A brush method to harvest cells from the nasal mucosa for microscopic and biochemical analysis

Sample collection for laboratory-based study of the nasal airway and sinuses: a research compendium

BACKGROUND

Collection of biologic samples from the nasal cavity and paranasal sinuses is of critical importance to the study of infectious or inflammatory conditions that affect both upper and lower airways. Numerous techniques for the study of ex-vivo samples exist, with specific applications, strengths, and weaknesses associated with each of them. In this compendium we summarize the available methods for collection of primary human samples and incorporate expert discussion of the pros, cons, and applications associated with each technique.

METHODS

An expert panel containing members of the American Rhinologic Society's Research and Grants Committee compiled this educational reference. Rationale for use and the potential advantages and disadvantages are discussed. Research protocols and key references are enumerated.

RESULTS

Sampling of the nasal cavity and paranasal sinuses can be achieved through a number of methods. Nonspecific sinonasal secretions may be collected via forced exhalation, nasal lavage, and nasal spray aspiration. Targeted collection of sinonasal secretions may be achieved via endoscopic placement of absorbent matrices. Nasal cytology or collection of superficial epithelium may be completed via brushing or scraping of endonasal structures. Collection of mucosal biopsies may be completed via sinonasal explant or full-thickness biopsy.

CONCLUSION

Multiple sampling techniques are available to collect biologic samples from the sinonasal cavity. These techniques differ in their ease of application, reproducibility, sample yield, and utility for different sinonasal pathologies or research goals. An appreciation of the benefits and drawbacks of each approach will allow investigators to select the techniques most appropriate for achieving research objectives.

Cellular Infiltration in Allergic Late-Phase Reaction of the Nose: Immunohistochemical Studies

As with the bronchial system and the skin, the human nose may react with an immediate-phase (IPR) and late-phase reaction (LPR) upon allergen exposure. In this study we challenged intranasally 11 unselected grass-pollen-allergic patients and three normal controls with increasing allergen concentrations to provoke similar IPR symptoms in each person. A nasal symptom score and the bilateral nasal resistance were measured for 8 hours, repeated mucosal surface cell samples were performed (brush technique) before and every 2 hours after the challenge for histological and immunohistochemical investigations on cellular events during the nasal LPR. Apart from neutrophil and eosinophil infiltration, the LPR was accompanied by the migration of metachromatic cells, IgE positive cells, and macrophages/monocyte-like cells. IgE-positive cells could be identified as mast cells/basophils; from the discrepancy between the numbers of IgE- and metachromatic cell types we conclude the degranulation of these mediator cells not only during the IPR, but also during the LPR. The migration of IGE-bearing mediator cells onto the mucosal surface may represent an explanation for the increased reactivity of the organ due to repeated allergen exposure. Furthermore, the migration points to these cells as a means of transport for IgE molecules. The increase in density of macrophages/monocyte-like cells on the nasal mucosal surface during the LPR suggests an important role of these inflammatory cells in antigen processing and/or maintaining of chronic inflammatory reactions.

Cytopathology of the Nasal Mucosa in Smokers: A Possible Biomarker of Air Pollution?

In our search for an easy, reliable, and inexpensive screening method to assess the toxic effects of air pollution and the attendant cancer risk on the respiratory tract, we investigated to what extent brush cytology of the nasal mucosa satisfies these demands. Using brush cytology, we examined the nasal mucosa of 60 cigarette smokers and compared the cytopathologic findings with those of 60 nonsmokers. All subjects were healthy male office workers with no nasal disorders. Mucosal cells were obtained from the maxillo-turbinal region with a small nylon brush, subsequently processed by Papanicolaou staining on a glass slide, and examined “blinded” by cytopathologists. The cytologic findings were normal in 46 of the nonsmokers, with simple squamous cell metaplasia detectable in the remaining 14 of this group. However, in the group of cigarette smokers, 52 showed unequivocal dysplasia of various degrees, whereas merely eight showed only metaplasia. Dividing the smokers into two groups based on pack/years of cigarette consumption revealed that the severity of dysplasia (mild or moderate) correlated well with the pack/years (P = 0.0001). As yet, no significant relation between smoking habits and the incidence of nasal sinus squamous cell carcinomas has been demonstrated in contrast to the established relationship between smoking and carcinomas of the larynx and lungs. Nevertheless, it is conceivable that cytopathologic changes in the nasal mucosa could act as a biomarker reflecting similar changes in the lower respiratory tract.

Future Horizons in Allergy

There are several advances in diagnosis and management for the otolaryngologist treating allergy. These include new technologies and the refinement of current techniques, and reflect overall trends in health care toward personalized medicine. Local immunoglobulin, urinary leukotriene E4, lipidomics, microRNA within extracellular vesicles, and optical rhinometry all offer to improve the diagnostic accuracy of allergy and related nonallergic conditions. New delivery systems for intranasal steroids and antihistamines, recombinant allergens, advances in allergen immunotherapy delivery, and biologics will improve current management options. These developments will aid the otolaryngologist in diagnosing and treating allergy and related diseases.

Thaumatin and gum arabic allergy in chewing gum factory workers

Thaumatin is a sweetener and flavor modifier commonly used in the food industry. Likewise, gum arabic is widely used as a food stabilizer and thickening agent. We report here that a powder mixture composed of 10% thaumatin and 90% gum arabic led to allergic symptoms in the upper airways in occupationally exposed individuals: four of eight workers of a chewing gum factory exposed to this powder mixture had pronounced rhinitis. A positive skin prick test result for pure thaumatin was obtained in all four individuals with rhinitis of whom two also had a positive skin prick test result for pure gum arabic and gum arabic-specific IgE. Subsitution of a powdered thaumatin with a liquid form reduced symptoms among the rhinitic workers. Although gum arabic is a well-known potential allergen, we were unable to find prior documentation of allergic symptoms to thaumatin when it is used in the food industry.

Epithelial cells as alternative human biomatrices for comet assay

The comet assay is a valuable experimental tool aimed at mapping DNA damage in human cells in vivo for environmental and occupational monitoring, as well as for therapeutic purposes, such as storage prior to transplant, during tissue engineering, and in experimental ex vivo assays. Furthermore, due to its great versatility, the comet assay allows to explore the use of alternative cell types to assess DNA damage, such as epithelial cells. Epithelial cells, as specialized components of many organs, have the potential to serve as biomatrices that can be used to evaluate genotoxicity and may also serve as early effect biomarkers. Furthermore, 80% of solid cancers are of epithelial origin, which points to the importance of studying DNA damage in these tissues. Indeed, studies including comet assay in epithelial cells have either clear clinical applications (lens and corneal epithelial cells) or examine genotoxicity within human biomonitoring and in vitro studies. We here review improvements in determining DNA damage using the comet assay by employing lens, corneal, tear duct, buccal, and nasal epithelial cells. For some of these tissues invasive sampling procedures are needed. Desquamated epithelial cells must be obtained and dissociated prior to examination using the comet assay, and such procedures may induce varying amounts of DNA damage. Buccal epithelial cells require lysis enriched with proteinase K to obtain free nucleosomes. Over a 30 year period, the comet assay in epithelial cells has been little employed, however its use indicates that it could be an extraordinary tool not only for risk assessment, but also for diagnosis, prognosis of treatments and diseases.

