Effect of topical corticosteroids on seasonally induced increases in nasal mast cells

The role of nasal corticosteroids in the treatment of rhinitis

Intranasal corticosteroids (INSs) are the first choice for rhinitis pharmacotherapy. This preference is because of their broad range of actions that result in reductions of proinflammatory mediators, cytokines, and cells. Over the past 30 years, INSs have been modified to improve their pharmacodynamic, pharmacokinetic, and delivery system properties, with attention to improving characteristics such as receptor binding affinity, lipophilicity, low systemic bioavailability, and patient preference. Clinically, they have been shown to be the most effective class of nasal medications for treating allergic rhinitis and nonallergic rhinopathy, with no clear evidence that any specific INS is superior to others.

Mechanisms of immunotherapy: a historical perspective

OBJECTIVE

To provide a historical review of mechanisms proposed during the last century to explain the efficacy of immunotherapy.

DATA SOURCES

We retrieved review articles and original research from MEDLINE, OVID, and PubMed that addressed our topic of interest.

STUDY SELECTION

Articles were selected for their relevance to immunotherapy and mechanisms.

RESULTS

Early studies focused on the production of blocking antibodies induced by immunotherapy, with mechanistic explanations aimed at understanding a relationship between blocking antibodies and clinical response. This was followed by a period when the effects of immunotherapy on levels and function of effector cells in the allergic response were studied. Aiding in characterization of this response was the discovery of IgE and its role in allergic sensitization, which brought a renewed focus on the antibody-mediated effects of immunotherapy. In an attempt to create a unifying hypothesis to explain humoral and cellular mechanisms of immunotherapy, recent approaches have been focused on the role of the T cell and, specifically, regulatory T cells.

CONCLUSIONS

Although the clinical practice of immunotherapy has been refined since its introduction 100 years ago, our understanding of the mechanisms that underlie this success has awaited discoveries in basic immunology.

The treatment of vasomotor rhinitis with intranasal corticosteroids

Objective

Intranasal steroids (INS) are firmly established as the therapy for choice for allergic rhinitis, but their role in vasomotor rhinitis (VMR) is not fully characterized. This review examines the potential mechanisms of action and reported efficacy of INS in patients with VMR.

Results

INS, through intracellular activation of the glucocorticoid receptor, down-regulate the recruitment and activation of inflammatory cells (T-lymphocytes, eosinophils, mast cells, basophils, neutrophils, macrophages), increase degradation of neuropeptides, and reduce epithelial cell activity, vascular permeability, and chemokine secretion. It is likely that more than vasoconstriction is responsible for the clinical effects of INS.

Eight INS can be prescribed for rhinitis in the US; only 4 have been studied for VMR. Seventy-four percent of patients treated with beclomethasone dipropionate considered themselves symptom-free or greatly improved versus 31% with placebo. Budesonide significantly reduced rhinitis symptoms and methacholine-induced nasal secretions compared with placebo. Fluticasone propionate compared with placebo provided significantly greater relief from nasal obstruction; computed tomographic scans showed significant reductions in the mucosal area of the lower turbinates. Mometasone furoate produced numerically better rhinitis symptom scores and, when discontinued, lower relapse rates than placebo.

Conclusion

Data supports INS as beneficial pharmacotherapy for VMR.

Clinical benefits of combination treatment with mometasone furoate nasal spray and loratadine vs monotherapy with mometasone furoate in the treatment of seasonal allergic rhinitis

BACKGROUND

Intranasal corticosteroids and nonsedating antihistamines are the drug classes most often prescribed to treat allergic rhinitis (AR). Treatment guidelines recommend a combination of these agents for moderate-to-severe AR. However, clinical studies have found that combining an antihistamine with an intranasal corticosteroid provides few or no advantages over monotherapy with an intranasal corticosteroid.

OBJECTIVE

To compare the efficacy of mometasone furoate nasal spray (NS) plus loratadine with that of monotherapy with the individual agents in patients 12 years and older with at least a 2-year history of seasonal AR.

METHODS

In a multicenter, randomized, double-blind, parallel-group, placebo-controlled clinical study, 702 patients were randomized to receive mometasone furoate NS, 200 microg, plus loratadine, 10 mg (n = 169); mometasone furoate NS, 200 microg (n = 176); loratadine, 10 mg (n = 181); or placebo (n = 176) once daily for 15 days. Primary efficacy variables were total nasal symptom score (TNSS) and total symptom score (TSS) as recorded on diary cards.

