Prostaglandin D2 measurement in nasal secretions is not a reliable marker for mast cell activation in atopic patients

Background Prosia gland in D2 (PGD2) is a very important mast cell product during the early-phase nasal allergic reaction. However, the quantification of PGD2 in nasal secretions has not yet been well established. Objective Quantitative determination of PGD2 in nasal secretions of atopic patients (n=17) after nasal allergen challenge (NAC) and in non-allergic healthy volunteers (n=10). Methods The nasal microsuction sampling technique was used to obtain the nasal secretions with an exactly known and minimally diluted volume. A sensitive and specific enzyme immunoassay was chosen to measure the more stable 11-methoxime derivative of PGD2. which was obtained after extraction in acelone/ethanol and conversion using methoxamine-HCl. The concentrations of PGD2 in nasal secretions obtained from 10 non-allergic healthy volunteers were used as reference values. Results There was no significant difference in the concentrations of PGD2 between men (median: 569pg/mL) and women (median: 407pg/mL), nor between the baseline concentrations from atopic patients (median: 410pg/mL) and non-allergic controls (median: 477 pg/mL). In the atopic patient group, PGD2 did not significantly increase during the entire sampling period after NAC. The absence of PGD2 response contrasted with the nasal symptoms manifested by sneezing, increased nasal airway resistance, and the significant increases of the concentrations of histamine, tryptase, and leukotriene C4 (LTC4) 5min after NAC. Conclusion This observation suggests that the measurement of PGD2 alone in the nasal secretions does not give reliable information on mast cell activation during a nasal allergic reaction.     

Monitoring nasal allergic inflammation by measuring the concentration of eosinophil cationic protein and eosinophils in nasal secretions

Quantitative measurement of the eosinophil cationic protein (ECP) concentration and the percentage of eosinophils in nasal secretions has greatly improved our understanding of the inflammatory process after natural allergen exposure. ECP and eosinophils were measured in the nasal secretions of 40 symptomatic patients with seasonal allergic rhinitis during the pollen season. Results showed a significant relationship between a high concentration of ECP (median: 410 ng/g, range: 6–2380 ng/g) and a high percentage of eosinophils (median: 13.5%, range: 1–85%). This quantitative study again demonstrated that infiltration by eosinophils and release of ECP play a key role in allergic rhinitis. It also suggests that the combined measurement of the percentage of eosinophils together with the ECP concentration in nasal secretions seems to be a very useful model in monitoring and assessing the condition of chronic nasal inflammation in patients with allergic rhinitis.     

Substance P and vasoactive intestinal peptide in serotonin-induced nasal secretions in normal subjects

The aim of this study was to examine if nasal secretions contained substance P and/or vasoactive intestinal peptide. Serotonin nasal challenge was performed in 14 normal subjects 15 min after intranasal pretreatment (double-blind) with atropine, methysergide, chlorpheniramine or isotonic saline. Serotonin induced a dose dependent increase in secretion (P less than 0.05), and only pretreatment with atropine reduced the secretion (P less than 0.02). Substance P, measured by radioimmunoassay, was found in all of the examined secretions (n = 100) with a median concentration of 13.7 pmol/l (range 1.7-125.0). Serotonin challenge increased the concentration or content of substance P in a dose-related fashion (P less than 0.01). The different pretreatments did not affect the concentration of substance P. Vasoactive intestinal peptide was found in low concentration in 37% of the secretions with a median concentration of 0 pmol/l (range 0-50.0).     

Blood markers of early and late airway responses to allergen in asthmatic subjects. Relationship with functional findings

We evaluated the relationship between blood markers of mast-cell (plasma histamine and serum level of heat-stable neutrophil chemotactic activity [NCA]) and eosinophil (serum eosinophil cationic protein [ECP]) activation during early airway response (EAR) and late airway response (LAR) to allergen inhalation in 24 asthmatic subjects. After EAR, 14 subjects showed significant LAR (FEV₁ fall: 25%), while 10 subjects showed equivocal LAR (FEV₁ fall: 15–20%). A significant increase from baseline value was observed in plasma histamine and in serum NCA during both EAR and LAR, while serum ECP significantly increased only during LAR. The sensitivity of different markers to detect significant FEV₁ fall during EAR and LAR was low, except for NCA. Changes in blood mediators were similar in both groups with significant and equivocal LAR. There was a significant relationship between the increase in NCA during EAR and the severity of LAR. Stepwise regression between changes in different blood markers showed a significant relationship between histamine increase during EAR and ECP increase during LAR. Thus, serum NCA is a more sensitive marker of EAR and LAR than plasma histamine and serum ECP, and its increase during EAR seems predictive of the severity of the subsequent LAR.     

