Effect of topical corticosteroids on the recovery of histamine releasing factors in nasal washings of patients with allergic rhinitis. A double-blind, randomized, placebo-controlled study

Allergic rhinitis in children : diagnosis and management strategies

The incidence of allergic rhinitis has been increasing for the last few decades, in keeping with the rising incidence of atopy worldwide. Allergic rhinitis has a prevalence of up to 40% in children, although it frequently goes unrecognized and untreated. This can have enormous negative consequences, particularly in children, since it is associated with numerous complications and comorbidities that have a significant health impact on quality of life. In fact, allergic rhinitis is considered to be a risk factor for asthma. There are numerous signs of allergic rhinitis, particularly in children, that can alert an observant clinician to its presence. Children with severe allergic rhinitis often have facial manifestations of itching and obstructed breathing, including a gaping mouth, chapped lips, evidence of sleep deprivation, a long face, dental malloclusions, and the allergic shiner, allergic salute, or allergic crease. The medical history is extremely important as it can reveal information regarding a family history of atopy and the progression of atopy in the child. It is also important to identify the specific triggers of allergic rhinitis, because one of the keys to successful management is the avoidance of triggers. A tripartite treatment strategy that embraces environmental control, immunotherapy, and pharmacologic treatment is the most comprehensive approach. Immunotherapy has come to be viewed as potentially prophylactic, capable of altering the course of allergic rhinitis. The most recent guidelines for the management of allergic rhinitis issued by the WHO recommend a tiered approach that integrates diagnosis and treatment, in which allergic rhinitis is subclassified both by frequency, as either intermittent or persistent, and by severity, as either mild or moderate to severe. Oral or topical antihistamines and intranasal corticosteroids are the mainstay of pharmacologic therapy for allergic rhinitis, depending upon its severity, and several agents have been approved for use in children aged 5 years old and younger.

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.

Onset of action of mometasone furoate nasal spray (NASONEX) in seasonal allergic rhinitis

BACKGROUND

Mometasone furoate nasal spray (MFNS, NASONEX ), is a new synthetic corticosteroid with considerable efficacy in the treatment of seasonal and perennial rhinitis and less than 0.1% systemic absorption. This study was designed to evaluate the time of onset of action of MFNS. The subjects were evaluated over the course of 2 weeks during the spring allergy season.

METHODS

The effects of MFNS 200 microg given once daily for 2 weeks were evaluated in a randomized, multicenter, double-blind, placebo-controlled study in 201 patients with seasonal allergic rhinitis. Clinically significant onset of action was assessed prospectively by special patient diary cards kept during the first 3 days of treatment.

RESULTS

By 12 h after initial dosage (the earliest evaluation), 28% of patients in the MFNS group experienced clinically significant relief, compared with 13% of those given placebo (P = 0.01). Median time to at least moderate symptom relief in patients who received MFNS was 35.9 h, compared with more than 72 h in patients given placebo (P<0.01). By 72 h, 64% of the patients receiving MFNS experienced at least moderate relief, compared with 40% of those treated with placebo (P<0.01). Both patient and physician ratings of symptom severity, response to treatment, and overall condition of rhinitis indicated significant (P<0.01) superiority of MFNS over placebo. MFNS was well tolerated, with adverse events comparable to placebo.

CONCLUSIONS

MFNS provided rapid onset of clinically significant symptom relief in patients with seasonal allergic rhinitis.

Antigen-induced pleural eosinophilia is suppressed in diabetic rats: role of corticosteroid hormones

Previous studies have evidenced for the existence of interactive regulatory mechanisms between insulin and steroid hormones in different systems. In this study, we have investigated whether endogenous corticosteroids could be implicated in the hyporeactivity to antigen challenge observed in sensitized diabetic rats. Alloxinated rats showed a long-lasting increase in the blood glucose levels and a reduction in the number of pleural mast cells at 48 and 72 hr, but not at 24 hr after alloxan administration. In parallel, they also showed a significant elevation in the plasma levels of corticosterone together with an increase in the adrenal/body weight ratio. Antigen-evoked eosinophil accumulation appeared significantly reduced in rats pretreated with dexamethasone as well as in those rendered diabetic 72 hr after alloxan. In the same way, naive animals treated with dexamethasone also responded with a significant decrease in the number of pleural mast cells. Interestingly, when sensitized diabetic rats were pretreated with the steroid antagonist RU 38486 a reversion of the reduction in the allergen-induced eosinophil accumulation was noted. We conclude that the down-regulation of the allergic inflammatory response in diabetic rats is close-related to reduction in mast cell numbers and over expression of endogenous corticosteroids.

