Granulocyte/macrophage-colony stimulating factor in allergen-induced rhinitis: cellular localization, relation to tissue eosinophilia and influence of topical corticosteroid

BACKGROUND

Allergen-induced late nasal responses are associated with recruitment of T lymphocytes and eosinophils, and preferential messenger RNA (mRNA) expression of 'TH2-type' cytokines. We previously showed that topical steroid inhibited the late response and associated tissue eosinophilia. In this study we tested the hypothesis that granulocyte/macrophage-colony stimulating factor (GM-CSF) may contribute to late-responses and tissue eosinophilia and is inhibitable by topical corticosteroid.

METHODS

Nasal biopsies were taken before and 24 h after nasal allergen provocation following 6 weeks of treatment with either a nasal corticosteroid spray (fluticasone propionate) or a matched placebo nasal spray twice daily. Cryostat sections were processed by immunohistochemistry and in situ hybridization to assess cytokine mRNA expression for GM-CSF.

RESULTS

Increases in T lymphocytes and eosinophils were seen in the nasal mucosa after allergen challenge (p = 0.01) which were accompanied by a 5-fold increase in cells expressing mRNA for GM-CSF (p = 0.01). Double immunohistochemistry/in situ hybridization demonstrated that the majority of GM-CSF mRNA+ cells were co-localized to CD68+ (40%), or T cells (40%) with a lesser contribution from eosinophils (<20%). Topical steroid treatment was accompanied by a decrease in both the CD3+ and major basic protein (MBP+) cells expressing GM-CSF mRNA (p = 0.01) with a corresponding proportionate increase in the % of macrophages expressing GM-CSF.

CONCLUSIONS

The results indicate that after allergen provocation, eosinophils are recruited to the nasal mucosa and that, at least in part, this may be due to GM-CSF. Topical nasal corticosteroid inhibits late responses and the associated eosinophilia, possibly indirectly by decreasing GM-CSF from T lymphocytes or reducing autocrine production of GM-CSF from eosinophils.

Stem cell factor mRNA expression and production in human nasal epithelial cells: contribution to the accumulation of mast cells in the nasal epithelium of allergy

BACKGROUND

In allergic rhinitis, mast cells are increased in number in the epithelium of the nasal mucosa and play an important role in the immediate response. However, the mechanism of the accumulation is not known.

OBJECTIVE

The purpose of this study was to determine whether the nasal epithelial cells produce stem cell factor (SCF), the mast cell growth and chemoattractant factor, and contribute mast cell hyperplasia in the epithelium of allergic rhinitis.

METHODS

We have characterized the cellular localization of SCF using immunohistochemistry, reverse transcribed-PCR, and ELISA; compared SCF production of cultured epithelial cells between patients with allergic rhinitis and nonallergic subjects; and compared the SCF production with the number of mast cells and the histamine content in the nasal epithelial scrapings.

RESULTS

Immunohistochemically, SCF was identified in the nasal epithelium of the biopsy specimens and in cultured nasal epithelial cells. SCF mRNA was expressed by cultured nasal epithelial cells not only in patients with allergy but also in subjects with no allergy. However, the SCF/beta-actin mRNA ratio and SCF production in day 7 cultured epithelial cells was significantly higher in allergic than in nonallergic subjects (P =. 0424, P =.0085, respectively). SCF production from nasal scrapings in culture was strongly correlated with the number of mast cells (r = 0.506, P =.0023) and the histamine content (r = 0.480, P =.0040).

CONCLUSIONS

These findings demonstrate that nasal epithelial cells produce SCF and may be important in the attraction, proliferation, and activation of mast cells in allergic inflammation in the nose.

Nasal eosinophilia and IL-5 mRNA expression in seasonal allergic rhinitis induced by natural allergen exposure: effect of topical corticosteroids

BACKGROUND

Nasal allergen provocation in patients with allergic rhinitis leads to expression of the proeosinophilic cytokines IL-5 and GM-CSF and tissue eosinophilia.

OBJECTIVE

We sought to examine the effect of natural seasonal allergen exposure on IL-5 and GM-CSF mRNA expression and nasal eosinophilia and to evaluate the effects of topical corticosteroid therapy on these responses.