Advances in asthma drug discovery: evaluating the potential of nasal cell sampling and beyond

INTRODUCTION

Inhaled corticosteroid anti-inflammatory therapy is effective at controlling disease symptoms of asthma, but a subset of patients remains symptomatic despite optimal treatment, creating a clear unmet medical need. Moreover, none of the currently available drugs for asthma are really disease-modifying or curative. Although murine models of asthma, based on transgenic and knockout animals, may offer an integrated pathophysiological system for studying the characteristics of airway inflammation and hyperresponsiveness, these alterations are noteworthily different compared with those observed in asthmatic patients. Since a clear functional and inflammatory relationship between the nasal mucosa and bronchial tissue in patients suffering from asthma and allergic rhinitis has been recognized, using preclinical models based on human nasal cells sampling might support a prompt and effective anti-inflammatory drug discovery in asthma.

AREAS COVERED

The authors provide a review, which discusses the potential role of nasal cell sampling and its application in advanced drug discovery for asthma. The contents range from the similarities and differences between asthma and allergic rhinitis up to artificial airway models based on sophisticated human lung-on-a-chip devices.

EXPERT OPINION

Nasal cell sampling and processing have reached a great potential in asthma drug discovery. The authors believe that models of asthma, which are based on human nasal cells, can provide valuable indications of proof of pharmacological and potential therapeutic efficacy in both preclinical and early clinical settings.

Eosinophils and mast cells: a comparison of nasal mucosa histology and cytology to markers in nasal discharge in patients with chronic sino-nasal diseases

Allergic rhinitis (AR), nasal polyps (NP) as well as chronic rhinosinusitis (CRS) are all known to be associated with eosinophilic infiltration and elevated numbers of mast cells (MC) within the mucosa. Both cell types and their markers eosinophilic cationic protein (ECP) and tryptase are utilized in the diagnosis and management of chronic sino-nasal diseases. Mucosal cytology samples were gathered by cytobrush, histological samples were obtained from the inferior turbinate. In both sample sets, the number of eosinophils and MC was determined. Their corresponding markers ECP and tryptase were quantified from nasal discharge. Patients were grouped with reference to their main diagnosis: AR (n = 34), NP (n = 25), CRS (n = 27) and controls (n = 34). Eosinophil counts from cytobrush and ECP levels were significantly elevated in NP compared to all other groups-31- and 13-fold over control, respectively. However, histologic review did not reveal any difference in eosinophil count among groups. Tryptase was significantly elevated threefold in AR versus CRS and controls. No correlation to cytological and histological MC counts could be found. ECP levels in nasal discharge as well as eosinophil counts can provide useful information with regard to the diagnosis. Likewise, tryptase concentrations can do. The presented data show that the measurement of markers in nasal discharge is superior in differentiating among diagnosis groups. Given that the collection of nasal secretions is more comfortable for patients than the more invasive techniques, we recommend first line ECP and tryptase testing performed on nasal secretions.

Diagnostic accuracy of brush cytology in canine chronic intranasal disease

BACKGROUND

Most cases of canine chronic intranasal disease cannot be differentiated based on clinical examination alone, and biopsy is often required for a definitive diagnosis. Nonsurgical cytologic and histologic biopsy techniques represent desirable diagnostic approaches.

OBJECTIVE

The aim of this retrospective study was to determine the diagnostic accuracy of brush cytology in differentiating non-neoplastic and neoplastic diseases in dogs with chronic intranasal disease.

METHODS

Cytologic samples of lesions in dogs with chronic intranasal disease were obtained by brushing over a 12-year period. All dogs had complete physical examinations as well as radiographic, rhinoscopic, and cytologic evaluation. Histologic diagnosis, follow-up clinical information, or both were used as the gold standard, and dogs free of disease or with no progression of disease at 1 year were considered negative for neoplasia. Indicators of performance of brush cytology in detecting neoplasia were calculated and included sensitivity, specificity, positive and negative likelihood ratios, and diagnostic odds ratio.

RESULTS

Samples of nasal brushings from 138 dogs were evaluated. Of 62 cases of neoplastic disease, true-positive and false-negative diagnoses were made using cytologic evaluation in 44 (71.0%) and 18 (29.0%) cases, respectively. False-negative diagnoses of neoplasia were not attributed to low cellularity, but to the presence of inflammatory cells that masked neoplastic cells. Brush cytology had a sensitivity of 0.71, specificity of 0.99, positive likelihood ratio of 53.94, negative likelihood ratio of 0.29, and diagnostic odds ratio of 188.33.

CONCLUSIONS

Brush cytology has good diagnostic accuracy for chronic intranasal lesions in dogs.

Intersession repeatability of a novel nasal lavage technique

This study describes a novel nasal lavage method using a pediatric tracheostomy tube and examines intersession repeatability for several clinically and technically relevant parameters. Fourteen healthy subjects were included in this study. Both nasal cavities were washed using a standard amount of saline solution (7 mL) via a pediatric tracheostomy tube, and the 2 samples were pooled for measurement of cytokine concentrations and cell count. Recovery volume was also recorded. For each subject, measurements were repeated on 5 consecutive days. Intersession repeatability of recovery volume, cell count, and cytokine concentrations interleukin (IL)-6 and IL-8 were expressed in terms of mean coefficient of variation, intraclass correlation coefficient, and interitem correlations. Intraclass correlation coefficients and interitem correlation coefficients indicated almost perfect agreement for cell count and IL-8 concentrations. Recovery volume and IL-6 concentrations were more variable. The mean coefficient of variation was low for cell count (2%), IL-8 concentration (3%), and recovery volume (3%), whereas the mean percentage recovery was high (87%). This newly developed nasal lavage technique is repeatable over successive sessions for cytokine concentrations and cell counts in nasal secretions of healthy subjects. This method might be valuable in the study of inflammatory conditions involving the upper respiratory tract.

Diagnostic tools in Rhinology EAACI position paper

This EAACI Task Force document aims at providing the readers with a comprehensive and complete overview of the currently available tools for diagnosis of nasal and sino-nasal disease. We have tried to logically order the different important issues related to history taking, clinical examination and additional investigative tools for evaluation of the severity of sinonasal disease into a consensus document. A panel of European experts in the field of Rhinology has contributed to this consensus document on Diagnostic Tools in Rhinology.

Limited airway effects in mild asthmatics after exposure to air pollution in a road tunnel

Ambient air pollution is a contributing factor to respiratory morbidity and mortality and asthmatics are a particularly vulnerable population. The aim of the study was to investigate whether acute exposure to traffic related air pollution in a road tunnel would increase bronchial responsiveness in mild asthmatics, and if this would be accompanied by increased measures of inflammatory markers in the airways assessed by nasal lavage (NAL) and induced sputum. Fourteen mild asthmatics (7 treated with inhaled corticosteroids) were exposed for 2 h in a road tunnel and a control environment, respectively, separated by at least 3 weeks. Symptoms and peak expiratory flow (PEF) were recorded. Seven hours following exposure sessions, subjects underwent measurements of fraction of exhaled nitric oxide (FENO), spirometry, and a bronchial provocation test. NAL, induced sputum and blood samples were collected. The median PM(2.5) and PM(10) levels during the exposure occasions in the road tunnel were 80 (range 41-93) μg/m(3) and 183 (72-213) μg/m(3) respectively. Irritative symptoms from the airways increased and PEF decreased after road tunnel exposure. Increased levels of IL-10, IL-12 and TNF-α were observed in NAL fluid from subjects without ongoing inhaled corticosteroid treatment. Forced expiratory volume in 1 s (FEV(1)) and the degree of bronchial responsiveness in asthmatics did not change significantly after tunnel exposure. We conclude that asthmatics exhibit increased symptoms, decreased PEF and signs of inflammatory response in the upper airways, after a 2 h road tunnel exposure. Our findings may further emphasize asthmatics as a vulnerable group to common air pollutants.

