods

Serum ENA-78 and antineuronal auto-antibodies were measured by ELISA test in 62 autistic children aged between 4–11 years and 62 health-matched controls.

Results

Serum levels of ENA-78 were significantly higher in autistic children than healthy controls (P < 0.001). Increased serum levels of ENA-78 have been found in 69.35% of autistic patients. In addition, autistic children had significantly higher percent positivity of serum antineuronal auto-antibodies (64.5%) than healthy controls (6.45%), P < 0.001. There was a significant positive association between the positivity of serum antineuronal auto-antibodies and the elevated levels of serum ENA-78 (P < 0.001) in autistic children.

Conclusions

Serum levels of ENA-78 were elevated in autistic children and they were significantly associated with the increased levels of serum antineuronal auto-antibodies. However, these data should be treated with caution until further research is conducted to determine the pathogenic role of ENA-78 in autism and its relation to brain specific auto-antibodies that have been found in some autistic children. The possible therapeutic role of ENA-78 antagonist in autistic children should be also studied.

Macrophage Infiltrate Is Elevated in CRSwNP Sinonasal Tissue Regardless of Atopic Status

Objective

Macrophages are major producers of inflammatory cytokines; however, their role in chronic rhinosinusitis (CRS) has not been clearly defined. The aim of this study was to quantify macrophages in sinus tissue of patients with various subtypes of CRS and determine the impact of atopic status on macrophage infiltrate.

Study Design

Prospective immunohistochemical study of human sinonasal tissue.

Setting

Academic medical center.

Subjects and Methods

Human sinonasal tissue was taken from patients with CRS with nasal polyposis (CRSwNP, n = 8), CRS without nasal polyposis (CRSsNP, n = 8), and controls (n = 8) undergoing surgery for CSF leak repair or endoscopic excision of non-secreting pituitary tumor. Samples were immunohistochemically stained for macrophage/monocyte markers Mac387 and CD68.

Results

CRSwNP patients had significantly increased numbers of Mac387 and CD68 cells compared to control patients ( P < .05) or CRSsNP patients ( P < .01). CRSsNP had significantly increased number of cells staining for CD68 compared to controls ( P < .05). The increased presence of macrophages measured by either marker in CRSwNP was independent of atopic status.

Conclusion

Macrophages are increased in CSRwNP patients regardless of atopic status and may contribute to the immunopathology of CRS.

Chronic sinusitis pathophysiology: the role of allergy

BACKGROUND

Chronic hyperplastic eosinophilic sinusitis (CHES) is an inflammatory disease characterized by eosinophil infiltration of sinus tissue that can present with and without nasal polyps (NPs). Aeroallergen sensitization in CHES occurs regularly, but the causality between allergen sensitivity, exposure, and disease is unclear.

METHODS

Allergen is unlikely to directly enter healthy sinuses either by diffusion or ciliary flow, and, even this is more problematic given the loss of patency of the ostia of diseased sinuses. Inflammation and tissue eosinophilia can develop secondary to allergen exposure in the nares, with systemic humoral recirculation of allergic cells including eosinophils, Th2 lymphocytes, and eosinophil precursors that are nonspecifically recruited back to the diseased sinuses.

RESULTS

The possibility of an allergic reaction to peptides derived from bacteria (i.e., Staphylococcus or superantigens) or fungi that colonize the diseased sinus also provides a plausible allergic mechanism.

CONCLUSION

Treatments of this disease include agents directed at allergic mediators such as leukotriene modifiers and corticosteroids, although this does not necessarily signify that an IgE-dependent mechanism can be ascribed. However, more recently, omalizumab has shown promise, including in patients without obvious aeroallergen sensitization. Although many aspects of the role of allergy in CHES remain a mystery, the mechanisms that are being elucidated allow for improved understanding of this disease, which ultimately will lead to better treatments for our patients who live daily with this disease.

Prominent role of IFN-γ in patients with aspirin-exacerbated respiratory disease

BACKGROUND

Aspirin-exacerbated respiratory disease (AERD) is distinguished from aspirin-tolerant asthma/chronic sinusitis in large part by an exuberant infiltration of eosinophils that are characterized by their overexpression of metabolic pathways that drive the constitutive and aspirin-induced secretion of cysteinyl leukotrienes (CysLTs).

OBJECTIVE

We defined the inflammatory milieu that in part drives CysLT overproduction and, in particular, the role of IFN-γ in the differentiation of eosinophils.

METHODS

Quantitative real-time PCR was performed for TH1 and TH2 signature cytokines on tissue from control subjects, patients with chronic hyperplastic eosinophilic sinusitis, and patients with AERD, and their cellular source was determined. The influence of IFN-γ on maturation, differentiation, and functionality of eosinophils derived from hematopoietic stem cells was determined.