METHODS

Nasal biopsy specimens were collected from 46 grass pollen-sensitive patients with seasonal rhinitis before the grass pollen season. A second biopsy specimen was collected during the pollen season, by which time patients had received 6 weeks treatment with either fluticasone propionate (200 micro(g) twice daily) or placebo nasal spray.

RESULTS

Fluticasone treatment was clinically effective (P <.005). Patients receiving placebo, but not fluticasone, showed increased numbers of epithelial and submucosal EG2+ eosinophils (P <.005) and IL-5 and GM-CSF mRNA-expressing cells (P <.0001) during the pollen season. Colocalization experiments showed that greater than 80% of IL-5 mRNA-expressing cells were submucosal CD3+ T cells in both groups. The numbers of submucosal CD3+ T cells did not increase during the pollen season or decrease with fluticasone treatment. Fluticasone also inhibited IL-5 secretion by grass pollen-stimulated peripheral blood T cells from patients with seasonal rhinitis (n = 5, inhibitory concentration of 50% = 10(-9) to 10(-10) mol/L).

CONCLUSIONS

These results suggest that topical corticosteroids may reduce eosinophilia in seasonal rhinitis by inhibiting T cell IL-5 production.

Cells and cytokines in pollinosis

Pollinosis is a spontaneous model of allergic disease self limited in time. In order to evaluate immune response during pollen exposition cellular populations CD2, CD4, CD8, CD19, CD22, CD23, CD28, CD29, CD45RA, CD45RO have been studied before, during and after pollen season by flux cytometry. Simultaneous assays of soluble CD23 and cytokines IL-2, IL-4 and IL-2 soluble receptor have been done by an ELISA method. A decrease of CD23 PBC was observed during pollen season maintained afterwards without significant changes in sol CD23. The level of CD45RO memory cells decreased during pollen season with an opposed pattern for CD45RA naive cells. PBC expressing integrin chain CD29 were also decreased during the peak of pollen season. These results show that allergen exposition triggers a turnover of CD45 PBC, a decrease of low affinity IgE receptor CD23 in PBC and a consumption or binding of cells presenting the CD29 integrin chain. Cellular mechanisms are deeply implied in the immune response to pollens and cellular changes can be used as allergic inflammation markers in pollinosis.

Effects of orally inhaled budesonide in seasonal allergic rhinitis

It has previously been demonstrated that topical nasal treatment with glucocorticosteroids has significant effects on the bronchial airways. Less is known about effects on nasal disease by topical bronchial treatment with these drugs. The present study examined effects on nasal allergic disease of inhaled budesonide (avoiding nasal deposition of the drug). Patients with seasonal allergic rhinitis, but without asthma, were thus given inhalations of budesonide (600 microg b.i.d.) or placebo. The aim of the design was to allow the study of eosinophilic airway disease in a part of the airway other than the directly treated locus. Moderate to high birch pollen levels were recorded during the study season, and nasal symptoms were significantly increased in both treatment groups, although they were milder in patients receiving budesonide than in the placebo group (p<0.05). Nasal brush eosinophils and nasal lavage fluid levels of eosinophil cationic protein as well as blood eosinophils were increased during the season (p<0.05), but these increases were prevented by the inhaled budesonide. Nasal lavage fluid levels of alpha2-macroglobulin were particularly elevated in the placebo group but did not differ between patients receiving placebo and budesonide. Budesonide prevented the seasonal development of increased bronchoconstrictor responses to methacholine challenge (p<0.05). In conclusion, budesonide reduced the seasonal eosinophilia both in the circulation and in the nose along with an attenuation of seasonal nasal symptoms. Hence, at a daily dose of 600 microg b.i.d., known to cause no, or minimal, adverse effects, inhaled budesonide produces clinically significant anti-inflammatory effects in the entire airways, including the nasal mucosa, which is not exposed topically to the drug. We suggest that nasal and systemic anti-eosinophil actions are produced at commonly employed dose levels of orally inhaled budesonide.