Noninvasive methods for assessment of airway inflammation in occupational settings

The present document is a consensus statement reached by a panel of experts on noninvasive methods for assessment of airway inflammation in the investigation of occupational respiratory diseases, such as occupational rhinitis, occupational asthma, and nonasthmatic eosinophilic bronchitis. Both the upper and the lower airway inflammation have been reviewed and appraised reinforcing the concept of 'united airway disease' in the occupational settings. The most widely used noninvasive methods to assess bronchial inflammation are covered: induced sputum, fractional exhaled nitric oxide (FeNO) concentration, and exhaled breath condensate. Nasal inflammation may be assessed by noninvasive approaches such as nasal cytology and nasal lavage, which provide information on different aspects of inflammatory processes (cellular vs mediators). Key messages and suggestions on the use of noninvasive methods for assessment of airway inflammation in the investigation and diagnosis of occupational airway diseases are issued.

Assessment for microsatellite DNA instability in nasal cytology samples of patients with allergic rhinitis

BACKGROUND

Genetic alterations, including microsatellite instability (MSI) and loss of heterozygosity (LOH), have been described in both malignant and benign diseases. Previous studies have successfully detected such alterations in sputum samples of patients with bronchial asthma (BA). The aim of this study was to assess the presence of MSI and/or LOH in nasal cytology samples of patients with allergic rhinitis (AR).

METHODS

Nasal brush samples and peripheral blood from 20 patients with AR were analyzed. DNA was extracted and analyzed for MSI and LOH using the following microsatellite markers: D16S289, D4S2394, D4S1651, DXS8039, D3S3606, and D2S2113, harboring potential susceptibility genes for AR and atopy. Microsatellite analysis was performed also in eight control subjects.

RESULTS

No MSI and/or LOH were noted in either the AR or the control group.

CONCLUSION

Although MSI and LOH are detectable phenomena in sputum samples of patients with BA, this seems not to be the case for nasal cytology samples of patients with AR. Additional studies are needed, using a larger number of polymorphic markers, to assess if such a difference exists among two diseases otherwise very closely related.

Inhibition of macrophage apoptosis by Neisseria meningitidis requires nitric oxide detoxification mechanisms

Host-driven macrophage apoptosis contributes to innate immunity during bacterial infection. Neisseria meningitidis inhibits apoptosis in a variety of cells, but its impact on macrophage apoptosis is unknown. We demonstrate that N. meningitidis prevents macrophage apoptosis via genes encoding nitric oxide detoxification and a porin, PorB.

Effects of 5-lipoxygenase inhibitor zileuton on airway responses to inhaled swine house dust in healthy subjects

BACKGROUND

Inhalation of swine house dust induces acute airway inflammation and increased bronchial responsiveness in healthy subjects.

OBJECTIVE

The aim of the study was to investigate whether 5-lipoxygenase products such as leukotrienes may have a role in this reaction.

METHODS

Twenty-three healthy subjects were randomised into two groups receiving treatment with either zileuton (600 mg) or placebo four times a day. After 5 days of treatment, all subjects were exposed for 3h in a swine barn. Bronchial responsiveness, exhaled nitric oxide (NO), and mediators in nasal lavage (NAL), blood and urine were measured before and after the exposure.

RESULTS

The exposure induced an increased bronchial responsiveness to methacholine in both groups with 2-3 doubling concentration steps, no significant difference between treatments. Leukotriene E(4) in urine increased significantly following exposure in the placebo group from 37.3 (29.1-45.6) (mean (95% confidence interval)) ng/mmol creatinine to 47.7 (36.3-59.0) ng/mmol creatinine (P<0.05), but not in the zileuton group. The post-exposure increase of LTB(4) levels in NAL fluid was totally abolished in the zileuton group (P<0.05 vs. the placebo). The levels of exhaled NO increased significantly (P<0.01), two-fold in both groups. The PGD(2) metabolite 9alpha, 11beta-PGF(2) increased in placebo-treated subjects (P<0.01; P<0.05 vs. zileuton), strengthening mast cell participation. Neutrophil counts and levels of IL-6 in peripheral blood increased in both groups, with a significantly larger increase in zileuton treated subjects (P<0.05 and P<0.001, respectively compared to placebo).

CONCLUSIONS

Pre-treatment with clinically recommended doses of the 5-lipoxygenase inhibitor zileuton did not affect the increase of bronchial reactivity induced by swine dust exposure. The intervention totally abolished the LTB(4) release in NAL fluid, but only partially inhibited the formation of leukotrienes as monitored by urinary levels. The enhanced increase of neutrophils and IL-6 in peripheral blood in the zileuton group, suggests that inhibition of 5-lipoxygenase may have pro-inflammatory effects.

Association between atmospheric ozone levels and damage to human nasal mucosa in Florence, Italy

We evaluated the effects of urban air pollutants on human nasal mucosa over an 8-month period on 102 subjects living in Florence, Tuscany, Italy. A group of subjects living in a city with a lower level of pollution (Sassari, Sardinia, Italy) was also analyzed. Nasal mucosa cells were harvested by brushing, a noninvasive procedure. Half of the cells were used for genotoxicity studies using the alkaline comet assay, and half for morphological studies. The levels of DNA damage in the nasal mucosa were considerably higher (+73%) in the subjects living in Florence than in Sassari. High levels of atmospheric ozone in Florence air correlated with DNA damage, and to the prevalence of inflammatory pathologies of the upper respiratory tract, although the ozone concentrations were below the Italian recommended attention level. Furthermore, higher levels of DNA damage were correlated with a dysfunction in the ability to maintain a normal epithelial cell structure. These data suggest an association between ozone air levels and damage in the upper respiratory tract. It remains unclear whether ozone itself or other associated pollutants are responsible for the observed alterations.

Airways inflammation after exposure in a swine confinement building during cleaning procedure

BACKGROUND

Healthy volunteers exposed for 3 hr during weighing of pigs develop an airway inflammation characterized by a massive influx of neutrophilic granulocytes in the upper and lower airways and increased bronchial responsiveness to methacholine. The purpose of the present study was to investigate health effects from exposure during cleaning of the swine confinement building and to evaluate the effect of a respiratory protection device.

METHODS

Sixteen subjects were exposed for 3 hr during cleaning of a swine confinement room with a high-pressure cleaner. Seven out of sixteen subjects were equipped with a mask during exposure.

