Dynamics of COX-2 in nasal mucosa and nasal polyps from aspirin-tolerant and aspirin-intolerant patients with asthma

BACKGROUND: Only dynamic studies can elucidate the discrepancies concerning the expression of the inducible COX-2 gene in inflammatory airway diseases. OBJECTIVES: To quantify the expression and spontaneous regulation of COX-1 and COX-2 mRNAs in nasal polyps and nasal mucosa by real-time PCR. METHODS: Nasal polyps were obtained from 16 aspirin-tolerant patients with asthma/rhinitis (ATAR) and 18 aspirin-intolerant patients with asthma/rhinitis (AIAR) undergoing nasal polypectomy. Nasal mucosa was obtained from 12 subjects undergoing nasal corrective surgery. All specimens were cut into 3 pieces. One was immediately snap-frozen in liquid nitrogen, and the remaining 2 were left at room temperature for 30 or 60 minutes before freezing. Data are presented as medians and 25th to 75th percentiles of 10 6 cDNA molecules/microg total RNA. RESULTS: Baseline COX-2 mRNA levels were significantly lower in both ATAR (0.45; 0.13-1.20; P <.05) and AIAR (0.24; 0.12-0.41; P <.001) nasal polyps than in nasal mucosa (1.35; 0.52-3.90). COX-2 mRNA expression did not change over time in nasal mucosa but increased significantly in ATAR nasal polyps ( P <.05), reaching similar levels to nasal mucosa after 60 minutes. In contrast, COX-2 mRNA showed no significant change over time in AIAR nasal polyps. COX-1 mRNA was higher in nasal polyps than in nasal mucosa, and its expression was not modified over time in any group of patients. CONCLUSION: These results suggest differential kinetics of COX-2 mRNA between nasal mucosa and nasal polyps. AIAR nasal polyps appear to have a greater abnormality of the COX-2 pathway than ATAR.     

Aspirin-intolerant asthma: role of cyclo-oxygenase enzymes

Aspirin-induced asthma and rhinitis (AIAR) appear to be precipitated by the inhibition of cyclo-oxygenase (COX). By inhibiting COX pathway aspirin diverts arachidonic acid metabolites to the lipoxygenase pathway. There are two isoforms of COX, namely COX-1 and COX-2. Metabolites derived from COX-1 are involved in cellular housekeeping functions. COX-2 can be induced in cells exposed to proinflammatory substances and growth factors. Recent studies have reported that patients with AIAR have decreased activity of COX-2 and lower production of PGE₂ in the upper airway and peripheral blood cells. Considering the protective effect of exogenous PGE₂ on aspirin-induced bronchoconstriction and the interdependence of PGE₂ and cisteinyl leukotriene production, a reduced PGE₂ synthesis may render aspirin-sensitive patients more susceptible to the inhibitory effect of NSAIDs drugs and also lead to an increase in cysteinyl leukotriene release.     

Adhesion molecules and their ligands in nasal polyps of aspirin-hypersensitive patients.

BACKGROUND: Chronic inflammation with tissue eosinophilia plays a key role in the pathogenesis of asthma and nasal polyps in patients with aspirin hypersensitivity. OBJECTIVE: To evaluate the expression of vascular cell adhesion molecule 1 (VCAM-1) and intercellular adhesion molecule I (ICAM-1) and their ligands (the integrins lymphocyte function-associated antigen 1 and very late-activation antigen 4 [VLA-4]) in nasal polyps of patients with aspirin hypersensitivity compared with aspirin-tolerant individuals. METHODS: Immunohistochemical studies were performed using a peroxidase method and monoclonal antibodies on 6-microm-thick cryostat sections cut from frozen polyps collected during elective surgery from 21 aspirin-sensitive and 23 aspirin-tolerant patients. RESULTS: The mean +/- SD values of the semiquantitatively evaluated immunoexpression of ICAM-1, VCAM-1, and VLA-4 were significantly increased in patients with aspirin hypersensitivity compared with aspirin-tolerant patients (1.7 +/- 0.8 vs 0.9 +/- 0.8, P < .003; 1.8 +/- 0.8 vs 0.8 +/- 0.8, P < .001; and 2.2 +/- 0.7 vs 1.3 +/- 0.7, P < .001, respectively), whereas the mean +/- SD values of the expression of lymphocyte function-associated antigen 1 did not differ significantly (2.4 +/- 0.5 vs 2.2 +/- 0.9; P = .57). We found a correlation between the immunoexpression of VCAM-1 and its ligand VLA-4 in all studied tissue samples (r = 0.4; P < .02). CONCLUSIONS: In nasal polyps of aspirin-hypersensitive patients, up-regulation of the adhesion molecules ICAM-1 and VCAM-1 and the integrin VLA-4 may play an important role in the development of chronic eosinophilic inflammation.     