RESULTS

Gene expression analysis revealed that tissue from both aspirin-tolerant subjects and patients with AERD display a TH2 cytokine signature; however, AERD was distinguished from chronic hyperplastic eosinophilic sinusitis by the prominent expression of IFN-γ. Intracellular and immunohistochemical cytokine staining revealed that the major sources of these cytokines were the eosinophils themselves. IFN-γ promoted the maturation of eosinophil progenitors, as measured by increased mRNA and surface expression of CCR3 and sialic acid-binding immunoglobulin-like lectin 8 (Siglec-8). Additionally, IFN-γ increased the expression of genes involved in leukotriene synthesis that led to increased secretion of CysLTs. IFN-γ-matured eosinophil progenitors were also primed, as demonstrated by their enhanced degranulation.

CONCLUSIONS

High IFN-γ levels distinguish AERD from aspirin-tolerant asthma and underlie the robust constitutive and aspirin-induced secretion of CysLTs that characterize this disorder.

Elevated serum levels of macrophage-derived chemokine and thymus and activation-regulated chemokine in autistic children

Background

In some autistic children, there is an imbalance of T helper (Th)1/Th2 lymphocytes toward Th2, which may be responsible for the induction of the production of autoantibodies in these children. Th2 lymphocytes express CCR4 receptors. CCR4 ligands include macrophage-derived chemokine (MDC) and thymus and activation-regulated chemokine (TARC). They direct trafficking and recruitment of Th2 cells. We are the first to measure serum levels of CCR4 ligands in relation to the degree of the severity of autism.

Methods

Serum concentrations of MDC and TARC were measured, by quantitative sandwich enzyme immunoassay technique, in 56 autistic children and 32 healthy matched children.

Results

Autistic children had significantly higher serum levels of MDC and TARC than healthy controls (P <0.001 and P <0.001, respectively). Children with severe autism had significantly higher serum levels of MDC and TARC than patients with mild to moderate autism (P <0.001 and P = 0.01, respectively). In addition, there were significant positive correlations between CARS and serum levels of both MDC (P <0.001) and TARC (P <0.001) in children with autism. There were significant positive correlations between serum levels of MDC and TARC in autistic children (P <0.001).

Conclusions

Serum levels of CCR4 ligands were elevated in autistic children and they were significantly correlated to the degree of the severity of autism. However, further research is warranted to determine the pathogenic role of CCR4 ligands in autism and to shed light on the therapeutic role of CCR4-ligand antagonism in autistic children.

Hypothetical pathogenesis of eosinophilic infiltration in Langerhans cell histiocytosis of the jaw

OBJECTIVE

The present study investigated the densities of mast cells and CCL-11/eotaxin-1 expression of tumor cells in Langerhans cell histiocytosis (LCH) of the jaw.

STUDY DESIGN

Eleven LCH cases arising in the jaws were selected. We evaluated eotaxin-1 expression in LCH cells via immunohistochemical staining. Toluidine blue was used to stain mast cells, with 20 periapical granuloma specimens serving as the control group.

RESULTS

In all 7 patients with multifocal LCH, jaw lesions were the earliest manifestation. Toluidine blue staining revealed that most of the mast cells involved in LCH were degranulated, and the number of mast cells in LCH lesions was not significantly higher than in periapical granulomas. Upon immunohistochemical examination, all patients but one showed positivity for eotaxin-1 in LCH cells.

CONCLUSION

This preliminary study suggests that eotaxin-1 expression in LCH cells may contribute to eosinophilic infiltration. Further studies of chemokine-receptor interactions will be needed to confirm this.

Leukotriene Inhibitors in Sinusitis

It has been recognized for many years that leukotrienes play an important role in mediating various effects of the allergic reaction. Recent evidence has shown that they play a role in other diseases including chronic sinusitis, particularly those sub-types involving eosinophils. Leukotrienes can be separated into the fairly well characterized cysteinyl leukotrienes and less well characterized leukotriene B(4). Effects of the leukotrienes are mediated through receptors that are expressed on a variety of cell types and can be modulated based on the inflammatory environment present. The pharmaceutical industry has long been interested in blocking leukotriene action and as such, two approaches have been developed that led to drugs approved for treatment of allergic disease. The most widely used class is the cysteinyl type 1 receptor antagonists, which block binding of the cysteinyl leukotrienes to the cell. The second class is an inhibitor of the 5-lipoxygenase enzyme that prevents synthesis of both the cysteinyl leukotrienes and leukotriene B(4). This review will focus on the role that leukotrienes play in chronic sinusitis and consider the rationale for choosing either a leukotriene antagonist or synthesis inhibitor as a treatment option. We will also discuss off-label uses for other medications that might be useful in these diseases as they relate to their ability to modulate leukotriene action.

Carbon dioxide-enriched water inhalation in patients with allergic rhinitis and its relationship with nasal fluid cytokine/chemokine release

BACKGROUND AND AIMS

Allergic rhinitis is characterized by eosinophil infiltration and accumulation in the nasal mucosa mainly due to IL-3, IL-5, and eotaxin activities. We undertook this study to investigate a possible in vivo effect of carbon dioxide-enriched water inhalation in patients with allergic rhinitis.