RESULTS

The bronchial responsiveness increased in all subjects following exposure, significantly more in the group exposed without a mask (P < 0.05). The cell concentration (mainly neutrophilic granulocytes) in nasal lavage fluid as well as the concentration of interleukin-8, increased significantly only in those subjects exposed without a respiratory protection device. In peripheral blood, an increase of neutrophilic granulocytes was observed in both groups, although it was significantly higher in the group without mask (P < 0.05). The inhalable dust level was 0.94 (0.74 - 1.55) mg/m(3) and respirable dust 0.56 (0.51-0.63) mg/m(3).

CONCLUSION

Exposure to dust aerosols during the cleaning of the interior of a swine confinement building induces increased bronchial responsiveness and an acute inflammatory reaction in the upper airways. The use of a mask attenuated but did not abolish the inflammatory response. This suggests that gases and/or ultrafine particles in this environment could be important factors in the development of increased bronchial responsiveness.

Sodium cromoglycate attenuates pulmonary inflammation without influencing bronchial responsiveness in healthy subjects exposed to organic dust

BACKGROUND

Inhalation of organic dust from a pig house induces airway inflammation and increases bronchial responsiveness to methacholine in healthy subjects.

OBJECTIVE

To study whether sodium cromoglycate influences the airway inflammatory reaction and the increase in airway responsiveness induced by inhalation of organic dust.

METHODS

Bronchoalveolar and nasal lavages, and bronchial methacholine challanges were performed and blood samples were drawn in 32 healthy subjects before and after exposure to dust in a pig farm. Sodium cromoglycate was inhaled (20 mg, twice a day) and administered intranasally (5.2 mg, twice a day) by 16 and a corresponding placebo was given to the other 16 healthy controls for two weeks prior to exposure.

RESULTS

Exposure induced a significant increase in inflammatory cells and soluble components (pro-inflammatory cytokines, inflammatory mediators) in bronchoalveolar and nasal lavage fluid in both groups. The increase in neutrophils, interleukin (IL)-6 and tumour necrosis factor (TNF)-alpha as well as myeloperoxidase and soluble intracellular adhesion molecule (ICAM)-1 in bronchoalveolar lavage (BAL) fluid was significantly reduced by treatment with sodium cromoglycate. Although sodium cromoglycate inhalation largely influenced a variety of inflammatory indices in bronchoalveolar lavage fluid it had no effect on the increase in bronchial responsiveness to methacholine.

CONCLUSION

Sodium cromoglycate alters the airway inflammatory response to inhaled organic dust without influencing the dust-induced increase in bronchial responsiveness to methacholine.

Nasal provocation testing: a review

OBJECTIVE

This review focuses on the uses of nasal provocation testing (NPT) for scientific investigations of the mechanisms of allergic and nonallergic rhinitis. It also describes the use of NPT as a diagnostic tool in clinical practice. The indications, contraindications, advantages, and limitations of different techniques for evaluation of nasal responses are reviewed. The paper familiarizes investigators with particulars of different nasal delivery systems, provocation agents, nasal patency measurements, secretion collection, and nasal lavage techniques.

DATA SOURCES

Relevant publications obtained from a literature review.

STUDY SELECTION

Relevant publications on the topics of NPT, allergic, and nonallergic rhinitis were critically evaluated.

RESULTS AND CONCLUSIONS

To date, NPT has been used primarily as a research tool for the investigation of allergic and nonallergic rhinitis with a wide variety of techniques depending on the specific scientific purposes. NPT will continue to provide useful information about the pathogenesis of airway diseases. Standardized nasal provocation testing has the potential to become a more frequently used clinical test in the diagnosis of allergic and occupational rhinitis and for determination of the appropriate and focused therapy.

Effect of topical corticosteroids on seasonal increases in epithelial eosinophils and mast cells in allergic rhinitis: a comparison of nasal brush and biopsy methods

BACKGROUND

Nasal brushing and nasal biopsy are well-tolerated sampling techniques. Seasonal grass pollen-induced rhinitis is characterized by epithelial mast cell infiltration and seasonal increases in both epithelial and sub-mucosal eosinophils.

OBJECTIVE

To compare the ability of the nasal brush and nasal biopsy techniques to detect natural seasonal increases in eosinophils and mast cells, and to assess the influence of topical corticosteroid.

METHODS

Nasal brush samples and nasal biopsies were collected from 46 grass pollen-sensitive seasonal rhinitis patients before the grass pollen season and at the peak of the pollen season following 6 weeks' treatment with either fluticasone propionate aqueous nasal spray (200 microg, twice daily) or placebo nasal spray.

RESULTS

Placebo patients showed seasonal increases in epithelial eosinophils both with nasal brushing (P < 0.0001) and biopsy (P < 0.001). Epithelial mast cell numbers also increased during the pollen season as detectable by brushing (P < 0.0001) and biopsy (P < 0.03). Changes in cell numbers measured by nasal brushing correlated with those observed with nasal biopsy, both for eosinophils and mast cells (P < 0.05). Sub-mucosal eosinophils but not mast cells also increased during the pollen season (P < 0.002). Nasal brushing and biopsy revealed that fluticasone treatment inhibited seasonal increases in epithelial eosinophils (P < 0.00001) and epithelial infiltration by mast cells (nasal brushing P < 0.00001 and nasal biopsy P < 0.01). Fluticasone also inhibited seasonal increases in sub-mucosal eosinophils (P < 0.001) and significantly reduced nasal symptoms (P < 0.001).

CONCLUSION

Nasal brushing harvests sufficient inflammatory cells from the surface of the nasal mucosa to be used in lieu of nasal biopsies in observation of the effect of drugs on the nasal epithelium.

Circulating eosinophil/basophil progenitors and nasal mucosal cytokines in seasonal allergic rhinitis

Accumulation of eosinophils in the airways is characteristic of allergic rhinitis and asthma. The tissue eosinophilia may involve both recruitment of mature eosinophils and proliferation of their progenitors. This study examines mature eosinophils (nasal and circulating), their circulating progenitors, and a potential role of granulocyte-macrophage colony-stimulating factor (GM-CSF) in stimulating these progenitors. Twelve subjects with a history of seasonal allergic rhinitis and positive skin prick test for birch pollen were studied during four periods: shortly before, in the early and intense phase, at the end, and well after the Swedish birch-pollen season. Nasal mucosal and circulating eosinophils were examined in both nasal brushings and peripheral blood samples. Eosinophil/basophil progenitors were determined by counting colony-forming units in nonadherent mononuclear blood-cell cultures in methylcellulose at 14 days. The nasal mucosal cytokines GM-CSF, interleukin (IL)-1beta, IL-3, IL-5, IL-6, IL-8, and RANTES were analyzed (ELISA) in nasal lavage (NAL) fluids. All patients developed severe symptoms of rhinitis at the height of the season, with increased numbers of eosinophils in the nasal mucosa (P<0.05) and in the circulation (P<0.05). At this time point, the number of circulating progenitors (P<0.05) and the NAL fluid level of GM-CSF (P<0.05) were also increased. In contrast, there was no change in the NAL fluid levels of IL-1beta, IL-3, IL-6, or IL-8. Neither IL-5 nor RANTES could be detected in any of the NAL fluids. At the end of or after the season, there was no increase in nasal eosinophils or circulating eosinophils or progenitors (P>0.05). Ex vivo addition of GM-CSF (10-100 U) increased the number of blood progenitors grown before (P<0.01) and after (P<0.05) the season, compared with during the season. The in vitro GM-CSF responsiveness of progenitors may be related to whether or not these already have been stimulated endogenously by GM-CSF. Taken together, our data thus suggest that GM-CSF may play a role in vivo to increase production of eosinophilic progenitors in allergic airway disease.

