Update on the molecular biology of nasal polyposis

The definition of CRS with and without nasal polyposis continues to evolve. It may require an understanding of a broader range of etiologies and pathogenesis than bacterial or viral infection. One must know whether the inflammation is of infectious or noninfectious origin. Therapeutic options will include pharmacotherapies and surgery. The pharmacotherapeutic approach will include antibiotics, systemic and topical steroids, possibly antifungals, novel anti-inflammatory therapies such as the use of antibodies directed against inflammatory cytokines and antileukotrienes, and perhaps low-dose macrolide therapy. In the case of massive nasal polyposis, modern surgical techniques will have to be performed before these therapeutic options will be possible. Finally, the use of topical diuretics such as amiloride and furosemide has been studied and the initial responses seem to be encouraging.

Chronic rhinosinusitis and superantigens

This article discusses the potential role of bacterial superantigens (SAgs) in chronic rhinosinusitis with nasal polyposis (CRS/NP). First, it briefly describes SAgs, focusing on how they interact with the immune system by binding to T-cell receptors (TCR) and major histocompatibility complex (MHC) class II molecules. Second, it discusses the role of SAgs in other chronic inflammatory diseases.Finally, it presents evidence for the role of SAgs in the pathogenesis and maintenance of CRS/NP focusing on current research and future considerations.

[Etiology of nasal polyps: an update]

Nasal polyps are the results of chronic inflammation of nasal mucosa. Ethiopathology of nasal polyposis is still unclear and investigated. The main aim of this study was the assessment of interleukin 2 (IL-2), 4 (IL-4) and 13 (IL-13) and interferon gamma (IFN-gamma) expressions in two groups of patients with nasal polyps: non-allergic and allergic to dust. Twelve patients with nasal polyposis were selected, six of them allergic and six non-allergic. Patients with allergy were distinguished from those without allergy on the basis of positive allergy skin tests to dust and serum levels of IgE. Blood sample was obtained from patients and examined for the expression of Interleukin 2, 4, and 13 and IFN-gamma by intracellular staining procedure after stimulation with PMA/ionomycin (phorbol 12-myristate 13-acetate) and allergen (D. pteronyssimus, Allergopharma). Negative correlation was found between expression of Interleukin 2, 4, 13 after PMA/ionomycin and allergen stimulation (p > 0.05) into two groups. Although mean expression of IFN-gamma and IL-2 were lower in allergic patients with nasal polyps. Mean value of IL-4 and IL-13 were higher in allergic patients in comparison to non-allergic, but the correlations were not significant. We did not find correlations between expression of investigated interleukins and bronchial asthma and ASA-intolerance existed in patients (p > 0.05). We found that expression of IFN-gamma was significantly lower in patients with polyps recurrences followed by polypectiomies (p = 0.05). In patients who used intranasal local steroid before treatment we observed significant decrease of 11-2 and 11-13 levels after allergen stimulation (p = 0.,034, p = 0.023). No specific differences of expression of investigated cytokines between allergic versus non-allergic patients suggests that the allergic mechanism may not play an fundamental role in the aetiology and formation of nasal polyps. Furthermore local steroids seem to be used in every patient after polypectomy because of their anti-inflammatory stimulation.

Inflammatory nasal polyps: an unusual late complication of Silastic sheet repair of orbital floor fracture

Silastic implants are very widely used in surgical practice and are considered to be relatively inert. They do however present with complications, including infection, local foreign body inflammatory response, calcification, migration and failure of repair of the defect, which sometimes may necessitate explantation. Head and neck implants do present a special case, as complications can cause obstruction and disruption of function in small cavities. A pertinent history, clinical review and computed tomography scan are usually invaluable in obtaining a diagnosis. We present a rare case of migrated Silastic orbital sheet, presenting as a nasal polyp and causing maxillary antral pain and infection. A detailed search of the medical literature revealed no other such case.

Chronic rhinosinusitis and recurrent nasal polyps in two children with IgG subclass deficiency and review of the literature

Chronic rhinosinusitis (CRS) is a chronic inflammatory disorder of mucosa of the nose and the paranasal sinuses. Two major forms of CRS can be differentiated; CRS with nasal polyps (CRSwNP) and CRS without nasal polyps (CRSsNP). The pathophysiology and etiology of nasal polyps (NPs) are partly understood. IgG subclass deficiency was shown to be associated with an increased susceptibility to infections. However the association between NPs and IgG subclass deficiency has never been reported.

OBJECTIVES

To report two cases of recalcitrant CRS and recurrent NPs with IgG subclass deficiency.