The increased number of epithelial mast cells in nasal polyps and adjacent turbinates is not allergy-dependent

Respiratory epithelial mast cells are an expression of airway inflammatory processes. Nasal epithelial mast cells are known to be increased in allergic rhinitis and have now been examined in patients with nasal polyps. Metachromatic cell counts (mean +/- standard error) expressed as the sum of large mast cells, atypical mast cells and basophils in epithelial scrapings of the inferior turbinates, assessed after Carnoy's fixation and toluidine blue staining (pH 0.5), were 37.5 +/- 29 in non-allergic normal control subjects (n = 11), 435 +/- 130 in polyp patients who were allergic (n = 18), and 699 +/- 267 in polyp patients who were not allergic (n = 8). Metachromatic cell counts in epithelial scrapings obtained in vivo from nasal polyps of allergic patients (n = 8) were 1769 +/- 962, and 2308 +/- 1544 from polyps of non-allergic patients (n = 5); metachromatic counts were 2089 +/- 633 in epithelial scrapings from excised polyps of allergic patients (n = 14) and 2214 +/- 640 from polyps of non-allergic patients (n = 13). It is concluded that the number of metachromatic cells in the epithelium of nasal polyps and the adjacent nasal mucosa is elevated compared with normal nasal epithelium and the increased number does not depend upon allergy.     

Safety of meloxicam in aspirin-hypersensitive patients with asthma and/or nasal polyps. A challenge-proven study

BACKGROUND: The anti-inflammatory actions of acetylsalicylic acid (ASA)/non-steroidal anti-inflammatory drugs (NSAIDs) are thought to be due to inhibition of COX-2, whereas the side effects such as gastric damage and aspirin-induced asthma are mediated through inhibition of COX-1. Therefore, a new class of drugs with COX-2 selectivity may be well tolerated by patients with ASA/NSAIDs hypersensitivity. OBJECTIVE: We investigated whether subjects with asthma and/or nasal polyps (NP) and analgesic intolerance proven by oral ASA provocation test tolerated the selective COX-2 inhibitor, meloxicam. METHODS: All subjects were first challenged with ASA using a 2-day, single-blind, placebo-controlled oral provocation test. Thereafter, the subjects showing positive response to ASA provocation underwent a single-blind, placebo-controlled challenge with a cumulative dose of 7.5 mg of meloxicam on 2 separate days. One and three fourths of the divided doses of placebo and the active drug were given at 1-hour intervals. Clinical symptoms, lung function, and blood pressure were monitored during these challenge protocols. RESULTS: Twenty-one patients with asthma and/or NP (10 males and 11 females; mean age: 38.4 +/- 2.9 years) who reacted to ASA challenges were enrolled in the study. Response to ASA provocation was rhinitis + bronchospasm in 13, and extrabronchial reactions in 8 (isolated rhinitis in 3) patients. Mean PD(20) was 163.4 +/- 39.9 mg ASA among patients who reacted with bronchospasm to ASA. Only 1 patient reacted to meloxicam challenge at a cumulative dose of 7.5 mg. CONCLUSION: This study indicates that 7.5 mg of meloxicam is a safe alternative treatment for ASA-hypersensitive asthma and/or NP patients with proven hypersensitivity via oral ASA challenges.     