METHODS

Twenty five consecutive patients inhaled carbon dioxide-enriched water at Fonti di Rabbi Spa Centre (Trento, Italy). Symptom scores for nasal obstruction, itching and sneezing were obtained before and after treatment. Nasal lavage was collected, and IL-3, IL-5, and eotaxin levels were assessed using the quantitative sandwich enzyme immunoassay technique. Cytometric analysis was performed on samples to measure total cell count, CD45+ cells, and percentages of polymorphonucleates and lymphocytes.

RESULTS

There were statistically significant differences in chemokine levels and in cell populations between patients and healthy controls before treatment. After carbon dioxide-enriched water inhalation, we observed statistically significant improvements in symptom scores, chemokine levels, and percentages of cell populations.

CONCLUSIONS

Our results seem to confirm the role of IL-3, IL-5, and eotaxin in the pathophysiology of allergy and the beneficial effect of carbon dioxide-enriched water inhalation in patients affected by allergic rhinitis.

Genetics and phenotyping in chronic sinusitis

Chronic sinusitis with nasal polyposis historically has been treated as a single monolithic clinical disorder. Just as asthma is now accepted as numerous heterogeneous diseases, chronic sinusitis should also be viewed as comprising several diseases with varying causes, with each one characterized by distinct histologic and gene and protein expression patterns. This includes recognition of the need to define these diseases based on the presence or absence of an eosinophilic infiltrate but also on additional distinctions based on unique agents that drive their development and perpetuation. As a collection of heterogeneous diseases, proper differential diagnosis is required to delineate appropriate therapeutic intervention. This review will focus on recognized distinct presentations of chronic sinus disease, including distinguishing the clinical presentations, cellular and molecular characteristics, genetic differences, and current treatment options for each.

Increased expression of the chemokine CCL23 in eosinophilic chronic rhinosinusitis with nasal polyps

BACKGROUND

Chronic rhinosinusitis (CRS) is a heterogeneous chronic disease characterized by local inflammation of the sinonasal tissues. The pathogenesis of CRS remains controversial, but it has been associated with the accumulation of various immune and inflammatory cells in sinus tissue.

OBJECTIVES

The objective of this study was to investigate the expression of the chemokine CCL23, which is known to bind to CCR1 and recruit monocytes, macrophages, and dendritic cells, in patients with CRS.

METHODS

We collected nasal tissue from patients with CRS and control subjects. We assayed mRNA for CCL23 by using real-time PCR and measured CCL23 protein by means of ELISA, immunohistochemistry, and immunofluorescence.

RESULTS

CCL23 mRNA levels were significantly increased in nasal polyps (NPs) from patients with CRS with nasal polyps (CRSwNP; P < .05) compared with inferior turbinate and uncinate tissue from patients with CRS or control subjects. CCL23 protein levels were also increased in NPs, although these levels were not statistically significant. Immunohistochemical analysis revealed CCL23 expression in mucosal epithelial cells and inflammatory cells, but accumulation of CCL23(+) inflammatory cells occurred only in NPs. Immunofluorescence data showed CCL23 colocalization with eosinophil cationic protein-positive eosinophils. The concentration of CCL23 in NPs positively correlated with the concentration of eosinophil cationic protein, suggesting that eosinophils are major CCL23-producing cells in NPs. Finally, we found that CCL23 protein levels were significantly increased in NPs from patients with CRSwNP with aspirin sensitivity.

CONCLUSION

Overproduction of CCL23 in NPs might contribute to the pathogenesis of eosinophilic CRSwNP through the recruitment of CCR1(+) inflammatory cells, including monocytes and macrophages, and the amplification of local inflammation.

CC chemokine receptor 4 (CCR4) in human allergen-induced late nasal responses

BACKGROUND

CC Chemokine receptor 4 (CCR4) is preferentially expressed on Th2 lymphocytes. CCR4-mediated inflammation may be important in the pathology of allergic rhinitis. Disruption of CCR4 - ligand interaction may abrogate allergen-induced inflammation.

METHODS

Sixteen allergic rhinitics and six nonatopic individuals underwent both allergen and control (diluent) nasal challenges. Symptom scores and peak nasal inspiratory flow were recorded. Nasal biopsies were taken at 8 h post challenge. Sections were immunostained and examined by light or dual immunofluorescence microscopy for eosinophils, T-lymphocytes, CCR4(+)CD3(+) and CXCR3(+)CD3(+) cells and examined by in situ hybridization for CCR4, IL-4 and IFN-gamma mRNA(+) cells. Peripheral blood mononuclear cells were obtained from peripheral blood of nine normal donors and the CCR4(+)CD4(+) cells assessed for actin polymerization in response to the CCR4 ligand macrophage-derived chemokine (MDC/CCL22) and the influence of a CCR4 antagonist tested.

