Allergen-induced Nasal Symptoms Research Articles

The effects of an H3 receptor antagonist (PF-03654746) with fexofenadine on reducing allergic rhinitis symptoms

Nasal H(3) receptors might have a role in mediating the effects of histamine in patients with allergic rhinitis. This study explored the effect of the potent oral H(3) receptor antagonist PF-03654746 in combination with an oral H(1) receptor antagonist on the objective (acoustic rhinometry) and subjective (symptoms) responses to nasal allergen challenge. Twenty patients with out-of-season allergic rhinitisdisplaying a 30% or greater decrease in minimum nasal cross-sectional area (A(min)) after bolus (ragweed) complete nasal allergen challenge at screening were studied by using a randomized, double-blind, single-dose, 4-way crossover design. Treatments included 10 mg of PF-03654746 plus 60 mg of fexofenadine (group 1), 1 mg of PF-03654746 plus 60 mg of fexofenadine (group 2), 60 mg of fexofenadine/120 mg of pseudoephedrine (group 3), and placebo (group 4). After dosing, subjects underwent complete nasal allergen challenge. Nasal symptom scores (no. of sneezes and 0- to 5-point scores for severity of congestion, itching, and rhinorrhea), A(min) (in square centimeters), and nasal volume (in cubic centimeters) were recorded 15, 30, 45, and 60 minutes after allergen. There was a minimum 10-day washout between periods. The following symptom scores were significantly (P≤.05) reduced by active treatments versus placebo: group 1, congestion of -0.7 (SE, 0.3), itching of -1.0 (SE, 0.3), rhinorrhea of -1.3 (SE, 0.3), and sneeze of -8.8 (SE, 1.5); group 2, itching of -0.6 (SE, 0.3), rhinorrhea of -0.8 (SE, 0.3), and sneeze of -9.1 (SE, 1.5); and group 3, rhinorrhea of -0.7 (SE, 0.3) and sneeze of -7.0 (SE, 1.5). There was no significant effect of any treatment on mean A(min) proportion or nasal volume proportion after nasal allergen challenge. In combination with fexofenadine, single doses of PF-03654746 caused a reduction in allergen-induced nasal symptoms. H(3) receptor antagonism might be a novel therapeutic strategy to further explore in patients with allergic rhinitis.

Leukotriene D4 increases the excitability of capsaicin‐sensitive nasal sensory nerves to electrical and chemical stimuli

Clinical studies have demonstrated significant reductions in allergen-induced nasal symptoms of atopic rhinitis subjects by CysLT1 antagonists, including neuronally mediated symptoms such as sneeze, itch and reflex hypersecretion. Here, we test the hypothesis that cysteinyl leukotrienes activate and/or alter the activity of nasal nociceptive (capsaicin-sensitive) sensory neurones. Using retrograde tracer (DiI), we labelled guinea-pig trigeminal sensory neurones that projected fibres to the nasal mucosa. Single-neurone reverse transcriptase (RT)-PCR was used to evaluate CysLT receptor gene expression. The effect of cysteinyl leukotrienes on individual nasal sensory nerve activity was assessed in Ca2+ assays and whole-cell gramicidin-perforated patch-clamp studies. Nasal C-fibre neurones express CysLT1 but not CysLT2 mRNA. LTD4 and LTC4 increased intracellular [Ca2+]free in a population of capsaicin-sensitive trigeminal nerves, an effect blocked by the CysLT1 antagonist ICI198615. In current clamp mode, LTD4 had no effect on resting membrane potential. However, LTD4 significantly increased electrical excitability (action potential discharge during current pulses) threefold in capsaicin-sensitive nasal neurones, which was inhibited by CysLT1 antagonists ICI198615 and montelukast. LTD4 had no effect on electrical excitability in capsaicin-insensitive neurones. Finally, LTD4 significantly augmented histamine-induced responses in capsaicin-sensitive neurones as measured by increased action potential discharge, peak frequency and membrane depolarization. LTD4, likely through CysLT1 receptors, directly increases the excitability of capsaicin-sensitive guinea-pig nasal trigeminal neurones, demonstrating a novel mechanism for the actions of cysteinyl leukotrienes and potentially explains the effectiveness of CysLT1 antagonists in treating nasal allergen-induced neuronal symptoms.