Aspirin-sensitive rhinosinusitis is associated with reduced E-prostanoid 2 receptor expression on nasal mucosal inflammatory cells

BACKGROUND: Impaired braking of inflammatory cell cysteinyl leukotriene production by prostaglandin (PG) E(2) has been implicated in the pathogenesis of aspirin exacerbated airways disease, but the mechanism is obscure. PGE(2) acts via G-protein-coupled receptors, E-prostanoid (EP)(1-4,) but there is little information on the expression of PGE(2) receptors in this condition. OBJECTIVE: To address the hypothesis that expression of 1 or more EP receptors on nasal mucosal inflammatory cells is deficient in patients with aspirin-sensitive compared with nonaspirin-sensitive polypoid rhinosinusitis. METHODS: By using specific antibodies, immunohistochemistry, and image analysis, we measured the expression of EP(1-4) in nasal biopsies from patients with aspirin-sensitive (n = 12) and nonaspirin-sensitive (n = 10) polypoid rhinosinusitis and normal controls (n = 9). Double-staining was used to phenotype inflammatory leukocytes expressing EP(1-4). RESULTS: Global mucosal expression of EP(1) and EP(2), but not EP(3) or EP(4), immunoreactivity was significantly elevated in aspirin-sensitive and nonaspirin-sensitive rhinosinusitis compared with controls (P < .03). This was attributable principally to elevated expression on tubulin(+) epithelial cells and Mucin 5 subtypes A and B (Muc-5AC(+)) goblet cells. In contrast, the percentages of neutrophils, mast cells, eosinophils, and T cells expressing EP(2), but not EP(1), EP(3), or EP(4), were significantly reduced (P < or = .04) in the aspirin-sensitive compared with nonaspirin-sensitive patients. CONCLUSION: The data suggest a possible role for PGE(2) in mediating epithelial repair in rhinitis and asthma. Because PGE(2) exerts a range of inhibitory actions on inflammatory leukocytes via the EP(2) receptor, its reduced expression in aspirin-sensitive rhinosinusitis may be partly responsible for the increased inflammatory infiltrate and production of cysteinyl leukotrienes that characterize aspirin-sensitive disease.     

Nasal polyps in asthma and rhinitis: A review of 6,037 patients

Data from records of patients with asthma and rhinitis in the Rhode Island Hospital Adult Allergy Clinic and in an adult allergy private practice were reviewed. The frequency of nasal polyps in the total population of 4,986 was 4.2%; in the asthmatic portion of the population the frequency was 6.7%, and in the rhinitis alone group the frequency was 2.2%. Asthmatics with negative allergy skin tests to inhalant allergers had significantly more nasal polyps than asthmatics with positive skin tests, 12.5% vs 5.0%, p < 0.01. The frequency of nasal polyps increased with advancing years. Of the total 211 cases of nasal polyps, 71% had asthma and 29% had rhinitis alone. Also, 14% of the patients with nasal polyps had aspirin intolerance, primarily of the bronchospastic type. In addition, 1,051 patients with asthma and rhinitis from the Pediatric Allergy Clinic with a mean age of 6 yr were similarly evaluated. Only 1 (0.1%) of these pediatric patients had nasal polyps.     

Aspirin sensitive rhinosinusitis: the clinical syndrome and effects of aspirin administration

Nineteen aspirin sensitive adult patients were identified who experienced naso-ocular responses without associated bronchospasm during standardized oral aspirin challenge. These 19 patients exhibited the characteristics of the aspirin triad except asthma. These included hypertrophic rhinitis with or without associated nasal polyps, abnormal sinus roentgenograms, nasal eosinophilia, aspirin-provoked responses of the upper airway identical to those observed in aspirin-sensitive asthmatics, capacity of the upper airway to be desensitized to aspirin, and cross-reactivity andlor cross-desensitization of the upper airway to indomethacin. Of the 17 patients who were treated with daily aspirin after desensitization, 77% experienced improvement in their nasal symptoms.     