RESULTS

Allergic rhinitics had increased early and late phase symptoms after allergen challenge compared to diluent; nonatopics did not respond to either challenge. Eosinophils, but not total numbers of CD3(+) T cells, were increased in rhinitics following allergen challenge. In rhinitics, there was an increase in CCR4(+)CD3(+) protein-positive cells relative to CXCR3(+)CD3(+) cells; CCR4 mRNA+ cells were increased and IL-4 increased to a greater extent than IFN-gamma. CCR4(+)CD4(+) T cells responded to MDC in vitro, and this response was inhibited by the selective CCR4 antagonist.

CONCLUSION

Lymphocyte CCR4 expression is closely associated with induction of human allergen-induced late nasal responses. Blocking CCR4-ligand interaction may provide a novel therapeutic approach in allergic disease.

Relationships between eosinophilic inflammation, tissue remodeling, and fibrosis in eosinophilic esophagitis

The clinical and pathologic features of eosinophilic esophagitis (EE) include extensive tissue remodeling. Increasing evidence supports a key role for the eosinophil in multiple aspects of the esophageal remodeling and fibrosis seen in this allergic disease. This article reviews the clinical implications of esophageal remodeling and fibrosis in EE and discusses the possible pathogenic mechanisms inducing and regulating these responses. The focus is specifically on eosinophil and cytokine interactions with the esophageal epithelium, vascular endothelium, resident fibroblasts, and smooth muscle. Current and potential therapeutic interventions are discussed that may impact the development or resolution of chronic esophageal remodeling and fibrosis in EE.

Pre-exposure to Staphylococcal enterotoxin A exacerbates the pulmonary allergic eosinophil recruitment in rats

Gram-positive Staphylococcus aureus releases classical enterotoxins which aggravates allergic airway diseases. However, little is known about the mechanisms underlying the cell influx exacerbation in asthmatic individuals under exposure to Staphylococcal enterotoxins. We therefore aimed to investigate the effects of airways exposure to Staphylococcal enterotoxin A (SEA) to pulmonary leukocyte recruitment in rats sensitized and challenged with ovalbumin (OVA). Rats were exposed to SEA at 4h prior to OVA challenge or at 4h post-OVA challenge. Bronchoalveolar lavage (BAL) fluid, bone marrow and lung tissue were obtained at 24h after OVA challenge. Pre-exposure to SEA markedly enhanced the eosinophil counts in both BAL fluid and pulmonary tissue in OVA-challenged rats, whereas neutrophil and mononuclear cell counts remained unchanged. In bone marrow, pre-exposure to SEA alone significantly increased the number of eosinophils, and that was further increased in OVA-challenged rats. Exposure to SEA post-OVA challenge did not affect the number of eosinophils, neutrophils and mononuclear cells in BAL fluid. Pre-exposure to the endotoxin lipopolyssacharide (LPS) in OVA-challenged animals rather enhanced the neutrophil number in BAL fluid. In rats pre-exposed to SEA and OVA-challenged, a marked elevation in the levels of TNF-alpha and eotaxin (but not of IL-10) in BAL fluid was observed. The eotaxin levels increased by about of 3-fold in alveolar macrophages treated with SEA in vitro. In conclusion, airways pre-exposure to SEA causes a selective increase in eosinophil number in BAL fluid and bone marrow of OVA-challenged rats by mechanisms involving enhancement of TNF-alpha and eotaxin synthesis.

Current Thinking on the Relationship Between Rhinosinusitis and Asthma

An observation made initially on clinical grounds and epidemiologic evidence, i.e., that rhinosinusitis and asthma are closely linked diseases is now supported by a growing body of scientific evidence. Most recent evidence supports the characterization of rhinosinusitis and asthma as two compartmental expressions of a common mucosal susceptibility to exogenous stimuli. In addition, there is evidence that the compartmental processes can affect and amplify each other via a systemic intermediary. The bone marrow is involved in this process, and IL-5 may be a key cytokine for orchestrating the systemic interaction. These facts argue that rhinosinusitis and asthma are not simply localized disease processes but part of a systemic inflammatory disease affecting the respiratory tract. They also provide a compelling rationale for combined treatment strategies with consideration of the treatment of rhinosinusitis as a means of improving asthma control and monitoring for signs of bronchial involvement in those with rhinosinusitis.

Eotaxin-1, -2, and -3 immunoreactivity and protein concentration in the nasal polyps of eosinophilic chronic rhinosinusitis patients

OBJECTIVES/HYPOTHESIS

Eosinophilic chronic rhinosinusitis (CRS) is characterized by the accumulation of numerous eosinophils in the sinus mucosa and nasal polyps, which are frequently difficult to control, even with surgery. The present study was designed to evaluate the expression and localization of eotaxins, which are well known to be potent and selective chemoattractants for eosinophils in CRS.

STUDY DESIGN

Randomized study.