CASE REPORT

Two children (6 and 8 year-old boys) were referred to the Pediatric Allergy/Immunology Clinic, Siriraj Hospital due to a prolonged history of CRS and recurrent NPs. Both of them were treated with aggressive medical (topical and systemic corticosteroids, antibiotics, leukotriene antagonist, nasal irrigation) as well as surgical therapy, without significant improvement. Immunologic investigation in both patients showed that IgG, IgA, and IgM level were normal. IgG subclasses level in patient No. 1 were IgG1 1,235 (280-1120) mg/dl (79%), IgG2 235 (30-630) mg/dl (23.5%), IgG3 27.3 (40-250) mg/dl (1.74%), and IgG4 92.4 (11-620) mg/dl (5.9%). IgG subclasses level in patient No. 2 were IgG1 1,139 (280-1120) mg/dl (82.5%), IgG2 170 (30-630) mg/dl (12.3%), IgG3 5.6 (40-250) mg/dl (0.4%), IgG4 65.7 (11-620) mg/dl (4.8%). The diagnosis of CRS and recurrent NPs with IgG3 subclass deficiency in the first patient and IgG2/IgG3 subclass deficiency in the second patient were made. Patient No. 1 was given monthly IVIG therapy for the total of 7 courses and medications were gradually tapered. Currently, the patient is doing well after the cessation of IVIG therapy for 3 months. Patient No. 2 denied the IVIG treatment and was lost to follow up.

CONCLUSION

We reported two cases of recalcitrant CRS and recurrent NPs in children. Immunologic work up revealed IgG subclass deficiency. The treatment with monthly IVIG improved CRS and NPs in treated patient which brought up the possibility of association between NPs and IgG subclass deficiency. Further study on the direct role of IVIG in NPs will be needed in the future.

Bacterial induction of TNF-alpha converting enzyme expression and IL-6 receptor alpha shedding regulates airway inflammatory signaling

Airway epithelial cells have a major role in initiating inflammation in response to bacterial pathogens. Through the immediate induction of CXCL8 and cytokine expression, polymorphonuclear cells are mobilized and activated to eradicate the infecting organisms. However, the influx of polymorphonuclear cells and the effects of their toxic exoproducts impede respiratory function. We postulated that respiratory epithelial cells must also participate in the regulation of their own proinflammatory signaling. Both Staphylococcus aureus and Pseudomonas aeruginosa were found to potently activate IL-6 expression immediately upon contact with epithelial cells, and by 1 h induced TNF-alpha converting enzyme (TACE) transcription. By 4 h of bacterial exposure, TACE colocalized with IL-6Ralpha on the apical surface of airway cells, and by 24 h, soluble IL-6Ralpha accumulated in the cell culture supernatant. Epithelial IL-6 and soluble IL-6Ralpha were shown to participate in trans-signaling, interacting with membrane-associated gp130 to activate CCL-2 expression and inhibit additional CXCL8 production. Thus, bacteria are physiological activators of TACE expression, which provides a mechanism to regulate inflammatory signaling that is initiated by airway epithelial cells.

[The role of chosen cytokines in etiology of nasal polyps]

Nasal polyposis is a chronic inflammatory disease of the nasal mucus. The pathogenesis of nasal polyps is still not entirely known and has been debated for many years. The aim of the present study was to evaluate the expression of interleukins 2 and 4 in patients with nasal polyps and to compare cytokine profile of patients with allergy versus patients without allergy.

MATERIAL AND METHODS

Twelve patients with nasal polyps were selected, six of them allergic to dust and six non-allergic. Patients with allergy were distinguished from those without allergy on the basis of positive allergy skin test to dust and the serum levels of IgE. Blood sample was obtained from patients and examined for the expression of Interleukin 2 and 4 by intracellular staining procedure, after stimulation with PMA (phorbol 12-myristate 13-acetate) and allergen (D. pteronyssimus, Allergopharma).

RESULTS

Statistical analysis of 2 groups of patients demonstrated that no significant difference in the interleukins expression in allergic versus non-allergic patients was observed (p > 0.05). In patients who used intranasal local steroid before treatment we observed significant decrease of 11-2 level after allergen stimulation (p = 0.034).

CONCLUSION

No differences of expression of Interleukin-4 between allergic versus non-allergic patients suggests that the allergic mechanism does not play an important role in the aetiology and formation of nasal polyps. To confirm this, further research needs to be undertaken.

Nasal biomarker profiles in acute and chronic rhinosinusitis

BACKGROUND

Clinical manifestations of rhinosinusitis include acute rhinosinusitis, chronic rhinosinusitis (CRS) with nasal polyps and CRS without polyps.

OBJECTIVE

Possible mechanisms defining these three forms of rhinosinusitis should be investigated assessing biomarker profiles in nasal secretions.

METHODS

Fifteen cytokines, three cellular activation markers and total IgE were determined in nasal secretions of seven patients with acute rhinosinusitis, 12 patients with CRS without polyps, 13 patients with CRS with polyps and six healthy controls. Principal component analysis was used to extract relevant factors.

