Early and late nasal symptom response to allergen challenge. The effect of pretreatment with a glucocorticosteroid spray

Nasal IL-13 production identifies patients with late-phase allergic responses

BACKGROUND

There is limited knowledge on how local cytokine secretion patterns after nasal allergen challenge correlate with clinical symptoms especially with regard to the "late allergic response," which occurs in approximately 40% to 50% of patients with allergy.

OBJECTIVE

We sought to characterize the immunologic and clinical nasal responses to birch pollen allergen challenge with a special focus on the late allergic response.

METHODS

In this randomized, double-blind, placebo-controlled trial, birch pollen-allergic participants were challenged with birch pollen extract (n = 20) or placebo (n = 10) on 3 consecutive days. On days 1 and 3, nasal secretions were collected at selected time points over a 24-hour time course for the measurement of 33 inflammatory mediators. Clinical responses were determined through subjective symptom scores and objective nasal airflow measurements.

RESULTS

Provoked participants had significantly greater clinical responses and showed significant increases in tryptase and the soluble IL-33 receptor serum stimulation 2 (sST2) in nasal secretions within minutes compared with the placebo group. Eight of 20 provoked participants displayed high IL-13 levels 2 to 8 hours after allergen provocation. This group also showed significant changes in clinical parameters, with a secondary drop in nasal airflow measured by peak nasal inspiratory flow and increased symptoms of nasal obstruction, which significantly differed from IL-13 nonresponders after 6 hours.

CONCLUSIONS

IL-13 response status correlates with clinical responses and type 2 cytokine responses in the late phase after allergen provocation.

Repetitive nasal allergen challenge in allergic rhinitis: Priming and Th2-type inflammation but no evidence of remodelling

BACKGROUND

Local tissue eosinophilia and Th2 cytokines are characteristic features of seasonal allergic rhinitis. Airway remodelling is a feature of asthma whereas evidence for remodelling in allergic rhinitis (AR) is conflicting.

OBJECTIVE

By use of a novel human repetitive nasal allergen challenge (RAC) model, we evaluated the relationship between allergic inflammation and features of remodelling in AR.

METHODS

Twelve patients with moderate-severe AR underwent 5 alternate day challenges with diluent which after 4 weeks were followed by 5 alternate day challenges with grass pollen extract. Nasal symptoms, Th1/Th2 cytokines in nasal secretion and serum were evaluated. Nasal biopsies were taken 24 hours after the 1st and 5th challenges with diluent and with allergen. Sixteen healthy controls underwent a single challenge with diluent and with allergen. Using immunohistochemistry, epithelial and submucosal inflammatory cells and remodelling markers were evaluated by computed image analysis.

RESULTS

There was an increase in early and late-phase symptoms after every allergen challenge compared to diluent (both P < .05) with evidence of both clinical and immunological priming. Nasal tissue eosinophils and IL-5 in nasal secretion increased significantly after RAC compared to corresponding diluent challenges (P < .01, P = .01, respectively). There was a correlation between submucosal mast cells and the early-phase clinical response (r = 0.79, P = .007) and an association between epithelial eosinophils and IL-5 concentrations in nasal secretion (r = 0.69, P = .06) in allergic rhinitis. No differences were observed after RAC with regard to epithelial integrity, reticular basement membrane thickness, glandular area, expression of markers of activation of airway remodelling including α-SMA, HSP-47, extracellular matrix (MMP7, 9 and TIMP-1), angiogenesis and lymphangiogenesis for AR compared with healthy controls.

CONCLUSION

Novel repetitive nasal allergen challenge in participants with severe persistent seasonal allergic rhinitis resulted in tissue eosinophilia and increases in IL-5 but no structural changes. Our data support no link between robust Th2-inflammation and development of airway remodelling in AR.

Establishment of a new animal model of allergic rhinitis with biphasic sneezing by intranasal sensitization with Staphylococcal enterotoxin B

Allergic rhinitis (AR) is a global health problem. The effectiveness of currently available medications is limited and therefore investigation for more effective drugs is essential. The aim of the present study was to establish a model of AR in guinea pigs that can be utilized for the further investigation of new drugs. Guinea pigs were intranasally sensitized with 1 µg Staphylococcal enterotoxin B (SEB) dissolved in 40 µl saline once daily for 14 days. One week after the last sensitization, the same treatment was applied intranasally once every four days for a total of 30 times. In the treatment group, terfenadine was administered orally 70 min before the 4th, 14th and 24th challenge. Sneezing and nasal scratching were evaluated following each of the 30 challenges. The quantity of antigen-specific antibodies in the serum was measured. Between the 19th and 30th challenges, the guinea pigs in the model group produced significant biphasic elevations in sneezing number, with peaks 10 min-2 h and 4-8 h after the SEB challenges. In addition, the guinea pigs produced significantly more sneezing in the first peak during the 19th to 30th challenges than during the first to 18th challenges (P<0.01). Terfenadine significantly inhibited the early- and late-phase sneezing at all challenge times. The serum levels of SEB-specific immunoglobulin (Ig) E and IgG₁ were higher in the model group in comparison with those in the control group (P<0.01). This experiment demonstrated that SEB can induce typical AR with biphasic sneezing in guinea pigs. Histamine may play an important role in the early- and the late-phase sneezing in the model of AR. This model can be potentially used for the investigation of new drugs.