METHODS

The patients were classified into eosinophilic and noneosinophilic groups. Histopathological profiles of the nasal polyp were observed with hematoxylin-eosin staining. Eotaxin-1, -2, and -3 were immunohistochemically stained in the nasal polyps. Furthermore, the protein content of eotaxin subtypes inside the nasal polyp and sinus effusion was measured using enzyme-linked immunosorbent assay (ELISA).

RESULTS

In the nasal polyps, immunoreactivities of the eotaxin subfamily, eotaxin-1, -2, and -3, were noted in most of the infiltrating eosinophils, as well as in other inflammatory cells, epithelial cells, and endothelial cells. Compared with noneosinophilic CRS groups, eosinophilic CRS groups had a significant expression of eotaxins in their eosinophils. The eotaxin concentrations of nasal polyp and sinus effusion as measured by ELISA were significantly increased in the eosinophilic CRS group compared to the noneosinophilic CRS group.

CONCLUSIONS

The present findings suggest that enhanced eotaxin family production by eosinophils results in the recruitment of eosinophils into the tissue by a self-amplifying process. Laryngoscope, 2009.

Alteration of mitochondrial DNA sequence and copy number in nasal polyp tissue

This study was designed to investigate the possibility that mtDNA mutations might arise in inflammatory or chronically damaged nasal polyp tissue from 23 patients. Thirteen patients (57%) displayed nasal polyp tissue-specific mtDNA mutations in the hypervariable segment of the control region and cytochrome b gene, which were not found in the corresponding blood cells and/or adjacent normal tissue. Nasal polyp tissue-specific length heteroplasmic mutations were also detected in nucleotide position (np) 303-315 homopolymeric poly C track (39%), np 514-523 CA repeats (17%) and np 16184-16193 poly C track (30%). The average mtDNA copy number was about three times higher in nasal polyp tissue than in the corresponding peripheral blood cells and adjacent non-polyp tissues. The level of reactive oxygen species (ROS) was significantly higher in the nasal polyp tissues compared to those from the corresponding samples. High level of ROS in nasal polyp tissue may contribute to development of mtDNA mutations, which may play a crucial role in the vicious cycle of pathophysiology of nasal polyps.

Serum concentrations of CCR4 ligands in relation to clinical severity of atopic dermatitis in Egyptian children

T helper 2 (Th2) lymphocytes, the key effector cells in pathogenesis of atopic dermatitis (AD), express CCR4 receptors. CCR4 ligands (macrophage-derived chemokine 'MDC' and thymus and activation-regulated chemokine 'TARC') direct trafficking and recruitment of Th2 cells into lesional skin in AD. These chemokines appear to be useful inflammatory markers for assessing severity of AD in adults. However, the same results have not been replicated in children. Therefore, we were stimulated to elucidate the expression of CCR4 ligands in children with AD and their relation to clinical disease severity. To investigate this, serum concentrations of CCR4 ligands were determined in 60 children, of whom 30 had AD and 30 were healthy matched subjects. Patients were classified into mild (n = 8), moderate (n = 12) and severe (n = 10) according to the objective scoring AD (obj-SCORAD) index. Serum concentrations of MDC and TARC were significantly increased in children with AD (2697 +/- 982.6 pg/ml and 945.5 +/- 494.7 pg/ml, respectively) compared with controls (357.2 +/- 233.2 pg/ml and 214.2 +/- 116.6 pg/ml, respectively, p < 0.0001). Serum levels of both chemokines went hand in hand with disease severity as they were significantly higher in severe than moderate and in moderate than mild AD. In addition, they correlated positively with obj-SCORAD (r = 0.99 for both, p < 0.0001). Furthermore, both chemokines had significant positive correlations to blood eosinophil counts and serum immunoglobulin E. In conclusion, serum CCR4 ligands may be useful inflammatory markers for assessing AD severity in children. Further studies may pave way for CCR4 ligands antagonism among the adjuvant therapeutic strategies of AD.

Human eosinophil adhesion and degranulation stimulated with eotaxin and RANTES in vitro: lack of interaction with nitric oxide

Background

Airway eosinophilia is considered a central event in the pathogenesis of asthma. The toxic components of eosinophils are thought to be important in inducing bronchial mucosal injury and dysfunction. Previous studies have suggested an interaction between nitric oxide (NO) and chemokines in modulating eosinophil functions, but this is still conflicting. In the present study, we have carried out functional assays (adhesion and degranulation) and flow cytometry analysis of adhesion molecules (VLA-4 and Mac-1 expression) to evaluate the interactions between NO and CC-chemokines (eotaxin and RANTES) in human eosinophils.

Methods

Eosinophils were purified using a percoll gradient followed by immunomagnetic cell separator. Cell adhesion and degranulation were evaluated by measuring eosinophil peroxidase (EPO) activity, whereas expression of Mac-1 and VLA-4 was detected using flow cytometry.