RESULTS

No statistically significant differences were observed between mometasone furoate NS plus loratadine and mometasone furoate NS monotherapy for the primary efficacy variables. For TNSS and TSS, all 3 active drug therapies were more effective than placebo (P < or = .02). Both mometasone furoate NS treatment regimens were more effective than loratadine or placebo for TNSS (P < .01 for both) and TSS (P < or = .03 for both), whereas loratadine was more effective than placebo for TNSS only (P = .02).

CONCLUSIONS

Combination therapy with mometasone furoate NS and loratadine provided benefits similar to monotherapy with mometasone furoate NS for the symptoms of seasonal AR. Therefore, mometasone furoate NS monotherapy was shown to be an effective treatment for seasonal AR.

Topical glucocorticosteroids in rhinitis: mode of action

The introduction of nasal glucocorticosteroids, more than 30 years ago, represents the most important therapeutic progress in rhinitis management since the introduction of the first generation of antihistamines. Our knowledge of the mode of action of glucocorticosteroids in the nose has improved as the airway mucous membrane of the nose is easily accessible for investigation. However, the exact mechanism behind the marked clinical effect remains unclear. The present article presents some of the important effects of topical glucocorticosteroids on pathophysiological events in the nasal mucosa.

Comparison of nasal immunohistology in patients with seasonal rhinoconjunctivitis treated with topical steroids or specific allergen immunotherapy

BACKGROUND

Specific allergen immunotherapy (SIT) and nasal steroids (NS) are considered effective anti-inflammatory treatments for allergic rhinitis, although their mechanism of action differs.

OBJECTIVE

The aim of this study was to examine the effect of treatment with NS and SIT on different populations of inflammatory cells in the nasal mucosa and to compare cell numbers before and during the birch pollen season in patients with seasonal allergic rhinitis.

METHODS

In a randomized, double-blind, double dummy comparative study, 41 patients with seasonal rhinoconjunctivitis were treated with birch SIT or NS (budesonide 400 microg daily). Treatment with NS started before the birch pollen season and at the same time SIT-treated patients reached the maintenance dose. Nasal biopsies for immunohistochemistry were obtained before the season and start of the treatments and at the peak of the pollen season during treatment.

RESULTS

Symptoms of rhinoconjunctivitis increased significantly in both groups during the pollen season but less in the NS-treated group and the difference between the treatment groups was significant at the end of the season (P = 0.03). Immunohistochemistry of nasal biopsies from NS-treated patients showed significantly fewer CD1a+, IgE+ and Fc epsilonRI+ cells during the season compared with preseason (P = 0.02, P = 0.001 and P = 0.0004, respectively) and with seasonal values of the SIT-treated group (P = 0.002, P = 0.002 and P = 0.0004 respectively).

CONCLUSION

Treatment with NS but not SIT decreased the numbers of CD1a+, IgE+ and Fc epsilonRI+ cells during the birch pollen season. Our data indicate that treatment with NS has a broader anti-inflammatory range than SIT.

Comparison of intranasal corticosteroids and antihistamines in allergic rhinitis: a review of randomized, controlled trials

For several years there has been discussion of whether first-line pharmacological treatment of allergic rhinitis should be antihistamines or intranasal corticosteroids. No well documented, clinically relevant differences seem to exist for individual nonsedating antihistamines in the treatment of allergic rhinitis. Likewise, the current body of literature does not seem to favor any specific intranasal corticosteroid. When comparing efficacy of antihistamines and intranasal corticosteroids in allergic rhinitis, present data favor intranasal corticosteroids. Interestingly, data do not support antihistamines as superior in treating conjunctivitis associated with allergic rhinitis. Safety data from comparative studies in allergic rhinitis do not indicate differences between antihistamines and intranasal corticosteroids. Combining antihistamines and intranasal corticosteroids in the treatment of allergic rhinitis does not provide additional beneficial effects to intranasal corticosteroids alone. Considering present data, intranasal corticosteroids seem to offer superior relief in allergic rhinitis, when compared with antihistamines.

Comparison of the clinical efficacy and tolerability of olopatadine hydrochloride 0.1% ophthalmic solution and loteprednol etabonate 0.2% ophthalmic suspension in the conjunctival allergen challenge model

BACKGROUND

Olopatadine hydrochloride 0.1% ophthalmic solution and loteprednol etabonate 0.2% ophthalmic suspension are topical antiallergic agents indicated for treatment of the signs and symptoms of allergic conjunctivitis and seasonal allergic conjunctivitis (SAC), respectively.