Comparative nasal absorption of allergens in atopic and nonatopic subjects.

Based on sensitization following intranasal antigen administration, previous investigations have suggested greater absorption of allergens through the nasal mucous membranes of atopic than of nonatopic subjects. In this study mucosal absorption was assessed more directly by determining the capacity of allergens applied intranasally to elicit cutaneous Prausnitz-Küstner (P-K) reactions in nonatopic persons as compared with asymptomatic atopic subjects sensitive to other allergens. Two series of reaginic human serum dilutions were injected intracutaneously in recipients backs, and 48 hours later one series was challenged intracutaneously with test allergen. After the responses had been recorded, concentrated allergenic extract was sprayed into the nose and the second series of P-K sites observed for reactivity. Sometimes these P-K sites were rechallenged intracutaneously the following day to determine passive transfer neutralization. Two allergens were studied: bovine ribonuclease (RNase) and peanut extract. Two sera containing peanut reagins and one with RNase antibodies were each used in 10 to 11 atopic and 9 to 11 nonatopic recipients. The atopic group failed to show greater or more rapid absorption of either allergen through the nose based on the highest serum dilution reacting after nasal challenge. the speed of the reaction, the ratio of the titer by nasal challenge to the intracutaneous titer, or passive transfer neutralization. Controls showed that the results were not influenced by systemic absorption of allergen employed for intracutaneous tests. Drinking the amount of peanut extract applied intranasally did not elicit P-K reactions.     

Neutrophil chemotactic activity in milk-induced asthma

Four subjects with clinical histories of milk-induced asthma were studied (three allergic to cow's milk; one to soya milk). In each instance, skin prick tests, RAST (IgE and IgG₄), the basophil histamine release, and serum precipitins, using appropriate milk extracts, were negative. After the ingestion of milk all the subjects developed a reproducible and dose-dependent increase in airflow limitation. Three patients (two allergic to cow's milk; one to soya milk) gave a characteristic immediate-type reaction, which was maximal at 30 min after challenge. The fourth individual developed an isolated late-phase response, with maximal airways obstruction 3 hr after ingesting milk. In the three subjects who gave an early reaction, wheezing was accompanied by an elevation in circulating neutrophil chemotactic activity (NCA). This was not observed in the individual with the isolated late reaction. By Sephacryl S-400 gel-filtration chromatography it was shown that NCA of the early reactions eluted with proteins having an estimated molecular weight of 600,000 daltons. The immediate asthmatic response in peak expiratory flow rate and the elevation in NCA were inhibited by the prior oral administration of either disodium cromoglycate (DSCG) or oral beclomethasone dipropionate (BDP). In contrast, DSCG had no effect on airways obstruction in the subject with the isolated late asthmatic response, although inhibition was achieved by BDP.     

Enhanced basophil histamine release and neutrophil chemotactic activity predispose grain dust-induced airway obstruction.

BACKGROUND: The pathogenic mechanism of grain dust (GD)-induced occupational asthma (OA) remains unclear. OBJECTIVE: To understand further the mechanism of GD-induced OA. METHODS: Fifteen employees working in a same GD industry, complaining of work-related respiratory symptoms, were enrolled and were divided into two groups according to the GD-bronchoprovocation test (BPT) result: six positive responders were grouped as group III, nine negative responders as group II and five healthy controls as group I. Serum GD-specific immunoglobulin (Ig)E (sIgE), specific IgG (sIgG) and specific IgG4 (sIgG4) antibodies were detected by enzyme-linked immunosorbent assay. Basophil histamine release was measured by the autofluorometric method, and changes of serum neutrophil chemotactic activity were observed by the Boyden chamber method. RESULTS: For clinical parameters such as degree of airway hyperresponsiveness to methacholine, duration of respiratory symptoms, exposure duration, and prevalences of serum sIgE, sIgG and sIgG4 antibodies, there were no significant differences between group II and III (P > 0.05, respectively). Serum neutrophil chemotactic activity increased significantly at 30 min and decreased at 240 min after the GD-BPT in group III subjects (P < 0.05, respectively), while no significant changes were noted in group II subjects (P > 0.05). Basophil histamine release induced by GD was significantly higher in group III than those of group I or group II (P < 0.05, respectively), while minimal release of anti-IgG4 antibodies was noted in all three groups. CONCLUSIONS: These results suggest that enhanced basophil histamine release and serum neutrophil chemotactic activity might contribute to the development of GD-induced occupational asthma.     