Results

At 4 h incubation, both eotaxin (100 ng/ml) and RANTES (1000 ng/ml) increased by 133% and 131% eosinophil adhesion, respectively. L-NAME alone (but not D-NAME) also increased the eosinophil adhesion, but the co-incubation of L-NAME with eotaxin or RANTES did not further affect the increased adhesion seen with chemokines alone. In addition, L-NAME alone (but not D-NAME) caused a significant cell degranulation, but it did not affect the CC-chemokine-induced cell degranulation. Incubation of eosinophils with eotaxin or RANTES, in absence or presence of L-NAME, did not affect the expression of VLA-4 and Mac-1 on eosinophil surface. Eotaxin and RANTES (100 ng/ml each) also failed to elevate the cyclic GMP levels above baseline in human eosinophils.

Conclusion

Eotaxin and RANTES increase the eosinophil adhesion to fibronectin-coated plates and promote cell degranulation by NO-independent mechanisms. The failure of CC-chemokines to affect VLA-4 and Mac-1 expression suggests that changes in integrin function (avidity or affinity) are rather involved in the enhanced adhesion.

Role of matrix metalloproteinases in chronic rhinosinusitis

PURPOSE OF REVIEW

In this review, we discuss the role of matrix metalloproteinases and the potential therapeutic inhibition of metalloproteinases in chronic rhinosinusitis. Metalloproteinases control tissue remodelling along with several other physiologic processes. Failures may cause extracellular matrix deposition and sustained inflammation, which are common features in chronic rhinosinusitis.

RECENT FINDINGS

Metalloproteinases are rarely studied in chronic rhinosinusitis. Upregulation of certain metalloproteinases (gelatinases, collagenases and matrilysin) is described in the literature. The results are partly controversial, suggesting that metalloproteinases are implicated in the destructive processes in the disease pathogenesis, but also demonstrate that they may exert an anti-inflammatory function in chronic rhinosinusitis. The imbalance between metalloproteinases and the tissue inhibitor of metalloproteinases is proposed to be crucial in the extracellular matrix deposition in asthma, and it may also lead to pathologic tissue remodelling in chronic rhinosinusitis.

SUMMARY

Metalloproteinases are implicated in the chronic respiratory-tract diseases, but little is known about their detailed functions in disease pathogenesis. Metalloproteinases may serve as tools in evaluating prognosis and provide a target for novel therapies, highlighting the need for better understanding of metalloproteinase functions in chronic rhinosinusitis.

Ontogeny of the eotaxins in human lung

The ontogeny of the C-C chemokines eotaxin-1, eotaxin-2, and eotaxin-3 has not been fully elucidated in human lung. We explored a possible role for eotaxin in developing lung by determining the ontogeny of eotaxin-1 (CCL11), eotaxin-2 (CCL24), eotaxin-3 (CCL26), and the eotaxin receptor, CCR3. We tested discarded surgical samples of developing human lung tissue using quantitative RT-PCR (QRT-PCR) and immunostaining for expression of CCL11, CCL24, CCL26, and CCR3. We assessed possible functionality of the eotaxin-CCR3 system by treating lung explant cultures with exogenous CCL11 and analyzing the cultures for evidence of changes in proliferation and activation of ERK1/2, a signaling pathway associated with CCR3. QRT-PCR analyses of 22 developing lung tissue samples with gestational ages 10-23 wk demonstrated that eotaxin-1 mRNA is most abundant in developing lung, whereas mRNAs for eotaxin-2 and eotaxin-3 are minimally detectable. CCL11 mRNA levels correlated with gestational age (P < 0.05), and immunoreactivity was localized predominantly to airway epithelial cells. QRT-PCR analysis detected CCR3 expression in 16 of 19 developing lung samples. Supporting functional capacity in the immature lung, CCL11 treatment of lung explant cultures resulted in significantly increased (P < 0.05) cell proliferation and activation of the ERK signaling pathway, which is downstream from CCR3, suggesting that proliferation was due to activation of CCR3 receptors by CCL11. We conclude that developing lung expresses the eotaxins and functional CCR3 receptor. CCL11 may promote airway epithelial proliferation in the developing lung.

Does the prevalence of nasal polyps increase in patients using statins?

Several statins inhibit T-helper 1 development and induce T-helper 2 polarization and production of T-helper 2 cytokines that promote the activation and chemotaxis of eosinophils. Whether statins promote the development of nasal polyps has so far been uncertain. No studies have evaluated the frequency of the development of nasal polyps in patients using statins. To better define the relationship of statin use to the presence of nasal polyps, the investigators explored the frequency of the development of nasal polyps in patients who were using statins. A total of 200 patients who were using statins and 200 who were not using statins (400 cases) were investigated. All patients were examined for nasal polyps by anterior rhinoscopy or investigation with a fiberoptic endoscope. In addition, immunoglobulin E levels were measured, a skin prick test was performed, and the results from the 2 groups were compared. Nasal polyps were detected in 4 subjects who were using statins, whereas 5 nasal polyps were found in the control group; differences between the 2 groups were statistically insignificant (P>.05). When the atopy status of the 2 groups was compared, prick test positivity and serum immunoglobulin E levels were found to be 15% and 44+/-31 IU/mL in the statin group and 19% and 68+/-23 IU/mL in the control group (P>.05). These results show that nasal polyposis is a multifactorial disease with several different causes; however, the frequency of the development of nasal polyps does not increase in patients who use statins.