Effect of slow-release theophylline on nasal antigen challenge in subjects with allergic rhinitis

It has been recognized recently that theophylline possesses anti-inflammatory effects that could be of clinical interest in patients with airway inflammatory diseases such as asthma and allergic rhinitis (AR). The aim of the present study was to explore the effect of theophylline on the nasal eosinophilic inflammatory response following allergen challenge in patients with AR. Fourteen subjects suffering from seasonal rhinitis with an early reaction after nasal allergen provocation were challenged outside the pollen season after pretreatment for 3 weeks with placebo or slow-release theophylline (Euphylong in a randomized double-blind, cross-over study. Nasal blocking index (NBI), nasal airway resistance and symptoms were recorded before, and 1 and 5 h after challenge; additionally, nasal lavage fluid was collected before, as well as 1 and 5 h after challenge. Eosinophil cationic protein (ECP) was measured in the lavage as well as the number of eosinophils before, and 1 h and 5 h after allergen challenge. After 3 weeks of treatment, baseline concentrations of ECP in nasal lavage amounted to 826+/-329 ng x L(-1) (placebo) and 936+/-351 ng x L(-1) (theophylline). The ECP levels did not increase during the early phase response. Five hours after challenge, ECP in the placebo group increased markedly (p<0.01), whereas no significant increase was observed during theophylline treatment. In parallel, the number of eosinophils in the nasal lavage fluid was lower during theophylline treatment. Additionally, theophylline therapy also significantly reduced the nasal symptoms and had some protective effect against nasal obstruction following allergen challenge. These results confirm the anti-inflammatory effects of theophylline and suggest that these effects may be of clinical benefit in patients with allergic rhinitis.

RANTES induces nasal mucosal inflammation rich in eosinophils, basophils, and lymphocytes in vivo

RANTES is a CC chemokine that causes chemotaxis of eosinophils, basophils, and lymphocytes in vitro. The objective of this study was to investigate the effect of RANTES on the influx of inflammatory cells into the nasal mucosa of 12 allergic patients. In the first phase, each patient was challenged with RANTES or diluent on two subsequent days. RANTES caused a significant (p < 0.05) influx of eosinophils as compared with the diluent. The number of eosinophils were 5,548 +/- 1,532/ml and 462 +/- 206/ml after RANTES and diluent challenge, respectively, at the peak of the response at 2 h. There was also a significant influx of metachromatic cells and lymphocytes, but not monocytes, neutrophils, or epithelial cells after RANTES challenge. In the second phase, the patients were first challenged with an allergen and 24 h later, challenged with RANTES or diluent. In the allergen-primed mucosa RANTES induced a significantly higher influx of eosinophils, basophils, and lymphocytes. Further, RANTES caused migration of monocytes and neutrophils, and shedding of epithelial cells. The influx of the inflammatory cells was associated with symptoms of rhinitis. We conclude that RANTES induces a clinically symptomatic inflammatory response in vivo by causing chemotaxis of eosinophils, basophils, and mononuclear cells.

Intranasal beclomethasone reduces allergen-induced symptoms and superficial mucosal eosinophilia without affecting submucosal inflammation

Previous investigations have suggested that nasal secretions, obtained by lavage or scraping, and the nasal submucosa, sampled by biopsy, are two distinct compartments. We investigated the effect of intranasal corticosteroids on antigen-induced eosinophil influx into both compartments. We performed a double-blind, placebo-controlled study in 15 patients with seasonal allergic rhinitis. Beclomethasone dipropionate, 84 microg twice a day, was delivered to one nostril while the other nostril received placebo for 1 wk. Subjects were then challenged with grass or ragweed extracts on each inferior turbinate. Nasal scrapings from both inferior turbinates were obtained before and 24 h after challenge, and bilateral inferior turbinate biopsies were obtained 24 h after challenge, with the subjects still receiving treatment. Intranasal steroids led to a significant reduction in sneezes and eosinophil influx in nasal secretions without affecting the number of eosinophils in the submucosa. Furthermore, intranasal steroids had no effect on the numbers of submucosal EG2+ (activated eosinophils) or CD25+ (IL-2-receptor-bearing) cells, nor did they decrease the endothelial expression of vascular cell adhesion molecule-1 (VCAM-1). These data show that pretreatment with intranasal steroids successfully inhibited the clinical response to allergen and reduced eosinophils in the superficial compartment of the nasal mucosa, but it had no effect on inflammation in the deeper compartment. This might be related to a different distribution of the active medication and antigen into the nasal mucosa or to a specific effect of the active medication on the epithelium resulting in inhibited migration of eosinophils across this layer.