Role of leukotriene antagonists and antihistamines in the treatment of allergic rhinitis

Allergic rhinitis is the most common atopic disorder seen in ENT clinics. It is diagnosed by history, physical exam and objective testing. Patient education, environmental control measures, pharmacotherapy, and allergen-specific immunotherapy are the cornerstones of allergic rhinitis treatment and can significantly reduce the burden of disease. Current treatment guidelines include antihistamines, intranasal corticosteroids, oral and intranasal decongestants, intranasal anticholinergics, intranasal cromolyn, and leukotriene receptor antagonists. In the mechanism of allergic rhinitis, histamine is responsible for major allergic rhinitis symptoms such as rhinorrhea, nasal itching and sneezing. Its effect on nasal congestion is less evident. In contrast, leukotrienes result in increase in nasal airway resistance and vascular permeability. Antihistamines and leukotriene receptor antagonists are commonly used in the treatment of allergic rhinitis. The published literature about combined antihistamines and leukotriene antagonists in mono- or combination therapy is reviewed and presented.

Immediate and dual response to nasal challenge with Dermatophagoides pteronyssinus in local allergic rhinitis

BACKGROUND

Local allergic rhinitis (LAR) is characterized by in situ production of specific IgE (sIgE) antibodies and a positive response to a nasal allergen provocation test (NAPT) in the absence of atopy.

OBJECTIVE

The aim of this study was to investigate the immunological mechanisms involved in the immediate and late responses after nasal exposure to Dermatophagoides pteronyssinus (DP) in patients with LAR.

METHODS

A total of 40 subjects with LAR to DP were studied and compared with 50 healthy controls. Immediate and late responses to NAPT-DP were assessed using a visual analogue scale of nasal symptoms and acoustic rhinometry. Tryptase, ECP, total and sIgE-DP were measured in the nasal lavage by immunoassay at baseline, 15 min, 1, 6 and 24 h after nasal challenge.

RESULTS

NAPT-DP was positive in all patients, with significant increases in tryptase (45%), ECP (65%) and sIgE-DP (25%) (P<0.05). Sixty percent of the LAR patients presented an immediate response to NAPT-DP and 40% a dual response. Immediate responders showed a fast release of tryptase with a peak at 15 min after NAPT-DP, and a progressive increase in nasal ECP and sIgE-DP from 1 to 24 h after challenge, with a peak at 24 h. Dual responders presented persistently higher levels of tryptase from 15 min to 6 h after challenge, and a similar pattern of nasal release of ECP and sIgE-DP to immediate responders. There were no isolated late responders. NAPT-DP was negative in all healthy controls, with no increases in tryptase, ECP, or total and sIgE-DP in nasal secretions.

CONCLUSIONS

The results demonstrated the existence of immediate and dual responses to a NAPT with DP in LAR patients, with the local presence of sIgE and mast cell/eosinophil activation.

Nasal inflammatory mediators and specific IgE production after nasal challenge with grass pollen in local allergic rhinitis

BACKGROUND

Evidence exists of a new form of local allergic rhinitis (LAR) with local production of specific IgE (sIgE) and a positive response to nasal allergen provocation test (NAPT) in patients previously diagnosed with idiopathic rhinitis. However, the immunologic mechanisms involved are still poorly understood.

OBJECTIVE

We explored the involvement of nasal sIgE, eosinophil, and mast cell activation in the response to NAPT with grass pollen (NAPT-grass) in a group of patients already classified with LAR.

METHODS

Out-of-spring NAPT-grass was performed in 30 patients with LAR and 30 healthy controls. Nasal symptoms, acoustic rhinometry, and nasal lavage were performed at baseline and 15 minutes and 1, 6, and 24 hours post-NAPT. Tryptase, eosinophilic cationic protein (ECP), and total and sIgE to grass pollen were measured in nasal lavage by immunoassays.