Intranasal fluticasone propionate inhibits recovery of chemokines and other cytokines in nasal secretions in allergen-induced rhinitis

BACKGROUND

Allergen-induced nasal responses are associated with the recovery of proinflammatory mediators and cytokines. In recent years, a distinct group of chemotactic cytokines, chemokines, has been the focus of intense investigation as to their possible role in the pathogenesis of allergic diseases. Although corticosteroids have been known to be effective in the treatment of allergic diseases, their mechanism(s) of action has not been fully elucidated.

OBJECTIVES

To study the effect of topical fluticasone on the recovery of chemokines (IL-8, MIP-1 alpha, and RANTES) and other cytokines (IL-1 beta, IL-6, and GM-CSF) from nasal mucosa following allergen challenge. To correlate the improvement of rhinitis symptoms with cytokine levels during early-phase and late-phase allergic responses.

METHODS

A randomized, double-blind, placebo-controlled crossover study of fluticasone propionate, 200 micrograms q d, was performed in ten subjects with allergic rhinitis. Allergen challenge was administered after 1 week of treatment. Nasal secretions were collected immediately after challenge and during the late-phase reactions; symptom scores were recorded simultaneously. Nasal cytokines were assayed by specific ELISA.

RESULTS

The allergen challenge caused early-phase and late-phase allergic reactions and increased recovery of IL-1 beta, IL-6, IL-8, RANTES, MIP-1 alpha, and GM-CSF from the nasal mucosa. Intranasal fluticasone inhibited the allergen-induced increase in nasal symptoms. This was associated with decreases in cytokine recovery. A significant correlation was observed between decreases in cytokine levels and in symptom scores after treatment.

CONCLUSION

Our results suggest that treatment with topical fluticasone propionate inhibits allergen-induced nasal responses and the associated increase in the production/secretion of chemokines and other proinflammatory cytokines.

Clinical review of once-daily beclomethasone dipropionate for seasonal allergic rhinitis

A new double-strength (84 micrograms/spray) formulation of beclomethasone dipropionate (BDP-ds) as an aqueous suspension has been introduced to control symptoms of allergic rhinitis with once-daily intranasal dosing. This paper reviews the results of three clinical reports which show that BDP-ds given once a day is more effective than placebo and as effective as regular-strength beclomethasone dipropionate given twice daily in reducing the nasal symptoms of seasonal allergic rhinitis. Symptom improvement was seen within 2 days of treatment initiation and was maintained for the subsequent 4 weeks. BDP-ds was found to be as safe and well tolerated as placebo. Adverse effects, which were generally mild, included headache, nasal burning/irritation, epistaxis, coughing, and pharyngitis. BDP-ds is safe for children as young as 6 years of age, and its once-daily dosing schedule may improve patient compliance.