Generation of clusters of free eosinophil granules (Cfegs) in seasonal allergic rhinitis

Generation of clusters of free eosinophil granules (Cfegs), through lysis of eosinophils, has recently been proposed as a major paradigm for ultimate activation of airway mucosal eosinophils. In the present study involving patients with seasonal allergic rhinitis, we have investigated whether generation of Cfegs in the nasal mucosa is a feature of allergic rhinitis. Nasal mucosal biopsies were obtained before and late in a birch-pollen season, and were subjected to histochemical staining of eosinophil peroxidase. In biopsies obtained before the pollen season, a few, intact eosinophils were observed, and Cfegs were scarce. In biopsies taken during the pollen season, the numbers of eosinophils were increased about 10-fold (P < 0.05) and the Cfegs about 25-fold (P < 0.05). We conclude that generation of Cfegs is a significant feature of seasonal allergic rhinitis and that this process represents the ultimate activation of mucosal eosinophils in this disease.

Loratadine-pseudoephedrine in children with allergic rhinitis, a controlled double-blind trial

AIMS

To conduct a randomized placebo controlled double-blind crossover trial in order to evaluate a loratadine-pseudoephedrine combination (L + PS) in children with seasonal allergic rhinitis.

METHODS

Forty children (15 males; 25 females), aged 3-15 years, were included in this study. They were randomized to receive L + PS (0.2 mg kg[-1] body weight-2.4 mg kg[-1] body weight respectively) or placebo (PLA) for 14 days. After 7 days of washout, patients were shifted to the other treatment for a further 14 days. Nasal symptoms (sneezing/itching, congestion, nasal dripping) and signs (turbinal swelling, retronasal drainage), rated on a scale ranging from: 1. absent to 5. very intense, and their sum or mean total symptom score (MTSS) were used as efficacy measurement.

RESULTS

Significant relief was observed; post-treatment MTSS difference and its percent change were respectively; L + PS = -4.29; 95% CI: -3.64 and -4.94 (27.8%), and PLA = -1.63; 95% CI: -0.95 and -2.31 (10.7%) (P < 0.001 baseline vs endpoint and between treatments). Furthermore, L + PS and PLA significantly modified symptoms, but only L + PS significantly modified signs. No clinical changes were observed during the trial; only one patient showed slight transient insomnia when receiving L + PS.

CONCLUSIONS

It is concluded that L + PS is useful and well tolerated in children with seasonal allergic rhinitis. However, elements such as placebo effect must be taken into account for planning future trials.

Local corticosteroid treatment: the effect on cells and cytokines in nasal allergic inflammation

Regular and prophylactic use of topical corticosteroids is a well tolerated and effective treatment for allergic rhinitis. The symptomatology of allergic rhinitis is considered to be the result of the accumulation and activation of infiltrating inflammatory cells, releasing mediators, and cytokines. Corticosteroids can suppress many stages of the allergic inflammatory process. This may explain their potent effect on allergic symptomatology. The reduction in cell numbers and probably also cytokines by local corticosteroid therapy differs from cell to cell. Some cells, such as antigen presenting (Langerhans) cells and eosinophils, are highly sensitive to corticosteroid treatment. Others, like T cells, are only significantly reduced in exaggerated situations, for instance after provocation with a high allergen dose or after treatment with a high dose of corticosteroids. Some cells, like macrophages, are not influenced at all.

[Cutaneous reactivity to foods among patients with allergic rhinoconjunctivitis]

Ocular allergy could be induced by food allergy or inhaled allergens. However there are few pediatric studies about it. Our objective was to know the frequency in children who have food allergy as cause of their ocular allergy. We perform a prospective and descriptive study in 50 patients within 6 to 16 years of age during June 1996 to January 1997. Skin prick tests to food allergens and inhalants, serum IgE levels by ELISA (enzyme immunoassay), nasal and conjunctival cytology were done. Not paired student T-test, Mann-Whitney U, and Kruskall-Wallis test were used for statistical analysis. We found mean of age 9.1 years +/- 2.5. Prick tests were positives to foods in 20%, 50% to inhalants and 30% to both. Food allergens seen more frequently were shellfish, tomato, rice, peanut and inhaled allergen Dermatophagoides pteronissinus. Serum IgE was elevated and ocular cytology was positive in food hypersensitivity group with significance difference (p = 0.023). In conclusion, we found a high frequency (50%) of food hypersensitivity in patients with allergic rhinoconjunctivitis.