OBJECTIVE

The purpose of this study was to compare the efficacy and tolerability of olopatadine, loteprednol, and placebo in inhibiting the early-phase allergic reaction (within 30 minutes) after conjunctival allergen challenge (CAC).

METHODS

This was a single-center, randomized, double-masked, parallel-controlled CAC study. It consisted of 3 visits, with CAC performed at visit 1, confirmation and randomization at visit 2, and evaluation of the treatments at visit 3. Subjects with a history of allergic conjunctivitis were randomized to receive olopatadine, loteprednol, or placebo in a 2:2:1 ratio. Because loteprednol requires a loading period to achieve maximum efficacy, subjects assigned to this treatment received loteprednol QID bilaterally for a 14-day period; the olopatadine and placebo groups received placebo QID bilaterally during this period. At the evaluation visit, subjects received 1 drop of the assigned treatment in each eye. Fifteen minutes later, they were challenged with allergen. Subjects evaluated itching at 3, 5, and 10 minutes after challenge using a standardized 5-point scale; the investigator evaluated redness at 10, 15, and 20 minutes after challenge. Intraocular pressure (IOP) was measured at baseline and after the 14-day loading period. Nonparametric analyses were performed on the change from visit 2 to visit 3 in mean itching and redness scores for each time point, and on the change in mean IOP from visit 1 to visit 3.

RESULTS

Fifty subjects (86% white; 42% male, 58% female; age range, 21-71 years) were enrolled and completed the study (20 olopatadine, 20 loteprednol, 10 placebo). The allergens to which subjects reacted were ragweed pollen (40%), cat hair or dander (30%), grass pollen (24%), and tree pollen (6%). The difference in inhibition of itching and redness was clinically significant (> or =1 unit difference) and statistically significant (P < 0.05) in favor of olopatadine compared with loteprednol at all 3 time points. The loteprednol group had a statistically significant increase in IOP after 2 weeks of treatment (P < 0.001).

CONCLUSION

In the population studied, olopatadine was more efficacious than loteprednol in reducing the acute signs and symptoms of SAC during the early phase of the ocular allergic reaction and appeared to be better tolerated.

Intranasal corticosteroids for allergic rhinitis: superior relief?

Whether first-line pharmacological treatment of allergic rhinitis should be antihistamines or intranasal corticosteroids has been discussed for several years. First-generation antihistamines are rarely used in the treatment of allergic rhinitis, mainly because of sedative and anticholinergic adverse effects. On the basis of clinical evidence of efficacy, no second-generation antihistamine seems preferable to another. Similarly, comparisons of topical and oral antihistamines have been unable to demonstrate superior efficacy for one method of administration over the other. Current data documents no striking differences in efficacy and safety parameters between intranasal corticosteroids. When the efficacy of antihistamines and intranasal corticosteroids are compared in patients with allergic rhinitis, present data favours intranasal corticosteroids. Interestingly, data do not show antihistamines as superior for the treatment of conjunctivitis. Safety data from comparative studies in patients with allergic rhinitis do not indicate differences between antihistamines and intranasal corticosteroids. Combining antihistamines and intranasal corticosteroids in the treatment of allergic rhinitis does not provide any additional effect to intranasal corticosteroids alone. On the basis of current data, intranasal corticosteroids seem to offer superior relief in allergic rhinitis than antihistamines.

A double-blinded, comparative study of the effects of short preseason specific immunotherapy and topical steroids in patients with allergic rhinoconjunctivitis and asthma

BACKGROUND

Both specific immunotherapy (SIT) and nasal steroid (NS) have been shown to effectively reduce symptoms of allergic rhinitis. Although a number of investigators have convincingly shown anti-inflammatory effects of both treatments in separate studies, few comparative studies have been performed.

OBJECTIVE

The purpose of this study was to compare the effects of preseason SIT with a standardized allergen extract and NS in seasonal allergic disease (rhinoconjunctivitis and asthma).

METHODS

We examined 41 patients allergic to birch pollen, 21 with rhinoconjunctivitis and 20 with both rhinoconjunctivitis and asthma; they were treated in a randomized, double-blinded comparative study with birch SIT and NS (budesonide 400 microg daily). Bronchial hyperresponsiveness was measured before and during the season. Changes in eosinophil number, eosinophil cationic protein, and eosinophil chemotactic activity (ECA) in peripheral blood were investigated.