RESULTS

Irrespective of the clinical manifestation, all biomarkers assessed were increased in patients with rhinosinusitis when compared with controls (P<0.001). Principal component analysis allowed the extraction of three factors explaining 83% of data variance. The general inflammatory activation was mainly reflected by the first factor. The second factor differentiated acute from CRS. This factor correlated with IL-12, which is involved in pathogen-related immune activation by antigen-presenting cells. It was also positively correlated with IL-4, IL-10 and IL-13, which play an important role in the resolution of infections. The third factor differentiated CRS with polyps from CRS without polyps (P=0.001). It represented IL-5 and nasal IgE (nIgE), whereas eosinophil cationic protein and tryptase were not specific for CRS with polyps.

CONCLUSION

In mucosal infection, numerous inflammatory mediators are activated. Simple correlations of few biomarkers with a specific disease process bear the risk of overestimating a possibly unspecific effect. To assess biomarker profiles, more complex analytic tools may be more appropriate to delineate mechanisms underlying mucosal disease. Using principal component analysis, it was found that high nIgE and IL-5 levels are specific for CRS with nasal polyps.

Airway inflammation in nasal polyposis: immunopathological aspects of relation to asthma

BACKGROUND

Nasal polyposis (NP) is a chronic inflammatory disorder of the upper respiratory tract, which is often coexist with asthma. However, the pathogenesis of especially in patients with NP is still a matter of debate.

OBJECTIVE

To better understand the immunopathologic mechanism involved in this relationship, we investigated the inflammatory cell profiles in bronchial and nasal tissues of patients with NP alone and with concomitant asthma.

METHODS

Seventeen patients with NP (six male, 11 female, age range: 19-63, mean age: 38.29+/-13.27 years) were selected for the study. Subjects were divided into two groups based on the presence of asthma or bronchial hyper-responsiveness (BHR). NP without BHR (Group 1) (n=8), NP and asthma or BHR (Group 2) (n=9). All patients underwent atopy evaluation including detailed history, skin prick test (SPT), total and specific IgE determination in sera. None of the subjects had taken inhaled, nasal or oral corticosteroids for at least 1 month before the study. Respiratory symptoms of asthmatic patients were controlled with only short acting beta(2)-agonist inhaler drugs as needed. NP tissue, nasal and bronchial mucosa biopsies were taken from all patients using fiberoptic endoscopy. CD3, CD8, CD16, CD68, AA1 (mast cell tryptase), human leucocyte antigen-DR (HLA-DR) and eosinophil peroxidase (EPO) expressing cells in specimens were determined by immunohistochemical methods. Positively staining inflammatory cell types were counted. Subepithelial lamina propria and periglandular areas were separately evaluated.

RESULTS

No significant difference was found in polyp tissue, nasal and bronchial CD3(+), CD8(+), CD16(+), CD68(+), AA1(+), HLA-DR(+) and EPO(+) positive cells between groups. There were significantly higher numbers of CD8(+), CD16(+), HLA-DR(+), EPO(+) cells in the polyp tissue and nasal mucosa vs. the bronchial mucosa in all groups (P<0.05). However, CD8(+) cells were significantly increased in the polyp tissue and bronchial mucosa of patients with NP alone when compared with the patients with both asthma and NP (P<0.05). CD3(+), CD68(+) and CD16(+) cell counts were tended to be higher within the nasal polyp tissue of patients with isolated NP compared with counts within nasal and bronchial mucosa of patients with NP and asthma. Also, patients with isolated NP showed more HLA-DR(+) cells in the nasal polyp tissue and nasal mucosa than those of patients with NP and asthma. Immunoreactivity for EPO(+) eosinophils within the nasal and bronchial mucosa was more prominent in patients with NP and asthma compared with patients with NP alone. The number of EPO(+) eosinophils within the polyp tissue, nasal and bronchial mucosa was higher in the skin prick test negative (SPT -ve) group than the SPT positive (SPT +ve) ones.

CONCLUSIONS

Our results demonstrate that infiltration of inflammatory cells in the nasal and the lower airways do not remarkably differ between patients with NP alone who has no evidence of BHR and asthmatic patients with NP. However, patients with SPT-ve NP reveal more intense eosinophilic inflammation in the entire respiratory mucosa.

Tissue-specific immunoglobulin E in human nasal polyps

Allergy is generally believed to be an underlying cause of nasal polyps. The objective of this study was to define allergic nasal polyps. We investigated specific immunoglobulin E (sIgE) in polyp tissue. Thirty pieces of polyp tissue were taken from patients with positive allergic symptoms, and 30 from patients without allergic symptoms. Nasal polyp tissue homogenate and serum from these patients were prepared for detecting sIgE by a CAP method. For patients with allergic symptoms and/or positive serum CAP test results, the rates of positive tissue CAP tests were low: 36.7% and 35.7%, respectively. However, nearly all of the tissue CAP-positive subjects had allergic symptoms and positive serum CAP tests. We conclude that the local tissue sIgE profile reflects more specifically the allergic status of patients with nasal polyps than does the systemic serum test or the presentation of allergic symptoms. Thus, polyp tissue CAP tests might be performed in patients with positive allergic symptoms and positive serum CAP tests to define an allergy-induced polyp precisely. Then, specific antiallergic treatment could be administered to prevent polyp recurrence.