The Prevalence and Effect of Asthma on Adults with Chronic Rhinosinusitis

We conducted a retrospective review of 145 consecutively presenting adults treated for chronic rhinosinusitis (CRS) in a tertiary care institution. Our goals were to determine (1) the prevalence of asthma in these patients, (2) the prevalence of specific CRS symptoms in both asthmatic and nonasthmatic patients, and (3) the frequency of surgical treatment for CRS in patients with and without asthma. We found that asthma was present in 23.4% of CRS patients, a much higher rate than the 5% prevalence of asthma in the general adult population. Patients with asthma had a significantly higher prevalence of nasal polyps (47 vs. 22%; p = 0.004), olfactory dysfunction (26 vs. 6%; p = 0.001), and nasal congestion (85 vs. 60%; p = 0.027) than did those without asthma. Patients without asthma had a significantly higher prevalence of headache (72 vs. 53%; p = 0.037) and rhinorrhea (58 vs. 38%; p = 0.047). The prevalence of postnasal drip and environmental allergies in the two groups was similar. Although the difference between the proportions of patients with and without asthma who required primary sinus surgery was not statistically significant (76 vs. 64%; p = 0.175), patients with asthma did require significantly more revision sinus procedures overall (mean: 2.9 vs. 1.5; p = 0.003).

Eosinophil infiltration and activation in nasal polyposis

Conclusions. Infiltration and activation of eosinophils is a characteristic of nasal polyposis. Allergic reaction is a risk factor for the accumulation of eosinophils in this disease. T-cell-derived interleukin 5 (IL-5) and autosecretion of IL-5 from activated eosinophils may be causative reasons for the extension and persistence of eosinophil inflammation. Objectives. To investigate whether eosinophils were accumulated and activated in nasal polyposis, and the roles of IL-5, eotaxin, and T cells in this process. Materials and methods. A retrospective study was conducted on 17 tissue samples from patients with nasal polyposis with allergy and 26 cases of non-allergic polyposis. Immunohistochemical staining by specific antibodies was carried out using the alkaline phosphatase anti-alkaline phosphatase method and the avidin-biotin complex technique.Results. The number of EG1-positive cells (pan eosinophil marker) was similar to the number of EG2-positive cells (activated eosinophil marker) in all tissue samples, although EG1- and EG2-positive cells were richer in allergic patients than those in non-allergic patients. Both EG1- and EG2-positive cells were correlated with CD3-positive cells (pan T cell marker) and IL-5-producing cells in allergic or non-allergic polyposis. A large proportion of IL-5 producing cells were eosinophils. Eotaxin protein was detected in all tissue samples and dominantly located in epithelial cells. Eotaxin expression between allergic and non-allergic subjects was not significantly different.

Interactions between eotaxin and interleukin-5 in the chemotaxis of primed and non-primed human eosinophils

This study was designed to understand the relationship between interleukin-5 and eotaxin in modulating the chemotaxis of eosinophils obtained from healthy subjects and subjects with allergic rhinitis. Chemotaxis of eosinophils from patients with allergic rhinitis toward interleukin-5 (0.25 ng/ml) was 78% higher than that of healthy subjects. Incubation of eosinophils with eotaxin (100 ng/ml) did not change the interleukin-5-induced chemotaxis of eosinophils from healthy subjects, but it reversed the enhanced chemotaxis seen in eosinophils from allergic patients. Chemotaxis of eosinophils from patients with allergic rhinitis toward eotaxin (100 ng/ml) was 65% higher than that of eosinophils from healthy subjects. Incubation of eosinophils with interleukin-5 (100 ng/ml) significantly increased the eotaxin-induced chemotaxis in both subject groups, but such increases were markedly higher for cells from patients with allergic rhinitis. Our finding that eotaxin inhibits the enhanced eosinophil chemotaxis toward interleukin-5 in primed cells suggests that this chemokine may downregulate eosinophil accumulation in the nasal mucosa of allergic patients.

The relationship between rhinosinusitis and asthma sinusitis

Chronic sinusitis comprises numerous disorders characterized by inflammation, mucous gland hyperplasia, and remodeling. Chronic hyperplastic eosinophilic sinusitis (CHES) is characterized by unrestrained proliferation of eosinophils, Th2-like lymphocytes, fibroblasts, goblet cells, and mast cells. The pathology of CHES is similar to that of asthma, and it is frequently diagnosed in association with asthma. It has been reported that exacerbations of CHES occur temporally with worsening of asthma; however, in the absence of well-controlled studies, this linkage remains unproven. In this article, the potential mechanisms linking these two diseases are examined.