Airway responses in naive subjects to exposure in poultry houses: comparison between cage rearing system and alternative rearing system for laying hens

BACKGROUND

Workers in the poultry industry have increased frequencies of respiratory health problems. The aim of the present study was to investigate acute health effects from exposure in poultry houses and to compare the health effects observed in a cage rearing system and the alternative "cage-less" rearing system for laying hens.

METHODS

Thirty-four subjects were exposed for 3 hr in confined poultry houses. The subjects were randomized into three groups: one was exposed in a building with a cage rearing system and the two other groups were exposed in buildings with a cage-less system, with either young hens and fresh bedding material or with older hens and old bedding material.

RESULTS

Inhalable dust levels were approximately 4 mg/m3 in the buildings with the cage-less system and 2 mg/m3 in the building with cage rearing system; the endotoxin concentration was approximately 100 ng/m3 in both systems. Bronchial responsiveness to methacholine increased approximately fivefold in all groups following exposure. The concentration of the proinflammatory cytokine interleukin-6 (IL-6) increased in nasal lavage fluid and in peripheral blood as a result of the exposure. The number of leukocytes in peripheral blood increased only in the groups exposed among loose laying hens.

CONCLUSION

In the present study, we have demonstrated among previously non-exposed subjects, that 3-hr exposure in confined buildings for egg production induces an acute inflammatory reaction in the upper airways and increased bronchial responsiveness. There is a tendency towards stronger reactions in the groups exposed in the buildings with loose housing for laying hens.

Evaluation of brush cytology in the diagnosis of chronic intranasal disease in cats

Brush cytology was used as a diagnostic aid in 85 cats affected with chronic intranasal disease. Fifty-three of these cases, sampled over a five-year period, were included in this study, while the other cases were excluded due to poor cellularity of the cytological samples (nine cases) or a lack of histological or follow-up data (23 cases). Thirty-six brush samples were classified by cytology as inflammatory. Subsequent histological examination revealed a false negative diagnosis of neoplasia in six cats, two of which had malignant tumours (one adenocarcinoma and one lymphoma), the remaining four having benign tumours (two adenomas and two osteochondromas). Seventeen samples were classified by brush cytology as neoplastic. This was confirmed in 16 of these cases by histology or follow-up (nine epithelial malignant tumours, six lymphomas and one osteosarcoma). In the remaining case, a false positive diagnosis of lymphoma was made. The procedure had an overall 86.8 per cent (46/53) agreement between the diagnosis of inflammatory conditions versus neoplasia, with a sensitivity of 72.7 per cent, a specificity of 96.8 per cent, a predictive value of a positive test of 94.1 per cent and a predictive value of a negative test of 83.3 per cent.

In vitro cell models to study nasal mucosal permeability and metabolism

Whereas in vivo studies represent the most crucial test for any nasal drug application or formulation, mechanistic aspects of nasal absorption may be more clearly approached by well defined and controlled in vitro studies. In this review the progress of nasal in vitro models to investigate drug permeation and metabolism in the epithelium is summarized and their potential and limitations are discussed. The following subjects will be covered: (i) primary cell cultures of human nasal epithelium, including sampling techniques and culture conditions, (ii) human nasal cell lines (in particular the human nasal cell line RPMI 2650), and (iii) excised nasal epithelium (rabbit, bovine, ovine, canine, human), also summarizing suitable preparation techniques and tissue characterization, test media, tissue equilibration, viability testing, and integrity tests. Furthermore, an overview on the various experimental set-ups suitable for in vitro transport studies (permeation rates; identification of permeation pathways; mechanisms and toxicity of absorption enhancers) and for metabolism studies (rates, saturation and pathways of enzymatic cleavage) is presented. Some attention is given to identify potential endocytotic uptake mechanisms. To date, the permeation and metabolic barrier function of excised nasal tissue derived from various animals has shown to mimic the in vivo situation 'ex vivo' at the highest degree possible. Supply of human tissue will continue to be short. Therefore, further studies are necessary to evaluate and improve culture conditions, handling, performance and physiologic relevance of primary human cell and cell line cultures.

Nasal metachromatic cells in infancy in relation to the appearance of atopic disease during the first 6 years of life

The relationship between the appearance of nasal metachromatic cells (basophils and mast cells) during the first 18 months of life and the development of respiratory and other allergic diseases up to 6 years of age was studied prospectively in 67 children. Follow-up was done at 3, 6, 9, and 18 months and 6 years. Of the 31 children who had detectable metachromatic cells in the nasal mucosa during infancy, 18 had atopic manifestations at 6 years (58%), two were probably atopic (6%), and 11 (36%) were nonatopic. The corresponding numbers for the 33 children without detectable metachromatic cells during infancy were 10 atopic (30%), two probably atopic (6%), and 21 nonatopic (64%) at 6 years (P < 0.05). Children having detectable nasal metachromatic cells at every examination were more often allergic than children with no detectable cells at any time during the 6-year follow-up period (P < 0.05). In contrast, nasal metachromatic cells were equally commonly demonstrated at 6 years in children with and without current atopic manifestations. We conclude that metachromatic cells appear at an earlier age in the nasal mucosa of atopic than nonatopic infants. The observation further supports the existence of a primary immunologic abnormality in atopic patients as related to allergic inflammatory responses. The diagnostic efficacy of this marker was too low, however, to be clinically useful as a predictor of allergy.

Effect of exposure to swine dust on levels of IL-8 in airway lavage fluid

BACKGROUND

Inhalation of swine dust causes airway inflammation with influx of inflammatory cells, predominantly neutrophils, into the lungs. A study was undertaken to determine whether or not exposure to swine dust induces release of interleukin 8 (IL-8) into upper and lower airways and how this possible release is related to cellular influx. A further aim was to study the relationship between the inflammatory response and swine dust exposure.

METHODS

Thirty one healthy, non-smoking, previously unexposed subjects were exposed to swine dust during three hours work in a swine house. Bronchoalveolar lavage (BAL) was performed two weeks before and 24 hours after the exposure (n = 16). Nasal lavage and acoustic rhinometry were carried out 1-2 hours before and seven hours after the start of the exposure (n = 31). Exposure measurements were performed with personal sampling equipment.

RESULTS

The exposure led to 19-fold and 70-fold increases in the neutrophil concentrations in nasal lavage and BAL fluid, respectively (p < 0.001). In BAL, fluid macrophages, lymphocytes and eosinophils increased significantly. The IL-8 levels in BAL fluid increased from < 31.3 ng/l to 63 (43-109) ng/l (median (25-75th percentile), p < 0.001), and in nasal lavage fluid the concentrations increased from 144 (97-227) ng/l to 1064 (864-1437) ng/l (p < 0.001). IL-8 levels showed a significant correlation with the increase in neutrophils in the nasal lavage fluid but not in the BAL fluid. Acoustic rhinometry demonstrated significant swelling of the nasal mucosa. The air concentration of inhalable dust was 23.3 (20.0-29.3) mg/m3, endotoxin 1.3 (1.1-1.4) micrograms/m3, and muramic acid 0.99 (0.78-2.1) microgram/m3.