[Study on the association among total immunoglobulin E and eosinophil in nasal polyp]

OBJECTIVE

To explore the expression of total immunoglobulin E(IgE) and eosinophil in nasal polyp and their roles in the pathogenesis of nasal polyp.

METHOD

Thirty eight patients with nasal polyp and 15 control cases were chosen. All samples were stained with Chromotrope 2R histochemical and SP immunohistochemical method separately to examine eosinophil and total IgE+ cells in nasal polyp.

RESULT

(1) The level of total IgE and eosinophil in nasal polyp was all significantly higher than that in normal control specimens (P < 0.01). (2) The positive correlation of total IgE and eosinophil was significant (r = 0.843, P < 0.01).

CONCLUSION

Nasal polyp is a disease characterized by eosinophils infiltration. Type I allergic reaction mediated by IgE assemble and activate eosinophils which may play an important role in the infiltration pathogenesis of nasal polyp.

Inflammatory mediators and eosinophilia in atopic and non-atopic patients with nasal polyposis

Nasal polyps are characterized by eosinophilic infiltration and presence of inflammatory mediators, such as total IgE, eosinophil cationic protein (ECP) and cytokines. The role of atopy in nasal polyp pathogenesis is still unclear. Therefore, we evaluated serum IgE levels, nasal mucus concentrations of ECP and cytokines and the number of infiltrating eosinophils in nasal tissue of polyps from atopic and non-atopic patients. Samples were obtained from a randomized population of 31 patients with nasal polyposis having endonasal sinus surgery and of 13 control subjects undergone corrective surgery of the nasal septum. On the basis of medical history of allergy, positive skin-prick tests and total IgE levels, patients with polyposis were divided in atopic (n = 13) and non-atopic (n = 18) patients. We determined levels of IgE in blood, ECP and cytokines (IL-4, IL-6, IL-8, IFN-gamma and IL-2) in nasal mucus, and number of infiltrating eosinophils in nasal tissue. The concentrations of total IgE, ECP, IL-4 and IL-8 and eosinophilia were significantly higher in all patients with nasal polyps compared with controls. Inside, all patients with nasal polyposis showed lower levels of IL-6, IFN-gamma and IL-2 compared with controls. The atopic patients showed significant differences when compared with non-atopic patients for the higher concentrations of total IgE (698.80+/-322.24 vs. 279.63+/-234.11; P < 0.0001) and IL-8 (1437.2 pg/ml+/-1250.7 vs. 605.5 pg/ml+/-481.1; P < 0.015). These findings suggest that inflammation still remains the major factor in the etiology of nasal polyposis and show different levels of inflammatory mediators into atopic and non-atopic patients.

Staphylococcal exotoxins and nasal polyposis: analysis of systemic and local responses

BACKGROUND

Staphylococcal exotoxins have been implicated in the pathogenesis of several chronic inflammatory diseases including atopic dermatitis (AD), asthma, and, most recently, chronic rhinosinusitis with nasal polyposis (CRS/NP). In severe AD, these toxins act both as superantigens (SAg), triggering massive T-cell activation, and as conventional allergens, triggering toxin-specific immunoglobulin E (IgE) in the serum. In CRS/NP, evidence for both processes has been reported but it is unclear whether these processes are linked. The aim of this study was to correlate SAg activity as inferred by staphylococcal-specific T-cell receptor (TCR) V-beta expansion in the polyp and blood of CRS/NP patients with staphylococcal-specific anti-IgE antibodies in the serum.

METHODS

IgE antibodies to staphylococcal exotoxin A (SEA), staphylococcal exotoxin B (SEB), and toxic shock syndrome toxin (TSST) 1 were measured in the serum of 12 individuals with CRS/NP before functional endoscopic sinus surgery. Flow cytometry was used to analyze the SEA, SEB, and TSST-1-specific TCR V-beta domains on the T cells from the polyp and blood of these patients.

RESULTS

Serum SEA-, SEB-, and TSST-1-specific IgE antibodies were detected in 0/12 (0%), 6/12 (50.0%), and 9/12 (75%) of CRS/NP patients, respectively. Evidence of SAg effect in the polyp lymphocytes (TCR V-beta expansion in both CD4+ and CD8+ subsets) was noted in 7/12 (58.3%) patients. Five of 6 CRS/NP patients had overlapping evidence of a systemic IgE response and TCR V-beta expansion, suggestive of exposure to the same exotoxin. No patients had evidence a SAg effect in blood lymphocytes. Nine of 12 subjects also had coexistent asthma.