The effects of the nasal antihistamines olopatadine and azelastine in nasal allergen provocation

Olopatadine, an antihistamine used in allergic conjunctivitis, is under development as a nasal preparation for the treatment of allergic rhinitis. To evaluate the efficacy of olopatadine in suppressing symptoms and biomarkers of the immediate reaction induced by nasal allergen provocation and to compare olopatadine with azelastine in the same model. The study was approved by the Johns Hopkins University institutional review board, and all subjects gave written consent. We studied 20 asymptomatic subjects with seasonal allergic rhinitis. The study had 2 randomized, double-blind, placebo-controlled, crossover phases that evaluated 2 concentrations of olopatadine, 0.1% and 0.2%. In a third exploratory phase, olopatadine, 0.1%, was compared with topical azelastine, 0.1%, in a patient-masked design. Efficacy variables were the allergen-induced sneezes, other clinical symptoms, and the levels of histamine, tryptase, albumin, lysozyme, and cysteinyl-leukotrienes (third study only) in nasal lavage fluids. Both concentrations of olopatadine produced significant inhibition of all nasal symptoms, compared with placebo. Olopatadine, 0.1%, inhibited lysozyme levels, but olopatadine, 0.2%, inhibited histamine, albumin, and lysozyme. The effects of olopatadine, 0.1%, were comparable to those of azelastine, 0.1%. Olopatadine, at 0.1% and 0.2% concentrations, was effective in suppressing allergen-induced nasal symptoms. At 0.2%, olopatadine provided evidence suggestive of inhibition of mast cell degranulation.

Prolonged Allergen Challenge in Murine Nasal Allergic Rhinitis: Nasal Airway Remodeling and Adaptation of Nasal Airway Responsiveness

Nasal airway remodeling exists in allergic rhinitis, but it appears to be far less extensive than in asthma. However, there has been little study about nasal airway remodeling and no study using mice models. It has been reported that airway hyperresponsiveness decreased after prolonged allergen challenge in a chronic murine asthma model together with the progression of remodeling. However, there has been no study of the relation of remodeling and airway responsiveness in nasal allergy. Therefore, we have undertaken this investigation to characterize nasal airway structural changes after prolonged allergen challenge and to examine the relationship between nasal airway hyperresponsivity and remodeling. We prepared murine allergic rhinitis for ovalbumin. Mice were subsequently challenged three times a week with ovalbumin from day 19 to days 53, 88, and 130. We examined allergen-induced nasal symptoms and objective nasal hyperresponsiveness using the enhanced pause system. Moreover, the pathologic changes were investigated after allergen challenge. The extended allergen challenge protocol caused significant nasal airway remodeling. Specifically, remodeling was characterized by goblet cell hyperplasia and deposition of collagen in the submucosal area. Allergen-induced nasal hyperresponsiveness was first increased but gradually decreased in nasal symptoms and Penh after prolonged allergen challenge. We have demonstrated that a remodeling of nasal mucosa in a murine allergic rhinitis model prolonged allergen exposure. Moreover, prolonged allergen exposure induced a reduction of nasal hyperresponsiveness together with a progression of nasal remodeling.

The potential of active metabolites of antihistamines in the management of allergic disease.