CONCLUSIONS

The concentration of IL-8 increases in BAL fluid and nasal lavage fluid following exposure to swine dust and may be one of the chemoattractants contributing to the recruitment of neutrophils to the nasal cavity and the alveolar space.

Acute effects of exposure to air contaminants in a sawmill on healthy volunteers

OBJECTIVES

To study whether air contaminants in sawmills can induce acute changes in the upper and lower airways of previously non-exposed subjects.

METHODS

Nineteen healthy volunteers were examined to find the concentration of interleukin 6 (IL-6) in nasal lavage fluid and lung function before and after five hour exposure to dusts and fumes generated in a sawmill where timber from Scots pine was sawed. When exposed, the subjects had respirators with and without a particle filter.

RESULTS

The median for daily time weighted average concentration of total dust for subjects with respirators without a filter was 0.13 mg/m3, which was significantly higher than the median of 0.04 mg/m3 for subjects who had respirators with a filter. The median for the concentration of IL-6 in the nasal lavage fluid increased after exposure from 0.5 to 5.9 pg/ml in subjects with respirators without a particle filter (P < 0.05). The increase of the concentration of IL-6 was significantly correlated with the dust concentration. A decrease in transfer factor of the lung was significantly correlated with daily time weighted average concentrations of terpenes.

CONCLUSION

The findings suggest that healthy volunteers, exposed to air contaminants in a sawmill, show a slight inflammatory reaction. Also, the results of the study indicate the importance of decreasing the concentrations of wood dust in the work environment.

The (alpha2-->8)-linked polysialic acid capsule of group B Neisseria meningitidis modifies multiple steps during interaction with human macrophages

Group B Neisseria meningitidis causes systemic disease, including meningitis, after initial colonization and subsequent penetration of nasopharyngeal mucosa, a tissue which is richly populated by macrophages. In an initial effort to characterize the interaction of N. meningitidis and mature human macrophages, the influence of the alpha2-->8) -linked polysialic acid capsule on the interaction of N. meningitidis with human monocyte-derived macrophages was investigated with a capsulate case isolate and an isogenic Tn916-derived noncapsulate transformant. The capsulate strain was fourfold less adherent to the macrophage surface after cold incubation, although adherence of both strains was significantly increased after opsonization with nonimmune C5-depleted serum. When opsonized inocula were adjusted so that they adhered to macrophages in equal numbers, the two strains were internalized at equivalent rates and both entered membrane-bound compartments (phagosomes). Colocalization of bacteria with the late endosomal and lysosomal marker lysosome-associated membrane protein revealed that fusion of lysosomes with phagosomes containing the capsulate organism was significantly reduced 10 and 30 min after entry, but by 1 h, no difference between the strains was observed. Once internalized, meningococci were effectively killed, although more rapid killing of the capsulate strain was observed over the first 3 h. These results indicate that the (alpha2-->8)-linked polysialic acid capsule modifies the interaction of meningococci with human macrophages at multiple steps, including adherence to the macrophage surface and phagosome-lysosome fusion. Moreover, the discordance between the kinetics of phagosome- lysosome fusion and bacterial killing suggests that a nonlysosomal mechanism may be responsible for a significant fraction of macrophage killing of N. meningitidis.

Various methods for testing nasal responses in vivo: a critical review

Mucosal responses in the airway can ideally be studied in the nose. It is a readily accessible organ and can be provoked repeatedly. Likewise, mucosal responses to certain provocations can be easily monitored. Different methods for the provocation and measurement of nasal responses have been used in recent years. Each technique has its own advantage and restrictions. In order to make a correct interpretation of the results achieved, however, it is important that the investigator is familiar and comfortable with the methods used. For clinical purposes, techniques for qualitative measurements may be appropriate, but for experimental research, quantitative measurements with high reproducibility are essential. The present paper critically discusses current techniques for provocation and assessment of nasal responses, which may improve both the techniques used and the understanding of nasal physiology.

Metachromatic, IgE-bearing and tryptase-containing cells on the nasal mucosal surface in provoked allergic rhinitis

We studied the relationship between mast cells or basophils and symptoms in provoked allergic rhinitis. Nasal brush and lavage samples were obtained before nasal allergen challenge and every 2 h for 12 h after the challenge in 10 allergics and 3 controls. The cells were identified by their metachromatic staining properties (brush and lavage samples) or with immunohistochemical methods using specific antibodies to IgE and tryptase, a selective mast-cell marker (brush samples). Histamine was determined in the brush samples using liquid chromatography. After an initial decrease, the numbers of metachromatic, IgE-bearing and tryptase-containing cells, as well as the histamine content of the cells in the brush samples, increased during the subsequent observation hours. The prechallenge cell and histamine values correlated with the symptom score 15 min after the challenge. The prechallenge lavage samples lacked metachromatic cells, but these cells were found in increasing numbers after the provocation. Three of the patients differed from the remaining seven in that their prechallenge brush samples contained many positively stained cells. All patients showed a positive cellular response to the allergen challenge, but these three individuals showed the most vivid response. The morphology of the metachromatic cells in the prechallenge brush samples agreed with that of mast cells, but the morphology of metachromatic cells which outnumbered tryptase-containing cells in samples at 8 to 12 h rather agreed with their being basophils.

Mast cells and eosinophils in the allergic mucosal response to allergen challenge: changes in distribution and signs of activation in relation to symptoms

An allergen challenge was performed in 10 asymptomatic patients with strictly seasonal allergic rhinitis. For comparison; seven nonallergic subjects were challenged with allergen, and seven allergic patients were challenged with diluent. Cell samples, obtained with use of a brush technique to recover cells from within the epithelium and nasal lavage to collect cells from the epithelial surface, and symptom scores were taken before challenge and at 2-hour intervals during 12 hours. The cell suspensions were cytocentrifuged onto object slides for light microscopy. Histamine was determined in the cell pellets. In brush samples from the allergic patients challenged with allergen, eosinophils, expressed as a percentage of the total granulocytes, increased from 4.3% +/- 2.7% (mean +/- SEM) to 10.3% +/- 3.8% (p < 0.05) 4 hours after challenge. This level was maintained for up to 12 hours. A similar increase was noted in the lavage specimens 2, 6, and 8 hours after the challenge. In the brush samples the proportion of eosinophils containing two or more cytoplasmic vacuoles, taken as a sign of activation, increased from 20% to 72% (p < 0.05) 8 hours after provocation. In brush samples from the allergic patients challenged with allergen, the numbers of metachromatic cells increased to a maximum of eightfold at 10 hours. In the lavage specimens, no metachromatic cells were observed before provocation, but they progressively increased in number 2 to 12 hours after provocation. Cell pellet histamine content decreased temporarily 2 to 4 hours after challenge (p < 0.05) in brush samples from allergen-challenged allergic patients. The local metachromatic cell density before challenge, as reflected in the brush specimens, correlated with nasal congestion, sneezing, and the degree of eosinophilia.