Effects of H1-receptor antagonists on nasal obstruction in atopic patients

The aim of this study is to investigate whether H₁-receptor antagonists, besides their effect on nasal itching and sneezing, also have a measurable effect on nasal obstruction caused by allergen challenge. The antihistamine used was astemizole (10 mg) versus placebo, in a double-blind, cross-over, randomized study of two groups. Between the two sessions there was a wash-out period of at least 4 weeks. Seven patients of both sexes, with proven allergy to grass pollen, underwent a specific long-term provocation with grass pollen in the Vienna challenge chamber. Using a physiological method of challenge and a sensitive method for evaluating nasal function, we were able to prove H₁-receptor antagonist influence on nasal airway obstruction. The main parameters obtained arc nasal flow and nasal resistance at 75, 150 and 300 Pa, evaluated by active anterior rhinomanometry. We also investigated subjective symptom scores (0–3) of nasal, eye. and lung symptoms. It can be shown that the nasal flow under astemizole treatment is statistically significantly higher than the nasal flow under placebo treatment ( P = 0.034). This is in accordance with the findings in subjective nasal itching and sneezing.     

Topical corticosteroid inhibits interleukin-4, -5 and -13 in nasal secretions following allergen challenge

BACKGROUND: Cytokines and chemokines produced by allergen-reactive T-helper type 2 (Th2) cells may be pivotal to the pathophysiology of allergic disorders. OBJECTIVE: This study was performed to assess the effect of 7 days of topical corticosteroid on nasal allergen challenge (NAC) in terms of eosinophils, cytokines and chemokines obtained by nasal lavage and filter paper methods. METHODS: Patients with grass pollen seasonal-allergic rhinitis (n = 13) out of season received nasal challenge following matched placebo (twice daily into each nostril for 7 days) and fluticasone propionate (100 microg twice daily into each nostril for 7 days). Chemokine and cytokine levels were analysed using a sensitive automated bead immunoassay system at intervals up to 8 h after NAC. RESULTS: Levels of cytokines and chemokines from filter paper were generally higher than from nasal lavage. Fluticasone propionate caused a reduction in symptoms, total leukocyte counts and eosinophils, and abrogation of IL-4, IL-5, IL-6 and IL-13 responses in the filter paper taken in the late phase (P < 0.05 for IL-4 and IL-13, P < 0.01 for IL-5 and IL-6). Levels of chemokines (eotaxin, RANTES, MCP-1, MIP-1alpha, IL-8 and IP-10) were also reduced in the late phase (P < 0.01 at 8 h). However, levels of IL-2, IL-3, IL-7, IL-12 (p40 and p70), -15, TNF-alpha, IFN-gamma and GM-CSF were not affected. CONCLUSION: Fluticasone propionate has selective inhibitory effects on Th2 cytokine synthesis following nasal challenge, while also decreasing release of chemokines, but not affecting levels of Th1 cytokines.     

Retrospective study on fluticasone propionate aqueous nasal spray efficacy in patients with allergic rhinitis: evaluation of clinical and laboratory parameters