A new model of experimental allergic rhinitis using Japanese cedar pollen in guinea pigs

In the majority of the models of experimental allergic rhinitis, antigen challenge has been performed by single topical instillation or perfusion with the solution. The present study was performed to establish a good model using Japanese cedar pollen, which is able to repeatedly induce allergy restricted to the upper airway. Guinea pigs sensitized with the pollen extracts were subjected to quantitative and repeated inhaling of the pollen with a devised apparatus. Following the respective challenges, the nasal cavity was washed with a new technique: Washing with physiologic saline was performed from one nostril to the other one, the latter of which was kept under slightly reduced pressure. When the animal was subjected to cedar pollen inhalation, almost all the pollens inhaled were located in the upper airway. At the 5th inhalation, nasal cavity lavage revealed that both albumin leakage and histamine release into the nasal cavity were increased at maximum levels in 1 hr (respectively 2 mg and 3 ng/animal); and at the same time, a considerable number of leukocytes, especially eosinophils, were found migrating into the nasal cavity for at least 10 hr. The present methods can permit various analyses of allergic rhinitis and the assessment of drugs without sacrificing the animal over the long term.

Olfactory dysfunction in allergic rhinitis is related to nasal eosinophilic inflammation

BACKGROUND

Olfactory dysfunction is a common finding in patients suffering from allergic rhinitis. However, little is known about the pathophysiology underlying this phenomenon and about the time course of hyposmia in seasonal allergy.

METHODS

A prospective controlled study was performed on 17 patients with allergic rhinitis to grass pollen in order to evaluate olfactory function in correlation to the duration of allergen exposition, symptoms, eosinophil cationic protein (ECP) in nasal secretions, and nasal volume flow (NVF). Olfactory function was evaluated preseasonally and on days 3, 7, 14, and 21 of the season using a modified Connecticut Chemosensory Clinical Research Center testing procedure for threshold, identification, and discrimination. Twelve volunteers without allergy served as controls.

RESULTS

Preseasonally, patients and controls performed equally in discrimination and identification testing, but not in threshold testing. No changes were found in the controls, but a significant decrease in threshold and identification from the 7th day of the season in patients with allergy was noted that was better correlated to ECP than to NVF. NVF was already maximally decreased from the 3rd intraseasonal day with no further changes. ECP increase became significant at day 14.

CONCLUSION

Patients with grass pollen allergy develop olfactory dysfunction during natural allergen exposure that might be related to allergic inflammatory mechanisms.

Eosinophils, mast cells, and basophils in induced sputum from patients with seasonal allergic rhinitis and perennial asthma: relationship to methacholine responsiveness

OBJECTIVES

We attempted to determine whether inflammation is present in induced sputum of patients with seasonal allergic rhinitis (AR) as compared with those with perennial asthma (AS) and examined its relationship with bronchial responsiveness to methacholine.

METHODS

Sputum was induced in 30 patients with seasonal rhinitis in response to grass pollens only and in 15 patients with stable, asymptomatic asthma. The AR group was divided according to methacholine PD20 value: the AR- group (n = 15) had a methacholine PD20 greater than 24 micromol; the AR+ group (n = 15) had a methacholine PD20 ranging between 2.2 and 19.6 micromol. In the AS group, methacholine PD20 ranged between 0.42 and 2.6 micromol. The percentage of eosinophils and metachromatic cells (alcian blue-positive) was assessed in sputum by light microscopy. Tryptase-positive cells and EG2+ cells were identified by immunocytochemistry with the mouse anti-human mast cell-tryptase monoclonal antibody and the monoclonal anti-eosinophil cationic protein antibody.

RESULTS

We found that the number of eosinophils in the AS group was greater than that in the AR+ group (p < 0.05) and in the AR- group (p < 0.01). Moreover, the eosinophil count was lower in the AR- group compared with the AR+ group (p < 0.05). Similarly, the number of EG2+ cells was greater in the AS group than in the AR group (p < 0.02) and the AR- group (p < 0.05). Moreover, the EG2+ cell count was lower in the AR- group than in the AR+ group (p < 0.05). The number of mast cells and basophils in the AS group was greater than that in the AR group (p < 0.05 and p < 0.01, respectively). Mast cells in sputum were tryptase-positive. Basophils were present in sputum from 23% of patients with AR and 53% of patients with asthma. There was a significant correlation between methacholine PD20 and eosinophils (p < 0.005) and mast cells (p < 0.02) but not with basophils in those patients showing a measurable methacholine PD20 (AR+ and AS groups).