Nasal versus bronchial and nasal response to oral aspirin challenge: Clinical and biochemical differences between patients with aspirin-induced asthma/rhinitis

BACKGROUND: Aspirin-induced asthma/rhinitis (AIAR) is characterized by the altered metabolism of leukotrienes and proinflammatory prostaglandins. The basal and postchallenge levels of eicosanoids might reflect the clinical and biochemical characteristics of patients with distinct types of hypersensitive responses to aspirin. OBJECTIVE: We compared clinical and eicosanoid profiles of patients with AIAR showing both bronchial and nasal versus isolated nasal responses to aspirin challenge. METHODS: Twenty-three patients with AIAR underwent the single-blind, oral, placebo-controlled aspirin challenge. The bronchial response (BR) was evidenced by dyspnea and spirometry, whereas the nasal response (NR) was evidenced by nasal symptoms and acoustic rhinometry and/or rhinomanometry. Urinary leukotriene E4 (uLTE4), serum and urinary stable prostaglandin D2 metabolite, and 9alpha,11beta-prostaglandin F2 (9alpha,11beta-PGF2), were determined at baseline and after the aspirin challenge. RESULTS: Fifteen subjects showed BR and NR (BNR), whereas 8 showed NR only. Basal uLTE4 in the BNR group was significantly higher than in the NR group. After aspirin challenge, it increased significantly in both groups. Serum 9alpha,11beta-PGF2 increased after aspirin challenge in the BNR group only. The patients with BNR had more severe AIAR. CONCLUSIONS: BNR to aspirin in AIAR indicates a more advanced disease and more profound underlying eicosanoid metabolism disturbances.     

Matrix metalloproteinases and their inhibitors in the nasal mucosa of patients with perennial allergic rhinitis.

BACKGROUND: Allergic rhinitis and asthma show many similarities in their epithelial and inflammatory responses to allergens. However, one notable difference is that disruption and desquamation of the epithelium is a characteristic feature of asthma, whereas in perennial allergic rhinitis the epithelium is intact and thickened. One reason for this might be differing expression of matrix metalloproteinases (MMPs) or their inhibitors (TIMPs). There are few published data on the presence of MMPs or TIMPs in the nasal mucosa in rhinitis. OBJECTIVE: The purpose of this study was to investigate MMP and TIMP mRNA and protein in nasal mucosa from subjects with perennial allergic rhinitis and from nonrhinitic control subjects. METHODS: Biopsy specimens of nasal mucosa were taken from 10 well-characterized subjects with perennial allergic rhinitis and 10 nonrhinitic control subjects. MMP and TIMP mRNA was quantified through use of competitive RT-PCR, and protein was detected by means of Western blotting and ELISA. RESULTS: TIMP-1 mRNA and TIMP-2 mRNA were present in nasal samples, but there was no significant difference between the 2 groups. Only small amounts of MMP-1, -2, -3, and -9 mRNA were detected in the same samples. The corresponding proteins were detected by means of Western blotting. TIMP-1 protein and TIMP-2 protein were quantified in tissue homogenates; there was no significant difference between the 2 groups. CONCLUSION: Our studies have demonstrated the presence of large amounts of TIMP-1 and TIMP-2 mRNA and protein in nasal mucosa. There is no upregulation of MMPs or changes in TIMP expression in the nasal mucosa of patients with allergic rhinitis.     

Topical nasal lysine aspirin in aspirin-sensitive and aspirin-tolerant chronic rhinosinusitis with nasal polyposis

Chronic rhinosinusitis patients with nasal polyps can be aspirin sensitive or aspirin tolerant. The majority belong to the latter group. They tolerate intake of aspirin or other non-steroidal anti-inflammatory drugs, whereas aspirin-sensitive patients have an adverse reaction (asthma, rhinitis and/or urticaria). Diagnosis of aspirin sensitivity is important for the patient, but is rarely undertaken in routine ENT or respiratory medicine practice. Treatment of nasal polyps is by a combination of medical therapy and surgery. Oral and topical steroids form the mainstay of medical therapy, which is aimed at reducing inflammation and symptom improvement. Surgery helps with polyps causing severe nasal obstruction. Despite these therapies, recurrences are common in aspirin sensitive patients. Any adjunctive therapy to prevent or prolong recurrence would be welcome. One such possibility is topical nasal lysine-aspirin. This is an area under current debate and this non-systematic review aims to provide evidence of its use, to date, in aspirin sensitive and aspirin tolerant nasal polyp patients.     