CONCLUSION

These results provide evidence for a local SAg effect in 7/12 (58.3%) polyp patients and establish a positive correlation of V-beta expansion with the presence of corresponding toxin-specific IgE in the serum.

Pathophysiological effects of glucocorticoids on nasal polyps: an update

PURPOSE OF REVIEW

The exact mechanisms by which glucocorticoids exert their beneficial effects on nasal polyps are not clearly defined. Nasal polyps, asthma and allergic rhinitis share common features such as mucosal infiltration with eosinophils and mast cells as well as local IgE production. The present review is an update on the pathophysiological mechanisms of glucocorticoids on nasal polyps described during the last 2 years.

RECENT FINDINGS

The reduction of leukocyte numbers in nasal polyps following glucocorticoid treatment depends on several mechanisms, for example altered balance between the two isoforms of the human glucocorticoid receptors, GRalpha and GRbeta. Another explanation may be inhibition of CD4+ T by CD8+ T cells. Increased expression of the antiinflammatory cytokine transforming growth factor beta may contribute to this. A DNA microarray study which examined the expression of some 22 000 genes showed increased expression of several antiinflammatory genes in nasal polyps after treatment with glucocorticoids. The antiinflammatory gene that increased most was uteroglobin (also known as Clara cell protein 16) which is abundantly expressed in airway secretions and thought to have an important role in regulating inflammation.

SUMMARY

Glucocorticoids affect both pro and antiinflammatory pathways in nasal polyps. Upregulation of antiinflammatory genes such as transforming growth factor beta and uteroglobin may play an important role. Elucidation of these mechanisms may help us to understand not only the effects of glucocorticoids on nasal polyps, but also on related disorders such as allergic rhinitis and asthma.

Expression of interleukins in patients with nasal polyposis

OBJECTIVE

To correlate the levels of interleukins 1beta, 3, 4, and 5 before and after surgery and compare the levels between patients with and without recurrence of nasal polyposis.

STUDY DESIGN AND SETTING

Thirty-nine patients with NP were selected, 13 of them allergic and 26 nonallergic. A control group of 11 individuals was also studied. The concentrations of interleukins were measured by enzyme-linked immunosorbent assay.

RESULTS

There was a higher incidence of NP after the fourth decade of life and among men. The clinical symptoms were similar in both groups of patients with nasal polyposis and characterized by nasal obstruction and anosmia. A significant reduction of all interleukins studied was observed after surgical treatment.

CONCLUSION

Levels of interleukins 1beta, 3, 4, and 5 were significantly reduced after surgery and the levels of interleukins 1beta and 5 were significantly lower in patients without recurrence of nasal polyposis after surgery when compared to those with recurrence.

Nasal polyps in patients with and without cystic fibrosis: a differentiation by innate markers and inflammatory mediators

BACKGROUND

The dysfunction of the mucosal interface of the upper respiratory tract in cystic fibrosis (CF) patients is clinically visible by the development of nasal polyps (NP) at a young age. Innate defence markers and inflammatory mediators in NP from patients with CF were compared with non-cystic fibrosis nasal polyps (non-CF-NP) to determine a possible different immunological background in macroscopically similar tissue.

METHODS

Surgical samples were obtained from patients with non-CF-NP, cystic fibrosis patients with nasal polyps (CF-NP) and control patients (CO). With real time PCR, the mRNA expression of human beta defensins (HBD) 2 and 3, toll-like receptors (TLR) 2 and 4 and the macrophage mannose receptor (MMR) were measured. On homogenates of the surgical samples eotaxin, myeloperoxidase (MPO), IL-5 and IL-8 protein content was measured using commercial ELISA kits; IgE and eosinophilic cationic protein (ECP) were measured by the Unicap system.

RESULTS

In CF-NP we found a statistically significant higher mRNA expression of HBD 2 compared with non-CF-NP and CO and of TLR 2 compared with non-CF-NP. In the non-CF-NP group, MMR mRNA expression was significantly elevated compared with CO and CF-NP. For TLR 4 mRNA expression no statistically significant differences were found between groups. IL-5 was below detection level in all CO and CF-NP, but was measurable in 80% of the non-CF-NP. MPO and IL-8 concentrations were significantly higher in CF-NP compared with CO and non-CF-NP, whereas ECP, eotaxin and IgE were significantly higher in the non-CF-NP group.

CONCLUSIONS

We here demonstrate that CF-NP and non-CF-NP not only differ in terms of inflammatory mediator profile, but also in terms of innate markers.

[Relationship between allergic factors and chronic sinusitis with or without nasal polyps]

OBJECTIVE

To explore the effects of allergic factors in chronic sinusitis and nasal polyps.

METHOD

Eosinophil in nasal secretions and allergen skin test of 1882 patients with chronic sinusitis and nasal polyps were examined before endoscopic sinus surgery. The occurrence ratios of allergic symptoms and syndromes were analyzed and compared with clinical stages of chronic sinusitis and nasal polyps.