CONCLUSIONS

Inflammatory cells are present not only in the airways of patients with asthma but also in airways of patients with seasonal AR, even outside natural exposure. Moreover, we provide evidence for the presence of basophils in sputum of patients with asthma even during clinical remission. The presence of bronchial responsiveness is associated with an increase in the number of eosinophils and metachromatic cells. Our findings are consistent with the hypothesis that eosinophils, as well as mast cells, contribute to bronchial responsiveness not only in AS but also in seasonal AR.

Preferential infiltration by activated eosinophils in allergic sinusitis

Although Type I allergy is a trigger for provoking chronic inflammation, whether allergic sinusitis (AS) can be distinguished from sinusitis due to chronic infection is still debated. This study was performed to characterize inflammatory cells in AS and to determine whether patients with AS differ from patients with chronic suppurative sinusitis (CSS). 5 patients with AS and 10 patients with CSS were investigated. Cellular infiltration was studied using immunohistochemistry with monoclonal antibodies using CD3, CD4, CD8, CD25, major basic protein (BMK13), eosinophil cationic protein (EG2), neutrophil elastase, and tryptase. There were no differences in CD3+, CD4+, CD25+, and tryptase+ cells between the groups. Whereas the total number of eosinophils (BMK13+) also did not significantly differ, the number of activated eosinophils (EG2+) was significantly higher (P < 0.05) in patients with AS. Furthermore, a statistically significant increase in the percentage of activated eosinophils to total eosinophils (P < 0.05) was observed in patients with AS. In contrast, the number of neutrophil elastase+ cells was significantly higher (P < 0.05) in patients with CSS. These results suggest that patients with AS can be distinguished immunohistochemically from patients with CSS, with AS being distinguished by activated eosinophil infiltration.

[Influence of intercellular adhesion molecule-1 transcription on nasal epithelial cell by airborne allergenic pollens]

Eleven patients with Artemisia allergic rhinitis were evaluated. Among them 8 were studied during pollen season and 3 out of pollen season. Intercellular adhesion molecule-1(ICAM-1) was detected on nasal epithelial cells by reverse transcription polymerase chain reaction (RT-PCR). The results showed that ICAM-1 was detectable from all samples in the pollen season. However, during off-pollen season 2 of the 3 samples were negative, 1 was positive (who was also positive to house dust). It is suggested that ICAM-1 is detectable on nasal epithelial cells during exposure to specific allergen.

Endoscopic scoring system in patients with allergic rhinitis

Visual inspection of the airways in patients with chronic bronchitis and asthma by fiberoptic bronchoscopy and the relation of these findings to bronchoalveolar lavage (BAL) fluid analysis or some clinical parameters have been reported previously. In this study, we have attempted to assess and grade airway inflammation in allergic rhinitis patients (ARP) by fiberoptic bronchoscopy. During the procedure, BAL was obtained and visual inspection of airways done by the method used by Thompson et al. Ten ARP with bronchial hyperreactivity (BHR) (Group 1), 10 ARP without BHR (Group 2) and 2 nonatopic, healthy subjects (Control Group) were studied. The fluid recovery and differential cell concentration were similar in the three groups. The inflammatory scores were 11.0 +/- 7.0, 13.8 +/- 6.9, 15.0 +/- 4.2 in group 1, group 2 and control group, respectively, without showing any significant differences between the groups. There was no correlation between the inflammatory score and PC20 to methacholine. This indicates that BHR in ARP will need explanations other than the inflammation within airways.