Indirect evidence of nasal inflammation assessed by titration of inflammatory mediators and enumeration of cells in nasal secretions of patients with chronic rhinitis

Pathophysiologic mechanisms of perennial rhinitis are poorly understood. The characterization of inflammation was studied in nasal lavage of patients with perennial rhinitis by the enumeration of cells involved in the allergic inflammation and the measurement of six mediators released in nasal secretions to determine whether some mediators were relevant for the etiologic diagnosis and the occurrence of symptoms. Ten healthy subjects and 57 patients with perennial rhinitis were placed into four groups according to the symptoms they presented at the time of the study and the origin of the allergy. Allergy was characterized by the history, skin prick tests to standardized allergens, and RAST. Eosinophil protein X (EPX), tryptase, histamine, myeloperoxidase, prostaglandin D2, and leukotriene C4/D4 (LTC4/D4) were measured in nasal lavage by enzyme assay or radioimmunoassay. Eosinophils and neutrophils were enumerated after cytocentrifugation of the lavage fluid and May Grunwald Giemsa staining. Tryptase, myeloperoxidase and EPX but not histamine levels were increased in all four patient groups. Eosinophils, LTC4/D4, and prostaglandin D2 were significantly (p < 0.001, p < 0.03, and p < 0.01) increased in allergic and symptomatic patients. EPX was significantly increased in symptomatic allergic and nonallergic patients. This study suggests the involvement of mast cells, neutrophils, and eosinophils, but the latter cells appear to have a more prominent role. The importance of EPX and LTC4/D4 in the characterization of chronic symptomatic rhinitis was also observed.

Distribution of eosinophils in the nose in patients with perennial rhinitis

The traditional method of classifying perennial rhinitis into eosinophilic and non-eosinophilic is by taking a single nasal smear from one nostril. In the light of personal experience it was felt that this method of sampling may be inadequate. The present study included 20 patients with perennial rhinitis undergoing nasal surgery. Serum total IgE levels were taken and those above 40 IU/ml had allergen specific IgE measured. Nasal smears and biopsies were taken from 5 sites on each side of the nose; middle and inferior turbinates and post nasal space. The smears significantly correlated with the biopsies (rs = 0.446, P < 0.001). The distribution of eosinophils between and within nasal cavities was found to differ. Representative sampling of the nose is important for accurate eosinophil expression. The definition of an eosinophil rich and poor nose requires greater clarification as it has great clinical relevance regarding management.

Eosinophil chemotactic activity of topical PAF on the human nasal mucosa

Ten patients with strictly seasonal allergic rhinitis were challenged with 132 micrograms PAF-acether in each nasal cavity outside their relevant pollen season. Cells from the nasal mucosa were collected by nasal lavage prior to and every second hour up to 8 h after the PAF challenge. At the same times the volume of methacholine-induced secretory responsiveness was measured. A brush specimen was harvested from the nasal mucosa prior to and 8 h after the PAF challenge. PAF led to an increase in the number of eosinophils from an initial 6.1 to 64.4 per glass 2 h later. The number of eosinophils in the nasal lavage fluid then decreased to its initial baseline value. By 8 h after PAF challenge the number of eosinophils collected with the brush was still elevated as compared to the initial brush sample (3.1 vs 24.1). PAF did not produce any change in methacholine-induced secretory responsiveness at any time. It appears that PAF possesses eosinophil chemotactic properties in the human nasal airway without altering the nasal secretory responsiveness. This confirms previous findings that the induction of nasal responsiveness is a more complex phenomenon than just the recruitment of eosinophils into the airway mucosa.

Eosinophils, secretory responsiveness and glucocorticoid-induced effects on the nasal mucosa during a weak pollen season

This study examined the seasonal effects on eosinophils and secretory responsiveness of the nasal mucosa in 22 patients with allergic rhinitis due to birch pollen (11 patients received placebo and 11 budesonide, 200 micrograms once daily in each nostril). The pollen counts during the study season were too low to produce a significant symptomatology. Hence, our findings demonstrate threshold alterations of the airway mucosa in allergic rhinitis and their inhibition by anti-inflammatory drug intervention. The patients were monitored for 8 weeks with daily recordings of pollen counts and symptom scores. Once every week a series of laboratory tests was carried out: the local eosinophil influx was determined using a Rhinobrush technique; the levels of eosinophil cationic protein (ECP) were analysed in nasal lavage fluids; and the secretory response to intranasal methacholine was measured. Treatments started after a 2-week run-in period. The proportion of eosinophils increased markedly in the placebo group and was elevated also during the last two study weeks when the pollen counts were practically nil. The secretory responsiveness to methacholine increased during the pollen season and returned to baseline towards the end of the study period. The topical glucocorticoid treatment reduced the proportion of eosinophils, the ECP levels, and the secretory response to methacholine compared to placebo. We conclude that the increased traffic and activity of eosinophils and less conspicuously the increased secretory responsiveness are expressions of the mucosal inflammation that precede the development of symptoms in seasonal allergic rhinitis.

Immunotherapy decreases antigen-induced eosinophil cell migration into the nasal cavity

We investigated the effect of immunotherapy (IT) on eosinophil (EOS) migration into the nasal cavity after nasal provocation with ragweed antigen and during seasonal exposure. In the first study, three groups of subjects participated: one group with no treatment (N = 19), one group with 10 months of IT, reaching maintenance at 2 micrograms of Amb a I (antigen E) (N = 15), and one group with 22 months of IT, reaching maintenance at 24 micrograms of Amb a I (N = 10). The percent of EOSs in nasal lavages performed during December before and 24 hours after nasal challenge with ragweed extract was determined. No significant difference between groups existed before challenge. The no treatment group demonstrated a significant increase in the percent of EOSs from 26% to 69.5% (p less than 0.008), whereas the treated groups demonstrated no significant change. In the second study, 45 patients were divided into four groups based on maintenance dose in micrograms of Amb a I and duration of treatment: (1) no treatment (N = 15), (2) 1 year at 2 micrograms (N = 13), (3) 2 years at 2 micrograms (N = 11), and (4) 3 years at 24 micrograms (N = 9). Nasal mucosal brushings were done during the ragweed season. A significantly smaller percentage of EOSs in 3-year IT-treated individuals was obtained compared to the control group (18 versus 8.4; p less than 0.04). The smaller dose of IT, regardless of duration, did not reveal a reduction compared to that in the no-treatment group.(ABSTRACT TRUNCATED AT 250 WORDS)

Allergen-induced changes in nasal secretory responsiveness and eosinophil granulocytes

The release of toxic granule proteins from the eosinophil granulocytes is generally believed to play a crucial part in the development of allergen-induced lesions of the barrier function leading to such clinical features of continuous allergic airway disease as oedema, hypersecretion, changes in responsiveness to specific and non-specific stimuli and, in the case of the lower airways, bronchoconstriction. In the upper airways, a nasal challenge/rechallenge model has proved useful in the study of the allergic inflammatory response in hay fever patients both in experimental settings and during natural pollen exposure. Repeated nasal lavage procedures and challenges with methacholine following an initial challenge with different doses of allergen or placebo were performed in 16 hay fever patients. Following an immediate allergic reaction, a statistically significant increase in the secretory response to methacholine was seen 30 min after challenge with the higher doses of allergen (p less than 0.01) but not after the lowest dose or placebo. An influx of eosinophil granulocytes was seen within 30-60 min of the allergen challenge regardless of the dose (p less than 0.01). The activation of these cells was measured by the increased levels of ECP (eosinophil cationic protein) in the nasal lavage fluid. No relationship was found between individual changes in eosinophils or levels of ECP and changes in the secretory response to methacholine or nasal symptoms. This lends further support to our previous observations that eosinophil granulocytes are not necessarily linked to allergen-induced changes in nasal secretory responsiveness.