RESULTS

(1) Allergic symptoms (or syndromes) were presented in 60.4% (1137 cases) of patients in different degrees, 25.3% (477 cases) patients suffered from allergic rhinitis, 2.1% (39 cases) patients had asthma; (2) The morbidities of allergic rhinitis and asthma, the positive rates of eosinophil and allergen skin test, the occurrence rates of allergic symptoms were rising with the clinical stages in type I and type II, especially in type II stage 3; (3) There were 42.2% (795 cases) positive patients in allergen skin test, among them, 94% were sensitive to perennial allergens; (4) Allergic symptoms appeared in 26.3% (495 cases) patients, among them, 99.8% attacked perennially; (5) Of all patients, there were 38.9% (732 cases) had been operated cases before, among them 38.3% (280 cases) with allergy rhinitis. In chronic sinusitis with allergy rhinitis patients, 58.7% (477 cases) were suffered from operation.

CONCLUSIONS

Allergic factors,especially perennial allergic rhinitis, are relative to clinical stages of chronic sinusitis and nasal polyps. Allergic rhinitis is an important factors in recurrence.

[Examination expression of CD3 and CD69 in nasal polyps]

OBJECTIVE

To investigate the infiltration of T lymphocytes with CD3 expression as surface marker and the activation of T lymphocytes with CD69 expression as activation marker.

METHODS

Nasal polyp tissue samples and peripheral blood were obtained from 21 patients. The normal inferior turbinate mucosa and peripheral blood were obtained as comparison. Flow cytometry was adopted to detect the expression of CD3 and CD69 of T lymphocytes.

RESULTS

Nasal polyp tissue consisted of abundant T lymphocytes. Activation marker CD69 was expressed in T lymphocytes of nasal polyps (36.96 +/- 2.50)% and peripheral blood (4.66 +/- 0.18)% from the same patient. The expression rates of CD69 after a short-term stimulation (5 h) in response to PDB were (59.88 +/- 2.59)% and (92.76 +/- 0.55)% respectively. While T lymphocytes was rarely detected in normal inferior turbinate and the expression of CD69 was low in peripheral blood from normal human but almost all T lymphocytes were activated after stimulation.

CONCLUSIONS

There were generous of T lymphocytes infiltrating in nasal polyps. The expression of CD69 in T lymphocytes was abnormally high, which indicated that T lymphocytes infiltrating in nasal polyps were in activated state immunologically.

Aeroallergen hypersensitivity: comparing patients with nasal polyps to those with allergic rhinitis

Immunoglobulin E-mediated allergy generally has not been considered to be important in the pathogenesis of nasal polyps, despite elevated immunoglobulin E in polyp exudates, tissue eosinophilia, and degranulated mast cells. In previous reports, patients with nasal polyps were more likely to have positive skin tests to perennial than to seasonal allergens. It is postulated that nasal polyps result from the constant nature of perennial allergen exposure. The objective of this report is to compare the prevalence of sensitization to six aeroallergens in a group of nasal polyp (NP) patients, a group of allergic rhinitis (AR) patients, and those subjects with positive skin tests in the National Health and Nutrition Examination Survey (NHANES) II. Twenty-five consecutive NP patients evaluated over a 3-month period of time at Northwestern Allergy and Immunology Outpatient Center, in addition to 50 of the allergic rhinitis patients evaluated over the same time, were chosen randomly. All were skin tested with the following antigens: dog, cat, dust mite, grass, tree, and ragweed. Published skin test data from the NHANES II study of 14,367 individuals was obtained also. The percent of NP patients, AR patients, and NHANES II subjects with sensitization to perennial allergens was 72, 96, and 7.6%, respectively. The difference between the AR and NP patients was statistically significant (p = 0.006). The percent of NP, AR, and NHANES II subjects sensitized to seasonal allergens was 84, 86, and 17.7%, respectively. No statistical significance existed between the AR and NP patients, regarding seasonal allergens. Although the AR and NP had similar levels of reactivity to perennial and seasonal allergens, the NHANES II group was more than twice as likely to be sensitized to a seasonal allergen. The NP and AR groups were similar in prevalence of reactivity to seasonal allergens, but the NP patients in our population actually were less likely to be sensitized to perennial allergens than individuals with AR.