[Transmission electron microscopic study on eosinophil degranulation in nasal mucosa in allergic rhinitis]

To observe the ultrastructure of eosinophil (EOS) degranulation in nasal mucosa in allergic rhinitis, nasal mucosa biopsies from patients with perennial allergic rhinitis (PAR, n = 13) pollinosis (PS, n = 9) subjects and normal controls (n = 3) were processed and the ultrastructure changes of EOS degranulation were examined under transmission electron microscope and routine histopathological observation. The ultrastructure of EOS degranulation in nasal mucosa collected from PAR and PS patients in their remission period differed from that in their attacking period, though there was no distinct differences in the distribution patterns of EOS. Increased cell membrane projections, eminent cytoplasm vacuolization, inconsistent density of granules with its crystalloid being lost, plus tissue edema and damage of collagen fibers in adjacent areas of degranulating EOS were among the most important ultrastructural changes of EOS in attacking period. The interrelations of EOS, mast cells (MC) and T-lymphocytes play important roles in the pathogenesis of allergic rhinitis.

Olfactory threshold after nasal allergen challenge

Olfactory threshold was investigated in patients with verified allergic rhinitis to birch pollen. In 20 patients the olfactory threshold was measured before and after challenge with topically applied birch pollen allergen during a non-symptomatic period. After provocation a statistically significant impaired detection sensitivity was found. The change in olfactory threshold was correlated with the measured amount of nasal secretions but not with subjectively or objectively registered nasal obstruction. A pronounced allergic reaction after allergen challenge is accompanied by an elevated olfactory threshold.

A comparison of cytokine release from epithelial cells cultured from nasal biopsy specimens of atopic patients with and without rhinitis and nonatopic subjects without rhinitis

BACKGROUND

Recent studies have suggested that airway epithelial cells of atopic and nonatopic individuals may differ in their ability to produce proinflammatory cytokines.

METHODS

We have cultured human nasal epithelial cells (NECs) as confluent explant cultures from nasal biopsy specimens of well-characterized nonatopic normal volunteers without rhinitis (n = 8), atopic volunteers without rhinitis (n = 9), and atopic patient volunteers with rhinitis (n = 10) and measured the amounts of IL-1 beta, IL-8, granulocyte-macrophage colony-stimulating factor, tumor necrosis factor-alpha, and RANTES released spontaneously into the culture medium by these cells in vitro. NECs from patients with allergic rhinitis were cultured from biopsy specimens obtained on two different occasions, during and after the pollen season.

RESULTS

In general, NECs from atopic individuals released significantly greater amounts of IL-1 beta, IL-8, granulocyte-macrophage colony-stimulating factor, tumor necrosis factor-alpha, and RANTES than NECs from nonatopic individuals. IL-8 was released in greatest quantity and IL-1 beta in lowest quantity, regardless of whether the NECs were derived from atopic or nonatopic volunteers. Of the atopic individuals, NECs of atopic patients with rhinitis naturally exposed to pollen released greater quantities of all these cytokines, compared with NECs of atopic patients with rhinitis and atopic patients without rhinitis who were not exposed to allergen.

CONCLUSIONS

These results suggest that NECs of atopic individuals, who are genetically predisposed to upper airway disease, release increased amounts of proinflammatory cytokines and that natural exposure to allergen enhances the release of these cytokines, exacerbating the symptoms of allergic disease.

Budesonide aqueous nasal spray and pressurized metered dose inhaler in the treatment of adult patients with seasonal allergic rhinitis

Budesonide, a topical corticosteroid used in the treatment of seasonal allergic rhinitis, can be administered to the nose as an aerosol via a pressurized metered dose inhaler (pMDI) or as a metered nasal pump spray. Studies have shown that about 64% (256 micrograms) of a nominal dose of 400 micrograms budesonide pMDI preparation is delivered to the patient compared with 100% of the nominal dose of the pump spray. The present study was undertaken to assess the efficacy and safety of budesonide delivered via a nasal pMDI twice daily (Rhinocort pMDI, at 400 micrograms/day) with an aqueous suspension of budesonide delivered via a metered nasal pump spray once daily (Rhinocort Aqua, at 256 micrograms/day or 400 micrograms/day). The multicenter, double-blind, randomized, placebo-controlled, parallel-group study was conducted in 318 patients (154 men, 164 women; aged 12-67 years) with ragweed-induced seasonal allergic rhinitis. A 1-week baseline period was followed by a 3-week treatment. Nasal symptoms were recorded by the patients, adverse events were noted, an overall evaluation of treatment efficacy was made, and urine cortisol and creatinine levels were measured. Substantial or total control of symptoms was achieved in 83.8% of patients treated with 256 micrograms of aqueous budesonide, 76.3% with 400 micrograms of aqueous budesonide, and 80.8% with 400 micrograms of budesonide pMDI; these were all significantly different (p < 0.001) compared with placebo (23.4% of patients). There were no significant differences in the 24-hour urine cortisol levels between the groups and there were few, infrequent adverse events, similar between the groups and resolved completely on discontinuation of treatment. It was concluded that budesonide, given once daily as 256 micrograms or 400 micrograms in an aqueous suspension or twice daily as 400 micrograms in a pMDI provides good alleviation of the symptoms of seasonal allergic rhinitis with no significant risk of suppression of urine cortisol.