Expression of 5-lipoxygenase and cyclooxygenase pathway enzymes in nasal polyps of patients with aspirin-intolerant asthma

In aspirin-intolerant subjects, adverse bronchial and nasal reactions to cyclooxygenase (COX) inhibitors are associated with over-production of cysteinyl-leukotrienes (cys-LTs) generated by the 5-lipoxygenase (5-LO) pathway. In the bronchi of patients with aspirin-intolerant asthma, we previously linked cys-LT over-production and aspirin hyper-reactivity with elevated immunoexpression in eosinophils of the terminal enzyme for cys-LT production, LTC4 synthase. We investigated whether this anomaly also occurs in the nasal airways of these patients. Immunohistochemical expression of 5-LO and COX pathway proteins was quantified in nasal polyps from 12 patients with aspirin-intolerant asthma and 13 with aspirin-tolerant asthma. In the mucosa of polyps from aspirin-intolerant asthmatic patients, cells immunopositive for LTC4 synthase were four-fold more numerous than in aspirin-tolerant asthmatic patients (p=0.04). There were also three-fold more cells expressing 5-LO (p=0.037), with no differences in 5-LO activating protein (FLAP), COX-1 or COX-2. LTC4 synthase-positive cell counts correlated exclusively with mucosal eosinophils (r=0.94, p<0.001, n=25). Co-localisation confirmed that five-fold higher eosinophil counts (p=0.007) accounted for the increased LTC4 synthase expression in polyps from aspirin-intolerant asthmatic patients, with no alterations in mast cells or macrophages. Within the epithelium, increased counts of eosinophils (p=0.006), macrophages (p=0.097), and mast cells (p=0.034) in aspirin-intolerant asthmatic polyps were associated only with 2.5-fold increased 5-LO-positive cells (p<0.05), while the other enzymes were not different. Our results indicate that a marked over-representation of LTC4 synthase in mucosal eosinophils is closely linked to aspirin intolerance in the nasal airway, as in the bronchial airways.     

Nasal mucosal expression of nitric oxide synthases in patients with allergic rhinitis and its relation to asthma.

BACKGROUND: Nitric oxide (NO) has contradictory roles in the pathophysiology of allergic inflammation in both allergic rhinitis (AR) and asthma. Small amounts of NO produced by constitutive NO synthase (NOS) is anti-inflammatory, whereas large amounts produced by inducible NOS (iNOS) are proinflammatory. OBJECTIVE: To investigate the difference in constitutive endothelial NOS (eNOS) and iNOS expression in nonallergic and allergic mucosa and the possible relation of this to the coexistence of asthma in seasonal AR. METHODS: Seventeen patients (10 women and 7 men) with seasonal AR and 9 nonallergic patients (5 women and 4 men) with nasal septum deviation were enrolled. Inferior turbinate nasal biopsy specimens were obtained in all. Levels of eNOS and iNOS expressed as immunohistochemical scores (HSCOREs) were determined immunohistochemically from the specimens. RESULTS: The mean +/- SD HSCOREs for eNOS in patients with seasonal AR were not significantly different from those of the nonallergic controls (1.85 +/- 0.78 vs 1.63 +/- 0.54; P = .12). On the other hand, the mean +/- SD HSCOREs for iNOS were significantly higher in patients with seasonal AR (1.75 +/- 0.75 vs 0.71 +/- 0.6; P = .004). Furthermore, although eNOS expression was not different between seasonal AR patients with and without asthma, the mean +/- SD HSCOREs for iNOS were significantly higher in the patients with asthma (1.93 +/- 0.78 vs 1.65 +/- 0.55; P = .01). CONCLUSION: Increased expression of iNOS might have a role in the development of allergic inflammation in upper and lower airways and in comorbidity of AR and asthma.     