BACKGROUND: In allergic rhinitis, allergenic stimulation causes the release of various mediators that induce symptoms and the development of chronic inflammation, which, in turn, is caused by cells involved in the late phase of inflammation, such as eosinophils. The eosinophils also cause damage at the mucosal level through the secretion of eosinophil cationic protein and other preformed factors contained in their granules. The objective was to verify the efficacy of fluticasone propionate aqueous nasal spray in patients with allergic rhinitis; in a retrospective study, we have evaluated mediators of inflammation, making correlations with the clinical symptoms score during and outside the pollen season. METHODS: Forty patients with allergic rhinitis and 15 normal controls were included in our study. Eosinophil cationic protein, eosinophil chemotactic activity, and blood and nasal lavage eosinophil count were evaluated as laboratory parameters. RESULTS: We found a significant increase in nasal lavage levels of eosinophil cationic protein in allergic patients, and this was strictly correlated with the clinical symptoms score. No differences were found in the eosinophil count of allergic patients and in the serum eosinophil cationic protein of patients sensitized to seasonal allergens in comparison with normal subjects. By contrast, an increase in serum eosinophil cationic protein level was found in patients sensitized to perennial allergens. After topical administration of fluticasone propionate aqueous nasal spray, a reduction in nasal lavage eosinophil cationic protein secretion was obtained with a reduction of eosinophil chemotactic activity at the local level. This reduction correlated with an improvement of clinical symptoms. CONCLUSIONS: The clinical improvement and reduction in nasal lavage eosinophil cationic protein and eosinophil chemotactic activity after administration of fluticasone propionate aqueous nasal spray further confirms the role of this treatment in allergic rhinitis.     

Efficacy and onset of action of fluticasone propionate aqueous nasal spray on nasal symptoms, eosinophil count, and mediator release after nasal allergen challenge in patients with seasonal allergic rhinitis

We studied the effect and onset of action of fluticasone propionate aqueous nasal spray (FPANS) on mediator release and eosinophil accumulation in nasal secretions and on nasal symptoms of patients with seasonal allergic rhinitis after nasal allergen challenge (NAC). At the end of the pollen season, 28 patients were randomized in a double-blind and crossover design to receive 7 days' treatment with FPANS (200 μg, once daily) and matching placebo. NACs were performed before and at 6 h and 1. 2. 3. and 7 days during treatment with FPANS or placebo. Nasal secretions were collected for a quantitative determination of mediators and eosinophil count before and 5 min after each challenge. Nasal symptoms were assessed by scales grading the severity of symptoms at the same time. Results showed that for mediator concentrations there was a significant decrease of leukotriene C4 (P<0.001) at 7 days after the first administration of FPANS as compared to placebo. Two days after FPANS. both eosinophil counts and eosinophil cationic protein (ECP) concentrations were lower than those of placebo (eosinophils; f=0.032; ECP; F=0.038). The onset became even more important at day 7 (eosinophils; P=0.001; ECP; P=0.009) during the FPANS treatment period. For the subjective nasal symptoms, a significant reduction of symptom scores for nasal obstruction occurred also at day 3 (F=0.017) and for sneezing at day 7 (f=0.003). There was not yet any significant improvement of the objective nasal airway resistance after the different NACs during the study period. In conclusion, this study demonstrated that topical fluticasone propionate is effective in the treatment of mucosal inflammation induced by NAC. For optimal control of nasal symptoms induced by repeated maximal allergen challenges, a treatment period of more than 1 week is required.     

Nasal nitric oxide: longitudinal reproducibility and the effects of a nasal allergen challenge in patients with allergic rhinitis

BACKGROUND: Exhaled nitric oxide (eNO) is a validated noninvasive marker of airway inflammation in asthma. In patients with allergic rhinitis (AR), increased levels of nasal nitric oxide (nNO) have also been measured. However, the applicability of nNO as a marker of upper airway inflammation awaits validation. AIM: To test the longitudinal reproducibility of standardized nNO measurements in patients with AR and the effects of nasal allergen challenge. METHODS: Twenty patients with clinically stable, untreated AR participated in a combined study design. First, reproducibility of nNO was tested over 1, 7, and 14-21 days. Subsequently, the effect of nasal allergen challenge on nNO was studied in a placebo-controlled, parallel design. Nasal NO was measured with a chemoluminescence analyzer. Ten subjects randomly underwent a standardized nasal allergen challenge; 10 subjects received placebo. Response to nasal challenge was monitored by composite symptom scores. RESULTS: There was a good reproducibility of nNO up to 7 days [coefficient of variation (CV) over 1 (16.45%) and 7 days (21.5%)], decreasing over time [CV (14-21 days): 38.3%]. As compared with placebo, allergen challenge caused a significant increase in symptom scores (P < 0.001), accompanied by a decrease in nNO at 20 min postchallenge (P = 0.001). Furthermore, there was a gradual increase in nNO at 7 h, reaching significance at 24-h postallergen (P = 0.04). CONCLUSIONS: Similar to eNO in asthma, nNO is a noninvasive marker, potentially suitable to monitor upper airway inflammation following allergen-induced late response. Present data show a good reproducibility of nNO measurements, decreasing over time, probably because of subclinical seasonal influences.     