RESULTS

Symptoms of rhinoconjunctivitis increased significantly less in the NS-treated patients than in the SIT-treated patients during the final 2 weeks of the season (P = .03 and P = .04, respectively). Seasonal peak expiratory flow values decreased significantly only in the NS-treated patients (P = .01). In the NS-treated patients, bronchial hyperresponsiveness increased significantly during the season (P = .0001); however, SIT treatment prevented seasonal PC(20) increase in the asthmatic patients. Measurement of blood eosinophils, eosinophil cationic protein, and eosinophil chemotactic activity demonstrated significant seasonal increase only in the NS-treated asthmatic patients.

CONCLUSION

Treatment with NS was more effective than short-course preseason SIT in reducing symptoms of rhinoconjunctivitis; however, the 2 therapies were equivalent in terms of the need for rescue medication. SIT prevented seasonal increase in bronchial hyperresponsiveness, eosinophil number, eosinophil cationic protein, and eosinophil chemotactic activity only in asthmatic patients. The mechanisms underlying bronchial hyperresponsiveness developing during allergen exposure in rhinitis might be different from those operating in asthma.

Mode of action of intranasal corticosteroids

The mode of action of intranasal corticosteroids (INCS) is complex. It is not known whether INCS penetrate the nasal mucosa or act on target cells; however, their low systemic activity supports the concept of local action on nasal mucosa. This local effect can nonetheless influence a variety of inflammatory cells and their mediators such as epithelial cells, lymphocytes, basophils, mast cells, and Langerhans cells. Corticosteroid-induced inhibition of immunoglobulin E-dependent release of histamine is a possible but unproven mode of action. Epithelial cells are an important target for corticosteroids, and INCS concentration is high at the epithelial surface. INCS may combine with the corticosteroid receptors in epithelial cells, which are then expelled into the airway lumen together with the dead epithelial cells or migrating inflammatory cells. A reduced influx of mediator cells may explain some of the effects of INCS on rhinitis symptoms, but it cannot explain all of the effects because INCS also reduce the early-phase sneezing and rhinorrhea after an allergen challenge outside the pollen season. In this situation, the number of surface mast cells/basophils is very low, as it is in the absence of allergic rhinitis. The mechanism by which INCS treatment of allergic rhinitis reduces itching, sneezing, and rhinorrhea, the characteristic symptoms of an early-phase response involving mast cell release of histamine, remains to be determined. Studies should be conducted to characterize the broad range of mechanisms by which INCS produce their therapeutic effects in allergic rhinitis.

Impact of allergic rhinitis treatment on quality of life

Allergic rhinitis is a chronic inflammatory disorder of the nasal passages. It affects approximately 20% of the population, is a significant health and economic burden, and severely impairs quality of life. Two main instruments, Medical Outcomes Study 36-Item Short Form health survey (SF-36) and Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) have been used to assess quality of life in patients with allergic rhinitis. Antihistamines, corticosteroids, anticholinergic agents, decongestants, cromoglycates, and immunotherapy are used to treat patients with allergic rhinitis. Of these, antihistamines and intranasal corticosteroids are the most efficacious and frequently utilised medications. Studies have demonstrated improvements in quality of life with both of these medications in patients with allergic rhinitis.

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.

Use of nasal steroids in managing allergic rhinitis

Intranasal steroids are highly effective drugs for treating patients with allergic rhinitis. First-line use of intranasal steroids is becoming increasingly common, and intranasal steroids can be used alone or in combination with other therapies to achieve optimal improvement in rhinitis symptoms. The major adverse effect of intranasal steroids is local irritation. This article reviews the mechanism of action of corticosteroids, the effects of intranasal steroids on chemical mediators of inflammation, and the risks and benefits associated with their use.