Effects of cryptoporus polysaccharide on rat allergic rhinitis associated with inhibiting eotaxin mRNA expression

Aqueous extract from the fruiting body of Cryptoporus volvatus has been reported to present anti-tumor, anti-allergy, anti-inflammation and immunomodulatory activities. However, the effect mechanisms of anti-allergy and anti-inflammation are poorly understood. The aim of study is to evaluate whether Cryptoporus polysaccharides (CP) extracted from fruiting body of Cryptoporus volvatus decrease the development of nasal symptoms, airway hyperresponsiveness (AHR) to methacholine (MCh) and the infiltration of eosinophils in nasal mucosa in rat model of allergic rhinitis, and investigate a possible action mechanism of CP by detecting the expression of eotaxin mRNA in nasal mucosa and lung tissues. Rats were immunized with ovalbumin and consecutive topical antigen instillation was performed. Repeated intranasal ovalbumin challenge caused rhinitis symptom, AHR to MCh, eosinophil infiltration and histological alterations into the nasal mucosa and increase of eotaxin mRNA expression in nasal mucosa and lung tissue were examined. Pretreatment with CP 3, 9 and 27 mg kg(-1) (ig) decreased the numbers of sneezing 27.4%, 38.4% and 44.3% and nasal rubbing 27.5%, 34.9% and 47.7% comparison with model group, respectively. CP caused a dose-related inhibition of MCh-induced AHR. CP 27 mg kg(-1) decreased the expression of eotaxin mRNA in the nasal mucosa by 35%. These results suggest CP can relieve the symptom, eosinophil infiltration and injury of tissue in nasal mucosa and lung tissue and AHR of allergic rhinitis in rats. Its action mechanism may be associated with the decrease of eotaxin mRNA expression.

Fungi in chronic hyperplastic eosinophilic sinusitis: reasonable doubt

Chronic hyperplastic eosinophilic sinusitis (CHES) is a T-helper (Th)2-like, lymphocyteinitiated, eosinophil-rich inflammatory disease. The complex immune interactions required to orchestrate these processes begin with the presentation of antigen by mature dendritic cells to Th lymphocytes that display the appropriate antigen-specific T-cell receptor. The objective of sinus research must be to identify and target that antigen; this will lead to the cure for this condition. This article reviews numerous models that may be responsible for the pathophysiology of this disorder, including putative roles for allergens, bacteria, and bacterial-derived superantigens, as well as recent interest in fungal-derived antigens. Additionally, we speculate that whatever the inciting cause of CHES may be, it is plausible that once initiated, cellular differentiation pathways may lead to the development of an antigen-independent permanent phase. More than one of these may be valid in different subjects and, furthermore, this list almost assuredly does not explain all cases of CHES. The concept that fungal antigens colonizing the sinuses are responsible for CHES represents an intriguing, but unproven, hypothesis. Presently, the case for the fungus remains circumstantial. The case for fungi will be proved only with definitive proof that T-cells within the sinuses are actively responding to fungal antigens present in the sinus and with the further demonstration that removal of those fungal antigens ameliorates the disease.

Effects of ciclamilast, a new PDE 4 PDE4 inhibitor, on airway hyperresponsiveness, PDE4D expression and airway inflammation in a murine model of asthma

PDE4 (phosphodiesterase-4) plays a critical role in pathogenesis of allergic asthma and chronic obstructive pulmonary disease (COPD). PDE4 inhibitors are presently under clinical development for the treatment of asthma and/or COPD. Ciclamilast, a new PDE4 inhibitor, is a piclamilast (RP 73401) structural analogue, but has a more potent inhibitory effect on PDE4 and inflammation in the airway tissues and less side effects than that of piclamilast. In this study, we elucidate primarily on the roles of compound on PDE4 enzyme in physiological and pathological processes in a mouse model of asthma. The sensitized/challenged mice were reexposed to ovalbumin and airway response to inhaled methacholine was monitored. Orally administration of ciclamilast, in a dose-dependent manner, significantly inhibited changes in lung resistance and lung dynamic compliance, as well as upregulation of cAMP-PDE activity, increase of PDE4D mRNA expression, but not PDE4B from lung tissue in the murine model. In addition, the compound dose-dependently reduced mRNA expression of eotaxin, tumor necrosis factor (TNF)-alpha and interleukin (IL)-4, but slightly increased mRNA expression of interferon (IFN)-gamma from lung tissue. Further, levels of eotaxin, TNF-alpha and IL-4, and eosinophil and neutrophil accumulation in bronchoalveolar lavage fluid were also significantly reduced. Pathological examination, goblet cell hyperplasia and inflammatory cells infiltration in lung tissue were suppressed by treatment with ciclamilast. A significant correlation was observed between the increases in PDE4D mRNA expression and airway hyperresponsiveness. These studies confirm that inhibitory effect of ciclamilast on airway hyperresponsiveness includes its inhibiting PDE4D mRNA expression, down-modulating PDE4 activity, anti-inflammation and anti-mucus hypersecretion, and ciclamilast may have therapeutic potential for the treatment of asthma.