Effects of a reversible β-tryptase and trypsin inhibitor (RWJ-58643) on nasal allergic responses

BACKGROUND: beta-Tryptase is a multifunctional mast cell serine protease released during mast cell degranulation and tryptase/trypsin inhibitors are a novel potential therapeutic approach for allergic inflammatory diseases. OBJECTIVES: This study was performed to assess the effects of RWJ-58643 on nasal symptoms, eosinophil influx, and cytokine and chemokine release following nasal allergen challenge (NAC). METHODS: Male patients with grass pollen allergic rhinitis (n=16) out of season received single doses of RWJ-58643 (100, 300, 600 microg) or matched placebo given 30 min before NAC in a double-blind, randomized crossover design. A single dose of 200 microg budesonide was studied in an open-label extension phase. NAC was performed with Timothy grass pollen (ALK) via a nasal device, and nasal lavage was performed at times 0 (pre-drug, pre-allergen), 0.5 (30 min post-drug, pre-NAC) 1.5, 2.5, 4.5, 6.5, 8.5, and 24 h after drug administration. Nasal lavage mediators were analysed using a sensitive multiplexed bead immunoassay system. RESULTS: Low-dose RWJ-58643 (100 microg) and budesonide (200 microg) significantly reduced symptoms, eosinophils and levels of IL-5 following NAC. However, higher doses of RWJ-58643 (300 and 600 microg) caused a late eosinophilia and preceding increases in IL-5 compared with placebo. CONCLUSIONS: This study suggests that combined beta-tryptase and trypsin inhibition has therapeutic potential in allergic inflammation, however, this property is dose responsive and higher doses are ineffective and may cause eosinophilia.     

Sinus CT scans and mediator release in nasal secretions after nasal challenge with cypress pollens

BACKGROUND: Involvement of paranasal sinuses has been suggested in allergic rhinitis but not clearly demonstrated. AIMS: To investigate the relationship between intermittent allergic rhinitis and computerized tomography (CT). METHODS: Twenty patients with intermittent rhinitis and sensitized to cypress pollens underwent unilateral nasal provocation tests (NPTs) using increasing concentrations of cypress pollens out of the pollen season. Sinus CT-scans were carried out just before a NPT and 24 h later. Nasal lavage was carried out just before a NPT, 30 min after a positive challenge and again 24 h later. Leucotriene C4/D4, intracellular adhesion molecule-1 and eosinophil cationic protein were measured in nasal secretions. RESULTS: Thirteen patients (65%) showed an alteration in their CT-scans after allergen challenge. Ten of them showed sinus changes controlateral to their allergenic provocation. Radiological changes mainly affected the osteomeatal complex and the ethmoid sinuses. Pre-existing abnormalities (13 of 20 cases) mainly concerned the maxillary sinuses. There was no correlation between CT-scan abnormalities and levels of mediators released in nasal secretions. CONCLUSIONS: We have shown that nasal allergen challenge can produce radiological changes in the paranasal sinuses. This mainly concerned the ethmoid sinuses.     

Effect of nasal allergen challenge on serotonin, substance P and vasoactive intestinal peptide in plasma and nasal secretions

We have studied the changes in concentration of serotonin, substance P, and vasoactive intestinal peptide (VIP) in plasma following a nasal allergen provocation in 14 grass pollen-allergic subjects; in five the urinary excretion of serotonin and 5-hydroxy-indolyl-acetic acid (5-HIAA) was also measured. In addition, the concentration of serotonin and substance P was measured in nasal secretions following nasal challenge with allergen and methacholine. The results showed an allergen-induced increase in free plasma serotonin (P less than 0.01) and no change in platelet serotonin, urinary serotonin and urinary 5-HIAA. The plasma substance P level tended to fall (P greater than 0.1), while plasma VIP increased significantly (P less than 0.02). In nasal secretions, there were measurable levels of serotonin in all samples and of substance P in all but one. There was no difference between the concentrations of serotonin and substance P in secretions collected after allergen challenge and after methacholine challenge. For both substances, the secretion median value was comparable to that of plasma. Symptom reduction by topical and systemic pretreatment with a serotonin- and VIP-antagonist before nasal allergen provocation is necessary to define the role of these two agents in allergic rhinitis.