Clinical trial design, nasal allergen challenge models, and considerations of relevance to pediatrics, nasal polyposis, and different classes of medication

Clinical trials in allergic rhinitis present several specific difficulties. In seasonal pollen-related disease, there are variations between subjects in the extent of pollen sensitization, individual variations in exposure to pollen even within a set area because of lifestyle differences, and variations between different areas in pollen counts and weather patterns. Thus, large patient numbers are needed in multicenter trials to account for such variations when the standard endpoint is symptom reporting. Furthermore, a pollen season may be relatively short (eg, lasting 6-8 weeks), and the pollen count is inconsistent during this period. Crossover study designs are thus inappropriate, and trials are usually conducted with a parallel-group design. This further increases the trial sample size as it reduces statistical power. These large patient numbers must be recruited over a very short period. Perennial house dust mite-sensitive allergic rhinitis presents other problems. Although there is less disease variation, it is appreciated that symptoms may be induced by nonallergic as well as allergic mechanisms because of the nasal hyperresponsiveness. The nonallergic symptoms may not be modified by treatments based on allergic disease mechanisms. Thus, symptom outcomes--although relevant to the patient--may not adequately reflect the pharmacologic efficacy of the specific intervention. To control variability and focus on allergic disease mechanisms, nasal allergen challenge has been used in drug development. Single-dose challenges in the laboratory or in a pollen chamber, which allow many volunteers to be studied at the same time, have proven useful in the evaluation of drugs that afford acute symptom relief. However, such challenges incompletely model naturally occurring disease, in which the repeated daily exposure to allergen modifies the mucosal inflammatory cell profile and in particular promotes the epithelial accumulation of effector cells. This alters the response to allergen exposure. To model this, repeated low-dose daily allergen exposure has been used to generate these mucosal changes artificially, and early studies suggest that this may be a more valid model for the evaluation of anti-inflammatory therapy. However, little has been published with this model. Different disease groups are associated with their own specific issues in clinical trials. The pediatric population, in which allergic rhinitis is common, has different requirements for education, quality of life evaluation, and adverse-event monitoring; nasal polyposis, because of the nature of the disease, requires additional means of assessment, such as nasal endoscopy and imaging (eg, computerized tomography scanning), as well as attention to additional outcome measures (eg, the measurement of sense of smell). Within clinical trial design, there are important questions to be considered in relationship to the therapeutic intervention. Should this be given topically or systemically? What are the appropriate timing and frequency of medication? Does the disease itself modify the treatment efficacy, and does combination therapy afford better clinical outcome than single-modality therapy? These issues are discussed, and the influences of current therapies on objective outcome measures in allergic rhinitis are reviewed.

Molecular and cellular staging for the severity of chronic rhinosinusitis

OBJECTIVES

To correlate objective and subjective clinical parameters with molecular, cellular, and histologic markers and to acknowledge the importance of these basic science parameters in a severity classification system for chronic rhinosinusitis (CRS).

STUDY DESIGN

Retrospective analysis of prospectively collected data of consecutive patients undergoing endoscopic sinus surgery for CRS in an academic institution.

METHODS

The preoperative computed tomography (CT) scans of all patients with CRS scheduled for surgery were graded according to Lund and Mackay. The patients completed a Sino-Nasal Outcome Test (SNOT)-20 questionnaire and had a preoperative nasal endoscopy performed, which was graded by assigning an endoscopy score according to Lanza and Kennedy. Subjects had a medical questionnaire regarding presence of aspirin sensitivity, allergic rhinitis, asthma, and medication usage. Subjects also underwent pulmonary function testing and had skin tests for allergies. At the time of surgery, blood was drawn to determine the level of peripheral eosinophilia and the degree of polymorphisms of the leukotriene C4 synthase gene. Sinus mucosal and polyp tissue was examined pathologically for the number of eosinophils per high-powered filed (HPF) and was stained for EG2 to determine the portion of activated eosinophils. Leukotriene C4 levels (pg/g of tissue) were determined using a sensitive competitive enzyme immunoassay. Endoscopy and SNOT-20 scores were reevaluated 1 year after surgery. Data were analyzed for disease-severity correlation to recommend a severity classification system for CRS that incorporates the contribution of clinical, molecular, cellular, and histologic parameters.

RESULTS

The presence of polyps resulted in higher preoperative CT scores and higher preoperative and postoperative symptom scores. Average preoperative CT scores were significantly higher in asthmatics and allergy patients and correlated with endoscopy scores. Patients with more than five eosinophils/HPF of sinus tissue had higher frequency of polyps and asthma and higher CT and endoscopy scores than patients without sinus tissue eosinophilia (less than or equal to 5 cells/HPF sinus tissue). The subgroup of patients with eosinophilic nasal polyps (eosinophilic hyperplastic rhinosinusitis) had more severe disease by CT and endoscopy than the subgroup of patients with nasal polyps (hyperplastic rhinosinusitis) but without eosinophilia. Similarly, patients without polyps but with tissue eosinophilia had more severe disease than patients without polyps and without eosinophilia. Leukotriene C4 levels were elevated in all patient groups. Symptom scores did not correlate with any of the parameters.

CONCLUSION

We suggest the following severity classification system for CRS: 1) eosinophilic chronic hyperplastic rhinosinusitis (ECHRS): patients with polyps and sinus tissue eosinophilia; 2) noneosinophilic chronic hyperplastic rhinosinusitis (NECHRS): patients with polyps but without sinus tissue eosinophilia; 3) eosinophilic chronic rhinosinusitis (ECRS): patients without polyps but with sinus tissue eosinophilia; 4) noneosinophilic chronic rhinosinusitis (NECRS): patients without polyps and without sinus tissue eosinophilia.