Demonstration of mast-cell chemotactic activity in nasal lavage fluid: characterization of one chemotaxin as c-kit ligand, stem cell factor

Mast cells are known to accumulate in tissue during allergic inflammation. However, the chemotaxins responsible are undefined. Using a modified Boyden chamber and the human mast-cell line HMC-1, we first identified mast-cell chemotactic activity in nasal lavage fluid collected before the pollen season after allergen provocation of allergic patients (n=29) (mean migratory response compared to medium control was 121%, range 85-198%). Mast-cell chemotactic activity was also detected in lavage fluid collected after allergen provocation at the end of a Swedish birch-pollen season from three different treatment groups: topical steroid treatment with budesonide; the topical antihistamine, levocabastine; and placebo. There was no significant difference in mast-cell chemotactic activity between nasal lavage fluid collected from the placebo group (mean=102%), the budesonide-treated group (mean=114%), or the levocabastine group (mean=125%). Stem cell factor (SCF), a known mast-cell chemotaxin, was present in the nasal lavage fluids from all three groups, and correlated with the mast-cell chemotactic activity (r=0.67, P<0.01). The mast-cell chemotactic activity was inhibited (range 5-100%) in some, but not all, nasal lavage fluids by a polyclonal antibody directed against SCF. This report describes the presence of mast-cell chemotactic activity in nasal lavage fluid during an allergic reaction. These findings show that SCF may play a pivotal role in the recruitment of mast cells in allergic rhinitis.

Immunologic changes associated with allergen immunotherapy

Specific allergen injection immunotherapy is highly effective in selected patients with IgE-mediated disease, including respiratory allergy and venom anaphylaxis. Research in this area provides insight into the immunologic basis of allergic disease and may assist in the development of more highly targeted treatment. Immunotherapy reduces immediate allergen-induced symptoms and concentrations of inflammatory mediators, including histamine and prostaglandin D2, in ragweed-sensitive patients. Similarly, nasal epithelial mast cell numbers are decreased. A characteristic feature of immunotherapy is its ability to inhibit late-phase responses. In the nose it is accompanied by a decrease in eosinophil numbers in lavage during late responses. Characteristic changes in serum immunoglobulins are found, with an initial increase in IgE followed by a blunting of seasonal increases in IgE in pollen-sensitive patients and a gradual decline in allergen-specific IgE levels over several years. This is accompanied by an increase in allergen-specific IgG (blocking antibodies), although neither appear to correlate closely with the clinical response to immunotherapy. One way in which immunotherapy may act is by modifying the T-lymphocyte response to subsequent natural allergen exposure. Studies in peripheral blood and within the target organ have demonstrated a shift in the balance of T-cell subsets away from TH2-type (producing particularly IL-4 and IL-5) in favor of a TH1-type T-lymphocyte response (with the preferential production of IFN-gamma). Studies of the nasal mucosa before and after immunotherapy have demonstrated suppression of the late nasal response and increases in the numbers of cells expressing mRNA for IFN-gamma. It is not clear whether this immune deviation is due to anergy of TH2/TH0 cells or increases in TH0/TH1 T-lymphocyte responses. An alternative may be amplification of suppressor CD8+ T cells, which may have a downregulatory effect. Novel approaches currently being explored include the use of T-cell reactive peptides, which might circumvent the risk of anaphylaxis, and the use of adjuvants such as IL-12 or mycobacterial vaccines to potentiate the effects of allergen in inducing immune deviation.

Intranasal fluticasone propionate. A reappraisal of its pharmacology and clinical efficacy in the treatment of rhinitis

The intranasal corticosteroid fluticasone propionate is an effective agent for the treatment of rhinitis, demonstrating potent local anti-inflammatory activity and little, if any, systemic activity. Intranasal fluticasone propionate has shown clinical efficacy similar to that of other intranasal corticosteroids, including beclomethasone (administered at up to a 2-fold higher dosage than fluticasone), budesonide, flunisolide and triamcinolone acetonide, and provides greater relief from nasal symptoms (including nasal blockage) than antihistamine agents and intranasal sodium cromoglycate. Its efficacy in the treatment of seasonal allergic rhinitis and perennial allergic and nonallergic rhinitis has been demonstrated in large well-controlled studies in which the drug maintained adequate control of symptoms when administered in a once daily dose of 200 micrograms. In addition, fluticasone propionate has shown similar efficacy to that of beclomethasone in the treatment of nasal polyps; however, its use in the postoperative setting requires further investigation. Intranasal fluticasone propionate is well tolerated in the majority of patients, the incidence of adverse events being similar to that seen with placebo. Pharmacoeconomic analyses indicate that intranasal fluticasone propionate is significantly more cost-effective than the antihistamines terfenadine and loratadine. Overall quality of life was improved to a similar extent by fluticasone propionate and beclomethasone. In conclusion, recent clinical experience has confirmed that intranasal fluticasone propionate is a convenient, effective and well tolerated alternative to other intranasal corticosteroids and antihistamines for the treatment of rhinitis when administered once daily.