RESULTS

NAPT-grass was positive in all patients with LAR. We detected significant increases of tryptase and ECP in 40% and 43%, respectively, at 15 minutes and 1, 6, and 24 hours post-NAPT compared with baseline (P < .05). sIgE was increased in 30%, with significant increases at 1 and 6 hours (P < .05) and 24 hours (P = .002) post-NAPT. The maximum release of tryptase was detected 15 minutes after NAPT, whereas the maximum release of ECP and sIgE was detected 24 hours after challenge. NAPT-grass was negative in all healthy controls, with no increase in tryptase, ECP, total IgE, or sIgE.

CONCLUSION

These results demonstrate that patients with LAR had local production of sIgE and mast cell/eosinophil activation induced by nasal exposure to grass pollen.

Glucocorticosteroids in allergic inflammation: clinical benefits in allergic rhinitis, rhinosinusitis, and otitis media

Allergic rhinitis, rhinosinusitis, and otitis media are among the most common health problems encountered in general practice. Although frequently trivialized, they affect the quality of life, represent a significant socioeconomic burden, and are associated with some serious complications. In addition, allergic rhinitis, rhinosinusitis, and otitis media are often considered as comorbidities. These disorders involve an inflammatory process of the respiratory mucosa of the nose, paranasal sinuses, or middle ear. Because of their well-known anti-inflammatory effects, the role of glucocorticosteroids in the management of these three disorders has been questioned, evaluated, and, in some cases, established.

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.

Immediate effect of topical budesonide on allergen challenge-induced nasal mucosal fluid levels of granulocyte-macrophage colony-stimulating factor and interleukin-5

The nasal antiinflammatory effects produced by maintenance treatment with topical steroids include reduced production of cytokines. The present study explored nasal mucosal effects induced during the first 9 h after a single dose of topical budesonide. Nine subjects with allergic rhinitis due to birch or timothy pollen were given budesonide (256 microg; Rhinocort Aqua) or placebo in a double-blind, randomized, crossover (4 wk washout) manner. Nasal allergen challenges were performed 30 min after the steroid/placebo pretreatment. Before and 30 min, 1, 3, 5, 7, and 9 h after challenge, filter paper strips were placed on the nasal septum and inferior turbinates for 10 min to sample undiluted mucosal fluids. Strips were then extracted in 1 ml buffer for cytokine analysis (ELISA). Allergen challenge produced acute nasal symptoms that peaked at 30 min and then tapered off. Conversely, both GM-CSF and IL-5 were increased only at 3, 5, 7 and 9 h (p < 0.05 compared with baseline). Budesonide did not affect the nasal symptoms but inhibited (p < 0. 05; compared with placebo treatment) the allergen challenge-induced mucosal output of GM-CSF and IL-5. These data demonstrate that GM-CSF and IL-5 are induced in a nonsymptomatic, late phase response to nasal allergen challenge, and that this cytokine response is prevented by single dose budesonide pretreatment.

Clinical manifestations of the release of histamine and other inflammatory mediators

This article reviews the symptoms that are characteristic of the early- and late-phase allergic reaction. Each of the cardinal symptoms of seasonal allergic rhinitis (sneezing, pruritus, rhinorrhea, congestion) is discussed, as is the role of various chemical mediators in the expression of these clinical manifestations.

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.

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.

Effect of corticosteroids on nasal blockage in rhinitis measured by objective methods

This paper gives an overview of placebo-controlled studies of the effect of corticosteroid treatment on nasal blockage, based on objective measurements of nasal airway patency. A few studies of perennial rhinitis have indicated that pretreatment with an intranasal corticosteroid has a moderate effect on nasal hyperresponsiveness, measured as the histamine-induced increase of nasal blockage. Whereas the effect on allergen-induced early-phase symptoms is variable, the effect on the late-phase blockage is almost complete. In seasonal allergic rhinitis, a few studies have shown an effect of intranasal steroids on nasal airway resistance, nasal peak flow and on acoustic rhinometry, but there are no reports on the effect in adults with perennial rhinitis. In children with perennial disease, intranasal treatment results in increased nasal patency and, in one study, also in reduced mouth breathing and in an increased threshold for exercise-induced bronchoconstriction. In patients with nasal polyposis, intranasal steroids have an effect on nasal airway resistance and on nasal peak flow both before and after polypectomy. There is convincing evidence that intranasal corticosteroids provide a better effect than antihistamine on nasal blockage. Amazingly, there does not appear to be any report on the effect of systemic corticosteroid treatment on nasal airway patency, and it is therefore difficult to recommend this treatment in a rational dosage. In conclusion, there is a fairly good documentation in support of the efficacy of intranasal steroid treatment on nasal airway patency in rhinitis. An objective measurement of nasal airway patency ought to be the routine in controlled rhinitis trials.