Chemokines in seasonal allergic rhinitis

Monocyte chemotactic and activating factor/monocyte chemoattractant protein-1 (MCAF/MCP-1), RANTES, and macrophage inflammatory protein (MIP)-1 alpha are chemokines known to activate basophils (MCAF/RANTES) and eosinophils (RANTES/MIP-1 alpha). IL-8 inhibits MCAF-induced histamine release from basophils. We questioned whether a relationship exists between the levels of these chemokines and various inflammatory mediators released from mast cells, eosinophils, and basophils as assessed in nasal secretions obtained from patients during the allergy season and out of season. Samples were assessed for MCAF/MCP-1, RANTES, MIP-1 alpha, IL-8, histamine, tryptase and eosinophil cationic protein (ECP) in three subject groups: subjects with allergic rhinitis (n = 18), atopic subjects without rhinitis (n = 9), and healthy individuals (n = 6). Statistically significant differences were apparent only in the subjects with symptoms as follows. MCAF/MCP-1 increased during the season from 336 +/- 47 pg/ml to 829 +/- 137 pg/ml (p < 0.001), whereas IL-8 decreased from a baseline of 1932 +/- 335 pg/ml to 1070 +/- 202 pg/ml (p < 0.028). The ratio of IL-8 to MCAF/MCP-1 decreased during the symptomatic season from the baseline of 6.66 +/- 1.06 seen during winter to 1.3 +/- 0.22 during ragweed season (p < 0.001). Histamine increased from 6.3 +/- 1.5 to 89 +/- 15.5 ng/ml (p < 0.001), ECP increased from 20.6 +/- 6.4 to 237.1 +/- 50.2 ng/ml (p < 0.001), and tryptase increased from 2.34 +/- 0.6 to 9.7 +/- 2.3 U/ml (p < 0.001). Most samples did not have detectable quantities of MIP-1 alpha or RANTES. We also found a correlation between the level of MCAF/MCP-1 and IL-8 and the level of histamine or IL-8 and ECP. Our results suggest that the chemokines MCAF/MCP-1 and IL-8 may participate in the pathogenesis of allergic rhinitis, contributing to the attraction of the proinflammatory cells and mediator release, which might be very important during the late phase of the allergic reaction. Furthermore, the ratio of certain chemokines, such as MCAF/MCP-1 and IL-8 may reflect the magnitude of the reaction, as does the presence of histamine and ECP.

Effectiveness and safety of beclomethasone dipropionate, an intranasal corticosteroid, in the treatment of patients with allergic rhinitis

There is an increasing trend toward topical intranasal corticosteroids as the preferred treatment for seasonal or perennial allergic rhinitis. This trend is based on the fact that the chronic, mucosal inflammation that accompanies allergic rhinitis responds to anti-inflammatory drugs such as topical corticosteroids. Intranasal corticosteroids, given before the natural antigen challenge, reverse preexisting inflammation and prevent nasal priming by antigens. One intranasal corticosteroid, beclomethasone dipropionate, has been available by prescription in the United States for more than a decade and has an established efficacy and safety profile in patients with allergic rhinitis. Beclomethasone dipropionate has become the standard to which other intranasal corticosteroid preparations are compared. In comparison with earlier corticosteroids (eg, hydrocortisone, prednisolone, dexamethasone, betamethasone) that caused adrenal suppression and other systemic adverse reactions, the actions of new corticosteroids, including beclomethasone dipropionate, are confined to the site of application. These drugs are also more rapidly metabolized, less irritating to the nasal mucosa, and have a longer duration of action. When given intranasally to relieve the sneezing, congestion, and rhinorrhea associated with seasonal and perennial allergic rhinitis, the newer corticosteroids have proved safe and effective. Despite the fact that topical nasal corticosteroids such as beclomethasone dipropionate are responsible for important improvements in the treatment of both allergic and nonallergic rhinitis as well as nasal polyposis and chronic sinusitis, these drugs may be underused, particularly in the pediatric population. Because of the concern of systemic side effects in younger children, less effective therapies are sometimes used.

Chemokines and the allergic response

The beta subfamily of chemokines contains cytokine-like factors which are chemotactic for human basophils and eosinophils. The also stimulate these cells to secrete pro-inflammatory substances such as histamine or eosinophil cationic protein. MCAF/MCP-1, MCP-2, MCP-3, RANTES and MIP-1 alpha all attract and stimulate basophils; MCP-1 and MCP-3 are the most potent. RANTES, MCP-3 and to a lesser degree MIP-I alpha are chemotactic factors and activators of eosinophils. Cytokines such as IL3, IL5 and GM CSF can augment the responses of these cells to the various chemokines and function as primers. These substances may have particular importance as mediators of allergic inflammation, particularly the late phase component of the response.