The pharmacological basis for the treatment of perennial allergic rhinitis and non-allergic rhinitis with topical corticosteroids

The currently available respiratory topical corticosteroids are all effective at reducing the nasal symptoms of itch, sneezing, rhinorrhoea and obstruction associated with allergic rhinitis. The mechanism of action of corticosteroids is related to their anti-inflammatory activities. They have been documented to prevent fluid exudation and reduce the number of circulating inflammatory cells, including lymphocytes, mast cells, basophils, eosinophils, macrophages, and neutrophils. This occurs through multiple mechanisms, e.g. eosinophil infiltration is suppressed by preventing cytokine production, reducing local mechanisms of tissue infiltration, and decreasing eosinophil survival. Furthermore, corticosteroids also reduce preformed and newly-generated mediators (e.g. histamine, tryptase, prostanoids, leukotrienes), and inhibit production of cytokines and chemokines by inflammatory cells (e.g. IL-1 through IL-6, IL-8, RANTES, TNF-alpha, IFN-gamma and GM-CSF). The currently available corticosteroids differ pharmacologically. Fluticasone propionate appears to have the greatest affinity for the glucocorticoid receptor, and binds more quickly and dissociates more slowly from the receptor compared with other corticosteroids, suggesting a more prolonged duration of action. Its increased specificity for respiratory tissue may lead to greater potency with less potential for systemic adverse effects. Fluticasone propionate has been compared with other corticosteroids in animal models for relative topical and systemic potency, and according to these data, it has the most favourable risk-benefit ratio.

Increase in epithelial mast cell numbers in the nasal mucosa of patients with perennial allergic rhinitis

The aim of the study was to compare the numbers and distribution of mast cells in the nasal mucosa of perennial allergic rhinitis (PAR) patients and controls, as demonstrated by different staining methods for light microscopy. Biopsies of inferior turbinate mucosa were taken from 10 patients with PAR and 10 patients undergoing septoplasty or septorhinoplasty (control group). Sections for light microscopy were stained with azure A. chloroacetate esterase and an ABC immunohistochemical technique using antibody to tryptase. Three times more mast cells were found in the epithelium of PAR patients compared to controls using the immunohistochemical technique (p = 0.0074). This method demonstrated considerably more mast cells than the other stains. The increase in epithelial mast cells is consistent with the migration of mast cells seen in seasonal allergic rhinitis, and this may be important in the phenomenon of nasal priming seen after repeated antigen exposure.

Treatment of allergic rhinitis

An increased understanding of the pathophysiology of allergic rhinitis can provide a logical basis for improved therapeutic strategies tailored individually to each patient. The first recommendation is the avoidance of possible or verified allergens. If this does not provide significant relief or is impractical, then immunotherapy plays a preventative role in some patients and it has been shown to be effective in certain cases. Initially, most patients try new nonsedating antihistamines, sometimes combined with a short course of topical vasoconstrictors. When nasal obstruction is a problem, a steroid spray is preferred. It is often necessary to add topical treatment for eye symptoms, e.g. antihistamine or cromoglycate eyedrops. In severe cases simultaneous administration of nasal corticosteroids and nonsedating antihistamines may achieve optimal control of symptoms. Cromolyn derivates are also effective in mild or moderate rhinoconjunctivitis and are especially recommended in the treatment of children. Systemic corticosteroid therapy should be reserved for the rare patient with extreme symptoms, and limited to short courses. Recent studies have shown that if patients are provided with appropriate medication, education and instruction, symptoms of allergic rhinitis can be well controlled with minimum impairment of quality of life.

Effect of 3 months' nasal steroid therapy on nasal T cells and Langerhans cells in patients suffering from allergic rhinitis

The effect of nasal corticosteroid therapy on allergic rhinitis is uncertain. In a double-blind, placebo-controlled study over 3 months, we investigated the influence of a new corticosteroid spray, fluticasone propionate aqueous nasal spray (FPANS), on Langerhans cells (CD1a+ cells), HLA-DR+ cells, and T cells in nasal mucosa. Efficacy was evaluated by nasal symptom score. This treatment significantly decreased the number of CD1a+ cells and HLA-DR+ cells in the nasal mucosa. Furthermore, a clear trend of decreasing numbers of T cells in nasal epithelium was found. No change in nasal symptom score was found after the treatment period. These findings suggest that fluticasone propionate aqueous nasal spray decreases the antigen presentation in nasal allergy.