Asymptomatic IgE mediated food hypersensitivity in patients with nasal polyps

The aim of this prospective study is to compare the prevalence of atopy in patients afflicted by nasal polyps with the atopy prevalence in healthy volunteers without nasal polyps, since systemic allergy and allergy in the nasal mucosa are still being debated as underlying causes for nasal polyps. Thirty-four cases with nasal polyposis without asthma and history of allergy or atopic disease were enrolled in the study and compared with 20 healthy volunteer controls in respect to asymptomatic food hypersensitivity. Hypersensitivity for 48 kinds of commonly consumed food in Turkey was investigated by an epicutaneuos prick test, Multi-Test II (Lincoln Diagnostic, Inc, USA), using a special applicator. The food allergy test was positive in 25 out of the 34 cases with nasal polyps and in 6 out of the 20 controls. The difference between the two groups was statistically significant (chi2 = 0.000, p < 0.001). The number of skin tests with positive results in patients with nasal polyps ranged from 1 to 37 (mean +/- S.D. = 10.0 +/- 7.9), whereas in the control subjects the range was 1 to 10 (mean +/- S.D. = 4.0 +/- 3.3). The difference in the number of food reactions was also statistically significant. Asymptomatic food hypersensitivity, being immunologically mediated, may be a triggering factor for the pathogenesis of nasal polyps. Therefore, treatment of asymptomatic food allergy in patients with nasal polyps may alleviate symptoms, slow the progress of nasal polyps and prolong the disease-free interval after polypectomy.     

Differential effects of aspirin and misoprostol on 15-hydroxyeicosatetraenoic acid generation by leukocytes from aspirin-sensitive asthmatic patients

BACKGROUND: Although the mechanisms of aspirin-induced rhinosinusitis-asthma appear to be related to arachidonic acid abnormalities, only recently has a specific aspirin-triggered enhancement of 15-hydroxyeicosatetraenoic acid (15-HETE) generation in nasal polyp epithelial cells from aspirin-sensitive patients been demonstrated. OBJECTIVE: The aim of this study was to assess generation of 15-HETE and other eicosanoids by peripheral blood leukocytes (PBLs) from aspirin-sensitive and aspirin-tolerant asthmatic patients and modulation of 15-HETE generation by a prostaglandin (PG) E(1) analogue (misoprostol). METHODS: Twenty-four aspirin-sensitive patients with asthma-rhinosinusitis and 18 aspirin-tolerant asthmatic patients were studied, and eicosanoids released from PBLs were assessed by means of enzyme immunoassays. RESULTS: Unstimulated PBLs from aspirin-sensitive and aspirin-tolerant patients generated similar amounts of PGE(2), leukotriene C(4), and 15-HETE, but lipoxin A(4) release was significantly less in aspirin-sensitive patients (300 +/- 70 pg/mL) in comparison with that seen in aspirin-tolerant patients (690 +/- 100 pg/mL, P <.05). Cell incubation with 2, 20, or 200 micromol/L aspirin resulted in a dose-dependent increase in 15-HETE generation (mean change of +85%, +189%, and +284% at each aspirin concentration, respectively) only in aspirin-sensitive asthmatic patients. Naproxen stimulated 15-HETE generation in aspirin-sensitive asthmatic patients, but indomethacin or specific COX-2 inhibitors (NS-398 and celecoxib) did not affect 15-HETE release. A synthetic PGE(1) analogue (misoprostol) inhibited aspirin-induced 15-HETE release but enhanced 15-HETE generation by aspirin in leukocytes from aspirin-tolerant patients. After preincubation with misoprostol, aspirin induced a dose-dependent production of lipoxin A(4) in both groups. CONCLUSION: PBLs from patients with aspirin-sensitive rhinosinusitis-asthma might be specifically triggered by aspirin to generate 15-HETE. Metabolism of 15-HETE is differentially regulated by misoprostol in aspirin-tolerant and aspirin-sensitive asthmatic patients.     

Correlation between nasal symptoms and asthma severity in patients with atopic and nonatopic asthma.