An approach to the understanding of the nasal early-phase reaction induced by nasal allergen challenge

Quantitative determinations of the inflammatory mediators in nasal secretions were performed and correlated with the objective nasal symptoms within 1 h after nasal allergen challenge (NAC). Twenty-six patients with seasonal allergic rhinitis were enrolled outside the pollen season. All measurements were performed before (as a baseline control) and at 1, 5, 10, 30, and 60 min after NAC. This study aimed to clarify the pathogenic mechanism of the early-phase reaction (EPR) by monitoring the evolution of early-phase mediators in nasal secretions and the presence of nasal symptoms during this period. The results showed that, after NAC, the maximal mediator concentration was already reached after 1 min for histamine (124 ng/g), 5 min for tryptase (56 microU/g), and 5-10 min for leukotriene C4 (40 ng/g). Itching and sneezing started as early as 20-30 s, and they were predominant symptoms within 5 min. Rhinorrhea and nasal obstruction started a few minutes after NAC and lasted until more than 1 h after NAC. There was no significant correlation between any single mediator and nasal symptoms during the sampling period. In conclusion, this study demonstrated that during the EPR the presence of nasal symptoms involves a complex mechanism, reflecting the interaction between the mediators released by inflammatory cells, and the receptors on different target organs. When evaluating symptoms during the EPR, one must consider not only the severity of these symptoms but also the time period within which these symptoms occur. For the symptoms of nasal obstruction and rhinorrhea, the early-phase reaction often lasted more than 1 h.

Challenge tests in nose and bronchi: pharmacological modulation of rhinitis and asthma

In order to study the pathophysiology of allergic airway disease and its response to pharmacotherapy, allergic and non-allergic provocation challenge techniques can be employed. Lower airway challenge has been used widely, but the use of nasal challenge is becoming more widespread as its advantages are realized. New measurement techniques are also being used (e.g. acoustic rhinometry), along with more classical methods such as spirometry, peak airflow rate and symptom scores, to determine the response to challenge. In the lungs, allergen challenge produces a biphasic response, which is less clearly defined in the nose. Topical histamine challenge closely resembles the effects of an allergic reaction and acts by stimulating sensory nerve endings. Methacholine is also often used for nasal challenge (often in addition to histamine), due to its effects on glandular sensitivity. Exercise induces bronchoconstriction in asthmatics and can be imitated by inhalation of cold, dry air. Cold air induces glandular hypersecretion and nasal discharge in normal subjects, which is increased in severity in rhinitic patients. Drug effect investigations using antihistamines have shown that histamine is important in producing the symptom of sneezing, whereas nasal blockage is due to vasodilatation rather than plasma exudation and oedema. Beta 2-agonists reduce allergen-induced symptoms by stabilizing mast cells, whereas cholinoceptor antagonists reduce watery nasal secretion. Increased responsiveness of sensory nerves and nasal glands is a characteristic clinical feature of asthma and rhinitis, which is responsible for the symptomatology. These effects can be reduced by topical corticosteroids.

The rationale for use of topical corticosteroids in allergic rhinitis

The rationale for using topical corticosteroids in the treatment of allergic rhinitis is that high drug concentrations can be achieved at receptor sites in the nasal mucosa, with minimal risk of systemic adverse effects. Topical corticosteroids have been demonstrated to reduce the number of Langerhans' cells (or their markers) in the nasal mucosa, and this is thought to attenuate antigen presentation. T lymphocytes have been identified as being significant in orchestrating the immune-inflammatory response, particularly the TH2 cells, which represent an important target for topical corticosteroids. TH2 cell-evoked mast cells and basophils are the sole producers of histamine, a mediator of major importance for rhinitis symptoms. Several studies have shown that the increased number of mast cells and basophils in the epithelium following antigen challenge/exposure, are markedly reduced by topical corticosteroids. Furthermore, the number of eosinophils, an important morphological marker of allergic rhinitis, can be profoundly reduced by treatment with topical corticosteroids. The rationale for topical treatment is strengthened by evidence of inhibition of cytokine release from surface epithelial cells, resulting in reduced recruitment and activation of mast cells, basophils, and eosinophils, which may be attributed to the high drug concentration achieved in epithelial cells. Ongoing inflammation in the mucous membrane is indicated by entry of plasma into the nasal lumen which subsides with the anti-inflammatory efficacy of topical corticosteroids. In contrast to antihistamine therapy, which has little effect on nasal blockage, pretreatment with topical corticosteroids results in almost complete attenuation of late-phase symptoms including nasal blockage, and moderate efficacy in early phase symptoms. Clearly, the spectrum of anti-inflammatory activity afforded by topical corticosteroid therapy is of clinical significance in reducing the three major symptoms of allergic rhinitis- sneezing, watery rhinorrhoea and nasal blockage.