Proteinase content of mast cells of nasal mucosa; effects of natural allergen exposure and of local corticosteroid treatment

The distribution and density of metachromatic cells (MCC) and mast cells containing chymase plus tryptase (MCTC) or tryptase alone (MCT) were studied in the nasal mucosa by dye-binding methods and immunohistochemical analysis. Biopsies were obtained from 17 subjects with birch pollen allergy before and during the peak season and from nine healthy controls. Six patients were treated with an intranasal glucocorticosteroid before and during the season in an open study. Hay fever patients, even when asymptomatic, showed signs of mast cell system activation, exhibiting an increased number of mast cells in the nasal epithelium. Basophils, lacking immunohistochemically detectable tryptase, were not a major component of the mast cell response. MCT, most conspicuous in the epithelium, were found to be the most frequent mast-cell type in the nasal mucosa of allergic, but not of normal, subjects. Only 33% of the epithelial, but 90% of the stromal, immunopositive cells in the atopic mucosa before as well as during the season were MCC. Intraepithelial MCT thus displayed a low capacity to stain metachromatically, indicating a relative deficiency of the glycosaminoglycan (heparin) component of the granules. Intraepithelial mast cells also appeared to be markedly sensitive to steroid treatment and aldehyde fixation. The findings suggest that the lack of chymase, the characteristic feature of MCT, may reflect a functional activation of the mast cells, rather than a stable phenotypic differentiation related to anatomic site.

Nasal cytological changes following pharmacological intervention

Symptoms of allergic rhinitis are associated with increased numbers of inflammatory cells in the nasal mucosa. The effects of fluticasone propionate on the nasal mucosal cells of patients with symptomatic allergic rhinitis were evaluated in seven multicentre, double-blind, parallel-group, placebo-controlled, randomised studies. In three seasonal allergic rhinitis studies, significantly more patients receiving fluticasone propionate had a decrease in nasal eosinophils following treatment compared with patients receiving placebo. Similarly, more patients receiving fluticasone propionate had a decrease in nasal basophilic cells, but differences from placebo were not significant in all studies. Nearly identical results were observed in two 24-week perennial allergic rhinitis studies: significantly more patients receiving fluticasone propionate or beclomethasone dipropionate had a decrease in nasal eosinophils compared with patients receiving placebo. Furthermore, a higher percentage of patients receiving corticosteroids also had a decrease in the number of basophilic cells. In two separate seasonal allergic rhinitis studies, significantly more patients receiving fluticasone propionate had a decrease in nasal eosinophils compared with patients receiving terfenadine or astemizole, respectively. The decrease in nasal basophilic cells was also significantly greater with fluticasone propionate compared with astemizole. Inhibition of mediator release from eosinophilic and basophilic cells has also been demonstrated in patients receiving fluticasone propionate compared with patients receiving antihistamines. The results of these studies suggest that the therapeutic benefits of fluticasone propionate aqueous nasal spray in the treatment of seasonal and perennial allergic rhinitis may be related to its ability to reduce nasal mucosal inflammatory cells and to inhibit local mediator activity.

Influence of prolonged treatment with topical corticosteroid (fluticasone propionate) on early and late phase nasal responses and cellular infiltration in the nasal mucosa after allergen challenge

We have examined the effect of prolonged treatment with topical corticosteroid on allergen-induced early and late nasal responses and the associated inflammatory cell infiltrate in grass pollen sensitive allergic rhinitics. Following a randomized double-blind 6 week treatment period with fluticasone propionate 200 micrograms aqueous nasal spray twice daily or matched placebo spray, nasal provocation was performed using Timothy grass pollen extract. Nasal symptoms were recorded at intervals from 0 to 24 h. Nasal biopsies were performed before treatment and at 24 h after allergen and processed for immunohistology. When corticosteroid-treated patients were compared with the placebo group there was an approximately 50% decrease in the size of the early (0-60 min) response and almost complete inhibition of late (1-24 h) nasal symptoms after allergen challenge. After allergen challenge markedly fewer T lymphocytes and CD25+ (interleukin-2 receptor bearing) cells were observed in both the epithelium and submucosa in fluticasone treated patients compared with the placebo group. Significantly less total and activated eosinophils were observed, particularly within the nasal epithelium. Submucosal mast cell counts were decreased, whereas increased numbers of submucosal neutrophils were observed. These results confirm that topical corticosteroid treatment inhibits allergen-induced early and late nasal responses. This may possibly occur following a decrease in T lymphocytes and/or mast cells and their products and a consequent reduction in tissue eosinophilia.