Superantigen hypothesis for the early development of chronic hyperplastic sinusitis with massive nasal polyposis

PURPOSE OF REVIEW

The pathogenesis, pathophysiology, and immunobiology of chronic hyperplastic sinusitis with massive nasal polyposis are starting to become unraveled. Allergy, viral infection, bacterial infection, fungal infection, and environmental pollution have all been suggested as possible initial triggers that may upregulate inflammation of the lateral wall of the nose to develop nasal polyposis. The purpose of this review is to present data from our laboratory that suggest that one of the possible early events in the development of inflammation of the lateral wall of the nose in chronic hyperplastic sinusitis with massive nasal polyposis is the production of exotoxins from Staphylococcus aureus. The exotoxins may act as superantigens and cause activation and clonal expansion of lymphocytes with specific Vbeta regions, resulting in massive cytokine production.

RECENT FINDINGS

Recent published studies suggest that S. aureus is the most common organism isolated from the mucus adjacent to massive nasal polyposis. Staphylococci produce exotoxins. These exotoxins, sometimes known as enterotoxins, include SEA, SEB, and TSST-1. These exotoxins are capable of acting as superantigens and therefore, reacting with T lymphocytes with specific Vbetas in the lateral wall of the nose. Thereafter, it is possible that these lymphocytes are stimulated to produce both TH1 and TH2 cytokines, which have also been demonstrated in the nasal polyp. The consequence of these findings may be the upregulation and increased survival of eosinophils in the nasal polyp.

SUMMARY

Staphylococcus aureus is present in the mucin adjacent to nasal polyps in about 60 to 70% of cases of massive nasal polyposis. These organism, as studied up to the present, always produce exotoxins, which may act as superantigens, causing activation and clonal expansion of lymphocytes with specific Vbeta region in the lateral wall of the nose. The present review suggests that activation of these lymphocytes produce both TH1 and TH2 cytokines. The potential damage to the nasal mucosa from eosinophils is briefly discussed. Theoretically, topical antibiotics to suppress the colonization of S. aureus may be a logical approach to downregulate the production of superantigen in the lateral wall of the nose after appropriate endoscopic sinus surgery.

Protein nitration in chronic sinusitis and nasal polyposis: role of eosinophils

OBJECTIVES

To investigate the possible role of eosinophil peroxidase (EPO) in 3-nitrotyrosine (3NT) formation.

STUDY DESIGN AND SETTING

Observational study employing immunocytochemistry to assess the presence of 3NT, inducible nitric oxide synthase (iNOS), eosinophils, mast cells, neutrophils, and lymphocytes in ethmoid sinus mucosal biopsies from normal controls and subjects with allergic and nonallergic chronic sinusitis and nasal polyposis.

RESULTS

3NT was more evident in biopsies from sinusitis patients (2.67 +/- 0.14, n = 21) than in healthy mucosa (0.43 +/- 0.2, n = 7, P < 0.01), but scores in atopic and nonatopic subjects were similar. Colocalization studies confirmed that 3NT was largely confined to eosinophils. No relationship was found between 3NT and other immune cells. 3NT detection was not correlated with the amount of immunostaining for iNOS.

SIGNIFICANCE

Chronic sinusitis is accompanied by 3NT formation, which is largely restricted to the eosinophils, and likely driven by the action of eosinophil peroxidase, rather than by nitric oxide levels.

EBM RATING

B-2.

Alterations in eotaxin, monocyte chemoattractant protein-4, interleukin-5, and interleukin-13 after systemic steroid treatment for nasal polyps

OBJECTIVE

To determine alterations in Th2 chemokines eotaxin and monocyte chemoattractant protein-4 (MCP-4), and cytokines interleukin-5 (IL-5) and interleukin-13 (IL-13), in nasal polyps (NP) after steroid treatment.

STUDY DESIGN

Cytokine/chemokine levels were measured in NP before and after steroid therapy and compared to control sinus mucosa.

RESULTS

Twenty-one patients (control = 7, NP = 14) were enrolled. Eotaxin and MCP-4 were significantly higher than control tissue (P = 0.004 and 0.003). All four mediators decreased after steroid treatment (P < 0.03). IL-5 and IL-13 in untreated polyps were not significantly different from controls. Patients showed clinical improvement according to SNOT-20 scores (average presteroid score 19, poststeroid score 13) and endoscopic grading (1.75 each side presteroid, 1.13 poststeroid).

CONCLUSIONS

Steroids significantly decreased all cytokine/chemokine levels, but the impact on Th2 chemokines was of a much greater magnitude.

SIGNIFICANCE

Novel approaches to block inflammatory mediators, particularly Th2 chemokines, may lead to better control of nasal polyposis in the future.