BACKGROUND: The association between allergic rhinitis and asthma has been well recognized, and it has been postulated that rhinitis may worsen asthma. OBJECTIVE: To investigate the severity of asthma among patients with atopic and nonatopic asthma with and without nasal symptoms. METHODS: Atopic asthmatic patients and nonatopic asthmatic patients were identified from the records of a university-based asthma clinic. A comparison of demographic clinical features was made within and between these 2 asthmatic groups, dichotomized according to the presence or absence of rhinitis. RESULTS: A total of 178 patients were classified as having atopic asthma and 218 as having nonatopic asthma. The atopic asthmatic patients with nasal symptoms compared with those without had a higher mean forced expiratory volume in 1 second (FEV1), a higher forced vital capacity (FVC), and a higher FEV1/FVC ratio, used fewer oral steroids, and had fewer hospitalizations. The nonatopic asthmatic patients with nasal symptoms compared with those without used more inhaled steroids (and they were also more likely to have nasal polyps on examination). Atopic, relative to nonatopic, asthmatic patients were younger, had a longer duration of asthma, had a higher FEV1/FVC ratio, and took fewer oral steroids. CONCLUSION: Contrary to current hypotheses, in this study the severity of asthma among atopic asthmatic patients was less in those with nasal symptoms. Conversely, among the nonatopic asthmatic patients, asthma was more severe among those with nasal symptoms than those without nasal symptoms.     

Nasal mucosal gene expression in patients with allergic rhinitis with and without nasal polyps

BACKGROUND: Nasal polyps are a common problem that is difficult to diagnose and treat, in part because the cause of nasal polyposis is unknown. Although information on the pathogenesis of polyposis is lacking, there are reports suggesting that a genetic predisposition underlies this disorder. OBJECTIVE: We sought to better understand the basis of nasal polyposis associated with allergic rhinitis. We hypothesize that the expression of unique genes is associated with the nasal polyposis phenotype. METHODS: We examined 12000 human genes transcribed in the nasal mucosa of patients with allergic rhinitis with and without nasal polyps. Biopsy specimens of the mucosa of patients with and without polyps were obtained after the patients refrained from the use of topical or systemic steroid therapy for 2 weeks. RESULTS: Thirty-four genes were differentially expressed between the patient groups, including those for inflammatory molecules and putative growth factors. The greatest differential expression identified by the array analysis was for a group of genes associated with neoplasia, including mammaglobin, a gene transcribed 12-fold higher in patients with polyps compared with control patients with rhinitis alone. Quantitative RT-PCR confirmed this differential expression and documented that the number of mammaglobin mRNA copies is actually 64-fold greater in tissues of patients with polyps versus control patients. The specificity of mammaglobin protein expression was evaluated by means of immunohistochemistry, which showed specific staining in nasal polyp mucosal goblet cells only in patients with polyps. CONCLUSION: These data suggest that nasal polyposis involves deregulated cell growth, using gene activation in some ways similar to a neoplasm. In addition, mammaglobin, a gene of unknown function associated with breast neoplasia, might be related to polyp growth.     

Inhalation and nasal challenge in the diagnosis of aspirin-induced asthma

Inhalation and nasal aspirin challenge has been investigated in asthma patients with co-existing rhinitis. Eight of 39 asthma patients were diagnosed as aspirin-sensitive on the basis of inhalation challenge. Seven aspirin-sensitive asthmatics were subjected to nasal aspirin provocation. During nasal challenge, all seven patients experienced a fall in FEV1 of at least 15%, two showed a significant increase (greater than 400%) in nasal airways resistance (NAR) and one developed urticaria. No significant changes in FEV1 or NAR were observed in nine normal subjects after aspirin inhalation and nasal challenge. There were no significant changes in FEV1 or NAR in six aspirin-tolerant asthmatics when aspirin was given intranasally. The results of this study show that aspirin nasal provocation impairs lung function in aspirin-sensitive asthmatics. In comparison with inhalation challenge responses are generally milder and easier to control. Nasal challenge is also less time-consuming than other methods of aspirin challenge and is therefore more suitable for routine use.