Allergic inflammation

A greater understanding of the basic mechanisms of allergic inflammation is pertinent to the development of new treatments. Previous studies have focused on the role of mediators of hypersensitivity and effector cells, including mast cells and eosinophils. Recent evidence suggests that IgE-dependent activation and tissue eosinophilia are under the local regulation of distinct cytokines. Originally described as products from T lymphocytes, these peptide messengers are produced by alternative cells, including mast cells, eosinophils and the respiratory epithelium. In vitro studies in murine models and using cloned human T lymphocytes indicate the preferential production of "Th2-type" cytokines, including interleukin-4 (IL-4) and IL-5. This review considers the evidence from in vivo studies in humans that "Th2-type" cytokines have a primary role in orchestrating both IgE-dependent events and local tissue eosinophilia. Novel therapeutic approaches might include a broad strategy directed against T lymphocytes, including the use of immunosuppressive agents or anti CD4 antibodies or more precise targeting of IL-4 and/or IL-5.

Dynamics of mast cells in the nasal mucosa of patients with allergic rhinitis and non-allergic controls: a biopsy study

Mast cell degranulation is thought to be an important component of the pathogenesis of allergic rhinitis. Quantitative studies on mast cells in nasal mucosa after allergen exposure have given widely divergent results, ranging from an overall decrease via redistribution to an overall increase. We investigated this problem by employing a combination of anti-IgE and toluidine blue staining of biopsy specimens. In allergic patients anti-IgE was found to identify all mast cells and toluidine blue to detect mast cells that were not (totally) degranulated. The study was composed of two parts done in different patient groups. In the first part of the study biopsies were performed in 23 patients with isolated grass-pollen allergy, once during natural provocation in the summer and once in the winter. Biopsies were also performed in 12 controls. Non-allergic controls were found to have the same number of mast cells in the lamina propria as asymptomatic allergic patients. The controls seldom have mast cells in the epithelium. The patients with isolated grass-pollen allergy showed an increase in the numbers of mast cells in the lamina propria during natural provocation and the same seemed to occur in the epithelium as well. During natural provocation almost all of the mast cells in the epithelium and half of those in the lamina propria were degranulated. In the second part of the study 17 patients with isolated grass-pollen allergy and four controls were challenged daily with allergen extract during a 2-week period in the winter. During this period biopsies were performed at eight different occasions, i.e. once before, six occasions during and once after the provocation period. The results of this part of the study showed that during provocation mast cells migrate to the surface of the nasal mucosa, where they become degranulated, and that the pool of mast cells in the lamina propria was apparently replenished by migration of mast cells from the vessels in the lamina propria. The total number of mast cells in the lamina propria remained approximately the same while the mast cells residing in an increasingly thick layer measured from the basal membrane into the lamina propria became degranulated. After 2 weeks, 82% of the mast cells in the lamina propria was degranulated and it was only in the deepest layers that some toluidine blue positive cells were found.(ABSTRACT TRUNCATED AT 400 WORDS)

The effects of topical fluticasone propionate on allergen-induced immediate nasal airways response and eosinophil activation: preliminary results

Nasal application of grass pollen allergen in atopic individuals with seasonal rhinitis leads to an early rise in nasal airways resistance. The effects of fluticasone propionate, a powerful, topically active glucocorticosteroid, on nasal airways resistance and cellular infiltration of the nasal mucous membrane were investigated. Fluticasone propionate blunted the rise in nasal airway resistance following allergen challenge (P = 0.089). Although this glucocorticosteroid did not affect the total number of eosinophils in biopsies of nasal mucous membrane, the number of activated eosinophils was significantly reduced (P less than 0.05).

A new approach to the treatment of asthma

Asthma is a chronic inflammatory condition. The previous emphasis on bronchodilator therapy, which does not treat the underlying inflammation, may be misplaced. Earlier introduction of antiinflammatory agents, such as corticosteroids or cromolyn sodium, is strongly recommended. Effective suppression of airway inflammation reduces the need for bronchodilator therapy and may reduce the morbidity and, perhaps, mortality of asthma.