Since the discovery of histamine in the ®rst decade of the 20th century, there has been increasing evidence that this biogenic amine, synthesized predominantly in mast cells and basophils, is released in in ammatory processes and plays a key role in the pathogenesis of urticaria and allergic airway diseases, including asthma, rhinitis, and urticaria (1±3). Studies have demonstrated that histamine levels are signi®cantly increased in the bronchoalveolar lavage (BAL) of symptomatic asthmatics, compared with asymptomatic asthmatics (4, 5), and that allergen challenge leads to a marked increase in the levels of histamine in asthmatics (6, 7). Similarly, studies have demonstrated that allergen challenge also leads to signi®cant increases in the levels of histamine in the nasal secretions of patients with allergic rhinitis (8±10). A comparison of patients with chronic urticaria and healthy subjects has also demonstrated that the former release greater amounts of histamine, both spontaneously and after antigen provocation (11±13). In addition, some studies have demonstrated that the responsiveness of the skin to histamine is slightly increased in patients with urticaria (11). Mechanistic studies have demonstrated that the action of histamine arises from its interaction with one of at least three speci®c histamine receptors, H1, H2, and H3, located on various histamine-responsive target tissues. Interaction of histamine with the H1 receptor leads primarily to smooth-muscle contraction, vasodilatation and hypotension, increased vascular permeability with formation of tissue oedema, increased respiratory mucus secretion, and parasympathetic nerve stimulation (14, 15). These effects can subsequently lead to bronchial obstruction in asthma; nasal blockage, sneezing, itching, and discharge in rhinitis; and itchy skin wheals/ ares in urticaria. At the cellular level, histamine may also act on in ammatory cells and lead to release of mediators, such as leukotrienes and cytokines, and increased expression of class II antigens (HLA-DR) and ICAM-1 on epithelial cells (16, 17), effects which could, in turn, exacerbate the pathology and symptoms of allergic disease. In contrast, effects attributable to H2 receptors include augmentation of gastric acid secretion and increases in gastric and respiratory mucus secretion (14). H3 receptors have been implicated in autocrine regulation of histamine synthesis and release from nerve tissue (14).

鼻アレルギー患者の鼻粘膜表層細胞におけるβ受容体機能

The purpose of this study was to investigate the jS-adrenergic function on the nasal mucosa of the patients with allergic rhinitis who showed positive skin test, positive provocation test and eosinophilia in their nasal secretion.The cells, which were scraped from the mucous blanket on the nasal mucosa using a small curette, released histamine after the challenge of allergen (×10 house dust), but this release was inhibited 5 minutes after incubation with 10-4 or 10-5M of 1-isoproterenol. The cells from mucous blanket were also incubated in the Tris ACM buffer with or without 10-5M of 1-isoproterenol, and cyclic AMP levels in the cells were measured using radio-immunoassay. The levels of cyclic AMP incubated with 1-isoproterenol were four times higher than those without 1-isoproterenol.Nasal provocation was performed using the disk method. Nasal resistance was measured by the combined rhinomanometry and sneezes, nasal secretion and swelling of the turbinate were observed for 5 minutes after provocation. The increase of nasal airway resistance and allergen-induced nasal symptoms caused by provocation was inhibited after spraying 1-isoproterenol. This responsiveness to 1-isoproterenol as Radrenostimulant suggested that the adenyl cyclase activity and adrenoceptor function of the cells on the nasal mucosa were normal in the patients with nasal allergy.

Inhibition of the immediate allergic reaction in the nose by the beta-2 adrenostimulant fenoterol

Sympathomimetic agents inhibit antigen-induced release of histamine in animal experiments and in in vitro studies of human tissue, but the significance of this effect for treatment of allergic airway diseases has not been established. It was the aim of our study to investigate the protective effect of the beta-2 adrenostimulant fenoterol on allergen-induced nasal symptoms and to relate the efficacy to dose and time. In a double-blind crossover design 16 patients with hay fever were challenged with grass pollen extract in the nose after pretreatment with intranasal placebo and fenoterol in different doses, delivered as a micronized powder from a pressurized canister and as a watery solution from a pump spray. Sneezing was recorded, and rhinorrhea and changes in nasal airway resistance were measured for 15 min after the provocation. Fenoterol, micronized powder as well as solution, had a marked inhibitory effect on all three nasal symptoms (p < 0.05) in doses ordinarily used for inhalation in the treatment of branchial asthma. The effect lasted for more than 4 hr. Our study has suggested that topical application of beta-2 adrenostimulants has a mast cell stabilizing effect in the airways and that these drugs may be of value for treatment of allergic rhinitis.