Macrophages on the nasal mucosal surface in provoked and naturally occurring allergic rhinitis

Macrophages are the most common cell type residing in the lumen of the lower airways. However, very little is known about the presence and putative pathogenic implications of macrophages in the upper airways. Using specific immunohistochemical techniques, the presence of and changes in macrophage density were studied before and after allergen exposure in the laboratory and during natural allergen exposure of subjects with seasonal allergic rhinitis. The monoclonal antibody EBM 11 combined with the alkaline phosphatase-anti-alkaline phosphatase-technique was applied on cytospin-prepared slides. In the challenge experiment, 0.5 +/- 0.2% (mean +/- SEM; n = 10) of the total cell number were positive for the EBM 11 marker before challenge, thereby not differing from the controls (0.2 +/- 0.2%; mean +/- SEM; n = 3). Local allergen challenge induced an increase of these cells to a peak of 1.3 +/- 0.4% after 4 h (p less than 0.05). During seasonal exposure there was also a similar increase, from 0.7 +/- 0.2 to 1.3 +/- 0.3% (p less than 0.05; n = 11) in placebo-treated patients and from 0.7 +/- 0.2 to 1.6 +/- 0.4% (p less than 0.05; n = 11) in patients treated with topical glucocorticoids. There was, however, no direct relationship between nasal symptoms and number of macrophages present on the mucosal surface. The study indicates that macrophages are involved in the inflammatory processes of allergic rhinitis.

Effect of a single dose of a topical glucocorticoid and a cyclo-oxygenase inhibitor on allergen-induced changes in nasal reactivity

The inflammatory response of airway mucosa to allergen exposure is a complex phenomenon featuring symptoms, the influx of inflammatory cells, the release of mediators, and changes in local reactivity. These features and their pharmacological modifications can be successfully studied in nasal challenge models. We performed a nasal allergen challenge followed by a rechallenge with allergen 24 h later in order to monitor changes in specific reactivity due to the initial allergen challenge. Symptoms were monitored, as was the generation of TAME-esterase activity in nasal lavage fluids. Prior to each challenge a nasal brush specimen was taken. In a double blind, cross-over, double-dummy manner the patients were pretreated with placebo, a single dose of 200 micrograms of budesonide (topical corticosteroid) given 2 h prior to rechallenge with allergen or 600 mg ibuprofen (cyclooxygenase inhibitor) given per os t.i.d. to steady state starting 24 h prior to the initial allergen challenge. Treatment with ibuprofen induced a slightly lower composite symptom score (P less than 0.05) at the initial allergen challenge when compared with placebo. No differences were noted in the relevant TAME-esterase activities. The allergen challenge resulted in significantly increased proportions of eosinophils in the brush specimens 24 h after the initial allergen challenge (P less than 0.001) with no differences between the different treatment alternatives. At rechallenge there was a reduction in the symptoms of secretion and nasal blockage in both groups receiving active treatment compared with placebo (P less than 0.05), whereas the number of sneezes was not affected and no differences were noted in TAME-esterase activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Allergen-induced increase in nonspecific nasal reactivity is blocked by antihistamines without a clear-cut relationship to eosinophil influx

Antihistaminic compounds have been suggested to possess other properties besides H1-receptor antagonism. To evaluate whether two different antihistamines could inhibit local eosinophil infiltration and allergen-induced nonspecific nasal hyperreactivity, 15 subjects with seasonal allergic rhinitis participated in a double-blind, randomized, placebo-controlled study outside the pollen season. At steady-state levels of either 60 mg of terfenadine, twice daily, cetirizine, 10 mg once daily, or placebo, a nasal methacholine challenge was performed before and 24 hours after a nasal allergen challenge. The volume of the methacholine-induced nasal secretions was measured. The response to allergen was determined with a scoring technique. Cells from the nasal mucosal surface were harvested with the aid of a rhinobrush. Both antihistamines induced a similar (p less than 0.01) reduction in nasal symptoms after the allergen challenge compared with placebo. Both antihistamines inhibited the increased nonspecific nasal reactivity induced by methacholine 24 hours later (p less than 0.05). The allergen challenge induced an increase in surface eosinophils, which, however, appeared unaffected by any of the active treatments. Since histamine per se does not induce changes in nonspecific reactivity, we suggest that the antihistamines possess other properties besides being H1-receptor antagonists.

Changes in non-specific nasal reactivity and eosinophil influx and activation after allergen challenge

It has been suggested that the eosinophilic granulocyte plays a crucial role in the genesis of increased reactivity of the airways. In order to characterize changes in non-specific reactivity in the upper airways following a nasal allergen challenge further 16 subjects with strictly seasonal allergic rhinitis were studied. They were challenged with allergen outside the relevant pollen season and monitored at intervals for a period of 24 hr for nasal symptoms, changes in nasal reactivity, eosinophil influx and activation, and markers of inflammation. The same challenge sequence without an initial allergen challenge was used as a control. A symptom score technique was used to record nasal symptoms and methacholine challenges were used to monitor changes in non-specific reactivity. A nasal lavage was made prior to each methacholine challenge to monitor the influx of cells, specifically eosinophils, and to determine changes in the levels of eosinophil cationic protein (ECP) and TAME-esterase activity. Cells from the mucosal surface were also collected with a Rhinobrush prior to the allergen challenge as well as at the 24-hr follow up. The allergen challenge induced a five-fold increase in non-specific nasal reactivity, as measured by the methacholine challenges, at the 2-hr follow up from 0.051 ml +/- 0.012 (mean +/- s.e.m.) to 0.255 +/- 0.062 (P less than 0.01) and a significant increase was also noted at all observation points, whereas no increases could be observed in the control setting.(ABSTRACT TRUNCATED AT 250 WORDS)

Nasal mucosal response to repeated challenges with pollen allergen

In order to explore the dynamics of the cellular response of the airway mucosa to allergen exposure, controlled daily allergen challenges were performed for 7 days during the pollen-free winter months in nine patients with strictly seasonal allergic rhinitis caused by birch pollen allergen. Symptoms obtained after the challenge were related to morphologic changes within and on the surface of the nasal mucosa. Cell samples were obtained daily prior to challenge from the nasal mucosa using mucosal imprints on plastic strips, brush samplings from the nasal mucosa, and nasal lavage. For light microscopy, the cellular material obtained by brushing and nasal lavage were cytocentrifuged onto object slides. Histamine was measured in the cell pellets that were obtained using the lavage and brush procedures as well as in the lavage supernatant fluid. Four symptoms (sneezes, itching, secretion, and blockage) were recorded and expressed individually as well as in the form of a composite symptom score. Nasal blockage was measured using a nasal peak flow meter. The patients displayed an increase in nasal symptoms after the allergen challenge, which was further increased between Days 2 to 7 (p less than 0.05). The light microscopic evaluation of the lavage revealed an immediate increase in eosinophils from 2.3 to 13.1% and was maintained on the same level throughout the period of challenges. A similar increase was noted in the brush specimens, and a strong correlation was obtained between these two methods of sampling.(ABSTRACT TRUNCATED AT 250 WORDS)