Lower airways remodeling in nonasthmatic subjects with allergic rhinitis

We analyzed by immunohistochemistry the distribution of types I, II, III, IV, V, and VII collagens, laminin, and fibronectin in the bronchial biopsy specimens of nonasthmatic subjects with seasonal allergic rhinitis (n = 8) and compared these results with those found in mild stable allergic asthmatics (n = 6) and normal controls (n = 5). The content of type I and III collagens was increased in rhinitic subjects compared with controls. These collagens were focally deposited in the reticular basement membrane area. Three subjects with allergic rhinitis had no fibronectin deposition in their basement membrane, as in controls, whereas the other five had a focal fibronectin deposition. In asthmatic patients, type I and III collagens and fibronectin were more abundant and more uniformly distributed underneath the basement membrane than they were in rhinitic subjects. Expression of type II, IV, V, and VII collagens and laminin were similar in the three groups. Electron microscopic and immunohistochemical analyses of bronchial mucosa showed a network of myofibroblasts beneath the epithelium in rhinitis as in asthma subjects. These data show that the irregularly distributed subepithelial fibrosis observed in subjects with allergic rhinitis results from the deposition of type I and III collagens and fibronectin, probably produced by bronchial myofibroblasts. These results suggest the presence of an active structural remodeling in the lower airways of allergic rhinitic subjects that is similar in nature to that seen in asthma, although less marked.

Quantitative cytology of nasal secretions and scrapings in Japanese cedar pollinosis patients

To explore the dynamics of the cellular response to natural allergen exposure, the authors of this study performed quantitative cytology in both the nasal secretions and nasal scrapings of 16 normal control subjects and 23 Japanese cedar pollinosis patients before and during the pollen season. In nasal scrapings, the number of metachromatic cells increased significantly during the pollen season, although there was no significant difference between the normal subjects and the preseason pollinosis patients. The cell differential count in the patients with pollinosis showed that lymphocytes were predominant in scrapings; however, the majority of inflammatory cells in the nasal secretions were neutrophils before the season and eosinophils during the season. The study findings suggest that the appearance of metachromatic cells in nasal scrapings is specific to the pollen exposure and that the cytology in nasal secretions is significantly different from that in nasal scrapings.

Effect of isolation protocol on eosinophil function: Percoll gradients versus immunomagnetic beads

Studies of in vitro eosinophil function are dependent on efficient and reliable methods of cell isolation. Protocols using Percoll or metrizamide density gradients have been of limited use in isolating peripheral blood eosinophils in sufficient numbers and purity from subjects with normal or only slightly elevated eosinophil counts, thereby restricting comparative studies to preparations from hypereosinophilic subjects. Recently, a method utilizing negative selection by anti-CD16 coated magnetic beads has greatly improved eosinophil isolation by dramatically increased yields and purity. However, little is known as to the differential effect of various isolation methods on the functional activity of eosinophils. In this study, eosinophils were isolated by either discontinuous multiple density Percoll gradients or anti-CD16-coated magnetic beads: several functional activities were then compared using cells obtained by the two methods of isolation. Compared with Percoll isolated eosinophils, anti-CD16 bead separated eosinophils had significantly increased baseline and stimulated LTC4 production, spontaneous O2- generation, and expression of specific cell surface markers. No significant difference was observed in the cells' in vitro survival and adhesion. Such differences may be due to the isolation of eosinophils of all densities by anti-CD16 beads, or the effect of neutrophils interacting with the beads to release eosinophil agonists or primers. Alternatively, the Percoll gradient method with the eosinophils' exposure to dextran and Ficoll-Hypaque may affect subsequent cell function. Therefore, comparison of eosinophil function between cells isolated by different protocols must be considered before concluding which is the true measure of in vivo cell function.